GAS VALVE FOR VENTILATION, A CIRCUIT FOR A VENTILATION SYSTEM AND A METHOD FOR DETERMINING A RELEASING GAS FLOW

Abstract

The invention discloses a gas valve (11) for ventilation, comprising a main body (12) having a first gas chamber (13), a second gas chamber (15) and at least an inlet duct (14) for supplying a gas to the first gas chamber (13). The gas valve (11) further comprises a proportional valve (24) for temporally sealing the first gas chamber (13) from the second gas chamber (15). The second gas chamber (15) comprises at least a second passage opening (22) for releasing the gas from the second gas chamber (15) and the second gas chamber (15) comprises a port (30) for connecting a pressure measurement apparatus for measuring the gas pressure in the second gas chamber (15). The invention further discloses a circuit with a ventilation limb comprising a gas valve (11) and a method for determining a releasing gas flow of a gas valve.

Claims

1-15. (canceled)

16. A method for determining a released gas flow of a pressure release valve comprising a first gas chamber formed by a first duct and a second duct, a second gas chamber, and a membrane disposed between the first gas chamber and the second gas chamber, the method comprising: pressurizing the membrane to temporarily seal the first gas chamber from the second gas chamber; supplying an inhalation gas to the first gas chamber in a first direction in through the first duct and out through the second duct; supplying an exhalation gas to the first gas chamber in a second direction in through the second duct and out through the first duct; depressurizing the membrane to temporarily unseal the first gas chamber from the second gas chamber; measuring a gas pressure of the exhalation gas in the second gas chamber; and determining the released gas flow based on the measured gas pressure in the second gas chamber.

17. The method of claim 16, wherein pressurizing the membrane to temporarily seal the first gas chamber from the second gas chamber comprises controlling a pressure control port to create a first positive pressure on a first side of the membrane.

18. The method of claim 17, wherein depressurizing the membrane to temporarily unseal the first gas chamber from the second gas chamber comprises releasing the first positive pressure on the first side of the membrane via the pressure control port, and wherein the exhalation gas creates a second positive pressure on a second side of the membrane.

19. The method of claim 18, wherein the second positive pressure on the second side of the membrane lifts at least a portion of the membrane.

20. The method of claim 18, wherein the first side of the membrane faces away from the first gas chamber and the second side of the membrane faces toward the first gas chamber.

21. The method of claim 18, wherein the first gas chamber and the second gas chamber form a main body, and the main body comprises a releasable lid.

22. The method of claim 21, wherein the releasable lid comprises operation limitations configured to reduce an operation path of the membrane between the first positive pressure and the second positive pressure.

23. The method of claim 21, wherein the releasable lid comprises a membrane hinge stabilizer configured to prevent collapse of the membrane due to pressurization.

24. The method of claim 16, wherein measuring the gas pressure comprises measuring the gas pressure via a pressure measurement port leading into the second gas chamber and connected to a pressure measurement apparatus.

25. The method of claim 16, wherein determining the released gas flow comprises determining a differential gas pressure between the measured gas pressure in the second gas chamber and an ambient gas pressure.

26. The method of claim 16, wherein the second gas chamber comprises a first passage opening and a second passage opening vertically separated from the first passage opening, wherein the membrane is disposed on the first passage opening, and wherein determining the released gas flow comprises determining a flow of the exhalation gas as the exhalation gas leaves the second gas chamber via the second passage opening.

27. The method of claim 26, wherein a ratio between a cross-section area of the first passage opening to a cross-section area of the second passage opening is between 0.3 and 0.99.

28. The method of claim 26, wherein the pressure release valve further comprises a third gas chamber having a third passage opening between, and vertically separated from, the first and second passage openings, wherein determining the released gas flow comprises determining a flow of the exhalation gas as the exhalation gas enters the second gas chamber from the third gas chamber and leaves the second gas chamber via the second passage opening.

29. The method of claim 28, wherein a ratio between a cross-section area of the first passage opening to a cross-section area of the second passage opening is between 0.3 and 0.99, and a ratio between a cross-section area of the third passage opening to the cross-section area of the second passage opening is between 0.3 and 0.99.

30. The method of claim 26, wherein the pressure release valve further comprises an adjustment mechanism having a twistable cap configured to adjust a cross-section of the second passage opening.

31. The method of claim 30, wherein the twistable cap comprises a filter media configured to filter the exhalation gas.

32. The method of claim 16, wherein the membrane comprises an operation stabilizer embedded in or connected to the membrane and configured to reduce operational noise.

33. The method of claim 16, wherein the membrane comprises a flexible rubber material or a plastic material with flexible hinges.

34. The method of claim 16, wherein the second gas chamber is connected to a carbon dioxide indicator configured to measure carbon dioxide during exhalation.

