CN118807058A

CN118807058A - Patient interface

Info

Publication number: CN118807058A
Application number: CN202410459970.1A
Authority: CN
Inventors: 安德烈·范沙尔克维克; 凯文·彼得·奥唐纳; 恩里科·阿尔瓦雷斯·加西亚; 伊万·贾斯图斯·拉德米耶
Original assignee: Fisher and Paykel Healthcare Ltd
Current assignee: Fisher and Paykel Healthcare Ltd
Priority date: 2023-04-18
Filing date: 2024-04-17
Publication date: 2024-10-22

Abstract

The present application relates to patient interfaces. The nasal interface (2900) has an interface body (2910) with a nasal delivery element (2911). The nasal delivery element is configured to seal with a nostril of a patient. The nasal interface has a gas inlet (2921) for delivering respiratory gases into the nasal interface. The gas inlet and the nasal delivery element are in fluid communication with a gas flow passage (2925) of the interface body to deliver breathing gas from the gas inlet through the nasal delivery element. The gas inlet has a portion (2921 p) extending outside the interface body. The portion is in a fixed position offset relative to a Midline Plane (MP) bisecting the nasal interface and is angled obliquely relative to the midline plane to position an opening (2921 o) of the gas inlet away from the midline plane.

Description

Patient interface

The present application claims priority from U.S. provisional application 63/496,838, entitled "patient interface" ("PATIENT INTERFACE") filed on 18, 4, 2023, and U.S. provisional application 63/597,649, entitled "patient interface" ("PATIENT INTERFACE"), filed on 9, 11, 2023, the entire contents of which are incorporated herein by reference.

Technical Field

The present disclosure relates generally to patient interfaces for delivering respiratory gases to the airways of a patient.

Background

The humidifier is used to provide humidified breathing gas to a patient. The gas is delivered to the patient via the patient interface. Examples of patient interfaces include masks, nasal cannulas, combinations of masks and nasal masks, and the like.

A patient interface including a nasal interface may be used to deliver airflow to a patient. The nasal delivery element is inserted into the patient's nose to deliver the desired treatment. The nasal delivery element may or may not need to be sealed or semi-sealed at the nose to deliver the treatment.

Disclosure of Invention

In accordance with certain features, aspects, and advantages of at least one embodiment disclosed herein, a nasal interface is disclosed, comprising:

An interface body comprising a nasal delivery element, wherein the nasal delivery element is configured to seal with a nostril of a patient,

And a gas inlet for delivering respiratory gas into the nasal interface, wherein the gas inlet and the nasal delivery element are in fluid communication with the gas flow path of the interface body for delivering respiratory gas from the gas inlet through the nasal delivery element,

Wherein the gas inlet has a portion extending outside the interface body, wherein the portion is in a fixed position offset relative to a midline plane bisecting the nasal interface and is angled obliquely relative to the midline plane to position the opening of the gas inlet away from the midline plane.

In some constructions, an end of the portion adjacent the gas flow passage is offset from the midline plane by a distance of about 40mm, optionally by a distance of between about 10mm and about 40 mm.

In some constructions, the portion is obliquely angled between about 10 degrees and about 70 degrees relative to the midline plane at greater than 0 degrees and up to about 70 degrees, optionally relative to the midline plane.

In some configurations, the nasal delivery element comprises a first nasal delivery element, wherein the interface body comprises a second nasal delivery element configured to seal with a respective nostril of the patient, wherein the second nasal delivery element is in fluid communication with the gas inlet via the gas flow path, and wherein the first nasal delivery element and the second nasal delivery element each comprise a base and an outlet.

In some constructions, the portion is at an angle greater than 0 degrees and up to about 40 degrees relative to a second plane extending through the first and second nasal delivery elements from a base to an outlet of the first and second nasal delivery elements.

In some configurations, the gas inlet includes an opening into the gas flow passage of the interface body, and wherein the opening is configured to direct an incoming gas flow from the gas inlet toward the base of the nasal delivery element.

In some configurations, the gas inlet comprises an opening in the gas flow channel into the interface body, and wherein the opening is configured to direct more of the incoming gas flow toward the base of the first nasal delivery element than toward the base of the second nasal delivery element.

In some configurations, the gas inlet comprises an opening into the gas flow channel of the interface body, and wherein the opening is configured to direct an incoming gas flow toward a chamber wall between the base of the first nasal delivery element and the base of the second nasal delivery element.

In some constructions, the interface body includes a first interface body side arm and a second interface body side arm, wherein the first interface body side arm and the second interface body side arm each include an unsealed lumen to enhance flexibility of the first interface body side arm and the second interface body side arm.

In some constructions, each interface body side arm includes a patient proximal wall configured to contact, in use, a patient cheek and a patient distal wall configured to be spaced apart, in use, from the patient cheek, wherein the patient proximal wall is spaced apart from the patient distal wall with an unsealed lumen therebetween.

In some constructions, the interface body includes first and second interface body side arms, the patient interface includes a frame having first and second frame side arms, wherein the first and second interface body side arms each include a through-channel such that a corresponding one of the first and second frame side arms can extend through the through-channel to couple the first and second frame side arms with the first and second interface body side arms, wherein when the first and second frame side arms are coupled with the first and second interface body side arms, a proximal portion of the first and second interface body side arms is located behind a proximal portion of the first and second frame side arms to be positioned between the patient's face and the proximal portions of the first and second frame side arms in use.

In some constructions, the interface body includes a softer material than the frame including a more rigid material.

In some constructions, the first and second interface body side arms each include a respective compliant cheek.

In some constructions, each through channel is positioned adjacent an outer end of a respective interface body side arm.

In some constructions, each through passage includes a hole or slit.

In some configurations, the nasal interface is configured to create an asymmetric airflow at the patient's nostrils in use.

In some configurations, the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the first nasal delivery element is proximate to the gas inlet and the second nasal delivery element is distal to the gas inlet, wherein the nasal interface is configured to receive an ingress gas from the gas inlet and provide a first flow of gas from the ingress gas configured to be substantially provided to the first nostril of the patient in use and a second flow of gas configured to be substantially provided to the second nostril of the patient in use, and the nasal interface is configured to direct more ingress gas to the first flow of gas than the second flow of gas to create an asymmetric flow of gas at the nasal airway of the patient throughout the respiratory cycle of the patient.

In some configurations, the first nasal delivery element includes a first outlet configured to substantially deliver gas to a first nostril of the patient, and the second nasal delivery element includes a second outlet configured to substantially deliver gas to a second nostril of the patient.

In some configurations, the gas inlet is at least partially aligned with the first outlet and less aligned or misaligned with the second outlet.

In some constructions, the gas inlet is substantially axially aligned with the first outlet.

In some configurations, at least half of the cross-sectional area of the gas inlet is axially aligned with at least half of the cross-sectional area of the first outlet.

In some configurations, the gas inlet includes an outer portion for connection to a breathing conduit providing a flow of gas from a gas source to the interface body, and further includes an inner portion in fluid communication with the interface body.

In some configurations, the inner portion of the gas inlet is at least partially aligned with the first outlet, and in some configurations, the gas inlet is inclined toward the first outlet.

In some configurations, the first air stream has at least one dimension that is greater than a corresponding dimension of the second air stream.

In some configurations, the at least one dimension includes a lateral dimension of the first air stream, and wherein the corresponding dimension includes a lateral dimension of the second air stream.

In some configurations, the diameter, cross-sectional area, and/or volume of the first gas stream is greater than the corresponding diameter, cross-sectional area, and/or volume of the second gas stream.

In some configurations, the ratio of the cross-sectional area of the first air stream to the corresponding cross-sectional area of the second air stream is between about 2:1 and about 5:1, alternatively between about 2:1 and about 4:1, alternatively between about 2.5:1 and about 3.5:1, alternatively about 3:1.

In some constructions, the first outlet and the second outlet comprise substantially the same cross-sectional area.

In some configurations, the nasal interface is configured to deliver a lower flow rate of the airflow through the first outlet than the flow rate of the airflow through the second outlet during the inspiratory phase of the respiratory cycle.

In some configurations, the nasal interface is configured to deliver a higher pressure of the flow of gas through the first outlet than the flow of gas through the second outlet during the inspiratory phase of the respiratory cycle.

In some configurations, the nasal interface includes a flow guide configured to direct more of the incoming gas from the gas inlet to the first gas flow than to the second gas flow.

In some constructions, the nasal interface includes a connector or elbow for connecting the respiratory conduit to the patient interface.

In some constructions, the connector or elbow includes or is a flow guide.

In some configurations, the flow guide portion includes a nozzle configured to accelerate the airflow toward the first outlet or the first outlet portion.

In some configurations, the nasal interface is configured to direct more of the incoming gas to the first gas flow than the second gas flow during the inspiratory phase of the respiratory cycle.

In some constructions, the interface body is a nasal cushion.

In some configurations, the nasal interface is configured to simultaneously deliver, in use, breathing gas from the gas inlet through the interface body to both the first nostril and the second nostril of the patient.

In some configurations, the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface is configured to provide, in use, a greater dynamic pressure at the first nostril of the patient and, in use, a lesser dynamic pressure at the second nostril of the patient to create an asymmetric flow of gas at the nasal airway of the patient throughout the respiratory cycle of the patient.

In some configurations, the nasal interface includes a flow guide configured to direct more of the inlet gas from the gas inlet to the first outlet than to the second outlet.

In some configurations, the flow guide includes a nozzle configured to accelerate the airflow toward the first outlet.

In some configurations, the nasal interface is configured to receive an ingress gas from the gas inlet and to provide a first flow of gas from the ingress gas, the first flow of gas configured to be substantially provided to a first naris of a patient in use, and a second flow of gas configured to be substantially provided to a second naris of the patient in use, and the nasal interface is configured to direct more ingress gas to the first flow of gas than to the second flow of gas.

In some configurations, the nasal interface includes a flow dividing portion configured to divide the flow of gas from the gas inlet unequally into a first flow of gas and a second flow of gas.

In some configurations, the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface comprises a split to split the flow from the gas inlet unequally into a first flow configured to be provided substantially to the first nasal delivery element and a second flow configured to be provided substantially to the second nasal delivery element, wherein the first flow is configured to deliver a greater flow along the first flow than along the second flow to create an asymmetric flow at the nasal airway of the patient throughout the respiratory cycle of the patient.

In some configurations, the gas inlet includes an outer portion for connection to a breathing conduit providing a flow of gas source to the interface body, and further includes an inner portion in fluid communication with the interface body.

In some configurations, an inner portion of the gas inlet is at least partially aligned with the first outlet.

In some constructions, the gas inlet is inclined towards the first outlet.

In some configurations, the at least one dimension comprises a lateral dimension of the first air stream, and wherein the corresponding dimension comprises a lateral dimension of the second air stream.

In some constructions, the first outlet or first outlet portion and the second outlet or second outlet portion comprise substantially the same cross-sectional area.

In some configurations, the nasal interface includes a gas manifold, and the interface body, the gas manifold, and/or the gas inlet include a flow dividing portion.

In some configurations, the flow splitting section includes a wall section that extends toward or into the gas inlet, wherein the first gas flow is located on one side of the wall section and the second gas flow is located on the other side of the wall section.

In some configurations, the diverter extends into the gas inlet and divides the gas inlet into a first gas flow portion on one side of the diverter and a second gas flow portion on the other side of the diverter.

In some constructions, the shunt portion is substantially rigid.

In some constructions, the interface body is a nasal cushion.

In some constructions, the nasal cushion includes a shunt portion, and wherein the shunt portion is configured to move and/or deform when the nasal cushion is compressed.

In some constructions, the diverter includes a first wall portion and a second wall portion.

In some constructions, the first wall portion and the second wall portion are hingedly connected to one another, and wherein the relative angle of the first wall portion and the second wall portion is configured to change upon compression of the nasal cushion.

In some constructions, the first wall portion and the second wall portion overlap each other in a relaxed nose pad state, and wherein the degree of overlap of the first wall portion and the second wall portion increases upon compression of the nose pad.

In some configurations, the nasal interface is configured such that the first airflow is configured to be substantially delivered to the first nasal delivery element and the second airflow is configured to be substantially delivered to the second nasal delivery element, and wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient.

In some configurations, the nasal interface is configured to direct more of the incoming gas to the first gas flow than to the second gas flow during the inspiratory phase of the respiratory cycle.

In some constructions, the interface body is a nasal cushion.

In some constructions, the nasal interface includes a bias flow restrictor comprising at least one aperture for allowing airflow from the nasal interface to flow to the ambient environment.

In some constructions, the flow diverter includes a filter or diffuser to filter or diffuse the gas flowing through the holes.

In some configurations, the nasal interface is configured such that a pressure differential of the airflow through the first outlet or first outlet portion and the second outlet or second outlet portion is higher during the exhalation phase than during the inhalation phase.

In some configurations, the nasal interface is configured to obtain a patient pressure of between about 2cmH ₂ O and about 30cmH ₂ O at the first outlet, or first outlet portion, and the second outlet, or second outlet portion, in use, optionally between about 2cmH ₂ O and about 25cmH ₂ O in use, Optionally between about 2cmH ₂ O and about 20cmH ₂ O in use, optionally between about 2cmH ₂ O and about 15cmH ₂ O in use, Optionally between about 2cmH ₂ O and about 14cmH ₂ O in use, optionally between about 2cmH ₂ O and about 13cmH ₂ O in use, Optionally between about 2cmH ₂ O and about 12cmH ₂ O in use, optionally between about 2cmH ₂ O and about 11cmH ₂ O in use, Optionally between about 2cmH ₂ O and about 10cmH ₂ O in use.

In some configurations, the pressure differential between the first outlet or first outlet portion and the second outlet or second outlet portion is configured to provide an asymmetric flow of gas through the upper airway of the patient of at least about 1 liter per minute (lpm), optionally between about 1lpm and about 5 lpm.

In some configurations, the asymmetric gas flow facilitates cleaning CO ₂ from patient anatomical dead spaces.

In some configurations, the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface comprises a bypass restrictor to provide a pressure drop across the nasal interface between the first nasal delivery element and the second nasal delivery element when gas is delivered from the gas inlet to the first nasal delivery element and the second nasal delivery element such that the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element, and wherein the nasal interface comprises a bias flow restrictor for the flow of gas out of the nasal interface.

In some constructions, the nasal interface includes a gas manifold including a gas flow passage.

In some configurations, the pressure drop across the gas flow path is such that the gas flow from the gas inlet to the first nasal delivery element is greater than the gas flow from the gas inlet to the second nasal delivery element when there is a gas flow from the gas inlet to the first nasal delivery element and the second nasal delivery element.

In some constructions, the bypass restrictor provides a reduced cross-sectional area of a portion of the gas flow passage.

In some configurations, the portion of the gas flow channel is between and/or adjacent to the first and second nasal delivery elements.

In some constructions, the bypass restrictor comprises at least one protrusion extending into the gas flow passage, optionally wherein the bypass restrictor comprises a plurality of protrusions extending into the gas flow passage.

In some configurations, the gas manifold includes proximal bypass protrusions proximate to the first and second nasal delivery elements and/or distal bypass protrusions distal to the first and second nasal delivery elements.

In some configurations, the gas manifold includes both a proximal bypass protrusion and a distal bypass protrusion that in combination define a predetermined bypass dimension for restricted gas flow through the gas manifold between the first and second nasal delivery elements.

In some configurations, the bypass restrictor comprises a beveled leading edge and a beveled trailing edge, the leading and trailing edges defining a bypass restrictor that converges and diverges in the direction of gas flow through the gas manifold from the first nasal delivery element to the second nasal delivery element.

In some configurations, the bias flow restrictor comprises at least one aperture for flowing the airflow from the nasal interface to the ambient environment, optionally wherein the bias flow restrictor comprises a plurality of apertures for flowing the airflow from the nasal interface to the ambient environment.

In some constructions, the nasal interface includes a filter unit between the gas manifold and the bias flow restrictor.

In some configurations, the bias flow restrictor is in fluid communication with the gas manifold, optionally wherein the gas manifold includes or is coupled to the bias flow restrictor, optionally wherein the bias flow restrictor is in fluid communication with the gas manifold but is positioned remote from the gas manifold.

In some configurations, the gas inlet is in fluid communication with the breathing conduit.

In some constructions, the inner diameter of the respiratory conduit is between about 12mm and about 23mm, alternatively greater than about 12mm and up to about 23mm, alternatively greater than 12mm and up to about 22mm, alternatively greater than about 12mm and up to about 21mm, alternatively greater than about 12mm and up to about 20mm, alternatively greater than about 12mm and up to about 19mm, alternatively greater than about 12mm and up to about 18mm, alternatively between about 13mm and about 17mm, alternatively between about 14mm and about 16mm, alternatively about 12mm, alternatively about 13mm, alternatively about 14mm, alternatively about 15mm, alternatively about 16mm, alternatively about 17mm, alternatively about 18mm, alternatively about 19mm, alternatively about 20mm, alternatively about 21mm, alternatively about 22mm, alternatively about 23mm, or alternatively any value between any two of these values.

In some constructions, the gas manifold includes a sealing flange or collar for engagement with the first and second nasal delivery elements.

In some configurations, the bypass restrictor comprises an insert for attachment to the gas manifold.

In some constructions, the first and second nasal delivery elements are attached to or integral with the base of the interface body.

In some constructions, the base is arranged to lie between the patient's face and the gas manifold in use.

In some constructions, the interface body includes two side arms extending laterally from opposite sides of the base.

In some constructions, the nasal interface includes a headgear with ends connected to side arms of the interface body.

In some configurations, the bypass restrictor provides a cross-sectional area of a portion of the gas flow passage and the cross-sectional area of the portion of the gas flow passage is greater than 0 to about 1.5 times the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element.

In some configurations, the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface is configured to create a pressure differential between the first nasal delivery element and the second nasal delivery element when gas is delivered from the gas inlet to both the first nasal delivery element and the second nasal delivery element such that the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element.

In some configurations, the pressure differential is such that when there is a flow of gas from the gas inlet to the first nasal delivery element and the second nasal delivery element, the flow of gas from the gas inlet to the first nasal delivery element is greater than the flow of gas from the gas inlet to the second nasal delivery element.

In some constructions, the inner diameter of the respiratory conduit is between about 12mm and about 23mm, alternatively between about 12mm and about 22mm, alternatively between about 12mm and about 21mm, alternatively between about 12mm and about 20mm, alternatively between about 12mm and about 19mm, alternatively between about 12mm and about 18mm, alternatively between about 13mm and about 17mm, alternatively between about 14mm and about 16mm, alternatively about 12mm, alternatively about 13mm, alternatively about 14mm, alternatively about 15mm, alternatively about 16mm, alternatively about 17mm, alternatively about 18mm, alternatively about 19mm, alternatively about 20mm, alternatively about 21mm, alternatively about 22mm, alternatively about 23mm, or alternatively any value between any two of these values.

In some configurations, when gas is delivered from the gas inlet to both the first nasal delivery element and the second nasal delivery element, the gas flow pressure at the second nasal delivery element is up to about 1cmH ₂ O lower than the gas flow pressure at the first nasal delivery element.

In some configurations, the nasal interface is configured such that a pressure differential of the airflow between the first nasal delivery element and the second nasal delivery element is higher during the inhalation phase than during the exhalation phase.

In some configurations, the nasal interface is configured such that the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element during both the inhalation phase and the exhalation phase.

In some constructions, the nasal interface is configured to obtain a patient pressure of between about 2cmH ₂ O and about 30cmH ₂ O at the first and second nasal delivery elements in use, optionally between about 2cmH ₂ O and about 25cmH ₂ O in use, Optionally between about 2cmH ₂ O and about 20cmH ₂ O in use, optionally between about 2cmH ₂ O and about 15cmH ₂ O in use, Optionally between about 2cmH ₂ O and about 14cmH ₂ O in use, optionally between about 2cmH ₂ O and about 13cmH ₂ O in use, Optionally between about 2cmH ₂ O and about 12cmH ₂ O in use, optionally between about 2cmH ₂ O and about 11cmH ₂ O in use, Optionally between about 2cmH ₂ O and about 10cmH ₂ O in use.

In some configurations, the pressure differential between the first nasal delivery element and the second nasal delivery element is configured to provide an asymmetric flow of gas through the upper airway of the patient of at least about 1 liter per minute (lpm), optionally between about 1lpm and about 5 lpm.

In some configurations, the nasal interface includes a bypass restrictor that provides a cross-sectional area of a portion of the gas flow path and the cross-sectional area of the portion of the gas flow path is greater than 0 to about 1.5 times the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element.

In some configurations, the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface comprises at least one gas restrictor that restricts a flow of gas through the nasal interface such that when gas is delivered from the gas inlet to the first nasal delivery element and the second nasal delivery element, a pressure at the first nasal delivery element is higher than a pressure at the second nasal delivery element.

In some configurations, the at least one gas flow restrictor comprises a bypass flow restrictor to provide a pressure drop between the first and second nasal delivery elements through the gas flow path when gas is delivered from the gas inlet to the first and second nasal delivery elements such that the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element.

In some constructions, the nasal interface includes a gas manifold component that includes a gas flow path.

In some configurations, the bypass restrictor provides a cross-sectional area of a portion of the gas flow passage and the cross-sectional area of the portion of the gas flow passage is greater than 0 times to about 1.5 times the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element.

In some configurations, the nasal interface includes a gas flow passage in the gas manifold component, wherein the bypass restrictor provides a reduced cross-sectional area of a portion of the gas flow passage.

In some configurations, the gas manifold component includes proximal bypass protrusions proximate to the first and second nasal delivery elements and/or distal bypass protrusions distal to the first and second nasal delivery elements.

In some configurations, the gas manifold component includes both a proximal bypass protrusion and a distal bypass protrusion that in combination define a predetermined bypass dimension for restricted gas flow through the gas manifold between the first and second nasal delivery elements.

In some configurations, the bypass restrictor comprises an angled leading edge and an angled trailing edge, the leading and trailing edges defining a bypass restrictor that converges and diverges in the direction of flow of the gas flow through the gas manifold from the first nasal delivery element to the second nasal delivery element.

In some constructions, the bypass restrictor comprises an insert for attachment to the gas manifold component.

In some constructions, the nasal interface further comprises a bias flow restrictor for the flow of air out of the nasal interface.

In some constructions, the nasal interface includes a filter unit between the gas manifold component and the bias flow restrictor.

In some configurations, the bias flow restrictor is in fluid communication with the gas manifold component, optionally wherein the gas manifold comprises or is coupled to a bias flow restrictor, optionally wherein the bias flow restrictor is in fluid communication with the gas manifold component but is positioned remote from the gas manifold component.

In some constructions, the gas manifold component includes a sealing flange or collar for engaging the first and second nasal delivery elements when the interface body component is engaged with the gas manifold component.

In some configurations, the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the first nasal delivery element is proximal to the gas inlet and the second nasal delivery element is distal to the gas inlet, wherein the nasal interface comprises a bypass restrictor providing a cross-sectional area of a portion of the gas flow path, wherein the first nasal delivery element and the second nasal delivery element each comprise an internal cross-sectional area, wherein the internal cross-sectional areas together provide a combined cross-sectional area of the first nasal delivery element and the second nasal delivery element, and wherein the cross-sectional area of the portion of the gas flow path is greater than 0 to about 1.5 times the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element.

In some configurations, the cross-sectional area of the portion of the gas flow channel is up to about 1.3 times the combined cross-sectional area of the first and second nasal delivery elements, alternatively up to about 1 times the combined cross-sectional area of the first and second nasal delivery elements, alternatively up to about 2/3 of the combined cross-sectional area of the first and second nasal delivery elements, alternatively up to about 1/2 of the combined cross-sectional area of the first and second nasal delivery elements, alternatively up to about 2/5 of the combined cross-sectional area of the first and second nasal delivery elements, alternatively up to about 1/3 of the combined cross-sectional area of the first and second nasal delivery elements.

In some configurations, the inner cross-sectional area of each of the first and second nasal delivery elements is at a minimum lateral dimension of the respective nasal delivery element.

In some constructions, the minimum transverse dimension is in a direction transverse to a direction of airflow through the first and second nasal delivery elements.

In some configurations, the inner cross-sectional area of each of the first and second nasal delivery elements is at the outlet of the respective nasal delivery element.

In some configurations, the bypass flow restrictor includes a beveled leading edge and a beveled trailing edge that define a bypass flow restrictor that converges and diverges in the direction of gas flow through the gas manifold from the first nasal delivery element to the second nasal delivery element.

In some constructions, the nasal interface includes an interface body and a gas manifold component, wherein the interface body and the gas manifold component together form a gas manifold.

In some constructions, the gas inlet is on one side of the gas manifold.

In some constructions, the open area for gas flow through the bias flow restrictor is between about 10mm ² and about 30mm ², optionally between about 25mm ² and about 30mm ², and optionally about 27.5mm ².

In some constructions, the open area for gas flow through the bias flow restrictor is greater than 0mm ² to about 40mm ², optionally between about 2mm ² and about 40mm ², optionally between about 2mm ² and about 5mm ², optionally between about 12mm ² and about 40mm ², optionally between about 20mm ² and about 30mm ².

In some configurations, the bias flow restrictor is configured such that when, in use, a pressure of greater than 0cmH ₂ O up to about 30cmH ₂ O is provided to the gas inlet and the first and second nasal delivery elements are occluded, the flow rate of the gas stream exiting the nasal interface through the bias flow restrictor is greater than 0lpm to about 80lpm.

In some configurations, the bias flow restrictor is configured such that when a pressure of between about 3cmH ₂ O and about 10cmH ₂ O is provided to the gas inlet in use and the first and second nasal delivery elements are blocked, the flow of gas flow out of the nasal interface through the bias flow restrictor is between about 4lpm and about 15 lpm.

In some configurations, the bias flow restrictor is configured such that when a pressure of between about 4cmH ₂ O and about 30cmH ₂ O is provided to the gas inlet in use and the first and second nasal delivery elements are blocked, the flow of gas flow out of the nasal interface through the bias flow restrictor is between about 15lpm and about 80 lpm.

In some configurations, the bias flow restrictor comprises at least one aperture for flowing gas from the nasal interface to the ambient environment, optionally wherein the bias flow restrictor comprises a plurality of apertures for flowing gas from the nasal interface to the ambient environment.

In some configurations, the cross-sectional area of the portion of the gas flow channel is between about 10% and up to about 100% of the first cross-sectional area of the adjacent portion of the gas flow channel, alternatively more than about 10% and less than 100% of the first cross-sectional area, alternatively up to about 90% of the first cross-sectional area, alternatively up to about 80% of the first cross-sectional area, alternatively up to about 70% of the first cross-sectional area, alternatively up to about 60% of the first cross-sectional area, alternatively up to about 55% of the first cross-sectional area, alternatively up to about 40% of the first cross-sectional area, alternatively up to about 30% of the first cross-sectional area, and alternatively up to about 25% of the first cross-sectional area.

In some constructions, the cross-sectional area of the portion of the gas flow passage is up to about 300mm ², alternatively up to about 280mm ², alternatively up to about 270mm ², alternatively up to about 200mm ², alternatively up to about 160mm ², alternatively up to about 110mm ², alternatively up to about 80mm ², alternatively up to about 60mm ², and alternatively up to about 50mm ².

In some constructions, the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element is greater than 0mm ² and up to about 250mm ², optionally between about 1mm ² and about 250mm ², optionally between about 1.6mm ² and about 250mm ², optionally between about 50mm ² and about 250mm ², optionally between about 50mm ² and about 200mm ², optionally between about 30mm ² and about 200mm ², optionally between about 30mm ² and about 155mm ², optionally between about 50mm ² and about 155mm ², and optionally between about 70mm ² and about 155mm ².

In some constructions, the cross-sectional area of the portion of the gas flow passage is greater than 0 to about 1.5 times the combined cross-sectional area of the first and second nasal delivery elements, and the combined cross-sectional area of the first and second nasal delivery elements is between about 1mm ² and about 250mm ².

In some constructions, the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element is between about 1.6mm ² and about 250mm ², optionally between about 50mm ² and about 250mm ², optionally between about 50mm ² and about 200mm ², optionally between about 30mm ² and about 200mm ², optionally between about 30mm ² and about 155mm ², optionally between about 50mm ² and about 155mm ², and optionally between about 70mm ² and about 155mm ².

In some configurations, the bypass restrictor provides a pressure drop across the nasal interface between the first and second nasal delivery elements when gas is delivered from the gas inlet to the first and second nasal delivery elements such that the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element.

In some configurations, the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of a patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via a gas flow path, wherein the first nasal delivery element is proximal to the gas inlet and the second nasal delivery element is distal to the gas inlet,

Wherein the nasal interface includes a bypass restrictor providing a cross-sectional area of a portion of the gas flow path,

Wherein the first nasal delivery element and the second nasal delivery element each comprise an inner cross-sectional area,

And wherein the internal cross-sectional area of the first and second nasal delivery elements and the cross-sectional area of the portion of the gas flow passage are related so as to create, in use, an asymmetric gas flow from the first and second nasal delivery elements.

In some constructions, the internal cross-sectional areas together provide a combined cross-sectional area of the first nasal delivery element and the second nasal delivery element, and wherein the cross-sectional area of the portion of the gas flow passage is greater than 0 to about 1.5 times the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element.

In some constructions, the minimum transverse dimension is in a direction transverse to the direction of gas flow through the first and second nasal delivery elements.

In some configurations, the cross-sectional area of the portion of the gas flow passage is up to about 1 times, optionally up to about 2/3 times, the combined cross-sectional area of the first and second nasal delivery elements, and the nasal interface is configured to provide 20lpm of bias flow through the bias flow restrictor when a pressure of 4cmH ₂ O is provided to the gas inlet and the first and second nasal delivery elements are blocked.

In some configurations, the cross-sectional area of the portion of the gas flow passage is up to about 1 times, optionally up to about 2/3 times, the combined cross-sectional area of the first and second nasal delivery elements, and the nasal interface is configured to provide 32lpm of bias flow through the bias flow restrictor when a pressure of 8cmH ₂ O is provided to the gas inlet and the first and second nasal delivery elements are blocked.

In some constructions, the cross-sectional area of the portion of the gas flow path is up to about 2/3 times the combined cross-sectional area of the first and second nasal delivery elements, and the nasal interface is configured to provide a bias flow through the bias flow restrictor when a pressure of 4cmH ₂ O is provided to the gas inlet and the first and second nasal delivery elements are blocked, or to provide a bias flow through the bias flow restrictor when a pressure of 8cmH ₂ O is provided to the gas inlet and the first and second nasal delivery elements are blocked, or to provide a bias flow through the bias flow restrictor of 32lpm when a pressure of 12cmH ₂ O is applied to the gas inlet and the first and second nasal delivery elements are blocked, or to provide a bias flow through the bias flow restrictor of 48lpm when a pressure of 16cmH ₂ O is applied to the gas inlet and the first and second nasal delivery elements are blocked, or to provide a bias flow through the bias flow restrictor of 53lpm when a pressure of 20cmH ₂ O is applied to the gas inlet and the first and second nasal delivery elements are blocked.

In some constructions, the cross-sectional area of the portion of the gas flow passage is up to about 2/3 times the combined cross-sectional area of the first and second nasal delivery elements, and the nasal interface is configured to provide a bias flow through the bias flow restrictor of 32lpm or more when a pressure of 8cmH ₂ O is provided to the gas inlet and the first and second nasal delivery elements are blocked.

In some constructions, the cross-sectional area of the portion of the gas flow path is up to about 1/3 times the combined cross-sectional area of the first and second nasal delivery elements, and the nasal interface is configured to provide a bias flow through the bias flow restrictor of 32lpm or more when a pressure of 8cmH ₂ O is provided to the gas inlet and the first and second nasal delivery elements are blocked, or wherein the cross-sectional area of the portion of the gas flow path is up to about 2/5 times the combined cross-sectional area of the first and second nasal delivery elements, and the nasal interface is configured to provide a bias flow through the bias flow restrictor of 41lpm or more when a pressure of 12cm H ₂ O is provided to the gas inlet and the first and second nasal delivery elements are blocked, or wherein the cross-sectional area of the portion of the gas flow path is up to about 2/3 times the combined cross-sectional area of the first and second nasal delivery elements, and the nasal interface is configured to provide a bias flow through the bias flow restrictor of 48 or more when a pressure of 16cm H ₂ O is provided to the gas inlet and the first and second nasal delivery elements are blocked.

The nasal interface of this aspect may have one or more features described with respect to any other aspect.

Wherein the nasal delivery element comprises a plurality of windings forming a bellows portion between the gas flow passage and the outlet of the nasal delivery element, an

Wherein the nasal interface is configured to generate an asymmetric airflow at the patient's nares in use.

In some constructions, the interface body includes a flex region, wherein the plurality of windings are located between the flex region and the outlet of the nasal delivery element

In some constructions, the flex region extends around less than the entire perimeter of the nasal delivery element at or near the base of the nasal delivery element.

In some constructions, the flex region extends around at least an anterior, posterior, and laterally inward portion of the perimeter of the nasal delivery element.

In some constructions, the nasal interface includes a frame, wherein the interface body includes a softer material than the frame including a more rigid material, and wherein a portion of the frame contacts the interface body portion adjacent the flex region to reduce or inhibit flexing of the interface body portion adjacent the flex region.

In some configurations, the cross-sectional shape of the coiled portion corresponds to the cross-sectional shape of the base of the outlet portion of the nasal delivery element.

In some configurations, the first and second nasal delivery elements each include a plurality of convolutions forming respective bellows portions between the gas flow passage and the outlet of the respective nasal delivery element.

In some constructions, the interface body includes at least one flex region, wherein the plurality of windings of each nasal delivery element are located between the at least one flex region and the outlet of the respective nasal delivery element.

In some configurations, the at least one flex region comprises two flex regions, wherein the plurality of windings of each nasal delivery element is located between a respective one of the two flex regions and an outlet of a respective nasal delivery element.

In some constructions, the at least one flex region extends around less than the entire perimeter of each nasal delivery element at or near the base of each nasal delivery element.

In some constructions, the at least one flex region extends around at least an anterior, posterior, and laterally inward portion of the perimeter of each nasal delivery element.

In some constructions, the nasal interface comprises a frame, wherein the interface body comprises a softer material than the frame comprising a more rigid material, and wherein a portion of the frame is in contact with the interface body portion adjacent the at least one flex region to reduce or inhibit flexing of the interface body portion adjacent the at least one flex region.

In some configurations, the cross-sectional shape of the coiled portion corresponds to the cross-sectional shape of the base of the outlet portion of the respective nasal delivery element.

In some constructions, the interface body includes first and second interface body side arms, the patient interface includes a frame having first and second frame side arms, wherein the first and second interface body side arms each include a through-channel to enable a respective one of the first and second frame side arms to extend through the through-channel to couple the first and second frame side arms with the first and second interface body side arms, wherein when coupled with the first and second interface body side arms, a proximal portion of the first and second interface body side arms is located behind a proximal portion of the first and second frame side arms for positioning between the patient's face and the proximal portions of the first and second frame side arms in use.

In some constructions, each through passage includes a hole or slit.

In some configurations, the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the first nasal delivery element is proximate to the gas inlet and the second nasal delivery element is distal to the gas inlet, wherein the nasal interface is configured to receive an ingress gas from the gas inlet and provide a first flow of gas from the ingress gas that is configured to be substantially provided to the first nostril of the patient in use and a second flow of gas that is configured to be substantially provided to the second nostril of the patient in use, and the nasal interface is configured to direct more ingress gas to the first flow of gas than the second flow of gas to create an asymmetric flow of gas at the nasal airway of the patient throughout the respiratory cycle of the patient.

In some constructions, the gas inlet is inclined towards the first outlet.

In some constructions, the connector or elbow includes or is a flow guide.

In some constructions, the interface body is a nasal cushion.

In some configurations, the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface is configured to provide a greater dynamic pressure at the first nostril of the patient in use and a lesser dynamic pressure at the second nostril of the patient in use to create an asymmetric gas flow at the nasal airway of the patient throughout the respiratory cycle of the patient.

In some constructions, the nasal interface includes a flow guide configured to direct more of the incoming gas from the gas inlet to the first outlet than to the second outlet.

In some configurations, the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface comprises a flow splitter to split the flow from the gas inlet unequally into a first flow configured to be provided substantially to the first nasal delivery element and a second flow configured to be provided substantially to the second nasal delivery element, wherein the first flow is configured to deliver more flow along the first flow than along the second flow to create an asymmetric flow at the nasal airway of the patient throughout the respiratory cycle of the patient.

In some constructions, the gas inlet is inclined towards the first outlet.

In some constructions, the shunt portion is substantially rigid.

In some constructions, the interface body is a nasal cushion.

In some constructions, the nasal interface includes a bias flow restrictor comprising at least one aperture for flowing gas from the nasal interface to the ambient environment.

In some configurations, the nasal interface is configured such that the pressure differential of the gas flowing through the first outlet or first outlet portion and the second outlet or second outlet portion is higher during the exhalation phase than during the inhalation phase.

In some configurations, the pressure drop across the gas flow path is such that when there is a flow of gas from the gas inlet to the first nasal delivery element and the second nasal delivery element, the flow of gas from the gas inlet to the first nasal delivery element is greater than the flow of gas from the gas inlet to the second nasal delivery element.

In some constructions, the respiratory catheter has an inner diameter of between about 12mm and about 23mm, optionally greater than about 12mm and up to about 23mm, optionally greater than 12mm and up to about 22mm, optionally greater than about 12mm and up to about 21mm, optionally greater than about 12mm and up to about 20mm, optionally greater than about 12mm and up to about 19mm, optionally greater than about 12mm and up to about 18mm, optionally between about 13mm and about 17mm, optionally between about 14mm and about 16mm, optionally about 12mm, optionally about 13mm, optionally about 14mm, optionally about 15mm, optionally about 16mm, optionally about 17mm, optionally about 18mm, optionally about 19mm, optionally about 20mm, optionally about 21mm, optionally about 22mm, optionally about 23mm, or optionally any two of these values.

In some configurations, when gas is delivered from the gas inlet to the first nasal delivery element and the second nasal delivery element, the gas flow pressure at the second nasal delivery element is up to about 1cmH ₂ O lower than the gas flow pressure at the first nasal delivery element.

In some configurations, the at least one gas flow restrictor comprises a bypass flow restrictor to provide a pressure drop between the first and second nasal delivery elements through the gas flow path as gas is delivered from the gas inlet to the first and second nasal delivery elements such that the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element.

In some configurations, the inner cross-sectional areas of the first and second nasal delivery elements are at a minimum lateral dimension of the respective nasal delivery elements.

In some configurations, the internal cross-sectional areas of the first and second nasal delivery elements are at the outlet of the respective nasal delivery elements.

In some constructions, the gas inlet is on one side of the gas manifold.

an interface body, comprising: a first nasal delivery element including a first outlet configured to deliver gas to a first nostril of a patient, and a second nasal delivery element including a second outlet configured to deliver gas to a second nostril of the patient; and a gas inlet for delivering respiratory gas into the nasal interface, the interface body comprising a first interface body side arm and a second interface body side arm,

A frame comprising a first frame side arm and a second frame side arm,

Wherein the first and second interface body side arms each include a through-channel to enable a respective one of the first and second frame side arms to extend through the through-channel to couple the first and second frame side arms with the first and second interface body side arms, wherein when the first and second frame side arms are coupled with the first and second interface body side arms, a proximal portion of the first and second interface body side arms is positioned behind a proximal portion of the first and second frame side arms for positioning between a patient's face and the proximal portions of the first and second frame side arms in use.

In some constructions, each through passage includes a hole or slit.

In some constructions, the first and second frame side arms are configured to attach to the headgear.

In some constructions, the first and second frame side arms include headgear attachment features adjacent outer ends of the first and second frame side arms.

In some constructions, the interface body includes a central interface body portion, and wherein the frame includes a central frame body portion, wherein the central interface body portion and the central frame body portion are configured to be coupled together to define a gas flow path for delivering respiratory gases from the gas inlet through the first and second nasal delivery elements.

In some constructions, the central frame body portion includes a gas inlet.

In some configurations, the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient.

an interface body comprising a cushion and configured to substantially form a seal with a patient's nasal airway, the interface body configured to deliver gas to a patient's first naris and to a patient's second naris,

A frame configured to engage with the interface body,

Wherein the interface body comprises a softer material than the frame comprising a more rigid material,

And wherein the interface body and the frame are configured such that one or more bias flow vents are formed between the interface body and the frame when the interface body and the frame are engaged with each other.

In some constructions, the interface body includes a portion of the bias flow vent.

In some constructions, the frame includes a portion of the bias flow vent.

In some constructions, the interface body includes a first portion of the bias flow vent and the frame includes a second portion of the bias flow vent.

In some constructions, the portion of the bias flow drain includes a flow passage.

In some constructions, the nasal interface includes a plurality of bias flow vents.

In some constructions, the bias flow discharge openings are arranged in at least one array around a portion of the nasal interface.

In some configurations, the at least one array is configured to direct gas from the nasal interface in a divergent pattern.

In some configurations, the divergent mode includes an airflow that is at least partially laterally outward from the interface body and/or from the frame.

In some configurations, the divergent mode includes an airflow at least partially upward and/or downward from the interface body and/or from the frame.

In some constructions, the divergent mode is at least substantially conical.

In some constructions, the interface body comprises a central interface body portion, and wherein the frame comprises a central frame body portion, wherein the central interface body portion and the central frame body portion are configured to engage one another to define a gas flow path for delivering, in use, breathing gas from the gas inlet through the interface body to the first nostril of the patient and to the second nostril of the patient.

In some constructions, the central frame body portion includes a gas inlet.

In some configurations, the gas inlet is provided at or near one side of the central frame body portion, and wherein at least one of the one or more bias flow vents is provided at or near the other side of the central frame body portion between the interface body and the frame.

In some configurations, the nasal interface includes a single outlet for delivering gas to the first nostril and the second nostril of the patient.

In some configurations, the interface body includes a first nasal delivery element having a first outlet and a second nasal delivery element having a second outlet, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient.

