valve

Abstract

The present disclosure relates to a valve (20) for use with respiratory assistance equipment. The valve includes a valve body (25) defining first, second and third ports (21, 22, 23) and a valve core (27) defining a ported chamber (40), the ported chamber (40) having a first stable configuration in which the ported chamber provides fluid communication between the first and second ports and separates the third port from the first and second ports, and a second stable configuration in which the ported chamber provides fluid communication between the first and third ports and separates the third port from the first and second ports. a valve core (27) rotatable about a valve axis (28) between a first stable configuration separating a second port from a second stable configuration, an outer surface (34) of the valve core configured to engage an inner surface (32) of the valve body to define a detent that resists rotation of the valve core between the first stable configuration and the second stable configuration, and an actuator (30) configured to overcome the detent to rotate the valve core between the first stable configuration and the second stable configuration.

Description

[Technical field]

[0001] The present disclosure relates to a two-way valve for use with respiratory assistance devices and patient ventilator systems. [Background technology]

[0002] Critically ill patients often require artificial ventilation to assist or replace spontaneous breathing. This can be provided manually or via a mechanical ventilation system. Mechanical ventilation is called "invasive" if it involves some instrument penetrating the mouth or skin. The two main modes of mechanical ventilation are positive pressure ventilation, where air (or other gas mixture) is forced into the trachea, and negative pressure ventilation, where air is drawn into the lungs, for example, by applying subatmospheric pressure against the outer chest wall.

[0003] A patient may need to be temporarily disconnected from the breathing circuit and ventilator for a number of reasons, e.g., (i) to change the ventilator, e.g., to a portable ventilator for intra-hospital and inter-hospital transport, (ii) to manually ventilate the patient, e.g., using a water circuit, to improve oxygen saturation, (iii) to change the breathing circuit, (iv) to move or reposition the patient.

[0004] Several problems can arise in connection with disconnecting the breathing circuit.

[0005] The first potential problem concerns staff safety: when the breathing circuit is disconnected, potentially infected aerosols of secretions and water within the breathing circuit can be released into the room (potentially under pressure) and can spray attending clinical or medical staff during the temporary disconnection of a ventilated patient from the breathing circuit.

[0006] A second potential problem concerns patient safety. When a breathing circuit is vented to the atmosphere, a vacuum is created and the patient's lungs lose positive end-expiratory pressure (PEEP). PEEP is necessary to prevent the collapse of alveoli in the patient's lungs during ventilation. When alveoli collapse, the oxygen level in the blood falls and the collapsed alveoli can become susceptible to infection. Re-inflating the alveoli can be difficult. In patients with severe lung disease, it is not uncommon for oxygen saturation to drop dangerously rapidly within seconds of the breathing circuit being disconnected. Historically, loss of PEEP during disconnection of the breathing circuit has been mitigated by applying a clamp to the endotracheal tube before and during disconnection, but this technique may have contraindications. If the patient makes an inspiratory effort while the clamp is applied, the negative pressure generated can lead to life-threatening complications. Summary of the Invention

[0007] It is an object of the present invention to provide an improved method and apparatus for alleviating some or all of the above problems.

[0008] According to a first aspect of the present disclosure, there is provided a valve, the valve comprising: a valve body defining first, second and third ports; A valve core defining a ported chamber, the ported chamber comprising: a first stable configuration, wherein the ported chamber provides fluid communication between the first port and the second port and separates the third port from the first and second ports; the ported chamber is rotatable about the valve axis between a second stable configuration providing fluid communication between the first port and the third port and isolating the second port from the first and third ports; a valve core, an outer surface of the valve core configured to engage an inner surface of the valve body to define a detent that resists rotation of the valve core between the first stable configuration and the second stable configuration; and an actuator configured to overcome the detent to rotate the valve core between the first stable configuration and the second stable configuration.

[0009] The actuator may be configured to transition between two stable configurations and to prevent the valve core and valve body from maintaining a stable intermediate position between the first stable configuration and the second stable configuration.

[0010] The valve may comprise a biasing element configured to exert a biasing force to press an outer surface of the valve core and an inner surface of the valve body together. The biasing element may be configured to exert a biasing force along the valve axis. Exerting a biasing force along the valve axis may mean that at least a component of the force is provided along the valve axis, including cases where a substantial component is provided along the valve axis and where the entire force is aligned with the valve axis. The biasing element may comprise a spring.

[0011] The actuator may be configured to facilitate applying a rotational force to the valve core about the valve axis.

[0012] The actuator may be configured to overcome the detents and biasing forces to rotate the valve core about the valve axis between the first and second stable configurations. The actuator may be configured to overcome the detents and biasing forces to displace the valve core along the valve axis away from the inner surface of the valve body.

[0013] A greater percentage of the inner surface of the valve body and the outer surface of the valve core may be in contact between the first and second stable configurations than between intermediate positions between the first and second stable configurations.

[0014] The valve core may include a tapered portion defining the ported chamber. The second end of the tapered portion may be narrower than the first end of the tapered portion. The valve body may include a tapered portion for receiving the tapered portion of the valve core. The valve core may be substantially frusto-conical.

[0015] The valve core may include one or more sealing portions on an outer surface of the valve core. The one or more sealing portions may be configured to provide a seal between the valve core and the first, second and third ports.

[0016] The outer surface of the valve core may be substantially transverse or substantially perpendicular to the valve axis.The inner surface of the valve body may be substantially transverse or substantially perpendicular to the valve axis.The outer surface of the valve core may face the inner surface of the valve body.

[0017] The outer surface of the valve core and the inner surface of the valve body may each include one or more corresponding detent features configured to engage with one another to define a detent.

