CN118543007A

CN118543007A - Patient interface

Info

Publication number: CN118543007A
Application number: CN202410202467.8A
Authority: CN
Inventors: A·范沙尔魁克; S·C·M·桑森; D·R·威廷; S·R·弗雷姆; S·塔特科夫
Original assignee: Fisher and Paykel Healthcare Ltd
Current assignee: Fisher and Paykel Healthcare Ltd
Priority date: 2023-02-24
Filing date: 2024-02-23
Publication date: 2024-08-27
Also published as: WO2024176179A1

Abstract

The present application relates to a nasal interface (100) for delivering a flow of gas to a patient. The nasal interface (100) has a first prong (111), a second prong (112), and a gas manifold (120). The nasal interface (100) is configured to induce asymmetric flow at the nostrils of the patient. At least one of the first prong (111), the second prong (112), or the gas manifold (120) includes a flow resistance positioned to increase a flow of gas traveling therethrough, thereby reaching the at least one prong (111, 112).

Description

Patient interface

The present application claims priority from U.S. provisional application No.63/486,795, filed 24 months 2 of 2023, entitled "patient interface," the entire contents of which are incorporated herein by reference.

Technical Field

The present disclosure relates generally to a patient interface for delivering respiratory gases to an airway 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 a high flow of gas to a patient. Nasal delivery prongs or elements are inserted into the patient's nose to deliver the desired treatment. To deliver the treatment, the nasal delivery prongs may or may not need to be sealed or semi-sealed at the nose. Nasal high flow is typically a non-sealing treatment that delivers a relatively high volume of flow to the patient through the nasal interface, which may be sufficient to meet or exceed the patient's inspiratory flow rate.

Disclosure of Invention

Disclosed herein is a nasal interface having features that allow the nasal interface to provide asymmetric flow to a patient. The nasal interface may be configured to deliver nasal high flow. The asymmetric flow may provide increased dead zone clearance for the patient in the upper airway. One or more features of the nasal interfaces disclosed herein that allow the nasal interface to achieve asymmetric flow at the patient's nostrils may reduce the (total) resistance to flow through the nasal interface, which may use lower back pressure and/or lower motor speed of the flow generating device to achieve a desired flow rate.

According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, there is provided a nasal interface comprising: a first fork having a first base and a first end; a second fork having a second base and a second end; a gas manifold comprising a manifold chamber and a gas inlet; and at least one element positioned within the first prong, the second prong, or the manifold chamber, wherein the at least one element is configured to increase resistance to gas flow traveling through at least one of the first prong, the second prong, or the manifold chamber, and wherein the gas inlet is in fluid communication with the gas delivery conduit, or is configured to be in fluid communication with the gas delivery conduit.

According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, there is provided a nasal interface comprising: a first fork having a first base and a first end; a second fork having a second base and a second end; a gas manifold comprising a manifold chamber and a gas inlet; and a second prong element positioned at the second prong, wherein the second prong element is configured to increase a flow resistance of a gas flow traveling through the second prong, and wherein the gas inlet is in fluid communication with the gas delivery conduit or is configured to be in fluid communication with the gas delivery conduit.

According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, there is provided a nasal interface comprising: a first fork having a first base and a first end; a second fork having a second base and a second end; a gas manifold comprising a manifold chamber and a gas inlet; and a manifold element positioned within the manifold chamber, wherein the manifold element is configured to increase resistance to gas flow traveling through the manifold chamber and to at least one of the first prong or the second prong, and wherein the gas inlet is in fluid communication with the gas delivery conduit or is configured to be in fluid communication with the gas delivery conduit.

In some configurations, the increase in resistance to gas flow is configured to induce asymmetric gas flow at the first and second prongs.

In some configurations, the first prong, the second prong, the manifold chamber, and the gas inlet are in fluid communication with one another.

In some constructions, the at least one element is a second fork element positioned within the second fork.

In some configurations, the second fork element is configured to increase resistance to gas flow traveling through the second fork.

In some constructions, the second binary element is positioned at the second base.

In some constructions, the second base of the second prong includes an inlet to a flow passage formed by a wall of the second prong.

In some configurations, the nasal interface comprises a manifold element, wherein the manifold element is positioned within a manifold chamber of the gas manifold.

In some constructions, the manifold element is configured to increase the flow resistance of the gas flow traveling through the manifold chamber.

In some configurations, the gas flow is substantially in a direction from the gas manifold inlet, through the gas manifold chamber, and into the flow channels of the first prong and/or the second prong.

In some constructions, the manifold element is positioned substantially at the center of the manifold chamber.

In some constructions, the nasal interface includes a first prong element, wherein the first prong element is positioned within the first prong.

In some configurations, the first fork element is configured to increase the flow resistance of the gas flow traveling through the first fork.

In some constructions, the first fork element is positioned at the base of the first fork.

In some configurations, the first prong element provides a different resistance to gas flow than the second prong element.

In some constructions, the gas delivery conduit is located between the patient conduit and the gas inlet.

In some constructions, the gas manifold is integrally formed with, or coupled to, the gas delivery conduit.

In some configurations, the gas manifold includes a manifold width, and wherein the manifold width is as large as or greater than an inner diameter of at least one of the first prong or the second prong.

In some constructions, the nasal interface includes a cannula body including the first prong and the second prong, and wherein an outer surface of the cannula body between the first prong and the second prong includes a recess for receiving a portion of the patient's nose and reducing pressure on an underside of the received portion.

In some configurations, at least one of the first prong or the second prong is sized to maintain a sufficient gap between an outer surface of the at least one prong and the patient's skin to avoid sealing a gas path between the nasal interface and the patient.

In some constructions, at least the first prong or the second prong is made of an elastomeric material that enables the first prong to deform and set its shape in use in response to temperature and contact with the patient's nostrils.

In some constructions, at least one of the first prong or the second prong is not made of silicone.

In some constructions, at least one of the first prong or the second prong is made of a thermoplastic elastomer.

In some configurations, the nasal interface is configured to induce asymmetric gas flow at the nostrils of the patient.

In some constructions, the gas manifold includes a flow channel having a gas flow direction substantially perpendicular to a gas flow path through the first prong and the second prong.

In some constructions, the manifold element includes a manifold aperture for the passage of a gas flow therethrough, wherein the aperture has a smaller cross-sectional opening than the manifold chamber for the gas flow.

In some constructions, the second prong includes a second aperture for the passage of the gas flow, wherein the second aperture has a smaller cross-sectional opening than the second prong for the gas flow.

In some constructions, the manifold hole and/or the second hole are formed in a plate or wall.

In some constructions, the plate or wall has an inlet surface and an outlet surface, with the manifold hole and/or the second hole being formed between the inlet surface and the outlet surface.

In some configurations, the gas flow is in a direction from the inlet surface to the outlet surface through the manifold hole and/or the second hole.

In some configurations, the transition between the outlet surface and the manifold hole and/or the second hole is tapered.

In some constructions, the transition between the inlet surface and the manifold hole and/or the second hole is substantially right angle.

In some configurations, the transition between the inlet surface and the manifold hole and/or the second hole is tapered, wherein the taper angle of the outlet surface is greater than the taper angle of the inlet surface.

In some constructions, the transition between the inlet surface and the manifold hole and/or the second hole is substantially sharp.

In some constructions, the at least one manifold hole and/or the second hole is a gap, cut, or slit extending longitudinally vertically through the plate or wall.

In some constructions, the at least one manifold hole and/or the second hole is a gap, cut, or slit extending longitudinally horizontally through the plate or wall.

In some constructions, at least one of the manifold holes and/or the second holes is a generally circular perforation.

In some constructions, at least one of the manifold holes and/or the second holes includes a perforation pattern.

In some constructions, the plate or wall of at least one manifold hole and/or the second hole includes a porous medium.

In some constructions, any one or more of the second fork element and/or the manifold element and/or the first fork element comprises a valve.

In some configurations, the valve is configured to open only at a threshold pressure or a threshold flow rate.

In some constructions, the valve is configured to provide a defined pressure drop in the flow path.

In some constructions, the valve is a duckbill valve.

In some constructions, any one or more of the second prong element and/or the manifold element and/or the first prong element includes a nozzle.

In some configurations, the nozzle is configured to provide a defined pressure drop in the flow path.

In some constructions, the manifold element is configured to be adjusted via manual actuation to increase or decrease the degree of restriction by the manifold element.

In some constructions, the manifold element is configured to be slidably movable in an upstream-downstream direction.

In some constructions, wherein the manifold element includes a rotatable member having a helical thread.

In some constructions, the manifold element further includes an outer portion that is located outside of the gas manifold of the nasal interface.

In some constructions, the manifold element is configured to rotatably move such that when the outer portion rotates, the manifold element translates vertically into or out of the manifold chamber flow path, thereby increasing or decreasing, respectively, the degree of flow restriction in the flow path.

In some constructions, the gas manifold includes an opening at a wall generally opposite the gas inlet of the manifold and/or generally opposite the second base of the second prong.

In some constructions, the opening includes one or more holes.

In some configurations, the number and diameter of the holes are configured to provide a defined pressure drop.

In some constructions, the openings in the wall of the manifold are pneumatically connected to members configured to provide a defined pressure drop.

In some constructions, the member is at least one of a porous medium, a nozzle, a pressure relief valve, or a bubble CPAP bubbling chamber.

In some configurations, the axis of the gas inlet is coaxial with respect to the axis of at least one of the first prong or the second prong.

In some configurations, the angle of the axis of the gas inlet is perpendicular relative to the axis of at least one of the first prong or the second prong.

In some configurations, the nasal interface includes an auxiliary gas inlet to induce or promote asymmetric gas flow at the first prong and the second prong.

In some configurations, the auxiliary gas inlet terminates in either the first prong or the second prong.

In some configurations, the secondary gas conduit includes an inlet and terminates at the inlet in the first prong or the second prong.

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

In some configurations, at least one of the gas inlet or the gas delivery conduit comprises a lumen having a first internal cross-sectional area, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit comprises a lumen having a second internal cross-sectional area.

In some constructions, one or both of the first and second internal cross-sectional areas are substantially circular.

In some constructions, the first internal cross-sectional area and the second internal cross-sectional area are different.

In some constructions, the second internal cross-sectional area is less than the internal cross-sectional area of the first prong or the second prong.

In some constructions, the gas delivery conduit and the auxiliary gas delivery conduit are disposed on the same side of the manifold chamber.

In some constructions, the auxiliary gas delivery conduit is positioned in the gas delivery conduit.

In some configurations, at least one of the gas inlet or the gas delivery conduit comprises a first length and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit comprises a second length.

In some configurations, the first length and the second length are unequal to induce or promote asymmetric gas flow at the first prong and the second prong.

In some configurations, the first length is longer than the second length to induce or promote asymmetric gas flow at the first and second prongs.

In some configurations, the first length is shorter than the second length to induce or promote asymmetric gas flow at the first and second prongs.

In some configurations, the gas delivery conduit is in communication with a first gas stream and the auxiliary gas delivery conduit is in communication with a second gas stream.

In some constructions, the first gas stream has a different flow rate than the second gas stream.

In some configurations, the resultant flow direction between the gas manifold and the first gas stream is a different flow direction than the resultant flow direction between the gas manifold and the second gas stream.

In some configurations, one of the first gas stream or the second gas stream is an inhalation stream.

In some configurations, the gas pressure of the first gas stream is different than the gas pressure of the second gas stream.

In some constructions, the negative gas pressure relative to the environment is formed by the first gas flow or the second gas flow.

According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, there is provided a nasal interface comprising: a first fork having a first base and a first end; a second fork having a second base and a second end; and a gas manifold comprising: a manifold chamber; a first gas inlet; and a second gas inlet, wherein the first gas inlet and the second gas inlet are disposed on opposite ends of the manifold chamber and are in fluid communication with the first gas delivery conduit and the second gas delivery conduit, respectively.

According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, there is provided a nasal interface comprising: a first fork having a first base and a first end; a second fork having a second base and a second end; and a gas manifold comprising: a manifold chamber; a first gas inlet; a second gas inlet, wherein the first gas inlet and the second gas inlet are in fluid communication with the first gas delivery conduit and the second gas delivery conduit, respectively, wherein the nasal interface is configured to induce asymmetric gas flow at the first prong and the second prong.

In some constructions, the first gas inlet and the second gas inlet are disposed on opposite sides of the manifold chamber.

In some configurations, the first gas inlet is closer to the first prong than the second gas inlet, and wherein the second gas inlet is closer to the second prong than the first gas inlet.

In some constructions, at least one of the first gas inlet and the first gas delivery conduit is formed as a unitary structure, or the second gas inlet and the second gas delivery conduit are formed as a unitary structure.

In some configurations, a first gas delivery conduit is in communication with the first gas stream and a second gas delivery conduit is in communication with the second gas stream.

In some configurations, the first prong, the second prong, the manifold chamber, the first gas inlet, and the second gas inlet are in fluid communication with one another.

In some configurations, the nasal interface includes a flow altering feature configured to cause asymmetric gas flow at the first prong and the second prong.

In some configurations, wherein the first inlet and/or the first gas delivery conduit comprises a lumen having a first internal cross-sectional area and the second inlet and/or the second gas delivery conduit comprises a lumen having a second internal cross-sectional area to induce asymmetric gas flow at the first prong and the second prong.

In some constructions, one or both of the first interior cross-sectional area and the second interior cross-sectional area is substantially non-circular.

In some configurations, the first internal cross-sectional area and the second internal cross-sectional area are unequal to induce asymmetric gas flow at the first prong and the second prong.

In some configurations, the first internal cross-sectional area is greater than the second internal cross-sectional area to induce asymmetric gas flow at the first prong and the second prong.

In some configurations, the first internal cross-sectional area is less than the second internal cross-sectional area to induce asymmetric gas flow at the first prong and the second prong.

In some configurations, the first inlet and/or the first gas delivery conduit comprises a first length and the second inlet and/or the second gas delivery conduit comprises a second length to induce asymmetric gas flow at the first prong and the second prong.

In some configurations, the first length and the second length are unequal to cause asymmetric gas flow at the first prong and the second prong.

In some configurations, the first length is longer than the second length to induce asymmetric gas flow at the first and second prongs.

In some configurations, the first length is shorter than the second length to induce asymmetric gas flow at the first and second prongs.

In some constructions, the first inlet and/or the inner surface of the first gas delivery conduit includes a first pattern of relief features.

In some constructions, the second inlet and/or the inner surface of the second gas delivery conduit includes a second pattern of relief features.

In some constructions, the first relief feature pattern is substantially coarser (substianly) than the second relief feature pattern to induce asymmetric gas flow at the first and second prongs.

In some configurations, the first relief feature pattern is substantially smoother (subtotally) than the second relief feature pattern to induce asymmetric gas flow at the first and second prongs.

In some constructions, the relief feature pattern includes one or more of the following: pits, projections, ribs, and/or fins.

In some configurations, the axis of one or both of the first gas inlet and the second gas inlet is coaxial with respect to the axis of at least one of the first prong or the second prong.

In some configurations, the angle of the axis of the first gas inlet and/or the second gas inlet is perpendicular relative to the axis of at least one of the first prong or the second prong.

In some constructions, the nasal interface includes at least one of: (i) a first fork element positioned within the first fork; (ii) a second fork element positioned within the second fork; (iii) A manifold element positioned in the manifold chamber and between the first base of the first fork and the second base of the second fork; (iv) A first gas inlet element positioned at a first gas inlet to the gas manifold; or (v) a second gas inlet element positioned at a second gas inlet to the gas manifold, wherein the first prong element, the second prong element, the manifold element, the first gas inlet element, and/or the second gas inlet element are each configured to increase the flow resistance of the gas flow into the corresponding element to cause asymmetric gas flow at the first prong and the second prong.

In some configurations, the nasal interface includes the first and second gas inlet elements each configured to increase a flow resistance of a gas flow entering the gas manifold through the first and second gas inlets, respectively.

In some configurations, the nasal interface includes the first prong element and the second prong element, each configured to increase a flow resistance of the gas flow into the first prong and the second prong, respectively.

In some configurations, the nasal interface includes the manifold element and the first gas inlet element, each configured to increase a flow resistance of a gas flow within the manifold chamber and into the gas manifold through the manifold element and the first gas inlet element, respectively.

In some configurations, the nasal interface includes the manifold element and the second gas inlet element, each configured to increase a flow resistance of a gas flow within the manifold chamber and into the gas manifold through the manifold element and the second gas inlet element, respectively.

In some configurations, at least one of the first prong element, the second prong element, the manifold element, the first gas inlet element, or the second gas inlet element includes an aperture for a passage for reducing gas flow.

In some configurations, wherein the aperture has a smaller cross-sectional opening than at least one of the flow channel for the first prong, the second prong, or the manifold chamber, or the first lumen or the second lumen for the gas flow.

In some constructions, the aperture is formed in a plate or wall.

In some constructions, the plate or wall has an inlet surface and an outlet surface with an aperture formed therebetween.

In some constructions, the gas flow is in a direction from the inlet surface through the aperture to the outlet surface.

In some constructions, the transition between the outlet surface and the aperture is tapered.

In some constructions, the transition between the inlet surface and the aperture is substantially right-angled.

In some configurations, the transition between the inlet surface and the aperture is tapered, wherein the taper angle of the outlet surface is greater than the taper angle of the inlet surface.

In some constructions, the transition between the inlet surface and the aperture is a substantially sharp corner.

In some constructions, the at least one aperture is a gap, cut-out, or slit extending longitudinally vertically through the plate or wall.

In some constructions, the at least one aperture is a gap, cut-out, or slit extending longitudinally horizontally through the plate or wall.

In some constructions, the at least one aperture is a substantially circular perforation.

In some constructions, the at least one aperture includes a perforation pattern.

In some constructions, the plate or wall of the at least one aperture comprises a porous medium.

In some configurations, at least one of the first prong element, the second prong element, the manifold element, the first gas element, or the second gas element includes a valve.

In some constructions, the valve is configured to open only at a threshold pressure or a threshold flow rate.

In some constructions, the valve is a duckbill valve.

In some configurations, at least one of the first prong element, the second prong element, the manifold element, the first gas element, or the second gas element includes a nozzle.

In some configurations, at least one of the first fork element, the second fork element, the manifold element, the first gas element, or the second gas element is configured to be adjusted via manual actuation to increase or decrease the degree of restriction by the element.

In some constructions, the element is configured to be slidably movable in an upstream-downstream direction.

In some constructions, the element includes a rotatable member having a helical thread.

In some constructions, the element further includes an outer portion that is located outside of the nasal interface.

In some constructions, the element is configured to rotatably move such that when the outer portion rotates, the element translates vertically into or out of the flow path, thereby increasing or decreasing, respectively, the degree of flow restriction in the flow path.

According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, there is provided a nasal interface comprising: a first fork and a second fork; a gas manifold comprising a manifold chamber and a gas inlet in fluid communication with, or configured to be in fluid communication with, a gas delivery conduit; and at least one flow directing element, wherein the at least one flow directing element is configured to direct a flow of gas from the gas inlet to one of the first prong or the second prong to create an asymmetric flow of gas.

In some constructions, the at least one flow directing element is a gas inlet.

According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, there is provided a nasal interface comprising: a first fork and a second fork; a gas manifold comprising a manifold chamber and a gas inlet in fluid communication with, or configured to be in fluid communication with, a gas delivery conduit; and at least one flow directing element formed as part of at least one of the manifold chamber, the gas inlet, or the gas delivery conduit, wherein the at least one flow directing element is configured to direct the flow of gas to one of the first prong or the second prong to create an asymmetric flow of gas.

In some configurations, the first prong, the second prong, the manifold chamber, and the first gas inlet are in fluid communication with one another.

In some configurations, the flow directing element is configured to provide a greater dynamic pressure at the first prong in use and a lesser dynamic pressure at the second prong in use to create an asymmetric gas flow.

In some configurations, the first prong and the second prong are in fluid communication with the manifold chamber.

In some configurations, the gas inlet is positioned in the manifold chamber opposite at least one of the first prong or the second prong.

In some configurations, the at least one flow directing element is positioned within the gas manifold chamber.

In some configurations, the at least one flow directing element is positioned within the gas delivery conduit.

In some configurations, the at least one flow directing element is positioned within the gas delivery conduit where the gas delivery conduit meets the gas inlet.

In some configurations, the at least one flow directing element comprises at least one angled protrusion, wherein the protrusion is configured to direct the flow of gas from the gas inlet toward one of the first prong or the second prong.

In some configurations, the at least one flow directing element further includes an angled second protrusion positioned opposite the first protrusion in the flow path and similarly configured to direct the flow of gas from the gas inlet toward one of the first prong or the second prong.

In some configurations, the nasal interface includes a second flow directing element positioned in the gas manifold at an inlet to one of the first prong or the second prong.

In some configurations, the second flow directing element is configured to direct the flow of gas from the gas inlet toward one of the first prong or the second prong.

In some configurations, the second flow directing element is configured to direct the flow of exhaled gas from either the first prong or the second prong to the opposite prong.

In some configurations, the second flow directing element comprises at least one angled protrusion, wherein the protrusion is configured to direct a flow of gas from the gas inlet toward one of the first prong or the second prong, and is configured to direct a flow of exhaled gas from the first prong or the second prong to the opposite prong.

In some configurations, the gas inlet is positioned in the manifold chamber at a substantially central location between the first prong and the second prong.

In some configurations, the at least one flow directing element is positioned within the gas manifold chamber and adjacent to the first prong.

In some configurations, the at least one flow directing element is configured to direct a flow of gas from the gas delivery conduit toward the inlet of the first prong.

In some configurations, the second flow directing element is configured to direct a flow of gas from an inlet of the first prong into a flow passage of the first prong.

In some configurations, the at least one flow directing element is positioned within the gas manifold chamber and adjacent to the second prong.

In some configurations, the at least one flow directing element is configured to direct a flow of gas from the gas delivery conduit toward an inlet of the second fork.

In some configurations, the second flow directing element is configured to direct a flow of gas from an inlet of the second prong into the flow passage of the second prong.

In some constructions, the nasal interface includes at least one of: (i) a first fork element positioned within the first fork; (ii) a second fork element positioned within the second fork; (iii) A manifold element positioned in the manifold chamber and between the first base of the first fork and the second base of the second fork; wherein the first fork element, the second fork element and/or the manifold element are each configured to increase the flow resistance of the gas flow into the corresponding element.

In some configurations, the nasal interface includes a first prong element and a second prong element, each configured to increase the flow resistance of the gas flow into the first prong and the second prong, respectively.

In some configurations, the nasal interface includes a manifold element and a second prong element, each configured to increase flow resistance of the gas flow through the second prong element and the manifold element into the second prong and within the manifold chamber, respectively.

In some configurations, at least one of the first prong element, the second prong element, and/or the manifold element includes an aperture for reducing the gas flow passage.

In some constructions, the aperture has a smaller cross-sectional opening than a cross-section of the flow channel for at least one of the first prong, the second prong, or the manifold chamber.

In some constructions, the first prong has a first prong length and the second prong has a second prong length, and wherein the first prong length is different from the second prong length.

In some configurations, the first prong length is longer than the second prong length to induce or promote asymmetric gas flow at the first prong and the second prong.

In some configurations, the first prong length is shorter than the second prong length to induce or promote asymmetric gas flow at the first prong and the second prong.

In some constructions, the first prong has a first prong cross-sectional width and the second prong has a second prong cross-sectional width, and wherein the first prong cross-sectional width is different from the second prong cross-sectional width.

In some configurations, the first prong cross-sectional width is greater than the second prong cross-sectional width to induce or promote asymmetric gas flow at the first prong and the second prong.

In some configurations, the first prong cross-sectional width is less than the second prong cross-sectional width to induce or promote asymmetric gas flow at the first prong and the second prong.

In some configurations, the first prong has a first end and the second prong has a second end, and wherein the geometry of the first end and the geometry of the second end are different to cause or promote asymmetric gas flow at the first prong and the second prong.

In some configurations, at least one of the first end or the second end narrows or tapers to form a nozzle shape.

In some constructions, at least one of the first end or the second end widens or tapers to form a diffuser shape.