An interface body including a first nasal delivery element configured to seal with a first nostril of a patient and a second nasal delivery element configured to seal with a second nostril of the patient,

A gas inlet for delivering respiratory gas into the nasal interface, wherein the gas inlet is positioned closer to the first nasal delivery element than to the second nasal delivery element,

And a bias flow discharge for flowing the airflow out of the nasal interface, wherein the bias flow discharge is positioned closer to the second nasal delivery element than the first nasal delivery element, and wherein the bias flow discharge comprises one or more elongated bias flow holes.

In some configurations, the nasal interface includes a gas flow passage in the nasal interface, and wherein at least one of the one or more elongated deflection holes extends from a position proximate to the gas inlet to a position at or proximate to the gas flow passage end.

In some configurations, an end of the at least one of the one or more elongated deflection holes is proximate to a periphery of an outlet of the gas inlet.

In some constructions, the nasal interface includes an interface body and a frame, wherein the interface body includes a first nasal delivery element and a second nasal delivery element, wherein the frame includes a bias flow vent.

In some constructions, the frame includes a recess, and wherein the bias flow vent is located in the recess.

In some constructions, the recess has an irregular shape.

In some constructions, the recess has an irregular polygonal shape.

In some constructions, the at least one flow deflecting aperture has one dimension that is greater than another dimension.

In some constructions, the bias flow discharge includes a plurality of elongated bias flow holes.

In some constructions, the plurality of elongated offset holes are arranged substantially parallel to one another.

In some constructions, the bias flow discharge includes a diffuser to diffuse gas flowing through the one or more elongated bias flow holes.

In some configurations, the gas inlet and the first and second nasal delivery elements are in fluid communication with the gas flow passage of the interface body to deliver breathing gas from the gas inlet through the first and second nasal delivery elements.

In some constructions, the one or more elongated deflection holes are elongated in a direction extending across the nasal interface.

A gas inlet for delivering breathing gas into the nasal interface,

A bias flow vent for airflow out of the nasal interface,

Wherein the inner surface of the gas inlet transitions to the inner surface of the nasal interface at the outlet, wherein the outlet comprises a perimeter having a plurality of portions of different radii from one another, wherein the radius of the portion of the perimeter proximate the bias flow discharge port is greater than the radius of the other portions of the perimeter.

In some configurations, the gas inlet is positioned closer to the first nasal delivery element than the second nasal delivery element.

In some configurations, the bias flow discharge port is positioned closer to the second nasal delivery element than the first nasal delivery element.

In some constructions, the outlet has a non-circular cross-sectional shape.

In some constructions, the bias flow vent includes one or more elongated bias flow holes.

And a bias flow discharge for flowing the air flow out of the nasal interface, the bias flow discharge being positioned closer to the second nasal delivery element than the first nasal delivery element,

Wherein the inner surface of the interface body comprises a protrusion extending from the base of the first nasal delivery element towards the gas inlet, the protrusion extending radially outwards as it extends towards the gas inlet.

In some constructions, the protrusion includes a ring surrounding the base of the first nasal delivery element.

In some configurations, the protrusion defines a protrusion gas flow channel, and wherein the protrusion gas flow channel has a larger cross-sectional area at a distal region closer to the gas inlet than at a region closer to the first nasal delivery element.

In some configurations, the protrusions form a funnel to direct the gas flow from the gas inlet into the first nasal delivery element.

In some constructions, the protrusion is integral with the interface body.

In some constructions, the protrusion includes a plurality of protrusions.

an interface body including a first nasal delivery element configured to seal with a first naris of a patient, a second nasal delivery element configured to seal with a second naris of the patient, a first gas flow path in fluid communication with the first nasal delivery element, a second gas flow path in fluid communication with the second nasal delivery element, and a wall configured to pneumatically isolate the first gas flow path and the second gas flow path within the interface body,

A gas inlet for delivering breathing gas to the first gas flow passage,

And a bias flow vent for flowing a flow of gas out of the nasal interface, wherein the bias flow vent is in fluid communication with the second gas flow path.

In some configurations, the gas inlet is configured to direct a flow of breathing gas from the gas inlet to the outlet of the first nasal delivery element.

In some configurations, at least the outlet of the gas inlet is arranged to direct the flow of breathing gas to the outlet of the first nasal delivery element.

In some configurations, the nasal interface comprises an interface body and a frame, wherein the interface body comprises a first nasal delivery element and a second nasal delivery element, wherein the wall is provided by the frame, or by the interface body, or by the frame and the interface body.

In some constructions, the nasal interface includes an insert for positioning in or within the interface body, wherein the insert includes a wall.

In some constructions, the insert includes two wings projecting laterally outward from the wall in opposite directions from each other.

In some constructions, the wings project laterally outward from the rear of the wall in opposite directions from each other.

In some configurations, the wings are configured to contact an interface body inner surface proximate to the base of the first and second nasal delivery elements.

In some constructions, each wing includes a ring member having a size at least equal to or greater than the base of the first and second nasal delivery elements.

In some constructions, the wings are configured to form a seal against the interface body inner surface.

In some constructions, the insert, the interface body, and/or the frame of the nasal interface include one or more engagement features for engaging the insert in the nasal interface.

In some constructions, the nasal interface is configured such that, in use, biasing the discharge port creates a pressure in the second gas flow passage so as to minimize a pressure differential between the pressures created in the first and second gas flow passages.

In some constructions, the wall is configured to cause unidirectional airflow during use.

In some constructions, the wall is configured to cause unidirectional airflow during a phase of a patient's respiratory cycle.

In some constructions, the wall includes a shape corresponding to a cross-sectional shape of the first gas flow channel, the second gas flow channel, or both the first gas flow channel and the second gas flow channel.

In some constructions, the wall has the same rigidity as the interface body or has a different rigidity than the interface body.

In some constructions, the wall comprises the same material as the interface body or comprises a different material than the interface body.

In some constructions, the nasal interface includes an interface body and a frame, and wherein the wall has the same rigidity as the frame or has a different rigidity than the frame.

In accordance with certain features, aspects, and advantages of at least one embodiment disclosed herein, a respiratory therapy system is disclosed, comprising:

a gas source for a breathing gas configured to provide a pressure controlled breathing gas;

A breathing tube for receiving a pressure-controlled breathing gas; and

A nasal interface, as described above or herein, is in fluid communication with a breathing tube to deliver breathing gas to a patient.

In some configurations, the interface body includes a first outlet or first outlet portion configured to deliver gas to a first naris of the patient and includes a second outlet or second outlet portion configured to deliver gas to a second naris of the patient, and wherein the nasal interface is configured to generate a pressure differential between the first outlet or first outlet portion and the second outlet or second outlet portion when gas is delivered from the gas inlet to both the first outlet or first outlet portion and the second outlet or second outlet portion such that a pressure at the first outlet or first outlet portion is higher than a pressure at the second outlet or second outlet portion.

A breathing tube for receiving a pressure-controlled breathing gas; and

A nasal interface having a gas inlet in fluid communication with the breathing tube to deliver breathing gas to a patient, the nasal interface comprising a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the nasal interface is configured to create a pressure differential between the first nasal delivery element and the second nasal delivery element when gas is delivered from the gas inlet to both the first nasal delivery element and the second nasal delivery element such that a pressure at the first nasal delivery element is higher than a pressure at the second nasal delivery element.

In some configurations, the respiratory therapy system includes a breathing conduit to receive a pressure-controlled breathing gas from the breathing tube, wherein the breathing conduit is in fluid communication with the breathing tube and a gas inlet of the nasal interface.

In some constructions, the respiratory therapy system further includes a respiratory gas filter.

In some constructions, the breathing gas filter is located between the breathing tube and the breathing conduit.

In some constructions, the respiratory gas filter is located between the gas manifold and the bias flow restrictor.

In some configurations, the respiratory therapy system further includes a humidifier configured to humidify the pressure-controlled respiratory gas prior to delivery to the nasal interface.

In some constructions, the breathing tube is a heated breathing tube and is configured to receive pressure-controlled breathing gas from the humidifier.

In some configurations, the temperature of the air stream exiting the first and second nasal delivery elements is between about 31 ℃ and about 41 ℃, optionally greater than 31 ℃ and up to about 41 ℃, optionally between about 36 ℃ and about 39 ℃, optionally about 37 ℃.

According to certain features, aspects, and advantages of at least one embodiment disclosed herein, there is provided a method of providing respiratory support to a patient, the method comprising:

providing a respiratory therapy system, the respiratory therapy system comprising:

A breathing tube for receiving a pressure-controlled breathing gas; and

A nasal interface having a gas inlet in fluid communication with the breathing tube to deliver breathing gas to a patient, the nasal interface comprising a first nasal delivery element and a second nasal delivery element;

Sealing each of the first nasal delivery element and the second nasal delivery element with a respective nostril of the patient;

Operating the respiratory therapy apparatus to provide an airflow to the nasal interface; and

An asymmetric airflow is delivered from the respiratory therapy apparatus through the first nasal delivery element and the second nasal delivery element at the nostrils of the patient.

In some configurations, the nasal delivery elements are in fluid communication with the gas inlet via a gas flow path, wherein the first nasal delivery element is proximal to the gas inlet and the second nasal delivery element is distal to the gas inlet, and wherein the nasal interface comprises a bypass restrictor providing a cross-sectional area of a portion of the gas flow path, wherein the first nasal delivery element and the second nasal delivery element each comprise an internal cross-sectional area, wherein the internal cross-sectional areas together provide a combined cross-sectional area of the first nasal delivery element and the second nasal delivery element, and wherein the cross-sectional area of the portion of the gas flow path is greater than 0 to about 1.5 times the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element.

In some configurations, the cross-sectional area of the portion of the gas flow passage is up to about 1 times, optionally up to about 2/3 times, the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element, and wherein the method comprises providing a pressure of 4cmH ₂ O to the gas inlet such that there is a bias flow of 20lpm through the bias flow restrictor.

In some configurations, the cross-sectional area of the portion of the gas flow passage is up to about 1 times, optionally up to about 2/3 times, the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element, and wherein the method comprises providing a pressure of 8cmH ₂ O to the gas inlet such that there is a bias flow of 32lpm through the bias flow restrictor.

In some constructions, the cross-sectional area of the portion of the gas flow path is up to about 2/3 times the combined cross-sectional area of the first and second nasal delivery elements, and wherein the method comprises providing a pressure of 4cmH ₂ O to the gas inlet such that there is a bias flow through the bias flow restrictor, or wherein the method comprises providing a pressure of 8cmH ₂ O to the gas inlet such that there is a bias flow of 32lpm through the bias flow restrictor, or wherein the method comprises providing a pressure of 12cmH ₂ O to the gas inlet such that there is a bias flow of 41lpm through the bias flow restrictor, or wherein the method comprises providing a pressure of 16cmH ₂ O to the gas inlet such that there is a bias flow of 48lpm through the bias flow restrictor, or wherein the method comprises providing a pressure of 20cmH ₂ O to the gas inlet such that there is a bias flow of 53lpm through the bias flow restrictor.

In some configurations, the cross-sectional area of the portion of the gas flow passage is up to about 2/3 times the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element, and wherein the method comprises providing a pressure of 8cmH ₂ O to the gas inlet such that there is a bias flow of 32lpm or more through the bias flow restrictor.

In some constructions, the cross-sectional area of the portion of the gas flow path is up to about 1/3 times the combined cross-sectional area of the first and second nasal delivery elements, and wherein the method comprises providing a pressure of 8cmH ₂ O to the gas inlet such that there is a bias flow through the bias flow restrictor, or wherein the cross-sectional area of the portion of the gas flow path is up to about 2/5 times the combined cross-sectional area of the first and second nasal delivery elements, and wherein the method comprises providing a pressure of 12cm H ₂ O to the gas inlet such that there is a bias flow through the bias flow restrictor of 41lpm or more, or wherein the cross-sectional area of the portion of the gas flow path is up to about 2/3 times the combined cross-sectional area of the first and second nasal delivery elements, and wherein the method comprises providing a pressure of 16cm H ₂ O to the gas inlet such that there is a bias flow through the bias flow restrictor of 48lpm or more.

In some constructions, the nasal interface is as described above or herein.

In some constructions, the respiratory therapy system is as described above or herein.

A breathing tube for receiving a pressure-controlled breathing gas; and

A nasal interface in fluid communication with the breathing tube 16 to deliver breathing gas to a patient;

sealing the nasal interface with the patient's nasal airway;

An ingress gas is received at a gas inlet of the nasal interface and an asymmetric gas flow is generated at the patient's nasal airway.

In some configurations, the method includes generating an asymmetric flow of gas at the patient's nasal airway throughout the patient's respiratory cycle.

In some constructions, the nasal interface is as described above or herein.

Features from one or more embodiments or configurations may be combined with features of one or more other embodiments or configurations. In addition, more than one embodiment or configuration may be used together in a respiratory support system during a respiratory support procedure for a patient.

As used herein, the term "one or more" refers to the plural and/or singular forms of nouns.

As used herein, the term "and/or" means "and" or both, where the context permits.

The term "comprising" as used in this specification means "consisting at least in part of …". When interpreting each statement in this specification that includes the term "comprising," features other than that or those prefixed by that term may also be present. Related terms such as "comprising" and "including" will be interpreted in the same manner.

The recitation of numerical ranges herein (e.g., 1 to 10) is intended to include all logical ranges within that range (e.g., 1, 1.1, 2,3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10) as well as any logical ranges within that range (e.g., 2 to 8, 1.5 to 5.5, and 3.1 to 4.7), and therefore all sub-ranges of all ranges explicitly disclosed herein are also expressly recited herein. These are merely examples of specific intent and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this disclosure in a similar manner.

The disclosure may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of the parts, elements or features.

When reference is made herein to a specific entity having known equivalents in the field to which this disclosure relates, such known equivalents should be considered as if individually set forth.

The present disclosure includes the foregoing, and also contemplates configurations that are given below only as examples.

Drawings

Specific embodiments and variations thereof will be apparent to those skilled in the art from the detailed description herein with reference to the following drawings, in which:

fig. 1 is a front perspective view of an exemplary constructed patient interface of the present disclosure including a nasal interface.

Fig. 2 is a close-up perspective view of the nasal interface.

Fig. 3 is a rear perspective view of the patient interface.

Fig. 4 is a close-up perspective view of the nasal interface.

Fig. 5 is a front perspective view of the patient interface showing the gas manifold component separate from the interface body component including the nasal delivery element, the bias flow restriction component separate from the gas manifold component, and the respiratory conduit separate from the gas manifold component.

Fig. 6 (a) is a front perspective view of the bias current flow block.

Fig. 6 (b) is an exploded front perspective view of the components of the bias current flow restrictor.

Fig. 7 (a) is a perspective cutaway view of the bias current flow restrictor.

Fig. 7 (b) is a front projection cross-sectional view of the bias current flow restriction member.

Fig. 8 is an orthographic view of the front of the bias current restrictor.

Fig. 9 is a front partial cross-sectional view of the nasal interface showing a gas flow restriction in the gas manifold.

Fig. 10 (a) is a front perspective cutaway view of the nasal interface, schematically illustrating the direction of airflow through the nasal interface.

Fig. 10 (b) is a front cross-sectional view of the nose interface, schematically illustrating the direction of airflow through the nose interface.

Fig. 11 shows a view of a gas manifold, wherein fig. 11 (a) is a front perspective view, fig. 11 (b) is a front perspective view taken through a horizontal plane, and fig. 11 (c) is a front perspective view taken through a vertical plane.

Fig. 12 shows a view of a gas manifold, where fig. 12 (a) is a top view, fig. 12 (b) is a cross-sectional view along a line b-b of fig. 12 (d), fig. 12 (c) is a front view, fig. 12 (d) is an end view, and fig. 12 (e) is a cross-sectional view along a line e-e of fig. 12 (d).

Fig. 13 shows a view of the face-mount or interface body component of the nasal interface, wherein fig. 13 (a) is a rear view, fig. 13 (b) is a front view, and fig. 13 (c) is a cross-sectional view taken along line c-c of fig. 13 (b).

Fig. 14 is a cross-sectional view through the gas manifold and one of the nasal delivery elements.

Fig. 15 is a schematic diagram of the functions and effects of using a patient interface.

Fig. 16 shows a side exchange function in which the breathing conduit is coupled to the right side of the gas manifold in fig. 16 (a) and the breathing conduit is coupled to the left side of the gas manifold in fig. 16 (b).

Fig. 17 (a) shows the remote positioning of the bias current flow restriction member.

Fig. 17 (b) shows the remote location of the flow diverter with a filter between the gas manifold and the flow diverter.

Fig. 18 is an exploded view of the components of the headgear of the patient interface.

Fig. 19 schematically illustrates the construction of the nasal interface of fig. 1-18.

Fig. 20 schematically illustrates an alternative configuration of the nasal interface.

Fig. 21 schematically illustrates another alternative configuration of the nasal interface.

Fig. 22 illustrates a respiratory therapy system including a patient interface and nasal interface of the present disclosure.

FIG. 23 shows pressures at 4cmH ₂ O and 8cmH ₂ O for 15 breaths per minute 10i:20e 500vt (tidal volume) breathing pattern, results of testing different ratios of bypass restrictor to combined nasal delivery element area.

FIG. 24 shows the results of testing the different ratios of bypass restrictor to combined nasal delivery element area for 25 breaths/min ARDS (acute respiratory distress syndrome) breathing patterns at pressures of 4cmH ₂O、8cmH₂O、12cmH₂O、16cmH₂ O and 20cmH ₂ O.

FIG. 25 shows the results of testing the different ratios of bypass restrictor to combined nasal delivery element area for a 45 breaths per minute 350Vt (tidal volume) sinusoidal breathing pattern at pressures of 4cmH ₂O、8cmH₂O、12cmH₂O、16cmH₂ O and 20cmH ₂ O.

Figure 26 shows the simulated effect of different nasal delivery element sizes, different bypass restrictor cross-sectional areas, different set pressures and different bias flow restrictor openings for 15 breaths per minute upon re-inhalation with the nasal interface.

Figure 27 shows the simulated effect of different nasal delivery element sizes, different bypass restrictor cross-sectional areas, different set pressures and different bias flow restrictor openings for 25 breaths per minute upon re-inhalation with the nasal interface.

Figure 28 shows the simulated effect of different nasal delivery element sizes, different bypass restrictor cross-sectional areas, different set pressures and different bias flow restrictor openings for 45 breaths per minute upon re-inhalation with the nasal interface.

Fig. 29 schematically illustrates an alternative configuration nasal interface for use in a patient interface.

Fig. 30 shows a front perspective view of an exemplary configuration of a nasal interface.

Fig. 31 shows a front cross-sectional view of the nasal interface, showing the gas flow path.

Fig. 32 shows a front cross-sectional view of the nasal interface, showing the exhaust flow path.

Fig. 33 shows a top partial cross-sectional view of the nasal interface.

Fig. 34 shows another top partial cross-sectional view of the nasal interface.

Fig. 35 shows a front perspective view of the interface body/nose pad of the nasal interface.

Fig. 36 shows a front elevation view of the interface body/nose pad of the nasal interface.

Fig. 37 shows a front cross-sectional view of an alternative exemplary configuration nasal interface.

Fig. 38 shows a front perspective cutaway view of another alternative exemplary configuration nasal interface.

Fig. 39 shows a front perspective view of another alternative exemplary configuration nasal interface.

Fig. 40 shows a partial cross-sectional view of the nasal interface.

Fig. 41 shows a front perspective cutaway view of an alternative exemplary configuration nasal interface.

Fig. 42 shows a front perspective cutaway view of an alternative exemplary configuration nasal interface.

Fig. 43 shows a top view of an alternative exemplary configuration nasal interface.

Fig. 44 shows a front cross-sectional view of an alternative exemplary configuration nasal interface, wherein fig. 44 (a) shows the nasal cushion in a resting state and fig. 44 (b) shows the nasal cushion in a compressed state.

Fig. 45 shows a front perspective view of an alternative exemplary configuration nose pad for use in a nasal interface.

Fig. 46 shows a rear perspective view of the nose pad.

Fig. 47 illustrates the deformation or movement of the flow directing or diverting portion of the nasal cushion.

Fig. 48 illustrates an alternative deformation or movement of the flow directing or diverting portion of the nasal cushion.

Fig. 49 shows an alternative exemplary configuration nose pad for use in a nasal interface, wherein fig. 49 (a) is a first front perspective view and fig. 49 (b) is a second front perspective view.

Fig. 50 (a) - (c) show three alternative exemplary configurations of nasal cushions for use in nasal interfaces.

Fig. 51 shows an alternative exemplary configuration nose pad for use in a nasal interface, wherein fig. 51 (a) is a top perspective view and fig. 51 (b) is a front view.

Fig. 52 shows an alternative exemplary configuration nose pad for use in a nasal interface, wherein fig. 52 (a) is a rear view and fig. 52 (b) is a top perspective view.

Fig. 53 is a front perspective view of an alternative exemplary configuration nasal interface.

Fig. 54 is an exploded front perspective view of the nasal interface.

Fig. 55 is an exploded rear perspective view of the nasal interface.

Fig. 56 is a top cross-sectional view of the nasal interface.

Fig. 57 is a front perspective view of a patient interface including an alternative exemplary configuration nasal interface.

Fig. 58 is a top cross-sectional view of the nasal interface.

Fig. 59 is a front perspective view of a nose pad of a nasal interface.

Fig. 60 is a front perspective view of an alternative example configuration patient interface including an alternative example configuration nasal interface.

Fig. 61 is a front perspective view of the nasal interface.

Fig. 62 is a front perspective view of the interface body of the nasal interface.

Fig. 63 is a front perspective view of the frame of the nasal interface.

Fig. 64 is a front perspective view of a headgear of the patient interface.

Fig. 65 is a front perspective view of the interface body of the nasal interface.

Fig. 66 is a rear perspective view of the interface body of the nasal interface.

Fig. 67 is a top cross-sectional view of one of the side arms of the interface body, showing one of the side arms of the frame.

Fig. 68 is a top cross-sectional view of one of the side arms of the interface body.

Fig. 69 is a cross-sectional view of the interface body.

Fig. 70 is a cross-sectional view of a nasal interface showing one configuration of a nasal delivery element.

Fig. 71 is a top cross-sectional view of the nasal interface.

Fig. 72 is a cross-sectional view of the nasal interface, showing one nasal delivery element.

Fig. 73 is a top cross-sectional view of a nasal interface showing an alternative configuration of a nasal delivery element.

Fig. 74 shows a cross-sectional view of one of the nasal delivery elements of the nasal interface of fig. 73.

Fig. 75 is a top cross-sectional view of the nasal interface, showing one configuration of the gas inlet.

Fig. 76 is a side cross-sectional view of the nasal interface.

Fig. 77 is a top cross-sectional view showing more details of the construction of the gas inlet.

Fig. 78 is a top cross-sectional view showing an alternative configuration of the gas inlet.

Fig. 79 is a front perspective view of the nasal interface showing the bias flow discharge.

Fig. 80 is a side view of the nasal interface.

Fig. 81 is a rear view of the interface body of the nasal interface.

Fig. 82 is an enlarged top view of the nasal interface showing the bias flow discharge.

Fig. 83 is a cross-sectional view of the nasal interface, showing the bias flow path.

Fig. 84 is an enlarged cross-sectional view showing one of the bias current paths.

Fig. 85 shows an exemplary configuration of a nozzle for use in a nasal interface.

Fig. 86 is a front perspective view of an alternative example configuration patient interface including an alternative example configuration nasal interface.

Fig. 87 is another front perspective view of the patient interface of fig. 86.

Fig. 88 is an exploded front perspective view of the patient interface of fig. 86.

Fig. 89 is a front view of the nasal interface of fig. 86.

Fig. 90 is a front perspective view of the nasal interface of fig. 86.

Fig. 91 is another front perspective view of the nasal interface of fig. 86.

Fig. 92 is another front perspective view of the nasal interface of fig. 86.

Fig. 93 is a front perspective view of the interface body of the nasal interface of fig. 86.

Fig. 94 is a side cross-sectional view of the nasal interface of fig. 86.

Fig. 95 is a front view of the nasal interface of fig. 86.

Fig. 96 is a front view of the frame of the nasal interface of fig. 86.

Fig. 97 is a rear view of the frame of fig. 96.

Fig. 98 is a front perspective view of the nasal interface of fig. 86.

Fig. 99 is a top cross-sectional view of the nasal interface of fig. 98, showing the gas flow path in the nasal interface body.

Fig. 100 is a top cross-sectional view through the frame of the nasal interface of fig. 98.

FIG. 101 is a graph showing the relationship between bias flow (lpm) and patient pressure (cmH ₂ O).

Fig. 102 (a) shows the "fanout" area of the low aspect ratio aperture for the bias flow discharge and fig. 102 (b) shows the "fanout" area of the high aspect ratio elongated aperture for the bias flow discharge.

Fig. 103 is a front perspective view of an alternative configuration nasal interface for use in the patient interface of fig. 86, having a higher aspect ratio aperture for biasing the discharge orifice as compared to fig. 95.

Fig. 104 is a front perspective view of an alternative construct frame for use in the alternative construct nasal interface of fig. 86, the frame interface having a lower aspect ratio non-aperture for a bias flow vent, for example, as compared to fig. 95, and a lower aspect ratio for a bias flow vent, as compared to fig. 103.

Fig. 105 is a rear perspective view of the frame of fig. 104.

Fig. 106 is a top cross-sectional view of an interface body of an alternative construction nasal interface, the interface body including a protrusion extending from a base of the first nasal delivery element toward the gas inlet.

Fig. 107 is a top cross-sectional view of the interface body and frame of fig. 106, showing the direction of gas flow from the gas inlet of the nasal interface.

Fig. 108 is a front cross-sectional view of the interface body of fig. 106, showing two protrusions.

FIG. 109 is a front perspective view of an interface body of an alternative construction of a nasal interface including a wall configured to pneumatically isolate a first gas flow path and a second gas flow path within the interface body;

FIG. 110 is a cut-away perspective view showing a nasal interface with the wall of FIG. 109;

Fig. 111 is a front perspective view showing an insert for an interface body, which may provide a wall.

Fig. 112 is a cutaway perspective view showing a nasal interface with a wall provided by a portion of the frame.

Fig. 113 is another cutaway perspective view showing a nasal interface with a wall provided by a portion of the frame.

Fig. 114 is a rear perspective view of the frame of the nasal interface of fig. 112.

Fig. 115 is another rear perspective view of the frame of fig. 114.

FIG. 116 is a front perspective view of an alternate interface body that constructs a nasal interface including a wall having a flow passage that provides a bypass restrictor for the gas flow passage of the nasal interface.

FIG. 117 is a cutaway perspective view showing a nasal interface with the wall and flow passage of FIG. 116;

Fig. 118 is a front perspective view showing an insert for an interface body that may provide walls and flow channels.

Fig. 119 is a rear perspective view of the nasal interface of the patient interface of fig. 96.

Fig. 120 is a first front perspective view of a headgear for use in a nasal interface.

Fig. 121 is a second front perspective view of the headgear of fig. 120.

Fig. 122 is a front perspective view of a frame of a nasal interface with a plurality of elongated deflection holes.

Detailed Description

The patient interface may be used to deliver breathing gas to the airway of a patient. The patient interface may include a nasal interface that may be used to deliver an airflow to a patient. In some configurations, a nasal delivery element, such as a nasal prong or pillow, is inserted into the patient's nose to deliver the desired treatment. The nasal delivery element may be desirably sealed at the nose to deliver the treatment. The one or more nasal delivery elements may include a nasal pillow to seal at the nose.

A system for delivering gas to a patient through a nasal interface is disclosed.

The system provides a pressure differential at the first and second nasal delivery elements of the nasal interface, thereby creating differential airflow at the first and second nasal delivery elements. This allows for asymmetric airflow to be delivered to both nostrils through the nasal interface. Asymmetric airflow as described herein refers to different airflows within the nasal interface or within the nose. In this way, a different airflow may be delivered by each nasal delivery element. The asymmetric gas flow may also include a partial unidirectional gas flow.

Delivering an asymmetric airflow may improve the clearance of dead spaces in the upper airway. The nasal interface is configured to create such asymmetric airflow through the nasal delivery element.

The airflow generated by respiratory therapy depends on the airflow through the nasal interface, which depends on the pressure at each nasal delivery element. If the pressure at each nasal delivery element is different, an asymmetric airflow will be created.

If the flow of air, leakage, or a combination of flow and leakage through the nasal interface is asymmetric, the flow of air through the nose may become asymmetric during breathing. The partial unidirectional air flow may be an asymmetric air flow. As air is flushed out of the upper airway, a portion of the unidirectional airflow may provide improved clearance of anatomical dead spaces. Part of the unidirectional airflow may be more comfortable than the total unidirectional airflow. The total unidirectional airflow herein includes all airflow that enters one naris through the nasal delivery element and exits the other naris through the nasal delivery element, all airflow that is vented to the atmosphere due to the absence of the nasal delivery element, and so forth. The partial unidirectional airflows described herein include airflows that may enter the nose via both nostrils and exit the nose from one nostril, airflows that may enter the nose via both nostrils and exit the nose via both nostrils, airflows that may enter different proportions of the nose via both nostrils, and/or airflows that may exit different proportions of the nose via both nostrils, and airflows that may enter the nose via both nostrils and exit the nose from one or both nostrils and optionally via the mouth. If there is a pressure differential between the first nasal delivery element and the second nasal delivery element, the first nasal delivery element will receive more gas flow from the gas inlet during inhalation than the second nasal delivery element. During exhalation, the second nostril associated with the second nasal delivery element will exhaust more airflow than the first nostril associated with the first nasal delivery element. The pressure differential between the first nasal delivery element and the second nasal delivery element may vary depending on whether the patient's respiratory cycle is in the inspiratory phase or the expiratory phase.

Asymmetric airflow assessment may be applied over a suitable period of time. For example, the asymmetric airflow assessment may be applied over one respiratory cycle of the patient or alternatively over a different number of respiratory cycles of the patient.

Part of the unidirectional airflow may reduce turbulence in the nasal cavity of the patient, which may improve comfort.

Fig. 1-5 illustrate an exemplary patient interface 1 that includes a nasal interface 100 having nasal delivery elements including a first nasal delivery element 111 and a second nasal delivery element 112.

The nasal interface 100 provides a patient interface for a patient that is adapted to deliver a controlled pressure, optionally high humidity, airflow to the nasal cavity/nostrils of the patient. In some configurations, the nasal interface 100 is adapted to deliver high flow rates of gas over a wide flow range (e.g., about 8lpm, or higher depending on other therapeutic applications, possibly, for example, 10-50lpm, 20-40lpm, or higher). The flow may be a bias flow averaged over time. In some constructions, the nasal interface 100 is adapted to deliver a lower flow of gas. The flow rate is dependent on the pressure, and therefore the flow rate fluctuates according to different respiratory pressures and set pressures. Wherein the set pressure relates to a therapy and/or patient pressure maintained by the assisted respiratory therapy device when used in conjunction with the nasal interface of the present disclosure.

The nasal interface 100 includes a facial mount component or interface body 110 component that includes a pair of hollow nasal delivery elements 111 and 112 integrally molded or removably attached to the interface body 110. The nasal interface 100 includes a gas manifold 120 component that includes a gas inlet 121. The gas manifold 120 may be removably attached or integrally molded to the respiratory conduit 300.

The interface body 110 component can be connectable or engageable to the gas manifold 120 component, or can be integrally formed with or permanently engaged with the gas manifold 120 component. If the interface body 110 component is engageable with the gas manifold component 120, the engagement places the first and second nasal delivery elements 111, 112 in fluid communication with the gas inlet 121 such that the first nasal delivery element 111 is closer to the gas inlet 121 and the second nasal delivery element 112 is farther from the gas inlet 121.

Interface body 110 may be formed of a soft, flexible material, such as silicone, thermoplastic elastomer, or other polymers known in the art. Nasal delivery elements 111 and 112 may be flexible and may be formed of a thin enough layer of silicone or other suitable material to achieve this characteristic. The interface body 110 and the nasal delivery elements 111, 112 may be formed, for example, of an elastomeric material capable of conforming to the geometry of the patient's nostrils and/or cheek and providing an effective pneumatic seal.

The gas manifold 120 may be formed of a relatively harder material, such as polycarbonate, high Density Polyethylene (HDPE), or any other suitable plastic material known in the art. Interface body 110 provides a soft interface member for the patient to comfortably deliver a flow of gas through nasal delivery elements 111 and 112, while gas manifold 120 fluidly couples respiratory catheter 300 to nasal delivery elements 111 and 112 of interface body 110.

The nasal delivery elements 111 and 112 are substantially hollow.

The first and second nasal delivery elements 111, 112 may have the same shape and configuration as each other, i.e., may be symmetrical. In other configurations, the first and second nasal delivery elements may have different shapes and/or configurations from one another, i.e., may be asymmetric.

The interface body 110 is shaped to generally follow the contours of the patient's face around the upper lip region. The interface body 110 is molded or preformed to be able to conform to the contours of the user's face in the facial region where the nasal interface will be located and/or to be pliable to accommodate, conform to, and/or correspond to the contours of the user's face.

Referring to fig. 13 (a) - (c), interface body 110 includes a base 118 from which nasal delivery elements 111 and 112 extend.

The base 118 is arranged in use to lie between the patient's face and the gas manifold 120. The base 118 may serve as a cushion to prevent the gas manifold 120 from contacting the patient's face.

In the illustrated construction, the interface body 110 includes two side arms extending laterally from either side of the base 118.

In the illustrated construction, the side arms include wings 113 and 114 extending laterally from either side of the base 118. Wings 113 and 114 are integrally formed with base 118, but may alternatively be separate components.

In some constructions, the nasal delivery elements 111, 112 extend generally upward and rearward from the base 118 of the interface body 110.

An adhesive pad (not shown) may be provided on each wing 113, 114 to facilitate coupling the nasal interface 100 to a patient.

The gas manifold 120 is generally tubular with gas ports 121, 122 on at least one side thereof and optionally on both sides (fig. 5, 11 and 12). At least one of the gas ports 121, 122 may be removably attached to the respiratory catheter 300, such as by threaded engagement, but alternatively by a snap fit or any other type of coupling known in the art. This enables at least one of the gas ports 121, 122 to be used as a gas inlet to the gas manifold 120 and thus to the nasal interface 100. Or ports 121, 122 may be fixedly coupled to or integrally formed with respiratory conduit 300.

By having the breathing conduit 300 extending from one side of the gas manifold 120 and thus from one side of the nasal interface 100, the patient's mouth is readily available when wearing the nasal interface for, for example, feeding/eating, drinking, or oral communication.

The gas flow enters the nasal interface 100 through the gas inlet and flows through the gas manifold 120 in a direction substantially transverse to the direction in which the gas flow is to enter the first and second nasal delivery elements 111, 112.

The gas inlet is in fluid communication with the breathing conduit 300.

In some constructions, the inner diameter of the respiratory catheter 300 is between about 12mm and about 23mm, alternatively greater than about 12mm and up to about 22mm, alternatively greater than about 12mm and up to about 21mm, alternatively greater than about 12mm and up to about 20mm, alternatively greater than about 12mm and up to about 19mm, alternatively greater than about 12mm and up to about 18mm, alternatively between about 13mm and about 17mm, alternatively between about 14mm and about 16mm, alternatively about 12mm, alternatively about 13mm, alternatively about 14mm, alternatively about 15mm, alternatively about 16mm, alternatively about 17mm, alternatively about 18mm, alternatively about 19mm, alternatively about 20mm, alternatively about 21mm, alternatively about 22mm, alternatively about 23mm, or alternatively any value between any two of these values.

Referring to fig. 11 and 12, the gas flow path is defined by lumens or flow channels 125 in the gas manifold 120.

The flow channels 125 extend through the gas manifold from the gas ports 121 on one side of the gas manifold 120 to the gas ports 122 on the other side of the gas manifold 120.

The flow passage 125 is in fluid communication with the first gas outlet 123 and the second gas outlet 124. The first gas outlet 123 is configured to deliver gas to the first nasal delivery element 111 and the second gas outlet 124 is configured to deliver gas to the second nasal delivery element 112.

The shape of the gas outlets 123, 124 corresponds to and mates with the interface body 110, such as by a friction fit or snap fit engagement, such that considerable force or at least intentional force applied by a user or caregiver is required to separate the manifold 120 from the interface body 110.

When the gas manifold 120 is engaged with the interface body 110, an effective seal is formed between the gas outlets 123, 124 and the interface body 110.

In the illustrated construction, each of the gas outlets is disposed in a respective outlet portion 123a, 124a of the gas manifold 120.

Each outlet portion 123a, 124a includes a sealing flange 123b, 124b for engagement with the first and second nasal delivery elements 111, 112.

Sealing flanges 123b, 124b extend laterally outwardly from adjacent portions of the respective outlet portions 123a, 123 b. The sealing flanges 123b, 124b are received in respective portions 111x, 112x of the nasal delivery elements 111, 112.

In the illustrated construction, the sealing flanges 123b, 124b are generally annular and the respective portions 111x, 112x of the nasal delivery elements include annular grooves in the inner surfaces of the nasal delivery elements 111, 112.

In alternative constructions, the sealing flanges 123b, 124b and the respective portions 111x, 112x may have different shapes. For example, they may each include one or more separate members that do not extend around the entire perimeter of the outlet portion 123a, 123b and the nasal delivery elements 111, 112.

In the illustrated construction, the outlet portions 123a, 124a and the sealing flanges 123b, 124b are received inside the nasal delivery elements 111, 112. In an alternative configuration, it may be reversed such that the base of the nasal delivery elements 111, 112 is received inside the body portions 123a, 124 a. In this configuration, the outlet portions 123a, 124a may include a sealing collar for engagement with the first and second nasal delivery elements. The sealing collar may engage with the exterior of the nasal delivery element to provide a seal therebetween.

The nasal delivery elements 111, 112 may comprise protrusions received in corresponding recesses of the sealing collar. The protrusions and recesses may be generally annular or may have a different configuration than the sealing flanges 123b, 124b and complementary portions 111x, 112x described above.

In some constructions, the sealing flange or collar and the complementary portion on the nasal delivery element also serve as a retention feature to retain the interface body 110 and the gas manifold 120 in engagement with one another. In alternative constructions, the interface body 110 and the gas manifold 120 may include one or more other retention features, such as clips or fasteners, etc., to retain the interface body 110 and the gas manifold 120 in engagement with one another.

The gas manifold 120 may be comprised of a single component or may include multiple components that are assembled together. For example, the gas manifold 120 may have a first body portion that provides a gas flow passage 125 and optionally gas ports 121, 122. The gas manifold 120 may have a second body portion providing gas outlets 123, 124. Or the gas manifold 120 may be a single component. In an alternative configuration, the gas manifold 120 may include a single outlet, and the interface body 110 may include a single complementary gas inlet coupled with the single outlet of the gas manifold 120 and in fluid communication with the first and second nasal delivery elements 111, 112 to deliver gas to the first and second nasal delivery elements 111, 112.

Referring to fig. 1-14 and 18, in some constructions, the nasal interface 100 of the present disclosure includes a first nasal delivery element 111 and a second nasal delivery element 112. The first nasal delivery element 111 and the second nasal delivery element 112 are each configured to seal with a respective nostril of the patient. The first nasal delivery element is configured to seal with a first nostril of a patient and the second nasal delivery element is configured to seal with a second nostril of the patient.

In some configurations, the first nasal delivery element 111 and the second nasal delivery element 112 are configured to seal with the nostril entrance of the patient. In some configurations, the first nasal delivery element 111 and the second nasal delivery element 112 are configured to seal with the inside of the patient's nostrils. In some configurations, the first nasal delivery element 111 and the second nasal delivery element 112 are configured to seal with the nostril entrance and nostril interior of the patient.

The nasal interface includes a gas manifold 120 that includes a gas inlet 121 for delivering breathing gas to the gas manifold. The first nasal delivery element 111 and the second nasal delivery element 112 are in fluid communication with a gas inlet 121 through a gas manifold 120.

The gas inlet 121 communicates with a single gas inlet portion of the gas flow channel 125 of the gas manifold. With this configuration, breathing gas enters the gas manifold 125 from a single region of the gas manifold (e.g., from a single side) and is delivered from the single region to the first and second nasal delivery elements 111, 112.

In addition to passing through the first and second nasal delivery elements 111, 112, the gas flows from one side of the gas manifold to the other side of the gas manifold in generally one direction.

The gas manifold 120 may include a single gas inlet 121.

Referring to fig. 9,10 and 11, the nasal interface includes a bypass restrictor 130 to provide a pressure drop between the first and second nasal delivery elements 111, 112 through the nasal interface 100 when gas is delivered from the gas inlet 121 to the first and second nasal delivery elements 111, 112 such that the pressure at the first nasal delivery element 111 is higher than the pressure at the second nasal delivery element 112.

As used herein, bypass restrictor 130 may be any feature or geometry that is capable of providing a pressure drop between first nasal delivery element 111 and second nasal delivery element through nasal interface 100 such that the pressure at first nasal delivery element 111 is higher than the pressure at second nasal delivery element 112 as gas is delivered from gas inlet 121 to first nasal delivery element 111 and second nasal delivery element 112. In some constructions, the bypass restrictor 130 can be a physical restrictor relative to an adjacent portion of the gas flow channel 125, relative to the gas inlet 121, relative to the combined cross-sectional areas a ₃+A₄ of the first and second nasal delivery elements 111, 112, and/or relative to any other portion of the nasal interface 100.

In some constructions, the bypass restrictor 130 can be a diverter or a deflector.

The pressure drop is such that the gas pressure upstream of the bypass flow restriction will be higher than the gas pressure downstream of the bypass flow restriction.

The pressure at the first nasal delivery element 111 may be at the outlet of the first nasal delivery element and/or along and/or adjacent to the first nasal delivery element. The pressure at the second nasal delivery element 112 may be at the outlet of the second nasal delivery element and/or along and/or adjacent to the second nasal delivery element.

The pressure drop across the gas manifold 120 may be such that the gas flow from the gas inlet 121 to the first nasal delivery element 111 is greater than the gas flow from the gas inlet 121 to the second nasal delivery element 112 when there is a gas flow from the gas inlet 121 to the first nasal delivery element 111 and the second nasal delivery element 112.

The bypass restrictor 130 may restrict the flow of gas through the gas manifold 120 between the first and second nasal delivery elements 111, 112.

