Exhalation valve for a ventilator apparatus with a valve configuration for reducing noise emission

Abstract

An exhalation valve for a ventilator apparatus for at least partial instrumental respiratory assistance of a patient, includes a valve housing with a flow passage which extends along a passage trajectory defining a local axial, radial and circumferential direction and along which respiratory air can flow through the valve housing. The valve housing has a housing-side valve sub-formation with a closed end surface which extends around the passage trajectory and towards which a mating surface of a valve body, movable relative to the valve housing and facing the end surface, can be pretensioned by the pretensioning force of a pretensioning device in such a way that the mating surface, when subjected to respiratory gas in an exhalation flow direction counter to the pretensioning force of the pretensioning device, is removable.

Claims

1. An exhalation valve for a ventilation apparatus for at least partly mechanically assisted ventilation of a patient, comprising: a valve housing having a flow passage which extends along a passage path that defines a local axial, radial, and circumferential direction, and along which respiratory air can flow through the valve housing, the valve housing comprising a housing-mounted valve sub-configuration having an end surface which continuously encircles the passage path; and a counterpart surface, facing toward the end surface, of a valve body movable relative to the valve housing being preloaded by a preloading device in such a way that as a result of impingement of a flow of respiratory gas in an exhalation flow direction, the counterpart surface is movable away from the end surface in a lifting direction against a preload force of the preloading device, accompanied by enlargement of an annular gap generatable or present between the end surface and the counterpart surface, so that the flow passage is flowthrough-capable in the exhalation flow direction and so that a flow through the flow passage in a flow direction opposite to the exhalation flow direction is blockable by abutment of the counterpart surface of the valve body against the end surface; wherein the valve body comprises a skirt which, when considering the exhalation valve in a reference state not stressed by a respiratory flow as intended, extends in a circumferential direction surrounding the counterpart surface and the end surface, and which in the reference state projects axially beyond the end surface, oppositely to the lifting direction, in a direction away from the counterpart surface, an annular gap space being provided radially between the skirt and an end portion, facing toward the end surface, of the valve sub-configuration; wherein a magnitude of a spacing, to be measured parallel to the lifting direction, between a skirt rim remote from the counterpart surface and the counterpart surface is different at least circumferentially locally depending on the respective position in a circumferential direction.

2. The exhalation valve according to claim 1, wherein the skirt rim remote from the counterpart surface exhibits a wave shape proceeding in a circumferential direction.

3. The exhalation valve according to claim 2, wherein the wave shape has a triangular and/or rectangular and/or partial-circle wave shape and/or a sinusoidal wave shape.

4. The exhalation valve according to claim 2, wherein at least some of the extreme points of the wave crests located farthest from the counterpart surface oppositely to the lifting direction, and/or at least some of the extreme points of the wave troughs located closest to the counterpart surface oppositely to the lifting direction, are located on one plane.

5. The exhalation valve according to claim 1, wherein the counterpart surface and/or the end surface is/are located in one plane.

6. The exhalation valve according to claim 1, wherein the end surface is located at a longitudinal end of a tubular portion of the flow passage constituting the end portion of the valve sub-configuration; the skirt surrounding, in the reference state, an end region, extending along the passage path and in a circumferential direction around it, of the tubular portion.

7. The exhalation valve according to claim 6, wherein a radially outer region of the longitudinal end of the tubular portion is beveled, the skirt extending, in the reference state, oppositely to the lifting direction beyond the bevel end located axially farther from the end surface.

8. The exhalation valve according to claim 7, wherein in the reference state, the radial spacing between the bevel end located closer to the end surface and a radially inward-facing wall of the skirt, and the overlap depth of the skirt and the tubular portion parallel to the lifting direction, differ by no more than 20%.

9. The exhalation valve according to claim 1, wherein in the reference state, the radial dimension of the annular gap space and the radial thickness of the skirt differ, in an end region of the skirt containing the skirt rim located remotely from the counterpart surface, by no more than 20%.

10. The exhalation valve according to claim 1, wherein a part of the flow passage is constituted by a respiration tube and by an annular channel surrounding the respiration tube, the annular gap between the end surface and counterpart surface being constituted in terms of flow mechanics between the respiration tube and the annular channel in the exhalation flow direction.