In some constructions, the first prong has a first inner surface and the second prong has a second inner surface, wherein at least one of the first inner surface or the second inner surface has a surface feature configured to affect an internal flow resistance of the at least one first prong or the second prong.

In some constructions, the surface features are ridges formed in a concentric pattern as rings, spirals, or bands around the first inner surface or the second inner surface.

In some constructions, the surface features are fins formed as lines, strips, or bars in a substantially axial direction pattern along the first or second inner surfaces.

In some configurations, when surface features are present on the first and second inner surfaces, the surface features are different to cause asymmetric gas flow at the first and second prongs.

In some configurations, at least one of the first prong and the second prong is a non-circular cross-sectional shape configured to affect an internal flow resistance of the at least one first prong or the second prong.

In some constructions, the non-circular cross-sectional shape is reduced by the size of the circular cross-sectional shape removed therefrom.

In some constructions, the non-circular cross-sectional shape is substantially U-shaped.

In some constructions, the non-circular cross-sectional shape is substantially polygonal.

In some configurations, when a non-circular cross-sectional shape is present on each of the first prong and the second prong, the non-circular cross-sectional shape is different to induce or promote asymmetric gas flow at the first prong and the second prong.

In some configurations, at least one of the first prong and the second prong includes a base restriction at a base of the prong, the base restriction configured to affect an internal flow resistance of the at least one first prong or the second prong.

In some constructions, the base restriction is a nozzle or diffuser formed at the base of the fork.

In some configurations, when there is a base restriction on the first prong and the second prong, the base restriction is different to cause or promote asymmetric gas flow at the first prong and the second prong.

In some configurations, at least one of the first prong and the second prong includes a valve located within the prong, the valve configured to affect an internal flow resistance of the at least one first prong or the second prong.

In some constructions, the valve is configured to restrict or prevent the flow of gas therethrough until the flow of gas exceeds a defined pressure.

In some constructions, the valve is a duckbill valve.

In some constructions, the valve is a one-way valve.

In some configurations, when a valve is present in each of the first prong and the second prong, the valve has different characteristics to cause asymmetric gas flow at the first prong and the second prong.

In some configurations, the nasal interface further comprises a third prong, wherein the first prong, the second prong, and the third prong are spaced apart to be engageable into the nostril of the patient as adjacent pairs, wherein at least one of the first prong, the second prong, or the third prong has different flow characteristics than the other prongs to induce or promote asymmetric gas flow at each prong.

In some constructions, the nasal interface further comprises a closure for releasably preventing gas flow through the first prong, the second prong, or the third prong.

According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, there is provided a nasal interface comprising: a first fork having a first base and a first end; a second fork having a second base and a second end; a gas manifold; a first gas inlet; and an auxiliary gas inlet; wherein the first gas inlet and the second gas inlet are in fluid communication with the first gas delivery conduit and the second gas delivery conduit, respectively; wherein the nasal interface is configured to induce asymmetric gas flow at the first prong and the second prong.

In some constructions, the first gas inlet terminates in a gas manifold.

In some configurations, at least one of the first gas inlet or the gas delivery conduit includes a lumen having a first internal cross-sectional area, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit includes a lumen having a second internal cross-sectional area.

In some constructions, one or both of the first interior cross-sectional area and the second interior cross-sectional area is substantially circular.

In some constructions, the gas delivery conduit and the auxiliary gas delivery conduit are disposed on the same side of the gas manifold.

In some constructions, the secondary gas delivery conduit is located in the gas delivery conduit.

In some configurations, at least one of the first gas inlet or the gas delivery conduit comprises a first length and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit comprises a second length.

According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a patient interface is provided that includes a nasal interface as described herein.

In some constructions, the patient interface further includes a headgear to retain the nasal interface on the patient's face.

In some configurations, the patient interface further comprises a gas delivery conduit in fluid communication with the gas inlet.

In some constructions, wherein the gas delivery conduit is a gas permeable tube.

In some configurations, wherein the gas manifold is integrally formed with, or coupled to, the gas delivery conduit.

In some configurations, the gas delivery conduit couples the gas inlet to a patient conduit that provides gas from the flow generator.

In some constructions, the patient interface further comprises a gas delivery conduit retaining clip.

According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, there is provided a respiratory therapy system comprising: a respiratory therapy apparatus, comprising: a controller; a blood oxygen saturation sensor; an ambient air inlet; an oxygen inlet; a valve in fluid communication with the oxygen inlet to control the flow of oxygen through the oxygen inlet; and a gas outlet; wherein the controller is configured to control the valve based on at least one measurement of oxygen saturation from the blood oxygen saturation sensor; and a patient interface as described 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 "plurality of" following a noun refers to the plural and/or singular form of the noun.

As used herein, the term "and/or" means "and" or both, as the context allows.

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

References to numerical ranges disclosed herein (e.g., 1 to 10) are also intended to include references to all rational numbers within the range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10), as well as references to any rational number range within the range (e.g., 2 to 8, 1.5 to 5.5, and 3.1 to 4.7), and therefore all subranges of all ranges explicitly disclosed herein are also explicitly disclosed. 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 said parts, elements or features.

Where specific integers are mentioned herein having known equivalents in the art to which this disclosure relates, such known equivalents are deemed to be incorporated herein 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 modifications thereof will be apparent to those skilled in the art from the detailed description herein with reference to the following drawings, in which:

fig. 1A is a front left perspective view of a patient interface of an exemplary configuration of the present disclosure, including a nasal interface.

Fig. 1B is a front right perspective view of the patient interface.

Fig. 1C is a front left exploded perspective view of a patient interface.

Fig. 1D is a front view of the nasal interface.

Fig. 2 is a front view of a nasal interface according to the present disclosure, schematically illustrating elements.

Fig. 3A is a schematic perspective view of elements of the nasal interface of fig. 2.

Fig. 3B is a schematic front view of the element of fig. 3A in a possible configuration.

Fig. 3C is a schematic front view of the element of fig. 3A in a possible configuration.

Fig. 4 is a front view of a modification of a nasal interface according to the present disclosure.

Fig. 5 is a front view of a modification of the nasal interface according to the present disclosure.

Fig. 6 is a front view of a modification of the nasal interface according to the present disclosure.

Fig. 7 is a front view of a modification of the nasal interface of fig. 6.

Fig. 8 is a front view of a modification of the nasal interface of fig. 6.

Fig. 9 is a front view of a modification of a nasal interface according to the present disclosure.

Fig. 10 is a front view of a modification of the nasal interface of fig. 9.

Fig. 11 is a front view of the nasal interface of fig. 9, schematically illustrating elements.

Fig. 12 is a front view of a modification of the nasal interface according to the present disclosure.

Fig. 13 is a front view of a modification of the nasal interface according to the present disclosure.

Fig. 14 is a front view of a modification of a nasal interface according to the present disclosure.

Fig. 15 is a front view of a modification of the nasal interface of fig. 14.

Fig. 16 is a front view of a modification of the fork of the nasal interface according to fig. 1D.

Fig. 17 is a front view of a modification of the fork of the nasal interface according to fig. 1D.

Fig. 18 is a front view of a modification of the fork of the nasal interface according to fig. 1D.

Fig. 19 is a front view of a modification of the fork of the nasal interface according to fig. 1D.

Fig. 20 is a front view of a modification of the fork of the nasal interface according to fig. 1D.

Fig. 21 is a front view of a modification of the fork of the nasal interface according to fig. 1D.

Fig. 22 is a front view of a modification of the fork of the nasal interface according to fig. 1D.

Fig. 23 is a front view of a modification of the nasal interface according to fig. 1D.

Fig. 24 illustrates a respiratory therapy system incorporating the patient interface and nasal interface of the present disclosure.

Fig. 25 shows a control loop for a respiratory therapy system with closed-loop blood oxygen saturation (SpO 2) control.

Fig. 26 illustrates an alternative respiratory therapy system incorporating the patient interface and nasal interface of the present disclosure.

Fig. 27 illustrates a cross-sectional view of a patient catheter that may be used in the respiratory therapy system of the present disclosure and/or with a nasal interface.

Fig. 28 illustrates a cross-sectional view of an alternative patient catheter that may be used in the respiratory therapy system of the present disclosure and/or with a nasal interface.

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 a flow of gas to a patient. A nasal delivery element (e.g., a nasal prong or pillow) is inserted into the patient's nose to deliver the desired treatment. Nasal delivery prongs may need to be 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 asymmetric gas flow to each naris, for example, causing a pressure differential at the first and second prongs of the nasal interface. Asymmetric flow as described herein refers to different flows within a nasal interface (e.g., nasal prongs) or within a nose (e.g., different flows between nostrils). In this way, a different stream may be delivered by each nasal prong. The asymmetric stream may also comprise a partially unidirectional stream.

Delivery of asymmetric flow may improve dead zone clearance in the upper airway. The described nasal interface is configured to produce such asymmetric flow through the flow restricting element.

The flow resulting from respiratory therapy depends on the flow through the nasal interface, which depends on the pressure at each nasal prong. If the pressure at each nasal prong is different, an asymmetric gas flow will be created.

If flow, leakage, or a combination of flow and leakage through the nasal interface is asymmetric, flow through the nose may become asymmetric during breathing. The partial unidirectional flow may be an asymmetric flow. As air is flushed out of the upper airway, the partial unidirectional flow may provide improved clearance of anatomical dead spaces. Partial unidirectional flow may be more comfortable than full unidirectional flow. Full unidirectional flow in this context includes all flow entering one nostril through the nasal delivery prongs and exiting through the other nostril. The partial unidirectional flow as described herein includes flow that may enter the nose via both nostrils and exit the nose from one nostril, flow that may enter the nose via one nostril and exit the nose via both nostrils, or flow that may enter the nose via different proportions of the two nostrils and/or flow that may exit the nose via both nostrils, and may be flow that may enter the nose via both nostrils and exit the nose from either nostril or one nostril and optionally exit the nose via the mouth. If there is a pressure differential between the first and second prongs, the first prong will receive more gas flow from the gas inlet during inspiration than the second prong. During exhalation, the second nostril associated with the second nasal prong will exhaust more gas flow than the first nostril associated with the first nasal prong. The pressure differential between the first and second nasal prongs may vary depending on whether the patient's respiratory cycle is in the inspiration phase or the expiration phase.

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

Partial unidirectional flow may reduce turbulence in the nasal cavity of the patient, which may improve comfort.

Fig. 1A-1D illustrate an exemplary patient interface 10 that includes a nasal interface 100 having a first nasal prong 111 and a second nasal prong 112. The nasal interface includes a gas manifold 120 that includes a gas inlet 121.

The first nasal prongs 111 and the second nasal prongs 112 are in fluid communication with the gas inlet 121 via the manifold 120. The gas inlet 121 is located at the manifold 120 such that the first nasal prongs 111 are closer to the gas inlet 121 and the second nasal prongs 112 are further from the gas inlet 121. The gas manifold 120 forms a manifold chamber 125 to allow gas to pass therethrough. Thus, in some constructions, the gas inlet 121 is located on one side or otherwise biased to one side of the gas manifold 120.

The first and second prongs 111 and 112 have flow passages to allow a flow of gas therethrough. The flow paths of the first and second prongs 111 and 112 are formed by their respective inner walls. The gas manifold 120 is in fluid communication with a gas delivery conduit 300 connected by a gas inlet 121. The gas manifold 120 can be removably attached to or integrally molded onto the gas delivery conduit 300.

In the illustrated configuration, the flow of gas passes from the gas delivery conduit 300 through the gas inlet 121, through the manifold chamber 125, to the first nasal prongs 111 and the second nasal prongs 112, and through their respective flow passages to the nostrils of the patient. Thus, the direction of gas flow from the gas delivery conduit 300 defines an upstream direction and a downstream direction. However, it is emphasized that the gas flow is not limited to one direction. For example, patient exhalation may provide gas flow in opposite directions, such as through first nasal prongs 111 and second nasal prongs 112 into gas manifold 120. However, the upstream and downstream definitions as defined above are used herein.

In the illustrated construction, the first and second prongs 111, 112 may be formed as part of the interface body 118. The interface body 118 is a facial mount for engaging the patient's face. The first and second prongs 111, 112 are integrally molded or removably attached with the interface body 118.

The interface body 118 component can be connectable to or engageable with the gas manifold component 120a, or can be integrally formed with or permanently engaged with the gas manifold component 120 a. The interface body 118 and the gas manifold portion 120a form a gas manifold 120.

The interface body 118 may be formed of a soft, flexible material, such as silicone, thermoplastic elastomer, or other polymers known in the art. The first and second prongs 111, 112 may be flexible and may be formed of a silicone layer or other suitable material that is thin enough to achieve this characteristic. The interface body 118 and prongs 111, 112 may be formed, for example, from an elastomeric material capable of conforming to the geometry of the patient's nostrils and/or cheek and providing an effective pneumatic seal.

The interface body 118 includes two side arms extending laterally outward from either side.

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

In some constructions, the first and second prongs 111, 112 extend generally upward and rearward from the interface body 118.

In some constructions, the second prong 112 is closer to the gas inlet 121, while the first prong 111 is further from the gas inlet 121.

The gas inlet 121 is an opening, hole or port in the gas manifold 120 for releasable or permanent connection to a conduit such as the gas delivery conduit 300. In some arrangements, the gas inlets 121 may form tubes or channels that extend from or are part of the gas manifold 120. In some arrangements, the gas inlet 121 has fastening or connecting means for securing to the conduit.

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

In the illustrated construction, the first nasal prongs 111 have openings at their top or distal ends 131 for delivering gas from the gas manifold 120. The gas delivered through the first nasal prongs 111 exits the first nasal prongs 111 via the first ends 131. The first nasal prong 111 has a first base 135 at an end of the first nasal prong 111 opposite the first end 131. The first base 135 is another opening and is connected to the gas manifold 120 and allows gas to flow from the manifold chamber 125 to the first nasal prongs 111. The first base 135 may be integrally formed to or removably connected to the interface body 118.

The second nasal prongs 112 have openings at their top or distal ends 132 for delivering gas from the gas manifold 120. The gas delivered through the second nasal prongs 112 exits the first nasal prongs 112 via the second ends 132. The second prong 112 has a second base 136 at an end of the second prong 112 opposite the second end 132. The second base 136 is another opening that connects to the gas manifold 120 and allows gas to flow from the manifold chamber 125 to and through the second nasal prongs 112. The second base 136 may be integrally formed to or removably connected to the interface body 118.

The first and second prongs 111, 112 may have any suitable shape to seal or insert into the nostrils of the patient. For example, in one configuration, the first and second prongs 111, 112 may be substantially tubular and may be sized larger than the nostrils of the patient, but may be soft or flexible to deform and seal with the nostrils upon insertion into the nostrils. In one example, the first nasal prongs 111 and/or the second nasal prongs 112 are curved, and optionally curved, to point towards the back of the patient's head in use. The first nasal prongs 111 and/or the second nasal prongs 112 may also be configured such that their outlets are directed toward the midline plane of the nasal interface 100. When the nasal interface 100 is in use, this midline position may be parallel to the sagittal plane of the patient. In other words, when the nasal interface 100 is in use, the outlet of the first nasal prongs 111 and/or the second nasal prongs 112 may be directed toward the sagittal plane of the patient. In one configuration, the first and second prongs 111, 112 may be soft or flexible to deform and are sized to form a non-sealing arrangement with the nostrils. In one configuration, the first and second prongs 111, 112 may not enter the nostrils, but are located proximally. In some constructions, the prongs 111, 112 are softer or more flexible than the interface body 118.

The nasal interface 100 provides a patient interface for a patient that is adapted to deliver a high flow of gas, a high humidity flow of gas, to the nasal cavity/nostrils of the patient. In some configurations, the nasal interface 100 is adapted to deliver high flows of gas over a wide flow range (e.g., about 8lpm, or higher depending on other therapeutic applications, possibly such as 10-50lpm or higher). In some constructions, the nasal interface 100 is adapted to deliver relatively low pressure gases.

The gas manifold component 120a may be inserted into the interface body 118 to form the gas manifold 120. The interface body 118 may include at least one substantially horizontal side access passage 118a, 118b that opens into the interior of the base or interface body 118 for releasably receiving the outlet of the gas manifold member 120a therethrough.

The gas manifold component 120a is optionally inserted into the interface body 118 from either of two opposite horizontal directions, i.e., from the left or right. In this manner, the orientation of the gas flow manifold member 120a may be reconfigured relative to the interface body 118. In other words, depending on the most convenient circumstances, for example, depending on which side of the user the gas source or respirator is located, the user may choose to have the gas inlet 121 of the manifold component 120a (and the conduit 300 extending therefrom) extend from either the left or right side of the interface body 118 of the nasal interface 100.

The interface body 118 may include a pair of opposing side access passages 118a, 118b leading to the interior of the base or interface body 118, each adapted to releasably receive an outlet of a gas manifold member 120a therethrough.

The interface body 118 is shaped to generally follow the contours of the patient's face around the upper lip region. The interface body 118 is molded or preformed to conform and/or be pliable in the area of the face where the cannula is to be positioned to accommodate, conform to, and/or correspond to the contours of the user's face. In some constructions, the interface body 118 includes a portion or recess that receives a portion of the patient's nose and reduces pressure on the underside of the received portion.

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.

In the exemplary configuration shown, the main ends 2011 and 2021 of the headgear 200 are adapted to releasably connect the respective structures 101 and 102 located 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 2011, 2021 that can be received and retained within the corresponding configuration 101, 102. The clip members may be coupled to the strap at respective main ends. In addition, the length of the headband 200 is adjustable to help adjust the band according to the wearer's head. The headband 200 may be formed of a soft and stretchable/elastic material, such as an elastic textile material/fabric that is comfortable to the wearer. Or the headband 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 that couple the headgear 200 to extend over the top of the patient's head in use. The overhead strap or overhead member may have the benefit of pulling the strap 200 up and over the patient's ears in use to improve fit and comfort.

Generally, but referring also to fig. 1A-1C, in one exemplary configuration of the adjustable strap 200, the adjustment mechanism is provided in the form of one or more insertable/removable strap segments or strap extensions 2201.

A fixed length belt segment 2201 can be releasably attached to the main belt 210 to extend the length of the main belt. In this configuration, the primary tape 210 includes a pair of intermediate or secondary ends 2031, 2041 that are releasably connected to each other and also releasably connected to the respective ends 2211 and 2221 of the tape segment 2201. When the minor end portions 2031 and 2041 are connected to each other, the major belt 210 has a continuous starting length/dimension for the wearer. To extend the length of the belt 200 beyond this initial length, the primary belt 210 may be broken at the secondary ends 2031/2041 and one or more additional belt segments 2201 connected between the secondary ends.

A plurality of belt segments 2201 having different predetermined lengths may be provided to provide selectable adjustment lengths. For example, one or more band segments 2201 can have a length in a range of about 1cm to about 10cm, or in a 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 intended to be limiting, and that the length of each band segment may be any size, as it depends on the user and/or application.

Furthermore, each end 2211, 2221 of each band segment 2201 may be connected to a respective end 2211, 2221 of another band segment 2201 and/or to a respective minor end 2031, 2041 of the primary band 210, thereby enabling a user to combine one or more band segments 2201 having the same or varying lengths to adjust the overall length of 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 braided headband or portions of headband 210 may be adjusted, particularly for comfort over the user's ears.

It will be appreciated that particular comfort may be achieved by a headgear that is capable of providing proper positioning of the nasal interface 100 at a relatively stable location on the user's face, while also providing a relatively loose fit or a low tension fit around the user's head.

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

A strap connector 2301 is provided at each of the minor ends 2031, 2041 of the main strap 210 and the respective ends 2031, 2041 of the strap section 2201.

Each strap connector 2301 is provided with a strap connection mechanism at one end for coupling to strap material and a coupling mechanism at an opposite end for releasably coupling to a respective end of a similar connector 2301.

In the alternative, strap connector 2301 may be a variety of different forms of adjustable buckles adapted to adjust the length or tension of headgear section 210 holding the patient interface in place around the user's head.

It should also be appreciated that the connector 2301 may be positioned offset from a midpoint of the back of the user's head, or may be offset to one side of the user's head. This may be advantageous in order to avoid collision with a part of the user's head, which may otherwise be uncomfortable for the user at some locations, e.g. while sleeping.

In yet another configuration, the strap segments may have different lengths so as to be asymmetrically disposed or to facilitate operation with offset connector 2301 positions. Furthermore, the length of one of the bands may be adjustable while the length of the other may not be adjustable in both band segments 210. For example, one band segment 210 may be of constant length or permanently connected to connector 2301.

In an exemplary configuration, the strap connection mechanism may include a series of internal teeth within the body of the connector for establishing a friction fit engagement with the respective ends of the strap. The hinged jaw of the body is provided and closes on the teeth to hold the end of the strap securely on the teeth. The releasable connection at the other end includes a pair of male and female members, such as protrusions and holes, respectively, both of which are adapted to connect to corresponding male and female members of a similar connector 230. The lugs on the projections may connect with recesses in the female members to provide a snap-fit engagement between the members. It should be appreciated that in alternative constructions, any other suitable connector construction may be used to releasably connect the minor end portions of the bands to one another and to the ends of the additional band segments.

Cannula connector 2401 is disposed at main ends 2011 and 2021 of main band 210. These connectors 2401 have a strap connection mechanism similar to the strap connectors 2301 of the minor ends 2031 and 2041, but include clip members such as push-fit clips 2411 at the ends of the connectors 2401 opposite the strap ends. The clip 2411 is configured to releasably couple the corresponding formations 101, 102 at the sides of the nasal interface 100. The clip member 2411 may be a bendable component, such as a plastic component, that forms a hinge with respect to the belt. The clip 2411 may be preformed to have a curved shape along its length. In one example, the clip 2411 may be preformed with two or more portions angled relative to one another, for example, between 0 degrees and 20 degrees. The curvature and/or angle allows the clip 2411 to fit the contours of the patient's face in the region of the clip 2411.

The nasal interface 100 may include a sleeve 270. Each sleeve 270 may be preformed to have a curved shape along its length. In one example, each sleeve 270 may be preformed with two or more portions angled relative to each other, such as between 0 degrees and 20 degrees. The curvature and/or angle allows the sleeve to adapt to the contours of the patient's face or cheek in the region of the sleeve in use. Alternatively, the sleeve 270 may take the shape of a curved sleeve when engaged with the main ends 2011, 2021 of the headband 200 or the connector 2401.

The sleeve 270 provides a surface area with a relatively high friction surface material for frictional engagement with the face or facial skin of a user. The surface area is positioned to frictionally engage the facial cheek skin of the user. The surface area is at least localized to the band or band segment to be positioned on the cheek of the user. The surface area provided with the relatively high friction surface material may be a material that is smooth and comfortable to 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 2401.

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

The surface area 271 may be a surface that is more adjacent to a wider surface area of the patient interface than a surface area that is farther 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 2401 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 interface body 118. This provides a smooth transition between the nasal interface 100 and the headgear.

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. The sleeve 270 of each of these dimensions 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 prongs 111, 112 have an asymmetric nasal flow rather than a symmetric nasal flow.

Headgear for other forms of interface other than nasal cannula may include cheek supports 270 as described or similar at or near either side of the band of headgear for the interface, connected to the nasal interface, for frictional engagement with the face of the user to stabilize the mask at the cheek on the face. Such headgear may also include a single headgear adapted to extend in use along the patient's cheeks, over the ears and around the rear of the head, and with its ends including any suitable form of clip coupled to (or permanently attached to) the nasal interface at either side.

Referring to fig. 1A-1C, in the illustrated construction, the patient interface 10 includes a tube retaining clip 280. Tube retaining clip 280 may support patient tube 300 or other gas supply tube from a portion of patient interface 10. By supporting the patient conduit 300 or other gas supply tube from the nasal interface 100 or its vicinity, bending moments imparted to the patient conduit 300 or other gas supply tube 300 due to asymmetric flow through the first prong 111 and the second prong 112 and/or movement of the patient's head will be resisted by the tube retaining clip 280, thereby improving patient comfort.

In the illustrated construction, the tube retaining clip 280 includes a tubular body 281 for receiving and housing therein a portion of a patient catheter 300 or other gas supply tube.

