Exhalation valve

Abstract

PROBLEM TO BE SOLVED: To provide an expiratory valve to avoid or at least reduce problems in prior arts.SOLUTION: The present invention relates to an expiratory valve (10) of a ventilation device (100), comprising a valve body (12) having a fluid inlet (14) and a fluid outlet (16) for breathing air of a patient formed therein, the valve body (12) defining a fluid flow path between the fluid inlet (14) and the fluid outlet (16), with the cross-sectional area of the fluid flow path expanding toward the fluid outlet (16).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an exhalation valve for a ventilator, the exhalation valve being formed with a fluid inlet and a fluid outlet for a patient's breathing air and comprising a valve body defining a fluid flow path between the fluid inlet and the fluid outlet, the cross-sectional area of ​​the fluid flow path expanding in a direction towards the fluid outlet.

[0002] This exhalation valve is used in a ventilator for the mechanical ventilation of a patient. The invention also relates to such a ventilator. [Background technology]

[0003] In mechanical ventilation, breathing air is supplied to the patient in a mechanical manner, usually under positive pressure. Mechanical ventilation can support the patient's own breathing or can completely replace the patient's own breathing. The supply of breathing air is performed in successive ventilation cycles. Each ventilation cycle includes an inhalation phase followed by an exhalation phase. During the inhalation phase of each ventilation cycle, ventilation air is supplied at positive pressure against the pressure prevailing in the patient's airways, usually mechanically or in any case in a machine-assisted manner. Exhalation occurs during the subsequent expiratory phase of the ventilation cycle. Typically, no positive or negative pressure is applied to the airways during the expiratory phase. Rather, exhalation occurs passively by relaxing the airways against the ambient pressure, and the patient's own expiratory effort is assisted as much as possible. Exhalation of breathing air and expulsion of breathing air to the environment are effected with the aid of an exhalation valve as described herein. The exhalation valve is arranged in the ventilation system in a conduit for exhaled air, usually downstream of this conduit. On the side facing away from the patient, ambient pressure usually prevails. When a positive pressure against this pressure is applied to the valve from the patient's side during the exhalation phase, the exhalation valve will open and allow the exhaled air to escape to the environment. When doing so, the exhalation valve will reliably recognize the beginning and end of the exhalation phase and react accordingly. For this purpose, a valve membrane is used that opens or closes the passage of fluid between the airway and the environment, depending on whether a sufficiently high positive pressure exists on the side facing the airway relative to the side facing the environment.

[0004] In the past, problems often occurred that the exhalation valve generated unpleasant loud noises during operation. In some cases, it was even observed that oscillating pressure fluctuations in the exhaled air were generated or increased by the exhalation valve, which ultimately led to malfunctions in ventilation. In the case of this phenomenon, known as auto-triggering or auto-cycling, the pressure fluctuations generated or increased by the exhalation valve are erroneously detected by the ventilator as the end of the expiratory phase, which leads to the ventilator prematurely starting the next inhalation phase. This is very unpleasant for the mechanically ventilated patient and may even pose a danger to the mechanically ventilated patient. The exhalation valve according to the invention is intended to avoid or at least reduce such problems. Summary of the Invention [Means for solving the problem]

[0005] In comparison with the exhalation valves used up to now, the exhalation valve according to the invention allows for an improved guidance of the exhaled air, as described in the first paragraph of this disclosure. In particular, the exhalation valve is more sensitive in its reaction to the beginning and end of the exhalation phase, and the generation of noise during the movement of the exhalation valve is significantly suppressed. Furthermore, it is possible to better control the phenomenon of automatic triggering or automatic cycling.

[0006] The cross-sectional area of ​​the fluid flow passage, which expands in the direction toward the fluid outlet, is particularly well matched to the increasing volumetric flow rate of the fluid (exhaled air) flowing during exhalation through an exhalation valve opened in this manner, toward the fluid outlet. The larger the volumetric flow rate, the larger the cross-sectional area available in the fluid flow passage. In particular, the partial volumes of the fluid flow passage for each equally sized angular portion vary along the circumference of the fluid inlet, such that these partial volumes increase in the direction toward the fluid outlet. This reduces the formation of turbulence and disturbances in the fluid flow, providing the possibility for the exhalation valve to react in a much more reliable, but at the same time more sensitive manner, to changes in the flow of exhaled air in the airway. The adverse pressure effects, which often lead to the failure of the aforementioned automatic trigger with conventional exhalation valves, are much less likely to occur.

[0007] The cross-sectional area of ​​the fluid flow path is understood to be the area of ​​space available for fluid flow in a cross-sectional area transverse to the main direction of fluid flow between the fluid inlet and the fluid outlet when the exhalation valve is opened, specifically in a cross-sectional area perpendicular to that main direction.

[0008] The exhalation valve is designed so that during exhalation, i.e. during the exhalation phase, breathing air can enter the exhalation valve by means of the fluid inlet, which is now open, and in particular into the valve plenum enclosed by the exhalation valve. During the inhalation phase, the fluid inlet is preferably closed.

[0009] The fluid outlet is designed to allow exhaled breathing air to be discharged to the environment.

[0010] In an embodiment, the valve body defines a cup-shaped valve plenum, which is at least partially surrounded on the lower side by a valve base, in particular by a valve base formed by the valve body, and optionally starting from the valve base and by an outer edge also constituted by the valve body, into which the fluid inlet opens. On the upper side of the cup-shaped valve plenum, the valve plenum can be enclosed by a valve membrane constituting a cover. The valve plenum defines a cavity, which cavity can contain a fluid (exhaled breathing air) that is added via the fluid inlet and from which the fluid (exhaled breathing air) can be discharged via a fluid outlet. In particular, the valve plenum has a fluid flow path formed between the fluid inlet and the fluid outlet. In particular, the valve plenum is at least partially enclosed on its lower side by the valve base, and the fluid inlet opens into the valve base. The valve base can in particular extend in a dish-like manner between the fluid inlet and the outer edge of the valve body (in particular the valve plenum), while the outer edge of the valve base constitutes the outer edge of the valve body. The term "dish-shaped" indicates that the valve base extends in a substantially flat or flattened conical manner between the fluid inlet and the outer edge, apart from a possible passageway recess around the fluid inlet, which will be described in more detail further. The fluid inlet is in particular formed in the center of the valve base. The fluid inlet may in particular have a circular cross-sectional area with a fluid entry face that is also circular.

[0011] The valve base may start, in particular, from the edge of the fluid inlet that defines the fluid entry surface. No step is created between the fluid entry surface and the valve base. In this manner, a sharp edge boundary of the fluid inlet to the valve plenum is avoided. This promotes the formation of a fluid flow as gently as possible to the exhalation valve as well as through the exhalation valve during the exhalation phase. In the case of known exhalation valves, the fluid inlet, in contrast, protrudes into the valve plenum, in particular the fluid inlet protrudes a certain distance beyond the valve base. Therefore, the valve base does not start from the edge of the fluid inlet that defines the fluid entry surface, and the fluid flow passes through a step when flowing into the valve plenum, which increases the formation of turbulence and stalls or separation of airflow in the fluid flow flowing into the exhalation valve.

