Patent Description:
Respiratory disorders deal with the inability of a sufferer to effect a sufficient exchange of gases with the environment, leading to an imbalance of gases in the sufferer. These disorders can arise as a pathological consequence of an obstruction of the airway, insufficiency of the lungs in generating negative pressure, an irregularity in the nervous function of the brain stem, or some other disorder. Treatment of such disorders is diverse and depends on the particular respiratory disorder being targeted. In the first instance, a constriction of the airway, otherwise known as an obstructive apnea or a hypopnea (collectively referred to as obstructive sleep apnea or OSA), can occur when the muscles that normally keep the airway open in a patient relax during slumber to the extent that the airway is constrained or completely closed off, a phenomenon often manifesting itself in the form of snoring. When this occurs for a significant period of time, the patient's brain typically recognizes the threat of hypoxia and partially wakes the patient in order to open the airway so that normal breathing may resume. The patient may be unaware of these occurrences, which may occur as many as several hundred times per session of sleep. This partial awakening may significantly reduce the quality of the patient's sleep, over time potentially leading to a variety of symptoms, including chronic fatigue, elevated heart rate, elevated blood pressure, weight gain, headaches, irritability, depression, and anxiety.

Obstructive sleep apnea is commonly treated with the application of continuous positive airway pressure (CPAP) therapy. Continuous positive airway pressure therapy involves delivering a flow of gas to a patient at a therapeutic pressure above atmospheric pressure that will reduce the frequency and/or duration of apneas and/or hypopneas. This therapy is typically delivered by using a continuous positive airway pressure device (CPAP device) to propel a pressurized stream of air through a conduit to a patient through an interface or mask located on the face of the patient. The stream of air may be heated to near-body temperature. In some configurations, the stream of air may be humidified. In some such configurations, the stream of air may be humidified by forcing the stream of air to travel through a humidification chamber containing water and a heater for heating the water. In such configurations, the heater encourages the evaporation of the water, which in turn partially or fully saturates the stream of air with moisture. This moisture may help to ameliorate discomfort and/or mucosal tissue damage that may arise from the use of unhumidified CPAP therapy.

During exhalation, the patient's exhaled gases typically flow out of bias flow holes located on the interface, on the connection between the interface and the conduit, or elsewhere in the CPAP circuit (where 'circuit' here is defined as the passageway extending from the inlet of the blower to the interface outlet on or within the interface). Such holes are typically made relatively small to reduce noise, and in use the exhaled gases are pushed through the ports or holes by the gases incoming at therapeutic pressure at rates sufficient to keep CO2 rebreathing at acceptable levels. However, under relatively low pressure conditions, for example, when the patient is not receiving therapy, gases exhaled by the patient may not be able escape from such holes at such rates, and additionally a larger volume of exhaled gases may become entrained in the CPAP circuit on the way out to the flow generator/blower inlet. The combination of these two problems may elevate CO2 rebreathing by the patient to unacceptable or undesirable levels.

In the present disclosure, valves are provided that can be placed in the CPAP circuit that comprises ports open to the environment, where the valve has some means of closing the ports under relatively high pressure conditions (i.e., therapeutic CPAP conditions) and some means of opening the ports under relatively low pressure conditions. In some applications, such valves may be called anti-asphyxia valves (AA valves). In some preferred configurations, such valves are placed close to the patient, e.g. in, at, or close to the interface.

In some configurations, such a valve comprises one or more relatively large ports open to the environment and a flap cantilevered to an internal wall of the valve at one end, where the flap is biased towards a neutral position. Under relatively high pressure conditions, the flap flexes in the direction of the flow and over the ports, and under relatively low pressure conditions, the valve remains in a neutral position (or may flex away from the patient due to exhaled gases flow). In this way, under low pressure conditions, exhaled gases may escape through the ports and the risk of unacceptable CO2 rebreathing may drop to acceptable levels, while under high pressure conditions a low level of leak is maintained and exhaled gases can escape through the bias flow holes.