In the illustrated construction, the tube retaining clip 280 supports the patient tube 300 or other gas supply tube from the headgear of the patient interface. In alternative constructions, the tube retaining clip 280 may support the patient tube 300 or other gas supply tube from a portion of the nasal interface 100 of the patient interface. For example, the tube retaining clip 280 may support the patient tube 300 or other gas supply tube from the interface body 118. In some constructions, the tube retaining clip 280 may support the patient interface from one or both of the wings 114, 115 of the nasal interface 100.

The hook 282 protrudes from the tubular body 281 to couple a strap or other member of the headgear. In this manner, the catheter 300 may be coupled or tethered to the headband 210 or headgear in use. If catheter 300 is pulled, force will be exerted on headband 210 rather than directly on cannula 100. This repositioning of force will reduce the likelihood that prongs 111 and 112 of nasal interface 100 will pop out of the patient's nostrils.

One or more tie-down points for the connecting tube retention clip 280 may be located on the headgear, preferably with at least two symmetrical tie-down points on either side of the headgear to increase usability.

It should also be appreciated that the tube retaining clip 280 may be removable from the patient tube 300 or other gas supply tube, or may be a permanent fitting on the patient tube or other gas supply tube.

Tube retaining clip 280 may be attached (removably or permanently) or retained to a portion of patient interface 10, such as an interface portion that provides a relatively more rigid region (e.g., to support patient catheter 300). The tube retaining clip may also be positioned or secured at a particular location on the patient catheter 300, for example, a predetermined location may be provided that holds the retaining clip in place.

In some constructions, one or both of the first prong 111 and the second prong 112 ensure that a gap is maintained between the outer surface of the prong and the patient's skin to avoid sealing between the nasal interface 100 and the patient. This provides a gas path for the flow of gas around the outer surfaces of the prongs 111, 112.

The patient interface 10 may have any one or more of the features and functions described in PCT publication No. WO2014/182179 or U.S. patent No. 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 include a fixation system of the type described in PCT publication No. WO2012/053910 or U.S. patent No. 10,238,828. The contents of these specifications are incorporated herein by reference in their entirety.

The nasal interface may have any one or more of the features described with respect to the nasal hole locator of U.S. patent No. 10,918,818. The contents of this specification are incorporated herein by reference in their entirety.

Referring to fig. 2, a patient interface 10 having the nasal interface 100 described with reference to fig. 1A-1D is shown. Additionally, at least one element configured or arranged to increase resistance to gas flow through the nasal interface or a portion thereof is provided.

First prong member 201, second prong member 202 and manifold member 203 are schematically illustrated in fig. 2 and are constructed or arranged to increase the resistance to gas flow through the respective first prong 111, second prong 112 and manifold 120.

The elements 201, 202, 203 used throughout may also be referred to as flow restrictors or flow restrictors.

Although fig. 2 shows first prong element 201, second prong element 202, and manifold element 203, in various configurations as detailed below, there may be a single element 201, 202, 203 in nasal interface 100, or there may be any combination of two elements (e.g., second prong element 202 and manifold element 203).

When present, the second prong element 202 is located within the second prong 112 and serves to increase the flow resistance of the gas flow through the second prong 112. The second fork element 202 can be positioned at or near the second base 136, at or near the second end 132, or at any location between the second end 132 and the second base 136.

In some constructions, the flow resistance provided by any of the elements 201, 202, 203 described herein may be such that very little (negligible) or no flow is allowed through the element.

When present, the manifold element 203 is positioned within the manifold chamber 125 and serves to increase the flow resistance of the gas flow through the gas manifold 120. Manifold element 203 is positioned between inlets for flow channels of respective first fork 111 and second fork 112, for example between first base 135 and second base 136. Thus, in a configuration where the gas inlet 121 is located on one side of the gas manifold 120, the flow of gas from the gas inlet 121 through the manifold chamber 125 will be restricted for one proximal prong and not for the other prong. In particular, in the case where the first fork 111 is close to the gas inlet 121, the gas flow is not restricted by the manifold element 203 to the first base 135, since the gas inlet 121 and the first base 135 are in fluid communication without gas passing through the manifold element 203. The flow of gas from the gas inlet 121 through the manifold chamber 125 to the second base 136 is limited by the manifold member 203 because the gas inlet 121 and the second base 136 are in fluid communication where gas must pass through the manifold member 203.

When present, the manifold element 203 divides the manifold chamber 125 into an upstream portion 141 and a downstream portion 142 located at either side of the manifold element 203. The upstream portion 141 is located on the gas inlet 121 side of the gas manifold 120.

When present, the first fork element 201 is positioned within the first fork 111 and serves to increase the flow resistance of the gas flow through the first fork 111. The first fork element 201 may be located at or adjacent to the first base 135, at or adjacent to the first end 131, or at any location between the first end 131 and the first base 135.

When present individually in the nasal interface 100, each of the elements 201, 202, 203 causes an asymmetric gas flow at the first prong 111 and the second prong 112 and thus at each naris. The asymmetric flow results in a pressure differential between the first nasal prongs 111 and the second nasal prongs 112, thereby resulting in a pressure differential between the patient's nares. Thus, a single first fork element 201, second fork element 202, or manifold element 203 may provide flow restriction to induce asymmetric gas flow at each fork 111, 112, respectively. Likewise, the combination of the second prong 202 and the manifold element 203 (the absence of the first prong 201) will result in a restriction of flow to the second prong 112, which will result in an asymmetric flow. However, the presence of first prong elements 201 and second prong elements 202 (or manifold elements 203) that similarly restrict gas flow at each of first prong 111 and second prong 112 will not create asymmetric gas flow. However, in some configurations, the elements 201, 202, 203 may be configured to restrict flow at different sizes so as to provide asymmetric flow even when there is a combination of flow restriction to the first fork 111 and the second fork 112.

In some constructions, the prongs closest to the gas inlet 121 are not limiting, as the gas flow is minimally disturbed by the geometry from the gas inlet 121 to the respective prongs. Thus, as in the case of fig. 2, the first nasal prongs 111 may be absent any first element 201. In some constructions, at least one of the second fork 112 and the gas manifold 120 is free of any elements or flow restrictions when the first fork element 201 is present. In some constructions, at least one of the first prong 111 and the gas manifold 120 is free of any elements or flow restrictions when the second prong element 202 is present. In some constructions, at least one of the first prong 111 and the second prong 112 is free of any elements or flow restrictions when the manifold element 203 is present. Each of the at least one element as described herein induces an asymmetric flow at the nostril of the patient. In an example, when the flow of gas is provided to the patient, each of the at least one element causes an asymmetric flow at the nostril of the patient, optionally during an inhalation phase of the patient, an exhalation phase of the patient, or during a respiratory cycle of the patient. In some configurations, the elements 201, 202, 203 passively cause flow restriction.

Although the elements 201, 202, 203 are shown as rectangular, these elements 201, 202, 203 may take any suitable form. Examples of this are provided below.

The flow restrictions provided by the elements 201, 202, 203 may take various forms depending on the desired flow difference between the tines. Referring to fig. 3A to 3C, the elements 201, 202, 203 take the form of plates or walls 205. The plate 205 is positioned or formed in the prongs 111, 112 or manifold chamber 125. The plate 205 is positioned across the path through which the gas flows. The plate 205 includes holes 207 to allow gas to flow therethrough. The apertures 207 formed in the first fork element 201, the second fork element 202, or the manifold element 203 provide a smaller opening than the flow channels and restrict the flow of gas therethrough.

In some constructions, the plate 205 is positioned substantially centrally across the passage through which the gas flows.

The hole 207 may be located in the center of the plate 205 or may be eccentric within the plate.

Referring to fig. 3B, the plate 205 has a surface facing the flow of gas (e.g., in an upstream direction) from the gas inlet 121. This is the inlet surface 211. The plate 205 has a surface facing in a direction opposite (e.g., downstream) the flow of gas from the gas inlet 121. This is the outlet surface 213. The holes 207 are formed to extend between the surfaces such that the plate 205 has a thickness.

The inlet surface 211 transitions between a flow-facing surface and a forming aperture 207 (e.g., a wall of aperture 207). In fig. 3B, the transition 214 between the inlet surface 211 and the bore surface 207 is a sharp corner transition 214. The sharp corner transition 214 may be substantially a right angle formed between the two surfaces. Alternatively, the transition may be formed as a rounded or chamfered edge. The equivalent fillet or chamfer angle from the inlet surface 211 to the chamfered sharp corner transition 214 has an angle between about 75 ° and 110 °. The sharp corners 214 cause disruption of the gas flow, for example, turbulence. This results in the elements 201, 202, 203 causing additional disruption to the flow.

The outlet surface 213 transitions between the aperture 207 and the wake. In fig. 3B, the transition 216 between the aperture 207 and the outlet surface 213 is a smooth angled transition 216 with rounded or chamfered edges. The equivalent fillet or chamfer angle from the outlet surface 213 to the chamfered smooth angle transition 216 has an angle between about 30 deg. and 75 deg.. The smooth angle 216 allows the gas flow to exit the aperture 207 to fill the flow channels through the elements 201, 202, 203.

Referring to fig. 3C, the transition 215 between the inlet surface 211 and the bore surface 207 is a smooth angle inlet transition 215. Thus, it is similar to the smooth angle outlet transition 216. The equivalent fillet or chamfer angle from the inlet surface 211 to the chamfered smooth angle transition 215 has an angle between about 30 deg. and 75 deg..

In some constructions, the sharp angle inlet transition 214 or the smooth angle inlet transition 215 has a greater angle or chamfer angle than the smooth angle outlet transition 216. This ensures that the gas flow is disturbed when entering the aperture 207.

The variation of the smooth and sharp transitions 214, 215, 216 results in the elements 201, 202, 203 having a higher discharge coefficient than the equivalent plate 205 of the holes 207 having the same inner diameter.

The smooth angular transition 216 at the outlet surface 213 may ensure that gas flow through the first prong 111 or the second prong 112 with the first prong 201 or the second prong 202 towards the manifold chamber 125 is less restricted, e.g., during patient exhalation. Thus, accumulation of gas in either nostril of the patient is avoided.

In some constructions, the diameter of the aperture 207 may decrease at one location, e.g., near the outlet surface 213, such that a change in cross-section creates an increased pressure drop relative to the inlet surface 211 having a larger diameter, and thus smoother into the elements 201, 202, 203. This variation in the diameter of the aperture 207 may be formed as a nozzle.

When formed as an orifice, the aperture 207 may be any shape, such as circular, or may be triangular, square, or any polygonal shape. A plurality of holes 207 may be formed in the plate 205. In some examples, a non-perforated but non-contiguous plate 205 with one or more small gaps may be provided, or a contiguous wall with a perforation pattern may be provided. A porous medium such as a filter may be used as the plate 205. Gaps, slits or cuts may be formed in the plate 205 extending longitudinally, either vertically or horizontally, with respect to the plate 205 itself. Perforated walls or panels 205 may have the benefit of reducing acoustic noise generation.

In some constructions, the elements 201, 202, 203 may have varying surface textures in the gas flow path to provide a pressure drop across the elements 201, 202, 203. The substantially coarser areas may have an increased pressure drop.

In some configurations, the first prong element 201, the second prong element 202, or the manifold element 203 may be in the form of a valve to cause a pressure drop to restrict flow. Referring to fig. 4, a patient interface 10 is shown having the nasal interface 100 described with reference to fig. 1A-1D and fig. 2. Manifold member 203 includes a manually adjustable flow restrictor 220.

In this configuration, the gas manifold 120 has a manifold element 203 that is connected to or formed with a flow restrictor 220 adjustment mechanism that can be actuated from outside the gas manifold 120.

In some constructions, the flow restrictor 220 has a slider 221 disposed on the exterior of the gas manifold 120 for adjusting the position of the body 222 of the flow restrictor 220 within the manifold chamber 125. The body 222 of the flow restrictor provides a variable opening through the manifold chamber 125 by varying how much of the flow path cross-sectional area is "open" or effective and how much of the gas flow passes through the manifold member 203 to the second prong 112. In some constructions, the manifold chamber 125 tapers between the first base 135 and the second base 136. The flow restrictor 220 may be movable along the manifold chamber 125, for example in a direction toward or away from the gas inlet 121, such that the passage in the manifold chamber 125 between the first base 135 and the second base 136 varies. In use, by actuating the slider 221 along the outside of the gas manifold 120, the flow restrictor 220 is moved closer to the first prong 111 to block flow to the second prong 112. The degree of restriction may be greater/lesser depending on the size or height of the body 222. Conversely, moving the element toward the second prong 112 reduces the restriction effect on the flow to the second prong 112 because the gas flow path in the manifold chamber 125 is less restricted.

In some arrangements, the flow restrictor 220 may be moved further into the manifold chamber 125 to provide a smaller opening, such as vertical movement. Thus, the cross-sectional area of the flow path is varied by the body 222, leaving a smaller effective aperture for flow. Both of these movements may be applied in a single flow restrictor 220.

Referring to fig. 5, a patient interface 10 is shown having the nasal interface 100 described with reference to fig. 1A-1D, 2 and 4. The flow restrictor 220 of the manifold member 203 is replaced by a rotatable restrictor 225.

The rotatable restrictor 225 is arranged to extend through the gas manifold 120 such that an inner portion is located within the manifold chamber 125 and an outer portion is located outside of the gas manifold 120. The rotatable restrictor 225 is adjustable to increase or decrease the flow of gas through the manifold chamber 125 downstream of the manifold member 203. The rotatable restrictor 225 is a screw to allow rotation to move the rotatable restrictor 225 further into the manifold chamber 125 to effectively reduce the aperture through which the gas flows or increase the aperture through which the gas flows. The adjustment is made by rotating an outer portion of the rotatable limiter that is located outside the gas manifold 120. Thus, the flow of gas from gas inlet 121 is limited by rotatable regulator 225 at second prong 112, and the amount of limitation may vary.

The threads of the rotatable limiter 225 help to hold the manifold element 203 in place, allowing the clinician to safely construct the nasal interface 100 as desired without risk of the manifold element 203 being bumped or displaced at a later point in time.

The valve of the manifold member 203 (e.g., the flow restrictor 220 or the rotatable restrictor 225) may be controlled manually or electronically.

Although reference is made to manifold member 203 in fig. 4 and 5, either first fork member 201 or second fork member 202 may utilize such a valve. Further, the sliding or rotating functions of the flow restrictor 220 or rotatable restrictor 225 valve may be combined.

Referring to fig. 6, a patient interface 10 having a nasal interface 100 is shown. This arrangement is as described with reference to fig. 1A to 1D, and may optionally be combined with other configurations described herein.

In this configuration, manifold openings 230 are formed in the wall of gas manifold 120. The manifold opening 230 allows a portion of the gas to pass through it, exiting the manifold chamber 125. The manifold opening 230 may include one or more holes.

In this configuration, there is a manifold element 203, such as described elsewhere herein. Thus, the manifold chamber 125 is divided into an upstream portion 141 and a downstream portion 142 at either side of the manifold element 203. The upstream portion 141 is located on the gas inlet 121 side of the manifold chamber 125. Manifold opening 230 is positioned in downstream portion 142.

In some constructions, the manifold opening 230 is positioned on a wall of the gas manifold 120 generally opposite the gas inlet 121. In other constructions, the manifold opening 230 is positioned on a wall of the gas manifold 120 generally opposite the second base 136. In some constructions, these may be the same location.

As described above with reference to fig. 2, the manifold element 203 is a restriction to the gas flow. Thus, the upstream portion 141 is typically at a higher pressure because the flow of gas is restricted by the manifold member 203 into the downstream portion 142. This is especially true during patient inspiration. Thus, more gas flow will travel through the unobstructed/unrestricted first prong 111 than the second prong 112.

Upon expiration of the patient, gas may leak into the surrounding environment where the second prong 112 is unsealed. The gas may also flow back into the gas manifold 120 by flowing back through the second prongs 112. In the presence of the manifold member 203, this may cause an increase in pressure in the downstream portion 142 because the flow of gas may be restricted from passing through the manifold member 203. Manifold openings 230 allow some of the gas to be vented to the environment. As such, in some configurations, the amount of pressure experienced in the nasal interface 100 may be prevented from reaching undesirable levels.

Factors that may cause an increase in pressure in the downstream portion 142 also include excessive occlusion of the patient's nostrils. In some cases, this may be due to incorrect interface size selection.

The manifold opening 230 may serve as an exhalation outlet.

Some venting of the gas flow through the manifold openings 230 may occur during inhalation such that not all of the gas flowing from the upstream portion 141 to the downstream portion 142 passes through the second prong 112. However, even if a certain amount of gas flow does not enter the second prong 112, but is expelled into the environment through the manifold opening 230, the increased pressure will have the effect of reducing the flow of exhaled gas from the nostril associated with the second prong 112. This has the benefit of increasing the asymmetry, which is also achieved by positioning the manifold element 203.

Referring to fig. 7, a patient interface 10 having a nasal interface 100 is shown. The arrangement is as described with reference to fig. 6, including manifold openings 230 formed in the wall of the gas manifold 120.

In this configuration, manifold opening 230 is configured to connect to pressure drop member 232. The pressure drop member 232 is configured to prevent overpressure from occurring. This contributes to possible overpressure in the downstream portion 142 of the manifold chamber 125, such as described above with reference to the manifold opening 230 itself.

A variety of configurations are possible for pressure drop member 232. In one configuration, the pressure drop member 232 is a porous medium, such as a filter. In another configuration, the pressure drop member 232 is a nozzle. Other means 232 that cause a generally known pressure drop may also be used.

In some constructions, the pressure drop member 232 is an auxiliary tube. The auxiliary tube may be a nasogastric tube, i.e. extending to at least one of the first prong 111 or the second prong 112.

In another configuration, the pressure drop member 232 is a valve. The valve may be a pressure relief valve having a defined pressure threshold at which the valve opens. In other constructions, the valve depends on the flow rate to increase the flow rate based on the flow-pressure relationship. Thus, the pressure in the downstream portion 142 is controlled and allowed to release in a controlled manner while maintaining an asymmetric flow.

For clarity, in some constructions, the manifold opening 230 and the pressure drop member 232 may be combined such that the manifold opening 230 is a nozzle, valve, porous medium, auxiliary tube, or other member itself, rather than an opening to such a member. In one example, the manifold opening 230 and pressure drop member 232 are one-way valves that allow insertion of an auxiliary tube (e.g., nasogastric tube). The one-way valve may be a flexible valve.

The pressure drop member 232 may be manually or electronically controllable. For example by means of a valve, which may be controllable to open or close in response to a pressure threshold.

In some configurations, the pressure-reducing member 232 is a Bubble CPAP (BCPAP) bubbling chamber configured to control pressure. The use of bubble CPAP allows for an indication of the minimum pressure observed. For example, if there is a blister when set to 2cmH ₂ O, this indicates Positive End Expiratory Pressure (PEEP). Thus, a clinician or caregiver may configure the pressure drop member 232 to vary pressure or flow. The flow and pressure may be independently configured.

In some configurations, leakage or venting of gas into the ambient environment at the non-sealing prongs 111, 112 and/or at the manifold openings 230 reduces Positive End Expiratory Pressure (PEEP). Thus, the treatment profile (therapy profile) varies due to the function of the exhaust.

In the configuration of fig. 6 and 7, the manifold element 203 has been described. However, there need not be a manifold element 203 as described. Conversely, in some configurations, where the preferential flow is provided to the first prong 111 or the second prong 112, the manifold opening 230 may still be implemented to assist the pressure while maintaining the asymmetric flow. Further, in some configurations including manifold openings 230, there may be first fork element 201 or second fork element 202, or other features to cause asymmetric flow as described throughout. The manifold openings 230 and optional pressure drop members 232 reduce the risk of pressure damage, for example, due to improper fit.

Referring to fig. 8, a patient interface 10 having a nasal interface 100 is shown. This arrangement is as described with reference to figure 2.

In this arrangement, the manifold element 203 is formed as a one-way valve 204. Thus, when the check valve 204 is closed, a portion of the flow restriction acts to prevent flow from the downstream portion 142 from flowing into the upstream portion 141 through the manifold member 203.

The check valve 204 may also function as a flow restriction, such as described elsewhere herein with reference to the manifold element 203. Thus, the valve may provide a restriction to flow, for example having a smaller opening than the cross-section of the manifold chamber 125, to reduce gas flow from the upstream portion 141 to the downstream portion 142. Thus, an asymmetric flow is provided between the first fork 111 and the second fork 112.

In some constructions, the one-way valve 204 is a duckbill valve.

This arrangement may be combined with the manifold openings 230 shown in fig. 8 and described above with reference to fig. 6, as pressure may build up within the downstream portion 142 of the manifold chamber 125 by implementing the check valve 204. Likewise, the pressure drop member 232 described with reference to FIG. 7 may also be implemented.

Fig. 9 illustrates an exemplary patient interface 10 that includes a nasal interface 100 having a first nasal prong 111 and a second nasal prong 112. The components of the patient interface 10 are similar to those described with reference to fig. 1A-1D, and like reference numerals are used herein for like features.

The nasal interface includes a gas manifold 120 that includes a first gas inlet 121 and a second gas inlet 122. The gas manifold 120 forms a manifold chamber 125 to allow gas to pass therethrough. The nasal interface 100 includes a flow altering feature to provide an asymmetric flow at one of the prongs 111, 112.

The first and second prongs 111, 112 are in fluid communication with the first and second gas inlets 121, 122 through the gas manifold 120. The first gas inlet 121 is positioned at the gas manifold 120 such that the first prong 111 is closer to the first gas inlet 121 and the second prong 112 is farther from the first gas inlet 121. The second gas inlet 122 is positioned at the gas manifold 120 such that the second prong 112 is closer to the second gas inlet 122 and the first prong 111 is further from the second gas inlet 122.

In some constructions, the positions of the prongs are reversed such that the second prong 112 is closer to the first gas inlet 121 and the first prong 111 is closer to the second gas inlet 122.

In some constructions, the first gas inlet 121 and the second gas inlet 122 are located at opposite sides of the gas manifold 120. In other constructions, the first gas inlet 121 and the second gas inlet 122 are disposed adjacent to one another.

The first prong 111 and the second prong 112 have flow passages to allow gas to flow therethrough. The flow paths of the first and second prongs 111 and 112 are formed by their respective inner walls.

The gas manifold 120 is in fluid communication with a gas delivery conduit 300 that is connected to the gas manifold 120 through a first gas inlet 121 and a second gas inlet 122.

In some constructions, the gas delivery conduit 300 has a first gas delivery conduit 301 connected to the first gas inlet 121, and a second gas delivery conduit 302 connected to the second gas inlet 122. The gas delivery conduit 300 may be divided into a first delivery conduit 301 and a second delivery conduit 302, for example by a Y-piece. In some other configurations, the first gas delivery conduit 301 and the second gas delivery conduit 302 are directly connected to the flow generator(s). The gas manifold 120 can be removably attached to or integrally molded onto the gas delivery conduit 300, the first gas delivery conduit 301, or the second gas delivery conduit 302.

The first gas inlet 121 and the second gas inlet 122 are openings, holes or ports in the gas manifold 120 for releasable or permanent connection to a conduit, such as the first gas delivery conduit 301 or the second gas delivery conduit 302. In some arrangements, the first gas inlet 121 and the second gas inlet 122 may form a tube or channel extending from or as part of the gas manifold 120. In some arrangements, the first gas inlet 121 and the second gas inlet 122 have fastening or connecting means for securing to the conduit.

In the illustrated configuration, the gas flow passes from the first gas delivery conduit 301 through the gas inlet 121, through the manifold chamber 125 to the first prong 111 and the second prong 112, and through their respective flow passages to the nostrils of the patient. The flow of gas also passes from the second gas delivery conduit 302 through the gas inlet 122, through the manifold chamber 125 to the second prong 112 and the first prong 111, and through their respective flow passages to the nostrils of the patient. However, in some configurations, gas may flow in an opposite direction, such as during exhalation, wherein gas flow from the patient's nares may flow through the first and second prongs 111, 112 into the gas manifold 120.

In the illustrated construction, the first and second prongs 111, 112 may be formed as part of the interface body 118. The interface body 118 is a facial mount for engaging the patient's face. The first and second prongs 111, 112 are integrally molded with or removably attached to the interface body 118.