In some configurations, when gas is delivered from the gas inlet 121 to the first nasal delivery element 111 and the second nasal delivery element 112, the gas flow pressure at the second nasal delivery element 112 is up to about 1cmH ₂ O less than the gas flow pressure at the first nasal delivery element.

The pressure drop caused by the bypass restrictor 130 and thus the pressure differential of the airflow between the first and second nasal delivery elements 111, 112 will typically be higher during the inspiratory phase than during the expiratory phase. This is because when the patient exhales, more of the exhaled gas will pass through the second nasal delivery element 112 than through the first nasal delivery element 111. For example, during the inhalation phase, the airflow pressure at the second nasal delivery element 112 may be about 0.6cmH ₂ O less than the airflow pressure at the first nasal delivery element 111, while during the exhalation phase, the airflow pressure at the second nasal delivery element 112 may be about 0.3cmH ₂ O less than the airflow pressure at the first nasal delivery element 111. The magnitude of the difference between the airflow pressure at the first nasal delivery element 111 and the airflow pressure at the second nasal delivery element 112 for a given bypass restrictor 130 will depend on the set pressure and the phase of the breathing cycle.

In some constructions, the nasal interface 100 is configured to achieve a patient pressure of between about 2cmH ₂ O and about 30cmH ₂ O at the first and second nasal delivery elements 111, 112 in use, optionally between about 2cmH ₂ O and about 25cmH ₂ O in use, optionally between about 2cm H ₂ O and about 20cm H ₂ O in use, optionally between about 2cm H ₂ O and about 15cm H ₂ O in use, Optionally between about 2cm H ₂ O and about 14cm H ₂ O in use, optionally between about 2cm H ₂ O and about 13cm H ₂ O in use, Optionally between about 2cm H ₂ O and about 12cm H ₂ O in use, optionally between about 2cm H ₂ O and about 11cm H ₂ O in use, optionally between about 2cmH ₂ O and about 10cmH ₂ O in use.

The nasal interface 100 may be configured such that the pressure at the first nasal delivery element 111 is higher than the pressure at the second nasal delivery element 112 in both the inhalation phase and the exhalation phase.

The set pressure may be delivered to the second nasal delivery element 112 and the higher pressure may be delivered to the first nasal delivery element 111.

When the set pressure increases, the pressure differential between the first and second nasal delivery elements increases, which provides for enhanced dead zone clearing or flushing.

In some configurations, the pressure differential between the first nasal delivery element 111 and the second nasal delivery element 112 is configured to provide an asymmetric flow of gas through the patient's upper airway of at least about 1 liter per minute (lpm), optionally between about 1lpm and about 2lpm, optionally between about 1lpm and about 5 lpm. In some configurations, the asymmetric gas flow may be less than 1lpm.

The nasal interface 100 is configured such that: an asymmetric airflow through the first and second nasal delivery elements 111, 112 is created at the patient's nostrils due to the pressure drop across the gas manifold and the pressure differential created between the first and second nasal delivery elements 111, 112. The resulting asymmetric airflow may provide improved dead zone cleaning.

In some constructions, the gas manifold 120 includes a gas flow passage 125 in the gas manifold 120, and the bypass restrictor 130 provides a reduced cross-sectional area of a portion of the gas flow passage 125.

This is illustrated, for example, in fig. 10, where it can be seen that the spacing of the gas flow channels 125 in the region of the bypass flow restrictor 130 is significantly reduced compared to the spacing of the gas flow channels 125 on both sides of the bypass flow restrictor 130.

The restriction of the gas flow channel 125 may be between the first nasal delivery element 111 and the second nasal delivery element 112 and/or may be adjacent to the second nasal delivery element 112. In particular, the restriction of the gas flow path may be between the first gas outlet 123 and the second gas outlet 124 of the gas manifold.

Fig. 19 schematically illustrates the configuration of the nasal interface of fig. 1-18, but also illustrates the relative cross-sectional areas of the bypass restrictor region (area a ₂) and the adjacent or main portion (area a ₁) of the gas flow passage 125. In this configuration, bypass restrictor 130 is shown as being located between first nasal delivery element 111 and second nasal delivery element 112.

In some constructions, the volumes of the chambers at the bases of the first and second nasal delivery elements 111, 112 are substantially the same. Bypass restrictor 130 may be a partial restrictor.

Fig. 20 schematically illustrates an alternative configuration of a nasal interface, wherein a bypass restrictor 130 is adjacent to the second nasal delivery element 112. The bypass restrictor 130 is positioned opposite the base of the second nasal delivery element 112.

Fig. 21 schematically illustrates an alternative configuration of a nasal interface, wherein a bypass restrictor 130 is located both between the first nasal delivery element 111 and the second nasal delivery element 112 and adjacent to the second nasal delivery element. The bypass restrictor 130 is partially opposite the base of the second nasal delivery element.

The volume in the gas flow channel 125 at the base of the second nasal delivery element 112 is less than the volume in the gas flow channel at the base of the first nasal delivery element 111.

The bypass flow restrictor 130 may extend into the gas flow passage in one or more directions (i.e., from one or more walls of the gas flow passage 125). In some configurations, the bypass restrictor 130 may extend into the gas flow passage in one direction (e.g., in an upward direction, a downward direction, a forward direction, or a rearward direction). In some configurations, the bypass restrictor 130 may extend into the gas flow passage in more than one direction (e.g., in more than one of an upward direction, a downward direction, a forward direction, or a rearward direction).

The bypass restrictor 130 may include at least one protrusion 130a, 130b that extends into the gas flow passage 135. In some constructions, the bypass restrictor 130 can include a plurality of protrusions extending into the gas flow channel 125.

For example, the bypass restrictor 130 may include diametrically opposed protrusions extending into the flow passage.

In some configurations, the gas manifold 120 includes proximal bypass protrusions 130a proximate to the first and second nasal delivery elements 111, 112 and/or distal bypass protrusions 130b distal to the first and second nasal delivery elements 111, 112.

In the illustrated construction, the gas manifold 120 includes both proximal and distal bypass protrusions 130a, 130b that in combination define a predetermined bypass dimension BD of the restricted gas flow through the gas manifold 120 between the first and second nasal delivery elements 111, 112.

The predetermined bypass dimension BD will generally be substantially smaller than the dimension of the adjacent or major portion of the gas flow channel 125.

The predetermined bypass dimension BD may be related to the cross-sectional area a ₂ described below.

When a plurality of protrusions are provided, they may be separate protrusions, semi-continuous or continuous. For example, fig. 11 (a) and (b) illustrate that a portion of the bypass flow restriction extends around substantially the entire perimeter of the gas flow passage 125 to form the upper and lower bypass protrusions 130a, 130b.

Referring to fig. 11 (c), the bypass flow restrictor 130 includes sloped leading edges 130a ', 130b' and sloped trailing edges 130a ", 130b" that define converging and diverging bypass flow restrictors in the direction of gas flow through the gas manifold from the first nasal delivery element 111 to the second nasal delivery element 112.

The angled leading edges 130a ', 130b' and/or the angled trailing edges 130a ", 130b" may be substantially straight or flat, or alternatively may be curved. If curved, the curved surface may be convex so as to curve in a direction toward the center of the gas flow channel 125, or may be concave so as to curve in a direction away from the center of the gas flow channel 125.

Any suitable combination of shapes may be provided. For example, at least one of the leading edges 130a ', 130b' may be one of straight, concave, or convex, and at least one of the trailing edges 130a ", 130b" may be the other of straight, concave, or convex.

The leading edges 130a ', 130b' and trailing edges 130a ", 130b" may have the same configuration as each other or may have different configurations from each other. For example, the gradient and/or curvature of the upstream side may be different from the gradient and/or curvature of the downstream side.

When a plurality of protrusions are provided for the bypass restrictor 130, the protrusions may have the same shape and configuration as each other, or may have different shapes and configurations from each other.

In the illustrated construction, the upper protrusion 130a has a shorter width in a direction along the gas flow path than the lower protrusion 130 b. In alternative constructions, the upper protrusion 130a may have the same width as the lower protrusion 130b, or may have a shorter width than the lower protrusion.

In the illustrated construction, the upper protrusion 130a extends into the gas flow channel 125 substantially the same distance as the lower protrusion 130 b. In alternative constructions, the upper protrusion 130a may extend further into the gas flow channel 125 than the lower protrusion 130b, or the lower protrusion 130b may extend further into the gas flow channel 125 than the upper protrusion 130 a.

The bypass restrictor 130 may be integrally formed with the gas manifold 120. Or the bypass restrictor 130 may include an insert for attachment to the gas manifold 120. For example, the bypass restrictor may be formed as a sleeve or plug. The sleeve or plug may be attached to the gas manifold in any suitable manner. For example, a sleeve or plug may be press fit, threaded, fastened, or the like into the gas flow channel 125 of the gas manifold.

The bypass restrictor 130 may be provided by the gas manifold 120, by the base 118 of the interface body, or by both the gas manifold 120 and the base 118 of the interface body.

The bypass restrictor 130 is configured to provide a reduced second cross-sectional area a ₂ in the gas flow channel 125 as compared to the first cross-sectional area a ₁ of an adjacent or main portion of the gas flow channel 125.

In some constructions, the second cross-sectional area a ₂ can be between about 10% and about 40% of the first cross-sectional area a ₁. In some constructions, the second cross-sectional area a ₂ can be between about 10% and about 35% of the first cross-sectional area a ₁. Optionally between about 10% and about 30% of the first cross-sectional area a ₁, optionally between about 10% and about 25% of the first cross-sectional area a ₁, optionally about 17.5% of the first cross-sectional area a ₁. In some constructions, the second cross-sectional area a ₂ can be about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, about 20%, about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, or about 40% of the first cross-sectional area a ₁, or can be any percentage between any two of these percentages.

In one exemplary configuration, the first cross-sectional area may be about 200mm ² (corresponding to a radius of about 8 mm), and the second cross-sectional area may be between about 20mm ² and about 80mm ², optionally between about 20mm ² and about 70mm ², optionally between about 20mm ² and about 60mm ², optionally between about 20mm ² and about 50mm ², optionally between about 30mm ² and about 40mm ², and optionally about 35mm ².

The predetermined bypass dimension BD may be, for example, between about 5mm and about 10mm, alternatively between about 5mm and about 9.5mm, alternatively between about 5mm and about 8.75mm, alternatively between about 5mm and about 8mm, alternatively between about 6mm and about 7mm, alternatively between about 6.5mm and about 7mm, and alternatively about 6.7mm.

In some constructions, the nasal interface 100 includes an interface body 110 that includes a first nasal delivery element 111 and a second nasal delivery element 112.

In some constructions, the gas manifold 120 is integral with the interface body 110 or separate from and coupleable with the interface body 110.

The first nasal delivery element 111 has a first outlet 111a defined by an opening at its end or terminal end 111b for delivering gas from the first nasal delivery element 111. The gas delivered by the first nasal delivery element 111 exits the first nasal delivery element 111 via the first outlet 111 a.

The second nasal delivery element 112 has a second outlet 112a defined by an opening at its end or terminal end 112b for delivering gas from the second nasal delivery element 112. The gas delivered through the second nasal delivery element 112 exits the second nasal delivery element via a second outlet 112 a.

The first and second nasal delivery elements 111, 112 may have any suitable shape that seals with the nostrils of the patient. For example, in one configuration, the first and second nasal delivery elements 111, 112 may be substantially tubular and sized to be larger than the patient's nostrils, but may be pliable or flexible to deform and seal with the nostrils when inserted therein. In some constructions, the nasal delivery elements 111, 112 are more flexible or more flexible than the body portion 118.

As another example, as shown, the first and second nasal delivery elements 111, 112 may include nostril positioning portions or nasal pillows to seal with the nostrils of the patient.

In the illustrated configuration, for example, as shown in fig. 13 and 14, each nasal pillow may be generally tapered such that it narrows toward a respective outlet 111a, 112a at the ends or terminal ends 111b, 112 b. In this way, the proximal openings 111a, 112a may be smaller in diameter or lateral dimension than the distal openings 111c, 112c at the base of the nasal pillows. In general, the nasal pillows may taper in a proximal direction toward the ends or terminal ends 111b, 112 b.

In the illustrated construction, the ends or terminals 111b, 112b of the nasal pillows are configured to be received in the nostrils of the patient, while the enlarged regions 111d, 112d of the nasal pillows adjacent the ends or terminals 111b, 112b are configured to seal the nostril inlets. In other constructions, the ends or terminals 111b, 112b and a portion of the enlarged regions 111d, 112d may be configured to be received in the nostrils to seal with the nostrils.

The nasal pillows may be flexible or pliable to deform and seal with the nostrils when inserted into or in contact with the nostrils. In some constructions, the nasal pillows are more flexible or more flexible than the main body portion 118.

The nasal pillows are also preferably sufficiently rigid to reduce the likelihood of swelling or insufficient self-support to provide an indication to the user of the correct positioning and orientation of the nasal interface 100 relative to the face. The nasal pillows may be sufficiently rigid to inhibit or prevent significant collapse in response to positioning of the nasal pillows relative to the patient's nostrils. In some constructions, the nasal pillows may have a thickness of about 0.7mm, and some variations may be slightly larger or smaller, with the aim of reducing user discomfort while still facilitating nasal interface positioning.

The nasal pillows may include one or more stiffening elements or features to inhibit collapse of the nasal pillows.

The first and second nasal delivery elements 111, 112 are movable relative to the body portion 118 to enable adjustment of the angle and positioning of the nasal delivery elements 111, 112 in response to contact with the patient's nostrils.

The nasal pillows and nasal interfaces may have any one or more of the features described with respect to the nostril positioning portions of U.S. patent 10,918,818. The content of this patent specification is incorporated herein by reference in its entirety.

If any leakage occurs between the nasal delivery elements 111, 112 and the patient's nostrils, the leakage will be minimal and can be compensated or controlled by adjusting the therapeutic gas flow.

The nasal interface 100 is configured to create an asymmetric airflow at the patient's nares due to the pressure drop across the gas flow path 125 of the nasal interface 100.

The nasal interface 100 may be configured such that about 10lpm to about 50lpm is delivered out of the nasal interface 100 through the nasal delivery elements 111, 112. The proportion delivered by each nasal delivery element will vary depending on the patient, the pressure differential, and the stage of the respiratory cycle.

Having different flow rates between the nasal delivery elements 111, 112 may provide the benefits of asymmetric airflow described below.

In some configurations, there is a relatively constant pressure differential between the nasal delivery elements 111, 112 and a relatively constant asymmetric airflow is generated through the nasal delivery elements 111, 112. In some configurations, the pressure differential and the resulting asymmetric airflow may vary. An asymmetric flow of gas occurs as long as there is a pressure drop across the gas manifold 120 during at least some portions of the respiratory cycle.

The proportion of the total volume flow delivered through each nasal prong 111, 112 may be determined by delivering a gas having a known volume flow to the gas inlet 121 of the nasal interface 100 when the nasal interface is not applied to the patient's nostrils. The volumetric flow rate exiting each outlet 111a, 112a may be measured by a suitable flow meter or sensor to determine the proportion of the total volumetric flow rate of the gas flow flowing into the gas inlet 121 exiting the outlet 111a, 112a of each nasal delivery element 111, 112.

The nasal interface 100 includes a bias flow restrictor 140 for the flow of gas out of the nasal interface 100 and optionally out of the gas manifold 120.

Referring to fig. 1-5, 16 and 18, the bias flow restrictor 140 is in fluid communication with the gas manifold 120, and more particularly with the gas port 122 of the gas manifold 120.

The bias flow restrictor 140 is positioned in the patient interface 100 downstream of the first and second nasal delivery elements 111, 112 and opposite the gas port 121 so that gas can pass from the first and second nasal delivery elements 111, 112 and out of the nasal interface via the bias flow restrictor 140. Some of the gas entering the gas inlet 121 may flow from the bias flow restrictor 140 without passing through the first and second nasal delivery elements 111, 112. The gas exiting the nasal interface via the bias flow restrictor may comprise exhaled gas and may also comprise some inlet gas that has not passed through the first and second nasal delivery elements 111, 112.

The bias flow restrictor 140 allows for providing pressure therapy to the patient's nostrils. The bias flow restrictor 140 enables the restricted airflow to flow out of the nasal interface 100 through the bias flow restrictor. If there is no bias flow restrictor 140 and the gas port 122 is closed, all exhaled gas will be re-inhaled. Without a bias flow restrictor and with the gas port 122 open, the respiratory therapy device will not be able to apply pressure through the nasal interface.

The open area for the airflow to flow through the bias flow restrictor may be selected to provide sufficient area for the bias flow while minimizing noise from the bias flow. In one exemplary configuration, when patient pressure of about 10cmH ₂ O is provided, the airflow through the nasal interface 100 may be about 25-45lpm, and the open area for airflow through the bias flow restrictor may be between about 10mm ² and about 15mm ². However, this is only one example, and these values may vary depending on the system parameters and patient needs. In another example, the open area for airflow through the bias flow restrictor may be between about 10mm ² and about 30mm ², alternatively between about 25mm ² and about 30mm ², and alternatively about 27.5mm ².

The gas manifold 120 can include a bias flow restrictor 140 or can be coupled to the bias flow restrictor 140. In an alternative configuration shown in fig. 18, the bias flow restrictor 140 may be in fluid communication with the gas manifold 120, but located remotely from the gas manifold 120. In this alternative configuration, the exhalation gas conduit 160 is coupled to the gas ports 122 and the bias flow restrictor 140 of the gas manifold 120. The exhalation gas conduit 160 may have any suitable length. This configuration enables the exhaled gas and any inlet gas bypassing the first and second nasal delivery elements 111, 112 to be exhausted through the bias flow restrictor 140 at a location spaced from the patient.

Referring to fig. 6-9, the bias flow restrictor 140 includes one or more gas outlets for allowing gas flow from the nasal interface 100 and optionally from the gas manifold 120 to the ambient environment.

The one or more gas outlets may comprise one or more holes. In the illustrated construction, the one or more gas outlets include a plurality of apertures 142 for the flow of gas from the nasal interface 100 and optionally from the gas manifold 120 to the ambient environment.

The plurality of apertures 142 may be provided in any suitable arrangement or array. For example, in the illustrated construction, the plurality of apertures 142 are arranged in an array of four long rows and two outer short rows. However, any other suitable arrangement may be provided, such as more or fewer rows of holes, more or fewer holes in each row, or a random arrangement of holes.

The bias flow restrictor 140 may comprise 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 or more holes.

Additionally or alternatively, the one or more gas outlets may comprise one or more slits, which may be straight, curved, wavy, serpentine, or any other suitable shape.

The outlet dimension of the one or more gas outlets is typically substantially smaller than the dimension of the gas inlet of the bias flow restrictor 140 to create a pressure drop or resistance to the flow of gas out of the one or more gas outlets. The pressure drop is such that the gas pressure upstream of the one or more gas outlets will be higher than the gas pressure downstream of the one or more gas outlets.

However, when multiple outlets are provided, the sum of the outlet dimensions may approximate the size of the gas inlet.

In some configurations, the gas inlet 148 and the one or more gas outlets are disposed in the flow diverter flow restrictor 140 such that the gas flow F needs to be redirected between entering the flow diverter flow restrictor and exiting the flow diverter flow restrictor. This is indicated for example by arrow F in fig. 7.

In some constructions, the one or more gas outlets are disposed in the flow-restricting member body 144. The flow restrictor body 144 defines a body gas flow path 146 in fluid communication with a body gas inlet 148. The one or more gas outlets are in fluid communication with the body gas flow path 146 such that gas enters the body gas flow path 146 from the gas port 122 of the gas manifold and exits from the one or more gas outlets (e.g., the aperture 142).

For example, as shown in fig. 7 (b), the flow restricting member body 144 may have a tapered configuration in which the body gas flow passage 146 becomes smaller away from the body gas inlet 148 than near the body gas inlet 148. The top wall, end wall 144b, and/or wall 144c of the body containing the one or more gas outlets may be sloped so as to be non-parallel and non-perpendicular with respect to each other to facilitate the flow of gas from the body gas inlet 148 through the one or more gas outlets.

In some constructions, the bias flow restrictor 140 is configured to direct the flow of gas out of the bias flow restrictor away from the patient's face. In the illustrated configuration, the bias flow restrictor 140 is configured to direct the flow of air at least partially in a forward direction, and in some configurations, entirely in a forward direction away from the patient's face.

The bias flow restrictor 140 enables carbon dioxide (CO ₂) to be discharged through the use of the one or more gas outlets. In the illustrated embodiment, the nasal interface 100 has an aperture 142 for venting gases from the interior of the nasal interface 100 to the environment. The holes 142 or other openings may assist in venting carbon dioxide gas from the user to reduce re-inhalation of carbon dioxide gas.

The one or more gas outlets create a controlled or known leak to enable venting of carbon dioxide gas exhaled by the user. There may be a performance tradeoff between the location of the one or more openings (relative to the patient's nose) and the amount of bias flow required. As used herein, bias flow refers to airflow to the environment through bias flow restrictor 140. The flow rate of the bias flow and the design geometry of the one or more openings can have an effect on the noise level created by the bias flow and the ventilation air flow and the amount of entrainment that can be caused by the exiting air flow.

The one or more gas outlets may include a plurality of through holes 142 that vent gas from the nasal interface. In other constructions, the gas outlet may be a slit or a large opening instead of or in addition to the small through holes. In some constructions, the gas outlet may be provided on other portions of the interface. In general, relatively smaller pore sizes produce less airflow noise than larger pore sizes, with the same flow rate through both large and small pore sizes. The plurality of holes helps to reduce airflow noise when a given volume of gas is exhausted, as compared to one or several holes having the same exhaust port area.

The one or more gas outlets may have any one or more of the features or functions described in U.S. patent 10,898,866 for the exhaust ports. The content of this patent specification is incorporated herein by reference in its entirety.

The flow diverter 140 may include an optional filter or diffuser to filter or diffuse the gas flowing through the one or more gas outlets (e.g., through the holes).

The filter may mitigate respiratory contaminants released through the bias flow restrictor.

The diffuser may diffuse the gas exiting the flow restrictor to reduce noise.

Fig. 6 shows a filter or diffuser member 150 configured to cover the at least one or more gas outlets so as to filter or diffuse the gas as it exits the one or more gas outlets. The filter or diffuser member 150 may comprise any suitable material, such as one or more of a nonwoven fibrous material (including polymeric fibers), an open cell foam, a sintered polymer.

In some constructions, the flow restriction member body 144 includes a filter or diffuser recess 145 to receive a filter or diffuser member 150.

The flow-deflecting restrictor 140 may include a shroud 152 configured to attach to the flow-restrictor body 144 and to retain the filter or diffuser member 150 positioned over the one or more gas outlets.

The shroud 152 includes an aperture 153 that is at least the size of the at least one opening of the flow restriction member body 144.

The shroud 152 may carry the filter or diffuser member 150 in the aperture 153, or the filter or diffuser member 150 may be sandwiched between the shroud 152 and the recess 145.

The shroud 152 may be removably attached to the flow restrictor body 144 to enable the filter or diffuser member 150 to be cleaned or replaced.

The shroud 152 may be attached to the flow restricting member body 144 by any suitable arrangement (e.g., clips, fasteners, etc.). In the illustrated construction, the shroud 152 includes two inward engagement members 154 that snap fit into complementary engagement recesses 147 on the flow-restricting member body 144.

The shroud may include one or more grips 156 to enable the engagement member 154 to be released from the recess 147 to detach the shroud 152 from the flow-restricting member body 144. In the illustrated configuration, the grip 156 includes an outward projection to enable a user to apply a force in an outward and downward direction to force the engagement member out of engagement from the flow restricting member body 152, although any other suitable configuration may be used.

In some constructions and as shown in fig. 17 (b), a filter unit 500' may be provided between the gas manifold 120 and the bias flow restrictor 140. The filter unit 500' may have any one or more of the features described herein with respect to the filter unit 500.

In some constructions, the nasal interface 100 of the present disclosure includes: a first nasal delivery element 111 and a second nasal delivery element 112, wherein the first nasal delivery element 111 and the second nasal delivery element 112 are each configured to seal with a respective nostril of a patient; and a gas manifold 120 comprising a gas inlet 121 for delivering respiratory gas to the gas manifold, wherein the first nasal delivery element 111 and the second nasal delivery element 112 are in fluid communication with the gas inlet 121 via the gas manifold 120, wherein the first nasal delivery element 111 is proximal to the gas inlet 121 and the second nasal delivery element 112 is distal to the gas inlet 121, wherein the nasal interface 100 is configured to create a pressure differential between the first nasal delivery element 111 and the second nasal delivery element 112 when gas is delivered from the gas inlet 121 to both the first nasal delivery element 111 and the second nasal delivery element 112 such that the pressure at the first nasal delivery element 111 is higher than the pressure at the second nasal delivery element 112.

In some constructions, the pressure differential is such that when there is a flow of gas from the gas inlet 121 to the first nasal delivery element 111 and the second nasal delivery element 112, the flow of gas from the gas inlet 121 to the first nasal delivery element 111 is greater than the flow of gas from the gas inlet 121 to the second nasal delivery element 112.

In some constructions, the gas inlet 121 is in fluid communication with the breathing conduit 300.

In some configurations, when gas is delivered from the gas inlet to both the first and second nasal delivery elements, the gas flow pressure at the second nasal delivery element 112 is up to about 1cmH ₂ O less than the gas flow pressure at the first nasal delivery element 111.

For example, the air flow pressure at the second nasal delivery element 112 may be about 0.1cmH ₂ O, about 0.2cmH ₂ O, about 0.3cmH ₂ O, about 0.4cmH ₂ O, about 0.5cmH ₂ O, about 0.6cmH ₂ O, about 0.7cmH ₂ O, about 0.8cmH ₂ O, about 0.9cmH ₂ O, or about 1cmH ₂ O less than the air flow pressure at the first nasal delivery element 111, or the difference may be any value between any two of these values.

The air flow differential between the first nasal delivery element and the second nasal delivery element may be higher during the inspiratory phase than during the expiratory phase.

The nasal interface may be configured to achieve a patient pressure at the first nasal delivery element and the second nasal delivery element of between about 2cmH ₂ O and about 30cmH ₂ O, in use, optionally between about 2cmH ₂ O and about 25cmH ₂ O, Optionally between about 2cm H ₂ O and about 20cm H ₂ O in use, optionally between about 2cm H ₂ O and about 15cm H ₂ O in use, Optionally between about 2cm H ₂ O and about 14cm H ₂ O in use, optionally between about 2cm H ₂ O and about 13cm H ₂ O in use, Optionally between about 2cm H ₂ O and about 12cm H ₂ O in use, optionally between about 2cm H ₂ O and about 11cm H ₂ O in use, In use, may be selected to be between about 2cmH ₂ O and about 10cmH ₂ O.

In some configurations, the pressure differential between the first nasal delivery element 111 and the second nasal delivery element 112 is configured to provide an asymmetric flow of gas through the upper airway of the patient of between about 1 liter per minute (lpm) and about 5 lpm.

For example, the asymmetric flow of gas through the upper airway of the patient may be about 1lpm, about 1.25lpm, about 1.5lpm, about 1.75lpm, about 2lpm, about 2.25lpm, about 2.5lpm, about 2.75lpm, about 3lpm, about 3.25lpm, about 3.5lpm, about 3.75lpm, about 4lpm, about 4.25lpm, about 4.5lpm, about 4.75lpm, about 5lpm, or any value between any two of these values.

The asymmetric gas flow facilitates cleaning of CO ₂ from the patient anatomical dead space.

As described above, the interface body 110 may be engageable with the gas manifold 120. Thus, in some configurations, the nasal interface 100 of the present disclosure includes an interface body 110 component comprising a first nasal delivery element 111 and a second nasal delivery element 112, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of a patient. The nasal interface 100 of the present disclosure further includes a gas manifold 120 component that includes a gas inlet 121 for delivering breathing gas to the gas manifold component. The interface body 110 component may be engaged with the gas manifold 120 component to place the first and second nasal delivery elements 111, 112 in fluid communication with the gas inlet 121 such that the first nasal delivery element 111 is closer to the gas inlet 121 and the second nasal delivery element 112 is farther from the gas inlet 121. The nasal interface 100 includes at least one gas flow restrictor 130 to restrict the flow of gas through the nasal interface such that when gas is delivered from the gas inlet 121 to the first nasal delivery element 111 and the second nasal delivery element 112, the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element.

The at least one restriction may comprise a bypass restriction. The bypass restrictor may have any one or more of the features and functions described herein with respect to bypass restrictor 130.

In some constructions, the nasal interface further comprises a bias flow restrictor. The bias current flow restrictor may have any one or more of the features and functions described herein with respect to bias current flow restrictor 140.

Thus, the nasal interfaces described herein may include a bypass restrictor, a bias flow restrictor, or may include both a bypass restrictor and a bias flow restrictor.

By providing an asymmetric flow of gas, use of the nasal interface 100 of the present disclosure may provide a reduction in dead space (i.e., volume of air not involved in intra-pulmonary gas exchange) as compared to conventional Continuous Positive Airway Pressure (CPAP) therapy. It should be appreciated that within the patient's upper airway, some proportion of the gas moves in a unidirectional manner, flowing into one naris and out of the other naris, thereby reducing upper airway dead space. This may be most pronounced at higher set pressures, which lead to an increase in asymmetric airflow and thus to an increase in dead zone cleaning.

Bypass restrictor 130 facilitates asymmetric airflow. The bias flow restrictor 140 in conjunction with the sealing nose elements 111, 112 allows CPAP type treatment to be provided. The nasal interface 100 enables CPAP with enhanced dead band clearance. Bypass restrictor 130 enables dead zone cleaning. The sealing nasal delivery elements 111, 112 are capable of CPAP therapy.

Inhalation and exhalation flows will exist in both nostrils. However, the airflow is a partial unidirectional airflow in which a greater proportion of the inspiratory airflow will pass through the nostrils proximate the gas inlet 121 and thus the airflow source.

The nasal interface 100 may be used for pressure controlled therapy, but with a higher humidity than conventional CPAP therapy. Higher humidity is believed to be advantageously able to cooperate with enhanced dead zone cleaning.

In some configurations, the nasal interface 100 may be adapted or may be used for pressure controlled therapy at a pressure between about 2cmH ₂ O and about 10cmH ₂ O, depending on patient needs and therapy requirements.

For example, the nasal interface may be suitable for or may be used in pressure controlled therapies at about 2cmH ₂O、2.5cmH₂O、3cmH₂O、3.5cmH₂O、4cmH₂ O, about 4.5cmH ₂ O, about 5cmH ₂ O, about 5.5cmH ₂ O, about 6cmH ₂ O, about 6.5cmH ₂ O, about 7cmH ₂ O, about 7.5cmH ₂ O, about 8cmH ₂ O, about 8.5cmH ₂ O, about 9cmH ₂ O, about 9.5cmH ₂ O, or about 10cmH ₂ O.

The pressure may be set or controlled by the respiratory therapy system, an example of which is described below.

To maintain the desired pressure, the flow is provided and the flow will depend on factors such as the phase of the breathing cycle and the geometry of the bias flow restrictor 130.

Fig. 10 (a) and (b) show the airflow through the nasal interface 100. As gas flow F enters flow channel 125 of gas manifold 120, gas flow portion F1 will travel through upstream first nasal delivery element 111 and through the patient's upper airway. The airflow portion F2 will travel past the bypass restrictor 130. The portion of the airflow F2 that travels past the bypass restrictor 130 causes the airflow F3 to pass through the downstream second nasal delivery element 111, so inhalation may occur through both nasal delivery elements 111, 112 (assuming that neither naris is blocked).

The airflow F will preferentially enter the upstream naris during inspiration and will be slightly more airflow into the upstream naris than into the downstream naris. During exhalation, the airflow will preferentially leave the downstream naris (airflow F5), and since airflow F3 is smaller than F1, more airflow will leave the downstream naris than will leave the upstream naris (airflow F4).

When holding the breath, a portion of the airflow will flow into the upstream naris and out of the downstream naris, as the airflow F1 into the upstream naris is higher than the airflow F3 into the downstream naris.

The geometry of the bias flow restrictor 140 will define the positive flow volume through the nasal interface 100. A larger area for bias flow will result in a higher gas source flow required to achieve the desired therapeutic pressure.

The bypass flow restrictor 130 causes a pressure drop between the gases F1 and F3 delivered to the upstream and downstream nostrils, thereby creating a pressure differential at the first and second nasal delivery elements 111, 112.

The pressure drop results in an asymmetric gas flow, which results in a "flush" or "clean" dead zone, which is the volume of gas that does not participate in the intra-alveolar gas exchange and consists primarily of CO 2.

In some configurations, the asymmetric gas flow configuration may be between about 1lpm and about 5 lpm.

In some configurations, the pressure at the downstream naris may be about 1cmH ₂ O lower than the pressure delivered to the upstream naris, e.g., about 6cmH ₂ O at the upstream naris and about 5cmH ₂ O at the downstream naris.

The bias flow restrictor 140 may be configured to avoid negative flow during the provision of respiratory therapy.

It is recognized that negative flow contributes to dead space or re-inhalation. Accordingly, the bias flow restrictor 140 should be large enough to achieve a sufficiently high bias flow so that negative flow occurrence and re-inhalation is reduced or eliminated.

The asymmetric flow will reduce the amount of gas re-inhaled during the entire respiratory cycle when ventilating the upper airway volume.

This may alternatively be described as reducing dead space or reducing the amount of gas that does not participate in the gas exchange during the breathing cycle.

The effect of reducing dead space can also be seen in, for example, high flow therapies.

This reduces CO ₂ re-inhalation and increases the amount of oxygen available for gas exchange.

The delivered gas may require higher additional humidity than is typically used for non-invasive ventilation (NIV) or Continuous Positive Airway Pressure (CPAP) therapy. This extra humidity is to prevent the upper airway from drying out when the gas is replaced by the therapeutic supply gas in the dead space.

The anatomical dead volume for a given patient may typically be between 100ml and 150 ml.

The bypass airflow caused by the bypass restrictor 130 causes: in response to the device delivering a combination of airflow and respiration, or during an apnea, a pressure differential exists between the two nostrils. Some possible configurations of the bypass restrictor may be as described, however, in alternative configurations of the bypass restrictor this may be achieved by one or a combination of two or more of the following:

The bypass airflow is restricted, for example by having a reduced cross-section or some element to create such a restriction, for example one or more protrusions or nozzles or some other way of reducing the cross-section.

The bypass restrictor geometry may be designed such that it preferentially travels in one direction rather than the other, for example by employing a geometry with a higher pressure drop in one direction than the other, such as a bellmouth nozzle or restrictor, low pressure ejector or check valve.

Flexible elements or valves that create preferential (but not exclusive) flow from the upstream to the downstream direction.

A valve that is made user-adjustable by means of screws or some other mechanism to vary the cross-sectional area through which the bypass air flow passes.

The air flow enters the first nasal delivery element at an angle axially, radially, tangentially or some combination of these flow regimes to preferentially direct the air flow to the first nasal delivery element over the second nasal delivery element.

The bypass restrictor comprises a sparse network of materials that create a pressure drop, such as a filter, nonwoven polypropylene, foam, sintered material, or any other material that creates a pressure drop across the gas stream when present.

The bypass restrictor may include any one or more of the features described in US 2016/0228665. The content of this patent specification is incorporated herein by reference in its entirety.

The total bias current is controlled primarily by selecting the geometry of the entire bias current restrictor 140. Some possible configurations of the bias flow restrictor may be as described, however, in alternative configurations, the pressure drop of the bias flow restrictor may be achieved by one or a combination of two or more of the following:

Flow restriction is performed, for example, by having a reduced cross-section or some element to create such a restriction, for example one or more members or nozzles or some other way of cross-section reduction.

A flexible element or valve that creates a preferential and possibly exclusive outflow nasal interface to reduce or prevent entrainment of ambient air.

Check valves can be used to reduce/prevent entrainment of ambient air.

The flexible element may be used to create a pressure drop that is less prone to clogging than a rigid orifice/nozzle in the presence of water or sputum.

There may be a sparse network of materials that create a pressure drop, such as filters, nonwoven polypropylene, foam, sintered materials, or any other material that creates a pressure drop across the gas stream when present.

A valve that is adjustable by a user, by means of screws or some other mechanism, to vary the cross-sectional area of the air flow.

-Changing the direction of the air flow a plurality of times.

The pressure drop of the nasal interface 100 may be relatively constant over the patient's breathing cycle, or alternatively may vary over the patient's breathing cycle.

Table 1 summarizes the different airflows that may be encountered during use of the nasal interface 100, with reference to fig. 15.

TABLE 1 summary of air flows

In fig. 15, the positive flow is in the direction of the arrow, and the negative flow is opposite to the direction of the arrow. Either means that the air flow can move in either direction based on a number of factors. Zero means that there is no net flow in this case.

If the upstream naris is completely plugged, the patient will receive airflow to the downstream naris.

If the downstream naris is completely plugged, the patient will receive airflow through the upstream naris.

In both cases, the patient will not receive any asymmetric airflow, but will continue to be provided with treatment without such a component.

If either naris is substantially but not completely plugged, there will be a reduced amount of asymmetric airflow.

The device may be used in a similar patient population suitable for non-invasive ventilation (NIV).

The nasal circulation may introduce fluctuations in the asymmetric airflow provided by the nasal interface 100.

As schematically shown in fig. 15, the nasal interface 100 forms a circuit with the patient's upper airway and lungs. The first portion of the circuit includes a first nasal delivery element 111, a patient's upstream nostril associated with the first nasal delivery element 111, a patient's upper airway and lungs, a second nasal delivery element 112, and a patient's downstream nostril associated with the second nasal delivery element 112. The second portion of the loop includes the first nasal delivery element 111, the bypass restrictor 130, and the second nasal delivery element 112. The bypass restrictor provides a pressure drop across the gas manifold between the first and second nasal delivery elements 111, 112, which results in an asymmetric gas flow through the first and second nasal delivery elements 111, 112.

The nasal interface 100 creates a pressure differential between the two nostrils such that the upstream nostril is at a higher pressure than the downstream nostril during at least some portions of the respiratory cycle.

The pressure differential creates a flow of gas within the upper airway, wherein after one complete respiratory cycle, more gas flow has entered the upstream naris than the downstream naris and more gas flow has exited the downstream naris than the upstream naris. This additional flow into the upstream naris and out of the downstream naris is an asymmetric airflow.

The asymmetric gas flow dilutes the gas in the patient's airway, which is known in the art as flushing or dead space purging.

There are a number of ways in which this pressure differential may be achieved between the inlets of the two nostrils, including having a bypass airflow between the two nostrils that is adjusted to provide a certain pressure drop.

In some configurations of the nasal interface 100, the gas manifold 120 may be configured to allow the breathing conduit 300 to be connected to either the right side of the gas manifold (fig. 16 (a)) or the left side of the gas manifold (fig. 16 (b)). That is, the respiratory conduit 300 and optionally the bias flow restrictor 140 may be reversed in side with respect to the gas manifold 120. This enables the breathing conduit 300 to be positioned to the right or left of the patient in use.

In some configurations, the gas ports 121, 122 may have the same configuration as each other, such that the respiratory tract 300 may be selectively coupled with either of the gas ports 121, 122. The gas port to which the patient breathing conduit is connected will form the gas inlet of the gas manifold 120 and the opposite gas port will form the gas outlet of the gas manifold. For example, in the configuration of fig. 16 (a), the gas port 121 would form a gas inlet, and the first nasal delivery element 111 would form an upstream nasal delivery element closer to the gas inlet. In the configuration of fig. 16 (b), the gas port 122 will form a gas inlet, and the second nasal delivery element 112 will form an upstream nasal delivery element closer to the gas inlet.

The internal features of the gas manifold 120 may be symmetrical such that the performance of the nasal interface 100 does not vary depending on which side of the gas manifold the respiratory conduit 300 is connected to.

When provided, the bias flow restrictor 140 can be selectively coupled with either of the gas ports 121, 122 and opposite the respiratory catheter 300. The respiratory catheter 300 and the bias flow restrictor 140 may have the same coupling features as each other.

Although the respiratory conduit 300 may be selectively connected to either side of the gas manifold 120, at any stage during nasal interface use, one of the ports 121, 122 will serve as a single gas inlet to the gas manifold 120. The other of the ports 121, 122 will typically function as a gas outlet for a gas manifold to deliver gas to the bias flow restrictor 140.

The nasal interface 100 may be provided with one or more pressure ports to allow pressure measurements for controlling respiratory therapy devices or for reporting purposes. The pressure ports may be disposed upstream and/or downstream and/or within the nasal interface 100.

Gases entering and/or exiting the nasal interface 100 may be filtered. Upstream and/or downstream filters may be provided for this purpose.

In the illustrated construction, the patient interface 1 includes a filter 500 in fluid communication with the breathing conduit 300 to filter gases entering the breathing conduit 300.

The filter may have any one or more of the features and functions of the filter of U.S. patent 6,619,287. The content of this patent specification is incorporated herein by reference in its entirety.

It may be desirable to configure the cross-sectional area of bypass restrictor 130 as wide as possible to enhance patient comfort. However, increasing the cross-sectional area of the bypass restrictor 130 risks reducing asymmetric airflow. That is, increasing the cross-sectional area of the bypass restrictor 130 reduces the degree of restriction, which in turn reduces the pressure differential between the upstream and downstream nasal delivery elements 111, 112 for driving asymmetric airflow and irrigation.

As described above, the bypass restrictor 130 may be any feature or geometry capable of providing a pressure drop between the first and second nasal delivery elements 111, 112 through the nasal interface 100 such that the pressure at the first nasal delivery element 111 is higher than the pressure at the second nasal delivery element 112 as gas is delivered from the gas inlet 121 to the first and second nasal delivery elements 111, 112. In some constructions, the bypass restrictor 130 can be a physical restrictor relative to an adjacent portion of the gas flow channel 125, relative to the gas inlet 121, relative to the combined cross-sectional areas a ₃+A₄ of the first and second nasal delivery elements 111, 112, and/or relative to any other portion of the nasal interface 100.

The inventors have found that effective asymmetric airflow can be maintained over a wide range of ratios of bypass restrictor cross-sectional area to combined nasal delivery element cross-sectional area. This may allow for optimizing patient comfort while maintaining a therapeutically effective asymmetric airflow.