[0018] The outer surface of the valve core and the inner surface of the valve body may each include a contoured surface. The contoured surfaces may provide a pair of mating surfaces.

[0019] Each contoured surface may comprise a repeating substantially sinusoidal or triangular profile extending around the valve axis.

[0020] Each contoured surface may include a series of peaks and valleys, or hills and depressions, extending around the valve axis. The peak of each peak and the base of each valley may extend laterally or radially from the valve axis.

[0021] At least one of the contoured surfaces may be formed as a plurality of concentric rings about the valve stem.

[0022] The outer surface of the valve core and the inner surface of the valve body may be provided with two corresponding cam surface profiles.

[0023] The outer surface of the valve core and the inner surface of the valve body may each have 90 degree rotational symmetry about the valve axis.

[0024] The detent may include a first range of rotation and a second range of rotation between the first and second stable configurations. The detent may bias the valve core toward the first stable configuration when the valve core is within the first range of rotation. The detent may bias the valve core toward the second stable configuration when the valve core is within the second range of rotation.

[0025] The actuator may comprise a lever rotatable about the valve stem and coupled to the valve core.

[0026] The valve body may further comprise a cap surrounding a first end of the valve body, the cap comprising first and second stops for blocking rotation of the lever and valve core beyond their respective first and second stable configurations.

[0027] The valve core may be displaceable or slidable along the valve axis relative to the valve body and lever.

[0028] The valve may be particularly suitable for use with respiratory support equipment, breathing aids, and / or patient ventilator systems, which may be used interchangeably herein. The first port may be configured for connection to a patient airway. The second and third ports may each be configured for connection to a ventilator breathing circuit or a respiratory support device. The first port may have a 22mm tapered outer diameter connector face. The second and third ports may each have a 22mm tapered inner diameter connector face.

[0029] The valve as described above may further include a ventilation device coupleable to at least one of the second and third ports. The valve as described above may further include an endotracheal tube coupleable to the first port.

[0030] According to a second aspect of the present disclosure, there is provided a method of configuring respiratory assistance equipment for a patient, the method comprising: providing a valve comprising: a valve body defining first, second and third ports; a core defining a ported chamber, the ported chamber rotatable about a valve axis between a first stable configuration, the ported chamber providing fluid communication between the first port and the second port and isolating the third port, and a second stable configuration, the ported chamber providing fluid communication between the first port and the third port and isolating the second port, an outer surface of the core configured to engage an inner surface of the valve body to define a detent that resists rotation of the core between the first and second stable configurations; and an actuator configured to overcome the detent to rotate the core between the first and second stable configurations; coupling a patient respiratory tube to the first port; coupling a first ventilator to a second port; coupling a second ventilator to a third port while the valve is in the first stable configuration; Switching the valve to a second stable configuration; and disconnecting the first ventilator from the second port.

[0031] A valve is also disclosed, the valve comprising: first, second and third ports; a bistable valve mechanism having (i) a first stable configuration, in which a first port is in fluid communication with a second port and is not in fluid communication with a third port, and (ii) a second stable configuration, in which the first port is in fluid communication with a third port and is not in fluid communication with the second port; and an actuator configured to transition the bistable valve mechanism between two stable configurations and prevent the valve mechanism from maintaining a stable intermediate position between the first and second stable configurations. Various aspects of the valve are further described herein.

[0032] Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0033] [Figure 1] FIG. 1 shows a schematic diagram of a three-port connector for use with patient respiratory support equipment. [Figure 2A] FIG. 1 shows a perspective view of a three-port bistable valve for use with patient respiratory support equipment. [Figure 2B] 2B shows a cross-sectional view of the three-port bistable valve of FIG. 2A. [Figure 2C] 2B shows a perspective cutaway view of the three-port bistable valve of FIG. 2A. [Figure 3A] FIG. 2B shows a perspective view of the bistable valve of FIG. 2A in a first stable configuration. [Figure 3B] 2B shows a cross-sectional view of the bistable valve of FIG. 2A in a first stable configuration. [Figure 3C] FIG. 2B shows a perspective view of the bistable valve of FIG. 2A in a second stable configuration. [Figure 3D] 2B shows a cross-sectional view of the bistable valve of FIG. 2A in a second stable configuration. [Figure 3E] 2B illustrates a cross-sectional view of the bistable valve of FIG. 2A in transition between a first stable configuration and a second stable configuration. [Figure 4A] FIG. 2B is an exploded perspective side and top view of the bistable valve of FIG. 2A. [Figure 4B] FIG. 2B is an exploded side and bottom perspective view of the bistable valve of FIG. 2A. [Diagram 5] FIG. 2B is an exploded cross-sectional schematic diagram of the valve of FIG. 2A useful for illustrating features of the bistable mechanism. [Figure 6A] FIG. 13 is an exploded side and top perspective view of another three-port bistable valve for use with patient respiratory assistance equipment. [Figure 6B] FIG. 13 is an exploded side and bottom perspective view of another three-port bistable valve for use with patient respiratory assistance equipment. [Figure 6C] FIG. 6D is a perspective view showing the inner surface of the housing of the valve of FIGS. 6A and 6C. [Figure 7A] FIG. 13 is an exploded side and top perspective view of a further three-port bistable valve for use with patient respiratory assistance equipment. [Figure 7B]FIG. 13 is an exploded side and bottom perspective view of a further three-port bistable valve for use with patient respiratory assistance equipment. [Figure 7C] FIG. 7D is a perspective view showing the inner surface of the housing of the valve of FIGS. 7A and 7C. [Figure 7D] FIG. 7B is a cross-sectional view of the exploded perspective view shown in FIG. 7A. [Figure 7E] FIG. 7E is a cross-sectional view of the assembled valve shown in FIG. 7D. [Figure 7F] FIG. 7B is a perspective view of the valve core of FIGS. 7A-7D. [Figure 7G] FIG. 7B is a perspective view of the valve core of FIGS. 7A-7D. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] Throughout this specification, relative orientation and positional descriptors such as "top," "bottom," "horizontal," "vertical," "left," "right," "upper," "lower," "front," "rear," and their adjectival and adverbial derivatives are used in reference to the orientation of the valve as shown in the drawings. However, such descriptors are not intended to limit in any manner the intended use of the invention as described or claimed. The terms "clockwise" and "counterclockwise" are used herein in reference to orientations as viewed from above the valve for purposes of illustration and description of the particular embodiments as shown in the drawings, and are not intended to be limiting to those particular embodiments.