The interface body 118 component may be connected to or joined to the gas manifold 120 component, or may be integrally formed with or permanently joined to the gas manifold 120 component.

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

In the illustrated construction, the first nasal prongs 111 have openings at their top or distal ends 131 for delivering gas from the gas manifold 120. The gas delivered through the first nasal prongs 111 exits the first nasal prongs 111 via the first ends 131. The first nasal prong 111 has a first base 135 at an end of the first nasal prong 111 opposite the first end 131. The first base 135 is another opening and is connected to the gas manifold 120 and allows gas to flow from the manifold chamber 125 to the first fork 111. The first base 135 may be integrally formed with or removably connected to the interface body 118.

The second nasal prongs 112 have openings at their top or distal ends 132 for delivering gas from the gas manifold 120. The gas delivered through the second nasal prongs 112 exits the first nasal prongs 112 via the second ends 132. The second prong 112 has a second base 136 at an end of the second prong 112 opposite the second end 132. The second base 136 is another opening that connects to the gas manifold 120 and allows gas to flow from the manifold chamber 125 to and through the second prong 112. The second base 136 may be integrally formed with or removably connected to the interface body 118.

The first and second prongs 111, 112 may have any suitable shape to seal or insert into the nostrils of the patient. For example, in one configuration, the first and second prongs 111, 112 may be substantially tubular and may be sized larger than the nostrils of the patient, but may be soft or flexible to deform and seal with the nostrils upon insertion into the nostrils. In another configuration, the first and second prongs 111, 112 may be soft or flexible to deform and sized to form a non-sealing arrangement with the nostrils. For example, the first and second prongs 111, 112 may not enter the nostrils, but are located proximally. In some constructions, the prongs 111, 112 are softer or more flexible than the interface body 118.

The first and second gas delivery conduits 301, 302, or the first or second gas inlets 121, 122 may be configured to provide asymmetric flow to the first and second prongs 111, 112.

In some constructions, such as when the passageways are circular, the flow altering features providing asymmetric flow include conduits 301, 302 or inlets 121, 122 having different (unequal) internal passageway diameters (lumens). The difference in diameter results in different characteristics of the gas flow through the first gas inlet 121 and the second gas inlet 122 and thus to the respective proximal nasal prongs 111, 112.

In some constructions, the diameter of the internal passageway of the first gas delivery conduit 301 or the first gas inlet 121 is greater than the diameter of the internal passageway of the second gas delivery conduit 302 or the second gas inlet 122. Alternatively, the diameter of the internal passageway of the first gas delivery conduit 301 or the first gas inlet 121 is smaller than the diameter of the internal passageway of the second gas delivery conduit 302 or the second gas inlet 122.

In some configurations, such as when the passageway is non-circular in shape, the flow altering features that provide asymmetric flow include conduits 301, 302 or inlets 121, 122 having different internal passageway cross sections (lumens). Although not limited thereto, non-circular shapes include elliptical shapes, straight-sided shapes, or any polygonal shape. A combination of a circular internal passage for one of the conduits 301, 302 or inlets 121, 122 and a non-circular shape for the other of the conduits 301, 302 or inlets 121, 122 may also be provided. The difference in cross-section between the conduits 301, 302 or inlets 121, 122 results in different characteristics of the gas flow through the first and second gas inlets 121, 122 and thus to the respective proximal nasal prongs 111, 112.

In some constructions, the cross-section of the internal passageway of the first gas delivery conduit 301 or the first gas inlet 121 is greater than the cross-section of the internal passageway of the second gas delivery conduit 302 or the second gas inlet 122. Alternatively, the cross-section of the internal passageway of the first gas delivery conduit 301 or the first gas inlet 121 is smaller than the cross-section of the internal passageway of the second gas delivery conduit 302 or the second gas inlet 122.

In some constructions, the flow altering features that provide asymmetric flow include conduits 301, 302 or inlets 121, 122 having internal passages (lumens) of different lengths. For example, the gas delivery conduit 300 may be separated at different portions to provide a first gas delivery conduit 301 and a second gas delivery conduit 302. Alternatively or additionally, in some constructions, the length of the conduit from the Y-piece may have different lengths for the first gas delivery conduit 301 and the second gas delivery conduit 302. Alternatively or additionally, the first gas inlet 301 and the second gas inlet 302 may also be formed as tubes (which are connected to the gas delivery conduits 301, 301) having different lengths extending from the gas manifold 120. The difference in length results in different characteristics of the gas flow through the first gas inlet 121 and the second gas inlet 122 and thus to the respective proximal nasal prongs 111, 112.

In some constructions, the length of the first gas delivery conduit 301 or the first gas inlet 121 is longer than the length of the second gas delivery conduit 302 or the second gas inlet 122. Alternatively, the length of the first gas delivery conduit 301 or the first gas inlet 121 is shorter than the length of the second gas delivery conduit 302 or the second gas inlet 122.

In some configurations, the flow altering features that provide asymmetric flow include conduits 301, 302 or inlets 121, 122 with internal flow modifying elements or relief (relief) features. These elements may include, but are not limited to, fins, baffles, protrusions, dividers, vanes, or any other restriction. The flow modifying element may differ between the conduits 301, 302 or the inlets 121, 122, or may be present in only one of the conduits 301, 302 or the inlets 121, 122. The flow modifying elements result in different characteristics of the gas flow through the first and second gas inlets 121, 122 and thus to the respective proximal nasal prongs 111, 112. The flow modifying elements may be elements as described elsewhere herein, such as those for the first fork 111 and the second fork 112.

In some constructions, the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 includes an internal flow modifying element (or pressure relief feature), while the internal passage of the second gas delivery conduit 302 or the second gas inlet 122 does not include an internal flow modifying element (or pressure relief feature). Alternatively, the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 does not comprise an internal flow modifying element, while the internal passage of the second gas delivery conduit 302 or the second gas inlet 122 comprises an internal flow modifying element. Alternatively, the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 comprises an internal flow modification element which has a greater influence on the flow of the internal flow modification element of the internal passage of the second gas delivery conduit 302 or the second gas inlet 122. Alternatively, the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 comprises an internal flow modification element that has a smaller influence on the flow of the internal flow modification element of the internal passage of the second gas delivery conduit 302 or the second gas inlet 122.

Referring to fig. 10, a patient interface 10 having a nasal interface 100 is shown. The arrangement is as described with reference to fig. 9, comprising a first gas inlet 121 and a second gas inlet 122.

In addition, in this configuration, the first gas delivery conduit 301 and the second gas delivery conduit 302 are connected to different gas streams. Thus, the first gas delivery conduit 301 and the second gas delivery conduit 302 are not separated from the single gas delivery conduit 300.

The first gas delivery conduit 301 is connected to (i.e., in fluid communication with) a first gas stream 303, and the second gas delivery conduit 302 is connected to (i.e., in fluid communication with) a second gas stream 304. The first gas flow 303 and the second gas flow 304 have different flow characteristics as flow altering features, such as different flow rates or even flow directions. Thus, the different flow characteristics of the first and second gas flows 303, 304 cause asymmetric flow at the first and second prongs 111, 112 due to the different flows entering the gas manifold 120 proximate to the first and second prongs 111, 112. For example, a different gas pressure is established near the inlet (base 135, 136) of each fork 111, 112. In case one of the first gas flow 303 or the second gas flow 304 has a negative pressure, e.g. suction, a different gas pressure is created near the inlet (base 135, 136) of each fork 111, 112, resulting in an asymmetric flow.

In some configurations, the flow altering feature that provides an asymmetric flow includes the first gas flow 303 delivering the gas flow at a higher rate than the second gas flow 304 and thus to the corresponding proximal prongs 111, 112. Alternatively, the first gas stream 303 delivers the gas stream and thus to the respective proximal fork 111, 112 at a lower rate than the second gas stream 304.

In some configurations, the flow altering features that provide asymmetric flow include a first gas flow 303 having a gas flow at positive pressure relative to ambient pressure and a second gas flow 304 having a gas flow at negative pressure. Alternatively, the first gas stream 303 has a gas stream at negative pressure, while the second gas stream 304 has a gas stream at positive pressure.

In some configurations, to prevent excessive mixing of the first gas stream 303 and the second gas stream 304, a manifold element 203 as described elsewhere herein may be disposed between the first prong 111 and the second prong 112, and thus between the first inlet 121 and the second inlet 122. The manifold element 203 may partially restrict flow or may completely restrict flow.

Referring to fig. 11, a patient interface 10 having a nasal interface 100 is shown. The arrangement is as described with reference to fig. 9, comprising a first gas inlet 121 and a second gas inlet 122.

In addition, in this configuration, first fork element 201, second fork element 202, manifold element 203, first gas inlet element 209, and second gas inlet element 208 are provided as flow altering features for increasing resistance to gas flow therethrough. The first fork element 201, the second fork element 202, and the manifold element 203 may be the same as those described elsewhere herein, for example with reference to fig. 2.

Although fig. 11 shows first fork element 201, second fork element 202, manifold element 203, first (gas) inlet element 209, and second (gas) inlet element 208 having configurations as described in detail below, there may be a single element 201, 202, 203, 208, 209, or any combination of elements in nasal interface 100.

The elements 201, 202, 203, 208, 209 used throughout may also be referred to as flow restrictors or flow restrictors.

When present, second prong element 202 is positioned within second prong 112 and is configured to increase resistance to gas flow through second prong 112. The second fork element 202 can be positioned at or near the second base 136, at or near the second end 132, or at any location between the second end 132 and the second base 136.

In some constructions, the flow resistance provided by any of the elements 201, 202, 203, 208, 209 described herein may be such that very little (e.g., negligible) or no flow is allowed through the element.

When present, the manifold element 203 is positioned within the manifold chamber 125 and serves to increase the flow resistance of the gas flow through the gas manifold 120. The manifold element 203 is positioned between inlets for flow channels of the respective first and second prongs 111, 112, for example between the first and second bases 135, 136. Similarly, manifold member 203 is positioned between first gas inlet 121 and second gas inlet 122. Thus, since the first gas inlet 121 is positioned substantially at one side of the gas manifold 120 near the first prong 111, the flow of gas from the first gas inlet 121 through the manifold chamber 125 will be restricted for the second prong 112 positioned on the opposite side of the manifold element 203, but not for the other first prong 111 near the first gas inlet 121. Also, since the second gas inlet 122 is positioned substantially at the other side of the gas manifold 120 near the second prong 112, the flow of gas from the second gas inlet 122 through the manifold chamber 125 will be restricted for the first prong 111 positioned on the opposite side of the manifold element 203, but not for the second prong 112 near the second gas inlet 122.

When present, the first fork element 201 is positioned within the first fork 111 and serves to increase the flow resistance of the gas flow through the first fork 111. The first fork element 201 may be positioned at or adjacent to the first base 135, at or adjacent to the first end 131, or at any location between the first end 131 and the first base 135.

When present, the first gas inlet element 209 is positioned proximate to the first inlet 121 and serves to increase the flow resistance of the gas flow through the first inlet 121 (e.g., from the first gas delivery conduit 201 into the manifold chamber 125). The first inlet element 209 may be positioned at any location within the gas manifold 120 between the first gas delivery conduit 301 and a location prior to the first base 135. In some arrangements, where the first gas inlet 121 is a tube or channel, the first inlet element 209 is positioned within the channel or at an end of the channel.

When present, the second gas inlet element 208 is positioned proximate to the second inlet 122 and serves to increase the flow resistance of the gas flow through the second inlet 122 (e.g., from the second gas delivery conduit 302 into the manifold chamber 125). The second inlet element 208 may be positioned at any location within the gas manifold 120 between the second gas delivery conduit 302 and a location prior to the second base 136. In some arrangements, where the second gas inlet 122 is a tube or channel, the second inlet element 208 is positioned within the channel or at an end of the channel.

Each of the elements 201, 202, 203, 208, 209, alone or in combination, causes an asymmetric gas flow through the first prong 111 and the second prong 112 and thus at each naris. Thus, a single first fork element 201, second fork element 202, manifold element 203, second inlet element 208, or first inlet element 209 may provide flow restriction to correspondingly induce asymmetric gas flow through each fork 111, 112. In the case of the second inlet element 208 or the first inlet element 209, the flow restriction caused by the individual elements 208, 209 has similar effects to the characteristics of the gas delivery conduits 301, 302 or the gas inlets 121, 122 described with reference to fig. 9. Thus, the flow through the first gas inlet 121 or the second gas inlet 122 will be different from the other gas inlets and thus cause a different flow to be provided to the proximal nasal prongs 111, 112.

In some constructions, there are single elements 201, 202, 203, 208, 209, while there are no other elements. Thus, at least one of first prong 111, second prong 112, manifold chamber 125, first inlet 121, or second inlet 122 is not restricted by the flow of elements 201, 202, 203, 208, 209, for example.

The combination of two or more elements 201, 202, 203, 208, 209 will also result in a restriction of the flow to at least one of the first fork 111 or the second fork 112, which will cause an asymmetric flow.

While the magnitude of the flow restriction through each of the elements 201, 202, 203, 208, 209 varies to allow asymmetric flow at the tines 111, 112 in various combinations, some combined non-limiting explanations are as follows:

1) The first inlet element 209 in combination with the second inlet element 208 are each configured to increase the flow resistance of the gas flow entering the gas manifold 120 through the first gas inlet 121 and the second gas inlet 122, respectively. Each of the first inlet element 209 and the second inlet element 208 have different characteristics to affect flow in different ways. Thus, the flow to each prong 111, 112, and thus each naris, is asymmetric.

In this arrangement, in some constructions, there is no first fork element 201, second fork element 202, or manifold element 203.

2) The first inlet element 209, in combination with the manifold element 203, are each configured to increase the flow resistance of the gas flow therethrough. Thus, the flow through the first gas inlet 121 to the first fork 111 is limited by the first inlet element 209. However, the manifold member 203 also ensures that flow across the manifold chamber 125 to the first fork 111 through the second gas inlet 122 is also restricted. There is no resistance (or less resistance) to flow from the second gas inlet 122 to the second prong 112. Thus, the flow to each prong 111, 112, and thus each naris, is asymmetric.

In this arrangement, in some constructions, there is no first fork element 201, second fork element 202, or second inlet element 208.

3) The second inlet element 208, in combination with the manifold element 203, is each configured to increase the flow resistance of the gas flow therethrough. Thus, flow through the second gas inlet 122 to the first prong 112 is restricted by the second inlet element 208. However, the manifold element 203 also ensures that flow across the manifold chamber 125 to the second fork 112 through the first gas inlet 121 is also restricted. There is no resistance (or less resistance) to flow from the first gas inlet 121 to the first fork 111. Thus, the flow to each prong 111, 112, and thus each naris, is asymmetric.

In this arrangement, in some constructions, there is no first fork element 201, second fork element 202, or first inlet element 209.

4) The first fork element 201 and the second fork element 202 in combination are each configured to increase the flow resistance of the gas flow entering the first fork 111 and the second fork 112, respectively. Each of the first fork element 201 and the second fork element 202 have different characteristics in order to affect the flow in different ways. Thus, the flow to each prong 111, 112, and thus each naris, is asymmetric.

In this arrangement, in some constructions, there is no first inlet element 209, second inlet element 208, or manifold element 209.

5) The first inlet element 209, in combination with the manifold element 203 and the first fork element 201, are each configured to increase the flow resistance of the gas flow therethrough. Thus, the flow through the first gas inlet 121 to the first fork 111 is limited by the first inlet element 209 and the first fork element 201. However, the manifold member 203 ensures that flow across the manifold chamber 125 to the first fork 111 through the second gas inlet 122 is also restricted. There is no resistance (or less resistance) to flow from the second gas inlet 122 to the second prong 112. Thus, the flow to each prong 111, 112, and thus each naris, is asymmetric.

In this arrangement, in some constructions, there is no second binary element 202 or second inlet element 208. In some arrangements, the manifold element 203 may be removed with the first fork element 201 performing a similar function.

6) The second inlet element 208 in combination with the manifold element 203 and the second fork element 202 are each configured to increase the flow resistance of the gas flow therethrough. Thus, flow through second gas inlet 122 to second prong 112 is restricted by second inlet element 208 and second prong element 202. However, the manifold element 203 also ensures that flow across the manifold chamber 125 to the second fork 112 through the first gas inlet 121 is restricted. There is no resistance (or less resistance) to flow from the first gas inlet 121 to the first fork 111. Thus, the flow to each prong 111, 112, and thus each naris, is asymmetric.

In this arrangement, in some constructions, there is no first fork element 201 or first inlet element 209. In some arrangements, manifold element 203 may be removed and second prong 202 performs a similar function of restricting flow from first gas inlet 121 to second prong 112.

Although the elements 201, 202, 203 are shown as rectangular, these elements 201, 202, 203, 208, 209 may take any suitable form. For example, these elements may be an orifice plate with a single orifice, an orifice plate with multiple orifices, a venturi throat, or a nozzle. Other examples are provided in the present disclosure.

The present configuration as described with reference to fig. 11 may be combined with any other portion of the present disclosure. For example, the form of the elements (e.g., holes 207 formed in the plate or wall 205 described with reference to fig. 3A-3C) may be applied to the elements 201, 202, 203, 208, 209 of the present construction. Likewise, a rotatable restrictor 225 as described with reference to fig. 4 and 5 or a manual flow restrictor 220 with a slider 221 may be equally applied to the elements 201, 202, 203, 208, 209 of the present construction. The flow rate variation of the first gas stream 303 and the second gas stream 304 may be applied in combination with the present configuration. The manifold openings 230 and optional pressure drop members 232 described with reference to fig. 6-8 are equally applicable to the present configuration.

Referring to fig. 12, a patient interface 10 having a nasal interface 100 is shown. This arrangement is as described with reference to figure 1.

Additionally, in this configuration, the gas delivery conduit 300 is in fluid communication with the first gas stream 303, as described with reference to fig. 10 and the first gas delivery conduit 301. The first gas stream 303 provides a gas stream having a particular set of characteristics (e.g., flow rate or flow velocity).

The nasal interface 100 of this configuration also includes an auxiliary gas delivery conduit 305. The auxiliary gas delivery conduit 305 is smaller than the gas delivery conduit 300, e.g., the inner diameter of the inner lumen of the auxiliary gas delivery conduit 305 is smaller than the inner diameter of the inner lumen of the gas delivery conduit 300. The auxiliary gas delivery conduit 305 is smaller than the first fork 111. For example, the inner diameter of the inner cavity of the auxiliary gas delivery conduit 305 is smaller than the inner diameter of the flow path of the first fork 111.

The secondary gas delivery conduit 305 is connected (in fluid communication) with a second gas stream 304 as described with reference to fig. 10. Thus, the second gas stream 304 has different characteristics than the first gas stream 303.

An auxiliary gas delivery conduit 305 is located in the gas delivery conduit 300 and extends into the manifold chamber 125. The auxiliary gas delivery conduit 305 terminates in the first nasal prong 111 and thus has a gas outlet opening into the first nasal prong 111. Since the secondary gas delivery conduit 305 is smaller than the first fork 111 and the gas delivery conduit 300, it does not block the conduit and also allows the first gas stream 303 to flow through the conduit.

The second gas flow 304 through the auxiliary gas delivery conduit 305 causes an asymmetric flow at the first prong 111 and the second prong 112, as the different gas characteristics are directed only to the first prong 111 and thus to a single naris of the patient. The gas flow from the first gas flow 303 is directed to the second fork 112 without any flow restriction.

The different gas characteristics of the first gas flow 303 and the second gas flow 304 may also be negative pressure as described with reference to fig. 10. Thus, a lower dynamic pressure is provided at one of the nasal prongs 111, 112.

In some constructions, the auxiliary gas delivery conduit 305 is positioned external to the gas delivery conduit 300 and/or extends parallel to the gas delivery conduit 300. In some configurations, the secondary gas delivery conduit 305 is in fluid communication with the flow generator at an input, and in other configurations, the secondary gas delivery conduit 305 is in fluid communication with the gas delivery conduit 300 at an input, wherein a characteristic of the secondary gas delivery conduit 305 causes a different flow at an output thereof than the gas delivery conduit 300. In some constructions, the auxiliary gas delivery conduit 305 has its outlet at the first end 131 of the first prong 111, alternatively the auxiliary gas delivery conduit 305 extends to the second prong 112 and has its outlet there, thus causing an asymmetric flow between the prongs 111, 112.

Referring to fig. 13, a patient interface 10 having a nasal interface 100 is shown. The arrangement is similar to that described with reference to fig. 1.

In this configuration, the nasal interface 100 includes a flow directing element 240 to provide asymmetric gas flow to the first prong 111 and the second prong 112.

The flow guiding element 240 is formed at or near the gas inlet 121. The flow guiding element 240 is formed as a sub-channel to guide the gas flow to the first fork 111. The flow directing element 240 directs the gas flow from the gas delivery conduit 300 into the first fork guide flow 243. Thus, a majority of the gas flow from the gas delivery conduit 300 is directed into the first prongs 111 and into the nostrils of the patient.

In this configuration, the flow directing element 240 is formed as a curved channel having an inlet end 246 facing the gas delivery conduit 300 and an outlet end 247 facing the first end 131 of the first prong 111. The inlet end 246 is positioned in the gas manifold 120 between the gas inlet 121 and the first base 135. The outlet end 247 is positioned in the first fork 111 at or between the first base 135 and the first end 131.

In some constructions, the inlet end 246 of the flow directing element 240 is positioned in the gas delivery conduit 300 or in the gas inlet 121. In some constructions, the outlet end 247 of the flow directing element 240 is positioned in the gas manifold 120 and faces the first base 135 of the first fork 111.

The flow directing element 240 is positioned to provide a first fork gap 242 between itself and the inner wall of the first fork 111. Thus, the outer dimension of the portion (e.g., outlet end 247) of the flow directing element 240 positioned in the first prong 111 is smaller than the inner dimension of the first prong 111. The first fork gap 242 provides a first manifold guide stream 245. The first manifold guide flow 245 allows flow along the first fork 111, i.e. in the direction of the first end 131 to the first base 135, to be guided partially through the first fork gap 242. Thus, the patient expired gases entering the first prong 111 may be at least partially directed through the first prong gap 242 as the first manifold guide stream 245 and flow into the gas manifold 120 in the direction of the second prong 112.

The shape of the flow directing element 240 may be referred to as having angled protrusions.

The turbulent gas flow or flow that interacts with the patient's exhalation flow emerging from the outlet end 247 of the flow directing element 240 may also be the first manifold guide flow 245 prior to reaching the patient's nostrils.

The cross-sectional area of the first fork gap 242 is smaller than the cross-sectional area of the outlet end 247 of the flow directing element 240. However, in some constructions, the cross-sectional area of the first fork gap 242 is greater than the cross-sectional area of the outlet end 247 of the flow directing element 240.

In some constructions, the flow directing element 240 is positioned to provide a manifold gap 241 between itself and the inner wall of the gas manifold 120. The manifold gap 241 provides a second manifold guide stream 244. The second manifold guide stream 244 allows the flow of gas entering the gas manifold 120, i.e., from the gas delivery conduit 300, to be directed partially through the manifold gap 241. Thus, a portion of the gas flow entering the gas manifold 120 is directed as a second manifold guide stream 244 through the manifold gap 241 and into the gas manifold 120 in the direction of the second prong 112.

The cross-sectional area of the manifold gap 241 is smaller than the cross-sectional area of the inlet end 246 of the flow directing element 240. However, in some constructions, the cross-sectional area of the manifold gap 241 is greater than the cross-sectional area of the inlet end 246 of the flow directing element 240.

Thus, the flow directing element 240 directs all or a majority of the gas flow from the gas delivery conduit 300 into the first fork 111 as a first fork guide flow 243. The gas flow to the second fork 112 is a first manifold lead-through 245 through the first fork gap 242 and/or a second manifold lead-through 244 through the manifold gap 241.

The gas flow reaching the first fork 111 has less change of direction as it passes through the flow guiding element 240.

This arrangement results in a greater dynamic pressure at the first prong and a lesser dynamic pressure at the second prong 112. Thus, asymmetric flow is provided to the prongs 111, 112.