[0012] A reduction in noise generation and in the effects of retrograde pressure is also advantageously possible when the valve plenum has an aerodynamically efficient design for the flow along the fluid flow path between the fluid inlet and the fluid outlet. The aerodynamically efficient design of the valve plenum, in particular of the fluid flow path, can be particularly enhanced when the valve base, starting from the inside of the fluid inlet at the edge of the fluid entry face, has a rounded contour on the side facing the valve plenum. Thus, the fluid flow entering the valve plenum from the fluid inlet reaches the fluid flow path in a substantially non-swirling manner and without stall and flows towards the fluid outlet. This results in a reduction in operating noise when the fluid outlet is opened. Furthermore, the effects of retrograde pressure on the breathing air conduit connected to the fluid inlet are effectively suppressed, so that the risk of false detection of the end of the expiratory phase by the ventilator is reduced.

[0013] In particular, a flow-optimized design of the valve plenum, in which only rounded contours are formed along the fluid flow path in the valve plenum from the fluid inlet to the fluid outlet, is considered to constitute a subject of the present invention that is independent of being worthy of protection, and the applicant reserves the right to claim independent protection for this, independent of the configuration of the fluid flow path with an expanding cross-sectional area towards the fluid outlet.

[0014] Certain embodiments may be formed such that the valve base bulges axially in the area around the fluid inlet. The term "bulging axially" indicates that the valve base has a convex configuration at least in a cross section including the fluid inlet axis, i.e. in the area located between the edge of the fluid inlet and the outer edge of the valve base. Convex means that in such a cross section, a line connecting two points on the valve base extends through the valve plenum. The valve base thus forms a groove or passage extending around the fluid inlet, the bottom of said passage bulging axially between the edge of the fluid inlet and the outer edge of the valve base. In such designs, the cross-sectional area of ​​the fluid flow path between the fluid inlet and the fluid outlet presents itself in each case as the area of ​​the valve plenum in a radial cross section from the fluid inlet axis to the outer edge of the valve plenum. In contrast, the valve base of exhalation valves currently in use has a flat conical configuration, i.e. does not form a bulge or protrusion.

[0015] Specifically, the design may be such that the axial bulge or protrusion has a depth that varies around the circumference of the fluid inlet. The depth of the bulge may be defined as the distance, measured axially between the valve base at the edge of the fluid inlet and the valve base at the deepest point of the bulge along a cross section from the edge of the fluid inlet to the outer edge of the valve base. Specifically, the depth of the bulge will increase in the circumferential direction toward the fluid outlet. Thus, the partial volumes of the bulge for each equal sized angular portion vary along the circumference of the fluid inlet such that these partial volumes increase in magnitude in the direction toward the fluid outlet. In certain embodiments, the depth of the bulge in the circumferential direction may be smallest on the side opposite the fluid outlet and largest in the circumferential direction on the side located toward the fluid outlet.

[0016] As mentioned above, the fluid inlet may be located in a central portion of the valve plenum, and the fluid outlet may be located at a further outer location relative to the fluid inlet, in particular radially outward, in particular at the outer edge of the valve plenum. In the case of a central location of the fluid inlet, the cross-sectional area of ​​the fluid flow path between the fluid inlet and the fluid outlet shows itself in each case as the cross-sectional area of ​​the valve plenum in a respective radial section from the fluid inlet axis to the outer edge of the valve plenum.

[0017] The valve body can in particular be made of a plastic material. For example, it is convenient to manufacture the valve body in an injection molding process. The valve body is therefore an injection molded part. For example, the valve body together with the valve base can be made of a plastic material suitable for injection molding, such as polyethylene, polypropylene or another thermoplastic material.

[0018] In a particular embodiment, the valve body may have a fluid inlet section in which the fluid inlet is formed. In particular, the fluid inlet section may be formed integrally with the valve body and thus, if the valve body is an injection molded part, may be formed as an injection molded part. In particular, the fluid inlet section may extend from the valve base, in particular from the lower side of the valve base. The fluid inlet section may extend, for example, perpendicular to the valve base. The fluid inlet axis specifies an imaginary line in the longitudinal direction of the fluid inlet section, which imaginary line is centered relative to the fluid inlet section. In the case where the fluid entry surface is perpendicular to the fluid inlet, the fluid inlet axis is perpendicular to the fluid entry surface defined by the fluid inlet and centered relative to the fluid entry surface. In a particular embodiment, the fluid inlet section may define a first pin-like projection that may be designed for the connection of a breathing air tube. For example, the first pin-like projection may have a cylindrical or conical shape, in particular may be designed as a cylindrical or conical tube fitting in which the fluid inlet is formed. The fluid inlet may specifically have a circular cross-sectional area.

[0019] In a particular embodiment, the valve body may have at least one strengthening or reinforcing rib formed around the fluid inlet. The valve body may specifically be provided with a plurality of reinforcing ribs formed around the fluid inlet. The plurality of reinforcing ribs may be provided in succession around the periphery of the fluid inlet, specifically at a specific distance from each other. For example, only one reinforcing rib may be designed as a solid body that at least partially surrounds the fluid inlet. The reinforcing rib is specifically formed on the lower side of the valve base, thus on the side of the valve base facing away from the fluid flow path, so as not to interfere with the fluid flow between the fluid inlet and the fluid outlet.

[0020] The one or more reinforcing ribs are adapted to strengthen or stiffen the valve base, in particular in the bulging portion surrounding the fluid inlet. The provision of the reinforcing ribs results in an increase in the second moment of the area of ​​the valve disc, in particular the valve base, over the cross-sectional area of ​​the fluid flow passage. The valve disc becomes more torsionally resistant in this area, so that the fluid flow entering the valve plenum and flowing along the fluid flow passage causes less vibration of the valve disc, in particular the valve base. This, among other things, reduces the generation of noise, but also results in much smaller adverse pressure effects that would be felt in the breathing air conduit connected to the fluid inlet.

[0021] It is advantageous for the at least one reinforcing rib to be formed integrally with the valve body, the term integral being understood to mean that the at least one reinforcing rib and the valve body are manufactured as one component, e.g. the at least one reinforcing rib is produced in the same injection molding process as the valve body, in particular as a single-component injection molded part.

[0022] The at least one reinforcing rib may advantageously extend outwardly relative to the edge of the fluid inlet. The term outwardly indicates the direction of the at least one reinforcing rib, which is arranged to strengthen or reinforce as efficiently as possible the part of the valve base between the edge of the fluid inlet and the outer edge of the valve base. In particular, the at least one reinforcing rib may extend radially relative to the center of the cross-sectional area of ​​the fluid inlet. However, it is also conceivable that the at least one reinforcing rib does not extend exactly radially, but additionally extends in the circumferential direction, for example spirally towards the outer edge of the valve base. The at least one reinforcing rib may in particular be arranged on the outer side of the edge of the fluid inlet.

