GAS FLOW REVERSING ELEMENT WITH BYPASS AND METHOD FOR CONTROLLING EXPIRATION OF A PATIENT

Abstract

A gas flow reversing element is disclosed that includes a main piece comprising an inflow region, a nozzle region and a mixing region, and further includes a branching piece. The inflow region connects a pressure connector to a closable outlet opening in the mixing region, the branching piece connecting the nozzle region to a line connector. With the outlet opening opened, gas flow flowing along a first flow path from the pressure connector through the nozzle to the outlet opening, generates a gas flow in the branching piece flowing along a second flow path from the line connector to the outlet opening. The reversing element further includes a bypass, closable by at least one closing element, connecting the pressure connector and the line connector so that a gas flow can flow along a third flow path via the inflow region, and bypass the nozzle via the bypass.

Claims

1-13. (canceled)

14. A method for controlling expiration of a patient, wherein an expiration phase of ventilation of a patient is being controlled, wherein the method comprises at least the steps of: 1. measuring a pressure value of an expiratory gas flow or expiratory gas volume, wherein the pressure value is a static and/or dynamic pressure value; and 2. regulating the expiratory volumetric gas flow; wherein regulating expiratory volumetric gas flow according to step 2 is conducted based on the measured value of step 1.

15. The method according to claim 14, wherein the expiration is controlled by suction.

16. The method according to claim 14, wherein during an expiratory phase, the expiratory gas flow passes exclusively through a lumen and a ventilation device.

17. The method according to claim 16, wherein the lumen has a small inner diameter of 6 mm or less and/or a cross sectional area of at most 50 mm.sup.2.

18. The method according to claim 14, wherein regulating the expiratory volumetric gas flow achieves a high frequency ventilation of up to at least 100 breaths per minute, and a low flow rate of less than 21/min.

19. The method according to claim 14, wherein the expiratory volumetric gas flow is reduced in the first phase of expiration.

20. The method according to claim 14, wherein regulating the expiratory volumetric gas flow ensures a uniform reduction of the pressure of the expiratory volumetric gas flow and/or of the pressure inside the ventilated part of the lungs of the patient during the expiration phase of ventilation.

21. The method according to claim 14, further comprising repeating steps 1 and step 2 to cause constant monitoring of pressure and constant regulation of the expiratory volumetric gas flow.

22. The method according to claim 14 of the preceding claims, wherein regulating the expiratory volumetric gas flow comprises regulating the expiratory volumetric gas flow with a gas flow reversing element which serves for the use of a gas supply under excess pressure, for selectively generating a gas flow from or to a line connector which is connected to or inserted into an airway of a patient.

23. The method according to claim 22, wherein a patient is ventilated only and completely via the gas flow reversing element, wherein all volumetric gas flows from or to the patient pass through the gas flow reversing element.

Description

[0075] Illustrative embodiments of the invention, which do not however limit the invention, are explained in more detail below with reference to the schematic drawings, in which:

[0076] FIG. 1: shows a longitudinal section through a gas flow reversing element, with peripheral devices indicated;

[0077] FIG. 2: shows the gas flow reversing element in use with gas flowing along the first and second flow paths;

[0078] FIG. 3: shows the gas flow reversing element in use with gas flowing along the third flow path;

[0079] FIG. 4: shows the gas flow reversing element in use with gas flowing along the fourth flow paths;

[0080] FIG. 5: shows the gas flow reversing element with scissor vales as closing elements; and

[0081] FIG. 6: shows the gas flow reversing element of FIG. 5 and a control unit.

[0082] Identical reference numerals in the figures refer to the same devices.

[0083] FIG. 1 shows a longitudinal section through a gas flow reversing element 1 with a main piece 2 which connects a pressure connector 4 to an outlet opening 5. The pressure connector 4 can be connected by a connecting line 13 to a gas supply 14 which is under excess pressure in a compressed gas source 11. A compressed oxygen cylinder is generally made available for the emergency care of patients. Furthermore, complex gas mixtures can be provided as gas supply 14. Extending off from the main piece 2 is a branching piece 3, which leads to a line connector 6. In the main piece 2, an inflow region 9, a flow region 28, a nozzle region 15 with a nozzle 7, and a mixing region 16 with a mixing channel 17 are realized. Inside the nozzle region 15 there is a nozzle 7 through which gas can flow from the pressure connector 4 to the outlet opening 5. This nozzle 7 lies near the branching piece 3, such that the gas flowing through the nozzle 7 to the outlet opening 5 generates an underpressure in the branching piece 3. Here, the principle of a gas jet pump is used. However, it is possible to choose any arrangement that is able to generate a suction effect by means of a gas flow. At least the outlet opening 5 should be able to be closed, for example with a scissor-valve or pinch valve as closing element 19.