11. The exhalation valve according to claim 1, wherein the valve body comprises a substantially flat plate portion which comprises the counterpart surface and which connects to a fastening portion radially externally surrounding the plate portion.

12. The exhalation valve according to claim 11, wherein the plate portion is reinforced by a reinforcing component comprising a metal disk and/or a ceramic disk, the reinforcing component being exposed at least in portions on that side of the plate portion which faces away from the end surface.

13. The exhalation valve according to claim 1, wherein the preloading device preloads the counterpart surface, in a plane orthogonal to the lifting direction, into a predetermined idle position, in particular centers it relative to the passage path in the region of the counterpart surface, and/or guides it during a lifting and return motion respectively in and oppositely to the lifting direction.

14. The exhalation valve according to claim 1, wherein an actuator, a positioning member of which interacts with the valve body at least in order to displace the counterpart surface oppositely to the lifting direction, is connected to the valve housing.

15. The exhalation valve according to claim 14, wherein the positioning member of the actuator is coupled or couplable to the valve body for displacement of the counterpart surface both in and oppositely to the lifting direction.

16. The ventilation apparatus for at least partly mechanically assisted ventilation of the patient of claim 1, comprising: a respiratory gas conveying pump, the exhalation valve according to claim 1, and an inhalation valve.

17. The valve body for the exhalation valve of claim 1, said valve body encompassing an abutment surface of the counterpart surface that is embodied for abutment against a valve seat surface of the end surface and is movable along a motion axis in and oppositely to the lifting direction; the abutment surface enclosing an angle with the motion axis; the valve body comprising the skirt which surrounds the abutment surface radially externally with reference to the motion axis and which, proceeding from a valve body portion comprising the abutment surface, protrudes from the valve body portion axially with reference to the motion axis and in that context projects axially beyond the abutment surface.

18. The exhalation valve according to claim 2, wherein all of the extreme points of the wave crests located farthest from the counterpart surface oppositely to the lifting direction, and/or all of the extreme points of the wave troughs located closest to the counterpart surface oppositely to the lifting direction, are located on one plane.

19. The exhalation valve according to claim 1, wherein the counterpart surface and/or the end surface is/are flat.

20. The exhalation valve according to claim 2, wherein at least some of the extreme points of the wave crests located farthest from the counterpart surface oppositely to the lifting direction, and/or at least some of the extreme points of the wave troughs located closest to the counterpart surface oppositely to the lifting direction, are located on a plane that is orthogonal to the course of the passage path at the penetration point of the plane and/or orthogonal to the lifting direction.

21. The exhalation valve according to claim 7, wherein in the reference state, the radial spacing between the bevel end located closer to the end surface and a radially inward-facing wall of the skirt, and the overlap depth of the skirt and the tubular portion parallel to the lifting direction, differ by no more than 10%.

22. The exhalation valve according to claim 1, wherein in the reference state, the radial dimension of the annular gap space and the radial thickness of the skirt differ, in an end region of the skirt containing the skirt rim located remotely from the counterpart surface, by no more than 10%.

23. The exhalation valve according to claim 1, wherein a part of the flow passage is constituted by a respiration tube and by an annular channel surrounding the respiration tube coaxially, the annular gap between the end surface and counterpart surface being constituted in terms of flow mechanics between the respiration tube and the annular channel in the exhalation flow direction.

24. The exhalation valve according to claim 1, wherein the valve body comprises a substantially flat plate portion which comprises the counterpart surface and which connects, by means of a diaphragm spring constituting the preloading device, to a fastening portion radially externally surrounding the plate portion.

25. The exhalation valve according to claim 7, wherein in the reference state, the radial spacing between the bevel end located closer to the end surface and a radially inward-facing wall of the skirt, and the overlap depth of the skirt and the tubular portion parallel to the lifting direction, are identical.

26. The exhalation valve according to claim 1, wherein in the reference state, the radial dimension of the annular gap space and the radial thickness of the skirt are identical in an end region of the skirt containing the skirt rim located remotely from the counterpart surface.