A therapeutically effective asymmetric flow of gas may be provided by fully flushing the patient's upper airway dead space. The flush level may be at least about 10% of the patient upper airway volume, alternatively at least about 20% of the patient upper airway volume, alternatively at least about 30% of the patient upper airway volume, alternatively at least about 40% of the patient upper airway volume, alternatively at least about 50% of the patient upper airway volume, alternatively at least about 60% of the patient upper airway volume, alternatively at least about 70% of the patient upper airway volume, alternatively at least about 80% of the patient upper airway volume, alternatively at least about 90% of the patient upper airway volume, alternatively about 100% of the patient upper airway volume. In some configurations, the flush level may be determined within a single respiratory cycle.

The ratio of the bypass restrictor 130 cross-sectional area a ₂ to the combined nasal delivery elements 111, 112 cross-sectional area a ₃+A₄ helps to achieve asymmetric airflow and thus helps to achieve effective irrigation. The bypass restrictor 130 cross-sectional area a ₂ and the combined nasal delivery element 111, 112 cross-sectional area a ₃+A₄ are cross-sectional areas or internal cross-sectional areas for airflow. The cross-sectional area a ₃+A₄ of the combined nasal delivery elements 111, 112 may be the smallest lateral dimension of the respective nasal delivery element 111, 112.

Bypass restrictor 130 drives asymmetric airflow by restricting airflow to downstream nasal delivery element 112 relative to upstream nasal delivery element 111. Thus, the cross-sectional area a ₂ of the bypass restrictor 130 should be sufficiently narrow (or in other words sufficiently restricted) relative to the cross-sectional area a ₃+A₄ of the combined nasal delivery elements 111, 112 to achieve a restrictor and thus a pressure differential.

However, it is also desirable that the cross-sectional area a ₂ of the bypass restrictor 130 be as wide as possible in order to increase patient comfort and therapeutic diversity. In particular, it is desirable that the cross-sectional area A ₂ of the bypass restrictor 130 be wide enough so that if the upstream nasal delivery element 111 or nostril is blocked during treatment, the patient may still receive CPAP treatment through the downstream nasal delivery element 112. Increasing inspiration may cause the patient to feel lack of air. Making the bypass restrictor 130 cross-sectional area a ₂ larger means that a greater portion of the airflow flows through the downstream nasal delivery element 112 to the downstream naris upon inhalation. This reduces the pressure drop experienced by the patient and reduces this discomfort. However, making the bypass restrictor 130 larger in cross-sectional area A ₂ will result in treatment approaching conventional CPAP treatment where there is no therapeutically effective asymmetric flow. Patients undergoing conventional CPAP therapy may feel more comfortable with less restriction because the device may more easily control airflow, thereby reducing flow rate and reducing noise and spray sensations in the nostrils.

In some constructions, the nasal interface 100 of the present disclosure includes: a first nasal delivery element 111 and a second nasal delivery element 112, wherein the first nasal delivery element 111 and the second nasal delivery element 112 are each configured to seal with a respective nostril of a patient; and a gas manifold 120 comprising a gas inlet 121 for delivering respiratory gas to the gas manifold 120 and the gas flow channel 125, wherein the first nasal delivery element 111 and the second nasal delivery element 112 are in fluid communication with the gas inlet 121 through the gas flow channel 125, wherein the first nasal delivery element 111 is proximal to the gas inlet 121 and the second nasal delivery element 112 is distal to the gas inlet 121, wherein the nasal interface comprises a bypass restrictor 130 providing a cross-sectional area a ₂ of a portion of the gas flow channel 125, wherein each of the first nasal delivery element 111 and the second nasal delivery element 112 comprises an inner cross-sectional area a ₃、A₄, wherein the inner cross-sectional areas a ₃、A₄ together provide a combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and wherein the cross-sectional area a ₂ of the portion of the gas flow channel 125 is greater than 0 to about 1.5 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements.

Such a configuration with the relative cross-sectional areas may be used in any of the nasal interfaces 100 disclosed herein.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel is 0.25 to about 1.5 times the combined cross-sectional area a ₃+A₄ of the nasal delivery element.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel is up to about 1.3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery element, alternatively up to about 1 times the combined cross-sectional area a ₃+A₄ of the nasal delivery element, alternatively up to about 2/3 of the combined cross-sectional area a ₃+A₄ of the nasal delivery element, alternatively up to about 1/2 of the combined cross-sectional area a ₃+A₄ of the nasal delivery element, alternatively up to about 2/5 of the combined cross-sectional area a ₃+A₄ of the nasal delivery element, alternatively up to about 1/3 of the combined cross-sectional area a ₃+A₄ of the nasal delivery element.

In some constructions, the cross-sectional area of the portion of the gas flow passage, a ₂, is greater than 0mm ² and up to about 375mm ², optionally between about 1mm ² and about 375mm ², optionally between about 1mm ² and about 250mm ², optionally between about 1mm ² and about 200mm ², Optionally between about 1mm ² and about 167mm ², optionally between about 50mm ² and about 167mm ², Optionally between about 50mm ² and about 103mm ², optionally between about 35mm ² and about 100mm ². The cross-sectional area a ₂ of the bypass restrictor 130 can be any other value or range of values related to the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112 described herein.

In some constructions, the inner cross-sectional area a ₃、A₄ of each of the first and second nasal delivery elements 111, 112 is at the smallest lateral dimension of the respective nasal delivery element.

In some constructions, the inner cross-sectional area of each of the first and second nasal delivery elements 111, 112 is located at the outlet 111a, 112a of the respective nasal delivery element 111, 112. Or the internal cross-sectional area may be elsewhere; for example, midway along the nasal delivery elements 111, 112 or at the entrance or base of the nasal delivery elements.

The inner cross-sectional area a ₃、A₄ of each nasal delivery element 111, 112 may be in a direction transverse to the direction of gas flow through the nasal delivery elements 111, 112.

In some constructions, the bypass restrictor 130 includes at least one protrusion 130a, 130b that extends into the gas flow channel 125. In some constructions, the bypass restrictor 130 includes a plurality of protrusions that extend into the gas flow channel 125.

In some constructions, the gas manifold 120 includes proximal bypass protrusions 130a proximal to the nasal delivery elements 111, 112 and/or distal bypass protrusions 130b distal to the nasal delivery elements 111, 112.

In some configurations, the gas manifold 120 includes both a proximal bypass protrusion 130a and a distal bypass protrusion 130b, which in combination define a predetermined bypass dimension BD for restricted gas flow through the gas manifold 120 between the first and second nasal delivery elements 111, 112. In some configurations, the predetermined bypass dimension BD may be limited relative to an adjacent portion of the gas flow channel 125, relative to the gas inlet 121, relative to the combined cross-sectional area a ₃+A₄ of the first and second nasal delivery elements 111, 112, and/or relative to any other portion of the nasal interface 100.

In some configurations, the bypass restrictor 130 includes sloped leading edges 130a ', 130b' and sloped trailing edges 130a ", 130b" that define converging and diverging bypass restrictors in the direction of gas flow through the gas manifold from the first nasal delivery element 111 to the second nasal delivery element 112.

In some constructions, the gas manifold 120 includes a single inlet and a single outlet.

In some constructions, the nasal interface 100 includes an interface body 110 and a gas manifold component, and the interface body 110 and the gas manifold component together form the gas manifold 120.

In some constructions, the portion of the gas flow passage providing the cross-sectional area a ₂ is provided by the interface body 110 and the gas manifold component.

As described above, the interface body 110 may be formed of a soft, flexible material.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel can be variable. For example, when the patient wears the nasal interface 100, a portion of the patient's face may impinge on the base of the nasal delivery elements 111, 112 or the interface body 110 to narrow the bypass restrictor 130 and thus the cross-sectional area a ₂ of the portion of the gas flow path. This may be affected by the distance of the base of the nasal delivery elements 111, 112 from the patient's nasal septum. In some constructions, the interface body 110, or a portion thereof, may be configured to limit the variation in the cross-sectional area a ₂ of the portion of the gas flow path when the nasal interface 100 is worn by a patient. For example, a portion of interface body 110 may be reinforced with another more rigid material, reinforced with a more rigid material, and/or designed to have a particular geometry.

In some constructions, the gas manifold 120 or gas manifold component may be separate from the interface body 110.

In some constructions, the gas inlet 121 is located on one side of the gas manifold 120.

In some constructions, the nasal interface 100 includes a bias flow restrictor 140 for allowing gas to flow out of the nasal interface 100 through the bias flow restrictor 140.

In some constructions, the bias flow restrictor 140 includes at least one aperture 142 for allowing gas to flow from the nasal interface 100 to the surrounding environment. In some constructions, the bias flow restrictor 140 includes a plurality of apertures 142 for allowing gas to flow from the nasal interface 100 to the ambient environment.

In some constructions, the flow diverter 140 includes a filter or diffuser to filter or diffuse the gas flowing through the apertures 142.

In some constructions, the nasal interface includes a filter unit 500' between the gas manifold 120 and the bias flow restrictor 140.

In some configurations, the bias flow restrictor 140 is in fluid communication with the gas manifold 120. In some configurations, the gas manifold 120 includes a bias flow restrictor 140 or is coupled to a bias flow restrictor 140. In some configurations, the bias flow restrictor 140 is in fluid communication with the gas manifold 120, but is positioned remotely from the gas manifold.

In some constructions, the flow-deflecting restrictor 140 includes an open area for gas to flow out of the nasal interface 100 through the flow-deflecting restrictor 140. In some constructions, the opening area is greater than 0mm ² to about 40mm ², optionally between about 2mm ² and about 40mm ², optionally between about 2mm ² and about 5mm ², optionally between about 12mm ² and about 40mm ², optionally between about 20mm ² and about 30mm ².

In some constructions, the open area for gas to flow out of the nasal interface 100 through the bias flow restrictor is about 1mm ², about 2mm ², about 3mm ², about 4mm ², About 5mm ², about 6mm ², about 7mm ², about 8mm ², about 9mm ², About 10mm ², about 11mm ², about 12mm ², about 13mm ², about 14mm ², About 15mm ², about 16mm ², about 17mm ², about 18mm ², about 19mm ², About 20mm ², about 21mm ², about 22mm ², about 23mm ², about 24mm ², About 25mm ², about 26mm ², about 27mm ², about 28mm ², about 29mm ², About 30mm ², about 31mm ², about 32mm ², about 33mm ², about 34mm ², About 35mm ², about 36mm ², about 37mm ², about 38mm ², about 39mm ², Or about 40mm ², or a value between any two of these values.

For a given pressure differential between the body airflow passage 146 and the exterior of the flow diverter 140, the airflow through the flow diverter 140 is primarily determined by the cross-sectional area of the aperture 142 and its geometry. The geometric factor may be referred to as a flow coefficient. For example, a cylindrical outlet orifice 142 with sharp edges will pass less flow than a smooth orifice shaped like a venturi nozzle or an orifice with a substantial radius, chamfer or other expansion and contraction features on the inlet or outlet side. The viscous effect (e.g., in an elongated flow channel) can also reduce the total flow through the orifice, depending on the orifice shape.

The size of the aperture 140 may be increased, but the design of the filter or diffuser may additionally or alternatively be adjusted to add resistance.

Thus, if a properly configured filter or diffuser is used, the upper limit of the size range of the opening area for gas to flow out of the nasal interface 100 through the bias flow restrictor 140 may be increased by up to 25% (e.g., 50mm ² instead of 40mm ²).

Similarly, if holes 142 with high flow coefficients are used, the lower limit of the size range of the opening area for the airflow may be reduced by up to 50% (e.g., 6mm ² instead of 12mm ²).

In some configurations, the flow diverter 140 is configured such that when a pressure of greater than 0cmH ₂ O up to about 30cmH ₂ O is provided to the gas inlet 121 in use, the flow of gas stream exiting the nasal interface 100 through the flow diverter 140 is from greater than 0lpm to about 80lpm.

In some constructions, the bias flow restrictor 140 is configured such that the flow of gas out of the nasal interface 100 through the bias flow restrictor 140 is about 5lpm, about 10lpm, about 15lpm, about 20lpm, about 35lpm, about 40lpm, about 45lpm, about 50lpm, about 55lpm, about 60lpm, about 65lpm, about 70lpm, about 75lpm, about 80lpm, or any value between any two of these values when, in use, a pressure of about 5cmH ₂ O, about 10cmH ₂ O, about 15cmH ₂ O, about 20cmH ₂ O, about 25cmH ₂ O, about 30cmH ₂ O, or any value between any two of these values is provided to the gas inlet 121.

In some configurations, the bias flow restrictor 140 is configured such that the flow of gas out of the nasal interface 100 through the bias flow restrictor 140 is between about 35lpm and about 55lpm when, in use, a pressure of between about 5cmH ₂ O and about 10cmH ₂ O is applied to the gas inlet 121 and the nasal delivery elements 111, 112 are occluded.

In some configurations, the flow-bias restrictor 140 is configured such that the flow of gas out of the nasal interface 100 through the flow-bias restrictor 140 is between about 4lpm and about 15lpm when, in use, a pressure of between about 3cmH ₂ O and about 10cmH ₂ O is provided to the gas inlet 121 and the nasal delivery elements 111, 112 are occluded.

In some constructions, the bias flow restrictor 140 is configured such that the flow of gas flowing from the nasal interface 100 through the bias flow restrictor 140 is about 5lpm, about 6lpm, about 7lpm, about 8lpm, about 12lpm, about 13lpm, about 14lpm, about 15lpm, or any value between any two of these values when, in use, a pressure of about 3cmH ₂ O, about 4cmH ₂ O, about 5cmH ₂ O, about 6cmH ₂ O, about 7cmH ₂ O, about 8cmH ₂ O, about 9cmH ₂ O, about 10cmH ₂ O, or any value between any two of these values is provided to the gas inlet 121 and the nasal delivery elements 111, 112 are blocked.

In some configurations, the flow-bias restrictor 140 is configured such that the flow of gas out of the nasal interface 100 through the flow-bias restrictor 140 is between about 15lpm and about 80lpm when, in use, a pressure of between about 4cmH ₂ O and about 30cmH ₂ O is provided to the gas inlet 121 and the nasal delivery elements 111, 112 are occluded.

In some constructions, the bias flow restrictor 140 is configured such that the flow of gas out of the nasal interface 100 through the bias flow restrictor 140 is about 15lpm, about 20lpm, about 25lpm, about 40lpm, about 45lpm, about 50lpm, about 55lpm, about 60lpm, about 65lpm, about 70lpm, about 75lpm, about 80lpm, or any value between any two of these values when, in use, a pressure of about 5cmH ₂ O, about 10cmH ₂ O, about 15cmH ₂ O, about 20cmH ₂ O, about 25cmH ₂ O, about 30cmH ₂ O, or any value between any two of these values is provided to the gas inlet 121 and the nasal delivery elements 111, 112 are blocked.

In some constructions, the nasal interface 100 may be connected to an expiratory limb of a ventilator or have a Positive End Expiratory Pressure (PEEP) valve in addition to or instead of having a bias flow restrictor to control the amount of bias flow out of the nasal interface 100 that can affect pressure and flushing at the nasal interface 100.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is transverse to the direction of gas flow through the portion of the gas flow channel 125.

The inner cross-sectional area a ₃+A₄ of each nasal delivery element 111, 112 may be the cross-sectional area defined by the inner walls of the nasal delivery elements 111, 112. For non-circular cross-sections, the diameters mentioned herein can be interpreted as transverse dimensions. In some constructions, the diameters referred to herein include, but are not limited to, hydraulic diameters.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is reduced compared to the cross-sectional area a ₁ of the adjacent portion of the gas flow channel 125.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is between about 10% and up to about 100% of the first cross-sectional area a ₁ of the adjacent portion of the gas flow channel, optionally more than about 10% and less than 100% of the first cross-sectional area, optionally up to about 90% of the first cross-sectional area a ₁, optionally up to about 80% of the first cross-sectional area a ₁, optionally up to about 70% of the first cross-sectional area a ₁, optionally up to about 60% of the first cross-sectional area a ₁, optionally up to about 55% of the first cross-sectional area a ₁, optionally up to about 40% of the first cross-sectional area a ₁, optionally up to about 30% of the first cross-sectional area a ₁, and optionally up to about 25% of the first cross-sectional area a ₁.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel is up to about 300mm ², optionally up to about 280mm ², optionally up to about 270mm ², optionally up to about 200mm ², optionally up to about 160mm ², optionally up to about 110mm ², optionally up to about 80mm ², optionally up to about 60mm ², and optionally up to about 50mm ².

In some constructions, the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112 is greater than 0mm ² and up to about 250mm ², optionally between about 1mm ² and about 250mm ², optionally between about 1.6mm ² and about 250mm ², optionally between about 50mm ² and about 250mm ², optionally between about 50mm ² and about 200mm ², optionally between about 30mm ² and about 200mm ², optionally between about 30mm ² and up to about 155mm ², and optionally between about 50mm ² and up to about 155mm ².

In some constructions, the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112 is about 1mm ², about 1.6mm ², about 5mm ², about 10mm ², about 15mm ², about 20mm ², about 25mm ², about 30mm ², About 35mm ², about 40mm ², about 45mm ², about 50mm ², about 55mm ², About 60mm ², about 65mm ², about 70mm ², about 75mm ², about 80mm ², About 85mm ², about 90mm ², about 95mm ², about 100mm ², about 105mm ², about 110mm ², about 115mm ², about 120mm ², About 125mm ², about 130mm ², about 135mm ², about 140mm ², About 145mm ², about 150mm ², about 155mm ², about 160mm ², About 165mm ², about 170mm ², about 175mm ², about 180mm ², about 185mm ², about 190mm ², about 195mm ², about 200mm ², About 205mm ², about 210mm ², about 215mm ², about 220mm ², About 225mm ², about 230mm ², about 235mm ², about 240mm ², About 245mm ², about 250mm ², or any value between any two of these values.

In some configurations, the bypass restrictor 130 provides a pressure drop between the first and second nasal delivery elements 111, 112 through the nasal interface 100 when gas is delivered from the gas inlet 121 to the first and second nasal delivery elements 111, 112 such that the pressure at the first nasal delivery element 111 is higher than the pressure at the second nasal delivery element 112.

In some constructions, the nasal interface 100 of the present disclosure includes: a first nasal delivery element 111 and a second nasal delivery element 112, wherein the first nasal delivery element 111 and the second nasal delivery element 112 are each configured to seal with a respective nostril of a patient; and a gas manifold 120 comprising a gas inlet 121 and a gas flow channel for delivering respiratory gas to the gas manifold 120, wherein the first nasal delivery element 111 and the second nasal delivery element 112 are in fluid communication with the gas inlet 121 through the gas flow channel 125, wherein the first nasal delivery element 111 is proximal to the gas inlet 121 and the second nasal delivery element 112 is distal to the gas inlet 121, wherein the nasal interface comprises a bypass restrictor 130 providing a cross-sectional area a ₂ of a portion of the gas flow channel, wherein the first nasal delivery element 111 and the second nasal delivery element 112 each comprise an internal cross-sectional area a ₃、A₄, and wherein the internal cross-sectional area a ₃、A₄ of the nasal delivery elements and the cross-sectional area a ₂ of the portion of the gas flow channel are related to create, in use, an asymmetric gas flow of the nasal delivery elements 111, 112.

In some constructions, the internal cross-sectional areas a ₃、A₄ together provide a combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and wherein the cross-sectional area a ₂ of the portion of the gas flow passage 125 is greater than 0 to about 1.5 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel is up to about 1.3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, alternatively up to about 1 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, alternatively up to about 2/3 of the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, alternatively up to about 1/2 of the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, alternatively up to about 2/5 of the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, alternatively up to about 1/3 of the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112.

In some constructions, the inner cross-sectional area a ₃、A₄ of each of the first and second nasal delivery elements 111,112 is at the smallest lateral dimension of the respective nasal delivery element 111, 112.

In some constructions, the inner cross-sectional area a ₃、A₄ of each of the first and second nasal delivery elements 111,112 is located at the outlet 111a,112a of the respective nasal delivery element 111, 112. Or the internal cross-sectional area may be elsewhere; for example, midway along the nasal delivery elements or at the entrance or base of the nasal delivery elements 111, 112.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 1, optionally up to about 2/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and the nasal interface is configured to provide 20lpm of bias flow through the bias flow restrictor 140 when a pressure of 4cmH ₂ O is provided to the gas inlet 121 and the nasal delivery elements 111, 112 are blocked. This may be, for example, in an adult respiratory mode patient with 15 Breaths Per Minute (BPM) of 10i:20e 500 vt.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 1, optionally up to about 2/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and the nasal interface is configured to provide 32lpm of bias flow through the bias flow restrictor 140 when pressure of 8cmH ₂ O is provided to the gas inlet 121 and the nasal delivery elements 111, 112 are blocked. This may be, for example, in a patient with an adult respiratory pattern of 15BPM with 10i:20e 500 Vt.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 2/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and the nasal interface is configured to provide a bias flow of 20lpm through the bias flow restrictor 140 when a pressure of 4cmH ₂ O is provided to the gas inlet 121 and the nasal delivery elements 111, 112 are blocked (this may be, for example, in a 15BPM adult respiratory mode patient having 10i:20e 500vt, or in a 15BPM adult respiratory mode patient having ARDS and 25 BPM), or configured to provide a bias flow of 32lpm through the bias flow restrictor 140 when a pressure of 8cmH ₂ O is provided to the gas inlet 121 and the nasal delivery elements 111, 112 are blocked, or configured to provide a bias flow of 41lpm through the bias flow restrictor 140 when a pressure of 12cmH ₂ O is applied to the gas inlet 121 and the nasal delivery elements 111, 112 are blocked, or configured to provide a bias flow of 16cmH ₂ O pressure is applied to the gas inlet 121 and the nasal delivery elements 111, 112 are blocked, or configured to provide a flow restrictor 48lpm through the bias flow restrictor 140 when a pressure of 48lpm is applied to the nasal delivery elements 111, 112 are blocked and the bias flow restrictor 53 is provided to the nasal delivery element, 4 is blocked. This may be for example in patients with ARDS and with an adult breathing pattern of 25 BPM.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 2/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and the nasal interface is configured to provide a bias flow through the bias flow restrictor 140 of 32lpm or more when a pressure of 8cmH ₂ O is provided to the gas inlet 121 and the nasal delivery elements 111, 112 are blocked. This may be, for example, in a patient with 15BPM of 10i:20e 500vt in an adult respiratory mode, or in a patient with ARDS and with 25BPM in an adult respiratory mode, or in a patient with 25BPM in a 350 sinusoidal respiratory mode.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 1/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111,112 and the nasal interface is configured to provide a bias flow through the bias flow restrictor 140 of 32lpm or more when a pressure of 8cmH ₂ O is provided to the gas inlet 121 and the nasal delivery elements 111,112 are blocked, or wherein the cross-sectional area a ₂ of the portion of the gas flow channel is up to about 2/5 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111,112 and the nasal interface is configured to provide a bias flow through the bias flow restrictor 140 of 41lpm or more when a pressure of 12cm H ₂ O is provided to the gas inlet 121 and the nasal delivery elements 111,112 are blocked, or wherein the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 2/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111,112 and the nasal interface is configured to provide a bias flow through the bias flow restrictor 140 of 16cm H ₂ O pressure to the gas inlet 121 and the nasal delivery elements 111,112 are blocked.

The effectiveness of the asymmetric airflow (and the resulting flushing) of the nasal interface 100 was evaluated for six different ratios in three different tests.

Each test includes a set breathing pattern, the setting of the CPAP varying in accordance with the set breathing pattern. Tables 2 and 3 show the constant and varying settings of the test, respectively. The test results are shown in fig. 23 to 25.

TABLE 2

TABLE 3 Table 3

In each of the tables above xi: ye is the ratio of x inspiration time to y expiration time, vt is the tidal volume, and the amount of air (in ml) that moves into or out of the lungs per respiratory cycle is measured.

In each test, asymmetric airflow and flushing were measured by re-inhalation (the lower the re-inhalation, the greater the flushing). A typical level of re-inhalation in CPAP without asymmetric airflow is about 60ml. Thus, for the purposes of these tests, flushing may be understood as being equal to "60mL-x", where x = re-inhaled volume in mL, 60mL being an example value of the upper airway model, excluding the mouthpiece itself, and assuming no dead space in the mouthpiece.

As shown in fig. 23-25, effective flushing is achieved at approximately 102:154 (about 2/3) and lower ratios (bypass restrictor cross-sectional area (braj): combined nasal delivery element cross-sectional area (CNDEA)).

Tests at a ratio of 1:1 (BRA: CNDEA) and above showed inconsistent and/or minimal flushing. However, some flushing was shown/expected at ratios as high as 1.5:1 (BRA: CNEDA). In practice, the ratio selected may be lower than 1:1 (BRA: CNDEA).

Test 1 (15 bpm;4,8cmH ₂ O) showed significant flushing at 102:154 (about 2/3) (BRA: CNEDA) and lower, inconsistent flushing at 1:1 (BRA: CNDEA), and minimal flushing at 200:154 (about 1.5) (BRA: CNDEA).

Test 2 (25 bpm;4,8, 12, 16, 20cmH ₂ O) showed significant flushing at 102:154 (about 2/3) (BRA: CNDEA) and lower, but minimal flushing at 1:1 (BRA: CNDEA) and higher.

Test 3 (45 bpm;4,8, 12, 16, 20cmH ₂ O) showed flushing at the higher cmH ₂ O level at 102:154 (about 2/3) (BRA: CNDEA) and lower, except that no significant flushing was observed.

More particularly, referring to FIG. 23, in test 1, significant flushing was achieved at a ratio of 102:154 (about 2/3) (BRA: CNDEA) and lower. A1:1 ratio (BRA: CNEDA) showed effective flushing at 8cmH ₂ O, but minimal flushing at 4cmH ₂ O. Minimal flushing is achieved at 200:154 (about 1.5) (BRA: CNDEA).

Referring to fig. 24, in test 2, significant flushing was achieved at a ratio of 102:154 (about 2/3) (BRA: CNDEA) and lower (except at 4cmH ₂ O102:154 BRA: cndea). Minimal flushing was shown at 4, 8 and 12cmH ₂ O levels for ratios of 1:1 (BRA: CNDEA) and higher. Those ratios were not tested at 16cmH ₂ O and 20cmH ₂ O levels.

At low pressure and high respiratory rates, rebreathing can occur due to insufficient bias current. This may affect the results, especially at low pressures, because the bias current increases at higher pressures.

Referring to FIG. 25, in test 3, for higher cmH ₂ O levels, significant flushing was achieved at 102:154 (about 2/3) (BRA: CNDEA) and lower rates, but not at lower cmH ₂ O levels. Flushing better than baseline is achieved under the following conditions: 8cmH ₂ O and above (BRA: CNDEA) for 50:154 (about 1/3), 12cmH ₂ O and above (BRA: CNDEA) for 60:154 (about 2/5), and 16cmH ₂ O and above (BRA: CNDEA) for 75:154 (about 1/2) and 102:154 (about 2/3). In this test, no flushing was achieved at a ratio of 1:1 (BRA: CNDEA) or higher.

Figures 26-28 show the simulated effects of different nasal delivery element 111, 112 sizes, different bypass restrictor cross-sectional areas, different set pressures, and different bias flow restrictor openings on re-inhalation with the nasal interface, 15 breaths per minute, 25 breaths per minute, and 45 breaths per minute, respectively.

The Y-axis (slave axis) on the graph shows re-inhalation, where lower amounts are better and represent more irrigation.

The "nasal delivery element size" of each figure represents the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112.

A is less than B. a-B provides a range of possible combined cross-sectional areas a ₃+A₄.

In some constructions, as described herein, the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112 is greater than 0mm ² (a) and up to about 250mm ² (B), optionally between about 1mm ² and about 250mm ², optionally between about 1.6mm ² and about 250mm ², optionally between about 50mm ² and about 250mm ², Optionally between about 50mm ² and about 200mm ², optionally between about 30mm ² and about 200mm ², Optionally between about 30mm ² and about 155mm ², optionally between about 50mm ² and about 155mm ², And optionally between about 70mm ² and about 155mm ².

The "bypass restrictor size" section of each figure shows the cross-sectional area a ₂ of the bypass restrictor 130, i.e., the cross-sectional area a ₂ of the portion of the gas flow path.

C is less than D. C-D provides a possible range of bypass restrictor cross-sectional areas A ₂.

As described herein, in some constructions, the bypass restrictor 130 cross-sectional area a ₂ is greater than 0 to about 1.5 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, optionally about 0.25 to about 1.5 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, optionally about 1 times or less the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, optionally about 2/3 times or less the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112.

In some constructions, as described herein, the bypass restrictor 130 has a cross-sectional area a ₂ that is greater than 0mm ² (C) and up to about 375mm ² (D), optionally between about 1mm ² and about 375mm ², Optionally between about 1mm ² and about 250mm ², optionally between about 1mm ² and about 200mm ², Optionally between about 1mm ² and about 167mm ², optionally between about 50mm ² and about 167mm ², Optionally between about 50mm ² and about 103mm ², optionally between about 35mm ² and about 100mm ², And optionally about 65mm ². The cross-sectional area a ₂ of the bypass restrictor 130 can be any other value or range of values related to the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112 described herein.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel is greater than 0 to about 1.5 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112 is between about 1mm ² and about 250mm ².

The "set pressure" portion of each figure shows the pressure applied to the gas inlet 121 of the nasal interface 100.

E is less than F. E-F provides a possible range of pressures applied to the gas inlet 121.

As described herein, in some configurations, a pressure greater than 0cmH ₂ O (E) and up to about 30cmH ₂ O (F) is provided to the gas inlet 121 in use.

In some configurations, a pressure of between about 3cmH ₂ O to about 10cmH ₂ O is provided to the gas inlet 121 in use.

In some configurations, a pressure between about 4cm H ₂ O and about 30cm H ₂ O is applied to the gas inlet 121 in use.

The "bias flow" portion of each figure shows the effect of the opening of the open area for gas exiting the nasal interface 100 through the bias flow restrictor 140 on re-inhalation and irrigation. "Filter-less" means a more open bypass restrictor in which no filter or diffuser is placed. "with filter" shows a more closed bypass restrictor with a filter or diffuser placed over the bypass restrictor.

As described above, in some constructions, the flow-deflecting restrictor 140 includes an open area for the flow of gas out of the nasal interface 100 through the flow-deflecting restrictor 140. In some constructions, the opening area is greater than 0mm ² to about 40mm ², optionally between about 2mm ² and about 40mm ², optionally between about 2mm ² and about 5mm ², optionally between about 12mm ² and about 40mm ², optionally between about 20mm ² and about 30mm ².

In some constructions, the bias flow restrictor 140 is configured such that the flow of gas out of the nasal interface through the bias flow restrictor is from greater than 0lpm to about 80lpm when, in use, a pressure of between greater than 0cmH ₂ O and up to about 30cmH ₂ O is provided to the gas inlet 121.

In some constructions, the flow-bias restrictor 140 is configured such that the flow of gas out of the nasal interface through the flow-bias restrictor is between about 4lpm and about 15lpm when, in use, a pressure of between about 3cmH ₂ O and about 10cmH ₂ O is provided to the gas inlet 121.

In some constructions, the flow-bias restrictor 140 is configured such that the flow of gas out of the nasal interface through the flow-bias restrictor is between about 15lpm and about 80lpm when, in use, a pressure of between about 4cmH ₂ O and about 30cmH ₂ O is provided to the gas inlet 121.

These curves show that at lower respiratory rates (e.g., 15BPM and 25 BPM), increasing the combined cross-sectional area of the nasal delivery element, decreasing the bypass restrictor cross-sectional area, increasing the pressure applied to the gas inlet, and/or increasing the open area for gas flow through the bias flow restrictor 140 can reduce the re-inhalation volume and increase the irrigation volume.

The combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112 can be maximized to increase irrigation, sized to fit comfortably in the patient's nostrils.

The cross-sectional area a ₂ of the bypass restrictor 130 may be minimized to increase flushing, although increasing this cross-sectional area may increase patient comfort.

These curves show that at higher respiratory rates (e.g., 45 BPM), changing the nasal delivery element cross-sectional area or bypass restrictor can have a negligible effect due to re-inhalation in the gas conduit (thus the left two boxes in the 45BPM curve are shaded gray because they are statistically insignificant to the results). Increasing the pressure applied to the gas inlet 121 and/or increasing the open area for gas to flow through the bias flow restrictor 140 reduces the re-breathe and increases the flush volume.

Headgear may be used to hold the nasal interface 100 on the patient's face. The headgear includes a headband 200. The headgear 200 may be a single continuous length and adapted to extend along the patient's cheeks, over the ears, and around the back of the head in use, may be adjustable, and/or may extend around other portions of the patient's head.

The end of the headgear is connected to the side arms of the interface body 110.

In the exemplary configuration shown (fig. 18), the primary ends 201 and 202 of the strap 200 are adapted to be releasably connected to the respective structures 101 and 102 on either side of the nasal interface 100 to hold the nasal interface 100 in place during use.

In one configuration, a clip member is provided at each end 201, 202 that is capable of being received and retained within the respective structure 101, 102. The clip member may be coupled to the strap at each primary end. In addition, the headband 200 is adjustable in length to help customize the band to fit the wearer's head. The belt 200 may be formed of a soft and stretchable/elastic material that is comfortable to the wearer, such as an elastic textile material/fabric. Or the band 200 may be formed of a substantially more rigid or less flexible material, such as a hard plastic material.

The headgear may also include additional straps or other headgear components to couple the strap 200 to extend atop the patient's head in use. The overhead strap or overhead component may have the benefit of pulling the strap 200 upward over the patient's ear in use to improve fit and comfort.

The rear portion of the strap 200 may extend through the receiver 204. The receiver 204 may allow for adjustment of the rear of the band 200 to adjust the headgear size to fit the patient's head.

The fixed length belt segments may be releasably connected to the main belt to extend its length.

A plurality of belt segments of different predetermined lengths may be provided to provide selectable adjustment lengths. For example, one or more belt segments may be provided having a length in the range of about 1cm to about 10cm, or a length in the range of about 2cm to about 6 cm. The belt segment 220 has a length, for example, of about 2cm, about 4cm, or about 6 cm. It should be appreciated that these examples are not limiting, as the length of each band segment may be any size, as this depends on the user and/or application.

Furthermore, each end of each belt segment may be connected to a respective end of another belt segment and/or may be connected to a respective secondary end of primary belt 210, thereby enabling a user to combine one or more belt segments of the same or different lengths to customize the overall length of the extension as desired.

The additional belt segments may be formed of a soft and stretchable/elastic material, such as an elastic textile material/fabric, that is comfortable to the wearer. For example, a tubular knitted headband or section of headband 210 may be used, particularly for comfort over the user's ears.

It should be appreciated that particular comfort may be achieved by a headgear that is capable of properly positioning the nasal interface 100 in a relatively stable position on the user's face while also allowing a relatively loose fit or low tension fit around the user's head.

Or the additional band segments may be formed of a substantially rigid material, such as a hard plastic material.

Interface connectors 240 are provided at the primary ends 201 and 202 of the main belt 210. These connectors 240 have a strap connection mechanism to connect the primary ends 201, 202, but include clip members (such as push-fit clips 241) at the ends of the connectors 240 opposite the strap ends. Clip 241 is configured to releasably couple corresponding formations 101, 102 of the sides of nasal interface 100. The clip member 241 may be a bendable portion, such as a plastic portion, that forms a hinge with respect to the strap. The clip 241 may be preformed to have a curved shape along its length. In one example, clip 241 may be preformed with two or more portions angled relative to each other, such as an angle between 0 degrees and 20 degrees. The curvature and/or angle allows clip 241 to fit the contours of the non-patient's face in the region of clip 241.

The nasal interface may include a sleeve 270. Each sleeve 270 may be preformed to have a curved shape along its length, for example, having a curved shape with an angle between a flat 20 degrees. The curved shape allows the sleeve to fit, in use, the contours of the patient's face or cheek in the region of the sleeve. Or the sleeve 270 may take on a curved sleeve shape when engaged with the primary ends 201, 202 of the headband 200 or the connector 240.

The sleeve 270 provides a surface area of relatively high friction surface material for frictional engagement with the face or facial skin of a user. The surface area is positioned for frictional engagement with the user's facial cheek skin. The surface area is at least localized to the band or band segment to be positioned on the user's cheek. The surface area with a relatively high friction surface material may be a material that feels smooth and comfortable on the patient's skin. Thus, the sleeve 270, or at least the surface region 271, is formed of a relatively softer material than the connector 240.

In one configuration, the surface region 271 or sleeve 270 is formed of a soft thermoplastic elastomer (TPE), but may alternatively be formed of another plastic material, such as silicone, or any other biocompatible material.

The surface area 271 may be a surface having a wider surface area that is more proximate to the patient interface than a surface area that is more distant from the patient interface. In one configuration, the sleeve 270 tapers from a relatively wider surface area 273 to a relatively smaller surface area 274 in a direction extending away from the connection point between the connector 240 and the nasal interface 100. The width of the sleeve at end 273 may be the same as or similar to the width of the tapered distal ends of the corresponding wings 113, 114 of the face-mount component 110. This provides a smooth transition between the nasal interface 100 and the headgear to improve aesthetics and achieve a visually attractive effect.

The sleeve 270 may be colored to provide identification of the nasal interface 100. As described herein, the nasal interfaces may be provided in different sizes, such as small, medium, and large. Each of these sized sleeves 270 may include a different color to represent a different size. Alternatively or additionally, the sleeve may be colored in a particular manner to indicate that the nasal interface has an asymmetric nasal delivery element instead of a symmetric nasal delivery element.

The headgear may include cheek support members 270 as described or similar at the two side ends of the headgear straps connected to the nasal interface at or adjacent the interface for frictional engagement with the user's face to stabilize the mask cheek on the face. Such headgear may also include a single headband adapted to extend in use along the patient's cheeks, over the ears, and around the back of the head, the ends including any suitable form of clip that is coupled to both sides of (or permanently attached to) the nasal interface.

The patient interface 1 may include a tube retaining clip (not shown). The tube retaining clip may support a respiratory conduit 300 or other gas supply tube 16 from a portion of the patient interface 1. By supporting the respiratory conduit 300 or other gas supply tube from or near the nasal interface 100, bending moments exerted on the respiratory conduit 300 or other gas supply tube 16 due to asymmetric gas flow through the first and second nasal delivery elements 111, 112 and/or patient head movement will be resisted by the tube retaining clip, thereby improving patient comfort.

The patient interface 1 may have any one or more of the features and functions described in PCT publication WO 2014/182179 or U.S. patent 10,406,311. The contents of these specifications are incorporated herein by reference in their entirety.

As an alternative to headgear, the patient interface may comprise a fixation system of the type described in PCT publication WO 2012/053910 or us patent 10,238,828. The contents of these specifications are incorporated herein by reference in their entirety.

Fig. 29 schematically shows an alternative configuration of a nasal interface 1100 for use in the patient interface 1. The features, functions, alternatives, and uses of the nasal interface 1100 are the same as those described for the nasal interface 100, unless otherwise described below. Like reference numerals refer to like parts, except that 1000 is added. An exemplary configuration of the nasal interface is described in more detail below with reference to fig. 30-59.

The nasal interface 1100 includes an interface body 1110 configured to substantially form a seal with the patient's nasal airway. The interface body 1110 is configured to deliver gas to a first naris of a patient and a second naris of the patient.

The nasal interface 1100 includes a gas inlet 1121 for delivering breathing gas into the nasal interface 1100. The gas inlet 1121 is in fluid communication with the interface body 1110 to, in use, deliver breathing gas from the gas inlet 1121 through the interface body 1110 to the first naris and the second naris of the patient.

The nasal interface 1100 is configured to receive an inlet gas F0 from the gas inlet 1121 and provide a first flow F1 of gas from the inlet gas F0 that is configured to be substantially provided to a first naris of a patient in use and a second flow F2 of gas that is configured to be substantially provided to a second naris of the patient in use.

The nasal interface 1100 is configured to direct more of the incoming gas to the first flow F1 than to the second flow F2 to create an asymmetric flow of gas at the patient's nasal airway throughout the patient's respiratory cycle.

The flow rate generated by respiratory therapy depends on the flow rate through nasal interface 1100. The flow through the nasal interface 1100 is related to the pressure at each outlet 1111a, 1112a of the nasal interface. If the pressure at each outlet 1111a, 1112a is different, an asymmetric airflow will be created.

The nasal interface may include outlets 1111a, 1112a that are distinct from each other for delivering breathing gas to each naris of the patient. Or the nasal interface may include a single outlet defining first and second outlets for delivering respiratory gases to respective nostrils of the patient. Thus, references herein to "a first outlet" and "a second outlet" may alternatively be considered to refer to "a first outlet" and "a second outlet", respectively. Some possible exemplary configurations are described in more detail below.

The nasal interface 1100 provides an asymmetric airflow by directing more airflow to the first naris/first outlet 1111a than the second naris/second outlet 1112 a. This may be considered as flow directionality.

The nasal interface 1100 may be constructed and arranged to provide directionality of flow in a variety of different ways. For example, the nasal interface 1100 may include a flow directing portion and/or a flow dividing portion and/or a gas inlet at least partially aligned with the first outlet 1111a to provide flow directionality. Some possible exemplary configurations are described in more detail below.

In some constructions, the nasal interface 1100 can include an interface body 1110 and a gas manifold 1120.

The interface body 1110 and the gas manifold 1120 can cooperate to define a gas chamber 1115 therein. In some alternative constructions, the gas chamber 1115 may instead be substantially or solely defined by the interface body 1110. Instead of having a gas manifold 1120, the nasal interface 1100 may include a frame member to support the interface body and/or one or more other components (e.g., the gas inlet 1121, headgear 200, and/or interface body 1110). Thus, references herein to a "gas manifold" may alternatively be considered to refer to a "frame".

The interface body 1110 may be configured to contact and seal inside the patient's nostrils, may be configured to contact and seal at the entrance to the patient's nostrils, and/or may be configured to seal around the outer surface of the nose (e.g., the wings and tip of the nose).

In some configurations, the interface body 1110 includes a first outlet 1111a configured to substantially deliver gas to a first naris of a patient and a second outlet 1111b configured to substantially deliver gas to a second naris of the patient.