35. The method of claim 16, wherein the first gas chamber is at least partially surrounded by the second gas chamber.

Description

[0067] Further advantageous aspects of the invention are explained in the following by means of exemplary embodiments and the figures. In the drawings, it is shown in a schematic manner. Furthermore, a numeric counting within this application is just used to differ between said parts of said gas valve.

[0068] FIG. 1: A first embodiment of a gas valve in a perspective view,

[0069] FIG. 2: individual part of said gas valve of FIG. 1 in an exploded-view,

[0070] FIG. 3: said gas valve of FIG. 1 in a first cutaway view,

[0071] FIG. 4: said gas valve of FIG. 1 in a second cutaway view,

[0072] FIG. 5: parts of said gas valve of FIG. 1 in a third cutaway view,

[0073] FIG. 6: said gas valve of FIG. 1 in a cross-section view,

[0074] FIG. 7: a further embodiment of said gas valve of FIG. 1 an exploded-view

[0075] FIG. 8: a circuit comprising at least a gas valve of the previous mentioned Figures in a schematic view, and

[0076] FIG. 9: an assembly with said gas valve of FIG. 1 in a perspective view.

[0077] FIG. 1 to FIG. 3 shows a first embodiment of a gas valve 11 comprising a main body 12 having a first gas chamber 13, a second gas chamber 15, an inlet duct 14 for supplying a gas to the first gas chamber 13 and an outlet duct 16 for releasing the gas from the first gas chamber 13. Said inlet duct 14 and said outlet duct 16 form said first gas chamber 13 within the main body 12. The first gas chamber 13 and the second gas chamber 15 are connected by an intermediate gas chamber 17 and a first passage opening 19. Said second gas chamber 15, which is placed within said main body 12, comprises a port 30 for connecting a pressure measurement apparatus for measuring the gas pressure in the second gas chamber 15. Furthermore, said second gas chamber 15 comprises a second passage opening 22 for releasing the gas from the second gas chamber 15 to the ambient environment.

[0078] Said first gas chamber 13 and said second gas chamber 15 are arranged in said main body 12, while said first gas chamber 13 is at least partially surrounded by the second gas chamber 15. The compact arrangement supports the pressure measurement in the said second gas chamber 15 due to a short measurement path within said gas valve 11. This preferred embodiment of said gas valve 11 comprises said intermediate gas chamber 17, which is arranged between the first gas chamber 13 and the second gas chamber 15. Said intermediate gas chamber 17 comprises said first passage opening 19 and a third passage opening 20. The first passage opening 19 and the second passage opening 22 as well as the third passage opening 20 are vertically separated within the assembled gas valve 11.

[0079] The first passage opening 19 comprises a larger cross-section area compared to the cross-section area of the third passage opening 20. Said third passage opening 20 comprises a smaller cross-section area compared to the cross-section area of the second passage opening 22. The ratio of the cross-section area of the third passage opening 20 and the cross-section area of the second passage opening 22 is about 0.69, which leads to a stable valve characteristic and an optimized characteristic slope of the gas pressure characteristic during the gas pressure measurement.

[0080] In addition, said gas valve 11 comprises a releasable lid 31 and releasable cap 41 and therefore comprises three main parts (main body 12, lid 31 and cap 41), which can be separated from each other (see FIG. 2). Said three main parts are made of plastic most properly produced by an injection moulding method. FIG. 1 shows said gas valve 11 in an assembled condition, while FIG. 2 shows the individual parts of said gas valve 11.

[0081] In an alternative embodiment of said gas valve 11, said intermediate gas chamber can be omitted (not shown). The remaining parts of the above-mentioned gas valve 11 are unchanged. Such an embodiment of said gas valve comprises just one passage opening (as a first passage opening) for above-mentioned first passage opening and said third passage opening, which is arranged between a first gas chamber and a second gas chamber. The ratio of the cross-section area of first passage opening and the cross-section area of the second passage opening can be also 0.69.

[0082] FIGS. 4 and 5 show the above-mentioned gas valve 11 comprising a membrane 25 as a proportional valve 24 for temporarily sealing the first gas chamber 13 from the second gas chamber 15. Said membrane 25 is made of a flexible material like a rubber material or a plastic material with flexible hinges 26. Said membrane 25 is assembled on said first passage opening 19 to control the gas flow through said first passage opening 19 during an exhalation process. Said membrane 25 comprises an operation stabilizer 27 for reducing an operational noise. Said stabilizer 27 comprises an additional mass element, embedded or connected to said membrane 25, which avoids a formation of a resonance frequency during operation. Said membrane 25 is replaceable in the assembly of said gas valve 11. Therefore, membrane 25 with different operation stabilizers 27 can be used within said gas valve 11.

