DE19543248B4 - Apparatus for breathing assistance control - Google Patents

Abstract

Breath support device comprising:
A conduit (12) connected at one end to the atmosphere and to a source of pressurized air and at a second end to a mask adapted to bring a patient's pulmonary system into communication with said conduit;
A check valve (11) mounted in the aforesaid conduit so as to prevent the passage of air from the patient to the source of pressurized air during an exhalation phase,
a passage to the atmosphere (15) attached to the mask and capable of connecting the patient's pulmonary system to the atmosphere,
A valve (16) provided in said passage and adapted to open it during an exhalation phase,
- wherein the valve (16) is a valve with an elastic membrane (17) having a first side, a part of which is the inlet pressure of the patient's pulmonary system and the remaining part ...

Description

The present invention relates on an apparatus for breathing support.

The current techniques of breathing assistance are diverse and vary according to the needs of the patient.

In some cases, the patient is breathing approximately normally and only has the need to breathe oxygenated air. The apparatus can then contain a "breathing goggle" which means a device in the form of a spectacle frame on which small tubes attached, which open inside the nostrils and with an oxygen source connected, which promotes continuously. This oxygen mixes yourself with the inhaled air in your nose. It is about a simple and not very expensive equipment, which is relatively simple is to wear.

In other cases, one agrees to use support of the muscular system, which; Breathing controls. The apparatus may then contain a mask connected to a compressed air source with a relative pressure of the order of 25 mbar (25 × 10 ² Pa) at maximum. This source is equipped with a valve that controls the input of compressed air into the patient's pulmonary system during the inspiratory phase. During the exhalation phase, another valve connects the pulmonary system to the atmosphere. The valve for compressed air is then closed. When the muscular system, in general, is not sufficient, is active during this time, sensors will sense the inhale and exhale phases and control the valves accordingly. When the muscular system is temporarily or finally motionless, a governing organ drives the valves at a rhythm set by the physician.

When to the muscular insufficiency An oxygen accumulation insufficiency can be added Device for mixing the oxygen to the compressed air while provide at least part of the inspiration phase.

Sometimes it is necessary in the course a process of respiratory support even during the Exhalation a certain overpressure in the interior of the lung system, so that the pulmonary alveoli remain in a state of largest opening. The air that leaves the patient's lungs at the moment of exhalation must then z. B. be sent to an enclosed space under the before what is mentioned Pressure, a positive expiratory pressure (pression expiratoire positive), abbreviated P.E.P., is held.

• – eine Leitung, die an einem Ende mit der Atmosphäre und mit einer Druckluftquelle und an einem zweiten Ende mit einer Maske verbunden ist, die geeignet ist, das Lungensystem eines Patienten in Verbindung mit der erwähnten Leitung zu bringen,
• – ein Rückschlagventil, welches in der Leitung so angebracht ist, daß es den Luftdurchgang von dem Patienten zu der Quelle während einer Ausatemphase verhindert,
• – einen Durchgang zur Atmosphäre, welcher an der Maske angebracht ist und fähig ist, das Lungensystem des Patienten mit der Atmosphäre zu verbinden,
• – ein in dem vorher erwähnten Durchgang vorgea sehenes Ventil, das fähig ist, diesen während einer Ausatemphase zu öffnen,
• – wobei das Ventil ein Ventil mir einer elastischen Membran ist, enthaltend eine erste Seite, deren einer Teil dem Eintrittsdruck des Lungensystems des Patienten und der übrige Teil dem Atmosphärendruck unterworfen ist, und eine zweite Membranseite, die pneumatisch mit einem Aufnahmepunkt verbunden ist, welcher in der Leitung oberhalb des Rückschlagventiles liegt,
• – einen Meßfühler, der fähig ist, eine Einatemphase und/oder eine Ausatemphase zu spüren und mit einem Steuerungsmittel verbunden ist und
• – gegenüber McBfühlersignalen empfindliche Steuerungsmittel zum Auslösen der Betätigung oder des Stopps der Luftquelle