In some constructions, the interface body 1110 includes first and second nasal delivery elements 1111, 1112 configured for engagement with respective nostrils of a patient.

In some constructions, the interface body 1110 is a nasal cushion. The nasal cushion may include a single outlet providing the first outlet portion and the second outlet portion. Or the nasal cushion may include first and second nasal delivery elements 1111, 1112, each configured to engage a respective nostril of the patient.

The nasal interface 1110 is constructed and arranged to produce an asymmetric flow of gas at the patient's nasal airway throughout the patient's respiratory cycle.

In the configuration shown in fig. 29, the gas inlet 1121 is at least partially aligned with the first outlet 1111a and less or not aligned with the second outlet 1112 a.

This configuration directs the gas flow from the gas inlet 1121 to the first outlet 1111a. This configuration may provide a substantially direct gas flow from the gas inlet 1121 to the first outlet 1111a. The alignment of the gas inlet 1121 with the first outlet 1111a may serve as a flow guide.

The flow path for the gas flow from the gas inlet 1121 to the second outlet 1112a is more tortuous than the flow path for the gas flow from the gas inlet 1121 to the first outlet 1111 a. Additionally or alternatively, the flow path of the gas flow from the gas inlet 1121 to the second outlet 1112a may be longer than the flow path for the gas flow from the gas inlet 1121 to the first outlet 1111 a.

The gas inlet 1121 is offset from the central axis C-A of the nasal interface 1100.

In some constructions, the gas inlet 1121 is substantially axially aligned with the first outlet 1111 a.

In some constructions, at least half of the cross-sectional area A0 of the gas inlet 1121 is axially aligned with at least half of the cross-sectional area A1 of the first outlet 1111 a.

The gas inlet includes an outer portion 1121a connected to a breathing conduit 300 or other gas supply tube 16 for providing a flow of gas from the gas source to the interface body 1110, and also includes an inner portion 1121b in fluid communication with the interface body 1110.

The inner portion 1121b of the gas inlet 1121 is at least partially aligned with the first outlet 1111a or the first outlet portion.

The inner and outer portions 1121b, 1121a may be aligned with each other or may be inclined relative to each other.

In some constructions, the first outlet 1111a and the second outlet 1112a comprise substantially the same cross-sectional area. That is, the airflow asymmetry is caused by other features in the nasal interface 1100 rather than the different outlet sizes.

In some constructions, the first outlet 1111a and the second outlet 1112a may be symmetrical and structurally identical.

In some configurations, nasal interface 1100 is configured to deliver a lower flow rate of air through first outlet 1111a than through second outlet 1112a during the inspiratory phase of the respiratory cycle.

Because of the less restricted flow path to the first outlet 1111a, the first airflow F1 has a lower flow rate and a higher pressure than the second airflow F2 along the more restricted flow path to the second outlet 1112 a.

The nasal interface 1100 may include a flow restrictor that restricts the flow of air to the second outlet 1112 a. The flow restrictor may be provided by one or more of a flow directing portion, a flow diverting portion, or any other suitable feature. The restriction may include a bypass restriction.

In some constructions, the nasal interface 1100 is configured to deliver a higher pressure of the airflow through the first outlet 1111a than the second outlet 1112a during the inspiratory phase of the respiratory cycle.

In the configuration shown in fig. 29, the interface body 1110 comprises a first nasal delivery element 1111 comprising a first outlet 1111a and a second nasal delivery element 1112 comprising a second outlet 1112a, wherein the nasal interface 1100 is configured such that the first airflow F1 is configured to be substantially delivered to the first nasal delivery element 1111 and the second airflow F2 is configured to be substantially delivered to the second nasal delivery element 1112, and wherein both the first nasal delivery element and the second nasal delivery element are configured to seal with respective nostrils of a patient.

In some constructions, the nasal interface includes a deflector configured to direct more of the incoming gas F0 from the gas inlet 1121 to the first gas flow F1 than to the second gas flow F2.

Fig. 29 shows a first exemplary configuration of the flow guide. In this configuration, the flow guide includes an inner portion 1121a of the gas inlet 1121. Because the gas inlet is more aligned with the first outlet 1111a than the second outlet 1112a, the flow guide directs more of the incoming gas F0 to the first gas flow F1 than the second gas flow F2.

In some constructions, and as described below, the nasal interface includes a connector or elbow for connecting the respiratory conduit 300 to the patient interface.

The connector or elbow may include a flow guide or may be a flow guide. That is, the connector or elbow may be a component that directs the airflow more toward the first outlet 1111a than toward the second outlet 1112 a.

In some configurations, the nasal interface 1100 is configured to direct more of the incoming gas to the first gas flow F1 than the second gas flow F2 during the inspiratory phase of the respiratory cycle. In addition, this may also occur during the expiratory phase of the respiratory cycle. The inspiratory phase and the expiratory phase may define a respiratory cycle.

In some configurations, the flow path F1 to the first naris includes a converging flow path. Additionally or alternatively, the flow path F2 to the second naris includes a divergent flow path.

In some constructions, the flow guide includes a nozzle configured to accelerate the airflow toward the first outlet 1111 a.

In such a configuration, a first portion of the nozzle proximate to the gas inlet 1121 or proximate to the inlet 1121a into the gas inlet may have a relatively larger cross-sectional dimension, and a second portion of the nozzle distal to the gas inlet 1121 or distal to the inlet 1121a into the gas inlet (and proximate to the interface body 1110 and/or the gas chamber in the gas manifold 1120) may have a relatively smaller cross-sectional dimension. Due to the decrease in cross-sectional area, the nozzle will accelerate the gas through the nozzle towards the first outlet 1111 a.

In some configurations, the decrease in cross-sectional area of the nozzle may be a gradual decrease, e.g., a taper, in cross-sectional area between the first and second portions of the nozzle. In another configuration, the decrease in cross-sectional area of the nozzle may be one or more substantially abrupt decreases in cross-sectional area between the first and second portions of the nozzle, such as one or more step changes.

The nozzle may include a portion of the gas inlet 1121, or may be coupled or in fluid communication with the gas inlet 1121. In some constructions, the nozzle can include an insert received in the gas inlet 1121.

The nozzles are configured to increase the flow rate of gas into the gas flow passages 1125, thereby increasing the dynamic pressure of one naris compared to the other naris.

Fig. 85 (a) - (c) illustrate three exemplary configurations of nozzles N1-N3 that may be used with any of the nasal interfaces described herein.

In nozzle N1 of fig. 85 (a), the cross-sectional area of the nozzle decreases along the nozzle length and then expands again toward the nozzle outlet. The reduction and/or expansion of the cross-sectional area may be gradual as shown, or may include a plurality of steps.

In nozzle N2 of fig. 85 (b), the cross-sectional area of the nozzle decreases gradually along the nozzle length from the nozzle inlet to the nozzle outlet. The decrease in cross-sectional area may be gradual as shown, or may include a plurality of steps.

In nozzle N3 of fig. 85 (c), the nozzle has a substantially constant cross-section along substantially the entire length of the nozzle, but the cross-sectional area of the nozzle outlet NO of the nozzle is much smaller than the rest of the nozzle, which means that the air flow needs to accelerate through the nozzle outlet NO.

Table 4 shows an exemplary relationship between the cross-sectional area of the inlet 1121a into the gas inlet and the minimum cross-sectional area of the nozzle.

TABLE 4 Table 4

In some configurations, the minimum nozzle area may be about 0.1 times the inlet area or greater, alternatively about 0.2 times the inlet area or greater.

Preferably, there may be a larger minimum nozzle area to reduce flow resistance; however, having too much airflow can affect dynamic pressure in the nasal interface and at the nostrils. The nozzle can balance these requirements.

In alternative constructions, the gas inlet 1121 may include a diffuser instead of a nozzle.

In some constructions, the nozzle may be provided in combination with additional flow directors. Or the nozzle may be used as a deflector.

The nasal interface 1100 will be configured to deliver, in use, breathing gas from the gas inlet 1121 through the interface body 1110 to both the first nostril and the second nostril of the patient.

The nasal interface 1100 includes a bias flow restrictor 1140 that includes at least one aperture 1140a and optionally a plurality of apertures 1140a for the flow of gas from the nasal interface 1100 to the ambient environment.

The bias current limiter 1140 may provide the functionality described above for the bias current limiter 140.

During respiratory therapy, there will typically be a positive flow of air out of the patient interface 1100 through the bias flow restrictor 1140.

The flow diverter 1140 may include a filter and/or diffuser to filter or diffuse the gas flowing through the holes 1140 a. When a filter is used, the filter may also function as a diffuser in some constructions.

In the illustrated construction, a bias flow restrictor 1140 is provided in the gas manifold 1120.

In some configurations, the bias flow restrictor is positioned closer to the second nasal delivery element 1112 and the second outlet 1112a than the first nasal delivery element 1111 and the first outlet 1111a. This facilitates the flow of exhaled gases through the second nasal delivery element 1112 and out of the nasal interface through the bias flow restrictor 1140.

The bias flow restrictor 1140 may be located elsewhere than the gas manifold 1120.

When inlet gas is delivered to the nasal interface 1100 and the nasal interface is not mounted on the patient and the outlet has no flow restriction, there will be an asymmetric flow of gas through the first outlet 1111a and the second outlet 1112 a. The pressure at the outlets 1111a, 1111b may be checked to determine if an asymmetric airflow is present.

The nasal interface 1100 is configured to provide a greater dynamic pressure at a first nostril of a patient during use and a lesser dynamic pressure at a second nostril of the patient during use.

Accordingly, the nasal interface 1100 may be considered to include an interface body 1110 configured to substantially form a seal with a patient's nasal airway, the interface body 1110 configured to deliver gas to a patient's first nostril and a patient's second nostril.

The nasal interface 1100 comprises a gas inlet 1121 for delivering respiratory gas into the nasal interface, wherein the gas inlet 1121 is in fluid communication with the interface body 1110 for delivering, in use, respiratory gas from the gas inlet 1121 through the interface body 1110 to the first and second nostrils of the patient.

The nasal interface 1100 is configured to provide a greater dynamic pressure at a first naris of a patient during use and a lesser dynamic pressure at a second naris of the patient during use. The greater dynamic pressure at the first naris of the patient compared to the lesser dynamic pressure at the second naris of the patient during use creates an asymmetric airflow at the nasal airway of the patient. An asymmetric flow of gas may be generated at the patient's nasal airway during the inspiratory phase of the respiratory cycle. In addition, this may also occur during the expiratory phase of the respiratory cycle. The inspiratory phase and the expiratory phase may define a respiratory cycle. In this way, an asymmetric flow of air may be provided at the patient's nasal airway through the nasal interface 1100 throughout the patient's respiratory cycle.

The nasal interface 1100 provides an asymmetric airflow. In the use of a nasal interface, when delivering flow or pressure therapy to a patient, such as CPAP or BiPAP, there is a net flow from the first naris of the patient to the second naris of the patient throughout the respiratory cycle.

In some configurations, the patient may breathe spontaneously.

The respiratory cycle may be described as having an inspiratory phase, a transition phase (which phase may also be referred to as a screen phase) in which the patient neither inhales nor exhales, and an expiratory phase. The turning phase may occur in a much shorter period of time than the inhalation phase and/or the exhalation phase.

A flow of gas delivered by the breathing assistance device at a total pressure enters the nasal interface 1100 from the gas inlet 1121. The gas flow has a static pressure component and a dynamic pressure component, wherein the dynamic pressure component refers to a flow component.

The flow of gas from the gas inlet is split in the nasal interface and the resulting first flow F1 (which may have a larger cross-sectional area (referred to herein as a-1)) is directed toward the first naris, while the second flow F2 (which may have a smaller cross-sectional area (referred to herein as a-2)) is directed toward the second naris and the bias flow restrictor 1140.

Such a split may create a bias flow towards the first naris.

In some configurations, area A-1 is greater than area A-2, and the pressure drop or restriction of airflow through area A-2 is greater than the pressure drop or restriction through area A-1.

In some configurations, the area A-1 is greater than the area A-2 and a majority of the airflow is directed in the direction of the first naris.

In some configurations, the area A-1 may not be greater than the area A-2, but the incoming airflow may be directed more toward the first naris than toward the second naris, and/or the flow path of the second airflow F2 to the second naris may be more tortuous than the flow path of the first airflow F1 to the first naris.

In these configurations, at least a portion of the area A-2 may include a filter or diffuser to filter or diffuse the gas flowing through the second gas flow F2 to the second naris. A filter or diffuser provided in at least a portion of the area a-2 may be used to create a bias flow toward the first naris.

The bias flow to the first naris results in a greater dynamic pressure at the first naris than at the second naris. The dynamic pressure is the flow component of the total pressure because the airflow enters with its energy directed in the direction of the first naris.

During the inspiratory phase of respiration, the airflow from the gas inlet 1121 enters the two nostrils in different proportions, wherein more airflow enters the first nostril than the second nostril due to the bias flow created as described above. Air flow that does not enter the first naris and/or the second naris may flow from the patient interface to atmosphere through the bias flow restrictor 1140. In some configurations, airflow may leave the second naris during some or all of the inhalation, rather than enter the second naris. Such gas flow may be part of the gas flow from the gas inlet 1121, or the gas flow exiting the patient's airway via the second naris, or a combination thereof.

During the breath-hold phase, the flow of gas from the gas inlet 1121 is split in the nasal interface, and some of the split enters the first naris and exits the second naris through the patient's airway. The flow of gas from the split flow (or portions thereof) and/or exiting the patient's airway via the first naris and/or the second naris exits to atmosphere via the bias flow restrictor 1140.

During the expiratory phase of respiration, the airflow either exits both nostrils or may enter the first nostril and exit the second nostril depending on the configuration of flow out through the bias flow restrictor 1140. Some of the gas flow may flow back through the nasal interface to the gas inlet 1121. If the airflow exits the first naris, the incoming gas stagnates and flows through the gas chamber 1115 to the second naris along with the airflow from the first naris, and out to the atmosphere via the bias flow restrictor 1140. Since the total pressure at the second naris is less than the total pressure at the first naris, airflow will flow out of the second naris if there is a net flow out of the lungs.

The nasal interface provides a pressure differential between the flow path of the first airflow F1 and the flow path of the second airflow F2.

In at least some configurations, the breathing gases from the gas inlet 1121 are more accessible to the first naris because they are directed toward the first naris and there is resistance to movement toward the second naris (e.g., in the form of a tortuous flow path and/or a reduced flow path). The second airflow F2 needs to be routed back or through a flow restrictor into the second naris, but the first airflow F1 does not need to do so, resulting in more gas flowing to the first naris. Similarly, at the second naris, as the exhaled gas from the patient is directed toward the bias flow restrictor 1140, the exhaled gas is more readily expelled through the second naris and there is resistance to movement back toward the first naris (again through tortuous and/or restricted flow paths). Thus, there is a dynamic pressure differential in both directions (into the first naris, and out of the second naris).

The nasal interface 1100 has a single gas inlet 1121. Thus, the first and second outlets 1111a, 1112a or the first and second outlets receive respective gas flows from the breathing gas from the inlet.

The nasal interface 1100 may be used with a single gas source, such as a single gas flow generator.

An exemplary configuration of a nasal interface that provides the nasal interface function of fig. 29 will be described below with reference to fig. 30-59. Unless described differently below, the features, functions, alternatives, and uses of the nasal interface are the same as described for nasal interface 1100 or for any other nasal interface. For each exemplary configuration, the same reference numerals, to which 100 is added, denote the same components.

Fig. 30-36 illustrate an exemplary configuration of a nasal interface 1200.

The nasal interface 1200 includes an interface body 1210 and a gas manifold 1220.

The gas manifold 1220 and interface body 1210 are coupled together to define a gas chamber 1215 therein. The gas chamber 1215 provides fluid communication between the gas inlet 1221 and the first and second outlets 1211a, 1212 a.

The nasal interface 1200 includes a bias flow restrictor 1240 that includes at least one aperture for allowing airflow from the nasal interface 1100 to the surrounding environment.

The bias flow restrictor 1240 is at least partially aligned with the second outlet 1212a and less or not aligned with the first outlet 1211 a.

In the illustrated configuration, the flow diverter is substantially axially aligned with the second outlet 1212 a.

The gas inlet 1221 is provided as part of or coupled to a connector or elbow 1222 for connecting the respiratory conduit 300 to the patient interface 1200.

Connectors or elbows 1222 enter the gas manifold 1220 from the front of the gas manifold. Or the connector or elbow 1222 may enter the gas manifold 1220 from a different location; such as to the side of the gas manifold 1220 or below the gas manifold.

The nasal interface 1200 includes connector portions 1213, 1214 for connecting the headgear 200 to the gas manifold 1220 and/or interface body 1210.

As shown in fig. 31, the incoming airflow F0 is split into two airflows F1, F2 along respective flow paths, each leading to a respective outlet 1211a,1212a and a respective naris.

As shown in fig. 31, the first air flow F1 has at least one dimension D1 that is greater than the corresponding dimension D2 of the second air flow F2. The same applies to other configurations of the nasal septum described herein.

The at least one dimension D1 may comprise a lateral dimension of the first air flow F1, and the corresponding dimension D2 may comprise a lateral dimension of the second air flow F2.

For example, the diameter, cross-sectional area, and/or volume of the first air flow F1 may be greater than the corresponding diameter, cross-sectional area, and/or volume of the second air flow F2.

In some configurations, the ratio of the cross-sectional area of the first air flow F1 (in the direction of dimension D1) to the corresponding cross-sectional area of the second air flow F2 (in the direction of dimension D2) is between about 2:1 and about 5:1, alternatively between about 2:1 and about 4:1, alternatively between about 2.5:1 and about 3.5:1, alternatively about 3:1.

In some configurations, the ratio of the cross-sectional area of the first gas flow F1 to the corresponding cross-sectional area of the second gas flow F2 is about 2:1, 2.25:1, 2.5:1, 2.75:1, 3:1, 3.25:1, 3.5:1, 3.75:1, 4:1, 4.25:1, 4.5:1, 4.75:1, 5:1, or any value between any two of these values.

For example only, the combined cross-sectional area of the first and second gas flows F1, F2 at or near the gas inlet 1221 may be about 200mm ², the cross-sectional area of the first gas flow F1 may be about 150mm ², and the cross-sectional area of the second gas flow F2 may be about 50mm ².

Although the above relationship of the at least one dimension D1 of the first air flow F1 and the corresponding dimension D2 of the second air flow F2 is described with respect to the configuration of fig. 30-36, the same relationship may be used for any of the configurations of fig. 29-59.

The airflow relationship may be slightly different between inhalation and exhalation and/or may be slightly different when the airflow generator delivers different pressures/flows.

In some constructions, the nasal interface 1200 is configured to provide less asymmetry during the inspiratory phase of the respiratory cycle and more asymmetry during the expiratory phase of the respiratory cycle, but is configured to provide asymmetric airflow throughout the respiratory cycle. That is, the pressure difference of the air flow flowing through the first outlet 1121a and the second outlet 1221b is higher during the exhalation phase than during the inhalation phase.

Due to the directing of the air flow, more air flow is provided to the first outlet 1211a and less air flow is provided to the second outlet 1212a.

As such, the first nasal delivery element 1211 and the first outlet 1211a have a higher pressure than the second nasal delivery element 1212 and the second outlet 1212 a.

This creates a pressure differential between the nostrils to provide an asymmetric flow of gas at the patient's airway.

When there is more airflow into one naris (the first naris associated with the first outlet 1211 a) than into the other naris (the second naris associated with the second outlet 1212 a), this means that the other naris may be used for exhalation. This is graphically represented in fig. 32, showing the main flow of breathing gas EF. The naris associated with the first outlet 1212a may also exhale, but the flow stream from that naris will travel a longer and more tortuous flow path towards the bias flow restrictor 1240.

This may flush out dead space as airflow primarily enters the first naris and exits the other naris.

As described elsewhere herein, the nasal interface may be used with pressure controlled therapy (i.e., CPAP, biPAP). The asymmetric airflow in the nasal interface is a result of the pressure differential.

In the case of a nasal interface, if one nostril is fully occluded, pressure controlled therapy (i.e., CPAP, biPAP) may be provided at the unplugged nostril without asymmetry. The work of re-inhalation can be increased. The nasal interface provides this function by not directing 100% of the incoming airflow to one naris by default.

In the illustrated construction, the nasal interface 1200 has two baffle features. Different configurations of the nasal interface 1200 may have a single one of the two baffle features or both baffle features.

The first flow director feature is that the gas inlet 1221 is positioned more toward the first outlet 1211a than the second outlet 1212b, as described above with respect to fig. 29.

The second baffle feature includes a flow splitting section 1230 configured to split the flow F0 from the gas inlet 1221 unequally into a first flow F1 configured to be substantially provided to a first naris of a patient in use and a second flow F2 configured to be substantially provided to a second naris of the patient in use. The first airflow F1 is configured such that the airflow delivered along the first airflow F1 is greater than the airflow delivered along the second airflow F2 to create an asymmetric airflow at the patient's airway in use.

In some constructions, the nasal interface 1200 includes: an interface body 1210 configured to substantially form a seal with a patient's nasal airway, the interface body 1210 configured to deliver gas to a patient's first nostril and a patient's second nostril; and a gas inlet 1221 for delivering respiratory gases into the nasal interface, wherein the gas inlet 1221 is in fluid communication with the interface body 1210 to deliver, in use, respiratory gases from the gas inlet 1221 through the interface body 1210 to the first and second nostrils of the patient; and a flow splitting section 1230 configured to split the flow from the gas inlet 1221 unequally into a first flow F1 and a second flow F2, the first flow F1 configured to be substantially provided to the first naris of the patient in use, the second flow F2 configured to be substantially provided to the second naris of the patient in use, wherein the first flow F1 is configured to deliver a greater flow along the first flow F1 than along the second flow F2 to create an asymmetric flow at the nasal airway of the patient throughout the respiratory cycle of the patient.

In some constructions, the nasal interface 1200 includes: interface body 1210 comprising a first nasal delivery element 1211 and a second nasal delivery element 1212, the first nasal delivery element 1211 comprising a first outlet 1211a configured to deliver gas to a first nostril of a patient, the second nasal delivery element 1212 comprising a second outlet 1212a configured to deliver gas to a second nostril of the patient, wherein each of the first nasal delivery element 1211 and the second nasal delivery element 1212 are configured to seal with the respective nostril of the patient; and a gas inlet 1221 for delivering respiratory gases into the nasal interface 1200, wherein the gas inlet 1221 is in fluid communication with the interface body 1210 to deliver respiratory gases from the gas inlet 1221 through the first nasal delivery element 1211 and through the second nasal delivery element 1212; and a flow splitting section 1230 for unequally splitting the flow of gas from the gas inlet 1221 into a first flow of gas F1 configured to be substantially provided to the first nasal delivery element 1211 and a second flow of gas F2 configured to be substantially provided to the second nasal delivery element 1212, wherein the first flow of gas F1 is configured to deliver a greater flow of gas along the first flow of gas F1 than the second flow of gas F2 to create an asymmetric flow of gas at the nasal airways of the patient throughout the respiratory cycle of the patient.

The shunt 1230 may be disposed in the interface body 1210, the gas manifold 1220, and/or the gas inlet 1221. The gas inlet 1221 may be part of the elbow/connector 1222 or may be a separate component.

The shunt portion 1230 may be integrally formed with one or more of these components, or may be separately formed and connected to one or more of these components.

The shunt 1230 may be a removable insert arranged to connect to one or more of these components. The removable insert may be used to convert an existing nasal interface to an asymmetric nasal interface.

In the illustrated construction, the flow split 1230 includes a wall portion that extends toward or into the gas inlet 1221, with the first gas flow F1 on one side of the wall portion and the second gas flow F2 on the other side of the wall portion.

In some constructions, the split 1230 extends into the gas inlet and splits the gas inlet 1221 into a first gas flow portion on one first side of the split 1230 and a second gas flow portion on the other side of the split 1230.

For example, as shown in fig. 31-34 and 35 and 36, the shunt portion 1230 may include a cylindrical wall that is aligned with the first outlet 1211a and extends in a direction away from the first outlet 1211a (and toward or into the gas inlet 1221). Alternatively, the diverging portion 1230 may have a different configuration. For example, the shunt 1230 may include a wall (flat or otherwise) between the first nasal delivery element 1211 and the second nasal delivery element 1212.

The flow dividing portion 1230 may be a substantially rigid portion to provide a substantially constant relationship between the first air flow F1 and the second air flow F2.

In some configurations, the nasal interface may include a flow guide configured to direct more of the incoming gas from the gas inlet 1221 to the first gas flow F1 than the second gas flow F2. A flow guide portion may be provided in addition to the flow dividing portion 1230.

In some constructions, the flow guide may include a nozzle configured to accelerate the airflow toward the first outlet 1221.

As shown in fig. 32, the body portion 1210 is provided with coupling features 1210a for engagement with complementary coupling features 1220a on the gas manifold 1220.

In the illustrated construction, the coupling feature 1210a includes an inwardly opening recess, and the complementary coupling feature 1220a includes a radially outwardly extending flange received in the recess. Alternatively, the coupling feature 1210a may comprise a radially inward flange and the complementary coupling feature may comprise an outwardly opening recess.

In the illustrated construction, the interface body 1210 is a nasal cushion.

The nose pad is made of one or more compliant materials, such as thermoplastic elastomers, latex, vinyl, silicone, or polyurethane.

Still referring to fig. 32, in some constructions, the inner portion 1210b of the nose pad that is configured to contact the user's face is more flexible than the outer portion 1210c of the nose pad that is not configured to contact the user's face. The outer portion 1210c is more rigid or stiff than the more flexible or pliable inner portion 1210 b. The inner portion 1210b includes first and second nasal delivery elements 1211, 1212 and/or first and second outlets 1211, 1212.

The more rigid outer portion 1210c supports the overall shape of the nose pad. The more flexible inner portion 1210b enhances sealing against the patient's face and also enhances patient comfort.

In the illustrated construction, at least a portion of the more rigid outer portion 1210c has a thicker wall than the more flexible inner portion 1210 b. Additionally or alternatively, the more rigid outer portion 1210c may include one or more features to enhance rigidity, such as one or more ribs.

The nasal cushion and nasal interface may have any one or more of the features described in U.S. patent 10,792,451 or U.S. patent application publication 2020/0046928. The contents of these specifications are incorporated herein by reference in their entirety.

Fig. 37 illustrates another exemplary configuration of a nasal interface 1300.

In this configuration, the manifold 1330 is disposed in the interface body 1310 and the gas manifold 1320.

The manifold includes a first manifold portion 1330a in the interface body 1310 and a second manifold portion 1330b in the gas manifold 1320.

The first diverter portion 1330a includes a wall portion that extends toward or into the gas inlet 1321. The second branch portion 1330b includes a wall in the gas inlet 1321.

The second divider section 1330b divides the gas inlet 1321 into a first gas flow portion on one side of the second divider section 1330b and a second gas flow portion on the other side of the second divider section 1330 b.

The first and second branch portions 1330a and 1330b are configured to be immediately adjacent to each other and may contact each other or at least partially overlap.

The first air flow F1 is located at one side of the first and second branch portions 1330a and 1330b, and the second air flow F2 is located at the other side of the first and second branch portions 1330a and 1330 b.

Fig. 38 shows another exemplary configuration of a nasal interface 1400.

This configuration uses gas inlet alignment and a tortuous flow path to create an asymmetric flow of gas at the patient's nasal airway throughout the patient's respiratory cycle.

In this configuration, the gas inlet 1421 is substantially aligned with the first outlet 1411a or the first outlet. This provides a substantially direct flow path for the first gas flow F1 to the first outlet 1411 a.

The flow divider 1430 provides a restricted tortuous flow path (indicated in fig. 38 by the arrow near reference numeral 1415) for the second air flow F2 to the second outlet 1412 a.

The tortuous flow path increases the flow rate and thus reduces the pressure at the second outlet 1412 a.

Fig. 39 and 40 illustrate another exemplary configuration of a nasal interface 1500.

This configuration uses gas inlet alignment and tortuous flow paths to create an asymmetric gas flow at the patient's nasal airway. An asymmetric flow of gas may be generated at the patient's nasal airway during the inspiratory phase of the respiratory cycle. In addition, this may also occur during the expiratory phase of the respiratory cycle. The inspiratory phase and the expiratory phase may define a respiratory cycle. In this way, an asymmetric flow of air may be provided at the patient's nasal airway through the nasal interface 1100 throughout the patient's respiratory cycle.

In this configuration, the gas inlet 1521 is substantially aligned with the first outlet 1511a or the first outlet portion. This provides a substantially direct flow path for the first gas flow F1 to the first outlet 1511 a.

A flow restrictor 1530 is provided in the gas chamber 1515, formed between the gas manifold 1520 and the interface body 1510.

The flow restrictor provides a restricted tortuous flow path for the second air flow F2 to the second outlet 1512 a.

The tortuous flow path increases the flow rate and thus reduces the pressure at the second outlet 1512 a.

Fig. 41 illustrates another exemplary configuration of a nasal interface 1600.

In this configuration, the gas inlet 1621 enters the gas manifold 1620 from the side rather than from the front.

The gas inlet 1621 includes an outer portion 1621a connected to the respiratory conduit 300 for providing a flow of a gas source to the interface body 1610, and further includes an inner portion 1621b in fluid communication with the interface body.

The inner portion 1621b of the gas inlet 1621 is at least partially aligned with the first outlet 1611 or the first outlet portion.

The gas inlet 1621 includes a change in direction between an outer portion 1621a and an inner portion 1621 b.

The direction change may be any suitable angle. In some constructions, the direction change may be between about 30 degrees and about 100 degrees, alternatively between about 45 degrees and about 100 degrees, alternatively between about 60 degrees and about 100 degrees, and alternatively about 90 degrees.

Likewise, the nasal interface 1600 provides a restricted tortuous flow path for the second airflow F2.

Fig. 42 shows another exemplary configuration of a nasal interface 1700.

The shunt portion 1730 of this configuration is similar to the shunt portion of fig. 37.

This configuration differs in that the gas inlet 1721 enters the nasal interface more centrally than is aligned with the first outlet 1711 a. That is, the axis along the center of the gas inlet will be relatively centered between the axes extending through the outlets 1711a, 1712 a.

In some constructions, the gas inlet 1721 is centrally located on the nasal interface.

In the configuration of fig. 42, the shunt 1730 alone may provide flow directionality.

Fig. 43 illustrates another exemplary configuration of a nasal interface 1800.

In this configuration, the gas inlet 1821 is offset with respect to, but inclined toward, the first outlet 1811a or the first outlet portion. This directs the airflow more toward the first outlet 1811a or the first outlet portion than toward the second outlet 1812a or the second outlet portion.

Due to the inclination of the gas inlet 1821, an axis A-A extending through the gas inlet 1821 is at A non-parallel angle with respect to A central axis C-A through the nasal interface 1800.

The angle will depend on the offset between the gas inlet 1821 and the first outlet 1811a into the gas manifold 1820.

In some constructions, the angle is greater than 0 degrees and up to about 30 degrees, alternatively up to about 20 degrees, alternatively up to about 15 degrees, and alternatively up to about 10 degrees.

The angled gas inlet 1821 configuration may be used in a nasal interface in which the gas inlet is centered, or in a nasal interface in which the gas inlet is offset toward the first outlet 1811a or the first outlet portion.

The angled gas inlet 1821 configuration may be the only feature of the nasal interface 1800 that directs the flow of gas toward the first outlet 1811a or the first outlet portion. Alternatively, the nasal interface 1800 may have one or more of the other flow directing features described herein, such as a shunt portion.

Fig. 44 illustrates another exemplary configuration of a nasal interface 1800.

In this configuration, the interface body 1910 is a nose pad.

To properly seal with the patient's face and provide a comfortable experience for the patient, the nasal cushion is flexible and designed to compress/deform against the patient's face. The nose pad may compress/deform in multiple directions when positioned on and in contact with the face.

The nasal cushion includes a shunt 1930. The shunt 1930 in this configuration is configured to move and/or deform as the nasal cushion compresses.

Compression/deformation of the nasal cushion may cause the ratio or proportion of diversion or diversion to vary from patient to patient, depending on the compression/deflection level of the nasal cushion.

The shape of the flow dividing portion may be changed by movement and/or deformation of the flow dividing portion 1930, resulting in a change in the ratio between the first air flow F1 and the second air flow F2.

The shunt 1930 may be flexible and may be configured to deform when the nose pad is compressed/deformed. Alternatively, the flow divider 1930 may be more rigid.

In the illustrated construction, the flow diversion portion 1930 is configured to move more toward or into the gas inlet 1921 as the nasal cushion compresses/deforms, as shown in fig. 44 (b). This may result in more airflow being directed along the first airflow F1 than the second airflow F2 than in the rest position of the nasal cushion (shown in fig. 44 (a)).

Fig. 45 and 46 illustrate alternative exemplary configurations of nasal cushion 2010 that may be used as an interface body in any of the nasal interfaces disclosed herein.

In this configuration, the nasal cushion 2010 includes a single outlet for delivering gas to both the first and second nostrils of the patient. The single outlet includes a first outlet 2011a 'and a second outlet 2012a'. The nasal cushion 2010 and thus the nasal interface are configured such that the first airflow F1 is configured to be delivered substantially to the first outlet portion 2011a 'and the second airflow F2 is configured to be delivered substantially to the second outlet portion 2012a'.

In the illustrated construction, the nasal cushion 2010 includes a shunt portion 2030 having a first wall portion 2030a and a second wall portion 2030 b. The first wall portion 2030a and the second wall portion 2030b are hingedly connected to each other. The relative angles of the first and second wall portions 2030a, 2030b are configured to change as the nasal cushion 2010 is deformed/compressed.

The deformation of the shunt portion 2030 may be configured to maintain a substantially constant ratio between the first airflow F1 and the second airflow F2 as the nasal cushion 2010 is deformed or compressed. Or deformation of the shunt portion 2030 may be configured to change the ratio between the first airflow F1 and the second airflow F2 when the nasal cushion 2010 is deformed or compressed.

Fig. 47 and 48 illustrate an exemplary deformation of the shunt portion 2030 as the nasal cushion 2010 is compressed.

As shown in these figures, in some constructions, the peripheral wall 2030c opposite the first wall 2030a and the second wall 2030b may also deform as the nasal cushion 2010 is deformed/compressed.

Fig. 49 shows an alternative exemplary configuration of a nasal cushion 2110 that may be used as an interface body in any of the nasal interfaces disclosed herein.

In this configuration, the diverting portion 2130 again includes a first wall portion 2130a and a second wall portion 2130b.

The first wall portion 2130a and the second wall portion 2130b overlap each other in a relaxed state of the nose pad 2110. The degree of overlap of the wall portions 2130a, 2130b increases as the nose pad 2110 compresses.

The configurations of fig. 47-49 may be used in a nasal cushion or interface body having first and second nasal delivery elements with respective outlets rather than a single outlet having first and second outlets.

As described above, any of the nasal interfaces disclosed herein may use a nasal cushion having a single outlet for delivering gas to both the first and second nostrils of the patient. The single outlet includes a first outlet portion and a second outlet portion. A single outlet may have no obvious septum breach between the nostrils, which may be more comfortable for the patient by having no septum contact.

In this configuration, diversion/diversion will occur before the outlet section. Fig. 50 illustrates three exemplary configurations of such nasal cushions 2210, 2310, 2410, wherein flow directing features or splits 2330, 2430 are provided by gas manifold portions 2220, 2320, 2420.

Or the flow directing feature may be provided by a nasal cushion, such as the configuration of fig. 45-48.

In an alternative configuration, the nose pad may have a septum contact portion. An exemplary configuration of such a nose pad 2510 is shown in fig. 51.

The diaphragm contact 2513 forms a first outlet 2511a and a second outlet 2512a for delivering gas to respective nostrils of a patient.

The septum contact 2513 may provide a greater split between the first and second airflows F1, F2 and reduce mixing of the first and second airflows before they are delivered through the first and second outlets 2511a, 2512 a.

Fig. 52 shows an alternative exemplary nasal cushion 2610.

The configuration includes short first and second nasal delivery elements 2611, 2612. The nasal delivery elements are shorter than those shown in the embodiment of fig. 31, for example.

By having a shorter nasal delivery element, the first and second openings 2611a, 2612a may be larger than would be the case with a longer nasal delivery element.

The nasal delivery elements 2611a, 2612a form a positioning feature to help position the nasal delivery elements 2611a, 2612a in the nostrils and may help keep the nostrils open.

Fig. 53-56 illustrate another exemplary configuration of a nasal interface 2700.

In this configuration, the deflector includes a gas inlet 2721 that is inclined toward the first outlet 2711 a. Which directs the airflow more toward the first outlet 2711a than toward the second outlet 2712 a.

The gas inlet 2721 includes a nozzle configured to accelerate the gas flow toward the first outlet 2711a or the first outlet portion.

In the illustrated construction, a first portion of the nozzle proximate the gas inlet 2721a has a relatively larger cross-sectional dimension D3 and a second portion of the nozzle distal from the inlet 2721a into the gas inlet (and proximate the interface body 2710 and/or the gas chamber 2715 in the gas manifold 2720) has a relatively smaller cross-sectional dimension. The nozzle will accelerate the gas through the nozzle towards the first outlet 2711a or the first outlet portion.

In some constructions, the outlet at the nozzle second portion has a cross-sectional area between about 15mm ² and about 150mm ².

The nozzle may include a portion of the gas inlet 2721, or may be coupled or in fluid communication with the gas inlet.

In the illustrated construction, the gas inlet 2721 is part of a connector or elbow 2722. Thus, the connector or elbow 2722 is configured to direct the airflow more toward the first outlet 2711a than toward the second outlet 2712 a.

The gas inlet 2721 and the connector or elbow 2722 may be integrally formed or may be coupled to each other.

In the illustrated construction, the nozzle acts as a deflector. In an alternative configuration, the nozzle may be provided in combination with an additional deflector. For example, the nozzle may be shorter than shown, and additional flow guides in the interface body 2710 and/or the gas manifold 2720 may direct the flow of gas from the nozzle more toward the first outlet 2711a or the first outlet portion than toward the second outlet 2712a or the second outlet portion.

The second air flow F2 has a more restricted tortuous flow path than the first air flow F1.

The bias flow restrictor may be provided at any suitable location on the nasal interface 2700.

In one configuration, a bias flow restrictor 2740' is provided in the interface body 2710/nose pad. In another alternative, a bias flow restrictor 2740 "may be provided in the gas manifold 2720.

Fig. 57-59 illustrate another exemplary configuration of a patient interface including a nasal interface 2800.

In this configuration, the diverter 2830 is disposed in the interface body 2810 and the gas manifold 2820.

The diverter includes a first diverter portion 2830a in the interface body 2810 and a second diverter portion 2830b in the gas manifold 2820.

The first diverter portion 2830a includes a wall portion extending toward or into the gas inlet 2821. The second flow divider section 2830b includes the walls of the gas inlet 2821.

The first diverter portion 2830a is received in the second diverter portion 2830b of the gas inlet 2821.

The first diverging portion 2830a diverges the gas flow F0 from the gas inlet into a first gas flow portion on one side of the first diverging portion 2830a and a second gas flow portion on the other side of the first diverging portion 2830 a.

The first and second diverter portions 2830a and 2830b are configured to be immediately adjacent to each other and to partially overlap.

A gap is provided between the outside of the first divider section 2830a and the inside of the second divider section. The gap provides a flow path for the second airflow F2 to travel over a restricted tortuous path for delivery to the second outlet 2812a or the second outlet portion.

In the illustrated construction, the bias flow restrictor 2840 includes an array of holes 2840a on the front of the gas manifold 2820.

In some constructions, the straps 210 'of the headgear 200' may be integrally formed with the gas manifold 2820. For example, the band 210' may be overmolded with the gas manifold 2820.

Fig. 60-64 illustrate another example structured patient interface including an example structured nasal interface 2900.

The patient interface includes a nasal interface 2900 that includes an interface body 2910 and a frame 2920. The patient interface also includes a headgear 200 to at least maintain the patient interface in position on the patient in use.

Interface body 2910 includes a nasal delivery element 2911 configured to seal with the nostrils of the patient. The interface body may include a single nasal delivery element 2911, or may include two nasal delivery elements 2911, 2912. When the interface body includes two nasal delivery elements 2911, 2912, the first nasal delivery element 2911 may be configured to seal with a respective nostril of the patient and the second nasal delivery element 2912 may be configured to seal with a respective nostril of the patient or alternatively may be configured not to seal with a respective nostril of the patient.

The nasal interface 2900 includes a gas inlet 2921 for delivering breathing gas into the nasal interface 2900. The gas inlet 2921 and the nasal delivery elements 2911, 2912 are in fluid communication with the gas flow channel 2925 or gas chamber of the interface body 2910 to deliver breathing gas from the gas inlet 2921 through the nasal delivery elements 2911, 2912.

In some constructions, the nasal interface 2900 includes an interface body 2910 and a frame 2920 or gas manifold that cooperate to define a gas flow channel 2925 therein. In some alternative constructions, the gas flow channel 2925 may instead be defined substantially or solely by the interface body 2910, and the frame 2920 or gas manifold may not be provided.

The gas inlet 2921 may be substantially centered on the nasal interface, or may be offset relative to a midline plane MP of the nasal interface, as described below with reference to fig. 75-77.

The gas inlet 2921 may include one or more engagement features 2921t for engaging with a breathing tube that delivers gas to the nasal interface 2900. For example, the gas inlet 2921 may include one or more external engagement features 2921t for engaging with a breathing tube. In some constructions, the one or more external engagement features 2921t include one or more threads. The threads may be continuous or discontinuous. Or the gas inlet 2921 may be friction fit with the breathing tube.

The gas inlet 2921 may have any suitable cross-sectional shape in a direction transverse to the flow of gas through the gas inlet. In some constructions, the gas inlet 2921 has a substantially circular cross-sectional shape. In an alternative configuration, the gas inlet 2921 has a non-circular cross-sectional shape. For example, the gas inlet 2921 may have a larger dimension in a direction across the nasal interface 2900 and a smaller dimension in a direction parallel to the sagittal plane of the patient in use. This configuration may reduce or avoid overlapping of the connected breathing tube ends above and below the central frame body portion 2920a of the frame 2920 without adversely reducing the flow of gas through the gas inlet 2921. The non-circular cross-sectional shape may be any suitable shape, such as elongated, oval or elliptical.