[0035] Figure 1 shows a practical use of a patient ventilator system. As seen in Figure 1a, a patient 1 is provided with a breathing tube, such as an endotracheal tube 2, placed through the mouth into the trachea to supply oxygen and / or other gases to the lungs. In this specification, the invention is described in relation to an endotracheal tube 2, but other forms of breathing tubes, such as a tracheotomy tube, may also be applicable to the invention. A closed suction device 3 connects the patient to a ventilator breathing circuit 4. In situations such as those discussed above, it may be desirable to facilitate connecting the patient 1 to an alternative ventilation device, such as a ventilation bag 6 (Figures 1c and 1d). This may be achieved using a T-valve 5, as seen in Figure 1b, having a first branch 11 connected to the patient breathing tube 2 (via the suction device 3), a second branch 12 connected to the ventilator breathing circuit 4, and a third branch 13 suitable for connection to a further ventilation device. In FIG. 1b, the T-valve 5 has the valve mechanism rotated to a first configuration in which the first branch 11 is fluidly coupled to the second branch 12 by a first fluid passage and the third branch 13 is isolated from the first fluid passage between the first branch 11 and the second branch 12.

[0036] As can be seen in FIG. 1 c , an alternative ventilation device 6 is coupled to the third branch 13 while the valve mechanism remains in the first configuration coupling the first branch 11 and the second branch 12 .

[0037] As seen in Figure 1d, the valve mechanism is then rotated to a second configuration in which the first branch 11 is fluidly coupled to the third branch 13 by a second fluid passageway and the second branch 12 is isolated from the second fluid passageway between the first branch 11 and the third branch 13. In this configuration, the ventilator breathing circuit 4 is then disconnected as seen in Figure 1d. This disconnection occurs after the patient's airway is connected to the third branch 13 of the T-valve and thus to the alternative ventilator 6 and isolated from the ventilator breathing circuit 4.

[0038] In one aspect, a valve suitable for implementation in the context of Figures 1a-1d may have a mechanism whereby the transition from the first configuration to the second configuration occurs quickly, such that the valve does not remain in an intermediate position between the first and second configurations for an appreciable period of time. The expression "intermediate position" may encompass positions where fluid communication between the first branch 11, the second branch 12 and the third branch 13 may coexist simultaneously, or positions where there is no fluid communication between any of the first branch 11, the second branch 12 and the third branch 13 (the fluid path between each of the first, second and third branches is blocked). The expression "appreciable length of time" may be understood as relative to normal pressure changes in the patient's airway. In another aspect, a valve suitable for implementation in the context of Figures 1a-1d may have a mechanism whereby the user cannot place or leave the valve unmoved in such an intermediate position.

[0039] A first exemplary valve 20 suitable for the above purpose is described with reference to Figures 2A to 5. With reference to Figure 4A, the valve 20 has a first end (top of the figure) and a second end (bottom of the figure). The valve comprises an operating level 30, a valve cap 26, a valve core 27, and a valve body 25. The operating level 30 is provided in this example at the first end and the valve body 25 is provided at the second end.

[0040] Valve body 25 defines three ports 21, 22, 23 that extend radially outward from a cylindrical core portion 24 of valve body 25. In this example, valve cap 26 and body 25 enclose a valve core 27 within core portion 24 of body 25. Cap 26 may be sealed to valve body 25 via welding or other suitable processes known in the art.

[0041] The valve core 27 is rotatably mounted within the core portion 24 and is rotatable about a valve axis 28 that extends between the first and second ends of the valve 20. As best seen with reference to Figures 4A and 4B, the valve core 27 defines a ported chamber 40 having openings 41, 42, 43 at 0, 180 and 90 degree positions relative to one another about the valve axis 28, respectively. These openings 41, 42, 43 are positioned to generally align with selected ones of the ports 21, 22, 23 when at particular angular positions within the valve body 25, as discussed below. For example, in a first stable configuration, the ported chamber 40 can provide fluid communication between the first port 21 and the second port 22 via the second opening 43 and the first opening 41. In the second stable configuration, the ported chamber 40 can provide fluid communication between the first port 21 and the third port 23 via the first opening 41 and the third opening 42 .

[0042] Also visible in Figure 4a is a central shaft of the valve core 27 that extends along the valve axis 28. In this example, the central shaft is discontinuous. A first portion of the central shaft 44 is provided on a first surface of the valve core 27 (facing the first end of the valve 20) and a second portion of the central portion 34 is provided on an opposing second surface of the valve core 27 (facing the second end of the valve).