[0023] The at least one reinforcing rib may include at least one first reinforcing rib and at least one second reinforcing rib. The at least one first reinforcing rib is an inner reinforcing rib arranged radially inside the second reinforcing rib. Thus, the at least one second reinforcing rib is an outer reinforcing rib. The at least one first reinforcing rib specifically extends outwardly from the edge of the fluid inlet along the valve base. The at least one second reinforcing rib specifically extends inwardly from the outer edge of the valve base. The at least one first reinforcing rib specifically extends between the edge of the fluid inlet and the bulging portion of the valve base. The at least one second reinforcing rib specifically extends between the bulging portion of the valve base and the outer edge of the valve base. Specifically, the at least one second reinforcing rib is interrupted at a brim-shaped shoulder formed on the outer edge of the valve base. The shoulder can, for example, have at least one step, preferably at least two spaced apart steps, extending around the edge of the valve base, with at least one second reinforcing rib merging into the step or into an inner one of the steps, respectively.

[0024] Furthermore, the valve body may specifically define a fluid outlet section in which the fluid outlet is formed. The fluid outlet section may specifically have a second pin-like projection. The fluid outlet section may specifically be formed integrally with the valve body, for example also in the form of an injection molded part. The second pin-like projection may specifically have a cylindrical or conical shape. If desired, the second pin-like projection may be formed, for example, as a cylindrical or conical tube fitting in which the fluid outlet is formed. However, the second projection will often open directly to the environment. The fluid outlet section may specifically have a circular cross-sectional area.

[0025] A bulging portion of the valve base that defines a fluid flow path between the fluid inlet and the fluid outlet may merge with the fluid outlet. Specifically, the bulging portion of the valve base may merge with a sidewall of the fluid outlet. Specifically, a groove or passage defined by the bulging valve base has a maximum depth at the transition to the fluid outlet.

[0026] As with the fluid inlet, the fluid outlet may also extend, in particular from the valve base, in particular from the lower side of the valve base. The fluid inlet may extend perpendicular to the valve base.

[0027] Furthermore, it is advantageous when the valve body has a support on which the valve leaflet can rest with an abutment area formed at its outer edge, the support having a non-uniform design on its upper side.

[0028] As described above, the exhalation valve further comprises a valve membrane associated with the fluid inlet, which can be displaced at least between a position that closes the fluid inlet and a position that opens the fluid inlet. The valve membrane may be designed without its own actuation, so that it can be displaced between the closed and open positions only by a pressure difference between its side facing the fluid inlet and its side facing away from the fluid inlet. However, additionally or alternatively, an actuator may be provided that displaces the valve membrane back and forth between the closed and open positions. This actuator is preferably actuated by the ventilation device. This valve membrane has its own abutment area, which is formed on the outer edge of the valve membrane and presses against the upper side of the support. The exhalation valve in particular further comprises a fastening member, for example a fastening ring, which cooperates with the valve body in such a way that the fastening member establishes a fastening engagement with the valve membrane. In particular, the valve membrane is fixed to the valve body by means of this fastening engagement, which is brought about at the outer periphery of the valve membrane by the fastening member. In this regard, the valve leaflets may be secured to the valve body by the fastening member in such a manner that the leaflets may be brought into a position that opens the fluid inlet to the valve plenum when a positive pressure exists on the side associated with the fluid inlet compared to the side associated with the valve plenum, unless this is the case, specifically when there is equal or negative pressure on the side associated with the fluid inlet compared to the side associated with the valve plenum, the leaflets remain in a position that closes the fluid inlet to the valve plenum.

[0029] The invention also relates to a ventilation device comprising an exhalation valve of the type described above which can be connected to an exhalation air conduit.

[0030] The invention will be explained in more detail below by means of embodiments with reference to the drawings. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 shows a ventilator for mechanical ventilation of a patient, comprising a control device, a monitoring device, a tube for supplied breathing air, and a tube for exhaled air. [Diagram 2]FIG. 1 is a cross-sectional view of an exhalation valve according to an embodiment. [Diagram 3] 3 is a perspective view of the valve body of the exhalation valve of FIG. 2 from below. [Figure 4] 3 is a top perspective view of the valve body of the exhalation valve of FIG. 2.

[0023] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] For similar or functionally similar components, the same reference numbers are used in all figures. A detailed description of such components is in each case provided for the first figure showing the respective reference number. Unless expressly indicated otherwise, it is understood that the same description also applies to all other figures in which components with the same reference numbers are shown.

[0033] FIG. 1 shows a ventilator 100 for mechanical ventilation of a patient. The ventilator 100 comprises a control device 110, a monitoring device 120, a rack 102 movable on rollers with a conduit 130 for ventilation air supplied by the device and a conduit 140 for expired air. The conduit 130 for the ventilation air supplied comprises a first ventilation air pipe 132 extending from the control device 110 to a humidifier 134, where the ventilation air is passed through a water container. From the humidifier 134 a second ventilation air pipe 136 extends to a T-piece 138. From the T-piece the ventilation air provided by the ventilator 100 during the inspiration phase of the ventilation cycle is delivered to the patient via a conduit 150. Via the conduit 150 the air expired by the patient during the expiration phase of the ventilation cycle is also returned to the ventilator 100. For this purpose, an additional breathing air tube 142 belonging to a conduit 140 for exhaled air branches off from the T-piece 138. The breathing air tube 142 leads to an exhalation valve, generally designated 10, which will be explained in more detail below with reference to Figures 2 to 4.

[0034] FIG. 2 shows a cross-sectional view of an exhalation valve 10 according to an embodiment as used in FIG. 1. The exhalation valve 10 comprises a valve body 12 in which a fluid inlet 14 and a fluid outlet 16 for breathing air exhaled by the patient are formed. FIGS. 3 and 4 show perspective views of this valve body 12, with FIG. 3 showing a view from below, approximately in the direction of the arrow marked with the number 12 in FIG. 4, and FIG. 4 showing a view from above, approximately in the direction of the arrow marked with the number 12 in FIG. 3. FIG. 2 shows the exhalation valve 10 before installation in the ventilator 100, so that the breathing air tube 142 is not yet connected. In the operating state, i.e. after installation of the exhalation valve 10 in the ventilator 100 according to FIG. 1, the breathing air tube 142 is connected to the fluid inlet 14. Thus, the air exhaled by the patient is passed to the exhalation valve 10 via the fluid inlet 14. After passing through the exhalation valve 10, the exhaled air is directed through the fluid outlet 16 into the surrounding environment of the ventilator 100.