Interface body 2910 includes a softer material than frame 2920, which includes a more rigid material. Interface body 2910 is configured to be soft and conform to the patient's face, while frame 2920 is configured to be more rigid to provide support for interface body 2910. The frame may be semi-rigid or rigid.

Interface body 2910 may be formed of a soft, flexible material, such as silicone, thermoplastic elastomer, or other polymers known in the art. Nasal delivery elements 2911 and 2912 may be flexible and may be formed of a thin enough layer of silicone or other suitable material to achieve this characteristic. The interface body 2910 and the nasal delivery elements 2911, 2912 may be formed, for example, from an elastomeric material capable of conforming to the nostril and/or cheek geometry of a patient and providing an effective pneumatic seal.

Interface body 2910 may include molded components.

The frame 2920 may be formed of a more rigid material, such as nylon, polypropylene, polycarbonate, or other rigid or semi-rigid materials known in the art.

Headgear 200 may include one or more buckles 203 or other adjustment features to enable adjustment of the length of headgear strap 201.

As discussed further below, the front end 205 of the headgear strap may be configured to extend through the through-passages 2923a, 2924a of the side arms 2923, 2924 of the frame 2920 to attach the headgear 200 to the nasal interface 2900. The front end 205 may also provide some adjustment to the length of the headgear strap 201.

Headgear 200 may be formed from any suitable material. For example, headgear strap 201 may be formed from a fabric material, and buckle 202 may be formed from a polymer material.

Referring to fig. 61, 62, and 65-69, interface body 2910 includes first and second interface body side arms 2913, 2914. The interface body side arms 2913, 2914 form compliant cheeks for contacting the patient's cheeks in use.

In some constructions, the interface body side arms 2913, 2914 each include an unsealed lumen 2915 to enhance the flexibility of the interface body side arms 2913, 2914.

The slit 2915a may extend through at least one wall of the interface body side arms 2913, 2914.

The unsealed nature of the lumen 2915 means that air can freely flow into and out of the lumen 2915 as the side arms expand or compress, thereby enhancing flexibility and compliance of the cheek portions.

Each interface body side arm 2913, 2914 includes a patient proximal wall 2916 configured to contact the patient's cheek in use, and a patient distal wall 2917 configured to be spaced apart from the patient's cheek in use. The patient proximal wall 2916 is spaced apart from the patient distal wall 2917, with an unsealed lumen 2915 located between the patient proximal wall 2916 and the patient distal wall 2917.

The slit 2915a may be disposed in the patient distal wall 2917 such that the patient proximal wall may be a continuous surface to enhance patient comfort.

In some constructions, the interface body side arms 2913, 2914 are completely hollow. That is, there may be nothing inside the interface body side arms 2913, 2914 except for the unsealed lumen 2915. In alternative constructions, the cavity 2915 may be sealed. In alternative constructions, the interface body side arms 2913, 2914 may include or be filled with a thick soft material.

When an unsealed cavity 2915 is provided, it may assist in demolding interface body 2910.

The compliant cheek portion facilitates pressure distribution across the patient's face to help reduce or avoid undesirable pressure applied to the patient's nostrils by the nasal delivery element. The cheek portion may act as a nasal pillow to provide a range of patient sizes. This allows a significant amount of anterior-posterior movement to fit the patient's face while enabling the nasal delivery element to remain in contact with and/or seal against the patient's nostrils. The cheek portion can be used as a nasal pillow to distribute pressure over the patient's face.

The interface body side arms 2913, 2914 may have a contour shape that generally follows the shape of the patient's face.

In the illustrated construction, the interface body side arms 2913, 2914 each have a length (in the lateral direction of the nasal interface 2900) that is greater than the width. However, in alternative constructions, the length and width may be substantially the same, or the width may be greater than the length.

Interface body side arms 2913, 2914 may be integrally formed with the rest of interface body 2910, or may be formed separately from the rest of interface body 2910 and coupled to the rest of interface body 2910.

Referring to fig. 60-69, interface body 2900 includes a first interface body side arm 2913 and a second interface body side arm 2914. The frame 2920 includes first and second frame side arms 2923, 2924. The first and second interface body side arms 2913, 2914 each include a through passage 2913a, 2914a to enable a respective one of the first and second frame side arms 2923, 2924 to extend therethrough to couple the first and second frame side arms 2923, 2924 with the first and second interface body side arms 2913, 2914.

When the first and second frame side arms 2923, 2924 are coupled with the first and second interface body side arms 2913, 2914, the proximal portions 2913b, 2914b of the first and second interface body side arms 2913, 2914 are located behind the proximal portions 2923b, 2924b of the first and second frame side arms 2923, 2924 so as to be positioned, in use, between the patient's face and the proximal portions 2923b, 2924b of the first and second frame side arms 2923, 2924.

The proximal portions 2913b, 2914b of the first and second interface body side arms 2913, 2914 are side arm portions closer to the central interface body portion 2910 a. The proximal portions 2923b, 2924b of the first and second frame side arms 2923, 2924 are side arm portions that are closer to the central frame body portion 2920 a.

In some constructions, at least a majority of the length of the interface body side arms 2913, 2914 is located behind the proximal portions 2923b, 2924b of the first and second frame side arms 2923, 2924 in use.

Interface body 2910 includes a softer material than frame 2920, which includes a more rigid material.

The interface body side arms 2913, 2914 each include a respective compliant cheek. As described above, the compliant cheek portion may act as a nasal pillow to distribute pressure.

In some constructions, each through channel 2913a, 2914a is positioned adjacent to an outer end of a respective interface body side arm 2913, 2914. With this configuration, the amount of overlap between the interface body side arms 2913, 2914 and the frame side arms 2923, 2924 is maximized, which minimizes the amount of contact between the frame side arms 2923, 2924 and the patient's face in use. However, depending on the shape and thickness of the interface body side arms 2913, 2914, the through channels 2913a, 2914a may be positioned further inward toward the medial proximal ends of the interface body side arms 2913, 2914.

Each through channel 2913a, 2914a may include a hole or slit.

The frame side arms 2923, 2924 are configured to attach to the headgear 200.

The frame side arms 2923, 2924 include headgear attachment features 2923a, 2924a adjacent the outer ends of the frame side arms 2923, 2924. The headgear attachment features 2923a, 2924a include holes or slits to receive the front end 205 of the headgear strap, or may include any other suitable configuration, such as clips, fasteners, or the like.

In the illustrated construction, the interface body 2910 includes a central interface body portion 2910a, and the frame 2920 includes a central frame body portion 2920a. The central interface body portion 2910a and the central frame body portion 2920a are configured to be coupled together to define a gas flow channel 2925 for delivering respiratory gases from the gas inlet 2921 through the nasal delivery elements 2911, 2912. By engaging the frame side arms 2923, 2924 with the interface body side arms 2913, 2914 as described above, the central interface body portion 2910a and the central frame body portion 2920a are coupled together to form a gas flow channel.

When an unsealed lumen 2915 is disposed in the interface body side arms 2913, 2914, the slit 2915a may communicate with the through-channels 2913a, 2914a such that the frame side arms 2923, 2924 may extend partially through the slit 2915a and through the through-channels 2913a, 2914a, as shown in fig. 67. Alternatively, the slit 2915a may not be provided, in which case the through-channels 2913a, 2914a may be configured such that the frame side arms 2923, 2924 can extend through the through-channels 2913a, 2914b from the front to the rear of the interface body side arms 2913, 2914.

In some configurations, the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient. In other configurations, the at least one nasal delivery element may be configured to not seal with a corresponding nostril of the patient. In other constructions, at least one nasal delivery element may be configured to provide a leakage path between the at least one nasal delivery element and a respective nostril of the patient.

The described configuration allows for easy assembly of the frame 2920 with the interface body 2910. In addition, because the proximal portions 2913b, 2914b of the interface body side arms 2913, 2914 are positioned between the patient's face and the proximal portions 2923a, 2924b of the frame side arms 2923, 2924 in use, there is minimal or no contact between the rigid frame and the patient's face in use, thereby enhancing patient comfort.

In alternative constructions, the interface body 2910 and the frame 2920 may be coupled together in other ways, such as by adhesive, molding, mechanical fasteners, clips, or the like.

In an alternative configuration, the interface body side arms 2913, 2914 or the frame side arms 2923, 2924 may include tabs, and the other of the interface body side arms 2913, 2914 or the frame side arms 2923, 2924 may include complementary slits. The tabs may engage with the slots to couple interface body 2910 with frame 2920. For example, the interface body side arms 2913, 2914 may include tabs and the frame side arms 2923, 2924 may include slits, or vice versa.

This configuration may have any one or more of the features described in U.S. patent 10,137,271. The contents of this specification are incorporated herein by reference in their entirety.

Referring to fig. 70-72, interface body 2910 includes a nasal delivery element 2911 configured to seal with a patient's nostril, and optionally includes first and second nasal delivery elements 2911, 2912 configured to seal with respective nostrils of a user. The nasal delivery element 2911 includes a plurality of windings 2911c1, 2911c2 that form bellows portions between the gas flow channel 2925 and the nasal delivery element outlet 2911 a. The nasal interface 2900 is configured to create an asymmetric airflow at the patient's nostrils during use.

In the illustrated construction, the nasal delivery element 2911 includes two windings 2911c1, 2911c2. However, in alternative constructions, the nasal delivery element 2911 may include three or more windings.

In the form shown, each winding 2911c1, 2911c2 includes an outwardly projecting fold. The inwardly recessed folds 2911f1 are disposed between the outwardly protruding folds of the coils 2911c1, 2911c 2. Another inwardly recessed fold 2911f2 is provided between one of the lower sides of the two winding portions 2911c1 and the central body portion 2910a of the interface body 2910.

In some constructions, the interface body 2910 includes a flex region 2911fr. The plurality of windings 2911c1, 2911c2 are located between the flex region 2911fr and the outlet 2911a of the nasal delivery element.

The windings 2911c1, 2911c2 will extend around substantially the entire perimeter of the nasal delivery element 2911 to enable the outlet 2911a of the nasal delivery element to tilt in all directions.

The windings 2911c1, 2911c2 also allow the nasal pillows of the nasal delivery elements 2911, 2912 to compress, whether fully compressed or more compressed on one side than the other. This may help to distribute the load more evenly around the patient's nostrils.

The nasal delivery elements 2911, 2912 may have an unequal number of convolutions around different portions of the nasal delivery elements. For example, one side of the nasal delivery elements 2911, 2912 may have a greater number of convolutions than the other side of the nasal delivery elements. This may allow for greater deflection and/or compression on one side than the other.

In one configuration, the front side of the nasal delivery elements 2911, 2912 may have a greater number of convolutions, while the back side of the nasal delivery elements may have a lesser number of convolutions. In an exemplary configuration, the front side may have three or four windings and the rear side may have two windings.

When provided, the flex region 2911fr can extend around less than the entire perimeter of the nasal delivery element 2911 at or near the base 2911b of the nasal delivery element 2911. That is, there may be one or more flex regions that extend around a portion of the base 2911b of the nasal delivery element but not around the entire perimeter.

In the illustrated configuration, the flex region 2911fr extends at least around the anterior, posterior, and laterally inward portions of the perimeter of the nasal delivery element 2911, but does not extend around the laterally outward portions of the nasal delivery element 2911.

As described above, interface body 2910 may include a softer material than frame 2920 including a more rigid material. A portion of the frame (portion 2920p in fig. 72) is in contact with a portion of interface body 2910 adjacent to flex region 2911fr to reduce or inhibit flexing of the portion of interface body 2910 adjacent to flex region 2911 fr.

The cross-sectional shape of the windings 2911c1, 2911c2 in a direction transverse to the direction of airflow through the nasal delivery element 2911 corresponds to the cross-sectional shape of the base 2911op' of the outlet portion 2911op of the nasal delivery element. For example, the windings may have an elongated cross-sectional shape, such as oval, elliptical, or oblong, or may have any other suitable shape.

The gas inlet 2921 includes an opening 2921o into the gas flow channel 2925 of the interface body 2910, and the opening 2921o is configured to direct an incoming gas flow from the gas inlet 2921 toward the base 2911b of the nasal delivery element.

When the nasal interface includes first and second nasal delivery elements 2911, 2912, each nasal delivery element 2911, 2912 may be configured to seal with a respective nostril of the patient. The first and second nasal delivery elements 2911, 2911 each include a base 2911b, 2912b and an outlet 2911a, 2912a.

The first and second nasal delivery elements 2911, 2912 each include a plurality of convolutions 2911c1, 2912c2 that form respective bellows portions between the gas flow channel 2925 and the outlets 2911a, 2912a of the respective nasal delivery elements.

Interface body 2910 includes at least one flex region 2911fr, 2912fr. The plurality of windings 2911c1, 2911c2, 2912c1, 2912c2 of each nasal delivery element 2911, 2912 are located between the at least one flex region 2911fr, 2912fr and the outlet 2911a, 2912a of the respective nasal delivery element 2911, 2912.

The nasal delivery elements 2911, 2912 may share a combined flex region, or may have separate flex regions 2911fr, 2912fr.

In some constructions, the at least one flex region includes two flex regions 2911fr, 2912fr. The plurality of windings 2911c1, 2911c2, 2912c1, 2912c2 of each nasal delivery element are located between a respective one of the two flex regions 2911fr, 2912fr and the outlet 2911a, 2912a of the respective nasal delivery element 2911, 2912.

The bellows portion and the second flex region 2912fr of the second nasal delivery element 2912 can have any of the features described above with respect to the bellows portion and the first flex region of the first nasal delivery element 2911. The same reference numerals are used to denote the same components, but begin with 2912 instead of 2911.

The first and second winding portions 2911c1, 2911c2, 2912c1, 2912c2 have substantially the same cross-sectional shape as each other. The first winding portion and the second winding portion may have substantially the same size as each other, or may have different sizes from each other.

The first and second windings 2911c1, 2911c2, 2912c1, 2912c2 allow for significant displacement of the outlets 2911op, 2912op to accommodate different facial shapes of different users. This may enhance the seal with the nostrils when desired.

When used in an asymmetric airflow configuration, this displacement may occur while maintaining the ability to achieve an asymmetric airflow at the naris. The wrap minimizes movement at the base of the nasal delivery element, thereby maintaining substantial alignment of the gas flow from the gas inlet 2921 to the base 2911b of the first nasal delivery element 2911, as shown in fig. 71.

The gas inlet 2921 is directed in such a way that a majority of the gas flow is captured within the perimeter of the base 2911b of the first nasal delivery element 2911. The base 2911b may provide a funnel effect to direct the airflow to the outlet 2911a. This may not occur throughout the patient's respiratory cycle as the patient exhales and disrupts the airflow.

Fig. 71 also shows a schematic flow velocity profile VP at the inlet of the flow channel 2925.

The flex regions 2911fr, 2912fr adjacent to the base of the nasal delivery elements facilitate movement of the central interface body portion 2910a between the nasal delivery elements 2911, 2912 when the nasal interface 2900 is worn to facilitate adaptation to different facial anatomies.

The nasal delivery elements 2911, 2912 including bellows portions and the outlet portions 2911op, 2912op may have a constant wall thickness. In some constructions, the flex regions 2911fr, 2912fr may also have the same constant wall thickness. Or the wall thickness may vary.

The bellows portions and/or flex regions described for nasal interface 2900 may be used with any of the other nasal interfaces 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 3000, 3100, 3200, 3300 described herein that may help achieve and maintain asymmetric airflow in nasal interfaces by minimizing movement at the base of the nasal delivery element, maintaining the airflow substantially aligned from the gas inlet toward the base of the nasal delivery element, and being able to fit into different nostrils of different users.

Similarly, the nasal interface 2900 having bellows portions and/or flex regions may include any one or more features described herein with respect to other nasal interfaces 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 3000, 3100, 3200, 3300 that facilitate the creation of asymmetric airflows. For example, the nasal interface 2900 with bellows portion and/or flex region may include one or more of the following: a nasal interface configuration configured to direct more of the incoming gas to a first gas flow configured to be provided, in use, substantially to a first naris of a patient than to a second gas flow configured to be delivered, in use, substantially to a second naris of the patient to create an asymmetric gas flow at the patient's nasal airway throughout the patient's respiratory cycle; A nasal interface configured to provide a greater dynamic pressure at a first nostril of the patient in use and a lesser dynamic pressure at a second nostril of the patient in use to create an asymmetric flow of gas at the patient's nasal airway throughout the patient's respiratory cycle; a nasal interface configuration comprising a flow splitting portion for unequally splitting a flow of gas from the gas inlet into a first flow of gas configured to be provided substantially to the first nasal delivery element and a second flow of gas configured to be provided substantially to the second nasal delivery element, wherein the first flow of gas is configured to deliver more gas along the first flow than along the second flow of gas to create an asymmetric flow of gas at the nasal airway of the patient throughout the respiratory cycle of the patient; A nasal interface configuration comprising a bypass restrictor to provide a pressure drop across the nasal interface between the first and second nasal delivery elements when gas is delivered from the gas inlet to the first and second nasal delivery elements such that the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element, wherein the nasal interface comprises a bias flow restrictor for the flow of gas out of the nasal interface; a nasal interface configuration configured to create a pressure differential between the first nasal delivery element and the second nasal delivery element when gas is delivered from the gas inlet to both the first nasal delivery element and the second nasal delivery element such that a pressure at the first nasal delivery element is higher than a pressure at the second nasal delivery element; a nasal interface configuration comprising at least one flow restrictor for restricting flow of gas through the nasal interface such that when gas is delivered from the gas inlet to the first nasal delivery element and the second nasal delivery element, the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element; a nasal interface configuration comprising a bypass restrictor providing a cross-sectional area of a portion of the gas flow path, wherein the first and second nasal delivery elements each comprise an internal cross-sectional area, wherein the internal cross-sectional areas together provide a combined cross-sectional area of the nasal delivery elements, and wherein the cross-sectional area of the portion of the gas flow path is greater than 0 to about 1.5 times the combined cross-sectional area of the nasal delivery elements; a nasal interface configuration wherein the first nasal delivery element is proximal to the gas inlet and the second nasal delivery element is distal to the gas inlet, wherein the nasal interface comprises a bypass restrictor providing a cross-sectional area of a portion of the gas flow path, wherein the first nasal delivery element and the second nasal delivery element each comprise an internal cross-sectional area, and wherein the internal cross-sectional area of the nasal delivery element is related to the cross-sectional area of the portion of the gas flow path so as to create, in use, an asymmetric gas flow from the nasal delivery element.

As shown in fig. 70 and 71, the nasal delivery elements 2911, 2912 may include outlet portions 2911op, 2912op for receipt in the nostrils of the patient. The outlet portions 2911op, 2912op may be concave, as indicated by curved arrows. The concave surface may extend around the perimeter of the outlet portion.

In alternative configurations, which may be used with or without bellows portions and/or flex regions, the nasal delivery elements 2911, 2912 may include outlet portions 2911op, 2912op for receipt in the patient's nostrils, and the outlet portions of the nasal delivery elements may include a concave CCS and a convex CVS. This configuration is shown in fig. 73 and 74.

In this configuration, the nasal interface 2900 includes an interface body 2910 that includes a nasal delivery element 2911. The nasal delivery element 2911 includes an outlet 2911a and is configured to seal with the nostrils of the patient.

The nasal interface includes a gas inlet 2921 for delivering breathing gas into the nasal interface 2900. The gas inlet 2921 and the nasal delivery element 2911 are in fluid communication with the gas flow channel 2925 of the interface body to deliver breathing gas from the gas inlet 2921 through the nasal delivery element 2911.

The nasal delivery element 2911 includes an outlet portion 2911op for receipt within the nostril of the patient, wherein the outlet portion includes an outlet 2911a, a concave CCS, and a convex CVS. The convex CVS is closer to the midline plane MP of the nasal interface. Concave CCS is farther from midline plane MP.

In some constructions, the concave CCS is disposed behind the convex CVS.

A configuration with a concave CCS and convex CVS may be used in a nasal interface 2900 configured to create an asymmetric airflow at the patient's nostrils during use. Or a configuration with a concave CCS and convex CVS may be used in a nasal interface 2900 configured to create a symmetrical airflow at the patient's nares during use.

In the illustrated construction, the concave CCS and convex CVS are surfaces that are opposite one another.

The convex CVS is convex over at least half of the length of the outlet portion 2911op extending from the base portion 2911op' of the outlet portion to the outlet portion 2911a of the nasal delivery element 2911, optionally over at least two thirds of the length, optionally over substantially the entire length excluding the outlet portion tip 2911op″ including the outlet portion 2911 a.

The concave surface CCS is concave over at least half of the length of the outlet portion 2911op extending from the base portion 2911op' of the outlet portion to the outlet portion 2911a of the nasal delivery element 2911, optionally over at least two-thirds of the length, optionally over substantially the entire length excluding the outlet portion tip 2911op″ including the outlet portion 2911 a.

The convex CVS is configured to be located, in use, proximal to a patient's nasal septum. The concave CCS is configured to be located, in use, distal to the patient's nasal septum.

Convex surface CVS is adjacent to midline plane MO of nasal interface 2900. Concave surface CVS is distal to midline plane MP of nasal interface 2900.

Fig. 74 shows a cross-section of the nasal delivery element 2911 along line a-m in the direction of the arrow in the top of fig. 74.

Referring to fig. 74 (m) and (a) - (e), the convex CVS extends around at least 1/6 of the perimeter of the outlet portion, optionally around at least 1/5 of the perimeter of the outlet portion 2911 op.

The outlet portion 2911op is configured such that the convex CVS smoothly transitions to the concave CCS around the perimeter of the outlet portion 2911 op.

In the configuration shown in fig. 74, sections (a) through (d) show a convex CVS extending from the posterior inner region of the nasal delivery element 2911 to the anterior inner region of the nasal delivery element 2911, section (e) shows a relatively flat (i.e., neither significantly convex nor significantly concave) transition surface TS, sections (f) through (k) show a concave CCS extending from the anterior region of the nasal delivery element 2911 to the posterior outer region of the nasal delivery element 2911, and sections (l) and (m) show a relatively flat transition surface TS in the posterior region of the nasal delivery element 2911.

The convex surface CVS extends to a point between the sections (a) and (m).

When the nasal interface 2900 includes two nasal delivery elements 2911, 2912, the nasal delivery elements 2911, 2912 may have the same configuration as each other (e.g., mirror image across the midline plane MP of the nasal interface 2900) or may be configured differently from each other. The same reference numerals are used to denote the same components, but begin with 2912 instead of 2911.

Thus, the nasal delivery element 2911 can include a first nasal delivery element. The interface body 2910 includes a second nasal delivery element 2912 configured to seal with a respective nostril of the patient, wherein the second nasal delivery element 2912 is in fluid communication with the gas inlet 2921 via the gas flow channel 2925, and wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 each include a base 2911b, 2912b and an outlet 2911a, 2912a.

The first and second nasal delivery elements 2911, 2912 each include an outlet portion 2911op, 2912op for receipt in a respective nostril of the patient, wherein each outlet portion 2911op, 2912op includes a concave CCS and a convex CVS.

Because the nasal delivery elements 2911, 2912 mirror each other, the convex CVSs are proximate to each other and are configured to contact the nostrils proximate to the patient's nasal septum. The concave CCSs are remote from each other and are configured to contact the nostrils away from the patient's nasal septum.

The nasal delivery elements 2911, 2912 have any suitable shape that is capable of fitting within the nostrils of a patient. For example, in some constructions, the nasal delivery element has an elongate shape in cross section (in a direction transverse to the flow of air through the nasal delivery element). The nasal delivery element may be beveled such that a long dimension of the cross-sectional shape extends from a front interior of the nasal delivery element to a rear exterior of the nasal delivery element, and such that a short dimension of the nasal delivery element is transverse or orthogonal to the long dimension.

The cross-sectional shape may be oval, elliptical or oblong, or may be any other suitable shape.

The concave CCS allows greater pressure to be applied to the periphery of the nostrils away from the patient's nasal septum. The concavity resists the forces created by the tension of the headgear 200 by abutting the outer portions of the nostrils, which are less sensitive and thicker than the areas near the nasal septum. The convex CVS does not oppose the forces created by the tension of the headgear 200 and is directed toward the nasal septum (the thinner, more sensitive area of the nose) to help seal the nasal delivery elements 2911, 2912 in the nostrils.

The interface body 2910 having a nasal delivery element with a concave CCS and a convex CVS and/or having a bellows portion may be used in a nasal interface having any suitable gas inlet configuration. For example, the gas inlet 2921 may be centered on the midline plane MP of the nasal interface 2900, as described below, or may be a side inlet into the nasal interface 2900.

Referring to fig. 75-78, nasal interface 2900 includes an interface body 2910 that includes a nasal delivery element 2911. The nasal delivery element 2911 is configured to seal with the nostrils of the patient.

Interface body 2910 includes a nasal delivery element 2911 configured to seal with the nostrils of the patient.

The nasal interface 2900 includes a gas inlet 2921 for delivering breathing gas into the nasal interface 2900. The gas inlet 2921 and the nasal delivery element 2911 are in fluid communication with the gas flow channel 2925 or gas chamber of the interface body 2910 to deliver breathing gas from the gas inlet 2921 through the nasal delivery element 2911.

The gas inlet 2921 has a portion 2921p that extends outside of the interface body 2910. The portion 2921p is in a fixed position offset relative to the midline plane MP bisecting the nasal interface 2900. The portion 2921p is angled obliquely relative to the midline plane MP to position the opening of the gas inlet 2921a away from the midline plane MP.

As shown in fig. 77, the end 2921b of the portion 2921p proximate the gas flow channel 2920 is offset from the midline plane MP by a distance DI of up to about 40mm, optionally between about 10mm and about 40 mm.

End 2921b includes an opening 2921o.

The distance DI is taken between the midline plane MP and the axis IA of the gas inlet 2921 at the point where the inner end of the gas inlet 2921 intersects the gas flow channel 2925.

As shown in fig. 75, portion 2921p is obliquely angled at an angle a of greater than 0 degrees and up to about 70 degrees relative to the midline plane, optionally between about 10 degrees and about 70 degrees relative to the midline plane.

As described above, the nasal interface 2900 may include a first nasal delivery element and a second nasal delivery element. The nasal delivery element 2911 comprises a first nasal delivery element, wherein the interface body 2910 comprises a second nasal delivery element 2912 configured to seal with a respective nostril of the patient, wherein the second nasal delivery element 2912 is in fluid communication with the gas inlet 2921 via the gas flow channel 2925, and wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 each comprise a base 2911b, 2912b and an outlet 2911a, 2912a.

As shown in fig. 76, in some constructions, the portion 2921p is at an angle B of greater than 0 degrees and up to about 40 degrees relative to a second plane SP that extends through the first and second nasal delivery elements 2911, 2912 from the bases 2911B, 2912B to the outlets 2911a, 2911B of the first and second nasal delivery elements.

The gas inlet 2921 includes an opening 2921o into the gas flow channel 2925 of the interface body 2910, and the opening 2921o is configured to direct an incoming gas flow from the gas inlet 2921 toward the base 2911b of the nasal delivery element 2911.

In the configuration shown in fig. 75-77, the gas inlet 2921 includes an opening 2921o into the gas flow channel 2925 of the interface body 2910, and the opening 2921o is configured to direct more of the incoming gas toward the base 2911b of the first nasal delivery element 2911 than toward the base 2912b of the second nasal delivery element 2912. This helps to provide an asymmetric airflow towards the patient's nares.

In an alternative configuration shown in fig. 78, the gas inlet 2921 includes an opening 2921o into the gas flow channel 2925 of the interface body 2910, and the opening 2921o is configured to direct the flow of inlet gas to the chamber wall 2926 between the base 2911b of the first nasal delivery element 2911 and the base 2912b of the second nasal delivery element 2912. This helps to provide a substantially symmetrical flow of air towards the patient's nares. Because the gas inlet 2921 directs the gas flow substantially toward the chamber wall 2926 between the first and second nasal delivery elements 2911, 2912, the gas flow is split substantially equally between the nasal delivery elements, and the asymmetric gas flow is negligible or non-existent.

By having offset and angled gas inlets 2921, the portion 2921P is positioned away from the patient's mouth. This allows the patient to still eat, drink and/or communicate with the mouth.

By having an offset and angled gas inlet 2921, the seal of the nasal delivery element is less prone to break when the patient is lying on his side than, for example, the full side entry interface shown in fig. 1. For interfaces of the type shown in fig. 1, the seal of the nasal pillows can be broken when the patient is lying on his side with the gas inlet extending.

In some constructions, the nasal interface 2900 includes an interface body 2910 and a frame 2920 that cooperate to define a gas flow channel 2925 therein. In some alternative constructions, the gas flow channel 2925 may instead be defined substantially or solely by the interface body 2910, and the frame 2920 or gas manifold may not be provided.

When provided, the frame 2920 may support the interface body 2910 and/or one or more other components (such as the gas inlet 2921, the headgear 200, and/or the interface body 2910). The gas inlet 2921 may be formed as part of the interface body 2910 or as part of the frame 2920, or may be formed separately from and coupled to the interface body 2910 and/or the frame 2920.

As described above, the nasal interface 2900 may be configured to create an asymmetric airflow at the patient's nostrils when in use. The nasal interface 2900 may have any one or more of the features described herein for the other nasal interfaces 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 3000, 3100, 3200, 3300 that help provide asymmetric airflow at the patient's nostrils in use.

For example, in some configurations, the nasal interface 2900 includes a first nasal delivery element 2911 and a second nasal delivery element 2912, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are each configured to seal with a respective nostril of a patient, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are in fluid communication with the gas inlet 2921 via the gas flow channel 2925, wherein the first nasal delivery element 2911 is proximate to the gas inlet 2921 and the second nasal delivery element 2912 is distal to the gas inlet 2921, wherein the nasal interface 2900 is configured to receive an ingress gas from the gas inlet 2921 and provide a first gas flow and a second gas flow from the ingress gas, the first gas flow configured to be substantially provided to the first nostril of the patient in use, the second gas flow configured to be substantially provided to the second nostril of the patient in use, and the nasal interface is configured to direct more ingress gas to the first gas flow than the second gas flow to create an asymmetric gas flow at the patient's nasal airway throughout the respiratory cycle.

For example, in some configurations, the nasal interface 2900 includes a first nasal delivery element 2911 and a second nasal delivery element 2912, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are each configured to seal with a respective nostril of a patient, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are in fluid communication with the gas inlet via the gas flow channel 2925, wherein the nasal interface 2900 is configured to provide a greater dynamic pressure at the first nostril of the patient in use and a lesser dynamic pressure at the second nostril of the patient in use to create an asymmetric gas flow at the nasal airway of the patient throughout the respiratory cycle of the patient.

For example, in some configurations, the nasal interface 2900 includes a first nasal delivery element 2911 and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element 2912 are each configured to seal with a respective nostril of a patient, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are in fluid communication with the gas inlet 2921 via the gas flow channel 2925, wherein the nasal interface includes a split to split the flow of gas from the gas inlet unequally into a first flow of gas configured to be substantially provided to the first nasal delivery element 2911 and a second flow of gas configured to be substantially provided to the second nasal delivery element 2912, wherein the first flow of gas is configured to deliver more gas along the first flow of gas than along the second flow of gas to create an asymmetric flow of gas at the nasal airway of the patient throughout the respiratory cycle of the patient.

For example, in some configurations, the nasal interface 2900 includes first and second nasal delivery elements 2911, 2912, wherein the first and second nasal delivery elements 2911, 2912 are each configured to seal with a respective nostril of a patient, wherein the first and second nasal delivery elements 2911, 2912 are in fluid communication with the gas inlet 2921 via the gas flow channel 2925, wherein the nasal interface 2900 includes a bypass restrictor to provide a pressure drop across the nasal interface 2900 between the first and second nasal delivery elements 2911, 2912 when gas is delivered from the gas inlet 2921 to the first and second nasal delivery elements 2911, 2912 such that the pressure at the first nasal delivery element 2911 is higher than the pressure at the second nasal delivery element 2912, and wherein the nasal interface 2900 includes a flow restrictor to restrict the flow of gas out of the nasal interface.

The pressure drop across the interface body 2910 may be such that when there is a flow of gas from the gas inlet 2921 to the first and second nasal delivery elements 2911, the flow of gas from the gas inlet 2921 to the first nasal delivery element 2911 is greater than the flow of gas from the gas inlet 2921 to the second nasal delivery element 2912.

For example, in some configurations, the nasal interface 2900 includes a first nasal delivery element 2911 and a second nasal delivery element 2912, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are each configured to seal with a respective nostril of a patient, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are in fluid communication with the gas inlet 2921 via the gas flow channel 2925, wherein the nasal interface 2900 is configured to generate a pressure differential between the first nasal delivery element 2911 and the second nasal delivery element 2912 when gas is delivered from the gas inlet 2921 to both the first nasal delivery element 2911 and the second nasal delivery element 2912 such that the pressure at the first nasal delivery element 2911 is higher than the pressure at the second nasal delivery element 2912.

For example, in some configurations, the nasal interface 2900 includes a first nasal delivery element 2911 and a second nasal delivery element 2912, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are each configured to seal with a respective nostril of a patient, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are in fluid communication with the gas inlet 2921 via the gas flow channel 2925, wherein the nasal interface 2900 includes at least one gas flow restrictor that restricts a flow of gas through the nasal interface such that a pressure at the first nasal delivery element 2911 is higher than a pressure at the second nasal delivery element 2912 when gas is delivered from the gas inlet 2921 to the first nasal delivery element 2911 and the second nasal delivery element 2912.

For example, in some configurations, the nasal interface 2900 includes a first nasal delivery element 2911 and a second nasal delivery element 2912, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are each configured to seal with a respective nostril of a patient, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are in fluid communication with the gas inlet 2921 via the gas flow channel 2925, wherein the first nasal delivery element 2911 is proximate to the gas inlet 2921 and the second nasal delivery element 2912 is distal to the gas inlet 2921, wherein the nasal interface 2900 includes a bypass restrictor providing a cross-sectional area of a portion of the gas flow channel 2925, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 each include an inner cross-sectional area, wherein the inner cross-sectional areas together provide a combined cross-sectional area of the nasal delivery elements 2911, 2912, and wherein the cross-sectional area of the portion of the gas flow channel 2925 is greater than 0 to about 1.5 times the combined cross-sectional area of the nasal delivery elements 2911, 2912.

For example, in some configurations, the nasal interface 2900 includes a first nasal delivery element 2911 and a second nasal delivery element 2912, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are each configured to seal with a respective nostril of a patient, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 are in fluid communication with the gas inlet 2921 via the gas flow channel 2925, wherein the first nasal delivery element 2911 is proximate to the gas inlet 2921 and the second nasal delivery element 2912 is distal to the gas inlet 2921, wherein the nasal interface 2900 includes a bypass restrictor providing a cross-sectional area of a portion of the gas flow channel 2925, wherein the first nasal delivery element 2911 and the second nasal delivery element 2912 each include an inner cross-sectional area, and wherein the inner cross-sectional areas of the nasal delivery elements 2911, 2912 are related to the cross-sectional area of the portion of the gas flow channel 2925 such that, in use, an asymmetric gas flow is generated from the nasal delivery elements 2911, 2912.

The nasal interface 2900 may include one or more bias flow vents 2940 formed between the interface body 2910 and the frame 2920.

Referring to fig. 79 to 84, the nasal interface 2900 includes: interface body 2910, the interface body including a cushion and configured to substantially form a seal with a patient's nasal airway, the interface body 2910 configured to deliver gas to a patient's first nostril and a patient's second nostril; and a frame 2920 configured to engage with the interface body 2910.

Interface body 2910 and frame 2920 are configured such that one or more bias flow vents 2940 are formed between interface body 2910 and frame 2920 when interface body 2910 and frame 2920 are engaged with each other.

Interface body 2910 includes a portion of bias current vent 2940. The frame 2920 includes a portion of the bias current vent 2940.

Interface body 2910 includes a first portion of bias vent 2940, and frame 2920 includes a second portion of bias vent 2940.

For example, the first portion of the bias flow drain may include a flow channel and the second portion of the bias flow drain may include a top wall for the flow channel. Or the second portion of the bias flow drain may include a flow channel and the first portion of the bias flow drain may include a top wall for the flow channel. Or the first portion of the bias flow vent and the second portion of the bias flow vent may each include a flow passage. These features may be provided in any suitable combination for different bias flow vents.

In the configuration shown in fig. 81 and 82, the frame 2920 includes a flow channel 2940a of a bias flow vent, and the interface body 2910 includes a top wall 2940b of the bias flow vent. The flow channel 2940a and the top wall 2940b together form a bias flow vent 2940 when the frame 2920 is engaged with the interface body 2910.

The nasal interface may include a single bias flow vent 2940 or may include multiple bias flow vents 2940.

In the illustrated construction, the bias flow vents 2940 are arranged in at least one array around a portion of the nasal interface 2900. As shown in fig. 80, bias flow vents 2940 are disposed in the upper array 2940u at an upper edge of the frame 2940 and in the lower array 2940l at a lower edge of the frame 2940. In other constructions, only the upper array 2940u or only the lower array 2940l may be provided.

The at least one array of bias flow vents 2940 is configured to direct gas from the nasal interface in a divergent pattern. An exemplary pattern is represented by bias flow direction arrow BFD in fig. 80 and 82.

In some configurations, the divergent mode includes an airflow at least partially laterally outward from interface body 2910 and/or frame 2920. In some configurations, the divergent mode additionally or alternatively includes an airflow at least partially upward and/or downward from the interface body 2910 and/or the frame 2920.

The array may follow the contours of the patient's lips. The array may direct the flow of air away from the patient's face in a divergent pattern or in an intermediate flow direction to minimize ventilation air flow.

The divergent pattern may be at least substantially conical. By having a substantially conical shape, any overlap of adjacent airflows is minimized to avoid minimization of kinetic energy of the airflows.

The flow exiting bias flow vent 2940 may also be at least substantially conical.

The degree of upward and downward tilting of the diverging air flow may depend on how close the upper and lower arrays 2940u, 2940l of bias flow discharge orifices 2940 are to one another. If the upper and lower arrays 2940u, 2940l are closer to each other than shown in FIG. 80, the degree of upward and downward tilting may be more aggressive than shown to minimize or avoid overlapping of the air flows from the upper and lower arrays 2940u, 2940 l.

The bias flow vent 2940 may be in fluid communication with the gas flow channel 2925 via one or more bias flow passages 2940 c. One configuration of the bias flow path 2940c is shown in fig. 83 and 84. The bias flow flows from the gas flow channel 2925 through the bias flow channel 2940c out of the bias flow discharge port 2940 as indicated by the arrows in fig. 83 and 84.

The nasal interface 2900 may have any suitable number of bias flow passages 2940c. In one configuration, one bias flow passage 2940c may be provided for each bias flow discharge 2940. In this configuration, there will be a corresponding number of bias flow vents 2940 and bias flow passages 2940c. In another configuration, two or more bias flow vents 2940 may share a bias flow channel 2940c. In this configuration, the bias flow passage 2940c will be fewer than the bias flow discharge port 2940.

The flow biasing passage 2940c may be in the form of a flow channel. The flow channel may be a continuation of the flow channel 2940a and may include a top wall 2940b along the length, or may have any other configuration described herein for biasing the discharge port 2940.

Interface body 2910 includes a central interface body portion 2910a, and frame 2920 includes a central frame body portion 2920a. The central interface body portion 2910a and the central frame body portion 2920a are configured to engage one another to define a gas flow channel 2925 for delivering, in use, breathing gas from the gas inlet 2921 through the interface body 2910 to the first nostril of the patient and the second nostril of the patient.

The central frame body portion 2920a includes a gas inlet 2921. Alternatively, the central interface body portion 2910a may include a gas inlet 2921, or a gas inlet may be provided by both the central frame body portion 2920a and the central interface body portion 2910 a.

In some constructions, the gas inlet 2921 is disposed at or near one side of the central frame body portion 2920a, and wherein at least one of the one or more bias flow vents 2940 is disposed at or near the other side of the central frame body portion 2920a between the interface body 2910 and the frame 2920.

In some constructions, the interface body 2910 of the nasal interface 2900 may include a single outlet for delivering gas to the first and second nostrils of the patient, rather than having two nasal delivery elements. The single outlet may be of the type described herein for a single outlet construction nasal interface.

In an alternative configuration, interface body 2911 includes a first nasal delivery element 2911 having a first outlet 2911a and a second nasal delivery element 2912 having a second outlet 2912a, wherein each of the first nasal delivery element 2911 and the second nasal delivery element 2912 are configured to seal with a respective nostril of a patient.

The bias flow vent 2940 may be used in a nasal interface 2900 configured to create an asymmetric airflow at the patient's nostrils in use. Or the bias flow vent may be used in a nasal interface 2900 configured to create a symmetrical airflow at the patient's nares in use.

By having the bias flow vent 2940 formed in part by the frame 2920 and in part by the interface body 2910, the frame 2920 and the interface body 2910 can be easily formed by molding and the bias flow vent 2940 is unobtrusive.

The nasal interface 2900 may have any one or more features described herein for the nasal interface 2900. The nasal interface 2900 may have any one or more features described herein for nasal interfaces 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 3000, 3100, 3200, 3300. Any of the nasal interfaces 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 3000, 3100, 3200, 3300 may have any one or more features described herein for the nasal interface 2900.

Fig. 85 illustrates another example structured patient interface including an example structured nasal interface 3000.

Unless described below, the features, functions, and options described for the nasal interface 3000 are the same as those described for the nasal interface 2900, and like reference numerals denote like parts, except that 100 is added.

The patient interface includes a nasal interface 3000 that includes an interface body 3010 and a frame 3020. The patient interface also includes headgear 3500 to at least maintain the patient interface in position on the patient in use.

The nasal interface 3000 includes an interface body 3010 that includes a first nasal delivery element 3011 configured to seal with a first nostril of a patient and a second nasal delivery element 3012 configured to seal with a second nostril of the patient.

In some constructions, the nasal interface 3000 includes an interface body 3010 and a frame 3020 or gas manifold that cooperate to define a gas flow passage 3025 therein. In some alternative constructions, the gas flow channel 3025 may instead be defined substantially or solely by the interface body 3010, and the frame 3020 or the gas manifold may not be provided.