[0084] The gas flow reversing element 1 further comprises a bypass 18 connecting the pressure connector 4 and the line connector 6. A gas can therefore flow via the inflow region 9, the bypass 18 and the branching piece 3. At least the bypass 18 and the flow region 28 are closable by at least one closing element 19, so that the gas can bypass the nozzle 7 in the nozzle region 15 via the bypass 18. Here, the at least one closing element 19 is a 3/2-way valve. In the position shown (here referred to as first position) the 3/2-way valve connects the pressure connector 4 and the inflow region 9 with the flow region 28 and the nozzle region 15. The connection to the bypass 18 is closed.

[0085] The branching piece 3 also has a closable side access 12 through which medicine can be added or probes be inserted. Furthermore, a measuring device 25 can be connected with the side access 12 so that certain parameters can be monitored, for example the content of carbon dioxide in expiratory gas.

[0086] Further, the pressure present in the branching piece 3 can be measured with a pressure measuring device 25 via the side access 12.

[0087] Further, the side access 12 can provide as connection for a side port capnometry line. Via this side port capnometry line a small sample of gas can be removed via the side access 12 from the expiratory gas flowing along the second flow path 21 (refer to FIG. 2) for measuring the carbon dioxide concentration. The sample of gas is removed by a use of a suctioning compressor/pump so that the sample is directed into the capnograph (here shown as measuring device 25).

[0088] According to a preferred embodiment the suctioning compressor/pump (here shown as measuring device 25) of the side port capnometry line can be used for deflation of a cuff 24, which is provided to at least partially seal of the airway of a patient and which is positioned on the outside of the lumen 10. The lumen 10 is being connected to the line connector 6 and is being inserted into the airway of the patient. The compressor pump can be connected to the cuff 24 via a separate supply line 29. The supply line 29 can also be arranged inside the gas flow reversing element 1 so that the supply line 29 can also be integrated into the lumen 10, for example into the sidewall of the lumen 10. This arrangement can function as an emergency procedure so that in case of over pressurization of the airway the cuff 24 can be deflated so that gas from the airway of the patient can bypass the lumen 10 and the gas flow reversing element 1.

[0089] Each of the connectors 4, 6 is preferably designed as a Luer lock.

[0090] FIG. 2 shows the gas flow reversing element 1 in use with main piece 2 and branching piece 3. The 3/2-way valve as closing element 19 is in the first position. Thus the inspiratory gas provided by the compressed gas source 11 (not shown) to the gas flow reversing element 1 via the pressure connector 4 flows along the first flow path 20 subsequently through the inflow region 9, the flow region 28, the nozzle region 15 and through the nozzle 7 into the mixing region 16 to the outlet opening 5, with the outlet opening 5 opened. Passing through the nozzle 7 the gas flow 8 flowing along the first flow path 20 generates an underpressure in the nozzle region 15 so that another gas flow 8 is generated in the branching piece 3 flowing along a second flow path 21 from the line connector 6 and subsequently through the branching piece 3, through the nozzle region 15 and through the mixing region 16 to the outlet opening 5.

[0091] FIG. 3 shows the gas flow reversing element 1 in use with main piece 2 and branching piece 3, wherein the 3/2-way valve as closing element 19 is in the second position. In this position the 3/2-way valve connects the pressure connector 4 with the bypass 18. The connection between pressure connector 4 and nozzle region 15 via flow region 28 is disconnected. Thus the inspiratory gas provided by the compressed gas source 11 (not shown) to the gas flow reversing element 1 via the pressure connector 4 flows along the third flow path 22 subsequently through the inflow region 9, through the bypass 18 into the branching piece 3 and to the line connector 6, with the outlet opening 5 being closed. For the third flow path 22, connecting the pressure connector 4 and the line connector 6 via the bypass 18, the gas flow 8 experiences a first pressure loss deltaP1 26 at certain flow rates.

[0092] This first pressure loss deltaP1 26 along the third flow path 22 is much smaller than the second pressure loss delta P2 27 along the fourth flow path 23 for identical volumetric flow rates. Therefore, for a certain pressure provided at the pressure connector 4 by the compressed gas source 11 (not shown) a larger volumetric gas flow rate is achieved along the third flow path 22 than it would be possible along the fourth flow path 23.