[0043] A first portion of the central shaft 44 extends axially through an opening 29 in the cap 26 to engage the operating lever 30 when the valve core 27 is installed in the body 25. The operating lever 30 is rotatable about the valve axis 28 and extends radially outward from the cap 26. The first portion of the shaft 44 is slidably rotatable within the opening 29 such that the operating lever 30 is rotatable about the valve axis 28 relative to the cap 26 and the valve body 25. In the arrangement shown, the movement of the operating lever 30 is limited to an arc of approximately 90 degrees by stops 36a, 36b formed on the outer surface of the cap 26. The operating lever 30 is rotatably coupled to the valve core 27 such that rotation of the operating lever 30 also rotates the valve core 27. In this example, the operating lever 30 has a groove 45 for receiving the first portion of the shaft 44, as best seen in Figures 2B and 2C. The first portion of the shaft 44 has a chamfered edge 44a and the groove 45 has a corresponding profile to provide a rotatable engagement between the operating lever 30 and the valve core 27. In other examples (see, for example, FIG. 6), the valve core 27 may include a groove or slot instead of a shaft, and the operating lever 30 may include an engagement shaft for coupling to the groove to provide a rotatable coupling. The operating lever 30 may include a directional indicator 30a that indicates the current configuration of the valve 20. In this example, the directional indicator 30a includes an arrow pointing towards a port that is not in fluid communication with the first port.

[0044] The valve core 27 is rotatably connected to the operating lever 30, but is axially slidably connected to the operating lever 30 (and the valve body 25 and cap 26) so that the valve core 27 can be slidably displaced along the valve axis 28 relative to the valve body 25, cap 26, and operating lever 30.

[0045] An outer surface of the valve core 27 is provided facing the inner surface of the valve body 25 at the second end of the valve. The outer surface of the valve core 27 includes a detent feature in the form of an undulating surface 34 (FIG. 4B). In this example, the undulating surface 34 includes a repeating triangular profile (or a sloped profile) that extends around the valve axis 28. In other examples, the undulating surface 34 may include a substantially sinusoidal profile that extends around the valve axis. More generally, each undulating surface may include a series of peaks and valleys, or hills and depressions, that extend around the valve axis. The peak of each peak and the base of each valley may extend radially from the valve axis.

[0046] The inner surface of the valve body 25 is provided with a corresponding undulating surface 32 such that the undulating surfaces 32, 34 can interlock together. Thus, the outer surface 34 of the valve core 27 is configured to engage with the inner surface 32 of the valve body 25 to define a detent. The detent resists rotation of the valve core 27 between the first and second stable configurations. Both undulating surfaces 32, 34 have a 90-degree rotational symmetry about the valve axis 28. As a result, the two undulating surfaces 32, 34 include four positions where they fully engage or interlock. Two of these positions define the first and second stable configurations. In other words, the outer surface 34 of the valve core 27 is fully engaged with the inner surface 32 of the valve body 25 when the valve 20 is in the first and second stable configurations. In this example, full engagement corresponds to the peaks of the triangular profile of the outer surface 34 of the valve core 32 nesting within the valleys of the triangular profile of the inner surface 32 of the valve body 25, and vice versa. In some examples, the resistance strength of the detents may be adjusted by selecting the slope angle / magnitude of the undulating profiles 32, 34.

[0047] In this example, the second portion of the central shaft 46 extends from the outer surface of the valve core 27. The second portion of the central shaft 46 engages a corresponding recess or opening 48 in the surface of the valve body 25. The second portion of the central shaft 46 can slidably rotate within the opening 48 as the valve core 27 rotates within the valve body 25 about the valve axis 28. The first and second shaft portions 44, 46 can provide stable rotation of the valve core 27 within the valve body and can prevent radial displacement of the valve core 27. It will be appreciated that in other examples, stable rotation of the valve core 27 within the valve body 25 about the valve axis 28 can be provided in other manners, for example, by a single shaft extending through the valve core 27, or by a central groove in the first and / or second surface of the valve core 27 that appropriately engages with a corresponding shaft on the inner surface of the operating lever 30 and / or the valve body 25. However, all arrangements may provide a slidable axial connection that allows axial displacement of the valve core 27 relative to the valve body 25 , cap 26 and operating lever 30 .

[0048] In this example, the valve 20 further comprises a biasing element 49 in the form of a spring positioned between the cap 26 and the valve core 27. The spring may be provided by a metal, rubber, or plastic material. When the valve is assembled, the biasing element 49 exerts a biasing force on the valve core 27, promoting engagement between the outer surface 34 of the valve core 27 and the inner surface 32 of the valve body 25. In other words, the biasing element 49 pushes the valve core towards the valve body 25. As a result, the biasing element 49 can increase the strength of the detent in resisting rotation of the valve core 27 between the two stable configurations. The biasing force of the biasing element 49 may be selected based on the desired detent resistance.

[0049] In this example, the core 27 / ported chamber is tapered such that the second end of the core 27 is narrower than the first end of the core 27 (as best seen in FIG. 2B ). In this example, the cylindrical portion 24 of the valve body 25 is also tapered. Thus, the core 27 is substantially frusto-conical. As discussed below, the tapered profile of the core 27 and valve body 25 may facilitate sealing between the openings 41, 42, 43 and the ports 21, 22, 23 when the valve is in the first and second stable configurations, and may reduce friction on the sealing surfaces to facilitate rotation when the core is positioned between the first and second configurations.

[0050] Figures 3A and 3B show the valve 20 in a first configuration, and Figures 3C and 3D show the valve 20 in a second configuration. In Figures 3A and 3B, the second opening 43 is aligned with the first port 21 and the first opening 41 is aligned with the second port 22, so that the valve 20 is in a first stable configuration in which the first port 21 is in fluid communication with the second port 22 through the ported chamber 40 of the valve core 27. The third opening 42 is occluded by the wall of the valve body 25. It can also be seen that the third port 23 is blocked or occluded by the valve core 27 and is therefore not in fluid communication with either the first port or the second port.