The body portion 3031 of the frame 3020 may be engaged with the interface body 3010 to couple these components together.

The nasal interface 3000 includes a gas inlet 3021 for delivering breathing gas into the nasal interface 3000. The gas inlet 3021 is positioned closer to the first nasal delivery element 3011 than to the second nasal delivery element 3012.

The gas inlet 3021 and the nasal delivery elements 3011, 3012 are in fluid communication with a gas flow passage 3025 or gas chamber of the interface body 3010 to deliver breathing gas from the gas inlet 3021 through the nasal delivery elements 3011, 3012.

In some constructions, the gas inlet 3021 is positioned substantially across the gas flow path 3025 directly opposite the first nasal delivery element 3011. The gas inlet 3021, or at least the outlet 3021b of the gas inlet 3021, may be aligned with the first nasal delivery element 3011 and optionally with the first outlet 3011a of the first nasal delivery element 3011.

Referring to fig. 87, 92, 95, 96, 97 and 98, the nasal interface 3000 includes a bias flow vent 3040 for allowing airflow from the nasal interface 3000 to flow out to the surrounding environment. The bias flow drain 3040 is positioned closer to the second nasal delivery element 3012 than to the first nasal delivery element 3011. The bias flow discharge 3040 includes one or more elongated bias flow apertures 3041.

The bias flow vent 3040 enables airflow to flow from the nasal interface 3000 to the surrounding environment. The bias flow vent 3040 can provide flow resistance to gases passing between the nasal interface 3000 and the surrounding environment. The bias flow discharge 3040 can act as a bias flow restrictor.

In some configurations, the bias flow vent 3040 is positioned substantially across the gas flow channel 3025 directly opposite the second nasal delivery element 3012.

It is desirable to have a high bias flow to flush gas well from the patient (e.g., upper airway) and/or nasal interface 3000 during use. Achieving good flushing of the patient's airway reduces the amount of dead space, thereby increasing ventilation efficiency. However, there may be a tradeoff with one or more of noise, turbulence, humidity performance, and oxygen consumption. An example of the relationship between pressure and bias flow at the patient is shown in fig. 101.

One way to increase the bias flow is to increase the number and/or size of the annular holes of the bias flow discharge. However, a problem with annular diverging holes is that noise may be generated when, for example, the gas flow crosses over the holes and interacts with walls between the holes (e.g., wall edges that may extend transverse to the direction of gas flow through the nasal interface), and/or when the gas within the nasal interface is diverted to flow out through the holes. In addition, since the provided gas may be humidified to improve compliance with the asymmetric gas flow, there is a risk of condensate accumulating and clogging the plurality of small holes, which may have undesirable effects such as reducing the asymmetric gas flow.

Having the elongated flow deflecting aperture 3041 can increase the flow of the flow deflecting while avoiding having multiple transverse aperture edges that the gas flow would impinge upon as it flows along the elongated flow deflecting aperture and turns to exit through the aperture.

As shown in fig. 95, the one or more elongated offset holes 3041 can be substantially aligned with the second nasal delivery element 3012 and optionally with the second outlet 3012a of the second nasal delivery element. This allows the one or more elongated offset holes 3041 to be positioned proximate to the patient's nostril (the downstream nostril) furthest from the gas inlet 3021 during use to create a short flow path out of the downstream nostril to the surrounding environment for good irrigation. If the one or more bias flow holes are not significantly aligned with the second nasal delivery element 3012, the gas may have to travel farther and/or change direction in order to leave the nasal interface, which may increase the pressure drop between the patient and the outlet of the one or more elongated bias flow holes 3041.

At least one of the one or more elongated offset holes 3041 extends from a position proximate to the gas inlet 3021 to a position at or proximate to an end 3025b of the gas flow channel 3025, as shown, for example, in fig. 99. The end 3025b of the gas flow passage 3025 may be the opposite end of the gas flow passage from the end 3025a where the gas inlet 3021 is located or is adjacent. The end 3025b of the gas flow path may be located at or near the opposite side of the interface body 3010 from the gas inlet 3021. For example, if the gas inlet 3021 is positioned adjacent to a left naris of a patient in use, the end 3025b of the gas flow conduit 3025 may be adjacent to the right naris of the patient in use. Or if the gas inlet 3021 is positioned, in use, adjacent to the patient's right naris, the end 3025b of the gas flow passage 3025 may, in use, be adjacent to the patient's left naris.

Referring to fig. 97, 99 and 100, an end 3041a of the at least one of the one or more elongated offset holes 3041 is proximate to a perimeter 3021c of an outlet 3021b of the gas inlet 3021.

Referring to fig. 99 and 100, the end 3041a of the one or more elongated flow deflecting holes 3041 may be provided at a minimum distance 3047 from the periphery 3021c of the outlet 3021b of the gas inlet 3021.

In some constructions, the minimum distance is at least about 0.4mm. The minimum distance 3047 may be selected to be easy to mold.

If the start end 3041a of the one or more elongated bias flow holes 3041 is positioned too close to the perimeter 3021c of the outlet 3021b of the gas inlet 3021, asymmetric gas flow will be reduced because the gas flow will travel directly from the gas inlet 3021, through the gas flow passage 3025, and out of the bias flow discharge port 3040. Positioning the start end 3041a of the one or more elongated bias flow holes 3041 away from the periphery 3021c may minimize such shorting from the gas inlet 3021 to the bias flow discharge 3040 and/or may increase asymmetric gas flow. In some constructions, the minimum distance may be at least about 1mm, alternatively at least about 2mm, alternatively at least about 5mm.

In the illustrated construction, the nasal interface 3000 includes an interface body 3010 and a frame 3020. The interface body 3010 includes first and second nasal delivery elements 3011, 3012, and the frame includes a bias flow vent 3040.

The frame 3020 may be made of any suitable material. The frame may be rigid or semi-rigid. In some constructions, the frame material may include nylon or polyolefin, such as polypropylene, high density polyethylene, or low density polyethylene.

The interface body 3010 may be configured as a pad. Interface body 3010 may be formed of a soft, flexible material, such as silicone, thermoplastic elastomer, or other polymers known in the art.

Referring to fig. 87, 88, 92, 95, 96, and 98, the frame 3020 can include a recess 3042 and the bias flow drain 3040 is located in the recess 3042.

In the illustrated construction, a recess 3042 is provided at the front of the frame 3020. In an alternative configuration, the recess 3042 may be provided in the back of the frame 3020.

In the illustrated construction, the recess 3042 has an irregular shape. That is, the sides and the interior angles of the shape are not all the same.

The recess may have an irregular polygonal shape. In one exemplary configuration, the recess has a trapezoidal shape.

By providing the recess 3042 with an irregular shape, the length of at least one of the one or more elongated bias holes 3041 may be maximized. The irregularly shaped recess 3042 can allow for placement of a plurality of elongated bias flow holes 3041 having different lengths. The irregular shape increases the likelihood that a portion of the recess 3042 remains unobstructed for airflow between the nasal interface 3000 and the surrounding environment if a portion of the recess 3042 is obstructed, for example, by a nasal pillow or other object.

The frame 3020 may include one or more protrusions or ribs to further recess the diffuser 3050 into the frame. For example, the protrusions or ribs may be frame portions of fig. 89 that extend across the top and bottom of the diffuser 3050.

For example, as shown in fig. 92, the frame 3020, the recess 3042, and the at least one elongated bias flow hole 3041 are curved in the frame front-rear direction. This also reduces the likelihood of the one or more elongated offset holes 3041 becoming completely blocked.

The one or more offset holes 3041 have one dimension that is larger than the other dimension.

In the illustrated construction, the one or more bias flow holes 3041 have a substantially rectangular shape. The one or more bias-flow holes may have any other suitable shape, such as elliptical, oval, rounded rectangular, or stadium shape. Fig. 95 shows a rounded rectangular shape.

Referring to fig. 102 (b), one dimension 3041c is larger than the other dimension 3041d. One dimension 3041c is a dimension extending in a direction along the length of the gas flow passage 3025 in the nasal interface 3000.

The size, and thus aspect ratio, of the one or more elongated bias apertures 3041 may be varied while still providing the desired characteristics.

The one or more elongated bias apertures 3041 are elongated in a direction extending across the nasal interface 3000. In some constructions, the one or more elongated bias flow holes 3041 may extend in a direction along the gas flow passage 3025 that is generally aligned with a left-to-right or right-to-left direction of the nasal interface 3000 in use. In some constructions, the one or more elongated bias apertures 3041 may extend substantially horizontally in use. In other constructions, the one or more elongated bias apertures 3041 can extend in a generally up-down direction of the nasal interface. In some constructions, the one or more elongated bias apertures 3041 may extend substantially vertically in use. In some constructions, the one or more elongated deflection holes may extend at one or more oblique angles relative to a longitudinal axis extending along the gas flow passage 3025.

In some constructions, the ratio of one dimension 3041c to the other dimension 3041d is about 1.1 or greater, alternatively about 1.5 or greater, alternatively about 1.75 or greater, alternatively about 2 or greater, alternatively about 2.5 or greater. In some constructions, the ratio of one dimension 3041c to the other dimension 3041b is up to about 20, alternatively up to about 17, and alternatively up to about 15.

Referring to fig. 102, an elongated bias current aperture 3041 having a high aspect ratio (e.g., as shown in fig. 102 (b), i.e., one dimension 3041c is significantly larger than the other dimension 3041 d) provides a larger "fanout" region than a bias current aperture having a low aspect ratio (e.g., as shown in fig. 102 (a)). The "fan-out" area is schematically represented by a combination of white areas and shaded areas shown in fig. 102. If the area of the elongated offset hole 3041 of fig. 102 (a) is the same as the area of the elongated offset hole 3041 of fig. 102 (b), the area of the fan-out area of fig. 102 (b) is greater than the area of the fan-out area of fig. 102 (a).

The "fanout" zone is intended to refer to the area into which gas diffuses as it exits the deflector hole as it travels from within the patient interface to the surrounding environment. This can be taken at any distance (say 10 mm) from the outlet of the flow deflecting aperture. The larger "fanout" region (i.e., larger area) has a greater effect on the reduction in flow velocity of the airflow exiting the flow deflecting aperture 3041.

The bias flow can be increased by increasing the cross-sectional area of the one or more elongated bias holes 3041, such as increasing the size 3041 b. An increased bias flow may increase the asymmetric airflow.

Fig. 103 shows an alternative configuration in which the elongated offset aperture 3041 is narrower than that of fig. 96. That is, the ratio of one dimension 3041c to the other dimension 3041d of this configuration is greater than that of fig. 96.

Fig. 104 shows another alternative configuration in which the elongated offset aperture 3041 is wider (in the vertical direction) than fig. 96. That is, the ratio of one dimension 3041c to the other dimension 3041d of this configuration is smaller than that of fig. 96.

The bias flow discharge 3040 can include a single bias flow aperture 3041. In other constructions, the bias flow discharge 3040 can include a plurality of elongated bias flow holes 3041.

For example, a frame 3020 of a nasal interface 3000 having a plurality of elongated deflection holes 3041 is shown in fig. 122. The plurality of elongated bias flow holes 3041 may not be provided in the frame, but may be provided elsewhere in the nasal interface 3000, such as in the interface body 3010.

In some constructions, the plurality of elongated offset holes 3041 can be arranged substantially parallel to one another. The plurality of elongated flow deflecting holes 3041 may be substantially straight in one plane and optionally in more than one plane and may be substantially parallel to each other. Alternatively, the plurality of elongated bias flow holes 3041 may include at least one bend and may extend substantially parallel to each other. For example, the plurality of elongated bias flow holes 3041 can include a serpentine shape. In other constructions, the plurality of elongated flow deflecting holes 3041 may not be arranged substantially parallel to one another.

For example, referring to fig. 86, 88, 89-91, and 94, the bias flow vent can include a diffuser 3050 to diffuse the gas flowing through the one or more elongated bias flow holes 3041.

In a frame configuration having a recess 3042, a diffuser 3050 may be disposed in the recess 3042. When the recess 3042 is in the front of the frame 3020, the diffuser 3050 may be in the front of the frame 3020. When the recess 3042 is in the back of the frame 3020, the diffuser 3050 may be in the back of the frame 3020.

In some constructions, the frame may not include the recess 3042. In this case, the diffuser 3050 may be in front of the one or more elongated bias holes 3041 or behind the one or more elongated bias holes 3041, rather than in the recess.

In some constructions, a plurality of diffusers 3050 can be disposed on both sides of the one or more elongated bias holes 3041. One diffuser 3050 may be on a rear side of the one or more elongated bias holes 3041, and one diffuser 3050 may be disposed on a front side of the one or more elongated bias holes 3041.

The diffuser 3050 may aid in noise attenuation and/or usability. The diffuser 3050 reduces the flow rate of the air flow between the nasal interface 3000 and the surrounding environment through the elongated deflector hole 3041, thereby reducing noise generation and avoiding the generation of jets that may cause discomfort to the user and/or others, for example, if the jet impinges on the face of a bed partner.

The diffuser 3050 may comprise a single diffuser material having a suitable thickness. For example, in one non-limiting configuration, the diffuser material may be about 2mm to about 4mm thick. Thicker or multiple diffuser materials may be used if additional noise attenuation is desired.

The diffuser 3050 may be adhesively positioned or, for example, clamped in the recess 3042.

The diffuser 3050 may be formed of any suitable material disclosed herein. For example, the diffuser material may comprise polyester or polyethylene terephthalate (PET).

The diffuser 3050 may additionally filter the gases exiting the nasal interface 3000.

In the illustrated construction, the gas inlet 3021 and the first and second nasal delivery elements 3011, 3012 are in fluid communication with the gas flow passage 3025 of the interface body 3010 to deliver breathing gas from the gas inlet 3021 through the first and second nasal delivery elements 3011, 3012. In this configuration, gas may be delivered from the gas inlet 3021, into the gas flow channel 3025, and from the gas flow channel 3025 into the first and second nasal delivery elements 3011, 3012.

As described elsewhere herein, the interface body 3010 may include a bypass restrictor 3030 to provide a pressure drop through the gas flow passage 3025, as shown, for example, in fig. 116-118. Or, as shown for example in fig. 109-115, the interface body 3210 may include a first nasal delivery element 3211 configured to seal with a first naris of a patient, a second nasal delivery element 3212 configured to seal with a second naris of the patient, a first gas flow path 3225a in fluid communication with the first nasal delivery element 3211, a second gas flow path 3225b in fluid communication with the second nasal delivery element 3212, a wall 3230 within the interface body 3210 pneumatically isolating the first gas flow path 3225a and the second gas flow path 3225b, and a gas inlet 3221 for delivering respiratory gas to the first gas flow path 3225 a.

In this configuration, a bias flow discharge port 3240, including one or more elongated bias flow holes 3241, is in fluid communication with second gas flow channel 3225 b. In this configuration, gas will not flow directly from the gas inlet 3221 through the gas flow channel into the second nasal delivery element 3212. However, gas may flow from the gas inlet 3221 into the first gas flow channel 3225a, through the first nasal delivery element 3211, through the patient's upper airway (e.g., during breath-hold), through the second nasal delivery element 3212, into the second gas flow channel 3225b, and out to the ambient environment through the bias flow discharge port 3240.

Referring to fig. 97, 98, 99 and 100, the nasal interface 3000 includes an interface body 3010 including a first nasal delivery element 3011 configured to seal with a first nostril of a patient and a second nasal delivery element 3012 configured to seal with a second nostril of the patient. The nasal interface 3000 includes a gas inlet 3021 for delivering breathing gas into the nasal interface 3000. The nasal interface 3000 includes a bias flow vent 3040 for gas to flow out of the nasal interface 3000. The inner surface of the gas inlet 3021 transitions to the inner surface of the nasal interface at the outlet 3021b, wherein the outlet 3021b comprises a perimeter 3021d having portions of different radius from each other, wherein the portion 3021c of the perimeter 3021d adjacent to the bias flow discharge port 3040 has a radius that is greater than the radius of the other portions of the perimeter.

The larger radius of portion 3021c may reduce noise. The larger radius may provide a smooth diversion of the airflow toward the downstream second nasal delivery element 3212 and/or the bias flow discharge 3140. Other portions of the perimeter 3021d may have a radius, but the radius of these other portions may be smaller than the radius of the portion 3021c adjacent the bias flow discharge port 3040.

In the configuration shown in fig. 97 and 99, the radius of the peripheral portion 3021c closest to the bias flow discharge port 3040 is larger than the radius of both the peripheral opposing outer portion and the peripheral two portions between the peripheral portion 3021c and the peripheral opposing outer portion.

The perimeter portion 3021c can be larger in size than the width dimension 3041b of the elongated flow aperture 3041. That is, the portion 3021c may extend beyond the upper edge and the lower edge of the elongated flow deflecting aperture 3041. Or the size of the peripheral portion 3021c may substantially correspond to the width dimension 3041b of the elongated flow aperture 3041.

In some constructions, the outlet 3021b has a non-circular shape.

The gas inlet 3021 may have a non-circular shape to reduce the size of the gas inlet on the patient's face. In particular, as described above for nasal interface 2900, the vertical dimension of gas inlet 3021 may be less than the lateral or horizontal dimension of gas inlet 3021.

In some constructions, the bias flow drain 3040 includes one or more elongated bias flow holes 3041. The one or more elongated offset holes 3041 may be as described above or herein. Or the bias flow drain 3040 may include a configuration that does not include one or more elongated bias flow holes. In this configuration, the aperture may extend from the inner surface to the outer surface, but may not be elongated.

In some configurations, the gas inlet 3021 is positioned closer to the first nasal delivery element 3011 than to the second nasal delivery element 3012. Or the gas inlet 3021 may be positioned elsewhere in the nasal interface 3000. For example, the gas inlet 3021 may be centrally located on the nasal interface 3000 or may be located in any other location as described herein. The nasal interface 3000 may include a deflector to direct airflow toward the first nasal delivery element 3011.

In some configurations, the bias flow discharge port 3040 is positioned closer to the second nasal delivery element 3012 than to the first nasal delivery element 3011. Or the bias flow drain 3040 may be positioned elsewhere in the nasal interface 3000. For example, if the gas inlet 3021 is centrally located on the nasal interface 3000, the bias flow discharge port 3040 may be provided on one or both sides of the gas inlet 3021. In the case where bias flow discharge ports 3040 are provided on both sides of the gas inlet 3021, one side of the perimeter of the gas inlet 3021 adjacent to the first or first set of bias flow discharge ports 3040 may have a larger radius than the other side of the perimeter of the gas inlet 3021 adjacent to the other second or second set of bias flow discharge ports 3040, such that the flow characteristics (e.g., flow rate) of the gas toward the first or first set of bias flow discharge ports 3040 may be different from the flow characteristics of the gas toward the second or second set of bias flow discharge ports 3040. Or portions of the perimeter of the gas inlet 3021 adjacent to the first or first set and the second or second set of bias flow discharge ports 3040 may have the same or similar radii that are greater than the radii of other portions of the perimeter of the gas inlet 3021.

Fig. 106-108 illustrate another exemplary configuration nasal interface 3100 and its components.

Unless described below, features, functions, and options for the nasal interface 3100 are the same as those described for the nasal interface 3000, and like reference numerals denote like parts, except that 100 is added.

The nasal interface 3100 includes an interface body 3110 that includes a first nasal delivery element 3111 configured to seal with a first nostril of a patient and a second nasal delivery element 3112 configured to seal with a second nostril of the patient.

In some constructions, the nasal interface 3100 includes an interface body 3110 and a frame 3120 or gas manifold that cooperate to define a gas flow channel 3125 therein. In some alternative constructions, the gas flow channel 3125 may alternatively be defined substantially or solely by the interface body 3110, and the frame 3120 or gas manifold may not be provided.

The nasal interface 3100 comprises a gas inlet 3121 for delivering respiratory gas into the nasal interface 3100, wherein the gas inlet 3121 is positioned closer to the first nasal delivery element 3111 than to the second nasal delivery element 3112.

The gas inlet 3121 and the nasal delivery elements 3111, 3112 are in fluid communication with the gas flow channel 3125 or gas chamber of the interface body 3110 to deliver breathing gas from the gas inlet 3121 through the nasal delivery elements 3111, 3112.

The nasal interface 3100 includes a bias flow vent 3140, schematically illustrated in fig. 107, for flowing gas out of the nasal interface 3100, the bias flow vent 3140 being positioned closer to the second nasal delivery element 3112 than the first nasal delivery element 3111.

The inner surface of the interface body 3110 includes a protrusion 3113 extending from the base 3111b of the first nasal delivery element 3111 towards the gas inlet 3121, the protrusion 3113 extending radially outwardly as it extends towards the gas inlet 3121.

In some constructions, the protrusion 3113 includes a ring surrounding the base 3111b of the first nasal delivery element 3111. The protrusion 3113 may substantially match the shape of the base 3111b of the first nasal delivery element 3111.

The protrusion 3113 defines a protruding gas flow channel 3113a, and the protruding gas flow channel 3113a has a larger cross-sectional area at its end region closer to the gas inlet 3121 than at its region closer to the first nasal delivery element 3111.

The protrusions 3113 form a funnel to direct a gas flow from the gas inlet 3121 into the first nasal delivery element 3111. This also helps to maximize the amount of gas flowing from the gas inlet 3021 that is captured and delivered into the first nasal delivery element 3111.

In some constructions, the protrusion 3113 is integrally formed with the interface body 3110. Alternatively, the protrusion 3113 may be formed separately from the interface body 3110. For example, the protrusion 3113 may include an insert attached (removable or non-removable) to the interface body 3110.

The protrusion 3113 may include a single continuous component that extends around the base of the first nasal delivery element 3111. Alternatively, the protrusion 3113 may include a plurality of protrusions. The plurality of protrusions may form a substantially continuous protrusion around the base 3111b of the first nasal delivery element 3111. Alternatively, the plurality of protrusions may form one or more discontinuous protrusions around at least a portion of the base 3111b of the first nasal delivery element 3111.

In some constructions, the inner surface of the interface body 3110 includes a second protrusion 3114 extending from the base 3112b of the second nasal delivery element 3112 toward the bias flow discharge 3140.

The second protrusion 3114 may extend radially outward as it extends from the base 3112b of the second nasal delivery element 3112 toward the bias flow discharge 3140. Alternatively, the second protrusion 3114 may have a different configuration, such as substantially parallel walls or tapered as it extends from the base 3112b of the second nasal delivery element 3112 toward the bias flow discharge 3140.

Fig. 109-115 illustrate an exemplary configuration of an alternative nasal interface 3200 and its components.

Unless described below, features, functions, and options of the nasal interface 3200 are the same as those described for the nasal interface 3000, and like reference numerals denote like parts, except that 200 is added.

The nasal interface 3200 includes an interface body 3210 that includes a first nasal delivery element 3211 configured to seal with a first nostril of a patient and a second nasal delivery element 3212 configured to seal with a second nostril of the patient.

In some constructions, the nasal interface 3200 includes an interface body 3210 and a frame 3220 or gas manifold that cooperate to define a gas flow channel 3225 therein. In some alternative constructions, the gas flow channels 3225 may instead be defined substantially or solely by the interface body 3210, and no frame 3220 or gas manifold may be provided.

The nasal interface 3200 includes a first gas flow channel 3225a in fluid communication with the first nasal delivery element 3211, a second gas flow channel 3225b in fluid communication with the second nasal delivery element 3212, and a wall 3230 within the interface body 3210 pneumatically isolating the first gas flow channel 3225a and the second gas flow channel 3225 b.

Nasal interface 3200 includes a gas inlet 3221 for delivering respiratory gas to first gas flow path 3225 a. The gas inlet 3221 is in direct fluid communication with the first gas flow channel 3225 a.

The nasal interface 3200 includes a bias flow vent 3240 for gas flow out of the nasal interface 3200. The bias flow discharge port 3240 is in fluid communication with the second gas flow path 3225 b.

Bias flow drain 3240 fluidly communicates second gas flow path 3225b with ambient.

The gas inlet 3221 may be configured to direct a flow of breathing gas from the gas inlet 3221 to the first outlet 3211a of the first nasal delivery element 3211. In some constructions, at least the outlet 3221b of the gas inlet 3221 is arranged to direct the flow of breathing gas to the outlet 3211a of the first nasal delivery element 3211. In some constructions, the gas inlet 3221 can be configured to provide a substantially direct flow of gas from the gas inlet 3221 to the first outlet 3211a.

To achieve this substantially direct airflow, the outlet 3221b may be substantially aligned with and directed toward the first outlet 3211a in substantially the same manner as shown in fig. 107 for the outlet 3121a and the first outlet 3111 a.

By pneumatically isolating the first and second gas flow channels 3225a, 3225b within the interface body 3210, the nasal interface 3200 may create a unidirectional flow of gas at the patient, particularly during exhalation.

The wall 3230 is configured to cause unidirectional airflow during nasal interface use. Wall 3230 may be configured to cause unidirectional airflow during a phase of a patient's respiratory cycle.

This unidirectional airflow may create greater airway clearance than bypass restrictors (e.g., bypass restrictors for nasal interface 3300 described below).

The bias flow discharge port 3240 is located at the second gas flow path 3225b and provides resistance to gas flow from the second gas flow path 3225b to the ambient environment, thereby pressurizing the second gas flow path 3225b in use. This minimizes the amount of pressure differential between first gas flow path 3225a and second gas flow path 3225b and between first nasal delivery element 3211 and second nasal delivery element 3212, which may have an impact on patient comfort. In general, a larger pressure differential may result in a greater likelihood of discomfort to the patient.

If the bias flow vent 3240 creates a pressure of about 8cmH ₂ O in the second gas flow path 3225b, for example, when about 12cmH ₂ O delivers pressure into the nasal interface 3200, the pressure differential experienced by the patient in both nostrils will be about 4cmH ₂ O. Or if the second nasal delivery element 3212 is vented directly to the external environment rather than through the bias flow vent 3240, the pressure drop experienced by the patient at the nostrils is 12cmH ₂ O.

In some constructions, the nasal interface 3200 includes an interface body 3210 and a frame 3220, wherein the interface body 3210 includes a first nasal delivery element 3211 and a second nasal delivery element 3212, and the frame 3220 includes a gas inlet 3221 and a bias flow discharge 3240.

In one configuration, the wall 3230 may be provided by a frame 3220, as shown in fig. 113-115.

In this configuration, wall 3230 includes a protrusion extending rearward from body portion 3223 of frame 3220. The walls are configured to fill or substantially fill the recess 3213 in the body portion 3214 of the interface body 3210 to provide pneumatic isolation.

The wall 3230 may include a shape corresponding to the cross-sectional shape of the first gas flow channel 3225a, the second gas flow channel 3225b, or both the first gas flow channel 3225a and the second gas flow channel 3225 b.

In another configuration, the nasal interface 3200 may include an insert 3250 for positioning in or within the interface body 3210. The insert includes a wall 3230.

One configuration of a nasal interface with an insert 3250 is shown in fig. 109-111. The insert 3250 includes a component for receipt within the interface body 3210. When the insert 3250 is received within the interface body 3210, the wall 3230 of the insert 3250 is configured to fill or substantially fill the recess 3213 in the body portion 3214 of the interface body 3210 to provide pneumatic isolation.

Referring to fig. 111, the insert 3250 may include a wall 3230 and two wings 3231, 3232 protruding laterally outward from the wall 3230 in opposite directions from one another. In the illustrated configuration, the wings 3231, 3232 project laterally outwardly from the rear of the wall 3230 in opposite directions from each other, but they may alternatively project outwardly from a different portion of the wall 3230.

The wings 3231, 3232 are configured to contact an inner surface of the interface body 3210 proximate the base portions 3211b, 3212b of the first and second nasal delivery elements 3211, 3212.

In the illustrated construction, the wings 3231, 3232 each include a ring member having a size at least equal to or greater than the size of the bases 3211b, 3212b of the first and second nasal delivery elements 3211, 3212.

One or both of the wings 3231, 3232 may have a configuration similar to the protrusions 3113, 3114, wherein the apertures formed on the ring members extend radially outwardly as they extend from the respective nasal delivery elements 3211, 3212 towards the gas inlet 3121 or bias flow discharge 3240.

The wings 3231, 3232 can be configured to form a seal against an inner surface of the interface body 3210. The wings 3231, 3232 may support a portion of the interface body 3210. The wings 3231, 3232 may resist deformation of the interface body 3210, for example, when the user wears the nasal interface 3200 and actuates the first and second nasal delivery elements 3211, 3212 in a direction toward the frame 3220.

The wall 3230 may be configured to be substantially coplanar with a sagittal plane of the patient when the nasal interface 3200 is in use.

The insert 3250, interface body 3210, and/or frame 3220 may include one or more engagement features for engaging the insert 3250 in the nasal interface 3200.

In the configuration shown in fig. 109, 110, and 111, the insert 3250 includes upper and lower engagement protrusions 3234, 3235 configured to be received behind upper and lower lips 3216, 3217 of the interface body 3210. When the frame 3220 is mounted to the interface body 3210, the upper and lower portions 3231a, 3231b of the body portion 3231 of the frame 3220 are received behind the upper and lower lips 3216, 3217 of the interface body 3210 to help retain the insert 3250 in position in the interface body 3210.

The frame 3220 may include an upper recess 3231c and a lower recess 3231d to receive terminal ends of the upper lip 3216 and lower lip 3217 of the interface body 3210.

Any other suitable engagement feature may be provided. For example, the insert may be clipped or snap-fit into the interface body, one of the components may include one or more protrusions to engage with one or more protrusions or recesses on the other of the components, or the components may be engaged with one another by adhesive, bonding, overmolding, or any other suitable configuration.

In another configuration, the wall 3230 may be integrally formed with the interface body 3210. For example, the interface body including the wall may be injection molded as a single component.

The wall 3230 may be integrally formed with the frame 3220, the interface body 3210, or both the frame 3220 and the interface body 3210 (the frame 3220 forming part of the wall and the interface body 3210 forming part of the wall).

The wall 3230 may comprise the same material as the frame 3220 and/or interface body 3210. Alternatively, the wall 3230 may be formed from a material different from that of the frame 3220 and/or the interface body 3210.

The wall 3230 may have the same rigidity as the frame 3220 and/or interface body 3210. Alternatively, the wall 3230 may have a different rigidity than the frame 3220 and/or interface body 3210. For example, in some constructions, the wall 3230 may be more rigid than the interface body 3210, may have the same rigidity as the interface body 3210, or may be less rigid than the interface body 3210. As another example, in some constructions, wall 3230 may be more rigid than frame 3220, have the same rigidity as frame 3220, or may be less rigid than frame 3220.

The nasal interface 3200 may be configured such that, in use, biasing the discharge port 3240 creates a pressure in the second gas flow path 3225b to minimize a pressure differential between the pressures created in the first gas flow path 3225a and the second gas flow path 3225 a.

In some constructions, the bias flow discharge ports 3240 of any of the nasal interfaces 3200 include one or more elongated bias flow holes 3241. The one or more elongated deflection holes 3241 may be as described herein.

Fig. 116-118 illustrate exemplary configurations of alternative nasal interface 3300 and its components.

Unless described below, features, functions, and options for the nasal interface 3300 are the same as those described for the nasal interface 3200, and like reference numerals denote like parts, except that 100 is added.

The nasal interface 3300 includes an interface body 3310 that includes a first nasal delivery element 3311 configured to seal with a first nostril of a patient and a second nasal delivery element 3312 configured to seal with a second nostril of the patient.

In some constructions, the nasal interface 3300 includes an interface body 3310 and a frame 3320 or gas manifold that cooperate to define a gas flow passage 3325 therein. In some alternative constructions, the gas flow channel 3325 may instead be defined substantially or solely by the interface body 3310, and the frame 3320 or gas manifold may not be provided.

Nasal interface 3300 includes gas flow passage 3325. The gas flow channel 3325 includes a first gas flow channel portion 3325a in fluid communication with the first nasal delivery element 3311, a second gas flow channel portion 3325b in fluid communication with the second nasal delivery element 3312, and a wall 3330 between the first gas flow channel portion 3325a and the second gas flow channel portion 3325b. This configuration differs from nasal interface 3200 in that: in this configuration, the first and second gas flow passages 3325a, 3325b are not pneumatically isolated from one another within the interface body 3310. Instead, a wall gas flow passage 3336 is provided in or defined by the wall such that gas can flow directly from the first gas flow passage portion 3325a to the second gas flow passage portion 3325b through the wall gas flow passage 3336.

Nasal interface 3300 includes a gas inlet 3321 for delivering respiratory gases to gas flow passage 3325. The gas inlet 3321 is positioned closer to the first nasal delivery element 3311 than to the second nasal delivery element 3312.

The nasal interface 3300 includes a bias flow discharge port 3340 for airflow out of the nasal interface 3300. The bias flow discharge port 3340 is positioned closer to the second nasal delivery element 3312 than the first nasal delivery element 3311.

The wall 3330 and the wall gas flow channels provide bypass restrictors in the gas flow channels 3325. The bypass restrictor may provide a pressure drop between the first and second nasal delivery elements 3311, 3312 through the nasal interface 3300 when gas is delivered from the gas inlet 3331 to the first and second nasal delivery elements 3311, 3312 such that the pressure at the first nasal delivery element 3311 is higher than the pressure at the second nasal delivery element 3312.

The bypass restrictor provides a reduced cross-sectional area of a portion of the gas flow passage 3325.

In some constructions, the portion of the gas flow path is between the first nasal delivery element 3311 and the second nasal delivery element 3312 and/or adjacent to the second nasal delivery element 3312.

The bypass flow restrictor may include any of the features, functions, parameters, dimensions, or relationships with other components described herein for other bypass flow restrictors.

Although the wall gas flow channels 3336 are shown as holes in fig. 116-118, the wall gas flow channels may have any suitable configuration. For example, the wall gas flow channels 3336 may be formed as slits or gaps between two spaced apart portions of the wall 3330. Or one or more edges of the wall 3330 may include an outboard recess that provides space for airflow between the wall and the frame 3320 and/or interface body 3310.

The wall 3330 may be provided by the frame 3320, the interface body 3310, or as an insert 3350, as described above for the nasal interface 3320. For example, the wall 3330 of the frame 3220 of fig. 114 and 115 may include a wall gas flow channel 3336. In another configuration, the wall 3330 may be integrally formed with the interface body 3310. For example, the interface body 3310 including the wall 3330 may be injection molded as a single component.

The wall 3330 may be integrally formed with the frame 3320, the interface body 3310, or both the frame 3320 and the interface body 3310 (the frame 3320 forming part of the wall and the interface body 3310 forming part of the wall).

The wall 3330 may comprise the same material as the frame 3320 and/or the interface body 3310. Alternatively, the wall 3330 may be formed of a material different from the material of the frame 3320 and/or the interface body 3310.

The wall 3330 may have the same rigidity as the frame 3320 and/or the interface body 3310. Alternatively, the wall 3330 may have a different rigidity than the frame 3320 and/or the interface body 3310. For example, in some constructions, the wall 3330 may be more rigid than the interface body 3310, may have the same rigidity as the interface body 3310, or may be less rigid than the interface body 3310. As another example, in some constructions, the wall 3330 may be more rigid than the frame 3320, may have the same rigidity as the frame 3320, or may be less rigid than the frame 3320.

Fig. 119 illustrates features of side arms 3024, 3025 of a frame 3020 of a nasal interface 3000. The frame 3020 may be used with any of the nasal interfaces described herein.

The frame side arms 3024, 3025 have a thin wall thickness. As a result of the thin wall thickness, the side arms 3024, 3025 will press less into the user's face when the patient is lying on his side than when having a thicker profile. This tends to reduce discomfort and reduces marking on the patient's face. The face contacting surfaces of the side arms 3024, 3025 have a contact area that distributes the pressure created by the tension of the headgear 3500 over the user's face. In particular, the frame side arms 3024, 3025 have a height that enables the frame side arms 3024, 3025 to be rigid in the vertical direction (i.e., movement in direction C (about the Z axis) will tilt the interface body 3010), while the thinness of the frame side arms can provide flexibility in the lateral and torsional directions (directions B (about the Y axis) and a (about the a axis), respectively).

Each frame side arm 3024, 3025 may include one or more cutouts to further enhance their flexibility in directions a and B.

In the illustrated construction, the frame side arms 3024, 3025 each include a first cutout 3026, 3027 adjacent to the frame portion coupled to the interface body 3010, and further include a second cutout 3028, 3029 adjacent to the end of the frame side arm coupled to the headgear 3500.

In alternative constructions, the frame side arms 3024, 3025 may each include a single cut at any suitable location on the side arms, or may include three or more cuts.

The notches 3026, 3027, 3028, 3029 may comprise a curved configuration and may be substantially C-shaped as shown.

Figures 120 and 121 illustrate headgear 3500 for use with the nasal interface described herein.

In the illustrated construction, headgear 3500 includes an adjustment feature 3502 to enable adjustment of the length of overhead strap 3501. In particular, the overhead strap 3501 may include a male strap portion 3503 and a female strap portion 3504. The free end portion of the female tape portion 3504 includes an aperture 3505 through which the free end portion of the male tape portion 3503 passes, and the male tape portion 3503 engages the aperture 3505 to allow incremental adjustment of the total tape length.

In some constructions, the male strip portion 3503 includes a plurality of notches 3506 that engage with the apertures 3505 of the female strip portion 3504.

Headgear 3500 and adjustment features may have one or more of the features and functions described in U.S. patent 11,173,270. The contents of this specification are incorporated herein by reference in their entirety.

The front end 3508 of the headgear strap may be configured as a through-channel 3023a, 3024b (fig. 87) extending through the side arms 3023, 3024 of the frame 3020 to attach the headgear 3500 to the nasal interface 3000. The front end 3508 may also provide adjustment of the length of the headgear strap.

Headgear 3500 may include a rear or neck strap 3507. The back or neck strap 3507 may be of a fixed length or an adjustable length. The rear or neck strap 3507 may include the same adjustment features as the adjustment features 3502 of the overhead strap 3501.

Headgear 3500 may be formed from any suitable material. For example, headgear 3500 may be formed from a fabric or a suitable polymeric material, such as flame-welded neoprene.

As described above for nasal interface 100, in some configurations of nasal interfaces 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 2900, 3000, 3100, 3200, 3300, the nasal interface is configured to achieve a patient pressure of between about 2cmH ₂ O and about 30cmH ₂ O at the first outlet or first outlet portion and the second outlet or second outlet portion in use, optionally between about 2cm H ₂ O and about 25cm H ₂ O in use, optionally between about 2cm H ₂ O and about 20cm H ₂ O in use, optionally between about 2cm H ₂ O and about 15cm H ₂ O in use, optionally between about 2cm H ₂ O and about 14cm H ₂ O in use, Optionally between about 2cm H ₂ O and about 13cm H ₂ O in use, optionally between about 2cm H ₂ O and about 12cm H ₂ O in use, Optionally between about 2cmH ₂ O and about 11cmH ₂ O in use, optionally between about 2cmH ₂ O and about 10cmH ₂ O in use.

As described above for nasal interface 100, in some configurations of nasal interfaces 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 2900, 3000, 3100, 3200, 3300, the pressure differential between first outlet 1111a or first outlet portion and second outlet 1112a or second outlet portion is configured to provide an asymmetric airflow through the upper airway of the patient of at least about 1 liter per minute (lpm), optionally between about 1lpm and about 5 lpm.

The asymmetric airflow provided by the nasal interfaces 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 2900, 3000, 3100, 3200, 3300 facilitates the cleaning of CO ₂ from patient anatomical dead spaces.

The nasal interface 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 2900, 3000, 3100, 3200, 3300 disclosed herein is configured to simultaneously deliver respiratory gases from a gas inlet through an interface body to a first nostril and a second nostril of a patient in use.

In some configurations, during the exhalation phase, the airflow may leave one or both of the first naris and/or the second naris as the patient exhales. Then, when the patient inhales, some of the gas exhaled from the first nostril and/or the second nostril may enter the first nostril and/or the second nostril.

As described above, a patient interface 1 having a nasal interface 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 2900, 3000, 3100, 3200, 3300 constructed in accordance with the disclosure herein may be used in a method of delivering gas to an airway of a patient in need thereof, improving ventilation of a patient in need thereof, reducing the volume of anatomical dead space within the airway volume of a patient in need thereof, and/or treating a respiratory condition of a patient in need thereof.

A patient interface 1 comprising nasal interfaces 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 2900, 3000, 3100, 3200, 3300 of the type disclosed herein may be used in a respiratory therapy system for delivering gases to a patient.

Because patient interface 1 may include any of the nasal interfaces (or nasal interface components, such as interface bodies 2110, 2210, 2310, 2410, 2610, 2910) of the type disclosed herein, references herein and below to nasal interface 100 may alternatively be considered references to any of the other nasal interfaces 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 2900, 3000, 3100, 3200, 3300.

In some constructions, the respiratory therapy system 1000 includes a respiratory therapy device 1100 and a patient interface 1 including a nasal interface 100.

An exemplary respiratory therapy apparatus 1100 is shown in fig. 22.

Respiratory therapy apparatus 1100 includes a main housing 1101 containing an airflow generator 1011 in the form of a motor/impeller device (e.g., a blower), an optional humidifier 1012, a controller 1013, and a user interface 1014 (including, for example, a display and input devices such as buttons, touch screen, etc.).

The controller 1013 may be configured or programmed to control the operation of the device. For example, the controller may control components of the device, including, but not limited to: operating the flow generator 1011 to generate a flow of gas for delivery to a patient, operating the humidifier 1012 (if present) to humidify and/or heat the generated flow of gas, controlling the flow of oxygen into the flow generator blower, receiving user input from the user interface 1014 for reconfiguration and/or user-defined operation of the apparatus 1000, and outputting information to a user (e.g., on a display).

The user may be a patient, a healthcare professional, or any other person interested in using the device. As used herein, "airflow" may refer to any airflow that may be used in a respiratory assistance device or breathing device, such as an ambient airflow, an airflow comprising substantially 100% oxygen, an airflow comprising some combination of ambient air and oxygen, and/or the like.

The controller 1013 may be implemented as a pure hardware controller, software running on controller hardware, or software operating on other non-dedicated controller hardware of the device. Or may be implemented as any number of combinations of the foregoing embodiments.