[0035] The exhalation valve 10 comprises a so-called valve plenum 18. The valve plenum 18 defines a cavity adapted to be acted upon by a fluid (exhaled breathing air) applied via a fluid inlet 14, from which the fluid (exhaled breathing air) can be discharged via a fluid outlet. In the valve plenum 18, a fluid flow path is thus formed between the fluid inlet 14 and the fluid outlet 16 by the valve body 12 and the valve membrane 20. The fluid inlet 14 allows breathing air to enter the valve plenum 18 during exhalation, i.e. during the expiratory phase of the ventilation cycle. During the inhalation phase of the ventilation cycle, i.e. when breathing air is mechanically supplied to the patient via the ventilation conduit 130, the fluid inlet 14 will be closed. For this purpose, a valve membrane 20 associated with the fluid inlet 14 is provided. The valve membrane 20 can be displaced at least between a position that closes the fluid inlet 14 and a position that opens the fluid inlet 14. The leaflets 20 are specifically designed such that the center of the leaflets 20 abuts against the fluid inlet 14 to close the fluid inlet opening 22 formed in the fluid inlet 14, as long as the pressure on the side of the leaflets 20 associated with the fluid inlet 14 is within a certain pressure of the pressure prevailing on the side of the leaflets 20 facing away from the fluid inlet 14 (usually the ambient pressure). The leaflets 20 are then in a position to close the fluid inlet 14 or conduit 140 to the valve plenum 18. This is the position taken by the leaflets 20 during the inspiration phase. If there is a sufficiently high positive pressure on the side associated with the fluid inlet 14 or conduit 140 for exhaled air compared to the pressure on the side facing away from the fluid inlet 14 or conduit 140 for exhaled air, the leaflets 20 move to a position to open the fluid inlet 14 to the valve plenum 18, so that breathing air from the conduit 140 for exhaled air can flow into the valve plenum 18. This usually occurs during the exhalation phase. The valve leaflet 20 is made of a plastic material, in particular a resilient plastic material, for example a silicone or polysiloxane plastic material. The valve leaflet 20 can be placed in a biased manner to abut against the edge 26 of the fluid inlet 14 surrounding the fluid inlet opening 22, without any positive pressure being applied on the side facing the conduit 140 for the exhaled air.When a sufficiently large positive pressure is applied to the side facing the conduit 140 for exhaled air, the leaflets 20 disengage from the edge 26 of the fluid inlet 14 surrounding the fluid inlet opening 22, so that the exhaled breathing air can flow into the valve plenum 18. However, additionally or alternatively, an actuator may be provided which displaces the leaflets 20 in a reciprocating manner between the closed and open positions. This actuator is preferably driven by the ventilation device and engages, for example, in a central portion of the leaflets 20 on the side of the leaflets 20 facing away from the fluid inlet opening 22. The respective positions of the leaflets 20 determine the volume of the leaflets 20 and the valve plenum 18 formed between the leaflets 20 and the valve disc 12.

[0036] The valve body 12 comprises a valve base 24 extending outward from the fluid inlet 14 on the lower side of the valve plenum 18, reaching the outer edge or the valve base of the valve plenum. The valve base 24, together with the valve membrane 20, defines a fluid flow path formed in the valve plenum 18 between the fluid inlet 14 and the fluid outlet 16. In particular, the valve body 12 in certain embodiments is at least partially enclosed on the lower side by the valve base 24, forming a cup-shaped valve plenum 18 into which the fluid inlet 14 opens. The valve base 24 can in particular extend in a dish-like manner between the fluid inlet 14 and the outer edge of the valve body 12 (in particular the valve plenum 18), while the outer edge of the valve base 24 constitutes the outer edge of the valve body 12. The fluid inlet 14 is in particular formed in the center of the valve base 24. The fluid inlet 14 can in particular have a circular cross-sectional area and a fluid entry face 22 that is also circular. Thus, the edge 26 of the fluid inlet 14, which defines the fluid entry surface 22, forms the inner edge of the valve base 24, which begins at the edge 26 on the lower side of the valve plenum 18 and extends to the outer edge of the valve disc 12. The outer edge of the valve disc 12 in the radial direction is located furthest away from the fluid inlet 14. Thus, the edge 26 at least does not protrude from the valve base 24 abruptly or with a sharp edge, but rather the valve base 24 begins directly at the edge 26 of the fluid inlet opening 22 and extends outwardly from this edge 26 in a smoothly curved contour. This configuration avoids sharp edges that can cause airflow separation and associated noise generation as air flows around it.

[0037] The valve base 24 has a dished configuration, which means that the valve base 24 extends substantially flat or in a mostly flattened cone shape between the inner edge 26 and the outer edge of the valve base 24. Possible recesses in the valve base 24, such as grooves or passages, which will be described in more detail further below, are shaped to have various smooth converging curvatures to create an overall rounded flow matching profile.

[0038] While the fluid inlet 14 is located in the center of the valve plenum 18, the fluid outlet 16 is located radially further outward relative to the fluid inlet 14. In particular, the fluid outlet 16 is located at the outer edge of the valve plenum 18. At the location of the valve outlet 16, the valve body 12 is provided with an outlet opening, in particular in the outer wall of the valve base 24, through which breathing air can flow from the valve plenum 18 to the fluid outlet 16. The outlet opening is also provided with smoothly curved edges and therefore has a favorable configuration for flow, so that a flow of breathing air along sharp edges at the discharge from the valve plenum 18 is avoided.

[0039] The valve body 12 is made of a plastic material, for example polyethylene, polypropylene, or another thermoplastic material. The valve body 12 is an injection molded part, i.e., is manufactured by an injection molding process. In particular, the valve body 12 may be designed so that it can be manufactured in a single injection molding process, in particular in the form of a single-component injection molded part.

[0040] The valve body 12 has a fluid inlet section 28 in which the fluid inlet 14 is formed. The fluid inlet section 28 is specifically formed integrally with the valve body 12. The fluid inlet section 28 extends away from the valve bottom 24 in a direction from the lower side of the valve bottom 24 substantially along the axial direction A of the fluid inlet 14. The fluid inlet section 28 also extends transversely to the valve bottom 24, i.e. protrudes from the lower side of the valve bottom 24 in the axial direction A of the fluid inlet 14. The axial direction A specifies a fluid inlet axis, i.e. specifies an imaginary line in the longitudinal direction of the fluid inlet section 28 that is centered with respect to the fluid inlet 14. Since the fluid entry face 22 is disposed at right angles to the fluid inlet 14, the fluid inlet axis A extends at right angles to the fluid entry face 22 defined by the fluid inlet 14 and is centered with respect to the fluid entry face 22.

[0041] The fluid inlet part 28 in particular forms a first pin-like projection which is adapted for connecting a breathing air tube, for example the breathing air tube 142 shown in Fig. 1. In the variant shown in Fig. 2, the first pin-like projection in particular has a cylindrical shape. In another refinement, the pin-like projection may be formed slightly tapered towards its free end, for example slightly conically tapered. The first pin-like projection may in particular be formed as a tube fitting in which the fluid inlet 14 is formed.

[0042] The valve body 12 further defines a fluid outlet section 30 in which the fluid outlet 16 is formed. The fluid outlet section 30 may specifically form a second pin-like projection, which may have a cylindrical or tapered shape, specifically a conical shape. The second pin-like projection may be formed, for example, as a cylindrical tube fitting in which the fluid outlet 16 is formed. The fluid outlet section 30 may also specifically be formed integrally with the valve body 12. The fluid outlet 16 may specifically have a circular cross-sectional area. The fluid outlet 16 does not necessarily have to be connected to a further conduit, but may open directly to the surroundings, so that the exhaled air is discharged through the fluid outlet 16 to the surrounding environment. The fluid outlet section 30 is connected at its radially inner side to the valve plenum 18 through the aforementioned outlet opening, so that the fluid flowing to the exhalation valve 10 is passed to the fluid outlet section 30 through the outlet opening.

[0043] Similar to the fluid inlet portion 28, the fluid outlet portion 30 may extend specifically from the valve base 24, and more particularly from the lower side of the valve base 24. The fluid outlet portion 30 may extend perpendicular to the valve base 24 and / or in a direction parallel to the fluid inlet portion 28, as can be readily seen in Figures 2-4.