[0093] FIG. 4 shows the gas flow reversing element 1 in use with the 3/2-way valve as closing element 19 in the first position. Thus the inspiratory gas provided by the compressed gas source 11 (not shown) to the gas flow reversing element 1 via the pressure connector 4 flows along the fourth flow path 23 subsequently through the inflow region 9, through the nozzle region 15 and through the nozzle 7 into the branching piece 3 and to the line connector 6, with the outlet opening 5 being closed. For the fourth flow path 23, connecting the pressure connector 4 and the line connector 6 via the inflow region 9, the flow region 28, the nozzle region 15, and the branching piece 3, the gas flow experiences a second pressure loss deltaP2 27.

[0094] FIG. 5 shows the gas flow reversing element 1 with scissor valves as closing elements 19. In this case, scissor valves are positioned outside of the gas flow reversing element 1. At least parts of inflow region 9, flow region 28 and bypass 18 are also positioned outside of gas flow reversing element 1. Inflow region 9, flow region 28 and bypass 18 outside of the gas flow reversing element 1 are connected to inflow region 9, flow region 28 and bypass 16 of the gas flow reversing element.

[0095] All closing elements 19 disclosed (scissor valves, 3/2-way valve) can be pneumatically or electronically or manually controlled. In particular, all closing elements 19 are designed to gradually reduce and/or increase the volumetric flow rate along the flow path through the valve.

[0096] FIG. 6 shows the gas flow reversing element 1 of FIG. 5 and a control unit 30. The control unit 30 is for example a fully automated ventilation system to which the gas flow reversing element 1 is connected. In this preferred embodiment scissor valves 19 are integrated into the control unit 30. The gas flow reversing element 1 is connected to the control unit 30 by flow region 30 and bypass 18.

[0097] It is emphasized that gas flow reversing elements 1 of FIGS. 1 to 4 can as well be connected to a control unit 30.

[0098] In any case it is important to measure the pressure inside the lungs of the patient. This is preferably done in two separate ways, for safety reasons (in case one of them fails). Preferably, the lumen 10 (or one of the lumen) connected to the line connector 6 will be connected to a first pressure sensor 31 in a control unit 30 that will measure the lung pressure continuously during ventilation. The connection between pressure sensor 31 and control unit 30 is realized via an extension line 32, which could be a separate line or integrated into the lumen 10 used for ventilation. This is the main pressure measurement, providing medical staff with the data needed.

[0099] Further, there is preferably a separate second pressure sensor 33 in the control unit 30, wherein this second pressure sensor is connected to the inflow region 9 or to the pressure connector 4. This second pressure sensor 33 only measures the pressure when the ventilation is paused. This is because it is fairly impossible to provide for a reliable value of lung pressure through the ventilation lumen (lumen 10, line connector 6, bypass 18 or nozzle region 15 and flow region 28, inflow region 9) when high inspiratory or expiratory flows are running through. In normal mode, this is just a safety feature and it is a check to see if the main pressure measurement (via the first pressure sensor 31) is still working well (first pressure sensor 31 could be broken, but also the lumen 10 connected to the line connector 6 could be obstructed etc.). Therefore, after n numbers of inspiration (n=1 to n=10) and n numbers of expiration, the ventilation is paused for a very short moment (50 to 100 ms [milliseconds]), the gas flow is stopped and a viable pressure measurement can be performed via the ventilation lumen by the second pressure sensor 33.

[0100] Obviously, the gas flow reversing element 1 can be operated with only the first pressure sensor 31 or second pressure sensor 32.

LIST OF REFERENCE NUMERALS

[0101] 1 Gas flow reversing element [0102] 2 Main piece [0103] 3 Branching piece [0104] 4 Pressure connector [0105] 5 Outlet opening [0106] 6 Line connector [0107] 7 Nozzle (injector nozzle) [0108] 8 Gas flow [0109] 9 Inflow region [0110] 10 Lumen [0111] 11 Compressed gas source [0112] 12 Side access [0113] 13 Connecting line [0114] 14 Gas supply [0115] 15 Nozzle region [0116] 16 Mixing region [0117] 17 Mixing channel [0118] 18 Bypass [0119] 19 Closing element [0120] 20 First flow path [0121] 21 Second flow path [0122] 22 Third flow path [0123] 23 Fourth flow path [0124] 24 Cuff [0125] 25 Measuring device [0126] 26 first pressure loss deltaP1 [0127] 27 second pressure loss deltaP2 [0128] 28 flow region [0129] 29 supply line [0130] 30 control unit [0131] 31 first pressure sensor [0132] 32 extension line [0133] 33 second pressure sensor