Referring to fig. 14, a patient interface 10 having a nasal interface 100 is shown. This arrangement is similar to the arrangement described with reference to fig. 1 and has a different configuration than the flow directing element 240 described with reference to fig. 13.

In this configuration, the flow directing element 240 provides an asymmetric gas flow to the first prong 111 and the second prong 112.

The flow guiding element 240 is formed at or near the gas inlet 121. The flow directing element 240 includes a first angled protrusion 248 to direct the flow of gas to the first prong 111. The first angled protrusion 248 is formed as a plate or wall. The gas flow from the gas inlet 121 enters the flow guiding element 240 and the first angled protrusion 248 directs the flow as a first fork guide flow 243 towards the first fork 111. Thus, the flow directing element 240 and the first angled protrusion 248 generally direct the flow of gas from the gas delivery conduit 300 to the first fork 111. The greater dynamic pressure at the first prong 111 compared to the second prong 112 creates an asymmetric flow.

A first angled protrusion 248 is located within the gas manifold 120 proximate to the gas inlet 121. Thus, the flow directing element 240 and the first angled protrusion 248 do not obstruct or (completely) restrict the flow in the manifold chamber 125, but instead rely on directing the flow to provide an asymmetric flow to one of the prongs 111, 112.

The flow provided to the second prong 112 by the first manifold guide flow 245 allows the exhalation from the patient to be directed back to the first prong 111 and may be directed by the opposite side of the first angled protrusion 248. In addition, some flow may not be directed entirely from the gas inlet 121 to the first prong 111, but rather into the manifold chamber 125 and to the second prong 112.

In some constructions, to assist in directing flow, the gas inlet 121 is positioned on a wall of the gas manifold 120 generally opposite the first prong 111 (or the second prong 112, as desired). Thus, the flow directing element 240 and the first angled protrusion 248 help direct flow to the associated prongs 111, 112 through the inlet of gas into the manifold chamber 125 itself. This may also be referred to as the forward access port 121.

In some constructions, the flow directing element includes a second angled projection 249. The second angled projections 249 help the first angled projections 248 to direct flow from the gas inlet 121. First angled projections 248 and second angled projections 249 are formed on opposite sides of gas inlet 121. The first angled protrusion 248 and the second angled protrusion 249 may be formed into a nozzle shape.

The flow directing element 240 may be positioned to direct flow to the second prong 112 instead of the first prong 111 to provide an asymmetric flow.

Referring to fig. 15, a patient interface 10 having a nasal interface 100 is shown. The arrangement is the same as that described with reference to fig. 14, including a flow directing element 240.

In this configuration, the nasal interface 100 also includes an additional flow directing element 250 or a second flow directing element 250.

The second flow directing element 250 is disposed at or near the inlet of the first fork 111, i.e., near the first base 135, within the manifold chamber 125.

In addition to the flow directing element 240, an additional flow directing element 250 directs the flow of gas from the gas delivery conduit 300 into the first fork 111. Thus, the first fork guide flow 243 through the manifold chamber 125 is further forced into the first fork 111 by the additional flow guide element 250. This ensures that a majority of the gas flow from the gas delivery conduit 300 is directed into the first prongs 111 and into the nostrils of the patient, thus providing an asymmetric flow compared to the second prongs 112.

The additional flow directing element 250 is formed as an angled plate or wall, optionally having a wedge shape, forming another nozzle shape at the inlet of the first fork 111 to direct flow therein. The gas flow from the gas inlet 121 enters the flow guiding element 240 and is guided as a first fork guiding flow 243 towards the first fork 111, and the additional flow guiding element 250 guides any flow that has been split into the first fork 111. The greater dynamic pressure at the first prong 111 compared to the second prong 112 creates an asymmetric flow.

Flow is provided to the second prong 112 by the first manifold guide stream 245 such that exhalation from the patient is directed back to the first prong 111. The additional flow directing element 250 forms a directing channel for the first manifold directing flow 245 into the manifold chamber 125. Thus, the exhaled flow is directed more into the manifold chamber 125, and thus toward the second fork 112. In addition, some of the gas flow may not be directed entirely into the first prong 111 from the gas inlet 121, but rather into the manifold chamber 125 and into the second prong 112. The additional flow directing element 250 also directs a portion of the flow as the second manifold directing flow 244.

Additional flow directing elements 250 may be positioned to direct flow to the second prong 112 instead of the first prong 111 to provide an asymmetric flow. This may be combined with the flow directing element 240 leading to the second fork 112.

The flow directing element 240 and the additional flow directing element 250 may be combined with other configurations discussed herein. For example, first fork element 201, second fork element 202, manifold element 203, first inlet element 209, and second inlet element 208 may be used to further restrict flow. Likewise, multiple gas delivery conduits 300 may also be used with one or more flow directing elements 240 and additional flow directing elements 250 as desired to create asymmetric flow at the tines 111, 112.

The flow directing elements 240, 250 as described herein may be formed as part of the gas inlet 121, the gas manifold 120, or the gas delivery conduit 300. That is, the flow directing elements 240, 250 may be formed as walls, parts or features of the gas inlet 121, the gas manifold 120 or the gas delivery conduit 300. Such a structure may be a separate structure that is later integrated with the gas inlet 121, the gas manifold 120, or the gas delivery conduit 300, or may be formed together (e.g., by an extrusion or molding process), or may be a portion of an overall structure (e.g., a nozzle shape for the gas inlet 121). The term "formed together" may also be considered to mean that the flow directing elements 240, 250 are not removable or permanently integral with the gas inlet 121, the gas manifold 120, or the gas delivery conduit 300.

Referring to fig. 16, a patient interface 10 having a nasal interface 100 is shown. This arrangement is the same as that described with reference to fig. 1, and as will be readily appreciated, can be optionally combined with any of the disclosures herein without any modification to the features described.

In this configuration, the first fork 111 and the second fork 112 are modified to have different lengths. Thus, a long first fork 111a is provided, wherein the distance between the first end 131 and the first base 135 is longer than the distance between the second end 132 and the second base 136 of the short second fork 112 a.

By providing a long first prong 111a and a short second prong 112a, the prongs 111a, 112a are modified (relative to each other) to have different internal flow resistances. Thus, when the gas flow has to travel further, the amount of flow through each fork 111a, 112a is different and the resulting flow is therefore asymmetric. One way is to have prongs of different lengths, noting that the flow resistance also depends on the length of the flow path.

In some constructions, the long first prong 111a is lengthened relative to the second prong 112 such that the short second prong 112a has the same length as the second prong 112 as described elsewhere in this document. Alternatively, the short second prongs 112a are shortened relative to the first prongs 111 such that the long first prongs 111a are the same length as the first prongs 111 as described elsewhere herein. However, in other arrangements, the length of both the first prong 111a and the second prong 112a changes. The change in relative length may be varied to provide the desired asymmetric flow.

The change in length of the prongs 111a, 112a may assume that the inner diameters are the same. In some constructions, the inner diameter may be different, which results in different prongs 111a, 112a requiring different lengths. In the infant interface 10, the effect of the length of the prongs is more pronounced when both the height and the inside diameter of the prongs are small. Thus, a small difference in fork length will have a relatively large impact on flow resistance and thus asymmetric flow.

In some constructions, the second prong 112 is relatively longer than the first prong 111. Variations in prong lengths 111a, 112a may be combined with any of the disclosure herein, for example, first prong element 201, second prong element 202, manifold element 203, first inlet element 209, and second inlet element 208 may be used to further restrict flow.

The prongs of varying length, such as the long first prong 111a and the short second prong 112a or any variation in length of prongs 111, 112, may be combined with any of the configurations described herein, such as with other features providing asymmetric flow in a non-limiting example.

Referring to fig. 17, a patient interface 10 having a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to fig. 1 and may be combined with any of the disclosures herein. As will be readily appreciated, optional combinations with any of the disclosures herein will not require any modification of the features described.

In this configuration, the first fork 111 and the second fork 112 are modified to have different end geometries. Thus, a nozzle-type first fork 111b is provided, wherein the first end 131 tapers or narrows at its top end to form a nozzle. The diffuser-type second prong 112b is disposed at a location where the second end 132 expands at its top end to form a diffuser.

In some constructions, one of the nozzle-style first prongs 111b or the diffuser-style second prongs 112b are provided.

By providing the nozzle-like first prongs 111b and the diffuser-like second prongs 112b, the prongs 111b, 112b are modified (relative to each other) to have different internal flow resistances. Thus, the amount of flow through each prong 111b, 112b is different, as the gas flow has a different outlet profile defined by the ends 131, 132.

The nozzle-like first prong 111b behaves like a nozzle, resulting in a flow exiting the nozzle-like first prong 111b with a higher velocity and narrow profile than the unmodified prongs 111, 112. Thus, a higher gas velocity at one fork will result in an asymmetric flow.

The diverging second prongs 112b behave like a diffuser such that the flow directed out of the diverging second prongs 112b has a wider profile and a lower exit velocity. Thus, a lower gas velocity at one fork will result in an asymmetric flow.

While the effect of the diffuser is to result in a lower exit velocity, in some configurations, a further effect of using the diffuser-type second prongs 112b is that the diffuser ends may occlude the patient's nostrils in which the ends extend to fill the nostrils. This may lead to an increase in flow resistance. However, this has the advantage of producing a different gas flow compared to the unmodified prongs 111, 112. Thus, an asymmetric flow is formed at the fork.

Another advantage of the diffuser-type second prongs 112b is that noise may be attenuated compared to unmodified prongs 111, 112 or nozzle-type first prongs 111 b. The same gas flow exiting through the larger opening has a lower velocity and therefore less sound.

In some configurations, the nozzle may be disposed at the second prong 112 and/or the diffuser may be disposed at the first prong 111. The nozzle-style first prongs 111b and the diffuser-style second prongs 112b described herein may be combined with any other configuration described herein, and optionally also with prongs of different lengths as described with reference to fig. 16.

Referring to fig. 18, a patient interface 10 having a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to fig. 1 and may be combined with any of the disclosures herein. It will be appreciated that other features need not be modified to combine with the embodiments described herein.

In this configuration, the first fork 111 is modified to have an internal ridge. Thus, a ridged first prong 111c is provided, wherein the ridge 260 is formed on the inner surface of the ridged first prong 111 c.

By the ridged first prong 111c and the unmodified second prong 112, the prongs 111c, 112 have different internal flow resistances (relative to each other) due to the different inner surface areas. Thus, the amount of flow through each prong 111c, 112 is different because the gas flow varies, is blocked or disturbed in the ridged first prong 111c, and the resulting flow is asymmetric.

To increase the surface area, the ridges 260 are formed either as grooves in the inner surface of the ridged first prong 111c or as protrusions on the inner surface of the ridged first prong 111 c. In some constructions, the ridge 260 is formed by adding material from the ridged first prong 111c, and in other constructions, the ridge 260 is formed by removing material from the ridged first prong 111 c.

The ridges 260 may be formed as rings, spirals, or bands in a substantially concentric pattern on the interior of the ridged first fork 111 c. Any number of ridges 260 may be formed, such as a single ridge 260 or a plurality of ridges 260. The ridges 260 may be equally spaced or have varying spacing. The dimensions (e.g., protruding dimensions) of the ridges 260 may be the same for all ridges 260, or may be varied.

In some constructions, the ridge 260 can be formed in the second prong 112. When formed in the second prong 112, either no ridge 260 is present in the first prong 111, or the ridged first prong 111c has a different ridge 260 to create a different internal flow resistance to provide an asymmetric flow at the prongs.

The ridged first prong 111c may be combined with other configurations described herein, and may also optionally be combined with configurations such as the different length prongs described with reference to fig. 16 and/or the nozzle first prong 111 b/diffuser second prong 112b described with reference to fig. 17.

Referring to fig. 19, a patient interface 10 having a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to fig. 1 and may be combined with any of the disclosures herein. It will be appreciated that other features need not be modified to combine with the embodiments described herein.

In this configuration, the first fork 111 is modified to have an internal fin 261. Thus, a finned first fork 111d is provided, wherein fins 261 are formed on the inner surface of the finned first fork 111 d.

The combination of the finned first prong 111d and the unmodified second prong 112, the prongs 111d, 112 have different internal flow resistances (relative to each other) due to the different inner surface areas. Thus, the amount of flow through each prong 111d, 112 is different because the gas flow varies, is blocked or disturbed in the finned first prong 111d, and the resulting flow is asymmetric.

To increase the surface area, the fins 261 are either formed as grooves in the inner surface of the finned first fork 111d or as protrusions on the inner surface of the finned first fork 111 d. In some constructions, the fin 261 is formed by adding material from the finned first fork 111d, and in other constructions, the fin 261 is formed by removing material from the finned first fork 111 d.

The fins 261 may be formed as lines, bands or strips in a generally axial direction pattern inside the finned first fork 111 d. Any number of fins 261 may be formed, such as one fin 261 or a plurality of fins 261. The fins 261 may be equally spaced or have varying spacing. The dimensions (e.g., protruding dimensions) of the fins 261 may be the same for all fins 261 or may be varied.

In some constructions, the fin 261 can be formed in the second prong 112. When formed in the second prong 112, the fins 261 are either absent from the first prong 111 or the finned first prong 111d has differently configured fins 261, e.g., different sizes, arrangements, or numbers, to create different internal flow resistances to provide asymmetric flow at the prongs.

The features of the ridges 260 or fins 261 described with reference to fig. 18 and 19 may be collectively referred to as surface features.

The finned first prongs 111d may be combined with other configurations described herein, and optionally may also be combined with configurations such as prongs of different lengths as described with reference to fig. 16, nozzle-type first prongs 111 b/diffuser-type second prongs 112b as described with reference to fig. 17, or ridges 260 in either the first prongs 111 or second prongs 112 as described with reference to fig. 18.

Referring to fig. 20, a patient interface 10 having a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to fig. 1 and may be combined with any of the disclosures herein. As will be readily appreciated, optional combinations with any of the disclosures herein will not require any modification of the features described.

In the present configuration, the first fork 111 is modified to have a non-circular cross-section or a non-circular cross-sectional shape. Thus, a non-circular first prong 111e is provided, wherein the shape of the lumen of the non-circular first prong 111e is different from a cylindrical or substantially cylindrical shape (which is the general shape of a catheter).

The combination of the non-circular first prong 111e and the unmodified second prong 112 results in the prongs 111e, 112 having different internal flow resistances (relative to each other) due to the different inner surface areas. Thus, the amount of flow through each prong 111e, 112 is different compared to the substantially circular cross-section of the second prong 112, because the gas flow is altered, blocked or disturbed in the non-circular first prong 111e, and the resulting flow is asymmetric.

The contour of the non-circular first fork 111e may take various forms in order to increase or change the surface area. In a non-limiting example, the first profile 111f has a circular profile when viewed in the axial direction, with an additional smaller diameter circular profile formed on its wall. Thus, the flow area of the first profile is reduced by the size of the smaller diameter circle. In another non-limiting example, the second profile 111g has a circular profile when viewed in the axial direction, with an additional smaller equivalent diameter U-shaped profile formed on the wall therein. The curved portion of the U-shape protrudes to the center of the circular profile. Thus, the flow area of the first profile is reduced by the U-shaped sized profile. In another non-limiting example, the third profile 111h has a triangular profile with curved corners when viewed in the axial direction. Thus, the flow area of the first profile varies depending on the size of the third profile 111h, or the shape of the channel formed by the third profile 111h itself results in a flow characteristic that is different from a circular profile. In some constructions, any profile other than a circular cross-section may be used.

The non-circular first prong 111e may be formed along the length of the prong, or may be formed partially along the prong, such as at one or between the first end 131 and the first base 135. The size and variation of the profile shape may vary along the length of the fork.

In some constructions, a non-circular profile (e.g., first profile 111f, second profile 111g, or third profile 111 h) can be formed in second prong 112. When formed in the second prong 112, the non-circular first prong 111e may be replaced with an unmodified first prong 111, or the non-circular first prong 111e may have a cross-sectional profile that is different from the cross-sectional profile of the second prong 112. Resulting in different internal flow resistances to provide asymmetric flow at the fork.

The first contour 111f, the second contour 111g, and the third contour 111h may be oriented in any direction as the prongs 111, 112. Thus, any feature (e.g., the protruding U-shape of the first profile 111f or the second profile 111g or the triangular flat face of the third profile 111 h) may face inward toward the patient's face, face outward away from the patient's face, or laterally across the patient's face-or any other orientation.

In some constructions, the protruding portion of the fork profile (e.g., the U-shape of the first profile 111f or the second profile 111 g) is used to accommodate an auxiliary tube, such as a nasogastric tube. Such auxiliary tubes may be positioned inside or outside the prongs 111, 112.

In some constructions, the varying profile of the tines 111, 112, such as described with reference to fig. 20, or any other variation in profile, may exist only at the ends 131, 132 of the tines 111, 112. Such a profile may include gaps or protrusions to accommodate auxiliary tubes as described elsewhere. Such auxiliary tubes may be provided on the outside or inside of the prongs 111, 112. The auxiliary tube itself may block the nostrils, increasing the flow resistance, providing an asymmetric flow at the (at least one) prongs 111, 112.

The non-circular first prong 111e may be combined with any other configuration described herein, and optionally with configurations such as prongs of different lengths as described with reference to fig. 16, nozzle first prong 111 b/diffuser second prong 112b as described with reference to fig. 17, ridges 260 in at least one of the first prong 111 or second prong 112 as described with reference to fig. 19, and/or fins 261 formed in at least one of the first prong 111 or second prong 112 as described with reference to fig. 20.

In some constructions, further modifications may be made to the first prong 111 or the second prong 112 to modify the surface area or flow therethrough, such as described with reference to fig. 2, 11, or 16-20, which modifications may be provided as an alternative or in addition to those embodiments described herein. In one configuration, at least one of the first prong 111 or the second prong 112 has an increased wall thickness relative to the other. The increased wall thickness results in at least one of the first prong 111 or the second prong 112 having a reduced cross-sectional flow area and, therefore, less gas flow may pass therethrough. This results in an asymmetric flow due to the difference in internal flow resistance of the prongs 111, 112.

In another configuration, at least one of the first prong 111 or the second prong 112 has a limiter at the ends 131, 132 of the prongs 111, 112. The limiter is an alternative or in addition to the first fork element 201 or the second fork element 202. For example, in some constructions, the limiter is formed as part of the ends 131, 132 of the prongs 111, 112 themselves, such as having a partial closure formed thereon.

In another configuration, at least one of the first fork 111 or the second fork 112 has a base limiter 262 at the first base 135 or the second base 136 of the fork 111, 112. The limiter is an alternative or in addition to the first fork element 201 or the second fork element 202. An exemplary configuration of the base end limiter 262 is provided in fig. 21. In fig. 21, a base end limiter 262 is shown formed at the second base 136 of the second fork 112. The base end restriction 262 is formed with a flow disruption inlet to the second prong 112, such as with a flat flow facing surface, with a sharp edge opening up into the flow channel of the second prong 112. This arrangement provides flow disruption to reduce the flow of gas through the base end restriction 262 relative to the first fork 111 without any base end restriction 262. Thus, an asymmetric flow is provided at the fork.

The base end restriction 262 has a flow directing surface for reversing flow through the second prong 112. Thus, exhaled gas is not restricted in the same manner by the base end restriction 262 to ensure that there is no pressure build-up at the patient's nostrils.

In some constructions, the base end limiter 262 may be formed in the first fork 111. When formed in the first prong 111, the second prong 112 may be an unmodified second prong 112, or may have a base end limiter 262 that provides different flow characteristics. Although examples of the base end limiter 262 are provided, other variations are possible.

Referring to fig. 22, a patient interface 10 having a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to fig. 1 and may be combined with any of the disclosures herein. As will be readily appreciated, optional combinations with any of the disclosures herein will not require any modification of the features described.

In this configuration, the first fork 111 is modified to have a valve. Thus, a valved first prong 111i is provided wherein the duckbill valve 263 is formed within the valved first prong 111 i.

The duckbill valve 263 is positioned in a direction in the valved first prong 111i to allow gas flow from the manifold chamber 125 through the valved first prong 111i to the patient's nostrils in varying amounts based on the pressure differential of the duckbill valve 263. In some constructions, the duckbill valve 263 may only allow flow to pass above a defined pressure, after which the gas flow increases based on the pressure differential. To function in this manner, the duckbill valve 263 is in the closed position 265 until a defined pressure is achieved at which the duckbill valve 263 begins to open to allow flow. The amount/flow rate causes a pressure differential that further opens the duckbill valve 263 until the duckbill valve reaches the fully open position 264. Alternatively, the duckbill valve 263 only allows flow through at low pressure differentials, and the flow varies as a function of the pressure differential, with the flow increasing as the pressure differential increases. Duckbill valve 263 acts as a one-way valve preventing back flow of the gas flow from the patient. Thus, the greater pressure differential between the first end 131 of the valved first prong 111i and the first base 135 of the valved first prong 111i forces the duckbill valve 263 to the closed position 265. In this regard, the valved first prongs 111i are non-sealing prongs to ensure that there is no pressure build-up in the patient's nostrils. The pressure requirements allowed to flow through the valved first prong 111i and the duckbill valve 263 result in an asymmetric flow relative to the unmodified second prong 112.

In some constructions, the duckbill valve 263 can be formed in the second fork 112. When formed in the second prong 112, the first prong 111 may be an unmodified first prong 111, or may have a duckbill valve 263 configured to result in different flow characteristics. Although examples of duckbill valve 263 are provided, other valves may be used.

Duckbill valve 263 can be combined with any other configuration described herein.

In some constructions, at least one of the first prong 111 or the second prong 112 is angled with respect to a midline plane of the nasal interface 100, optionally with respect to the patient's nasal septum in use. Thus, the axis of the first prong 111 can be at a different relative angle to the axis of the second prong 112 (with reference to the midline plane of the nasal interface 100). For example, one prong 111, 112 may be unmodified, while the other prong 111, 112 is angled "outwardly", e.g., toward the proximal wall of the gas manifold 120 (or away from the opposing prong 111, 112), such that the prongs 111, 112 abut the nasal wall. The gas flow exiting the angled prongs 111, 112 may encounter resistance from the nasal wall and create different pressures at the distal end 131, 132 of each prong, thereby causing asymmetric flow.

In some constructions, at least one of the first prong 111 or the second prong 112 is angled "inwardly" toward the opposing prong 111, 112, for example. This may result in less restriction depending on the degree of angle.

Referring to fig. 23, a patient interface 10 having a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to fig. 1 and may be combined with any of the disclosures herein. As will be readily appreciated, optional combinations with any of the disclosures herein will not require any modification of the features described.

In this configuration, the nasal interface 100 includes first 111 and second 112 nasal prongs and a third 115 nasal prong. The third nasal prongs 115 are formed in the same manner as the first nasal prongs 111 or the second nasal prongs 112, with flow passages allowing gas to flow therethrough.

In addition to the first and second prongs 111, 112, the third prong is also in fluid communication with the gas inlet 121 through the manifold 120. The gas inlet 121 is positioned at the manifold 120 such that the first prong 111 is closer to the gas inlet 121, the third prong 115 is further from the gas inlet 121, and the second prong 112 is positioned between the first prong and the second prong.

The first, second and third prongs 111, 112, 115 are spaced apart so as to be engageable into the nostrils of the patient as adjacent pairs of prongs. Thus, the first prong 111 and the second prong 112 may engage the nostril of the patient as described with respect to the two prong 111, 112 configuration described elsewhere in this disclosure, or the second prong 112 and the third prong 115 may engage the nostril of the patient.

Thus, the nasal interface 100 of this construction has a first prong 111 or a third prong 115 that does not engage and open to the atmosphere when in use. To avoid pressure losses and gas flow within the gas manifold through the unengaged prongs 111, 115, the closure 119 is releasably engaged within the unused prongs 111, 115. Thus, the nasal interface 100 may be reconfigured by moving the closure 119 between a first configuration in which the first prong 111 and the second prong 112 allow the passage of gas to the nostril of the patient, and a second configuration in which the second prong 112 and the third prong 115 allow the passage of gas to the nostril of the patient. The closure 119 is engaged to prevent the flow of gas from passing through the third prong 115 or the first prong 111 between the first configuration and the second configuration, respectively.