A known device for respiratory assistance, z. B. the trade type of the applicant under the name "ARM 25 " , contains:

• A conduit connected at one end to the atmosphere and to a source of pressurized air and at a second end to a mask adapted to bring a patient's pulmonary system into communication with said conduit;
• A check valve which is mounted in the conduit so as to prevent the passage of air from the patient to the source during an exhalation phase,
• A passage to the atmosphere, which is attached to the mask and capable of connecting the patient's pulmonary system to the atmosphere,
• A valve provided in the aforesaid passage and capable of opening it during an exhalation phase,
• The valve being a valve with an elastic membrane, comprising a first side, one part of which is subject to the inlet pressure of the patient 's pulmonary system and the remainder to atmospheric pressure, and a second membrane side, which is pneumatically connected to a receiving point, which in the line is above the check valve,
• A sensor capable of sensing an inhalation phase and / or an exhalation phase and connected to a control means, and
• Control means sensitive to McBus sensor signals for triggering the operation or stopping of the air source

The sensor, which; in the meaning of Passage of compressed air, downstream of the check valve in the pipe is attached, is a Durchflußmengenmeßwertaufnehmer.

At the beginning of an inhalation phase creates the patient a first air mass flow into the line and the Sensor controls then the triggering the operation the compressed air source.

At the end of the inhalation period stops the air mass flow in the pipe. This stoppage is going through taken the probe, which controls the standstill of the compressed air. The pressure of the exhaled air includes then the check valve.

Different means of opening or Conclude of the valve be provided, the opening only at the appropriate overpressure in the case of an operation under P.E.P. takes place.

In some cases, the well-known includes Device the following disadvantage: at the beginning of inhalation before the Durchflußmengenmeßwertaufnehmer feels the first airflow, must the Patient deflate the line and drive the check valve to it in an open position to move. This results, especially in the case of operation under P.E.P., some delay the trigger the operation the compressed air source and also sometimes the effort required by the patient at each Inhaling to be too big.

The invention aims to provide an apparatus which is the fastest possible starting the source of compressed air at each inhalation, and minimizes the efforts made by the patient.

To achieve this goal serves An apparatus according to claim 1. Advantageous embodiments are in the subclaims specified.

To achieve the desired result ro, the invention provides an apparatus of the type described above and in the:

• - of the Probe on across from the pressure on the previously mentioned second surface of the Membrane is acting, sensitive pressure sensor is. The membrane according to the invention Simultaneously ensures two different functions: on the one hand behave she is like a shutter of Valve, which keeps this closed in all cases, with who exercised on her Force, as a result of the difference between the pressures on those two surfaces act, greater than the restoring force the previously mentioned Membrane is and behaves to the other she feels like a pressure transmitter the pressure in the mask to the pressure sensitive sensor.

The pneumatic connected to the membrane Connecting means to connect to the measuring point include necessarily a space, with a wall through the membrane and through a pipeline is formed. A flexible tube of small diameter and an elastic skin attached to one end of this tube can form these connecting means. These also fill a double function off: On the one hand they form by passing the pressure from the pickup point up to the membrane a simple and autonomous control means of the valve. On the other hand, they direct in a direct manner, without an intermediate organ like the check valve, changes the pressure acting on the first surface of the membrane, further.

This results in a very fast reaction of the McBuehler at the beginning of an inhalation. The use of a membrane to feel the beginning of an inhalation has been z. B. in the US-A 4,848,332 but the device described is then connected to costly and complex electronics which are intended to control the valve which is separate from the membrane.

An advantageous embodiment Following, the valve has provided calculated return means to allow that mentioned Valve opens only when simultaneously the pressure at the entrance of the patient's pulmonary system greater than is a previously set positive expiratory pressure and the pressure on the second surface about the membrane equal to the atmospheric pressure is.

Advantageously, the return means of the Membrane for the greatest simplification by its own elasticity the membrane formed.

For the case where the membrane is calculated to open, provided her first surface exposed to a previously set positive expiratory pressure, the probe is preferred able to, to send a signal if the pressure applied to the first surface the membrane of the previously mentioned positive about a lower initial inspiration pressure, but higher than the atmospheric pressure fixed exhalation pressure exceeds.

Furthermore, the effort requested by the patient is maximum reduced, since the reduction caused by the inhalation only part of the positive expiratory pressure is what normally a little bit higher is.

Also preferred is that the pressure sensor is capable of to send a signal of cessation of inhalation when it is on Pickup point one, opposite a predetermined value, higher pressure finds.

This achieves the greatest simplification. On Durchflußmengenmeßwertaufnehmer can be in the line for function control or recording be present of the flow.

While the inhalation phase, the valve is closed and because, due to the Fact of pressure losses in the line of pressure P1 on the first surface across from P2, which acts on the second surface, is lower, the valve remains closed. At the stoppage of inhalation falls the flow stream in the line and the pressures, on the two surfaces act on the membrane, cancel each other. The check valve includes itself, and the pressure P2 on the second surface rises. This pressure increase is through delayed the sensor, the controls the stoppage of the compressed air transmission. The input of the line is located then under atmospheric pressure. The pressure P1 on the first surface is maintained or tends to increase due to exhalation. The Pressure difference between the two surfaces increases to the opening of the Valve, which subsequently as a means of maintaining the intended fixed pressure value is.

The beginning of inhalation pulls one Lowering the pressure acting on the membrane, after itself. This shifts, pulling on a momentary pressure drop the level of the pressure sensor. This then sends out a signal, a restart of the means of production of the compressed air controlling.

The invention will be described in more detail with the help of an embodiment shown, which is illustrated by the accompanying drawings is on which:

The 1 is a theoretical diagram of a breathing apparatus according to the invention,

the 2 and 2A Are graphs that show the pressure and mass flow changes over the course of the respiratory cycles,

the 3 to 5 Sketches are the different positions of the diaphragm valve at un show different stages of the breathing cycle.

The apparatus described by way of example is derived from an apparatus which the Applicant has designated for hospital and commercial use under the name "ARM 25 " is determined.

The respirator contains two parts, the first part 11 being intended for injecting the pulsating air into the respiratory system of the patient P. This first part contains an input A, which is connected to a compressed air source. A pressure regulator 3 , a pressure reducer 4 and a tap for inhalation help 5 allow the pressure built up by the source A to be lowered to an adjustable value which is selected depending on the needs. An electrovalve 6 allows to interrupt the flow arbitrarily in the way and restore that a pulsating process forms. A venturi 7 contains an axial nozzle 8th , which with compressed air from the solenoid valve 6 is supplied, and an inlet for filtered additional air 9 passing through the air, which is the nozzle 8th leaves, if this is supplied, is pulled along. The Venturi 7 is through a lead 10 up to a check valve 11 extended and beyond this by a lead 12 which is directly related to patient P's respiratory system. This line is equipped with a hot wire mass flow sensor 13 fitted. In 14 One has shown a pressure gauge and a pressure sensor downstream of the check valve 11 with the line 10 are connected. The administration 10 flows into the body of a mask in permanent connection with the respiratory system 1 of the patient.

The body of the mask contains an exhalation port 15 , which is connected to the open air, and has a valve 16 provided which is arranged to interrupt its connection to the body of the mask except at Ausatemperioden.

The valve 16 is a diaphragm valve which is formed by an elastic skin or rubber skin, a part of the outer surface of which is subjected to the internal pressure of the mask, while another part of its outer surface is subjected to the atmospheric pressure. The inside of the rubber skin is through a pipe 18 at a measuring point 19 who is in the lead 10 is attached, between the venturi 7 and the check valve 11 connected. A pressure sensor 20 , whose task will be explained later, is at the lead 18 appropriate.

The second part 2 The breathing apparatus is simplified for introducing an oxygen supplement (which may also be another treatment gas) into the respiratory system 1 of the patient. It contains an input B, which is connected to an oxygen source, and a tap 21 for the oxygen dosage in function of the needs. An electrovalve 22 is in a lead 23 interposed, which the cock 21 to the line 10 in the body of the mask so connects that oxygen into the respiratory system 1 the patient is sent

An electronic module of the controller 40 sends control signals on the one hand to the solenoid valve 6 by means of a line 41 and on the other to the solenoid valve 22 through a pipe 32 , which allows a synchronization of the openings of these two solenoid valves.

The module 40 is simultaneous with the means 33 through which it can receive the instructions dependent on the treatment.

The main elements of the first part of the respirator, as well as the control means, are already in the document US-A 5,000,173 again; if only in the device according to the invention are the signals indicating the opening of the electrovalves 14 and 22 trigger and by the DruckmeBfühler 20 over the line 35 to be delivered. A line 34 between the mass flow sensor 13 and the organ 40 can be provided for conveying signals which are intended for storage and / or monitoring of the control processes, without serving for the triggering of the electrovalves.

The 3 to 5 allow the function of the valve 16 to show more clearly. In the 3 one is in an exhalation period and it has been assumed that the valve for a PEP not equal to zero, z. B. 5 hPa, has been regulated. This illustrates that in the line 30 which the valve 16 connects directly to the patient's pulmonary system, while exhaling there is an overpressure P1 of about 5 hPa. This pressure lifts the rubber skin 17 easily from his seat 31 , the air to the exit to the atmosphere 5 allowing it to escape, as indicated by the arrows 32 is indexed. The inside of the rubber skin has the atmospheric pressure due to the pipe 18 is the inside of the rubber skin with the Venturi 7 connected, which is open to the atmosphere, with no mass flow through the injector 8th flows.

The 4 indicates the end of an exhalation period. The pressure in the pipe 30 is now smaller than the atmospheric pressure This results in the rubber skin 17 slightly deformed in order to assist on his seat 31 to come, what the closure of the valve 16 pulls with it. The deformation of the rubber skin pulls a breeze in the line 18 and therefore puts the part of it under negative pressure, which is adjacent to the rubber skin. This negative pressure is of course temporary, but it can be done by the pressure sensor 20 be recorded.

The signals emitted by the probe 20 , are controlled by the module 30 the opening of the solenoid valve 6 triggering and resulting in the initiation of the commissioning of the Venturi. The pressure in the pipe 10 will increase, drawing in the air injection into the pulmonary system of the patient. This pressure, the one Order of magnitude of 18 to 22 hPa, to give an idea, is equally by means of the line 18 to the rubber skin 17 as to the sensor 20 passed. This negative pressure causes a new deformation of the rubber skin, which later on her seat 31 presses and also ensures the waterproofness of the mask to the atmosphere during the entire period of insufflation ventilation.

At the end of this period is the solenoid valve 6 closed and a new exhalation begins in the classical way.

The diagram I in the 2 shows the evolution of mass flow through the mass flow sensor 13 has been included; in the device according to the prior art The diagram II shows the pressure which is in the line 10 through the pressure gauge or the pressure sensor 14 always according to the prior art, and the diagram H1 shows the pressure, which in this case is inside the pipe 18 was recorded by a pressure sensor 20 for the rise.

Diagrams IA, IIA, IIIA, the 2A show the same measurements in the case of a device according to the invention.

Diagrams I, II, III show that, according to the prior art, at time t1, which marks the end of an exhalation period, the patient starts air from the line 10 inhale until time t2, where the pressure on the probe 14 becomes negative what the opening of the check valve 11 with it and the supply of a first positive mass flow d1. This mass flow d1 is through the sensor 12 recorded and triggers the mechanism of the respiratory aid, ie the opening of the solenoid valve 6 and the triggering of the operation of the Venturi 7 which controls the transmission of a much more important mass flow d2 into the patient's respiratory system.

In the course of an inhalation period, the temperature drops through the sensor 12 recorded mass flow due to the progressive filling of the lungs. If the sensor 12 receives that the mass flow has dropped to a predetermined value d3, it sends a signal of completion of the inhalation, which is the closure of the solenoid valve 6 entails and the mass flow drops to zero (time t3).

Diagram II shows that the pressure in the pipe 10 , which is equal to the pressure PEP during the exhalation period, becomes negative at the beginning of Einatemperiode until the time t2, where the opening of the solenoid valve 6 causes a rapid recovery of pressure, well above the PEP

Diagram III shows that the evolution of the pressure in the pipe 18 is similar, with the exception of the fact that during exhalation the line 18 has a pressure of zero, as it interacts with the atmosphere through the venturi 7 connected is.

If you look at the now 2A which shows the mass flow changes and pressure changes with a device according to the invention, it is observed that the time period between the times t1 and t2 is much smaller (the scaling has not been taken into account). In fact, as soon as the probe 20 in the pipe 18 seen a negative pressure p1, seen on the course IIIA, he sends a signal to the beginning of the inhalation, which is the opening of the solenoid valve 6 and the recovery of pressure in the line 12 triggers. The pressure in this line then does not have the time to become negative, as shown in the graph IIA, and the patient demanded power to trigger the process of respiratory assistance during inhalation and comparison with the prior art is considerably reduced. This point is much more important than the reduction of the time interval between times t1 and t2.

Claims (6)

Apparatus for respiratory assistance, comprising: - a conduit ( 12 ) connected at one end to the atmosphere and to a source of pressurized air and at a second end to a mask adapted to bring a patient's pulmonary system into communication with said conduit, - a check valve ( 11 ), which is mounted in the aforementioned conduit so as to prevent the passage of air from the patient to the source of pressurized air during an exhalation phase, a passage to the atmosphere ( 15 ), which is attached to the mask and capable of connecting the patient's pulmonary system to the atmosphere, - a valve ( 16 ), which is provided in said passage, and is adapted to open during an exhalation phase, - wherein the valve ( 16 ) a valve is provided with an elastic membrane ( 17 ) having a first side, a portion of which is subject to the inlet pressure of the patient's pulmonary system and the remainder to atmospheric pressure, and a second diaphragm side which is pneumatically connected to a receiving point located in the conduit above the check valve, a sensor ; which is capable of sensing an inhalation and / or exhalation phase and is connected to a control means, and control means sensitive to MC sensor signals for triggering the actuation or stopping of the air source, characterized in that the sensor is a pressure sensor ( 20 ), which is sensitive to the pressure acting on the second surface of the membrane. Device according to claim 1, characterized in that the valve ( 16 ) has pre-calculated reset means for the aforesaid valve to open only if at the same time the pressure at the inlet of the patient's pulmonary system is higher than a previously positive set exhalation pressure and the pressure on the second surface of the membrane is approximately equal to the atmospheric pressure. Apparatus according to claim 2, characterized in that the return means of the membrane ( 17 ) are formed by the inherent elasticity of the membrane. Apparatus according to claim 2 or 3, characterized in that the pressure sensor ( 20 ) is capable of emitting a signal when the pressure on the first side of the membrane ( 17 ) exceeds said previously presettable exhalation pressure to a lower but higher than atmospheric pressure, inhalation initial pressure. Device according to one of claims 1 to 4, characterized in that the pressure sensor ( 20 ) is capable of emitting a signal of cessation of inspiration when it detects a higher pressure at the pickup point than a predetermined value. Apparatus according to claim 4 or 5, characterized in that it comprises a Durchflußmengenmeßwertaufnehmer ( 13 ) contained in the line, said transducer is connected to means for functional control of the apparatus or for recording.