There are certain disadvantages to such flap-type valves. In these valves, during the transition from a relatively low pressure to a relatively high pressure, the flap quickly 'slaps' or moves over the valve ports in such a way that creates a pressure 'spike' or quick change in pressure in the CPAP circuit, and this 'spike' creates audible noise. Additionally, in such a valve, the flap and the ports are disposed adjacent to each other along the length of the valve, which can make the valve relatively long. In use, a relatively long valve attached to, for example, an interface, may press against a patient's mattress or pillow and displace the mask away from the face, which may disrupt the sealing of the mask. Finally, the traditional port(s) on such a valve is/are relatively large, and exhaled flow through the port(s) may generate a relatively high level of noise due to port size. Accordingly, it is an object of the invention to present a solution or ameliorate at least one or more of the above problems, or at least provide the public with a useful choice.

The present disclosure also describes valves that can be used as constant flow valves, which are valves that can be used to maintain a constant gas flow rate through a gas conduit under varying pressure conditions. The constant flow valve can progressively close the ports as the flow rate decreases, such that the valve allows relatively more gases to escape to the environment at a higher flow rate and relatively less gases to escape at a lower flow rate. In this way, the flow rate of the gases reaching the mask can be maintained at a generally constant flow rate.

Thus, in accordance with at least one of the embodiments disclosed herein, a valve can comprise a body with an interior surface defining a passageway. One or more ports can extend through the body to provide fluid communication between the passageway and the environment. At least one internal member can be attached to the body at two or more discontinuous attachment positions on the internal member, the internal member having a closed configuration that occludes the one or more ports when a gas pressure in the valve is above a threshold pressure and an open configuration that allows gas to pass from the passageway to the environment when the gas pressure in the valve is at or below a threshold pressure.

In some configurations, the interior surface can be curved.

In some configurations, the at least one internal member can move in a direction that is substantially perpendicular to the direction of gases flow through the valve. The at least one internal member can be configured to progressively roll over the interior surface of the body. The at least one internal member can transition between the open configuration and the closed configuration at a distinct threshold pressure.

The at least one internal member can transition between the open configuration and the closed configuration during a range of pressures. In some configurations, the range of pressures is at least approximately <NUM> H2O and/or less than or equal to approximately <NUM> H2O. In some configurations, the range of pressures is at least approximately <NUM> H2O and/or less than or equal to approximately <NUM> H2O.

The one or more ports can be located at generally the same position along the length of the valve as the at least one internal member.

In some configurations, the body can be a round or oval tube and the at least one internal member can extend around at least part of an inner circumference of the body in the closed configuration.

The one or more ports can be disposed around part of the circumference of the body. In some configurations, the one or more ports can be disposed around the entire circumference of the body. The one or more ports can be circular holes having a diameter of approximately <NUM>. In some configurations, the one or more ports have a combined venting area of at least approximately <NUM><NUM> and/or less than or equal to approximately <NUM><NUM>. In some configurations, the one or more ports have a combined venting area of approximately <NUM> mm2.

In some configurations, the threshold pressure can be approximately <NUM> H2O.

The length of the at least one internal member between attachment positions can be approximately the same as the length of the interior surface of the body between the attachment positions. In some configurations, the at least one internal member is a continuous member configured to extend around the interior surface of the body in the closed configuration.

The valve can be configured to be placed at an inlet of a patient interface. In some configurations, the valve can be configured to be placed in-line between a patient interface and a blower.

The at least one internal member can be attached to the body by posts that extend through the body. In some configurations, the at least one internal member can be attached to the body by an adhesive. In some configurations, the at least one internal member is attached by overmoulding onto the body.

In some configurations, the valve can be an anti-asphyxia valve. In other configurations, the valve can be a constant flow valve. The at least one internal member can transition between the open configuration and the closed configuration during pressures ranging from at least approximately <NUM> H2O and/or less than or equal to approximately <NUM> H2O.