Closure 119 may be in any suitable form, such as a plug or cap. Furthermore, in some constructions, the closure 119 may be engaged by other portions of the nasal interface 100. For example, the inlet 121 or gas delivery conduit 300 may be inserted into the gas manifold 120 to block at least one of the prongs 111, 112, 115. Thus, flow is provided to the unblocked prongs 111, 112, 115. In this configuration, a closure 119 is formed at the base of the prongs 111, 112, 115. The closure 119 may be movable by inserting, for example, the gas delivery conduit 300 into an opposite side of the gas manifold 120 (e.g., where the second inlet 122 is present). Thus, the prongs near the respective inlets 121, 122 are blocked by the gas delivery conduit 300. Alternatively, the closure 119 is formed by the distance the gas delivery conduit 300 is inserted into the gas manifold 120, such as by having openings in the conduit that align with the fork openings or openings in the gas manifold 120 at different locations. Other portions of the nasal interface 10 may be reconfigurable to enclose at least one prong 111, 112, 115 as described herein.

The first prong 111, the second prong 112, and the third prong 115 are configured to have different gas flows therethrough to create an asymmetric flow as described throughout this document. Thus, as a non-limiting example, at least one of the first fork 111, the second fork 112, or the third fork 115 has a flow restriction in the form of a first fork element 201, a second fork element 202, a manifold element 203, a first inlet element 209 and a second inlet element 208, a flow directing element 240, additional flow directing elements 250, different length forks as described with reference to fig. 16, nozzles and diffusers as described with reference to fig. 17, ridges 260 as described with reference to fig. 19, fins 261 as described with reference to fig. 20, base end restrictions 262 as described with reference to fig. 21, or duckbill valves 263 as described with reference to fig. 22. Further, in some configurations, second inlet 122, as described with reference to fig. 9, is combined with first prong 111, second prong 112, and third prong 115 to allow gas to flow on either side of gas manifold 120. This provides additional control for asymmetric flow.

The flow restrictions of at least one of the first prong 111, the second prong 112, and the third prong 115 allow a user to move their nostrils between engagement with one of the first prong 111 and the second prong 112 to engagement with the second prong 112 and the third prong 115, thereby having asymmetric flows of different configurations.

In some configurations, the first prong 111 and the third prong 115 are configured to have the same gas flow therethrough, while the second prong 112 is configured to have different gas flows therethrough to allow for switching of asymmetric flows between the left naris and the right naris. Thus, a greater dynamic pressure is provided at the second prong 112 and a lesser dynamic pressure is provided at the first prong 111 and the third prong 115, or a greater dynamic pressure is provided at the first prong 111 and the third prong 115 and a lesser dynamic pressure is provided at the second prong 112.

In an alternative configuration, the first fork 111 and the second fork 112 are modular to allow for fork-type removal and replacement with different flow restrictions.

As described above, the patient interface 10 with the nasal interface 100 constructed as described herein may be used in methods of delivering gas to the 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 the respiratory condition of a patient in need thereof.

The patient interface 10 including a nasal interface 100 of the type disclosed herein may be used in a respiratory therapy system for delivering gas to a patient.

In some constructions, the respiratory therapy system 1000 includes a respiratory therapy device 1100 and a patient interface 10, including a nasal interface 100.

An exemplary respiratory therapy apparatus 1100 is shown in fig. 24.

Respiratory therapy apparatus 1100 includes a main housing 1101 that houses a flow 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, a 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 (gas flow) 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, a "gas flow" may refer to any gas flow that may be used in a respiratory assist or breathing apparatus, such as an ambient air flow, a flow comprising substantially 100% oxygen, a flow comprising some combination of ambient air and oxygen, and/or the like.

The patient respiratory conduit 300 is coupled at one end to a gas flow outlet 1021 in a housing 1100 of the respiratory therapy apparatus 1100. The patient breathing conduit 300 is connected at the other end to the nasal interface 100 by a gas manifold 120 and nasal prongs 111, 112.

The flow of gas produced by respiratory therapy device 1100 may be humidified and delivered to the patient through nasal interface 100 via patient conduit 300. The patient conduit 300 may have a heater to heat the flow of gas through to the patient. For example, the patient catheter 300 may have a heating wire 300a to heat the flow of gas through to the patient. The heating wire 300a may be under the control of the controller 1013. The patient catheter 300 and/or nasal interface 100 may be considered part of the respiratory therapy device 1100 or alternatively may be considered a peripheral device thereof. The respiratory therapy apparatus 1100, the respiratory conduit 300, and the patient interface 10 including the nasal interface 100 together may form a respiratory therapy system 1000.

The controller 1013 may control the flow generator 1011 to produce a gas flow 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 so forth. The flow of gas is directed to the patient through the patient catheter 300 and the nasal interface 100. The controller 1013 may also control the heating elements in the humidifier 1012 and/or the heating element 300a in the gas delivery conduit 300 to heat the gas to a desired temperature for a desired therapeutic level and/or comfort level of the patient. The controller 1013 may be programmed with or may determine an appropriate target temperature for the gas flow. In some configurations, a gas mixture composition including supplemental oxygen and/or therapeutic drug administration may be provided through a supplemental oxygen inlet. The gas mixture composition 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.

Oxygen inlet port 1028 may include a valve 1028a through which pressurized gas may enter a flow generator or blower. The valve may control the flow of oxygen into the flow generator blower. The valve may be any type of valve including a proportional valve or a binary valve. The oxygen source may be an oxygen tank or a hospital oxygen supply. The purity of medical grade oxygen is typically between 95% and 100%. A lower purity oxygen source may also be used. Examples of valve modules and filters are disclosed in PCT publication No. WO2018/074935 and U.S. patent application publication No. 2019/0255276, both entitled "valve module and filter". The contents of these specifications are incorporated herein by reference in their entirety.

The respiratory therapy apparatus 1100 may measure and control the oxygen content of the gas delivered to the patient and, thus, the oxygen content of the gas inhaled by the patient. During high flow therapy, the delivered high flow rate gas may meet or exceed the peak inspiratory flow of the patient. This means that the volume of gas delivered by the device to the patient during inhalation meets or exceeds the volume of gas inhaled by the patient during inhalation. Thus, high flow therapy helps to prevent entrainment of ambient air as the patient inhales, as well as exhaled gases that flush the patient's airway. Entrainment of ambient air may be prevented if the flow rate of the delivered gas reaches or exceeds the peak inspiratory flow of the patient, and the gas delivered by the device is substantially the same as the gas inhaled by the patient. Thus, the oxygen concentration measured in the device, the fraction of oxygen delivered (FdO 2) will be substantially the same as the oxygen concentration breathed by the user, the fraction of inhaled oxygen (FiO 2), and as such these terms may be considered equivalent.

The operational sensors 1003a, 1003b, 1003c (e.g., flow, temperature, humidity, and/or pressure sensors) may be placed at various locations in the respiratory therapy device 1100. Additional sensors (e.g., sensors 1020, 1025) may be placed at various locations on the patient catheter 300 and/or 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 constructions, providing a suitable treatment includes satisfying a peak inspiratory flow of the patient. 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 treatment device 1100, including but not limited to the flow generator 1011, humidifier 1012, and heater wire 300a, or accessories or peripherals associated with the respiratory treatment 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.

Oxygen may be measured by placing one or more gas constituent sensors (e.g., ultrasonic transducer systems, also referred to as ultrasonic sensor systems) after the oxygen and ambient air have been mixed. The measurements may be made within the device, the delivery catheter, the patient interface, or at any other suitable location.

Respiratory therapy device 1100 may include a patient sensor 1026, such as a pulse oximeter or a patient monitoring system, to measure one or more physiological parameters of the patient, such as blood oxygen saturation (SpO 2), heart rate, respiration rate, perfusion index of the patient, and to provide a measurement of signal quality.

Patient sensor 1026 may communicate with controller 1013 via a wired connection or via communication via a wireless transmitter on patient sensor 1026.

Patient sensor 1026 may be a disposable adhesive sensor designed to be attached to a patient's finger. Patient sensor 1026 may be a non-disposable sensor.

Sensors designed for different age groups and connected to different locations on the patient are available, which can be used with respiratory therapy apparatus 1100.

Pulse oximeters are typically attached to a user at the user's finger, although other locations, such as the earlobe, are also optional. The pulse oximeter will be connected to a processor in the device and will continuously provide signals indicative of the patient's blood oxygen saturation. Patient sensor 1026 may be a heat exchangeable device that may be attached or exchanged during operation of respiratory therapy device 1100. For example, patient sensor 1026 may use a USB interface or use a wireless communication protocol (e.g., such as near field communication, wiFi, or wireless communication protocol) Is connected to a respiratory therapy device 1100. When patient sensor 1026 is turned off during operation, respiratory therapy device 1100 may continue to operate in its previous operating state for a defined period of time. After a defined period of time, the respiratory therapy device 1100 may trigger an alarm, transition from an automatic mode to a manual mode, and/or exit the control mode entirely (e.g., automatic mode or manual mode). Patient sensor 1026 may be a bedside or other patient monitoring system that communicates with respiratory therapy device 1100 via a physical or wireless interface.

Respiratory therapy device 1100 may include a high flow therapy device. High flow therapy as discussed herein is intended to be given its typical ordinary meaning as understood by those skilled in the art, which generally refers to a respiratory assistance system that delivers a target flow of humidified breathing gas via an intentionally unsealed patient interface at a flow rate that is generally intended to meet or exceed the patient's inspiratory flow. Typical patient interfaces include, but are not limited to, nasal or tracheal patient interfaces. Typical flow rates for adults typically range from about fifteen liters per minute (lpm) to about seventy liters per minute or greater, but are not so limited. Typical flow rates for pediatric patients (e.g., newborns, infants, and children) generally range from about one liter per kilogram of patient body weight per minute to about three liters per kilogram of patient body weight per minute or greater, but are not so limited. High flow therapy may also optionally include a gas mixture composition that includes supplemental oxygen and/or administration of a therapeutic agent. High flow therapy is commonly referred to as Nasal High Flow (NHF), humidified High Flow Nasal Cannula (HHFNC), high Flow Nasal Oxygen (HFNO), high Flow Therapy (HFT) or Tracheal High Flow (THF), among other common names. The flow rate used to achieve the "high flow rate" may be any of the flow rates listed below. For example, in some configurations, for an adult patient, "high flow therapy" may refer to delivering a gas to the patient at a flow rate of greater than or equal to about 10 liters per minute (10 lpm), such as between about 10lpm and about 100lpm, or between about 15lpm and about 95lpm, or between about 20lpm and about 90lpm, or between 25lpm and 75lpm, or between about 25lpm and about 85lpm, or between about 30lpm and about 80lpm, or between about 35lpm and about 75lpm, or between about 40lpm and about 70lpm, or between about 45lpm and about 65lpm, or between about 50lpm and about 60 lpm. In some configurations, for neonatal, infant, or pediatric patients, "high flow therapy" may refer to delivering a gas to the patient at a flow rate greater than 1lpm, for example between about 1lpm and about 25lpm, or between about 2lpm and about 25lpm, between about 2lpm and about 5lpm, or between about 5lpm and about 25lpm, or between about 5lpm and about 10lpm, or between about 10lpm and about 25lpm, or between about 10lpm and about 20lpm, or between about 10lpm and 15lpm, or between about 20lpm and 25 lpm. High flow therapy devices for adult patients, neonatal, infant or pediatric patients may deliver gas to the patient at a flow rate between about 1lpm and about 100lpm or at a flow rate within any of the sub-ranges described above. The flow therapy device 1000 may deliver any concentration of oxygen (e.g., fdO 2) up to 100% at any flow rate between about 1lpm and about 100 lpm. In some constructions, any flow rate may be combined with an oxygen concentration (FdO 2) of about 20% -30%, 21% -40%, 30% -40%, 40% -50%, 50% -60%, 60% -70%, 70% -80%, 80% -90%, and 90% -100%. In some combinations, the flow rate may be between about 25lpm and 75lpm, combining about 20% -30%, 21% -40%, 30% -40%, 40% -50%, 50% -60%, 60% -70%, 70% -80%, 80% -90%, and 90% -100% oxygen concentration (FdO 2). In some constructions, the respiratory therapy apparatus 1100 may include a safety threshold that prevents a user from delivering a large amount of oxygen to the patient when operating in manual mode.

In some constructions, the respiratory therapy apparatus 1100 includes a controller 1013; blood oxygen saturation sensor 1026; an ambient air inlet 1027; an oxygen inlet 1028; a valve 1028a in fluid communication with oxygen inlet 1028 to control the flow of oxygen through oxygen inlet 1028; and a gas outlet 1021; wherein the controller 1013 is configured to control the valve 1028a based on at least one measurement of oxygen saturation from the blood oxygen saturation sensor 1026.

A patient interface 10 for use in a respiratory therapy system 1000 having a respiratory therapy apparatus 1100 includes a nasal interface 100 comprising: a first fork 111 and a second fork 112 that are asymmetric to each other; and a gas manifold 120 comprising a gas inlet 121, wherein the first prong 111 and the second prong 112 are in fluid communication with the gas inlet 121. The nasal interface 100 is configured to induce asymmetric gas flow at the nostrils of the patient.

The first and second prongs 111 and 112 are asymmetric with each other or with each other, or are different in shape and configuration from each other, or are asymmetric when compared to each other.

In some constructions, the nasal interface 100 includes an interface body 118 that includes a first prong 111 and a second prong 112.

In some constructions, the gas manifold 120 is integral with the interface body 118 or separate from and coupleable with the interface body 118.

In some constructions, the first prong 111 and the second prong 112 are configured to engage the nasal passages in a non-sealing manner.

In some constructions, the first prong 111 and the second prong 112 allow exhaled air to escape around the first prong and the second prong.

In some configurations, the first prong 111 and the second prong 112 are configured to provide gas to the patient without interfering with spontaneous breathing of the patient.

The nasal interface 100 may have any one or more of the features and/or functions described herein with respect to the nasal interface 100.

In some constructions, the respiratory therapy apparatus 1000 includes a flow generator 1011 and a humidifier 1012.

In some constructions, the respiratory therapy system includes a patient catheter 300 having a heater 300 a.

In some constructions, the patient interface includes a gas permeable tube (breathable tube) in fluid communication with the gas inlet 121, and the patient interface further includes a headgear to retain the nasal interface on the patient's face.

Patients with various health conditions and diseases may benefit from oxygen therapy. For example, patients with Chronic Obstructive Pulmonary Disease (COPD), pneumonia, asthma, bronchopulmonary dysplasia, heart failure, cystic fibrosis, sleep apnea, lung disease, respiratory trauma, acute respiratory distress, pre-and post-operative oxygen delivery, and other conditions or diseases may benefit from oxygen therapy. A common approach to treat these problems is to prevent their blood oxygen saturation (SpO 2) from dropping too low (e.g., below about 90%) by providing supplemental oxygen to the patient. However, supplying too much oxygen to the patient would over oxidize their blood and is also considered dangerous. Typically, the SpO2 of the patient is maintained in the range of about 80% to about 99%, preferably about 92% to about 96%, although these ranges may vary depending on the condition of the patient. Because of various factors, such as respiratory rate, lung tidal volume, heart rate, activity level, height, weight, age, gender, and other factors, none of the prescribed supplemental oxygen levels can consistently achieve SpO2 responses within a target range for each patient. Each patient will periodically require that the oxygen portion (FdO 2) they are delivering to the patient be monitored and regulated to ensure that they receive the correct FdO2 to achieve the target SpO2. Obtaining proper and consistent SpO2 is an important factor in treating patients with various health conditions or diseases. In addition, patients suffering from these health problems may benefit from a system that automatically controls oxygen saturation. The present disclosure is applicable to a wide range of patients requiring rapid and accurate oxygen saturation control.

Referring to fig. 24, the controller 1013 may be programmed or configured to perform a closed loop control system for controlling the operation of the respiratory therapy apparatus 1100. The closed loop control system may be configured to ensure that the patient's SpO2 reaches a target level and remains at or near that level at all times.

The controller 1013 may receive input from a user, which may be used by the controller 1013 to implement a closed loop control system. The target SpO2 value may be a single value or a range of values. The value may be preset, selected by a clinician, or determined based on the type of patient, where the type of patient may refer to the current affliction, and/or information about the patient, such as age, weight, height, gender, and other patient characteristics. Similarly, the target SpO2 may be two values, each value selected in any of the manners described above. These two values represent a range of acceptable values for SpO2 for the patient. The controller may target values within the range. The target value may be the middle value of the range, or any other value within the range, which may be preset or selected by the user. Or the range may be automatically set based on the target value of SpO 2. The controller may be configured to have one or more set responses when the SpO2 value of the patient moves outside of the range. The response may include an alarm, manual control to change to FdO, changing FdO2 to a particular value, and/or other responses. The controller may have one or more ranges, wherein one or more different responses occur when moving outside of each range.

Typically, spO2 will be controlled between about 80% and about 100%, or between about 80% and about 90%, or between about 88% and about 92%, or between about 90% and about 99%, or between about 92% and about 96%. SpO2 may be controlled between any two suitable values selected from any two of the ranges described above. The target SpO2 may be between about 80% and about 100%, or between about 80% and about 90%, or between about 88% and about 92%, or between about 90% and about 99%, or between about 92% and about 96%, or about 94%, or about 90%, or about 85%, or 85%. The SpO2 target may be any value between any two suitable values selected from any two of the ranges described above. The SpO2 target may correspond to a median value of the limited range of SpO 2.

FdO2 may be configured to control over a range. If the flow rate reaches or exceeds the peak inspiratory flow of the patient, the oxygen concentration measured in the device (FdO 2) may be substantially the same as the oxygen concentration (FiO 2) breathed by the patient, and thus these terms may be considered equivalent. Each limit of the range may be preset, selected by a user, or determined based on the type of patient, where the type of patient may refer to the current affliction, and/or information about the patient, such as age, weight, height, gender, and/or other patient characteristics. Alternatively, a single value of FdO2 may be selected, and the range may be determined based at least in part on that value. For example, the range may be a set amount above and below the selected FdO < 2 >. The FdO selected may be used as a starting point for the controller. If the controller attempts to move FdO out of range, the system may have one or more responses. These responses may include alarms, preventing FdO from moving out of range, manual control to switch to FdO2, and/or switching to a particular FdO2. The device may have one or more ranges, wherein one or more different responses occur when it reaches a limit value for each range.

Referring to fig. 25, a schematic diagram of a closed loop control system 1500 is shown. A closed loop control system may utilize two control loops. The first control loop may be implemented by an SpO2 controller. The SpO2 controller may determine the target FdO2 based in part on the target SpO2 and/or the measured SpO 2. As described above, the target SpO2 value may be a single value or a range of acceptable values. The value may be preset, selected by a clinician, or automatically determined based on the characteristics of the customer. Typically, the target SpO2 value is received or determined prior to or at the beginning of the treatment period, although the target SpO2 value may be received at any time during the treatment period. During the treatment period, the SpO2 controller may also receive as inputs: measured FdO readings from the gas composition sensor, as well as measured FdO readings and signal quality readings from the patient sensor. In some configurations, the SpO2 controller may receive the target FdO2 as an input, in which case the output of the SpO2 controller may be provided directly back to the SpO2 controller as an input. Based at least in part on this input, the SpO2 controller may output the target FdO2 to the second control loop.

During the treatment period, the SpO2 and FdO controller may continue to automatically control operation of the respiratory treatment apparatus 1100 until the treatment period ends or an event triggers a change from an automatic mode to a manual mode.

The increased irrigation caused by the asymmetry of prongs 111, 112 in nasal interface 100 may increase the effectiveness of oxygen replenishment. Closed loop SpO2 control with an asymmetric nasal interface 100 may allow the patient's SpO2 to remain at or near a target value, reducing the amount of oxygen used when compared to symmetric nasal high flow. This may result in an oxygen saving.

The respiratory therapy system may have any one or more of the features and functions described in PCT publication No. WO2021/049954 and U.S. provisional application No. 62/898,464. The contents of these specifications are incorporated herein by reference in their entirety.

Fig. 26 illustrates an alternative exemplary respiratory therapy system 2000 that may utilize patient interface 10, including nasal interface 100.

In the illustrated construction, respiratory therapy system 2000 includes respiratory therapy apparatus 2100. The respiratory therapy apparatus may include a flow generator 2101.

The illustrated flow generator 2101 includes a gas inlet 2102 and a gas outlet 2104. The flow generator 2101 may include a blower 2106. Blower 2106 may draw gas from gas inlet 2102. In some constructions, the flow generator 2101 can include a source or container of compressed gas (e.g., air, oxygen, etc.). The vessel may include a valve that can be adjusted to control the flow of gas exiting the vessel. In some constructions, the flow generator 2101 may use such a compressed gas source and/or other gas sources in place of the blower 2106. In some constructions, the blower 2106 can be used in combination with another gas source. In some constructions, the blower 2106 can include a motorized blower or can include a bellows device or some other structure capable of generating a flow of gas. In some constructions, the flow generator 2101 draws in atmospheric gas through the gas inlet 2102. In some configurations, the flow generator 2101 is adapted to draw atmospheric gas through the gas inlet 2102 and receive other gases (e.g., oxygen, nitric oxide, carbon dioxide, etc.) through the same gas inlet 2102 or a different gas inlet. Other configurations are also possible.

The illustrated flow generator 2101 includes a user control interface 2108. The user control interface 2108 may include one or more buttons, knobs, dials, switches, levers, touch screens, speakers, displays, and/or other input or output modules that a user may use to input commands into the flow generator 2101 in order to view data and/or control operation of the flow generator 2101 and/or control operation of other aspects of the respiratory therapy system 2000.

The flow generator 2101 may direct gas through a gas outlet 2104 to a first conduit 2110. In the illustrated construction, a first conduit 2110 directs gas to a gas humidifier 2112. The gas humidifier is optional.

The gas humidifier 2112 is used to entrain moisture in the gas to provide a humidified gas stream. The illustrated gas humidifier 2112 includes a humidifier inlet 2116 and a humidifier outlet 2118. The gas humidifier 2112 may include, be configured to contain or contain water or other humidifying or humidifying agent (hereinafter referred to as water).

In some configurations, the gas humidifier 2112 includes a heating element (not shown). The heating element may be used to heat the water in the gas humidifier 2112 to promote evaporation of the water and/or entrainment in the gas stream and/or to increase the temperature of the gas passing through the gas humidifier 2112. The heating element may for example comprise a resistive metal heating plate. However, other heating elements are also contemplated. For example, the heating element may comprise a plastic electrically conductive heating plate or a chemical heating system with a controllable heat output.

In the illustrated construction, the gas humidifier 2112 includes a user control interface 2120. The user control interface 2120 includes one or more buttons, knobs, dials, switches, levers, touch screens, speakers, displays, and/or other input or output modules that a user may use to input commands into the gas humidifier 2112 to view data, and/or control operation of the gas humidifier 2112, and/or control operation of other aspects of the respiratory therapy system 2000.

In some constructions, the flow generator 2101 and the gas humidifier 2112 can share a housing 2126. In some constructions, the gas humidifier 2112 may share only a portion of the housing 2126 with the flow generator 2101. Other configurations are also possible.

In the illustrated configuration, the gas travels from the humidifier outlet 2118 to the second conduit 300. The second conduit 300 may include a conduit heater as described with respect to fig. 24. The duct heater may be used to add heat to the gas passing through the second duct 300. The heat may reduce or eliminate the likelihood of water entrained in the gas stream condensing along the walls of the second conduit 300. The catheter heater may include one or more resistive wires located in, on, around, or near the wall of the second catheter 300. In one or more configurations, one or more such resistance wires may be located outside of any gas pathway. In one or more configurations, one or more such resistive wires are not in direct contact with the gas passing through the second conduit 300. In one or more configurations, a wall or surface of the second conduit 300 mediates (intercede) between the one or more resistance wires and the gas passing through the second conduit 300.

The gas passing through the second conduit 300 may be delivered to the nasal interface 100. The nasal interface 100 may pneumatically connect the respiratory therapy system 100 to the airway of a patient. In some configurations, respiratory therapy system 2000 utilizes a dual-branch system that includes separate inspiratory and expiratory gas pathways that engage one or more airways of a patient.