27. The valve body for the exhalation valve of claim 1, encompassing an abutment surface of the counterpart surface that is embodied for abutment against a valve seat surface of the end surface and is movable along a motion axis in and oppositely to the lifting direction; the abutment surface enclosing a right angle with the motion axis; the valve body comprising the skirt which surrounds the abutment surface radially externally with reference to the motion axis and which, proceeding from a valve body portion comprising the abutment surface, protrudes from the valve body portion axially with reference to the motion axis and in that context projects axially beyond the abutment surface.

28. An exhalation valve for a ventilation apparatus for at least partly mechanically assisted ventilation of a patient, comprising: a valve housing having a flow passage which extends along a passage path that defines a local axial, radial, and circumferential direction, and along which respiratory air can flow through the valve housing, the valve housing comprising a housing-mounted valve sub-configuration having an end surface which continuously encircles the passage path; and a counterpart surface, facing toward the end surface, of a valve body movable relative to the valve housing being preloaded by a preloading device in such a way that as a result of impingement of a flow of respiratory gas in an exhalation flow direction, the counterpart surface is movable away from the end surface in a lifting direction against a preload force of the preloading device, accompanied by enlargement of an annular gap generatable or present between the end surface and the counterpart surface, so that the flow passage is flowthrough-capable in the exhalation flow direction and so that a flow through the flow passage in a flow direction opposite to the exhalation flow direction is blockable by abutment of the counterpart surface of the valve body against the end surface; wherein the valve body comprises a skirt which, when considering the exhalation valve in a reference state not stressed by a respiratory flow as intended, extends in a circumferential direction surrounding the counterpart surface and the end surface, and which in the reference state projects axially beyond the end surface, oppositely to the lifting direction, in a direction away from the counterpart surface, an annular gap space being provided radially between the skirt and an end portion, facing toward the end surface, of the valve sub-configuration; and wherein in the reference state, the radial dimension of the annular gap space and the radial thickness of the skirt differ, in an end region of the skirt containing a skirt rim located remotely from the counterpart surface, by no more than 20%.

29. An exhalation valve for a ventilation apparatus for at least partly mechanically assisted ventilation of a patient, comprising: a valve housing having a flow passage which extends along a passage path that defines a local axial, radial, and circumferential direction, and along which respiratory air can flow through the valve housing, the valve housing comprising a housing-mounted valve sub-configuration having an end surface which continuously encircles the passage path; and a counterpart surface, facing toward the end surface, of a valve body movable relative to the valve housing being preloaded by a preloading device in such a way that as a result of impingement of a flow of respiratory gas in an exhalation flow direction, the counterpart surface is movable away from the end surface in a lifting direction against a preload force of the preloading device, accompanied by enlargement of an annular gap generatable or present between the end surface and the counterpart surface, so that the flow passage is flowthrough-capable in the exhalation flow direction and so that a flow through the flow passage in a flow direction opposite to the exhalation flow direction is blockable by abutment of the counterpart surface of the valve body against the end surface; wherein the valve body comprises a skirt which, when considering the exhalation valve in a reference state not stressed by a respiratory flow as intended, extends in a circumferential direction surrounding the counterpart surface and the end surface, and which in the reference state projects axially beyond the end surface, oppositely to the lifting direction, in a direction away from the counterpart surface, an annular gap space being provided radially between the skirt and an end portion, facing toward the end surface, of the valve sub-configuration; wherein the valve body comprises a substantially flat plate portion which comprises the counterpart surface and which connects to a fastening portion radially externally surrounding the plate portion; and wherein the plate portion is reinforced by a reinforcing component comprising a metal disk and/or a ceramic disk, the reinforcing component being exposed at least in portions on that side of the plate portion which faces away from the end surface.

Description

(1) The present invention will be presented in further detail below with reference to the appended drawings, in which:

(2) FIG. 1 is a longitudinal section view of an exhalation valve according to the present invention of the present Application;

(3) FIG. 2 is a longitudinally section perspective view of the exhalation valve of FIG. 1;

(4) FIG. 3 is a longitudinal section view through the valve body of the exhalation valve of FIGS. 1 and 2, which is also of itself a valve body according to the present invention;

(5) FIG. 4 is a detail view of portion IV of FIG. 3;

(6) FIG. 5 is a detail view of portion V of FIG. 1;

(7) FIG. 6 is an elevation view of the valve body of the exhalation valve of FIG. 2;

(8) FIG. 7 shows a first alternative configuration of the exposed skirt rim;

(9) FIG. 8 shows second alternative configuration of the exposed skirt rim; and

(10) FIG. 9 is a block diagram of a ventilation apparatus having the exhalation valve of the present invention.