[0051] 3C and 3D, the first opening 41 is aligned with the first port 21 and the third opening 42 is aligned with the third port 23, so that the valve 20 is in a second stable configuration in which the first port 21 is in fluid communication with the third port 23 through the ported chamber 40 of the valve core 27. The second opening 43 is occluded by the wall of the valve body 25. It can also be seen that the second port 22 is blocked or occluded by the valve core 27 and is therefore not in fluid communication with either the first port or the third port. From this figure, it can be seen that when transitioning from the configuration of Figure 3A / 3B to the configuration of Figure 3C / 3D, when performing a quarter counterclockwise rotation of the valve core 27, depending on the diameters of the openings 41-43 and ports 21-23, and depending on the circumference of the valve core 27 / cylindrical core portion 24, the valve 20 can be configured as a "break-before-make" type valve in which fluid flow from one port pair is completely blocked before communication of the other fluid pair begins to be made, or vice versa ("make-before-break").

[0052] Now also referring to FIG. 3E, the operation of the valve will be explained.

[0053] Initially, the valve 20 is in a first stable configuration in FIGS. 3A and 3B with the operating lever 30 aligned with the third port 23, the third port 23 isolated, and the first port 21 in fluid communication with the second port 22. The contoured outer surface 34 of the valve core 27 is fully engaged with the corresponding contoured inner surface 32 of the valve body 25. As a result, the valve core is in a position closest to the inner surface 32 within the valve body 25. The tapered profile of the valve core 27 can fit snugly with the tapered profile of the valve body to provide a hermetic seal between the first port 21 and the second opening 43 and between the second port 22 and the first opening 41. The biasing element 49 provides a biasing force to maintain the valve core 27 in this first stable configuration in the absence of any force applied to the lever 30.

[0054] 3A and 3B, the operating lever 30 is moved in a clockwise direction. A force is applied to the operating lever 30 (rotatably coupled to the valve core 27) that overcomes the biasing force of the biasing element 49 and the detent formed by the engagement of the undulating surface 34 of the valve core 27 with the undulating surface 32 of the valve body 25. The valve core 27 rotates counterclockwise around the valve axis 28 in the valve body 25. As the valve core 27 rotates, the undulating surfaces 32, 34 move out of full engagement and the valve core 27 is axially displaced along the valve axis 28 towards the cap 26 against the biasing force of the biasing element 49. The peaks of the triangular profile of the undulating surface 34 of the valve core 27 move away from the valleys and towards the peaks of the undulating surface 32 of the valve body 25. As the valve core 27 lifts (displaces axially) towards the cap 26, the valve core 27 is pulled away from the inner sidewall surface of the cylindrical portion 24 by the tapered profile. As a result, the seals between the openings 41, 42, 43 and the ports 21, 22, 23 are broken. The removal of the seals and "snug fit" of the core 27 within the valve body 25 facilitates rotation of the core 27 due to reduced friction between the core 27 and the valve body 25.

[0055] During a first range of rotation of the valve core 27, when the peaks of the two triangular surface profiles 32, 34 approach each other, the detents and the biasing element urge the valve core 27 towards the first stable configuration. In other words, when the rotational force is removed from the operating lever 30, the valve core rotates rapidly back towards the first stable configuration. During a second range of rotation of the valve core 27, when the peaks of the two triangular surface profiles pass each other, the detents and the biasing element urge the valve core 27 towards the second stable configuration. Thus, when the valve core rotates beyond the first range of rotation (and the valve core 27 reaches its top axial position) and the detents are overcome (the triangular peaks are passed), the valve core 27 rotates rapidly towards the second stable configuration due to both the biasing force and the detents.

[0056] When the valve core 27 reaches the second stable configuration (FIGS. 3C and 3D), it is displaced axially away from the cap 26 and the undulating surface 34 of the valve core 27 fully re-engages with the undulating surface 32 of the valve body 25 as prompted by the biasing force. A snug fit is re-formed between the valve core 27 and the valve body 25. The first opening 41 may hermetically seal with the first port 41 and the third opening 42 may hermetically seal with the third port 23. The operating lever 30 is aligned with the second port 22 indicating that the second port 22 is isolated and the first port 21 is in fluid communication with the third port 23. Further rotation of the operating lever 30 is prevented by the stop 36b on the cap 26.

[0057] Corresponding reverse movement of the operating lever 30 approximately 90 degrees clockwise from the position of Figures 3C and 3D provides corresponding reverse rotational movement of the valve core 27 from the second stable configuration of Figures 3C, 3D back to the first stable configuration of Figures 3A, 3B.

[0058] Thus, the valve 20 illustrates a bistable valve mechanism comprising a valve core 27 defining a ported chamber 40 that is rotatable within the valve body 25 about a valve axis 28 between (i) a first stable configuration in which the ported chamber 40 provides fluid communication between the first port 21 and the second port 22 of the valve body and isolates the third port 23, and (ii) a second stable configuration in which the ported chamber 40 provides fluid communication between the first port 21 and the third port 23 of the valve body 25 and isolates the second port 22, with an outer surface 34 of the valve core 27 configured to engage an inner surface 32 of the valve body 25 to define a detent that resists rotation of the valve core 27 between the first and second stable configurations. Additionally, the operating lever 30 and associated features illustrate an actuator configured to overcome the detent to rotate the valve core between the first and second stable configurations. The term "fluid communication" is intended to encompass a configuration in which the flow of air or other gas between communication ports 21, 22 or 23 via valve core 27 is in sufficient quantity and sufficiently unimpeded to have little or no effect on the operation of the breathing circuit which supplies gas to the patient's lungs via the breathing tube.

[0059] Various modifications and adaptations may be made to valve 20 as described above. Figures 6A-6C show a second exemplary valve 120 suitable for the purposes described in connection with Figure 1. Valve 120 includes substantially the same arrangement and operation as the five-part valve of Figures 2-5. The above description of valve 20 applies equally to valve 120, except for certain features described herein in connection with Figures 6A-6C.