In accordance with at least one of the embodiments disclosed herein, a valve can comprise a body with an interior surface defining a passageway, the body configured to be positioned in-line with a flow of respiratory gases. One or more ports can extend through the body to provide fluid communication between the passageway and the environment, the one or more ports disposed around at least part of a circumference of the body. At least one internal member can be attached to the body at two or more discontinuous attachment positions on the internal member, the attachment positions being generally at the same location along the length of the valve as the one or more ports. The at least one internal member can be in an open configuration that allows gas to pass from the passageway to the environment when the gas pressure in the valve is at or below a threshold pressure, the at least one internal member being biased radially inward away from the interior surface. Also, the at least one internal member can be in a closed configuration that occludes the one or more ports when a gas pressure in the valve is above a threshold pressure, the at least one internal member moving radially outward toward the interior surface to occlude the one or more ports.

In some configurations, the interior surface can be curved. In some configurations, the body can be round.

In some configurations, the one or more ports can be disposed around the entire circumference of the body. The one or more ports can be circular holes having a diameter of approximately <NUM>. In some configurations, the one or more ports have a combined venting area of at least approximately <NUM><NUM> and/or less than or equal to approximately <NUM><NUM>. In some configurations, the one or more ports have a combined venting area of approximately <NUM> mm2.

In some configurations, the valve can be an anti-asphyxia valve. In other configurations, the valve can be a constant flow valve. The at least one internal member can transition between the open configuration and the closed configuration during pressures ranging from at least approximately <NUM> H2O and/or less than or equal to approximately <NUM> H2O. <CIT> describes a valve for a breathing apparatus having a flap valve.

Specific embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description herein having reference to the figures that follow, of which:.

In the present disclosure, valves are provided that can be placed in-line in the CPAP circuit with ports that are open to the environment, where the valve can close the ports under relatively high pressure conditions and open the ports under relatively low pressure conditions. In some configurations, these types of valves are known as anti-asphyxia vales (AA valves). In some configurations, the valves are placed close to the patient, e.g. in, at, or close to the interface.

In some configurations, the valve comprises one or more relatively large ports open to the environment and a flap cantilevered at one end to an internal wall of the valve, where the flap is biased towards a neutral position. Under relatively high pressure conditions, the flap can flex in the direction of the gases flow and occlude the ports. Under relatively low pressure conditions, the valve can remain in a neutral position (or may flex away from the patient due to exhaled gases flow). Under low pressure conditions, exhaled gases can escape through the ports and the risk of unacceptable CO2 rebreathing may be mitigated to acceptable levels, while under high pressure conditions the venting of exhaled gases is maintained through the bias flow holes.

The present disclosure also describes valves that can be used as constant flow valves, which are valves that can be used to maintain a constant gas flow rate through a gas conduit under varying pressure conditions. For example, as described in further detail below, the constant flow valve can progressively close the ports as the flow rate decreases, such that the valve allows relatively more gases to escape to the environment at a higher flow rate and relatively less gases to escape at a lower flow rate. In this way, the flow rate of the gases reaching the mask can be maintained at a generally constant flow rate.

Some non-limiting configurations of valves <NUM> are illustrated in <FIG>. <FIG> illustrates a valve <NUM> attached to the elbow connector <NUM> of a full face mask <NUM>. However, in some embodiments, the valve <NUM> can be used with any type of patient interface, such as pillow masks, oral masks, oral-nasal masks, nasal masks, nasal cannulae, etc. In the illustrated configuration, the valve <NUM> is disposed in-line with the gases conduit <NUM>, such that the valve <NUM> has a first end that is in fluid communication with the mask <NUM> and a second end that is in fluid communication with the gases conduit <NUM>. The valve can be placed anywhere in the gas circuit between the blower inlet and the interface inlet. However, the valve <NUM> is preferably attached at or near the inlet of a patient interface.