In various forms, the controller 1013 may include a processor and memory.

It should be appreciated that the various steps of detecting, operating, sensing, comparing, enabling or disabling, triggering, pulsing, monitoring, receiving, determining, etc., performed by the controller 1013 or as part of a method of device operation may be performed autonomously, automatically, or dynamically. For example, the controller may perform these steps or various steps independently of any other input or control signals, whether as hardware, hardware and software, or internal or external system implementations. As another example, they may be performed automatically in response to one or more preceding steps or preconditions.

Where a method or control step or structural element is described as being associated with another method or control step or structural element, this will generally be understood to mean the relationship between the two features. In particular, a relationship to a method or control step may represent a prior, dependent, subsequent or general connection to the method or control step. Relationships with structural elements may represent functional relationships between the structural elements, such as to provide a particular result or a connected or coordinated operational relationship. Or a relationship with a structural element may represent a direct physical relationship between two structural elements. Further meanings of the term "associated with" or "associated with" such elements or steps are to be understood from the context where appropriate.

One end of the breathing tube 16 is coupled to an airflow outlet 1021 in the housing 1100 of the respiratory therapy device 1100. The other end of the breathing tube 16 is coupled to a nasal interface 100 having a gas manifold 120 and nasal prongs 111, 112. The connection to the nasal interface 100 may be a direct connection to the nasal interface or may be via the respiratory conduit 300 and optional filter 500.

The airflow generated by the respiratory therapy device 1100 may be humidified and delivered to the patient through the nasal interface 100 via the breathing tube 16. The breathing tube 16 may have a heater to heat the flow of air through the breathing tube to the patient. For example, the breathing tube 16 may have a heating wire 16a to heat the flow of air through the breathing tube to the patient. The heating wire 16a may be under the control of the controller 1013. The breathing tube 16a, breathing conduit 300 (when provided), and/or nasal interface 100 may be considered as part of the respiratory therapy device 1100, or alternatively, a peripheral device to the respiratory therapy device. The respiratory therapy apparatus 1100, the breathing tube 16, the respiratory conduit 300 (when provided), and the patient interface 1 including the nasal interface 100 together may form a respiratory therapy system 1000.

The controller 1013 may control the airflow generator 1011 to generate an airflow of a desired flow rate. The controller 1013 may also control the supplemental oxygen inlet to allow delivery of supplemental oxygen, the humidifier 1012 (if present) may humidify the gas stream and/or heat the gas stream to an appropriate level, and/or the like. The airflow is directed to the patient through the breathing tube 16, the breathing conduit 300, and the nasal interface 100. The controller 1013 may also control the heating elements in the humidifier 1012 and/or the heating element 16a in the patient conduit 16 to heat the gas to a desired temperature for a desired therapeutic level and/or patient comfort level. The controller 1013 may be programmed with or may determine an appropriate target temperature for the gas flow. In some configurations, the gas mixture components including supplemental oxygen and/or therapeutic administration may be provided through a supplemental oxygen inlet. The gas mixture components may include oxygen, heliox, nitrogen, nitric oxide, carbon dioxide, argon, helium, methane, sulfur hexafluoride, and combinations thereof, and/or the supplemental gas may include an aerosolized drug.

Operational sensors 1003a, 1003b, 1003c, such as flow, temperature, humidity, and/or pressure sensors, may be placed at various locations in respiratory therapy device 1100. Additional sensors (e.g., sensors 1020, 1025) may be placed at various locations on the breathing tube 16, the breathing conduit 300, and/or the nasal interface 100 (e.g., there may be a temperature sensor 1029 at or near the end of the inhalation tube). The output from the sensor may be received by the controller 1013 to assist the controller in operating the respiratory therapy apparatus 1100 in a manner that provides the appropriate therapy. In some configurations, providing a suitable treatment includes meeting a patient's peak inhalation needs. The device 1100 may have a transmitter and/or receiver 1015 to enable the controller 1013 to receive the signal 1008 from the sensor and/or control various components of the respiratory therapy device 1100, including but not limited to the airflow generator 1011, the humidifier 1012, and the heater wire 16, or accessories or peripherals associated with the respiratory therapy device 1100. Additionally or alternatively, the transmitter and/or receiver 1015 may communicate data to a remote server or enable remote control of the device 1100.

In some constructions, the respiratory therapy system 1000 includes a gas source 1011 for respiratory gas and configured to provide pressure controlled respiratory gas, a breathing tube 16 that receives pressure controlled respiratory gas, and a nasal interface.

In some configurations of respiratory therapy system 1000, nasal interface 100 includes any one or more features described herein in fluid communication with breathing tube 16 to deliver pressure-controlled breathing gas to a patient.

In some configurations of respiratory therapy system 1000, nasal interface 100 has a gas inlet 121 in fluid communication with respiratory tube 16 to deliver respiratory gas to a patient, the nasal interface comprising a first nasal delivery element 111 and a second nasal delivery element 112, wherein each of the first nasal delivery element 111 and the second nasal delivery element 112 are configured to seal with a respective nostril of the patient, wherein nasal interface 100 is configured to create a pressure differential between the first nasal delivery element 111 and the second nasal delivery element 112 when gas is delivered from gas inlet 121 to first nasal delivery element 111 and second nasal delivery element 112 such that a pressure at first nasal delivery element 111 is higher than a pressure at second nasal delivery element 112.

In some constructions of respiratory therapy systems, the nasal interface 1100 for use in respiratory therapy systems includes an interface body 1110 configured to substantially form a seal with a patient's nasal airway. The interface body 1110 is configured to deliver gas to a first naris of a patient and a second naris of the patient. The nasal interface 1100 includes a gas inlet 1121 for delivering breathing gas into the nasal interface 1100. The gas inlet 1121 is in fluid communication with the interface body 1110 to, in use, deliver breathing gas from the gas inlet 1121 through the interface body 1110 to the first naris and the second naris of the patient. The nasal interface 1100 is configured to receive an inlet gas F0 from the gas inlet 1121 and provide a first flow F1 of gas from the inlet gas F0 that is configured to be substantially provided to a first naris of a patient in use and a second flow F2 of gas that is configured to be substantially provided to a second naris of the patient in use. The nasal interface 1100 is configured to direct more of the incoming gas to the first gas flow F1 than the second gas flow F2 to create an asymmetric gas flow at the patient's nasal airway throughout the patient's respiratory cycle.

In some configurations of respiratory therapy systems, a nasal interface 1100 for use in a respiratory therapy system includes an interface body 1110 configured to substantially form a seal with a patient's nasal airway, the interface body 1110 configured to deliver gas to a patient's first nostril and a patient's second nostril. The nasal interface 1100 comprises a gas inlet 1121 for delivering respiratory gas into the nasal interface, wherein the gas inlet 1121 is in fluid communication with the interface body 1110 for delivering, in use, respiratory gas from the gas inlet 1121 through the interface body 1110 to the first and second nostrils of the patient. The nasal interface 1100 is configured to provide a greater dynamic pressure at a first naris of a patient during use and a lesser dynamic pressure at a second naris of the patient during use to create an asymmetric airflow at the nasal airway of the patient.

During the inspiratory phase of the respiratory cycle, an asymmetric airflow may be generated at the patient's nasal airway. In addition, this may also occur during the expiratory phase of the respiratory cycle. The inspiratory phase and the expiratory phase may define a respiratory cycle. In this way, an asymmetric flow of air may be provided at the patient's nasal airway through the nasal interface 1100 throughout the patient's respiratory cycle.

In some constructions, the interface body 1100 includes a first outlet 1111a or a first outlet configured to deliver gas to a first naris of a patient and includes a second outlet 1112a or a second outlet configured to deliver gas to a second naris of the patient, and wherein the nasal interface 1100 is configured to create a pressure differential between the first outlet 1111a or the first outlet and the second outlet 1112a or the second outlet when gas is delivered from the gas inlet 1221 to both the first outlet 1111a or the first outlet and the second outlet 1112a or the second outlet such that the pressure at the first outlet 1111a or the first outlet is higher than the pressure at the second outlet 1112a or the second outlet.

In some configurations, the respiratory therapy system 1000 includes a respiratory conduit 300 to receive a pressure-controlled breathing gas from the breathing tube 16, wherein the respiratory conduit 300 is in fluid communication with the breathing tube 16 and the gas inlet 121 of the nasal interface 100, 1100.

In some constructions, the respiratory therapy system 1000 includes a respiratory gas filter 500.

In some constructions, the breathing gas filter 500 is located between the heated breathing tube 16 and the breathing conduit 300. In additional or alternative configurations, and as shown, for example, in fig. 17 (b), a respiratory gas filter 500' may be located between the gas manifold 120 and the bias flow restrictor 140. For example, in the configuration of fig. 18, a respiratory gas filter 500' may be located between the exhalation gas duct 160 and the bias flow restrictor 140.

In some configurations, the respiratory therapy system includes a humidifier 1012 configured to humidify the pressure-controlled respiratory gases prior to delivery to the nasal interface 100, 1100.

In some constructions, the breathing tube 16 is a heated breathing tube and is configured to receive pressure-controlled breathing gas from the humidifier 1012.

In some configurations, the temperature of the air flow exiting the first and second nasal delivery elements 111, 112 or exiting the nasal interface 1100 for delivery to the nasal airways of the patient may be between about 31 ℃ and about 41 ℃, optionally greater than about 31 ℃ and up to about 41 ℃, optionally between about 36 ℃ and about 39 ℃, optionally about 37 ℃. For example, the temperature may be about 31 ℃, about 32 ℃, about 33 ℃, about 34 ℃, about 35 ℃, about 36 ℃, about 37 ℃, about 38 ℃, about 39 ℃, about 40 ℃, or about 41 ℃, or may be any value between any two of these values.

The respiratory therapy system may have any one or more of the features and functions described in PCT publication WO 2021/048744 and U.S. provisional applications 62/897,899 and 63/025,151 and/or PCT publication WO 2021/049954 and U.S. provisional application 62/898,464. The contents of these specifications are incorporated herein by reference in their entirety.

The patient interface 1 and nasal interface 100 used in the respiratory therapy system 1000 may have any one or more of the features and/or functions described herein with respect to the nasal interface 100 or any other nasal interface disclosed herein.

In some configurations, the nasal interface 100, patient interface 1, and/or respiratory therapy system 1000 may be used in a method of providing respiratory support to a patient.

In some constructions, a method of providing respiratory support to a patient includes:

A respiratory therapy system 1000 is provided, the respiratory therapy system comprising:

A gas source 1011 for a breathing gas configured to provide a pressure controlled breathing gas;

A breathing tube 16 for receiving a pressure controlled breathing gas; and

A nasal interface 100 having a gas inlet 121 in fluid communication with the breathing tube 16 to deliver breathing gas to a patient, the nasal interface 100 comprising a first nasal delivery element 111 and a second nasal delivery element 112;

sealing each of the first nasal delivery element 111 and the second nasal delivery element 112 to the respective nostril of the patient;

the respiratory therapy apparatus 1000 is operated to provide an airflow to the nasal interface 100; and

An asymmetric airflow is delivered from respiratory therapy apparatus 1000 at the patient's nostrils through first nasal delivery element 111 and second nasal delivery element 112.

In some configurations, the nasal delivery elements 111, 112 are in fluid communication with the gas inlet 121 through the gas flow passage 125, wherein the first nasal delivery element 111 is proximal to the gas inlet 121 and the second nasal delivery element 112 is distal to the gas inlet 121, and wherein the nasal interface comprises a bypass restrictor 130 providing a cross-sectional area a ₂ of a portion of the gas flow passage 125, wherein each of the first nasal delivery element 111 and the second nasal delivery element 112 comprises an internal cross-sectional area a ₃、A₄, wherein the internal cross-sectional areas together provide a combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and wherein the cross-sectional area a ₂ of the portion of the gas flow passage 125 is greater than 0 to about 1.5 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 1, optionally up to about 2/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and wherein the method includes providing a pressure of 4cmH ₂ O to the gas inlet 121 such that there is 20lpm of bias flow through the bias flow restrictor 140.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 1, optionally up to about 2/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and wherein the method includes providing a pressure of 8cmH ₂ O to the gas inlet 121 such that there is 32lpm of bias flow through the bias flow restrictor 140.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 2/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and wherein the method comprises providing a pressure of 4cmH ₂ O to the gas inlet 121 such that there is a bias flow of 20lpm through the bias flow restrictor 140, or wherein the method comprises providing a pressure of 8cmH ₂ O to the gas inlet 121 such that there is a bias flow of 32lpm through the bias flow restrictor 140, or wherein the method comprises providing a pressure of 12cmH ₂ O to the gas inlet 121 such that there is a bias flow of 41lpm through the bias flow restrictor 140, or wherein the method comprises providing a pressure of 16cmH ₂ O to the gas inlet 121 such that there is a bias flow of 48lpm through the bias flow restrictor 140, or wherein the method comprises providing a pressure of 20cmH ₂ O to the gas inlet 121 such that there is a bias flow of 53lpm through the bias flow restrictor 140.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 2/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and wherein the method includes providing a pressure of 8cmH ₂ O to the gas inlet 121 such that there is a bias flow of 32lpm or more through the bias flow restrictor 140.

In some constructions, the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 1/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and wherein the method includes providing a pressure of 8cmH ₂ O to the gas inlet 121 such that there is a bias flow of 32lpm or more through the bias flow restrictor 140, or wherein the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 2/5 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and wherein the method includes providing a pressure of 12cmH ₂ O to the gas inlet 121 such that there is a bias flow of 41lpm or more through the bias flow restrictor 140, or wherein the cross-sectional area a ₂ of the portion of the gas flow channel 125 is up to about 2/3 times the combined cross-sectional area a ₃+A₄ of the nasal delivery elements 111, 112, and wherein the method includes providing a pressure of 16cmH ₂ O to the gas inlet such that there is a bias flow of 48lpm or more through the bias flow restrictor 140.

In some constructions, the temperature of the air stream exiting the first and second nasal delivery elements 111, 112 is between about 31 ℃ and about 41 ℃, optionally greater than 31 ℃ and up to about 41 ℃, optionally between about 36 ℃ and about 39 ℃, optionally about 37 ℃.

providing a respiratory therapy system 1000 comprising:

A breathing tube 16 for receiving a pressure controlled breathing gas; and

A nasal interface 1100 in fluid communication with the breathing tube 16 to deliver breathing gas to a patient;

sealing the nasal interface 1100 with the patient's nasal airway;

Operating respiratory therapy apparatus 1000 to provide an airflow to nasal interface 1100; and

The ingress gas is received at the gas inlet 1221 of the nasal interface and an asymmetric flow of gas is generated at the patient's nasal airway.

The nasal interface may be any of the nasal interfaces 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 2900, 3000, 3100, 3200, 3300 disclosed herein.

In some constructions, the system is configured to deliver gas through the nasal interface 100, 1100 at a relative humidity of up to 100%.

In some configurations, the system is configured to deliver gas through the nasal interface 100, 1100 at a relative humidity of between about 14mg/l to about 34 mg/l.

In some configurations, the temperature of the airflow exiting the first and second nasal delivery elements 111, 112 and/or exiting the nasal interface 1100 for delivery to the nostrils of the patient is between about 16 ℃ and about 32 ℃.

In some configurations, the system is configured to deliver gas through the nasal interface 100, 1100 at an absolute humidity of greater than about 33 mg/l. In some configurations, the system is configured to deliver gas through the nasal interface 100 at an absolute humidity of up to about 44 mg/l.

In some configurations, the system is configured to deliver gas through the nasal interface 100, 1100 at an absolute humidity of up to about 54 mg/l.

In some configurations, the temperature of the airflow exiting the first and second nasal delivery elements 111, 112 and/or exiting the nasal interface 1100 to be delivered to the nostrils of the patient is up to about 41 ℃.

The patient interface 1 and nasal interface 100, 1100 used in the method may have any one or more of the features and/or functions described herein for nasal interface 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 2900, 3000, 3100, 3200, 3300.

The respiratory therapy system 1000 used in the method may have any one or more of the features and/or functions described herein with respect to the respiratory therapy system 1000.

In use of the patient interface 1 and nasal interface 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 2900, 3000, 3100, 3200, 3300 of the present disclosure for CPAP-type therapy, the CPAP-type therapy may provide one or more of the following compared to high flow therapy: quieter treatment, increased treatment pressure, easier detection of respiratory rate, nasal interface detachment and/or leakage (due to pressure control).

The nasal interfaces 100, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 2700, 2800, 2900, 3000, 3100, 3200, 3300 disclosed herein may be used in a healthcare facility, a home environment, an emergency vehicle, or any other suitable environment. Thus, reference herein to a "patient" should be interpreted as any suitable subject to which a nasal interface is used or to which a nasal interface is used.

Although the present disclosure has been described in terms of certain embodiments, other embodiments that are apparent to one of ordinary skill in the art are also within the scope of the present disclosure. Accordingly, various changes and modifications may be made without departing from the spirit and scope of the disclosure. For example, the various components may be repositioned as desired. Features from any of the embodiments may be combined with one another and/or a device may include one, more, or all of the features of the embodiments described above. Furthermore, not all features, aspects, and advantages are necessary for practicing the present disclosure. Accordingly, the scope of the present disclosure should be limited only by the attached claims.

The clause:

additional embodiments are included in the following clauses or numbering statements.

Clause 1, a nasal interface, comprising:

Clause 2, the nasal interface of clause 1, wherein the end of the portion adjacent the gas flow passage is offset from the midline plane by a distance of about 40mm, optionally between about 10mm and about 40 mm.

Clause 3, the nasal interface of clause 1 or 2, wherein the portion is obliquely angled between about 10 degrees and about 70 degrees relative to the midline plane at greater than 0 degrees and up to about 70 degrees, optionally relative to the midline plane.

The nasal interface of any one of clauses 4, 1-3, wherein the nasal delivery element comprises a first nasal delivery element, wherein the interface body comprises a second nasal delivery element configured to seal with a respective nostril of the patient, wherein the second nasal delivery element is in fluid communication with the gas inlet via the gas flow path, and wherein the first and second nasal delivery elements each comprise a base and an outlet.

Clause 5, the nasal interface of clause 4, wherein the portion is at an angle greater than 0 degrees and up to about 40 degrees relative to a second plane extending through the first and second nasal delivery elements from the base to the outlet of the first and second nasal delivery elements.

Clause 6, the nasal interface of clause 1, wherein the gas inlet comprises an opening into the gas flow passage of the interface body, and wherein the opening is configured to direct the flow of inlet gas from the gas inlet toward the base of the nasal delivery element.

Clause 7, the nasal interface of clauses 4 or 5, wherein the gas inlet comprises an opening into the gas flow passage of the interface body, and wherein the opening is configured to direct more of the incoming gas flow toward the base of the first nasal delivery element than toward the base of the second nasal delivery element.

Clause 8, the nasal interface of clause 4 or 5, wherein the gas inlet comprises an opening into the gas flow passage of the interface body, and wherein the opening is configured to direct the flow of inlet gas toward a chamber wall between the base of the first nasal delivery element and the base of the second nasal delivery element.

The nasal interface of any one of clauses 9, 1-7, wherein the interface body comprises a first interface body side arm and a second interface body side arm, wherein the first interface body side arm and the second interface body side arm each comprise an unsealed lumen to enhance the flexibility of the first interface body side arm and the second interface body side arm.

Clause 10, the nasal interface body of clause 9, wherein each interface body side arm comprises a patient proximal wall configured to contact, in use, a patient cheek and a patient distal wall configured to be spaced apart, in use, from the patient cheek, wherein the patient proximal wall is spaced apart from the patient distal wall with an unsealed lumen therebetween.

The nasal interface of any one of clauses 11-10, wherein the interface body comprises first and second interface body side arms, the patient interface comprising a frame having first and second frame side arms, wherein the first and second interface body side arms each comprise a through-channel such that a corresponding one of the first and second frame side arms can extend through the through-channel to couple the first and second frame side arms with the first and second interface body side arms, wherein when the first and second frame side arms are coupled with the first and second interface body side arms, proximal portions of the first and second interface body side arms are located behind proximal portions of the first and second frame side arms to be positioned between the patient's face and proximal portions of the first and second frame side arms in use.

Clause 12, the nasal interface of clause 11, wherein the interface body comprises a softer material than the frame comprising a more rigid material.

Clause 13, the nasal interface of clause 11 or 12, wherein the first and second interface body side arms each comprise respective compliant cheek portions.

The nasal interface of any one of clauses 14, 11-13, wherein each through passage is positioned adjacent an outer end of a respective interface body side arm.

The nasal interface of any one of clauses 15, 11-14, wherein each through passage comprises a hole or slit.

The nasal interface of any one of clauses 16, 1-15, wherein the nasal interface is configured to create an asymmetric airflow at the patient's nostrils in use.

The nasal interface of clause 17, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the first nasal delivery element is proximate to the gas inlet and the second nasal delivery element is distal to the gas inlet, wherein the nasal interface is configured to receive an ingress gas from the gas inlet and provide a first flow of gas from the ingress gas configured to be substantially provided to a first nostril of the patient in use and a second flow of gas configured to be substantially provided to a second nostril of the patient in use, and the nasal interface is configured to direct more ingress gas to the first flow of gas than the second flow of gas to create an asymmetric flow of gas at the patient's nasal airway throughout the respiratory cycle of the patient.

Clause 18, the nasal interface of clauses 16 or 17, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface is configured to provide, in use, a greater dynamic pressure at the first nostril of the patient and, in use, a lesser dynamic pressure at the second nostril of the patient to create an asymmetric flow of gas at the nasal airway of the patient throughout the respiratory cycle of the patient.

The nasal interface of any one of clauses 19, 16-18, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface comprises a split to unequally divide the flow of gas from the gas inlet into a first flow of gas configured to be substantially provided to the first nasal delivery element and a second flow of gas configured to be substantially provided to the second nasal delivery element, wherein the first flow of gas is configured to be greater than the flow of gas delivered along the second flow of gas to create an asymmetric flow of gas at the nasal airway of the patient throughout the respiratory cycle of the patient.

The nasal interface of any one of clauses 20, 16-19, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface comprises a bypass restrictor to provide a pressure drop across the nasal interface between the first nasal delivery element and the second nasal delivery element when gas is delivered from the gas inlet to the first nasal delivery element and the second nasal delivery element such that the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element, and wherein the nasal interface comprises a bias flow restrictor for the gas flow out of the nasal interface.

Clause 21, the nasal interface of clause 20, wherein the pressure drop across the interface body is such that when there is a flow of gas from the gas inlet to the first nasal delivery element and the second nasal delivery element, the flow of gas from the gas inlet to the first nasal delivery element is greater than the flow of gas from the gas inlet to the second nasal delivery element.

Clause 22, the nasal delivery element of any of clauses 16-21, wherein the nasal delivery element comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface is configured to create a pressure differential between the first nasal delivery element and the second nasal delivery element when gas is delivered from the gas inlet to both the first nasal delivery element and the second nasal delivery element such that the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element.

Clause 23, the nasal interface of any of clauses 16-22, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface comprises at least one gas flow restrictor that restricts a flow of gas through the nasal interface such that when gas is delivered from the gas inlet to the first nasal delivery element and the second nasal delivery element, a pressure at the first nasal delivery element is higher than a pressure at the second nasal delivery element.

The nasal interface of any one of clauses 24, 16-23, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the first nasal delivery element is proximal to the gas inlet and the second nasal delivery element is distal to the gas inlet, wherein the nasal interface comprises a bypass restrictor providing a cross-sectional area of a portion of the gas flow path, wherein the first nasal delivery element and the second nasal delivery element each comprise an internal cross-sectional area, wherein the internal cross-sectional areas together provide a combination of the first nasal delivery element and the second nasal delivery element, and wherein the cross-sectional area of the portion of the gas flow path is greater than 0 to about 1.5 times the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element.

The nasal interface of any one of clauses 25, 16-24, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the first nasal delivery element is proximal to the gas inlet and the second nasal delivery element is distal to the gas inlet,

Clause 26, a nasal interface, comprising:

The nasal interface of clause 27, 26, wherein the interface body comprises a flex region, wherein the plurality of windings are located between the flex region and the outlet of the nasal delivery element.

Clause 28, the nasal interface of clause 27, wherein the flex region extends around less than the entire perimeter of the nasal delivery element at or near the base of the nasal delivery element.

Clause 29, the nasal interface of clause 28, wherein the flex region extends around at least the anterior, posterior, and laterally inward portions of the perimeter of the nasal delivery element.

The nasal interface of any one of clauses 30, 26-29, wherein the nasal interface comprises a frame, wherein the interface body comprises a material softer than the frame comprising a more rigid material, and wherein a portion of the frame is in contact with the interface body portion adjacent the flex region to reduce or inhibit flexing of the interface body portion adjacent the flex region.

The nasal interface of any one of clauses 31, 26-30, wherein the cross-sectional shape of the coiled portion corresponds to the cross-sectional shape of the base of the outlet portion of the nasal delivery element.

The nasal interface of any one of clauses 32, 26-31, wherein the gas inlet comprises an opening into the gas flow passage of the interface body, and wherein the opening is configured to direct the flow of inlet gas from the gas inlet toward the base of the nasal delivery element.

The nasal interface of any one of clauses 33, 26-32, wherein the nasal delivery element comprises a first nasal delivery element, wherein the interface body comprises a second nasal delivery element configured to seal with a respective nostril of the patient, wherein the second nasal delivery element is in fluid communication with the gas inlet via the gas flow path, and wherein the first and second nasal delivery elements each comprise a base and an outlet.

Clause 34, the nasal interface of clause 33, wherein the first and second nasal delivery elements each comprise a plurality of convolutions forming respective bellows portions between the gas flow passage and the outlet of the respective nasal delivery element.

The nasal interface of clause 35, clause 34, wherein the interface body comprises at least one flex region, wherein the plurality of windings of each nasal delivery element are located between the at least one flex region and the outlet of the respective nasal delivery element.

The nasal interface of clause 36, 35, wherein the at least one flex region comprises two flex regions, wherein the plurality of windings of each nasal delivery element are located between a respective one of the two flex regions and an outlet of the respective nasal delivery element.

Clause 37, the nasal interface of clauses 35 or 36, wherein the at least one flex region extends around less than the entire perimeter of each nasal delivery element at or near the base of each nasal delivery element.

Clause 38, the nasal interface of clause 37, wherein the at least one flex region extends around at least the anterior, posterior, and lateral portions of the perimeter of each nasal delivery element.

Clause 39, the nasal interface of any of clauses 35-38, wherein the nasal interface comprises a frame, wherein the interface body comprises a material softer than the frame comprising a more rigid material, and wherein a portion of the frame is in contact with the interface body portion adjacent the at least one flex region to reduce or inhibit flexing of the interface body portion adjacent the at least one flex region.

The nasal interface of any one of clauses 40, 34-39, wherein the cross-sectional shape of the coiled portion corresponds to the cross-sectional shape of the base of the outlet portion of the respective nasal delivery element.

The nasal interface of any one of clauses 41, 26-40, wherein the interface body comprises a first interface body side arm and a second interface body side arm, wherein the first interface body side arm and the second interface body side arm each comprise an unsealed lumen to enhance the flexibility of the first interface body side arm and the second interface body side arm.

Clause 42, the nasal interface body of clause 41, wherein each interface body side arm comprises a patient proximal wall configured to contact, in use, a patient cheek and a patient distal wall configured to be spaced apart, in use, from the patient cheek, wherein the patient proximal wall is spaced apart from the patient distal wall with an unsealed lumen therebetween.

The nasal interface of any one of clauses 43, 26-42, wherein the interface body comprises first and second interface body side arms, the patient interface comprising a frame having first and second frame side arms, wherein the first and second interface body side arms each comprise a through-channel to enable a respective one of the first and second frame side arms to extend through the through-channel to couple the first and second frame side arms with the first and second interface body side arms, wherein when the first and second frame side arms are coupled with the first and second interface body side arms, proximal portions of the first and second interface body side arms are positioned behind proximal portions of the first and second frame side arms for positioning between the patient's face and proximal portions of the first and second frame side arms in use.

Clause 44, the nasal interface of clause 43, wherein the interface body comprises a softer material than the frame comprising a more rigid material.

Clause 45, the nasal interface of clause 43 or 44, wherein the first and second interface body side arms each comprise respective compliant cheek portions.

The nasal interface of any one of clauses 46, 43-45, wherein each through passage is positioned adjacent an outer end of a respective interface body side arm.

The nasal interface of any one of clauses 47, 43-46, wherein each through passage comprises a hole or slit.

The nasal interface of any one of clauses 48, 26-47, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the first nasal delivery element is proximal to the gas inlet and the second nasal delivery element is distal to the gas inlet, wherein the nasal interface is configured to receive an ingress gas from the gas inlet and provide a first flow of gas from the ingress gas that is configured to be substantially provided to the first nostril of the patient in use and a second flow of gas that is configured to be substantially provided to the second nostril of the patient in use, and the nasal interface is configured to direct more ingress gas to the first flow of gas than the second flow of gas to create an asymmetric flow at the nasal airway of the patient throughout the respiratory cycle of the patient.

Clause 49, the nasal interface of any of clauses 26-48, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface is configured to provide a greater dynamic pressure at the first nostril of the patient in use and a lesser dynamic pressure at the second nostril of the patient in use to create an asymmetric gas flow at the nasal airway of the patient throughout the respiratory cycle of the patient.

The nasal interface of any one of clauses 50, 26-49, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface comprises a split to unequally divide the flow of gas from the gas inlet into a first flow of gas configured to be substantially provided to the first nasal delivery element and a second flow of gas configured to be substantially provided to the second nasal delivery element, wherein the first flow of gas is configured to deliver more gas flow along the first flow than along the second flow of gas to create an asymmetric flow of gas at the nasal airway of the patient throughout the respiratory cycle of the patient.

Clause 51, the nasal interface of any of clauses 26-50, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface comprises a bypass restrictor to provide a pressure drop across the nasal interface between the first nasal delivery element and the second nasal delivery element when gas is delivered from the gas inlet to the first nasal delivery element and the second nasal delivery element such that the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element, and wherein the nasal interface comprises a bias flow restrictor for the gas flow out of the nasal interface.

Clause 52, the nasal interface of clause 51, wherein the pressure drop across the interface body is such that when there is a flow of gas from the gas inlet to the first nasal delivery element and the second nasal delivery element, the flow of gas from the gas inlet to the first nasal delivery element is greater than the flow of gas from the gas inlet to the second nasal delivery element.

Clause 53, the nasal delivery element of any of clauses 26-52, wherein the nasal delivery element comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface is configured to create a pressure differential between the first nasal delivery element and the second nasal delivery element when gas is delivered from the gas inlet to both the first nasal delivery element and the second nasal delivery element such that the pressure at the first nasal delivery element is higher than the pressure at the second nasal delivery element.

Clause 54, the nasal interface of any of clauses 26-53, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the nasal interface comprises at least one gas flow restrictor for restricting a flow of gas through the nasal interface such that when gas is delivered from the gas inlet to the first nasal delivery element and the second nasal delivery element, a pressure at the first nasal delivery element is higher than a pressure at the second nasal delivery element.

Clause 55, the nasal interface of any of clauses 26-54, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the first nasal delivery element is proximal to the gas inlet and the second nasal delivery element is distal to the gas inlet, wherein the nasal interface comprises a bypass restrictor providing a cross-sectional area of a portion of the gas flow path, wherein the first nasal delivery element and the second nasal delivery element each comprise an internal cross-sectional area, wherein the internal cross-sectional areas together provide a combination of the first nasal delivery element and the second nasal delivery element, and wherein the cross-sectional area of the portion of the gas flow path is greater than 0 to about 1.5 times the combined cross-sectional area of the first nasal delivery element and the second nasal delivery element.

Clause 56, the nasal interface of any of clauses 26-55, wherein the nasal interface comprises a first nasal delivery element and a second nasal delivery element, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient, wherein the first nasal delivery element and the second nasal delivery element are in fluid communication with the gas inlet via the gas flow path, wherein the first nasal delivery element is proximal to the gas inlet and the second nasal delivery element is distal to the gas inlet,

Clause 57, a nasal interface, comprising:

A frame configured to engage with the interface body,

Clause 58, the nasal interface of clause 57, wherein the interface body comprises a portion of the bias flow vent.

Clause 59, the nasal interface of clause 57 or 58, wherein the frame comprises a portion of the bias flow vent.

Clause 60, the nasal interface of clause 59, wherein the interface body comprises a first portion of the bias flow vent and the frame comprises a second portion of the bias flow vent.

Clause 61, the nasal interface of any of clauses 57-60, wherein the portion biasing the discharge port comprises a flow passage.

The nasal interface of any one of clauses 62, 57-61, wherein the nasal interface comprises a plurality of bias flow vents.

Clause 63, the nasal interface of clause 62, wherein the bias flow vents are arranged in at least one array around a portion of the nasal interface.

Clause 64, the nasal interface of clause 63, wherein the at least one array is configured to direct the gas from the nasal interface in a divergent pattern.

Clause 65, the nasal interface of clause 64, wherein the divergent mode comprises an airflow at least partially laterally outward from the interface body and/or from the frame.

Clause 66, the nasal interface of clauses 64 or 65, wherein the divergent mode comprises an air flow at least partially upward and/or downward from the interface body and/or from the frame.

Clause 67, the nasal interface of any of clauses 64-66, wherein the divergent mode is at least substantially conical.

The nasal interface of any one of clauses 68, 57-67, wherein the interface body comprises a central interface body portion, and wherein the frame comprises a central frame body portion, wherein the central interface body portion and the central frame body portion are configured to engage one another to define a gas flow path for delivering, in use, breathing gas from the gas inlet through the interface body to the first nostril of the patient and the second nostril of the patient.

Clause 69, the nasal interface of clause 68, wherein the central frame body portion comprises a gas inlet.

Clause 70, the nasal interface of clause 69, wherein the gas inlet is disposed at or near one side of the central frame body portion, and wherein at least one of the one or more bias flow vents is disposed at or near the other side of the central frame body portion between the interface body and the frame.

The nasal interface of any one of clauses 71, 57-70, wherein the interface body comprises a single outlet for delivering gas to the first and second nostrils of the patient.

The nasal interface of any one of clauses 72, 57-71, wherein the interface body comprises a first nasal delivery element having a first outlet and a second nasal delivery element having a second outlet, wherein the first nasal delivery element and the second nasal delivery element are each configured to seal with a respective nostril of the patient.

Clause 73, the nasal interface of any of clauses 57-72, wherein the interface body comprises a first interface body side arm and a second interface body side arm, wherein the first interface body side arm and the second interface body side arm each comprise an unsealed lumen to enhance the flexibility of the first interface body side arm and the second interface body side arm.

Clause 74, the nasal interface of clause 73, wherein each interface body side arm comprises a patient proximal wall configured to contact, in use, a patient cheek and a patient distal wall configured to be spaced apart, in use, from the patient cheek, wherein the patient proximal wall is spaced apart from the patient distal wall with an unsealed lumen therebetween.

Clause 75, a nasal interface, comprising:

Clause 76, the nasal interface of clause 75, wherein the nasal interface comprises a gas flow passage in the nasal interface, and wherein at least one of the one or more elongated deflection holes extends from a position proximate to the gas inlet to a position at or proximate to the gas flow passage end.

Clause 77, the nasal interface of clause 76, wherein one end of at least one of the one or more elongated deflection holes is proximate to the periphery of the outlet of the gas inlet.

The nasal interface of any one of clauses 78, 75-77, wherein the nasal interface comprises an interface body and a frame, wherein the interface body comprises a first nasal delivery element and a second nasal delivery element, wherein the frame comprises a bias flow vent.

Clause 79, the nasal interface of clause 78, wherein the frame comprises a recess, and wherein the bias flow vent is located in the recess.

Clause 80, the nasal interface of clause 79, wherein the recess has an irregular shape.

Clause 81, the nasal interface of clause 80, wherein the recess has an irregular polygonal shape.

The nasal interface of any one of clauses 82, 75-81, wherein the at least one flow deflecting aperture has one dimension that is larger than another dimension.

The nasal interface of any one of clauses 83, 75-82, wherein the bias flow discharge port comprises a plurality of elongated bias flow holes.

Clause 84, the nasal interface of clause 83, wherein the plurality of elongated offset holes are arranged substantially parallel to each other.

The nasal interface of any one of clauses 85, 75-84, wherein the bias flow vent comprises a diffuser to diffuse gas flowing through the one or more elongated bias flow holes.

The nasal interface of any one of clauses 86, 75-85, wherein the gas inlet and the first and second nasal delivery elements are in fluid communication with the gas flow path of the interface body to deliver breathing gas from the gas inlet through the first and second nasal delivery elements.

The nasal interface of any one of clauses 87, 75-86, wherein the one or more elongated deflection holes are elongated in a direction extending across the nasal interface.

Clause 88, a nasal interface, comprising:

A gas inlet for delivering breathing gas into the nasal interface,

A bias flow vent for airflow out of the nasal interface,

Clause 89, the nasal interface of clause 88, wherein the gas inlet is positioned closer to the first nasal delivery element than the second nasal delivery element.

Clause 90, the nasal interface of clauses 88 or 89, wherein the bias flow discharge is positioned closer to the second nasal delivery element than the first nasal delivery element.

Clause 91, the nasal interface of any of clauses 87-90, wherein the outlet has a non-circular cross-sectional shape.

The nasal interface of any one of clauses 92, 87-91, wherein the bias flow vent comprises one or more elongated bias flow holes.

Clause 93, a nasal interface, comprising:

Clause 94, the nasal interface of clause 93, wherein the projection comprises a ring surrounding the base of the first nasal delivery element.

Clause 95, the nasal interface of clauses 93 or 94, wherein the protrusion defines a protrusion gas flow passage, and wherein the protrusion gas flow passage has a larger cross-sectional area at an end region closer to the gas inlet than at a region closer to the first nasal delivery element.

The nasal interface of any one of clauses 96, 93-95, wherein the protrusion forms a funnel to direct the gas flow from the gas inlet into the first nasal delivery element.

The nasal interface of any one of clauses 97, 93-96, wherein the protrusion is integrally formed with the interface body.

The nasal interface of any one of clauses 98, 93-97, wherein the protrusion comprises a plurality of protrusions.

Clause 99, a nasal interface, comprising:

A gas inlet for delivering breathing gas to the first gas flow passage,

Clause 100, the nasal interface of clause 99, wherein the gas inlet is configured to direct the flow of breathing gas from the gas inlet to the outlet of the first nasal delivery element, optionally at least the outlet of the gas inlet is arranged to direct the flow of breathing gas to the outlet of the first nasal delivery element.

Clause 101, the nasal interface of clauses 99 or 100, wherein the nasal interface comprises an interface body and a frame, wherein the interface body comprises a first nasal delivery element and a second nasal delivery element, wherein the wall is provided by the frame, or by the interface body, or by the frame and the interface body.

Clause 102, the nasal interface of clauses 99 or 100, wherein the nasal interface comprises an insert for positioning in or in the interface body, wherein the insert comprises a wall.

Clause 103, the nasal interface of clause 102, wherein the insert comprises two wings protruding laterally outward from the wall in opposite directions from each other.

Clause 104, the nasal interface of clause 103, wherein the wings protrude laterally outward from the rear of the wall in opposite directions from each other.

Clause 105, the nasal interface of clause 104, wherein the wing is configured to contact an interface body inner surface proximate to the base of the first and second nasal delivery elements.

Clause 106, the nasal interface of any of clauses 103-105, wherein each wing comprises a ring member having a dimension at least equal to or greater than the base of the first and second nasal delivery elements.

Clause 107, the nasal interface of any of clauses 103-106, wherein the wing is configured to form a seal against an inner surface of the interface body.

The nasal interface of any one of clauses 108, 102-107, wherein the insert, the interface body, and/or the frame of the nasal interface comprise one or more engagement features for engaging the insert in the nasal interface.

The nasal interface of any one of clauses 109, 99-108, wherein the nasal interface is configured such that, in use, the bias flow vent creates a pressure in the second gas flow path to minimize a pressure differential between the pressures created in the first and second gas flow paths.

The nasal interface of any one of clauses 110, 99-109, wherein the wall is configured to cause unidirectional airflow during use, optionally during a phase of a patient's respiratory cycle.

Clause 111, the nasal interface of any of clauses 99-110, wherein the wall comprises a shape corresponding to the cross-sectional shape of the first gas flow passage, the second gas flow passage, or both the first gas flow passage and the second gas flow passage.

The nasal interface of any one of clauses 112, 99-111, wherein the wall has the same rigidity as the interface body or has a different rigidity than the interface body.

Clause 113, the nasal interface of clause 112, wherein the wall comprises the same material as the interface body or comprises a different material than the interface body.

The nasal interface of any one of clauses 114, 99-111, wherein the nasal interface comprises an interface body and/or a frame, and wherein the wall has the same rigidity as the frame or has a different rigidity than the frame.

Clause 115, the nasal interface of any of clauses 99-114, wherein the bias flow vent comprises one or more elongated bias flow holes.

Clause 116, a respiratory therapy system, comprising:

A breathing tube for receiving a pressure-controlled breathing gas; and

The nasal interface of any one of clauses 1-115, in fluid communication with a breathing tube to deliver breathing gas to a patient.

Clause 117, the respiratory therapy system of clause 116, wherein the respiratory therapy system comprises a respiratory conduit to receive the pressure controlled respiratory gas from the respiratory tube, wherein the respiratory conduit is in fluid communication with the respiratory tube and the gas inlet of the nasal interface.

Clause 118, the respiratory therapy system of clauses 116 or 117, wherein the respiratory therapy system further comprises a humidifier configured to humidify the pressure-controlled respiratory gas prior to delivery to the nasal interface.

Clause 119, the respiratory therapy system of clause 118, wherein the breathing tube is a heated breathing tube and is configured to receive the pressure controlled breathing gas from the humidifier.

The respiratory therapy system according to any one of clauses 120, 116 to 119, wherein the temperature of the air flow exiting the nasal interface for delivery to the nasal airway of the patient is between about 31 ℃ and about 41 ℃, optionally greater than 31 ℃ and up to about 41 ℃, optionally between about 36 ℃ and about 39 ℃, optionally about 37 ℃.

Claims

1. A nasal interface, characterized in that, the nasal interface comprises: