WO2014012127A2

WO2014012127A2 - Device for generating a pulsating gas columm

Info

Publication number: WO2014012127A2
Application number: PCT/AT2013/000121
Authority: WO
Inventors: Georg SCHINDLER; Robert KÖLBL; Dominik Lirsch
Original assignee: Carl Reiner Gmbh
Priority date: 2012-07-17
Filing date: 2013-07-17
Publication date: 2014-01-23
Also published as: CN104812431A; EP2874685A2; JP2015521952A; WO2014012127A3; CN104812431B

Abstract

On a device for generating a pulsating gas column (4) for the superposed high-frequency jet respiration, a first connection (14) for a low-frequency respiratory gas flow provided by a respiratory device (1), a first jet nozzle (15) associated with the first connection (14), a first venturi body (18) arranged downstream of the first jet nozzle (15), a second connection (20) for a high-frequency respiratory gas flow provided by a respiratory device (1) and a second venturi nozzle (24) arranged downstream of the second jet nozzle (21) are provided, wherein the first venturi body (18) and the second venturi body (24) are associated with a common connection (32) for a respiratory tube.

Description

Device for generating a pulsating gas column

The invention relates to a device for generating a pulsating gas column for superponierte Hochfrequenzj etbe- breathing.

The invention further relates to the use of the device according to the invention in an open or semi-open respiratory system, in particular using a bronchoscope or laryngoscope, wherein the respiratory gas flow provided by a respirator via at least one jet nozzle with additionally aspirated ambient air as a retrograde current via an exspiration into the patient , is introducible.

In high-frequency ventilation, high continuous alveolar distension pressure is built up by using a high gas flow in the ventilation system. The breathing gas is usually administered by jet technique. By the term "jet" is meant the directional administration of a high velocity compressed gas through a nozzle. If the ventilation system is open, so-called Venturi effects occur at the end of the nozzle, which, according to the principle of the water jet pump, increase the volume of breathing gas. In doing so, air that surrounds the jet is dragged along so that the volume of gas that reaches the lungs can be much larger than the amount of gas delivered by the ventilator. The additional gas volume sucked in from the environment is called "entrainment". An integrated into the system oscillator puts the gas flow in pulsating oscillations with a frequency of typically 1-15 hertz. A respirator in which a venturi is located downstream of a jet nozzle to produce a pulsating gas column has become known from DE 3329485 AI.

In superpositioned jet ventilation, two jet ventilation forms with different frequencies are combined. The low-frequency respiratory gas flow is superimposed by a high-frequency respiratory gas flow. The low-frequency component is administered with frequencies up to 40 / min, the superimposed high-frequency component with frequencies between 1 and 15 Hz. It is characteristic of pure high-frequency ventilation that ventilation is not based on the movement of gas volumes through the airways, but rather on the continuous mixing of the respiratory gases at each level in the respiratory system. In superpositioned jet ventilation, this effect of high frequency ventilation is combined with the advantages of conventional low frequency ventilation. The use of two different ventilation frequencies ensures on the one hand, the corresponding base filling during expiration (positive end-expiratory pressure) and thus prevents complete collapse of the lung (high ventilation frequency), and on the other hand allows a corresponding inflation (inspiratory pressure plateau) during inspiration (low ventilation frequency ).

In superpositioned jet ventilation, the respiratory gas is emitted, for example, by means of a T-connector, to the T-bar of which a respiratory gas transverse flow is connected. From EP 823849 AI is. In this connection, a device is known in which transversely to the beam of the T-connector a plurality of tubes with a smaller clear cross-section than the clear cross-section of the transversely to the T-bar subsequent tubular part of the T-connector are arranged, which in the direction extend extending transversely to the T-bar tubular part of the T ~ connector, wherein at least two tubes are acted upon by pulsating compressed gas of different frequency. A disadvantage of this type of jet ventilation, however, is that due to the jet nozzles relatively high shear forces arise, so there is a risk of traumatizing the lungs.

It is an object of the present invention to use the superimposed jet ventilation also during the acute phase in the ARDS (Acute Respiratory Distress Syndrome) or other respiratory episodes, whereby the complete respiration is to be taken over and the lung to be treated gently. The aim is to achieve lower shear forces than under conventional ventilation, as well as the same blood gas values with low inspiratory 0 ₂ concentration (FIO ₂ ) and at. to achieve lower ventilation pressure. Furthermore, the invention aims to ensure a rapid expiration at the end of inspiration without systemic delay.

To achieve this object, the invention provides a device of the aforementioned type, which has a first connection for a low-frequency breathing gas flow provided by a respirator, a first jet nozzle connected to the first connection, a first venturi body arranged downstream of the first jet nozzle, a second A port for a high-frequency breathing gas flow provided by a respirator, a second jet nozzle communicating with the second port, and a second venturi disposed downstream of the second jet nozzle, the first venturi body and the second venturi body communicating with a common port for a breathing tube. Because the low-frequency and the high-frequency breathing Gas flow separately from each other through a respective Venturi body or a Venturi tube, it is possible to produce a low-frequency and a high-frequency oscillating gas column separately from each other. At the same time, due to the separate treatment of the two respiratory gas streams delivered by the ventilator, it is ensured that the ventilator safety functions requiring a separate pressure measurement of the two flows can be used. Thus, for example, in some ventilators a measurement of the residual pressure in the expiratory phase is implemented, wherein the measured values are supplied to a risk analysis and if necessary an alarm signal is generated. If the low-frequency and the high-frequency breathing gas flow were connected to one another and expelled through a common jet nozzle, such an alarm function could not be realized.

Characterized in that the first venturi body and the second venturi body are in communication with a common connection for a breathing tube, the separately generated vibrating gas columns can be connected, so that only a single outlet must be connected to the expiratory limb of a standard tube system.

A preferred development provides that the first and the second jet nozzles each open into a suction chamber in communication with the ambient air in order to entrain ambient air with the jet stream. The entrained at the outlet of the jet stream from a nozzle opening ambient air contributes significantly to ventilation. The total amount of breathing gas from expanded gas and the absorbed respiratory gas together provide the necessary amount of gas for gas exchange. In order to ensure a complete separation of the generation of the low-frequency and the high-frequency gas column, it is preferably provided that the suction chamber associated with the first jet nozzle communicate with the ambient air via a first inspiration opening and the suction chamber associated with the second jet nozzle via a second inspiration opening.

As the etchant gas stream exits the respective venturi, the gas expands and, depending on the conditions, can produce a significant noise level. This noise level is physical and can not be reduced without reducing the efficiency of ventilation. In an advantageous manner, therefore, in each case a silencer is connected to the first and the second inspiration opening. In order to be able to fulfill the relevant hygiene regulations, a preferred embodiment further provides that a filter is in each case connected to the first and the second inspiration opening.

In principle, the expiration can take place via the above-mentioned inspiratory openings. The expired air then flows into the device via the connection for the breathing tube and is conducted there via the first and the second venturi body to the inspiration openings.

Preferably, however, the expiration takes place via a separate outlet of the device. In this context, the device according to the invention is preferably further developed in such a way that an expiration opening is provided which communicates with the connection for the breathing tube. In the case of expiration, the respiratory air is not guided via the first or second venturi body, but rather from the connection for the respiration tube via at least one separate, ie at least partially, section from the one for inspiration. tion provided gas path different line section to the expiration. Advantageously, a filter and possibly a silencer is connected to the expiration opening. A particular advantage is that different filters are used for inspiration and expiration, which significantly improves the hygienic conditions.

In order to be able to realize at least one expiratory valve within the device according to the invention in a simple manner, it is preferably provided that at least one adjustable flap determining the flow cross-section is arranged in the gas path connecting the connection for the breathing tube and the expiration opening. The at least one adjustable flap can be designed so that it is spring-loaded in the opening direction. The flap is thus formed in the manner of a non-return valve, wherein the expiratory flow acts in opening direction and the Inspirationsström in the closing direction on the flap. It is preferred if the at least one flap is designed such that it does not completely occlude the gas path provided for inspiration or expiration, neither in the closed nor in the open state. Rather, it is desirable if the respective gas path, for example, only 90% closed. For this purpose, a preferred embodiment provides that the at least one flap cooperates with an adjustable stop, which determines a minimum flow cross section of the expired air.

In order to ensure in a structurally simple manner that a common connection for a breathing tube can be used for expiration and inspiration, a preferred development provides that an expiratory line having the expiration opening into a second inspiratory line adjoining the second venturi body downstream opens and the second inspiratory line opens into a first inspiratory downstream of the first venturi body. In this case, an adjustable flap can be arranged at each discharge point.

The adjustable flaps are advantageously arranged such that the jet stream coming from the first jet nozzle and the jet flow coming from the second jet nozzle act on the respective adjustable flap in the closing direction.

The invention will be explained in more detail with reference to an embodiment schematically illustrated in the drawing. 1 shows a respiratory system in which the device according to the invention is used, FIG. 2 shows a cross section through the device according to the invention in a first embodiment and FIG. 3 shows a cross section through the device according to the invention in a second embodiment.

1 shows a respirator, for example a TwinStream ™ Multi Mode Respirator of Carl Reiner GmbH. The respirator 1 comprises a low-frequency jet ventilation unit and a high-frequency jet ventilation unit, the low-frequency respiratory gas flow provided by the respirator 1 being delivered via the line 2 and the high-frequency respiratory gas flow via the line 3. The combination of the low-frequency and the high-frequency respiratory gas flow results in a special ventilation pattern, the ventilation being referred to as super-imposed high-frequency jet ventilation. The provided via the lines 2 and 3 breathing gas flow is introduced at high pressure (0.1-3.5 bar) via jet nozzles separately from each other in the device referred to as "jet modifier" 4. The gas stream formed in the jet modifier 4 is in the form of a pulsating gas column via the expiratory tube 5 against a bias flow (breathing gas cross-flow) pressed and therefore introduced the Biasflow in the respiratory passages 6 of the patient. The bias flow is generated by the respirator 1 and provided via the inspiratory tube 7. The Biasflow 8 water vapor is added by means of the gas conditioning unit.

In contrast to conventional ventilation, jet ventilation can be characterized by a simultaneous volumetric flow into the lungs (inspiration) as well as from the lungs (expiration). The high kinetic energy generated by the chopping of the jet stream leads to more frequent collisions between the gas molecules in the alveoli and consequently promotes the diffusion of the 0 ₂ molecules into the blood through the alveolar arm. Due to the continuous gas flow to the outside, the CC> 2 elimination is ensured at the same time.

The bias flow is introduced via the gas conditioning unit 8 into the leg 9 of a Y-piece 10 of a standard hose system. Instead of the Y-piece 10, a measuring adapter can be installed. At the end of the expiratory limb 11, the jet modifier 4 is coupled in as an active expiration valve. The function of the jet modifier 4 is to convert the hard jet jet from the lines 2 and 3 into a well-tolerated flow pattern.

During the expiratory phase of the ventilator 1, the bias flow escapes unhindered over the jet modifier 4 which is seated at the end of the expiratory limb 10. When the respirator 1 switches to the inspiration phase, a countercurrent flow is applied into the expiratory limb 10 by the jet modifier 4 and the result is increased a volume shift and to a adequate pressure build-up in the tube, whereby the respiratory conditioned bias flow is forced into the lungs.

The ventilation pressure can be measured by means of a probe, not shown, and the measured values can be made available to the ventilator 1 for monitoring purposes via a signal line 12.

In Fig. 2, only the jet modifier 4 is shown in detail. The Anschlussbuchse for the provided by the ventilator 1 low-frequency breathing gas flow and the high-frequency breathing gas flow is denoted by 13. The low-frequency respiratory gas flow is discharged via the opening 14 on the inner circumference of the bush 13 and fed to the first jet nozzle 15. The first jet nozzle 15 opens into a suction chamber 16, which communicates with the environment via a radial line and a first inspiration opening 17. A first venturi or venturi 18 immediately adjoins the suction chamber 16, to which in turn the first inspiratory conduit 19 connects.