(11) In FIG. 1, an embodiment according to the present invention of an exhalation valve of the present Application is labeled in general with the number 10 and depicted in longitudinal section. The section plane contains passage path D, which in the embodiment shown comprises two portions, namely portion D1 upstream of a valve body 12, and portion D2 downstream from valve body 12, in exhalation flow direction E.

(12) Valve body 12 is retained on a valve housing 14 that is preferably manufactured integrally, for example using the injection molding method.

(13) A flow passage 16, which extends along passage path portions D1 and D2, is embodied in the valve housing or housing 14.

(14) Housing 14 comprises a respiration tube 18, embodied integrally thereon, which proceeds in a straight line along passage path portion D1, widening locally in exhalation flow direction E toward valve body 12. Passage path portion D1 therefore coincides with tube axis R of respiration tube 18. Respiration tube 18 thus constitutes an upstream flow passage portion 20 of flow passage 16. Embodied at an end portion 22 of respiration tube 18 located closest to valve body 12 is an end surface 24 at the end of respiration tube 18 encircling flow passage 16 in that region, which surface is located oppositely from a counterpart surface 26 of a plate-like portion 28, embodied to be substantially flat, of valve body 12.

(15) In the reference state depicted in the Figures, counterpart surface 26 is located at a small gap distance from end surface 24. As soon as a patient connected to proximal end 30 of exhalation valve 10 inhales, however, the pressure difference thereby produced at valve body 12 would cause the latter to move toward end surface 24 until counterpart surface 26 sits on end surface 24, so that flow passage 16 is then blocked for flow through it in a direction opposite to exhalation direction E. Alternatively to what is depicted in FIGS. 1, 2, and 5, valve body 12 can already, in the reference state unstressed by a respiratory gas flow of a patient, sit with counterpart surface 26 on end surface 24.

(16) The downstream part of flow passage 16, i.e. the portion located behind valve body 12 in terms of flow mechanics in exhalation flow direction E, is constituted from two sub-portions: A first downstream portion 32, located closer to valve body 12, of flow passage 16 is embodied as an annular channel concentrically with end portion 22 of respiration tube 18 and thus concentrically with upstream portion 20 of flow passage 16. The annular channel of portion 32 surrounds the upstream portion of flow passage 16 radially externally with reference to passage path portion D1, which is the passage path portion both for upstream portion 20 and for downstream portion 32, located closer to valve body 12, of flow passage 16.

(17) Flow passage 16 encompasses a stub conduit 36, leading toward distal end 34 of exhalation valve 10, which emerges orthogonally from annular channel 32 or from portion 32 of flow passage 16 which forms the annular channel and is located closer to valve body 12. Portions D1 and D2 of the passage path are arranged orthogonally to one another in FIGS. 1 and 2, and intersect if portion D2 is notionally prolonged. This is merely a preferred arrangement, however. Depending on the space circumstances available in a ventilation apparatus that receives exhalation valve 10, portions D1 and D2 can be askew, i.e. can not intersect one another, and/or can also enclose between one another angles other than the right angle shown in FIG. 1.

(18) Plate-like portion 28 of valve body 12, which comprises counterpart surface 26, is embodied to be substantially flat and oriented orthogonally to passage path portion D1. Passage path portion D1 furthermore forms, or coincides with, a body axis K that passes centrally through valve body 12 substantially as a rotational symmetry axis.

(19) Plate-like portion 28 having counterpart surface 26 embodied thereon is connected, via a diaphragm spring 38 proceeding completely around body axis K or flow passage portion D1, to a fastening portion 40 embodied radially outside plate portion 28.