[0083] The gas valve 11 comprises a membrane control mechanism 28 for controlling the membrane operation configuration between an inactive operation and an active operation. Said membrane control mechanism 28 is a pneumatic mechanism comprising a pressure control port 29. Said pressure control port 29 can be connected to a control apparatus, like a ventilator apparatus, which controls the membrane operation configuration by pressurizing said membrane 25 from one side. Said pressure control port 29 can be connected to said control apparatus by a pressure pipe/tube (see FIG. 8 and FIG. 9). Said membrane 25 seals said first passage opening 19 by pressurizing the membrane 25 with a positive pressure threshold via said pressure control port 29. While pressurizing, said membrane 25 is activated (active operation). Otherwise said membrane 25 is inactive and can be lifted by a positive pressure in said first gas chamber 13 during an exhalation process (inactive operation).

[0084] FIG. 5 shows said releasable lid 31, which comprises membrane operation limitations 33 and a membrane hinge stabilizer 32. Said operation limitations 33 reduces the operation path of said membrane 25 between said inactive operation and said active operation configuration. Said operation limitations 33 are bars, which are placed at an inner side of said releasable lid 31. In addition, said membrane hinge stabilizer 32 prevents a collapse of said membrane 25 caused by an undesired pressure direction on the membrane 25. Said membrane hinge stabilizer 32 comprises a bar, which is arranged at said inner side of said lid 31 and essentially at the edge of said lid 31. Said bar essentially sticks into the direction of said operation stabilizers 27 of said membrane 25, if said lid 31 is assembled on said main body 12.

[0085] FIG. 6 shows a cross-section view of the above-mentioned assembled gas valve 11 for ventilation to further disclose said second gas chamber 15. Said port 30 for connecting a pressure measurement apparatus for measuring the gas pressure in the second gas chamber 15 is arranged at said second gas chamber 15, off the main gas flow 23 through said second gas chamber 15. Said main gas flow 23 centrally extends from the first passage opening 19, through the second gas chamber 15 to the second passage opening 22. Said second gas chamber 15 comprises a dividing element 37 for stabilizing the pressure measurement in the second gas chamber 15. Said dividing element 37 is arranged adjacent to said main gas flow 23 in said second gas chamber 15. Said dividing element 37 can also be used as a guiding element for guiding the gas along the second gas chamber 15 to the second passage opening 22. Said dividing element 37 comprises at least a rib 38. Said rib 38 can be exchangeable within the assembly of said second gas chamber 15. Said dividing element 37 can at least partially consist of a filter 39. The gas valve 11 comprises a releasable cap 41 for closing at least the second gas chamber 15. By releasing said cap 41 from said main body 12, a direct access to said second gas chamber 15 is provided. Said cap 41 comprises the second passage opening 22 and a protection means 45 for protecting the second passage opening 22 at least partially from clogging. In addition, said releasable cap 41 comprises cap openings 47 for releasing said gas flow from the second gas chamber 15. Said second passage opening 22 is arranged off said centre of said cap 41. Therefore, said second passage opening 22 is arranged asymmetric to said main gas flow 23 through said second gas chamber 15.

[0086] The gas valve 11 furthermore can comprise a filter media 50 for filtering the gas in the second gas chamber 15 within the main body 12. Said filter media 50 can be assembled in the releasable cap 41 (not shown). Alternatively, said filter media 50 is assembled in the inlet duct 14 of said main body 12.

[0087] FIG. 1 to FIG. 6 are in addition used to disclose a method for determining a releasing gas flow from said gas valve 11. During inhalation, an inhalation gas is supplied to the first gas chamber 13 through said inlet duct 14 and said outlet duct 15 in a first direction. Said membrane 25, as a proportional valve, is in an active operation configuration due to said pressurization of said membrane 25 by a threshold pressure from one side via said pressure control port 29. Afterwards, during exhalation, an exhalation gas is supplied to the first gas chamber 13 through said outlet duct 16 in a second direction. Said first direction is essentially inverse to said second direction. In addition, said membrane 25 is in an inactive operation configuration, while no threshold pressure via said pressure control port 29 is applied to said membrane 25. Said exhalation gas opens at least the first passage opening 19 between said first gas chamber 13 and said second gas chamber 15 by lifting said membrane 25 with the positive exhalation pressure. Said exhalation gas flows, as main gas flow 23, through said second chamber 15 to said second passage opening 22 comprising a certain gas pressure. Said gas pressure is measured in the second gas chamber 15 with a pressure measurement apparatus, which is connected via said port 30 and a pressure pipe/tube 102 to said second gas chamber 15 (see FIG. 8 or FIG. 9). Said pressure measurement apparatus comprises a control unit, e.g. a processor (not shown) to determine said releasing gas flow based on said measured gas pressure in said second gas chamber 15. For example, said releasing gas flow is determined by a differential gas pressure measurement, with at least a first gas pressure in said second gas chamber 15, measured via said port 30 of said gas valve 11, and at least an ambient gas pressure as a second gas pressure.