The high-frequency respiratory gas flow is discharged via the radial bore 20 which opens out on the inner circumference of the bushing 13 and fed to the second jet nozzle 21. The second jet nozzle 21 opens into a suction chamber 22, which communicates with the environment via a radial line and a second inspiration opening 23. A second venturi body or a second venturi tube 24 immediately adjoins the suction chamber 22, to which the second inspiratory line 25 in turn connects. The expiration line 26, which communicates with the environment via the expiration opening 27, opens into the second inspiratory line 25. At the mouth parts of the expiratory line 26, a flap 29 pivotally mounted about the pivot axis 28 is arranged. The second inspiratory line 25 opens into the first inspiratory conduit 19. At the confluence parts of the second inspiratory conduit 25, in turn, a flap 31 mounted pivotably about the pivot axis 30 is arranged. The flaps 29 and 31 are respectively spring-loaded in the direction of opening, wherein the open position of the flaps designates that position in which the gas path connecting the expiration opening 27 and the connection 32 for the breathing tube is maximally opened. The pivoting movement of the flaps 29 and 31 in the closing direction is limited by a stop, not shown, so that the flaps 29 and 31 can not be completely closed. The stop is preferably adjustable, so that the exhalation resistance can be adjusted. When the low-frequency and high-frequency Atemgastroms by the jet nozzles 15 and 21, the ambient air drawn in via the inspiration opening 17 or 23 is entrained at the nozzle exit. The respiratory gas flow is in each case directed via the venturi body 18 or 22 against the flap 29 or 31 and moves the flap depending on the applied pressure during the inspiration phase in the closing direction, so that a flow cross section for the gas to be inspired is increased. The high-frequency current and the low-frequency current are superimposed in the first inspiratory line 19 and discharged into the expiratory tube 5 via the port 32 in the inspiratory phase. In the expiration phase, a quantity of gas passes from the expiratory tube 5 back into the jet modifier 4, where it via the first inspiratory line 19, the open flap 31, the second inspiratory line 25, the flap 29, the expiratory line 26 and the expiratory opening 27 in the Environment is delivered. When exhaling the amount of gas supplied, the bacteria in the lungs and in the respiratory tract are inevitably exhaled and endanger the surgeon and the personnel in the treatment area. Therefore, a filter 33 is connected to the expiratory opening 27 (FIG. 1). Furthermore, a muffler 34 is connected to minimize the noise. A filter 33 and a muffler are also connected to the inspiratory ports 17 and 23. In the alternative embodiment according to FIG. 3, the reference symbols used in FIG. 2 have been retained as far as they are concerned. Components that are used in the embodiment of FIG. 2 are used. The embodiment according to FIG. 3 differs from the embodiment according to FIG. 2 in that the separate expiration opening 27 is dispensed with. The expiratory air thus passes via the connection 32 into the jet modifier 4, where it is forwarded via the inspiratory line 19 and is divided into two partial flows, each via the venturi tube 15 or 15, respectively. 24 and the suction chambers 16 and 22, respectively, to the inspiration openings 17 and 23, respectively. Otherwise the jet modifier according to FIG. 3 functions the same as the jet modifier according to FIG. 2. The embodiment of FIG. 3 allows a particularly compact design.

Claims

Claims :

1. A device for generating a pulsating gas column for superponed high-frequency ventilation comprising a first connection (14) for a low-frequency etching gas flow provided by a ventilator (1), a first jet nozzle (15) connected to the first connection (14) a first venturi body (18) arranged downstream of the first jet nozzle (15), a second connection (20) for a high-frequency respiratory gas flow provided by a ventilator (1), a second jet nozzle (21) connected to the second connection (20) and a second venturi body (24) disposed downstream of the second jet nozzle (21), the first venturi body (18) and the second venturi body (24) communicating with a common port (32) for a breathing tube.

2. Device according to claim 1, characterized in that the first and the second jet nozzle (15, 21) each open into a standing with the ambient air in connection suction chamber (16, 22) to entrain ambient air with the jet stream.

3. A device according to claim 2, characterized in that the first jet nozzle (15) associated with the suction chamber (16) via a first inspiratory opening (17) and the second jet nozzle (21) associated with the suction chamber (22) via a second inspiration opening (23). communicate with the ambient air.

4. Apparatus according to claim 3, characterized in that on the first (17) and the second inspiration opening (23) in each case a filter (33) and optionally a silencer (34) are connected.

5. Device according to one of claims 1 to 4, characterized in that an expiration opening (27) is provided, which communicates with the connection (32) for the breathing tube in connection.

6. Apparatus according to claim 5, characterized in that to the expiration opening (27), a filter (33) and optionally a muffler (34) is connected.

7. Apparatus according to claim 5 or 6, characterized in that in the connection (32) for the breathing tube and the expiration opening (27) connecting the gas path at least one flow cross section defining the adjustable flap (29) is arranged.

8. The device according to claim 7, characterized in that the at least one adjustable flap (29) with a ver ^¬ adjustable stop determines a Mindestdurchfluss- cross-section.

9. Apparatus according to claim 7 or 8, characterized in that the at least one adjustable flap (29) is spring-loaded in the opening direction.

10. Device according to one of claims 5 to 9, characterized in that an expiration opening (27) having expiratory line (26) in a downstream of the second venturi body (24) subsequent second inspiratory line (25) opens and the second inspiratory line (25) in a downstream of the first venturi body (18) subsequent first inspiratory line (19) opens.

11. The device according to claim 10, characterized in that an adjustable flap (29, 31) is arranged at each discharge point.

12. The device according to claim 11, characterized in that the adjustable flaps (29, 31) are arranged such that the of the first jet nozzle (15) coming jet stream and of the second jet nozzle (21) coming jet stream the respective adjustable flap ( 29, 31) acted upon in the closing direction.