Positioning the valve closer to the interface inlet beneficially reduces the amount of dead space where CO<NUM> gases can accumulate and beneficially reduces the rebreathing of exhaled gases by the patient. For example, if the valve is positioned near the blower, then CO2 gases would be able to accumulate in at least the mask, elbow connector and the conduit before it can exit to the environment through the valve. The amount of CO2 rebreathing may be at unacceptable levels in this situation. By positioning the valve adjacent the elbow connector, CO2 gases would only accumulate in the mask and elbow connector, reducing the amount of CO2 rebreathing to acceptable levels.

With reference to <FIG>, the valve <NUM> can have a tubular body <NUM> with an interior surface <NUM> and an exterior surface <NUM>. The interior surface <NUM> surrounds a passageway <NUM> through which fluids can flow. In the illustrated configuration, the valve <NUM> has a cylindrical shape with a generally circular cross-section. The valve can have any of a plurality of different shapes, such as a tube with an oval, square, rectangular or polygonal cross-section. The internal diameter of the valve can be any size that is suitable for use in a respiratory circuit, preferably without restricting the gas flow. For example, the internal diameter of the body <NUM> can be approximately <NUM>. In some configurations, the internal diameter of the body can range from at least approximately <NUM> and/or less than or equal to approximately <NUM>.

In some configurations, the body of the valve may not be straight and instead may have a bend, such as a <NUM> degree or <NUM> degree bend. The bend in the body of the valve can advantageously help route the circuit to minimize interference with other objects, such as the patient's mattress or pillow, which can lead to displacement of the mask away from the face and disruption of the mask seal. In some configurations, the valve can be integrated or built into the elbow connector. This can position the valve closer to the interface inlet, beneficially reducing the amount of dead space, as discussed above.

The valve <NUM> has an internal member <NUM> that can be coupled to the interior wall <NUM> of the valve <NUM>, as illustrated in <FIG>. The internal member can be configured to occlude the ports of the valve when the gas flow pressure is above a threshold pressure and not occlude the ports when the gas flow pressure is below the threshold pressure, as described in further detail below. In the illustrated configuration, the internal member <NUM> is an elongate ribbon in the passageway <NUM> that is apposed to the ports of the valve <NUM>. The illustrated internal member <NUM> is a continuous ribbon that is attached to the body <NUM> by three posts <NUM> that extend through the body <NUM> of the valve <NUM>.

With continued reference to <FIG>, the valve <NUM> comprises one or more ports <NUM>. The ports <NUM> can be through holes in the body <NUM> of the valve <NUM> that extend from the interior surface <NUM> to the exterior surface <NUM> such that the passageway <NUM> is in fluid communication with the environment through the ports <NUM>. In the illustrated configuration, the valve <NUM> has a plurality of relatively small ports <NUM> that are arranged in two rows extending around the body <NUM>. The ports <NUM> are located at approximately the same position along the length of the valve <NUM> as the internal member <NUM>, such that the internal member <NUM> can overlap and occlude the ports <NUM> when the gas flow pressure is above a threshold pressure.

When the gas flow pressure is below a certain threshold, the internal member <NUM> is in its neutral configuration and curves away from the interior surface <NUM>, forming folds <NUM> in the internal member <NUM>. The folds <NUM> are approximately the same length as the sealing surface <NUM>, which is the area on the interior wall <NUM> between the posts <NUM> where the ports <NUM> are disposed. When the gas flow pressure is above a certain threshold, the folds <NUM> are urged to curve toward the interior surface <NUM> until the folds <NUM> of the internal member <NUM> abut the sealing surface <NUM> and occlude the ports <NUM>.

In use, under relatively low pressure conditions, exhaled gases can escape through ports <NUM> when the internal member <NUM> is in a neutral position as shown in <FIG>. In the neutral position, the internal member <NUM> does not occlude the ports <NUM> and exhaled gases can flow freely through the ports <NUM> to the environment. When the system transitions to relatively high pressure conditions (e.g. the CPAP blower is turned on) and the pressure of the gas flow meets or exceeds a threshold pressure, the leading contact edges <NUM> of the folds <NUM> of the internal member <NUM> can roll to abut the sealing surface <NUM> of the valve <NUM>, thereby occluding the ports <NUM> as shown in <FIG>. In some configurations, the pressure of the gases moving through the valve <NUM> can apply forces on the folds <NUM> of the internal member <NUM> to move the folds <NUM> against the interior surface <NUM> of the valve <NUM> in a direction substantially perpendicular to the direction of gas flow. In these configurations, the folds <NUM> are moved substantially by the gas pressure within the valve <NUM> and not by the forces from the gas velocity, and the valve <NUM> can be described as a pressure-dependent valve rather than a flow-dependent valve.