[0044] The fluid flow path in the valve plenum 18 has a cross-sectional area that increases from the fluid inlet 14 toward the fluid outlet 16, as measured transversely to the fluid flow between the fluid inlet 14 and the fluid outlet 16. This is achieved by the particular configuration and arrangement of the valve body 12, specifically the valve base 24 and the valve membranes 20. The valve base 24 primarily bounds the fluid flow path on the bottom side. The valve membranes 20 primarily bound the fluid flow path on the top side. It is quite convenient to utilize a valve membrane 20 similar to a conventional valve membrane, but the valve base 24 is designed such that the cross-sectional area of ​​the fluid flow path increases toward the valve outlet 16. Specifically, the valve base 24 is designed such that its distance from the valve membranes 20 increases from the fluid inlet 14 toward the fluid outlet 16. This can be done in one or more stages, but specifically, it is done continuously from the fluid inlet 14 toward the fluid outlet 16. Due to the shape of the exhalation valve 10 shown in Figures 2-4, in which the fluid inlet 14 is located radially inward and centrally, and the fluid outlet 16 is located radially outward, it is advantageous to design the fluid flow path in such a way that, for example, the partial constant volume of the fluid flow path for each equally sized angular portion around the fluid inlet 14 varies along the circumference of the fluid inlet 14, increasing in size in the direction toward the fluid outlet 16. Such an effect can be achieved, for example, when the plane along which the valve base 24 extends is inclined relative to the plane along which the valve membrane 20 extends, so that these two planes extend away from each other toward the fluid inlet 14. For example, although the valve membrane 20 typically extends in a plane perpendicular to the fluid inlet axis A (in Figures 2 and 3, this plane is very diagrammatically indicated by the dashed line marked with the symbol C), there may be certain embodiments in which the valve base 24 can extend along a plane inclined at a different angle of 90 degrees to the fluid inlet axis A. The plane along which the valve base 24 extends is intended to designate a plane that follows the extension of the center of the valve base 24, while disregarding possible individual (e.g., dimple-like) bumps and recesses in the valve base 24.However, the valve base 24 has a continuous recess that determines the cross-sectional area of ​​the flow path between the fluid inlet 14 and the fluid outlet 16, as described further below, so that the plane along which the valve base 24 extends will generally be determined by the path of this recess (i.e. the path of the deepest points in the continuous cross-sections following the fluid flow path). In Figures 2 and 3, the location of this plane is shown very diagrammatically by line B. It can be seen that this plane is not parallel to the plane along which the valve membrane 20 extends (which plane extends perpendicular to the fluid inlet axis A), but rather forms an angle with the fluid inlet axis A that differs by 90 degrees. This means that the normal vector N of this plane is not parallel to the fluid inlet axis A, but rather forms an angle α with the fluid inlet axis A. Typically, the normal vector N will be inclined towards the fluid outlet 16 with respect to the fluid inlet axis A, as also shown in Figures 2 and 3.

[0045] The increase in cross-sectional area of ​​the fluid flow path toward the fluid outlet 16 accounts for the fact that the volumetric flow rate of breathing air flowing toward the outlet increases as the distance of the fluid flow path from the fluid outlet decreases. Thus, the volume available for volumetric flow in the valve plenum 18 is matched with the volumetric flow rate. Because of this match of the volume available for fluid flow, stall effects on the resulting swirl of exhaled breathing air are avoided.

[0046] It can be easily seen from Figs. 2 to 4 that the valve base 24 further bulges axially outward in the area around the fluid inlet 14. The expression "bulges axially" is to be understood to mean that the valve base 24 has a convex shape at least in a cross section including the fluid inlet axis A, i.e. in the area between the edge of the fluid inlet 14 and the outer edge of the valve base 24. In the illustrated embodiment, this can also be a radial cross section. In Fig. 2, this convex shape is shown for a cross section through the deepest place of the thus formed bulge 32 at the fluid outlet 16 on the left side of Fig. 2, and for a cross section through the first depth of the bulge 32 on the right side of Fig. 2. Convexity means that in such a cross section, a line connecting two points on the valve base 24 to each other extends through the valve plenum 18. The valve bottom 24 thus forms, in the region of the bulge 32 thus created, a groove or passageway having a floor extending around the fluid inlet 14 and bulging in the axial direction between the edge of the fluid inlet 14 and the outer edge of the valve bottom 24. The passageway thus defines a fluid flow path around the fluid inlet 14. The respective deepest points of this passageway along the fluid flow path (in other words, the succession of the deepest points in the respective cross sections between the fluid inlet 14 and the outer edge of the valve bottom 24) thus form a line extending around the fluid inlet 14 and marked with the reference number 34 in FIG. 3. As shown in the figure, due to the radially symmetrical shape of the valve bottom 24 with the fluid inlet 14 at its center, this line 34 has an elliptical shape due to the different depths of the passageway which will be outlined in more detail further on (the projection of this line 34 in a plane such as the plane C perpendicular to the fluid inlet axis A has a circular shape). As can be readily seen in Figures 2-4, the bulged portion of the valve bottom 24 (or the passages thus formed) defines two fluid flow paths that extend substantially around half the circumference of the fluid inlet 14, which ultimately open at a lateral side (to the left of the fluid inlet 14 in Figure 2) into the fluid outlet 16. At this point, the bulged portion of the valve bottom 24 has an outer sidewall that merges into the fluid outlet 30. As previously mentioned, all edges along the fluid flow paths are provided with rounded contours to reduce stall in the fluid flow or separation and / or swirling of the airflow.

[0047] The figures clearly show that the axial bulge 32 of the valve base 24 is of different depths around the circumference of the fluid inlet 14. The depth is measured as the distance measured in the direction of the fluid inlet axis A between the valve base 24 at the edge 26 of the fluid inlet 14 and the valve base 24 at the deepest point of the bulge 32 in a cross section interconnecting the fluid inlet 14 to the outer edge of the valve base 24 (in the case of a radially symmetrical shape of the valve base 24 as shown in the figures, this is a radial cross section through the valve base 24). Figures 2 and 3 each show the maximum depth Tmax at the location of the fluid outlet 16 and the respective minimum depth Tmin on the opposite side of the fluid outlet 16.

[0048] Thus, the partial volumes of the fluid flow paths for the respective angular portions of equal magnitude in each case vary along the circumference of the fluid inlet 14 such that these partial volumes increase with decreasing distance from the fluid outlet 16. This measure contributes significantly to reducing the noise caused by the flow when expelling breathing air during the expiratory phase, since the available volume is matched to the volumetric flow rate of the flowing fluid.

[0049] The figure also clearly shows that the valve bottom 24 has a rounded contour at the edge of the fluid entry face 22 on the side facing the valve plenum 18, starting from the inside of the fluid inlet 14. This is particularly clearly revealed in FIG. 4. In passing the fluid entry face 22, the fluid flow passes along the rounded inner edge of the passage formed by the bulge 32 to the deepest part of the bulge 32, in order to flow along the fluid flow path formed by the passage following the approximate line 34 around the fluid inlet 14 towards the fluid outlet 16. In doing so, the fluid flow does not pass any sharp edges that could cause stall or swirling with the accompanying noise generated.