In some constructions, a short length of tubing connects the nasal interface 100 to the second catheter 300. In some constructions, the short length of tubing may have smooth holes. For example, a flexible short length tube may connect the nasal interface to the second catheter 300. The short length of tubing connecting the nasal interface to the second conduit 300 may be breathable so that it allows vapor to be transmitted through the tube wall. In some constructions, the short length of tubing may incorporate one or more heating wires as described elsewhere herein. Smooth pores, whether heated or not, may improve the efficiency of delivering the atomized material, as described elsewhere herein.

The respiratory therapy device 2100 includes a nebulizer 2128. In some constructions, if a nebulizer 2128 is used, the flow generator 2101, the gas humidifier 2112, and the nebulizer 2128 can share a housing 2126. In some constructions, the nebulizer 2128 is separate from the housing 2126.

The nebulizer 2128 may be connected to a portion of the gas pathway that extends between the flow generator 2101 (which may include the gas inlet 2102) and the nasal interface 100, although other arrangements of the nebulizer 2128 or another nebulizer may be used. In some constructions, the nebulizer 2128 is not positioned in-line anywhere between the humidifier outlet 2118 and the nasal interface 100. Instead, the nebulizer 2128 is positioned upstream of the humidifier outlet 2118 or upstream of the inlet of the second conduit 2122. In some constructions, the nebulizer 2128 may be positioned upstream of an inlet into the humidifier. In some constructions, the nebulizer 2128 can be positioned between the gas stream source and the chamber.

The nebulizer 2128 may include substances (e.g., drugs, trace gases, etc.) that may be introduced into the gas stream. The substance may be captured in the gas stream and may be delivered to the airway of the patient with the breathing gas. The nebulizer 2128 may be coupled to a portion of the gas pathway by a conveyor 2130, which may include a conduit or adapter. Alternatively, the nebulizer 2128 may be directly engaged with the gas channel, which may eliminate the need for the conveyor 2130.

The respiratory therapy apparatus 2100 may include a controller 2113. The controller 2113 may be configured or programmed to control the operation of the device. For example, the controller 2113 may control components of the device including, but not limited to: the flow generator 2101 is operated to generate a flow of gas (gas stream) for delivery to a patient, the humidifier 2112 (if present) is operated to humidify and/or heat the generated flow of gas, the flow of oxygen into the flow generator blower is controlled, user inputs are received from the user interface 2108 and/or 2120 for reconfiguration of the device 2100 and/or user-defined operation, and information is output to the user (e.g., on a display).

The controller 2113 may control the flow generator 2101 to produce a gas flow of a desired flow rate. The controller 2113 may also control a supplemental oxygen inlet to allow supplemental oxygen to be delivered, the humidifier 2112 (if present) may humidify the gas stream and/or heat the gas stream to an appropriate level, and so forth. The controller 2113 may also control the operation of the atomizer 2128. The flow of gas is directed to the patient through the patient catheter 300 and the nasal interface 100. The controller 2113 can also control heating elements in the humidifier 2112 and/or heating elements in the patient conduit 300 to heat the gas to a desired temperature for a desired therapeutic level and/or comfort level of the patient. The controller 2113 may be programmed or may determine an appropriate target temperature for the gas flow. In some configurations, a gas mixture composition including supplemental oxygen and/or therapeutic drug administration may be provided through a supplemental oxygen inlet. The gas mixture composition may include oxygen, heliox, nitrogen, nitric oxide, carbon dioxide, argon, helium, methane, sulfur hexafluoride, and combinations thereof, and/or the supplemental gas may include aerosolized drug from nebulizer 2128.

In some constructions, the respiratory therapy device 2100 includes a gas inlet 2102, a gas outlet 2118, and a nebulizer 2128 for delivering one or more substances into the gas stream. The nasal interface 100 for use in the respiratory therapy system 2000 with the respiratory therapy device 2100 includes: a gas inlet 121 in fluid communication with the gas outlet 2118 to receive gas and one or more substances from the respiratory therapy apparatus; a first fork 111 and a second fork 112; and a gas manifold 120 including a gas inlet 121. The first prong 111 and the second prong 112 are in fluid communication with the gas inlet 121. The nasal interface 100 is configured to induce asymmetric gas flow at the nostrils of the patient.

Respiratory therapy system 2000 may include conduits 300, 320 (examples of which are described below) to receive gas and one or more substances from respiratory therapy device 2100 and deliver the gas and one or more substances to gas inlet 121 of nasal interface 100.

In the illustrated construction, respiratory therapy system 2000 may operate as follows. Gas may be drawn into flow generator 2101 through gas inlet 2102 due to rotation of an impeller of a motor of blower 2106. The gas is pushed out of the gas outlet 2104 and through the first conduit 2110. Gas enters the gas humidifier 2112 through a humidifier inlet 2116. Upon entering the gas humidifier 2112, the gas entrains moisture as it passes over or near the water in the gas humidifier 2112. The water is heated by the heating element, which helps to humidify and/or heat the gas passing through the gas humidifier 2112. The gas exits the gas humidifier 2112 through humidifier outlet 2118 and enters the second conduit 300. The gas receives one or more substances from the nebulizer 128 before entering the second conduit 300. Gas passes from the second conduit 300 to the nasal interface 100 where it is inhaled into the patient's airway to assist in the treatment of respiratory disorders.

Fig. 27 illustrates an exemplary type of tubing or conduit 300 that may be used to deliver gas to the nasal interface 100. The tubing or conduit 300 is shown with smooth holes 3021 or non-corrugated holes. This type of conduit is best described and shown in, for example, U.S. patent application publication No. 2014/0202462 (also disclosed as PCT publication No. WO2012/164407 A1) and PCT publication No. WO 2014/088430. The contents of these specifications are incorporated herein by reference in their entirety. As described therein, the conduit is formed from beads (beads) 3041 and small tubes or bubbles 3061. Typically, the peak to valley surface roughness of such pipes is of the order of 0.15-0.25 mm. In one configuration, the conduit or tube has an internal bore diameter of 13-14 mm. The two members 3041, 3061 combine to define a catheter or tube having a lumen with minimal surface deviation. In some constructions, the bead 304 comprises wire 3081. One or more wires may be used to heat the conduit wall rather than being positioned within the flow being conveyed by the conduit or pipe 300. In the illustrated construction, the bead 3041 includes four wires 3081. In some constructions, the bead 304 may comprise two strands 3081. Other numbers of wires may also be used.

Fig. 28 shows an alternative exemplary type of tubing or conduit 320 that may be used to deliver gas to the nasal interface 100. Referring to fig. 28, the conduit or pipe 320 is shown as a bellows. In one configuration, the conduit or tube 320 has an inner bore diameter of 20-21 mm. The bellows 320 includes a deep trench 322 along a wall 324 of the conduit 320. In many cases, the groove 322 results in one or more helical discontinuities that extend along the length of the lumen defined by the wall 324. Thus, the inner surface of the conduit or tube is significantly rougher than the smooth bore tube 300 shown in fig. 26. Typically, the corrugated conduit or tubing has a peak to valley surface roughness of about 1.5-2.5mm. In the configuration shown in fig. 28, one or more heater wires 326 may also be coiled and positioned in direct contact with the flow of gas through the lumen. When the wire is located within the gas flow path, the heating wire increases by 2-3mm of increased "surface roughness", although this is merely an estimate of the effect of the heating wire being positioned within the gas flow path.

The use of a smooth-hole heating tube 300 as shown in fig. 27 for delivering a drug from the nebulizer 2128 described above results in a significant increase in drug delivery efficiency as compared to the use of a more conventional heated breathing tube 320 as shown in fig. 28. The improvement in efficiency is believed to be due to the substantial reduction in the amount of aerosolized drug captured within the channels 322 and exposed heater wire 326 of the more conventional heated breathing tube 320. For example, it has been estimated, for example and without limitation, that 300% more of the aerosolized drug is captured by the surface than the drug held within the smooth-bore heated breathing tube 300 as shown in fig. 27. It is believed that the deposition process, such as shock, is reduced due to less swirl in the flow and less obstruction (which obstruction presents an effective roughness).

In some configurations, delivery efficiency is found to decrease when the flow rate exceeds the optimal flow rate. In other words, at some high flow rates above 30lpm, the flow rate is inversely proportional to the nebulization efficiency to some extent (i.e., high flow rates result in more drug being trapped within the circuit than delivered to the patient).

With the nasal cannula 100 having nasal prongs 111, 112, for equal dead space, a reduction in flow rate is possible, which may improve the provision of respiratory therapy with aerosolized medicament. Due to the smoother flow transition, the aerosolized drug may be less likely to be "knocked out" in which a portion of the drug is deposited on the inner surface of the flow path rather than being delivered to the patient, or otherwise lost due to impact on the surface. With the partial unidirectional flow provided by the nasal interface 100, less drug is wasted than would otherwise be possible when the patient exhales against the flow. Other aspects of the nasal cannula 100 with prongs 111, 112 (including the cross-sectional area of the prongs and the relationship of these cross-sectional areas) may improve the provision of respiratory therapy with aerosolized medicament.

The patient interface 10 and nasal interface 100 used in the respiratory therapy system 2000 may have any one or more of the features and/or functions described herein with respect to the nasal interface 100.

The respiratory therapy system 2000 may have any one or more of the features and/or functions of the system described in PCT publication No. WO2016/085354 or U.S. patent application publication No. 2017/0312472. The contents of these specifications are incorporated herein by reference in their entirety.

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 described 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 to practice the present disclosure. Accordingly, it is intended that the scope of the disclosure be limited only by the claims appended hereto.

For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements in the disclosure. However, for convenience, certain features that are present in some figures of the present disclosure or that are annotated with reference numerals are not shown or annotated in other figures of the present disclosure. Unless the context clearly requires otherwise, these omissions should not be construed to mean that features omitted from the figures of one drawing are not equivalently incorporated into or implemented in the construction of the disclosed methods, apparatuses and systems as related to or as embodied in other drawings. Conversely, the presence of certain features in some of the figures of the present disclosure should not be assumed to mean that the disclosed methods, apparatuses, and systems related to or embodied in these figures must include these features unless the context clearly requires otherwise.

Clause of (b)

Additional embodiments are included in the following clauses or numbering statements.

1.A nasal interface, comprising:

i. A first fork having a first base and a first end;

a second fork having a second base and a second end;

A gas manifold comprising a manifold chamber and a gas inlet; and

At least one element positioned within the first prong, the second prong, or the manifold chamber;

b. wherein the at least one element is configured to increase resistance to gas flow traveling through at least one of the first prong, the second prong, or the manifold chamber, and

C. wherein the gas inlet is in fluid communication with the gas delivery conduit or is configured to be in fluid communication with the gas delivery conduit.

2. The nasal interface of clause 1, wherein the increase in resistance to gas flow is configured to cause asymmetric gas flow at the first prong and the second prong.

3. The nasal interface of clause 1 or clause 2, wherein the at least one element is a second binary element positioned within a second binary.

4. The nasal interface of clause 3, wherein the second prong element is configured to increase resistance to gas flow traveling through the second prong.

5. The nasal interface of clause 3 or clause 4, wherein the second prong is positioned at the second base.

6. The nasal interface of any one of clauses 1-5, wherein the second base of the second prong comprises an inlet to a flow path formed by a wall of the second prong.

7. The nasal interface according to any one of clauses 1-6, wherein the at least one element is a manifold element, wherein the manifold element is positioned within a manifold chamber of the gas manifold.

8. The nasal interface of clause 7, wherein the manifold element is configured to increase resistance to gas flow traveling through the manifold chamber.

9. The nasal interface according to any one of clauses 1-8, wherein the gas flow is substantially in a direction from the gas manifold inlet, through the gas manifold chamber, and into the flow path of the first prong and/or the second prong.

10. The nasal interface of clause 7 or clause 8, wherein the manifold element is positioned substantially at the center of the manifold chamber.

11. The nasal interface of any one of clauses 3-5, wherein the nasal interface comprises a first prong element, wherein the first prong element is positioned within the first prong.

12. The nasal interface of clause 11, wherein the first prong element is configured to increase resistance to gas flow traveling through the first prong.

13. The nasal interface of clause 11 or clause 12, wherein the first prong element is positioned at the first base of the first prong.

14. The nasal interface of clause 12, wherein the first prong element provides a different resistance to gas flow than the second prong element.

15. The nasal interface according to any one of clauses 1-14, wherein the gas delivery conduit is located between the patient conduit and the gas inlet.

16. The nasal interface according to any one of clauses 1-15, wherein the gas manifold is integrally formed with, or coupled to, the gas delivery conduit.

17. The nasal interface of any one of clauses 1-16, wherein the gas manifold comprises a manifold width, and wherein the manifold width is as large as or greater than an inner diameter of at least one of the first prong or the second prong.

18. The nasal interface according to any one of clauses 1-17, wherein the nasal interface comprises a cannula body comprising the first prong and the second prong, and wherein an outer surface of the cannula body between the first prong and the second prong comprises a recess to receive a portion of a patient's nose and to reduce pressure on an underside of the received portion.

19. The nasal interface according to any one of clauses 1-18, wherein at least one of the first prong or the second prong is sized to maintain a sufficient gap between an outer surface of the at least one prong and the patient's skin to avoid sealing a gas path between the nasal interface and the patient.

20. The nasal interface according to any one of clauses 1-19, wherein at least the first prong or the second prong is made of an elastomeric material that enables the first prong to deform and set its shape in use in response to temperature and contact with the patient's nostril.

21. The nasal interface according to any one of clauses 1-20, wherein at least one of the first prong or the second prong is not made of silicone.

22. The nasal interface of any one of clauses 1-21, wherein at least one of the first prong or the second prong is made of a thermoplastic elastomer.

23. The nasal interface according to any one of clauses 1-22, wherein the gas manifold includes a flow channel having a gas flow direction substantially perpendicular to a gas flow path through the first prong and the second prong.

24. The nasal interface of clause 7 or 8, wherein the manifold element comprises a manifold aperture for the passage of a gas flow therethrough, wherein the manifold aperture has a smaller cross-sectional opening than the manifold chamber for the gas flow.

25. The nasal interface of any one of clauses 3-5, wherein the second prong element includes a second aperture for the passage of a gas flow therethrough, wherein the second aperture has a smaller cross-sectional opening than the second prong for the gas flow.

26. The nasal interface of clause 24 or clause 25, wherein the manifold hole and/or the second hole are formed in a plate or wall.

27. The nasal interface of clause 26, wherein the plate or wall has an inlet surface and an outlet surface, the manifold hole and/or the second hole being formed between the inlet surface and the outlet surface.

28. The nasal interface of clause 27, wherein the gas flow is in a direction from the inlet surface to the outlet surface through the manifold aperture and/or the second aperture.

29. The nasal interface of clause 27 or 28, wherein the transition between the outlet surface and the manifold hole and/or the second hole is tapered.

30. The nasal interface according to any one of clauses 27-29, wherein a transition between the inlet surface and the manifold aperture and/or the second aperture is substantially right angle.

31. The nasal interface according to any one of clauses 27-29, wherein the transition between the inlet surface and the manifold hole and/or the second hole is tapered, wherein the taper angle of the outlet surface is greater than the taper angle of the inlet surface.

32. The nasal interface according to any one of clauses 27-29, wherein the transition between the inlet surface and the manifold hole and/or the second hole is a substantially sharp corner.

33. The nasal interface according to any one of clauses 26-32, wherein the at least one manifold hole and/or the second hole is a gap, cut, or slit extending vertically longitudinally through the plate or wall.

34. The nasal interface according to any one of clauses 26-32, wherein the at least one manifold hole and/or the second hole is a gap, cut, or slit extending horizontally and longitudinally through the plate or wall.

35. The nasal interface according to any one of clauses 24-34, wherein at least one manifold hole and/or the second hole is a substantially circular perforation.

36. The nasal interface according to any one of clauses 24-35, wherein at least one manifold hole and/or the second hole includes a perforation pattern.

37. The nasal interface according to any one of clauses 26-34, wherein the plate or wall of at least one manifold aperture and/or second aperture comprises a porous medium.

38. The nasal interface of any one of clauses 1-37, wherein the at least one element comprises a valve.

39. The nasal interface of clause 38, wherein the valve is configured to open only at a threshold pressure or a threshold flow rate.

40. The nasal interface of clause 38 or clause 39, wherein the valve is configured to provide a defined pressure drop in the flow path.

41. The nasal interface according to any one of clauses 38-40, wherein the valve is a duckbill valve.

42. The nasal interface according to any one of clauses 1-41, wherein the at least one element includes a nozzle.

43. The nasal interface of clause 42, wherein the nozzle is configured to provide a defined pressure drop in the flow path.

44. The nasal interface of clause 7 or clause 8, wherein the manifold element is configured to be adjusted via manual actuation to increase or decrease the degree of restriction by the manifold element.

45. The nasal interface of clause 44, wherein the manifold element is configured to be slidably movable in an upstream-downstream direction.

46. The nasal interface of clause 44, wherein the manifold element comprises a rotatable member having a helical thread.

47. The nasal interface of clause 45 or clause 46, wherein the manifold element further comprises an outer portion located outside of the gas manifold of the nasal interface.

48. The nasal interface of clause 47, wherein the manifold element is configured to be rotationally movable such that when the outer portion is rotated, the manifold element translates vertically into or out of the manifold chamber flow path, thereby increasing or decreasing, respectively, the degree of flow restriction in the flow path.

49. The nasal interface according to any one of clauses 1-48, wherein the gas manifold includes an opening at a wall generally opposite the gas inlet of the gas manifold and/or generally opposite the second base of the second prong.

50. The nasal interface of clause 49, wherein the opening comprises one or more holes.

51. The nasal interface of clause 50, wherein the number and diameter of the apertures are configured to provide a defined pressure drop.

52. The nasal interface according to any one of clauses 49-51, wherein the opening in the wall of the manifold is pneumatically connected to a member configured to provide a defined pressure drop.

53. The nasal interface of clause 52, wherein the component is at least one of a porous medium, a nozzle, a pressure relief valve, an auxiliary tube, or a bubble CPAP bubbling chamber.

54. The nasal interface of any one of clauses 1-53, wherein the axis of the gas inlet is coaxial with respect to the axis of at least one of the first prong or the second prong.

55. The nasal interface of any one of clauses 1-53, wherein the angle of the axis of the gas inlet is perpendicular relative to the axis of at least the first prong or the second prong.

56. The nasal interface of any one of clauses 1-55, wherein the gas manifold comprises a second gas inlet.

57. The nasal interface according to any one of clauses 1-56, wherein the nasal interface includes an auxiliary gas inlet to induce or promote asymmetric gas flow at the first prong and the second prong.

58. The nasal interface of clause 57, wherein the auxiliary gas inlet terminates in a first prong or a second prong.

59. The nasal interface of clause 57 or 58, wherein the auxiliary gas inlet is in fluid communication with the auxiliary gas delivery conduit.

60. The nasal interface of any one of clauses 57-59, wherein at least one of the gas inlet or the gas delivery conduit comprises a lumen having a first internal cross-sectional area, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit comprises a lumen having a second internal cross-sectional area.

61. The nasal interface of clause 60, wherein one or both of the first and second internal cross-sectional areas are substantially circular.

62. The nasal interface of clause 61 or clause 62, wherein the first internal cross-sectional area and the second internal cross-sectional area are different.

63. The nasal interface of clause 63, wherein the second internal cross-sectional area is less than the internal cross-sectional area of the first prong or the second prong.

64. The nasal interface of clause 59, wherein the gas delivery conduit and the auxiliary gas delivery conduit are disposed on the same side of the manifold chamber.

65. The nasal interface of clause 59, wherein the auxiliary gas delivery conduit is positioned in the gas delivery conduit.

66. The nasal interface of clause 59, wherein at least one of the gas inlet or the gas delivery conduit comprises a first length and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit comprises a second length.

67. The nasal interface of clause 66, wherein the first length and the second length are unequal to cause asymmetric gas flow at the first prong and the second prong.

68. The nasal interface of clause 66 or clause 67, wherein the first length is longer than the second length to induce or promote asymmetric gas flow at the first prong and the second prong.

69. The nasal interface of clause 66 or clause 67, wherein the first length is shorter than the second length to induce or promote asymmetric gas flow at the first and second prongs.

70. The nasal interface of clause 59, wherein the gas delivery conduit is in communication with a first gas stream and the auxiliary gas delivery conduit is in communication with a second gas stream.

71. The nasal interface of clause 70, wherein the first gas stream has a different flow rate than the second gas stream.

72. The nasal interface of clause 70 or clause 71, wherein the resultant flow direction between the gas manifold and the first gas stream is a different flow direction than the resultant flow direction between the gas manifold and the second gas stream.

73. The nasal interface of any one of clauses 70-72, wherein one of the first or second gas streams is an inhalation stream.

74. The nasal interface of any one of clauses 70-73, wherein the gas pressure of the first gas stream is different than the gas pressure of the second gas stream.

75. The nasal interface of clause 74, wherein the negative gas pressure relative to the environment is formed by the first gas flow or the second gas flow.

76. A nasal interface, comprising:

i. A first fork having a first base and a first end;

A second fork having a second base and a second end; and

A gas manifold comprising:

1. A manifold chamber;

2.A first gas inlet; and

3. A second gas inlet is provided for the gas,

B. Wherein the first gas inlet and the second gas inlet are in fluid communication with the first gas delivery conduit and the second gas delivery conduit, respectively,

I. wherein the nasal interface is configured to induce asymmetric gas flow at the first prong and the second prong.

77. The nasal interface of clause 76, wherein the first and second gas inlets are disposed on opposite sides of the manifold chamber.

78. The nasal interface of clause 76 or 77, wherein the first gas inlet is closer to the first prong than the second gas inlet, and wherein the second gas inlet is closer to the second prong than the first gas inlet.

79. The nasal interface according to any one of clauses 76-78, wherein at least one of the first gas inlet and the first gas delivery conduit is formed as a unitary structure, or the second gas inlet and the second gas delivery conduit are formed as a unitary structure.

80. The nasal interface according to any one of clauses 76-79, wherein the first gas delivery conduit is in communication with the first gas stream and the second gas delivery conduit is in communication with the second gas stream.

81. The nasal interface of clause 80, wherein the first gas stream has a different flow rate than the second gas stream.

82. The nasal interface of clause 80 or clause 81, wherein the resultant flow direction between the gas manifold and the first gas stream is a different flow direction than the resultant flow direction between the gas manifold and the second gas stream.

83. The nasal interface of any one of clauses 80-82, wherein one of the first or second gas streams is an inhalation stream.

84. The nasal interface of any one of clauses 80-83, wherein the gas pressure of the first gas stream is different than the gas pressure of the second gas stream.

85. The nasal interface of clause 84, wherein the negative gas pressure relative to the environment is formed by the first gas flow or the second gas flow.

86. The nasal interface of any one of clauses 76-85, wherein at least one of the first gas inlet or the first gas delivery conduit comprises a lumen having a first internal cross-sectional area and at least one of the second gas inlet or the second gas delivery conduit comprises a lumen having a second internal cross-sectional area.

87. The nasal interface of clause 86, wherein one or both of the first and second internal cross-sectional areas are substantially circular.

88. The nasal interface of clause 86, wherein one or both of the first and second internal cross-sectional areas are substantially non-circular.

89. The nasal interface of any one of clauses 86-88, wherein the first and second internal cross-sectional areas are unequal to induce asymmetric gas flow at the first and second prongs.

90. The nasal interface of any one of clauses 86-89, wherein the first internal cross-sectional area is greater than the second internal cross-sectional area to induce asymmetric gas flow at the first prong and the second prong.

91. The nasal interface of any one of clauses 86-89, wherein the first internal cross-sectional area is less than the second internal cross-sectional area to induce asymmetric gas flow at the first prong and the second prong.

92. The nasal interface of any one of clauses 76-91, wherein at least one of the first gas inlet or the first gas delivery conduit comprises a first length and at least one of the second gas inlet or the second gas delivery conduit comprises a second length.

93. The nasal interface of clause 92, wherein the first length and the second length are unequal to cause asymmetric gas flow at the first prong and the second prong.