(20) Fastening portion 40 is connected in positively engaging fashion, in a manner known per se, to a portion of valve housing 14. Valve body 12 in its entirety is retained on valve housing 14 by fastening portion 40. Diaphragm spring 38 centers plate-like portion 28 relative to respiration tube 18 and preloads plate-like portion 28 toward end surface 24, or presents a resistance that opposes lifting of plate-like portion 28, or of counterpart surface 26 provided thereon, away from end surface 24. Preferably, the farther counterpart surface 26 is from end surface 24 along first flow passage portion D1 in lifting direction A, the greater the resistance. In the exemplifying embodiment described here, lifting direction A proceeds along first portion D1 of the passage path.

(21) During an exhalation event of a patient connected to proximal end 30 of exhalation valve 10, the pressure in upstream portion 20 of flow passage 16 becomes elevated while ambient pressure is constantly present on that side of valve body 12 which faces away from respiration tube 18. As a result of the pressure elevation on that side of plate-like portion 28 which is impinged upon by pressure, there acts on plate-like portion 28 a pressure force, acting in lifting direction A, which overcomes the elastic force of diaphragm spring 38 as the pressure difference increases, so that plate-like portion 28, and with it counterpart surface 26, become displaced in lifting direction A away from end surface 24. An annular gap 42 (see FIG. 5), formed or existing between end surface 24 and counterpart surface 26, thereby becomes enlarged. The flow resistance in exhalation direction E between end surface 24 and counterpart surface 26 decreases as a result, so that an exhalation flow from proximal end 30 toward distal end 34 of exhalation valve 10 is possible with almost no impediment.

(22) The exhalation flow proceeding in exhalation flow direction E is constrainedly deflected at plate-like portion 28 of valve body 12 so that it flows in a radial direction, with reference to passage path portion D1, away from passage path portion D1 through annular gap 42.

(23) In order to stabilize this exhalation flow in that portion of flow passage 16 which is located directly downstream from annular gap 42 between end surface 24 and counterpart surface 26, valve body 12 comprises a skirt 44 that prevents the exhalation flow from flowing out exclusively radially after passing through annular gap 42, and deflects the exhalation flow again, this time in a flow direction having a directional component opposite to the exhalation flow direction directly upstream from valve body 12.

(24) Skirt 44 proceeds in a circumferential direction completely around body axis K of valve body 12 and surrounds both counterpart surface 26 and end surface 24. For that purpose, skirt 44 projects from plate-like portion 28 having counterpart surface 26, oppositely to lifting direction A, sufficiently far that it not only protrudes beyond end surface 24 oppositely to lifting direction A but completely radially externally surrounds an axial end portion, comprising end surface 24, of respiration tube 18. An annular gap space 46 (see FIG. 5), which allows exhalation flow to flow off even when counterpart surface 26 is only slightly lifted off from end surface 24, is constituted between respiration tube 18 and skirt 44.

(25) The result of the skirt which completely surrounds annular gap 42 at least when exhalation valve 10 is in the reference position is to achieve a stabilization of the exhalation flow in the region of the valve passthrough, which has considerably less tendency toward eddying and flow detachment compared with a similar valve body 12 having no skirt as has hitherto been used in the existing art, thereby enabling an exhalation flow accompanied by considerably less noise. Experiments have shown that an exhalation valve according to the present invention exhibits substantially reduced noise emission, compared with exhalation valves of the existing art, especially in a volumetric flow range of approximately 15 liters per minute.

(26) Skirt 44 can extend, oppositely to lifting direction A, sufficiently far from plate-like portion 28 and counterpart surface 26 embodied thereon, that an annular gap space 46 remains between skirt 44 and the outer side of respiration tube 18, until the lifting of counterpart surface 26 away from end surface 24 has exceeded a predetermined magnitude.

(27) As shown in FIG. 1, exposed rim 48 of skirt 44 can be a smooth rim that proceeds along a circular track around body axis K of valve body 12. Exposed rim 48 of skirt 44 can also, however, as shown in FIGS. 2, 3, and 6, have a wave shape, for example a triangular wave conformation having equilateral triangles of equal size succeeding one another in a circumferential direction. Alternatively, as depicted in FIG. 7, rim 48 of skirt 44 can be configured in partially-circular or sinusoidal form or, as shown in FIG. 8, can be configured as a rectangular wave shape. As shown in FIG. 5, respiration tube 18 can be equipped, radially outside end surface 24, with a bevel 50. Bevel 50 preferably proceeds completely around tube axis R of respiration tube 18 and constitutes, in interaction with plate-like portion 28 and skirt 44 projecting therefrom oppositely to lifting direction A, a radially externally acting expansion space 52 (see FIG. 5) into which the exhalation flow flowing radially through annular gap 42 between end surface 24 and counterpart surface 26 can expand.