[0050] The valve body 12 further shows reinforcing ribs 36, 38 formed around the fluid inlet 14. In Fig. 2 and Fig. 3, some of these reinforcing ribs are shown in an exemplary manner under the references 36 and 38. The reinforcing ribs 36, 38 reinforce the valve base 24, in particular the shell formed by the valve base 24 in the bulging portion 32. Torsion of the valve body 12 is effectively suppressed by the additional reinforcement. The reinforcing ribs 36, 38 therefore also contribute to reducing the generation of noise, since they suppress the vibrations of the valve body 12 under the influence of the fluid flow in the valve plenum 18. However, it is also possible to effectively suppress undesirable disturbing vibrations of the valve membrane 20. This reduces the risk of vibrations of the air column in the tubing system, which may result in erroneously operated control actions, in particular so-called automatic triggers. The reinforcing ribs 36, 38 are formed integrally with the valve body 12. In this respect, integral is to be understood to mean that the reinforcing ribs 36, 38 and the valve body 12 are manufactured as a single component. In the illustrated embodiment, the reinforcing ribs 36, 38 are manufactured in the same injection molding process as the valve body 12.

[0051] The reinforcing ribs 36, 38 are arranged on the outside of the fluid inlet 14. As can be seen in the figure, the reinforcing ribs 36, 38 extend outwardly relative to the edge 26 of the fluid inlet 14 towards the edge of the valve body 12. In the illustrated embodiment, the reinforcing ribs extend radially relative to the fluid inlet axis A. However, the reinforcing ribs may also extend from the inside outwardly in a more spiral manner. In that case, the reinforcing ribs connect the edge 26 of the fluid inlet 14 to the outer edge of the valve body 12. The reinforcing ribs 36, 38 are formed on the lower side of the valve base 24. Thus, the reinforcing ribs 36, 38 do not interfere with the fluid flow passage formed on the inside of the valve body 12, i.e., on the upper side of the valve base 24. As can be seen in the figure, the reinforcing ribs include a first reinforcing rib 36 and a second reinforcing rib 38. The first reinforcing rib 36 is an inner reinforcing rib formed between the edge 26 of the fluid inlet 14 and the bulging portion 32 of the valve base 24. In the illustrated embodiment, the first reinforcing rib 36 connects the edge 26 of the fluid inlet 14 to the bulging portion 32 of the valve base 24. The second reinforcing rib 38 is an outer reinforcing rib that extends between the bulging portion of the valve base 32 and the outer edge of the valve base 24. In the illustrated embodiment, the second reinforcing rib 38 connects the bulging portion 32 of the valve base 24 to the outer edge of the valve base 24. The second reinforcing rib 38 ends at a brim-like shoulder 40 formed on the outer edge of the valve base 24. The shoulder 40 can, for example, comprise at least one step, specifically at least two spaced apart steps, extending around the outer edge of the valve base 24, with the second reinforcing rib 38 merging into the step or into the inner one of the steps, respectively. The one or more steps can, for example, form a ring-like collar that extends around the outer edge of the valve base 24 and provides stability to the valve base 24 .

[0052] As shown in FIG. 2, the exhalation valve 10 further comprises a valve membrane 20 associated with the fluid inlet 14. In the state where it is attached to the exhalation valve 10, the valve membrane 20 has an abutment area, which is formed on its outer edge and presses against the upper side of a support 42 formed on the upper side of the valve body 12. The support 42 extends around the outer edge of the valve body 12 and forms a protrusion that protrudes inward from the outer edge of the valve body 12 towards the side of the valve plenum 18. The support 42 is also formed integrally with the valve body 12, for example in the form of an injection molded part formed in the same injection molding process as the valve body 12. During assembly of the exhalation valve 10, the valve membrane 20 has an outer abutment area that is abutted against the upper side of the support 42 of the valve body 12, so that the valve membrane 20 presses against the edge 26 of the fluid inlet 14 at the abutment area formed in the center and presses against the support 42 at the abutment area formed on the outer side. The leaflets 20 thus define the upper side of the fluid flow passages formed in the valve plenum 18. The leaflets 20 are then clamped against the valve disc 12 using a clamping ring 44, shown in Figure 2. To that end, the clamping ring 44 is placed on the leaflets and then rotated in a bayonet-like manner relative to the valve disc 12. With the clamping force thus created, the leaflets 20 are deformed to a certain degree at their periphery.

[0053] For this reason, the support 42 has a non-uniform shape on its upper side. The bumps thus formed on the surface of the support 42, indicated in FIG. 4 by reference number 46, counteract the deformation of the valve leaflet 20 caused when the clamping ring 44 is clamped against the valve body 12, so that the formation of folds or bows around the valve leaflet 20 in the clamped state can be reduced. In particular, the bumps 46 are formed on the upper side of the support 42 in the form of projections, bulges or ribs spaced apart from one another along the periphery. These bulges or ribs can extend in the radial direction. It is even better when the bulges or ribs have a thread-like design, i.e. have a specific pitch relative to the plane of the abutting valve leaflet 20 and / or extend not only radially but also circumferentially, for example extending helically around the circumference of the valve body 12. In order to limit the clamping forces thus created, it may be advantageous to keep the pitch of the thread formed by the bulges or ribs low and / or also to limit the lift-up, for example, by means of stops at the ends of the bulges or ribs and / or by means of a transition to a portion at the ends of the bulges or ribs that runs parallel to the plane of the valve leaflets 20. In particular, protuberances in the form of bulges and / or ribs may be formed integrally with the support 42.

[0054] The support portion 42 may be formed to extend continuously around the circumference of the outer edge of the valve disc (e.g., as shown by the area labeled 42 in FIG. 4), or may be formed intermittently such that discrete support portions are formed successively disposed along the periphery of the outer edge of the valve disc 12. In the embodiment according to FIG. 4, such discrete support portion 42a is formed on the side of the fluid outlet 16 above the exhaust opening between the valve plenum 18 and the fluid outlet 16.

[0055] The upper side 46 of the support 42 is formed in a non-uniform manner so that the upper side 46 of the support 42 is disposed on an imaginary curved surface, i.e. there is no imaginary plane that completely comprises the upper side 46 of the support 42. The imaginary curved surface covers the upper side of the valve body 12. In particular, the surface is disposed perpendicular to the fluid inlet axis A, which at the same time constitutes the longitudinal axis of the valve body 12. Due to the non-uniform shape of the upper side 46 of the support 42, a planar surface does not contact the entire upper side 46 of the support 42 when attempting to place it on the upper side 46 of the support. Rather, there are only individual places of the planar surface that establish contact with the upper side 46 of the support 42. Thus, in the state of the exhalation valve 10 when the exhalation valve 10 is not installed in the ventilator 100, the planar valve membrane 20 does not abut the upper side 46 of the support 42 over its entire circumference. Rather, there are individual places of contact between the valve membrane 20 and the support along the circumference of the valve membrane 20. The unevenness of the upper side of the support 42 is such that only when the expiratory valve 10 is installed in the ventilation device 100 and the valve body 12 is exposed to stresses that cause its deformation, the upper part 46 of the support 42 lies in a planar plane and the valve membrane 20 has its abutment area in sheet-like contact or complete area contact with the upper side 46 of the support 42.