[0088] FIG. 7 shows a further embodiment of the above-mentioned gas valve 11, additionally comprising an adjustment mechanism 60 for adjusting the effective cross-section of said second passage opening 22. Said adjustment mechanism 60 comprises a cap 61 with cap openings 67, which can be assembled to the main body 12 of said gas valve 11. Said cap 61 is twistable around the central longitudinal axes of said main body 12 of said gas valve 11 and comprises a control opening 63 for adjusting the effective cross-section area of said second passage opening 22. Therefore, said abovementioned ratio of said cross-section areas are adjustable. Said cap 61 may additionally comprise said filter media 50 for filtering the gas and for damping the noise during operation. Said filter media 50 may consist of a foam material. The above-mentioned parts of said gas valve 11 remain unchanged (see FIG. 1 to FIG. 6).

[0089] FIG. 8 shows a circuit 70 for a ventilation system 100 comprising a ventilation limb 71 and at least a gas valve 11 to any of the above-mentioned embodiments. Said gas valve 11 is assembled at the distal end 72 of the ventilation limb 71 with said outlet duct 16 and is used as a pressure release valve. Said circuit 70 is connected via said inlet duct 14 of said gas valve 11 to said ventilator apparatus 101. Said inlet duct 14 can comprise an above-mentioned filter media. Therefore, the above-mentioned port for connecting a pressure measurement apparatus 105 for measuring the gas pressure and/or said pressure control port 29 of said gas valve 11 are connected to the ventilator apparatus 101 via said pressure pipes/tubes 102 and 103. A carbon dioxide measurement 75 is assembled to said circuit 70, which is a colorimetric carbon dioxide indicator 78, assembled at said gas valve 11. Said colorimetric carbon dioxide indicator 78 is a strip and consists of a paper or thin chemical substrate which changes colour depending upon the carbon dioxide threshold within the breathing gas in said gas valve 11. Alternatively, said indicator may consist of a grid and/or comprises a carbon dioxide scale. In addition to the above-mentioned method for determining said releasing gas flow from said second gas chamber 15, the carbon dioxide is measured in the second gas chamber 15 of said gas valve 11 during exhalation.

[0090] In addition, a further leakage 76 is placed at the proximal end 73 of the ventilation limb 71. Said proximal end 73 of the ventilation limb 71 is connected to a respiration mask 108.

[0091] During an inhalation process, an inhalation gas will pass the pressure release valve through said inlet duct 14 and outlet duct 16 and afterwards will reach via said ventilation limb 71 a patient. During an exhalation process, an exhalation gas will leave said ventilation limb 71 through said further leakage 76 and will not contaminate said pressure release valve. Nevertheless, part of said exhalation gas will pressurize the remaining gas in the ventilation limb 71 during said exhalation process, which is measured in the gas valve 11 for measuring said gas pressure and calculating said release gas flow in said second gas chamber 15.

[0092] FIG. 9 shows an assembly 80 with said gas valve 11, according to one of the above-mentioned embodiments (FIG. 1 to FIG. 6 or FIG. 7). The assembly 80 comprises the above-mentioned pressure pipes/tubes 102 and 103, which are connected to the above-mentioned pressure control port 29 and port 30.

LIST OF REFERENCES

[0093] 11 gas valve [0094] 12 main body of 13 [0095] 13 first gas chamber [0096] 14 inlet duct [0097] 15 second gas chamber [0098] 16 outlet duct [0099] 17 intermediate gas chamber [0100] 19 first passage opening [0101] 20 third passage opening [0102] 22 second passage opening [0103] 23 main gas flow through 15 [0104] 24 proportional valve [0105] 25 membrane [0106] 26 flexible hinges of 25 [0107] 27 operation stabilizer [0108] 28 membrane control mechanism [0109] 29 pressure control port [0110] 30 port [0111] 31 lid [0112] 32 membrane hinge stabilizer [0113] 33 membrane operation limitations [0114] 37 dividing element [0115] 38 rib [0116] 39 filter [0117] 41 cap [0118] 45 protection means [0119] 47 cap opening of 41 [0120] 50 filter media [0121] 60 adjustment mechanism [0122] 61 cap [0123] 63 control opening [0124] 67 cap openings of 61 [0125] 70 circuit [0126] 71 ventilation limb [0127] 72 distal end of 71 [0128] 73 proximal end 71 [0129] 75 carbon dioxide measurement [0130] 76 leakage [0131] 78 colorimetric carbon dioxide indicator [0132] 80 assembly [0133] 100 ventilation system [0134] 101 ventilator apparatus [0135] 102 pressure pipe/tubes [0136] 103 pressure pipe/tubes [0137] 105 pressure measurement apparatus [0138] 108 respiration mask