[0060] In this example, the valve core 127 further comprises a sealing portion 127a for improving the seal between the ports 121, 122, 123 and the ported chamber 140 when the valve core 127 is in the first and second stable configurations. When the valve core 127 is axially displaced towards the cap 126 while the valve core 127 is rotating between the two stable configurations, the valve core 127 and the sealing portion 127a are pulled away from the inner sidewall of the valve body to reduce friction and facilitate rapid rotation towards the first or second stable configuration. The sealing portion may comprise a flexible or compressible material, such as rubber or elastomer.

[0061] In this example, the detent is also provided by a contoured outer surface 134 of the valve core 127 that engages the contoured inner surface 132 of the valve body 125. In this example, the two contoured surfaces 132, 134 comprise a repeating sinusoidally tapered profile that extends around the valve stem 128. In this example, the contoured outer surface 134 of the valve core 127 is formed as a plurality of concentric rings each having an aligned sinusoidally tapered profile around the valve stem. The use of a concentric profile as shown can reduce the total material required for manufacture, reducing costs and waste.

[0062] The valve 120 of Figures 6A-6C also differs from the valve of Figures 2-5 in the coupling arrangement between the operating lever 130, the cap 126, and the valve core 127. However, the basic principle remains the same: the operating lever 130 is rotatably engaged with the valve core 127, and both components rotate together about the valve axis 128. The operating lever 130 and the valve core 127 are slidably coupled to the cap 126, and both components can rotate relative to the cap 126. This coupling arrangement also allows axial displacement of the valve core 127 along the valve axis 128 relative to the valve body 125, the cap 126, and the operating lever 130.

[0063] The operating lever 130 includes a side wall 131 and a plurality of first clip portions 131a protruding from a surface of the operating lever 130. The cap 126 includes a corresponding receiving wall 126a and a corresponding plurality of second clip portions 126b protruding from the cap 126. The side wall 131 of the operating lever 130 can fit over the receiving wall 126a of the cap 126. The first clip portion 131a can slidably engage with the second clip portion 126b to secure the operating lever to the cap 126 while allowing relative rotation about the valve stem 128 and preventing relative radial displacement.

[0064] The operating lever 130 further comprises a central shaft 130b. The shaft 130b comprises two side flanges 130c extending radially therefrom and defining a keyed cross section. The valve core 127 comprises a corresponding center 144 having a slot 144b for engaging with the operating lever's central shaft 130b. The keyed cross section of the shaft 130b can rotatably engage with the slot 144b of the valve core's central shaft 144 to provide a rotatable coupling between the operating lever 130 and the valve core 127.

[0065] Although both valves 20 and 120 are illustrated as having five components, in other examples valves 20 and 120 may include more or fewer components. For example, a valve core may include a first subcomponent that defines a detent surface 34, 134 and a second subcomponent that defines a ported chamber.

[0066] Figures 7A-7G show a third exemplary valve 220 suitable for the purposes described in connection with Figure 1. Valve 220 includes substantially the same arrangement and operation as the five valves of Figures 2-5. The above description of valve 20 applies equally to valve 220, except for certain features described herein in connection with Figures 7A-7G.

[0067] In this example, the valve core 227 further comprises a sealing portion 227a for improving the seal between the ports 221, 222, 223 and the ported chamber 240 when the valve core 227 is in the first and second stable configurations (in the same manner as the valve of Figs. 6A-6C). When the valve core 227 is axially displaced towards the cap 226 while the valve core 227 is rotating between the two stable configurations, the valve core 227 and the sealing portion 227a are pulled away from the inner sidewall of the valve body 225 to reduce friction and facilitate rapid rotation towards the first or second stable configuration. The sealing portion 227a may comprise a flexible or compressible material such as a rubber or elastomer. In this example, the flexible material covers the entire conical surface of the ported chamber 240, and the sealing portion 227a comprises a ridge of flexible material extending around the openings 241, 242, 243 of the ported chamber 240.

[0068] In this example, the detents are also provided by a contoured outer surface 234 of the valve core 227 that engages a contoured inner surface 232 of the valve body 225. In this example, the two contoured surfaces 232, 234 comprise a repeating triangular slope profile that extends around the valve axis 228. In this example, the contoured outer surface 234 of the valve core 227 comprises flattened peaks 234a and recessed or etched depressions 234b. Similarly, the contoured surface 232 of the valve body 225 includes flattened peaks 232a and etched depressions 232b that engage the respective etched depressions 234b and flattened peaks 234a on the contoured outer surface 234. These additional features may increase the strength of the detents and / or the stability of the first and second stable configurations.

[0069] The valve 220 of Figures 7A-7G also differs from the valve of Figures 2-5 by including a cap seal portion 250. The cap seal portion 250 provides an additional seal to the cap 226 to prevent air leakage at the interface between the cap and the central shaft 244. The cap seal portion 250 also provides a seal between the cap 226 and the air space within the valve body 225 above the valve core 227. In this example, the cap seal portion 250 includes an opening for receiving the central shaft 244 therethrough. The opening is formed of a flexible material, such as rubber or elastomer, to provide an airtight seal. A washer 251 is positioned between the cap seal portion 250 and the biasing element 249 and provides an engagement interface between the cap seal portion 250 and the biasing element 249.

[0070] The valve 220 of Figures 7A-7G also differs from the valve of Figures 2-5 by including a two-part core 227 (best shown in Figures 7F and 7G). In this example, the core 227 includes a first core component 227b that defines a detent surface 234 and a second core component 227c that defines a ported chamber 240 and central shafts 244, 246. The first core component 227b includes a dowel 227d for engaging a corresponding dowel opening 227e on the second core component 227c.