(28) As shown in FIG. 5, protrusion length h over which skirt 44 projects, oppositely to lifting direction A, from plate-like portion 28 of valve body 12 is greater than radial spacing d between that end 54 of bevel 50 which is closer to end surface 24 and a radially inward-facing wall of skirt 44.

(29) As also shown in FIG. 5, skirt 44 extends oppositely to lifting direction A not only beyond end surface 24 but also beyond that end 56 of bevel 50 which is located farther from end surface 24.

(30) In the context of a wave-shaped embodiment of rim 48 of skirt 44, protrusion length h is to be determined out to an extreme point located farthest from counterpart surface 26, i.e. ignoring the wave troughs.

(31) As is evident from FIGS. 6, 7, and 8, the extreme points of the wave crests located farthest from counterpart surface 26 lie on a first plane E1 orthogonal to body axis K of valve body 12, and the extreme points of the wave troughs located closest to counterpart surface 26 lie on a second plane E2 parallel to the first. Planes E1 and E2 each proceed orthogonally to body axis K of valve body 12.

(32) On its side facing away from respiration tube 18, plate-like portion 28 of valve body 12 preferably comprises a reinforcing disk 60 that stabilizes the shape of plate-like portion 28. The remainder of valve body 12, with the exception of reinforcing disk 60, is preferably constituted integrally from a flexible elastomer, for example silicone, rubber, or natural rubber.

(33) Reinforcing disk 60 not only provides dimensional stabilization of plate-like portion 28 but also forms, with its stable and hard externally exposed surface 62 (see FIG. 2), an engagement surface for an actuator 63 for forced displacement of plate-like portion 28 (and, with it, counterpart surface 26) toward end surface 24. In the interest of clarity, only half an actuator plunger 64 is depicted with dashed lines and indicated in FIG. 1.

(34) Actuator 64 can be brought into abutting engagement with reinforcing disk 60 by being lowered toward it. Once the abutting engagement is established, the entire plate-like portion 28, together with the reinforcing disk, can be moved toward end portion 22 of respiration tube 18 by lowering actuator plunger 64 farther. Plunger 64 can be lifted away from reinforcing disk 60 by being pulled back in lifting direction A. Plunger 64 can be electromagnetically driven to move. It can likewise be driven by an electric-motor drive system, by means of a linkage, to move along body axis K.

(35) FIG. 4 is an enlarged depiction of a detail of valve body 12 of FIG. 3.

(36) In the section plane that encloses body axis K of valve body 12, skirt 44 preferably encloses with the plane of the preferably flat counterpart surface 26 an angle α that is 90 degrees or slightly more than 90 degrees. Angle α is preferably in a range from 90 to 95 degrees, particularly preferably up to 92.5 degrees.

(37) Radial thickness s of skirt 44 is preferably substantially constant along its protrusion length h, with the exception of an unavoidable transition curvature at the transition to plate-like portion 28. It is preferably no more than 10% greater or less than the radial extent of annular gap space 46 between the radially outward-facing surface of respiration tube 18 and the radially inward-facing wall surface of skirt 44.

(38) With the exhalation valve described here it is possible to considerably decrease the noise produced in the context of flow during an exhalation event, with no increase in flow resistance. It is likewise possible, with the exhalation valve that has been presented above, to reliably prevent flow through valve housing 14 in a flow direction opposite to exhalation flow direction E.

(39) FGG. 9 shows a ventilation apparatus 70 including a respiratory gas pump 72, conveying respiratory gas through an inspiratory gas via an inspiratory valve 74 to a patient P. From the patient P expiratory gas is exhaled through expiratory gas expiratory valve 10, as shown in detail in the already existing drawings and described above.