[0056] The valve body 12 is provided with at least one mounting tab 50 designed for engagement with a bayonet-like exhalation valve connection of the ventilation device 100. The ventilation device is therefore provided with a mating engagement member with which the mounting tab 50 engages during installation of the exhalation valve 10 to hold the exhalation valve 10 in the ventilation device 100. Such a bayonet-type connection has the property that a clamping force is created during the fastening of the exhalation valve 10 to the ventilation device 100, which slightly deforms the valve body 12.

[0057] The valve body 12 has at least two mounting tabs 50 associated with each other. The mounting tabs 50 are arranged on the radial outer circumference of the valve body 12 around the periphery of the valve body 12 and project radially from the respective radially outer edges of the valve body 12 to form respective engagement surfaces 52 with corresponding mating engagement members on the ventilation device 100. When the mounting tabs 50 are engaged with the respective mating engagement members on the ventilation device 100, the valve body 12 is moved towards the ventilation device 100 on the respective side on which the mounting tabs 50 are arranged. During this forced movement, there is a stress created in the valve body 12, and the upper edge 48 of the valve body 12 bends towards the ventilation device 100 on the side on which the mounting tabs 50 are arranged. The uneven design of the upper side 46 of the support 42 on the valve body 12 for the valve membrane 20 is intended to counteract this bending of the valve body 12. When the mounting tabs 50 are engaged with their respective mating engagement members on the ventilator 100, the upper side 46 of the support portion 42 is flat, i.e., placed in a predetermined position. The two mounting tabs 50 are positioned 180° apart from each other, i.e., on either side of the valve body 12 across the valve plenum 18.

[0058] The upper side 46 of the support portion 42 is positioned in an imaginary plane curved outwardly with respect to the valve plenum 18, and covers the upper side of the valve body 12. Specifically, with respect to the valve plenum 18, the outwardly curved imaginary plane is positioned further outward (i.e., to the left and right in FIG. 4 ) than an imaginary plane passing through at least two different positions on the upper side 46 of the support portion 42 on the side where the mounting knobs 50 are present. The upper side 46 of the support portion 42 is positioned in a convexly curved imaginary plane such that a line connecting two positions on the imaginary plane extends through the valve plenum 18. The upper side 46 of the support portion 42 bulges outward starting from the two mounting knobs 50. At the location where the mounting knobs 50 are provided, the upper side 46 of the support part 42 does not bulge outward at all, while it has its greatest outward bulge midway between the two mounting knobs 50 (in FIG. 4, along a vertical line perpendicular to the connection between the two mounting knobs 50). This takes into account the fact that, when the exhalation valve 10 is attached to the ventilator 100, the deformation of the valve body 12 is greatest at the location where the mounting knobs 50 are provided. At this location, the upper edge 48 of the valve body 12 is bent upwards to the greatest extent.

[0059] In the illustrated embodiment, the curved imaginary surface is the side of a cylinder, the axis of which is perpendicular to the connection line between two associated mounting knobs 50 .

[0060] Due to the stresses applied during the installation of the exhalation valve 10 on the valve body 12 at the locations where the mounting knobs 50 are present, the upper edge 48 of the valve body 12 is also bent at these locations towards the opposite side of the ventilator 100. To counteract this effect, it is advantageous to form the valve body 12, or more precisely, the upper edge 48 of the valve body 12, in a manner corresponding to the support 42 for the valve membrane 20. The upper edge 48 of the valve body 12 is to abut against the opposite side of the ventilator 100 over as large an area as possible in order to ensure as close an abutment of the valve membrane 20 as possible during installation of the exhalation valve 10 on the ventilator 100. To this end, the valve body 12 has an upper edge 48 that is arranged in an imaginary plane curved outwardly with respect to the valve plenum 18. The considerations previously given for the upper side 46 of the support 42 apply analogously to the design of the upper edge 48 of the valve body 12. Specifically, the upper edge 48 of the valve disc 12 is disposed in a curved imaginary plane that is convex with respect to the valve plenum 18 and bulges outwardly from at least one mounting tab 50. The bulge of the upper edge 48 of the valve disc 12 is greater in an area located between the two mounting tabs 50 than in an area adjacent one of the two mounting tabs 50.

[0061] The non-uniform shape of the upper side 46 of the support 42 and the non-uniform shape of the upper edge 48 of the valve disc 12 are matched to each other. This makes sense, since the effect achieved by both of these shapes is that when the exhalation valve 10 is installed in the ventilator 100, both the upper side 46 of the support 42 and the upper edge 48 of the valve disc 12 are arranged in a planar surface. In particular, the upper side 46 of the support 42 and the upper edge 48 of the valve disc 12 bulge outwardly in a side-by-side manner with the places of minimum and maximum bulges matching each other, in particular located in the same place relative to the plane covering the valve plenum 18. The design is even such that the upper side 46 of the support 42 and the upper edge 48 of the valve disc 12 have approximately the same bulge, in particular located in imaginary planes parallel to each other.

[0062] Each of the mounting knobs 50 has an engagement surface 52 for engagement with a mating engagement member provided on the ventilation device 100, with a lead-in chamfer 52a on the engagement surface 52 that matches with the upper bulge of the support part 42. As is typical for bayonet-type engagement, the engagement surface 52 will usually be formed substantially parallel to the upper edge of the mounting knob. The engagement surface 52 is provided at its front with a lead-in chamfer 52a. In the region of the lead-in chamfer 52a, the engagement surface 52 therefore extends at an angle, in particular an acute angle, to the upper edge of the mounting knob 50. The angle is selected such that the thickness between the engagement surface 52 and the upper edge of the mounting knob 50 increases with increasing distance from the start of the engagement surface 52a. This allows a certain degree of stress to be created when engaging the mounting knob 50 with the mating engagement member on the ventilation device 100, which promotes a certain pressure fit or frictional engagement, thereby promoting a firm and secure seating arrangement of the exhalation valve 10 on the ventilation device 100. The lead-in chamfer 52a is designed with a bias acting on the upper edge 48 of the valve body on the side of the mounting knob 50, so that a bias is created when the mounting knob 50 is tightened on the ventilation device 100. This is achieved by a certain deformation of the valve body 12 to the side facing the mounting knob 50, relative to the side or location further away from the mounting knob 50. Specifically, the upper edge 48 of the valve body 12 is brought closer to the ventilation device 100 by the movement of the mating engagement member along the lead-in chamfer 52a. On the other hand, the location further away from the mounting knob 50 is already abutting the contact area of ​​the ventilation device 100 and cannot be brought closer. As a result, a deformation of the upper edge 48 of the plug 12 is created that is increasingly directed toward the mounting tab 50. This results in a bias on the plug 12 that increases with increasing travel of the mating engagement member along the lead-in chamfer 52a. The lead-in chamfer 52a is selected such that, upon tightening, a bias is created that is sufficient to cause the upper edge 48 of the plug 12 to be planar in the tightened state, i.e., to be positioned in a plane over the valve plenum 18 in the tightened state. The upper edge 48 of the plug 12 then comes into sheet-like contact with the opposing surface of the ventilator 100.The support part 42 for the valve membrane 20, which is formed integrally with the valve body 12, is equally curved. It is advantageous if the upper side 46 of the support part 42 is uneven to the same extent as the upper edge 48 of the valve body 12, so that the upper side 46 of the support part 42 is flat even when the exhalation valve 10 is mounted on the ventilator 100. The lead-in chamfer 52a of the mounting knob 50 is therefore matched to the bulge of the support part 42.