[0071] The valve 220 of Figures 7A-7C also differs from the valve of Figures 2-5 in the coupling arrangement between the operating lever 230, the cap 226, and the valve core 227. However, the basic principle remains the same: the operating lever 230 is rotatably engaged with the valve core 227, and both components rotate together about the valve axis 228. The operating lever 230 and the valve core 227 are slidably coupled to the cap 226, and both components can rotate relative to the cap 226. The coupling arrangement also allows axial displacement of the valve core 227 along the valve axis 228 relative to the valve body 225, the cap 226, and the operating lever 230. This is best shown in FIG. 7E, where the height of the central channel 230d of the operating lever 230 is large enough to allow axial displacement of the central shaft 244 within the central channel 230d as the valve core 227 rotates between the first and second stable configurations and is displaced axially towards the cap 226 and then back again.

[0072] The operating lever 230 includes a side wall 231 and a plurality of first clip portions 231a protruding from a surface of the operating lever 230. The cap 226 includes a corresponding receiving wall 226a. The side wall 231 of the operating lever 230 can fit over the receiving wall 226a of the cap 226. The first clip portion 231a can slidably engage an inner rim 226c of the receiving wall 226a to secure the operating lever 230 to the cap 226 while allowing relative rotation about the valve stem 228 and preventing relative radial displacement.

[0073] The central shaft 244 has a chamfered edge 244a to define a substantially square cross-section. The central channel 230d of the operating lever includes a corresponding substantially square cross-section opening for receiving the central shaft 244. The chamfered edge of the central shaft 244 can rotatably engage with the central channel 230d to provide a rotatable coupling between the operating lever 230 and the valve core 227. The operating lever 230 also has a lever cap 252 to provide a cover for and / or an end stop for the internal central channel 230d.

[0074] The valves 20, 120, 220 described above may be configured to function as patient breathing circuit connectors and may be configured specifically for use with standard patient assisted breathing equipment. This may include providing standard fittings on each of the first, second and third ports 21 / 121 / 221, 22 / 122 / 222, 23 / 123 / 223. For example, the first port 21, 121, 221 may be configured for connection to a patient airway / breathing tube such as an endotracheal tube 2 or a tracheotomy tube, or via a suction device 3 connected thereto. In this regard, the first port 21, 121, 221 may preferably comprise an inner coaxial conical connector having a male connector with a conical 22 mm outer diameter connector face with a 1:40 taper and a (female) conical connector with a 15 mm inner diameter with a 1:40 taper.

[0075] The second port 22, 122, 222 may be configured for connection to a ventilator 4 via a breathing circuit tubing and may be left open to air when not in use. The second port 22, 122, 222 may comprise a female connector having a conical 22 mm inner diameter connector face with a 1:40 taper. The third port 23, 123, 223 may be configured for connection to a second breathing circuit 6 and may also be left open to air when not in use. The third port 23, 123, 223 may comprise a female connector having a conical 22 mm inner diameter connector face with a 1:40 taper. In this regard, the valve may be specifically configured to comply with relevant national and / or international standards such as ISO5356-1:2004 or ISO5356-1:2015 which specify dimensional and gauging requirements for cones and sockets intended to connect anaesthesia and respiratory equipment, e.g. in breathing systems, anesthetic gas scavenging systems and vaporizers.

[0076] The operating lever 30, 130, 230 allows switching from one breathing circuit 4 to another breathing circuit 6 while maintaining a closed circuit, thus preventing the release of potentially infected aerosols and minimizing the loss of positive end expiratory pressure (PEEP) from the circuit. The valve may preferably be formed as a T-shaped device with ports at relative angles of 90 / 180 degrees, although other angular arrangements of the ports may be envisaged.

[0077] The valve 20, 120, 220 may be formed from a variety of materials. In some instances, one or more components of the valve 20, 120, 220 may be formed from the same material. The valve is preferably made primarily from plastics that are strong and lightweight, such as injection molded parts, and is preferably a disposable device used for a limited period of time, such as up to a few days, with a single patient. Exemplary materials may include polymers such as polyethylene, polysulfone, polyacetal, and polystyrene butadiene.

[0078] The valve preferably transitions from one bistable state to the other bistable state in a period that is very short compared with the period of normal pressure changes in the patient's airway, e.g., substantially less than 1 second, preferably substantially less than 0.2 seconds.

[0079] The valve configuration as described herein provides a fast-acting transition with a definitive, pronounced snap action that provides strong tactile and audible feedback as the valve transitions between its bi-stable states. This is particularly useful in clinical environments to ensure ease of use in potentially noisy and chaotic environments. As an additional safety feature, the directional indicator 30a also provides clear visual feedback regarding the state of the valve and is integrally formed with the operating lever that is rotatably coupled to the valve core 27, so that no ambiguous intermediate indications can be given.

[0080] In the embodiments shown herein, a three-port valve configuration is shown illustrating a bistable valve mechanism in which a first port can be connected to either one of a second and a third port by a fast-transition valve mechanism. It will be understood that further ports may be added and the actuator mechanism supplemented by a third position to provide, for example, a tristable valve mechanism. Such a tristable valve may have a position in which the first port can be connected to either one of the second, third or fourth ports, or there may be a third stable position corresponding to a fully isolated position in which the first, second and third ports are all isolated from each other. In this regard, the expression "bistable valve" is intended to encompass a valve having at least a first and a second stable configuration, where intermediate stable positions between the first and second stable configurations are prevented, but without necessarily excluding the possibility of having further stable configurations while still meeting the given bistable requirements.