94. The nasal interface of clause 92 or clause 93, wherein the first length is longer than the second length to induce asymmetric gas flow at the first prong and the second prong.

95. The nasal interface of clause 92 or clause 93, wherein the first length is shorter than the second length to induce asymmetric gas flow at the first and second prongs.

96. The nasal interface of any one of clauses 76-95, wherein the inner surface of at least one of the first gas inlet or the first gas delivery conduit comprises a first pattern of relief features.

97. The nasal interface of any one of clauses 76-96, wherein an inner surface of at least one of the second gas inlet or the second gas delivery conduit comprises a second pattern of relief features.

98. The nasal interface of clause 97 when dependent on clause 96, wherein the first relief feature pattern is substantially rougher than the second relief feature pattern to cause asymmetric gas flow at the first and second prongs.

99. The nasal interface of clause 97 when dependent on clause 96, wherein the first relief feature pattern is substantially smoother than the second relief feature pattern to cause asymmetric gas flow at the first and second prongs.

100. The nasal interface of any one of clauses 96-99, wherein the relief feature pattern comprises one or more of the following: pits, projections, ribs, and/or fins.

101. The nasal interface of any one of clauses 76-100, wherein the axis of at least one of the first gas inlet or the second gas inlet is coaxial relative to the axis of at least one of the first prong or the second prong.

102. The nasal interface of any one of clauses 76-100, wherein the angle of the axis of the first gas inlet and/or the second gas inlet is perpendicular relative to the axis of at least one of the first prong or the second prong.

103. The nasal interface according to any one of clauses 76-102, comprising at least one of:

(i) A first fork element positioned within the first fork;

(ii) A second fork element positioned within the second fork;

(iii) A manifold element positioned in the manifold chamber and between the first base of the first fork and the second base of the second fork;

(iv) A first gas inlet element positioned at a first gas inlet to the gas manifold; or (b)

(V) A second gas inlet element positioned at a second gas inlet to the gas manifold,

A. Wherein the first prong element, the second prong element, the manifold element, the first gas inlet element and/or the second gas inlet element are each configured to increase resistance to gas flow into the corresponding element to cause asymmetric gas flow at the first prong and the second prong.

104. The nasal interface of clause 103, comprising the first and second gas inlet elements each configured to increase a flow resistance of a gas flow entering the gas manifold through the first and second gas inlets, respectively.

105. The nasal interface of clause 103, comprising the first prong element and the second prong element each configured to increase a flow resistance of the gas flow into the first prong and the second prong, respectively.

106. The nasal interface of clause 103, comprising the manifold element and the first gas inlet element each configured to increase a flow resistance of a gas flow within the manifold chamber and into the gas manifold through the manifold element and the first gas inlet element, respectively.

107. The nasal interface of clause 103, comprising the manifold element and the second gas inlet element each configured to increase a flow resistance of a gas flow within the manifold chamber and into the gas manifold through the manifold element and the second gas inlet element, respectively.

108. The nasal interface of any one of clauses 103-107, wherein at least one of the first prong element, the second prong element, the manifold element, the first gas inlet element, or the second gas inlet element, when present, comprises an aperture for a passage for reducing gas flow.

109. The nasal interface of clause 108, wherein the aperture is formed in a plate or wall.

110. The nasal interface of clause 109, wherein the plate or wall has an inlet surface and an outlet surface forming a hole therebetween.

111. The nasal interface of clause 110, wherein the gas flow is in a direction from the inlet surface to the outlet surface through the aperture.

112. The nasal interface of clause 109 or clause 110, wherein the transition between the outlet surface and the aperture is tapered.

113. The nasal interface according to any one of clauses 109-112, wherein a transition between the inlet surface and the aperture is substantially right-angled.

114. The nasal interface of any one of clauses 109-112, wherein the transition between the inlet surface and the aperture is tapered, wherein the taper angle of the outlet surface is greater than the taper angle of the inlet surface.

115. The nasal interface according to any one of clauses 109-112, wherein the transition between the inlet surface and the aperture is a substantially sharp corner.

116. The nasal interface according to any one of clauses 109-115, wherein at least one aperture is a gap, cut, or slit extending longitudinally vertically through the plate or wall.

117. The nasal interface according to any one of clauses 109-115, wherein at least one aperture is a gap, cut, or slit extending longitudinally horizontally through the plate or wall.

118. The nasal interface of any one of clauses 108-115, wherein at least one aperture is a substantially circular perforation.

119. The nasal interface of any one of clauses 108-115, wherein at least one aperture comprises a perforation pattern.

120. The nasal interface of any one of clauses 109-115, wherein the plate or wall of at least one aperture comprises a porous medium.

121. The nasal interface of any one of clauses 103-108, wherein at least one of the first prong element, the second prong element, the manifold element, the first gas inlet element, or the second gas inlet element, when present, comprises a valve.

122. The nasal interface of clause 121, wherein the valve is configured to open only at a threshold pressure or a threshold flow rate.

123. The nasal interface of clause 121 or 122, wherein the valve is configured to provide a defined pressure drop in the flow path.

124. The nasal interface of any one of clauses 121-123, wherein the valve is a duckbill valve.

125. The nasal interface of any one of clauses 103-124, wherein at least one of the first prong element, the second prong element, the manifold element, the first gas inlet element, or the second gas inlet element, when present, comprises a nozzle.

126. The nasal interface of clause 125, wherein the nozzle is configured to provide a defined pressure drop in the flow path.

127. The nasal interface of any one of clauses 103-126, wherein, when present, at least one of the first prong element, the second prong element, the manifold element, the first gas inlet element, or the second gas inlet element is configured to be adjusted by manual actuation to increase or decrease the degree of restriction by the elements.

128. The nasal interface of clause 127, wherein the element is configured to slidably move in an upstream-downstream direction.

129. The nasal interface of clause 128, wherein the element comprises a rotatable member having a helical thread.

130. The nasal interface of clause 129, wherein the element further comprises an outer portion located outside of the nasal interface.

131. The nasal interface of clause 130, wherein the element is configured to be rotatably movable such that when the outer portion is rotated, the element translates vertically into or out of the flow path, thereby increasing or decreasing, respectively, the degree of flow restriction in the flow path.

132. A nasal interface, comprising:

i. a first fork and a second fork;

a gas manifold comprising a manifold chamber and a gas inlet in fluid communication with, or configured to be in fluid communication with, a gas delivery conduit; and

At least one flow directing element formed as part of at least one of a manifold chamber, a gas inlet, or a gas delivery conduit;

b. Wherein the at least one flow directing element is configured to direct a flow of gas to one of the first prong or the second prong to create an asymmetric flow of gas.

133. The nasal interface of clause 132, wherein the flow directing element is configured to provide a greater dynamic pressure at the first prong in use and a lesser dynamic pressure at the second prong in use to create an asymmetric gas flow.

134. The nasal interface of clause 132 or clause 133, wherein at least one of the first prong or the second prong is sized to maintain a sufficient gap between an outer surface of the at least one prong and the patient's skin to avoid sealing a gas path between the nasal interface and the patient.

135. The nasal interface of any one of clauses 132-134, wherein the first prong and the second prong are in fluid communication with the manifold chamber.

136. The nasal interface of any one of clauses 132-135, wherein the gas inlet is positioned in the manifold chamber opposite at least one of the first prong or the second prong.

137. The nasal interface of any one of clauses 132-137, wherein the axis of the gas inlet is coaxial relative to the axis of at least one of the first prong or the second prong.

138. The nasal interface of any one of clauses 132-136, wherein the angle of the axis of the gas inlet is perpendicular relative to the axis of at least one of the first prong or the second prong.

139. The nasal interface of any one of clauses 134-138, wherein the at least one flow directing element is positioned within a manifold chamber of the gas.

140. The nasal interface of any one of clauses 134-138, wherein the at least one flow directing element is positioned within a gas delivery conduit.

141. The nasal interface of clause 140, wherein the at least one flow directing element is positioned within the gas delivery conduit where the gas delivery conduit meets the gas inlet.

142. The nasal interface of any one of clauses 134-141, wherein the at least one flow directing element comprises at least one angled protrusion, wherein the protrusion is configured to direct a flow of gas from the gas inlet toward one of the first prong or the second prong.

143. The nasal interface of clause 142, wherein the at least one flow directing element further comprises an angled second protrusion positioned opposite the first protrusion in the flow path and likewise configured to direct the flow of gas from the gas inlet toward one of the first prong or the second prong.

144. The nasal interface of any one of clauses 134-143, comprising a second flow directing element positioned in the gas manifold at an inlet to one of the first prong or the second prong.

145. The nasal interface of clause 144, wherein the second flow directing element is configured to direct the flow of gas from the gas inlet toward one of the first prong or the second prong.

146. The nasal interface of clause 144 or clause 145, wherein the second flow directing element is configured to direct the flow of exhaled gas from the first prong or the second prong to the opposite prong.

147. The nasal interface of clause 144 or clause 145, wherein the second flow directing element comprises at least one angled protrusion, wherein the protrusion is configured to direct a flow of gas from the gas inlet toward one of the first prong or the second prong, and is configured to direct a flow of exhaled gas from the first prong or the second prong to the opposite prong.

148. The nasal interface of any one of clauses 134-147, wherein the gas inlet is positioned in the manifold chamber at a substantially central location between the first prong and the second prong.

149. The nasal interface of any one of clauses 134-148, wherein the at least one flow directing element is positioned within the gas manifold chamber and proximate to the first prong.

150. The nasal interface of any one of clauses 134-149, wherein the at least one flow directing element is configured to direct a flow of gas from the gas delivery conduit toward an inlet of the first prong.

151. The nasal interface of any one of clauses 144-147, wherein the second flow directing element is configured to direct a flow of gas from the inlet of the first prong into the flow path of the first prong.

152. The nasal interface of any one of clauses 134-151, wherein the at least one flow directing element is positioned within the manifold chamber of the gas and proximate to the second prong.

153. The nasal interface of any one of clauses 134-148, wherein the at least one flow directing element is configured to direct a flow of gas from the gas delivery conduit toward an inlet of the second prong.

154. The nasal interface of any one of clauses 144-147, wherein the second flow directing element is configured to direct a flow of gas from an inlet of the second prong into a flow path of the second prong.

155. The nasal interface of any one of clauses 134-154, comprising at least one of:

(i) A first fork element positioned within the first fork;

(ii) A second fork element positioned within the second fork;

(iii) A manifold element positioned within the manifold chamber and between the first base of the first fork and the second base of the second fork;

b. Wherein the first fork element, the second fork element and/or the manifold element are each configured to increase the flow resistance of the gas flow into the respective element.

156. The nasal interface of clause 155, comprising the first prong element and the second prong element each configured to increase a flow resistance of the gas flow into the first prong and the second prong, respectively.

157. The nasal interface of clause 155, comprising the manifold element and the second prong element, each configured to increase the flow resistance of the gas flow through the second prong element and the manifold element into the second prong and the manifold chamber, respectively.

158. The nasal interface of any one of clauses 155-157, wherein at least one of the first prong element, the second prong element, and/or the manifold element, when present, comprises an aperture for reducing the passage of gas flow.

159. The nasal interface of clause 158, wherein the aperture is formed in a plate or wall.

160. The nasal interface of clause 159, wherein the plate or wall has an inlet surface and an outlet surface forming the aperture therebetween.

161. The nasal interface of clause 160, wherein the gas flow is in a direction from the inlet surface to the outlet surface through the aperture.

162. The nasal interface of clause 160 or clause 161, wherein the transition between the outlet surface and the aperture is tapered.

163. The nasal interface of any one of clauses 160-162, wherein the transition between the inlet surface and the aperture is substantially right angle.

164. The nasal interface of any one of clauses 160-162, wherein the transition between the inlet surface and the aperture is tapered, wherein the taper angle of the outlet surface is greater than the taper angle of the inlet surface.

165. The nasal interface of any one of clauses 160-162, wherein the transition between the inlet surface and the aperture is substantially a sharp corner.

166. The nasal interface of any one of clauses 159-165, wherein at least one aperture is a gap, cut, or slit extending longitudinally vertically through the plate or wall.

167. The nasal interface of any one of clauses 159-165, wherein at least one aperture is a gap, cut, or slit extending longitudinally horizontally through the plate or wall.

168. The nasal interface of any one of clauses 158-167, wherein at least one aperture is a substantially circular perforation.

169. The nasal interface of any one of clauses 158-167, wherein at least one aperture comprises a perforation pattern.

170. The nasal interface of any one of clauses 159-169, wherein the plate or wall of at least one aperture comprises a porous medium.

171. The nasal interface of any one of clauses 155-170, wherein at least one of the first prong element, the second prong element, and/or the manifold element, when present, comprises a valve.

172. The nasal interface of clause 171, wherein the valve is configured to open only at a threshold pressure or a threshold flow rate.

173. The nasal interface of clause 171 or 172, wherein the valve is configured to provide a defined pressure drop in the flow path.

174. The nasal interface of any one of clauses 171-173, wherein the valve is a duckbill valve.

175. The nasal interface of any one of clauses 155-174, wherein at least one of the first prong element, the second prong element, and/or the manifold element, when present, comprises a nozzle.

176. The nasal interface of clause 175, wherein the nozzle is configured to provide a defined pressure drop in the flow path.

177. The nasal interface of any one of clauses 155-176, wherein at least one of the first prong element, the second prong element, and/or the manifold element, when present, is configured to be adjusted by manual actuation to increase or decrease the degree of restriction by the elements.

178. The nasal interface of clause 177, wherein the element is configured to slidably move in an upstream-downstream direction.

179. The nasal interface of clause 177, wherein the element comprises a rotatable member having a helical thread.

180. The nasal interface of clause 179, wherein the element further comprises an outer portion located outside of the nasal interface.

181. The nasal interface of clause 180, wherein the element is configured to be rotatably movable such that when the outer portion is rotated, the element translates vertically into or out of the flow path, thereby increasing or decreasing, respectively, the degree of flow restriction in the flow path.

182. The nasal interface of any one of clauses 1-181, wherein the first prong has a first prong length and the second prong has a second prong length, and the first prong length is different from the second prong length.

183. The nasal interface of clause 182, wherein the first prong length is longer than the second prong length to induce or promote asymmetric gas flow at the first prong and the second prong.

184. The nasal interface of clauses 182 or 183, wherein the first prong length is shorter than the second prong length to induce or promote asymmetric gas flow at the first prong and the second prong.

185. The nasal interface of any one of clauses 1-184, wherein the first prong has a first prong cross-sectional width and the second prong has a second prong cross-sectional width, and wherein the first prong cross-sectional width is different than the second prong cross-sectional width.

186. The nasal interface of clause 185, wherein the first prong cross-sectional width is greater than the second prong cross-sectional width to induce or promote asymmetric gas flow at the first prong and the second prong.

187. The nasal interface of clause 185, wherein the first prong cross-sectional width is less than the second prong cross-sectional width to induce or promote asymmetric gas flow at the first prong and the second prong.

188. The nasal interface of any one of clauses 1-187, wherein the first prong has a first end and the second prong has a second end, and wherein the geometry of the first end and the geometry of the second end are different to cause or promote asymmetric gas flow at the first prong and the second prong.

189. The nasal interface of clause 188, wherein at least one of the first or second ends narrows or tapers to form a nozzle shape.

190. The nasal interface of clause 188 or clause 189, wherein at least one of the first end or the second end widens or tapers to form a diffuser shape.

191. The nasal interface of any one of clauses 1-190, wherein the first prong has a first inner surface and the second prong has a second inner surface, wherein at least one of the first inner surface or the second inner surface has a surface feature configured to affect an internal flow resistance of the at least one first prong or the second prong.

192. The nasal interface of clause 191, wherein the surface feature is a ridge formed in a concentric pattern as a ring, spiral, or band around the first or second inner surface.

193. The nasal interface of clauses 190 or 191, wherein the surface features are fins formed as lines, strips, or bars in a substantially axial direction pattern along the first or second inner surface.

194. The nasal interface of any one of clauses 191-193, wherein when surface features are present on the first and second inner surfaces, the surface features are different to cause asymmetric gas flow at the first and second prongs.

195. The nasal interface of any one of clauses 1-194, wherein at least one of the first prong and the second prong is a non-circular cross-sectional shape configured to affect an internal flow resistance of the at least one first prong or the second prong.

196. The nasal interface of clause 195, wherein the non-circular cross-sectional shape is reduced by the size of the circular cross-sectional shape removed therefrom.

197. The nasal interface of clause 195, wherein the non-circular cross-sectional shape is substantially U-shaped.

198. The nasal interface of clause 195, wherein the non-circular cross-sectional shape is substantially polygonal.

199. The nasal interface of any one of clauses 195-198, wherein when a non-circular cross-sectional shape is present on each of the first and second prongs, the non-circular cross-sectional shape is different to cause or promote asymmetric gas flow at the first and second prongs.

200. The nasal interface of any one of clauses 1-199, wherein at least one of the first prong and the second prong comprises a base restriction at the base of the prong, the base restriction configured to affect an internal flow resistance in the at least one first prong or the second prong.

201. The nasal interface of clause 200, wherein the base restriction is a nozzle or diffuser formed at the base of the prongs.

202. The nasal interface of clause 200 or clause 201, wherein when there is a base restriction on the first prong and the second prong, the base restriction is different to cause or promote asymmetric gas flow at the first prong and the second prong.

203. The nasal interface of any one of clauses 1-202, wherein at least one of the first prong and the second prong comprises a prong valve positioned within the prong, the prong valve configured to affect an internal flow resistance of the at least one first prong or the second prong.

204. The nasal interface of clause 203, wherein the fork valve is configured to restrict or prevent the flow of gas therethrough until the flow of gas exceeds a defined pressure.

205. The nasal interface of clause 203 or clause 204, wherein the fork valve is a duckbill valve.

206. The nasal interface of any one of clauses 203-205, wherein the fork valve is a one-way valve.

207. The nasal interface of any one of clauses 203-206, wherein when a fork valve is present in each of the first and second prongs, the fork valve has different characteristics to cause asymmetric gas flow at the first and second prongs.

208. The nasal interface of any one of clauses 1-207, further comprising a third prong, wherein the first prong, the second prong, and the third prong are spaced apart to be engageable as adjacent pairs into a nostril of a patient, wherein at least one of the first prong, the second prong, or the third prong has a different flow characteristic than the other prongs to induce or promote asymmetric gas flow at each prong.

209. The nasal interface of clause 208, further comprising a closure for releasably preventing gas flow through the first prong, the second prong, or the third prong.

210. A nasal interface, comprising:

i. A first fork having a first base and a first end;

a second fork having a second base and a second end;

a gas manifold;

a first gas inlet; and

V. an auxiliary gas inlet;

wherein the first gas inlet and the second gas inlet are in fluid communication with the first gas delivery conduit and the second gas delivery conduit, respectively;

wherein the nasal interface is configured to induce asymmetric gas flow at the first prong and the second prong.

211. The nasal interface of clause 210, wherein the first gas inlet terminates in a gas manifold.

212. The nasal interface of clauses 201 or 211, wherein the auxiliary gas inlet terminates in a first prong or a second prong.

213. The nasal interface of any one of clauses 210-212, wherein the auxiliary gas inlet is in fluid communication with the auxiliary gas delivery conduit.

214. The nasal interface of any one of clauses 210-213, wherein at least one of the first gas inlet or the gas delivery conduit comprises a lumen having a first internal cross-sectional area, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit comprises a lumen having a second internal cross-sectional area.

215. The nasal interface of clause 214, wherein one or both of the first and second internal cross-sectional areas are substantially circular.

216. The nasal interface of clauses 214 or 215, wherein the first internal cross-sectional area and the second internal cross-sectional area are different.

217. The nasal interface of clause 216, wherein the second internal cross-sectional area is less than the internal cross-sectional area of the first prong or the second prong.

218. The nasal interface of clause 213, wherein the gas delivery conduit and the auxiliary gas delivery conduit are disposed on the same side of the gas manifold.

219. The nasal interface of any one of clauses 213, wherein an auxiliary gas delivery conduit is located in the gas delivery conduit.

220. The nasal interface of clause 213, wherein at least one of the first gas inlet or the gas delivery conduit comprises a first length and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit comprises a second length.

221. The nasal interface of clause 220, wherein the first length and the second length are unequal to cause asymmetric gas flow at the first prong and the second prong.

222. The nasal interface of clause 220 or clause 221, wherein the first length is longer than the second length to induce or promote asymmetric gas flow at the first prong and the second prong.

223. The nasal interface of clause 220 or clause 221, wherein the first length is shorter than the second length to induce or promote asymmetric gas flow at the first prong and the second prong.

224. The nasal interface of clause 214, wherein the gas delivery conduit is in communication with a first gas stream and the auxiliary gas delivery conduit is in communication with a second gas stream.

225. The nasal interface of clause 224, wherein the first gas stream has a different flow rate than the second gas stream.

226. The nasal interface of clause 224 or 225, wherein the resultant flow direction between the gas manifold and the first gas stream is a different flow direction than the resultant flow direction between the gas manifold and the second gas stream.

227. The nasal interface of any one of clauses 224-226, wherein one of the first or second gas streams is an inhalation stream.

228. The nasal interface of any one of clauses 224-227, wherein the gas pressure of the first gas stream is different than the gas pressure of the second gas stream.

229. The nasal interface of clause 228, wherein the negative gas pressure relative to the environment is formed by the first gas flow or the second gas flow.

230. A patient interface comprising a nasal interface according to any one of clauses 1-229.

231. The patient interface according to clause 230, further comprising a headgear for maintaining the nasal interface on the patient's face.

232. The patient interface of clause 230 or 231, further comprising a gas delivery conduit in fluid communication with the gas inlet.

233. The patient interface of clause 232, wherein the gas delivery conduit is a gas permeable tube.

234. The patient interface of clause 233, wherein the gas manifold is integrally formed with, or coupled to, the gas delivery conduit.

235. The patient interface of any one of clauses 232-234, wherein the gas delivery conduit couples the gas inlet to a patient conduit that provides gas from the flow generator.

236. The patient interface of any one of clauses 232-235, further comprising a gas delivery conduit retaining clip.

237. A respiratory therapy system, comprising:

i. Respiratory therapy apparatus comprising:

A controller;

Blood oxygen saturation sensor;

Ambient air inlet;

v. oxygen inlet;

A valve in fluid communication with the oxygen inlet to control the flow of oxygen through the oxygen inlet; and

A gas outlet;

b. Wherein the controller is configured to control the valve based on at least one oxygen saturation measurement from the blood oxygen saturation sensor; and

I. A patient interface according to any one of clauses 230-236.

Claims

1.A nasal interface, comprising:

A first fork having a first base and a first end;

A second fork having a second base and a second end;

A gas manifold comprising a manifold chamber and a gas inlet; and

Wherein the at least one element is configured to increase resistance to gas flow traveling through at least one of the first prong, the second prong, or the manifold chamber, and

Wherein the gas inlet is in fluid communication with the gas delivery conduit or is configured to be in fluid communication with the gas delivery conduit.

2. The nasal interface of claim 1, wherein the increase in resistance to gas flow is configured to induce asymmetric gas flow at the first prong and the second prong.

3. A nasal interface according to claim 1 or claim 2, wherein the at least one element is a second prong element positioned within the second prong.

4. The nasal interface of claim 3, wherein the second prong element is configured to increase resistance to gas flow traveling through the second prong.

5. A nasal interface according to claim 3 or claim 4, wherein the second prong is positioned at the second base.

6. The nasal interface according to any one of claims 1-5, wherein the second base of the second prong includes an inlet to a flow passage formed by a wall of the second prong.

7. The nasal interface according to any one of claims 1-6, wherein the at least one element is a manifold element, wherein the manifold element is positioned within a manifold chamber of the gas manifold.

8. The nasal interface of claim 7, wherein the manifold element is configured to increase resistance to gas flow traveling through the manifold chamber.

9. A nasal interface according to any one of claims 1 to 8, wherein the flow of gas is substantially in a direction from the gas manifold inlet, through the gas manifold chamber, and into the flow passages of the first prong and/or the second prong.

10. A nasal interface according to claim 7 or claim 8, wherein the manifold element is positioned substantially at the centre of the manifold chamber.