[0063] In order to define the end of the lead-in chamfer 52a as well as possible and thereby to allow the bias for the valve body 12 to be adjusted as precisely as possible, it can be provided that the engagement surface 52 has a non-tapered portion 52b following the lead-in chamfer 52a. In the non-tapered portion 52b, the engagement surface 52 is parallel to the upper edge of the mounting knob 50. Thus, when the opposing engagement member reaches the non-tapered portion 52b, the bias and bending of the valve body 12 already reached is not changed any more. Thus, the bias and bending can be adjusted in a good reproducible manner, since it is no longer very relevant which part of the non-tapered portion 52b is reached by the mounting knob 50. Furthermore, the engagement surface 52 is provided with a stop 54 at its end, which defines the end of the engagement movement between the mounting knob 50 and the ventilator 100.

[0064] The described exhalation valve 10 can be designed as a single-use component, i.e. in a form that can be used only once and needs to be disposed of after use. Such an exhalation valve is inexpensive to manufacture, but meets the required hygiene standards. Alternatively, the exhalation valve 10 may be designed to allow multiple uses. To that end, the design of the exhalation valve 10 must be such that it can be sterilized after use, for example by autoclaving. To that end, the exhalation valve must be designed to withstand autoclaving. [Explanation of symbols]

[0065] 10 exhalation valve, 12 valve body, 14 fluid inlet, 16 fluid outlet, valve outlet, 18 cup-shaped valve plenum, 20 valve membrane, 22 fluid inlet opening, fluid entry surface, 24 valve base, 26 inner edge, 28 fluid inlet, 30 fluid outlet, 32 bulge, 34 deepest point of passage, 36 first reinforcing rib, 38 second reinforcing rib, 40 shoulder, 42 support, 42a support portion, 44 fastening ring, 46 raised, upper side, 48 upper edge, 50 mounting knob, 52 engagement surface, 52a lead-in chamfer, engagement surface, 52b non-tapered portion, 54 stop, 100 ventilation device, 102 rack, 110 control device, 120 monitoring device, 130 conduit, 132 first ventilation air pipe, 134 humidification device, 136 second ventilation air pipe, 138 T-piece, 140 conduit, 142 breathing air pipe, 150 conduit, A axial direction, fluid inlet axis, B plane in which the valve base extends, C plane in which the valve membrane extends, N normal vector, Tmax maximum depth, Tmin minimum depth, α angle

Claims

1. An exhalation valve (10) for a ventilation device (100), comprising: a valve body (12) having a fluid inlet (14) and a fluid outlet (16) for the patient's breathing air, the valve body (12) defining a fluid flow path between the fluid inlet (14) and the fluid outlet (16); a valve membrane (20) configured to be displaceable between a position for closing the fluid inlet (14) and a position for opening the fluid inlet (14), the valve membrane (20) abutting an edge (26) of the fluid inlet (14) of the valve body (12) to close the fluid inlet (14); In the exhalation valve (10), the valve body (12) is at least partially surrounded by a valve base (24) to define a cup-shaped valve plenum (18) into which the fluid inlet (14) opens; The valve bottom (24) extends in a dish-like manner between the fluid inlet (14) and the outer edge of the valve body (12); the fluid inlet (14) and the valve base (24) have a rounded contour beginning inside the fluid inlet (14) and extending to an outer edge of the valve base (24) facing the cup-shaped valve plenum (18); The valve bottom (24) bulges in the axial direction at a portion around the fluid inlet (14) to form an axial bulge (32) having a different depth around the periphery of the fluid inlet (14), thereby expanding the cross-sectional area of ​​the fluid flow path along a direction toward the fluid outlet (16).

2. 2. The exhalation valve of claim 1, wherein the depth of the axial bulge (32) increases in a circumferential direction toward the fluid outlet (16).

3. 3. The exhalation valve according to claim 1 or 2, wherein the depth of the axial bulge (32) in the circumferential direction is smallest on the side opposite the fluid outlet (16).

4. 4. The exhalation valve according to claim 1, wherein the depth of the axial bulge (32) in the circumferential direction is greatest on the side towards the fluid outlet (16).

5. The exhalation valve according to any one of claims 1 to 4, wherein the fluid inlet (14) is disposed in a central portion of the cup-shaped valve plenum (18).

6. 6. The exhalation valve according to any one of claims 1 to 5, wherein the fluid outlet (16) is disposed further outwardly with respect to the fluid inlet (14).

7. The exhalation valve according to any one of claims 1 to 6, wherein the valve body (12) is made of a plastic material.

8. 8. The exhalation valve according to claim 7, wherein the valve body (12) is an injection molded part.

9. 9. The exhalation valve according to claim 1, wherein the valve body (12) has a fluid inlet portion (28) in which the fluid inlet (14) is formed.

10. 10. The exhalation valve of claim 9, wherein the fluid inlet portion (28) defines a first pin-like protrusion.

11. The exhalation valve according to any one of claims 1 to 10, wherein the valve body (12) has at least one reinforcing rib formed around the fluid inlet (14).

12. 12. The exhalation valve according to claim 11, wherein at least one of the reinforcing ribs (36, 38) is integrally formed with the valve body (12).

13. 13. The exhalation valve of claim 12, wherein at least one of the reinforcing ribs (36, 38) extends in an outward direction relative to the edge (26) of the fluid inlet (14).

14. 14. The exhalation valve according to any one of claims 11 to 13, wherein the at least one reinforcing rib comprises at least one first reinforcing rib (36) extending from the edge (26) of the fluid inlet (14) along the valve bottom (24).

15. 15. The exhalation valve according to any one of claims 11 to 14, wherein the at least one reinforcing rib comprises at least one second reinforcing rib (38) extending along the valve base (24) inwardly from an outer edge of the valve base (24).

16. 16. The exhalation valve according to any one of claims 1 to 15, wherein the valve body (12) defines a fluid outlet portion (30) in which the fluid outlet (16) is formed.

17. 17. The exhalation valve of claim 16, wherein the axial bulge (32) of the valve base (24) merges with the fluid outlet (30).

18. 18. The exhalation valve according to claim 17, wherein the valve body (12) further comprises a support (42) on the upper side of which the valve membrane (20) rests with an abutment area formed at the outer edge of the valve membrane (20), and the support (42) is formed non-flat on its upper side.

19. The exhalation valve according to any one of the preceding claims, wherein the valve body (12) comprises a plurality of reinforcing ribs formed around the fluid inlet (14).

20. 20. A ventilation device comprising an exhalation valve according to any one of claims 1 to 19 adapted to be connected to an exhalation air conduit (140).

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