[0081] Although the valve embodiments described in relation to the drawings are based on a bistable valve mechanism and actuator mechanism that rotates about an axis, it will be appreciated that the bistable mechanism can be realized in other ways, such as using a valve mechanism that deploys linear motion. For example, the valve may be configured as a Y-valve, with one leg of the Y corresponding to a first port and two branches of the Y corresponding to a second and third port. A linear sliding bistable mechanism may be used to transition the valve from a first configuration, where the first port is in fluid communication with the second port, to a second configuration, where the first port is in fluid communication with the third port.

[0082] For the purposes of providing a low-cost disposable valve, the valves herein are preferably manually operated valves and constructed from low-cost components, although other electrically actuated versions may be envisioned.

[0083] A valve as described above may be deployed to more safely switch a patient connected to a first ventilator using a respiratory support tube to a second ventilator while reducing the risk of the problems identified above. The patient's respiratory tube is coupled to a first port of the valve, the first ventilator is coupled to a second port, and the breathing equipment is operated with the valve in a first stable configuration. While the valve is in the first stable configuration, the second ventilator may be coupled to a third port. The valve may then be switched to a second stable configuration. After transition of the valve to the second stable configuration, the first ventilator may be disconnected from the second port, which is isolated from the patient's active breathing circuit.

[0084] Other embodiments are intended to be within the scope of the following claims.

Claims

1. A respiratory assistance connector valve, comprising: a valve body defining first, second, and third ports; a valve core defining a chamber with ports, wherein the chamber with ports: provides fluid communication between the first port and the second port and separates the third port from the first and second ports in a first stable configuration; is rotatable about a valve axis between a first stable configuration and a second stable configuration, wherein the chamber with ports provides fluid communication between the first port and the third port and separates the second port from the first and third ports; a valve core configured to engage an inner surface of the valve body such that an outer surface of the valve core defines a detent that resists rotation of the valve core between the first stable configuration and the second stable configuration; an actuator configured to overcome the detent to rotate the valve core between the first stable configuration and the second stable configuration.

2. The valve according to claim 1, further comprising a biasing element configured to exert a biasing force along the valve axis to press the outer surface of the valve core and the inner surface of the valve body together.

3. The actuator is configured to overcome the detent and the biasing force such that the valve core rotates about the valve axis between the first stable configuration and the second stable configuration and is displaced along the valve axis away from the inner surface of the valve body. The valve according to claim 1 or claim 2.

4. The valve core comprises a tapered portion defining the chamber with ports, and a second end of the tapered portion is narrower than a first end of the tapered portion. The valve body comprises a tapered portion for receiving the tapered portion of the valve core. The valve according to claim 3.

5. The valve according to claim 1 or claim 2, wherein the valve core comprises one or more seal portions configured to provide a seal between the valve core and the first, second, and third ports on an outer surface of the valve core.

6. The valve according to claim 1 or claim 2, wherein the outer surface of the valve core and the inner surface of the valve body each comprise one or more corresponding detent functional portions configured to engage each other to define the detent.

7. The valve according to claim 6, wherein the outer surface of the valve core and the inner surface of the valve body each comprise undulating surfaces. ​ ​

8. The valve according to claim 7, wherein each undulating surface has a repeating substantially sinusoidal or triangular profile extending around the valve shaft.

9. The valve according to claim 8, wherein at least one of the undulating surfaces is formed as a plurality of concentric rings around the valve shaft.

10. The valve according to claim 1 or claim 2, wherein the outer surface of the valve core and the inner surface of the valve body each have 90-degree rotational symmetry around the valve shaft.

11. The check valve includes a first rotation range and a second rotation range between the first stable configuration and the second stable configuration, the check valve biases the valve core toward the first stable configuration when the valve core is within the first rotation range, the check valve biases the valve core toward the second stable configuration when the valve core is within the second rotation range, The valve according to claim 1 or claim 2.

12. The valve according to claim 1, wherein the actuator is rotatable about the valve shaft and includes a lever coupled to the valve core.

13. The valve according to claim 12, wherein the valve body further includes a cap surrounding a first end of the valve body, the cap including first and second stops for blocking rotation of the lever and the valve core beyond their respective first and second stable configurations.

14. The valve according to claim 12 or claim 13, wherein the valve core is displaceable along the valve shaft relative to the valve body and the lever.

15. The valve according to claim 1 or claim 2, wherein the first port is configured for connection to a patient airway maintenance device, and the second and third ports are each configured for connection to a ventilator breathing circuit or a respiratory assist device.

16. The valve according to claim 15, wherein the first port has a connector face with a tapered outer diameter of 22 mm, and the second and third ports each have a connector face with a tapered inner diameter of 22 mm.

17. The valve according to claim 1 or claim 2, further including a ventilation device connectable to at least one of the second and third ports.

18. The valve according to claim 1 or claim 2, further including an endotracheal tube connectable to the first port.

19. A method of configuring a respiratory assist device for a patient, To provide a valve, the valve comprising: a valve body defining first, second, and third ports; a valve core defining a chamber with ports, the chamber with ports being rotatable about a valve axis between a first stable configuration in which the chamber with ports provides fluid communication between the first port and the second port and separates the third port, and a second stable configuration in which the chamber with ports provides fluid communication between the first port and the third port and separates the second port, the outer surface of the valve core being configured to engage the inner surface of the valve body so as to define a detent that resists rotation of the valve core between the first stable configuration and the second stable configuration; and an actuator configured to overcome the detent so as to rotate the valve core between the first stable configuration and the second stable configuration. Coupling a patient breathing tube to the first port. Coupling a first ventilation device to the second port. While the valve is in the first stable configuration, coupling a second ventilation device to the third port. Switching the valve to the second stable configuration. Disconnecting the first ventilation device from the second port. A method comprising the above.

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