The internal member is preferably configured to be flexible. The internal member can be made of a pliable material that can bend and flex easily, such as for example silicone. The internal member can also have a shape that is configured for flexibility, such as for example a thin, flat shape. The thickness of an internal member for an AA valve can be at least approximately <NUM> millimeter and/or less than or equal to approximately <NUM> millimeter. This internal member may have an operating threshold pressure of approximately <NUM>-<NUM> H2O. In some configurations, the thickness of the internal member can be at least approximately <NUM> millimeter and/or less than or equal to approximately <NUM> millimeter.

The valves described herein advantageously operate without significantly restricting the flow path. As mentioned above, the internal member <NUM> moves in a direction substantially perpendicular to the direction of gas flow and only a thin edge, or cross-section, of the internal member <NUM> is in the path of the gas flow, as can be seen in <FIG>. In contrast, other valve designs, such as the flap type valve, can restrict the flow path. For example, a flap valve in certain positions may almost completely block the flow path and the air flow is forced to go around the flap valve or push the flap out of the way. This can affect the flow measurements of the respiratory device (e.g., CPAP). The valves disclosed herein advantageously are not flow dependent, rather pressure dependent, and can even operate when there is no change in flow velocity or even zero flow velocity.

In some configurations, the rolling motion of the internal member <NUM> and the progressive occlusion of the ports <NUM> can advantageously help to reduce valve noises, which are traditionally caused by the slapping motion of a traditional flap valve. When the internal member <NUM> is exposed to gas flow that meets or exceeds the threshold pressure, the folds <NUM> of the internal member <NUM> can gradually roll over the sealing surface <NUM> until the sealing surface <NUM> and the ports <NUM> are substantially covered by the folds <NUM> and the valve <NUM> is substantially in a closed configuration, as shown in <FIG>. <FIG> taken together may represent a continuum of internal member <NUM> positions from substantially open to substantially closed. In some configurations, the pressure at which the valve <NUM> may close from an open state, or open from a closed state, is approximately <NUM> H2O. In some configurations, the pressure at which the valve transitions from the open and closed states can be at least approximately <NUM> H2O and/or less than or equal to approximately <NUM> H2O. In some configurations, the pressure at which the valve transitions from the open and closed states can be at least approximately <NUM> H2O and/or less than or equal to approximately <NUM> H2O.

In some configurations, the internal member <NUM> can progressively abut the sealing surface <NUM> through a range of operating pressures. For example, the internal member <NUM> can be in a fully open configuration, as illustrated in <FIG>, until the gas pressure increases to reach approximately a lower threshold pressure, such as <NUM> H2O. The folds <NUM> can gradually roll to abut an increasing area of the sealing surface <NUM> as the pressure continues to increase. An increasing number of ports <NUM> are also progressively occluded as the folds <NUM> gradually roll against the sealing surface <NUM>. Thus, as the gas pressure increases, the total area of the ports <NUM> through which exhaled gases can escape decreases. When the gas pressure reaches approximately an upper threshold pressure, such as <NUM> H2O, the folds <NUM> can be substantially abutted against the sealing surface <NUM> in a fully closed configuration.

Similarly, as the gas pressure decreases, the internal member <NUM> can start to gradually roll away from the sealing surface when the gas pressure reaches approximately an upper threshold pressure. The internal member <NUM> can progressively roll away from the sealing surface <NUM> as the gas pressure continues to decrease. An increasing number of ports <NUM> are also progressively opened as the folds <NUM> gradually roll away from the sealing surface <NUM>, and the total area of the ports <NUM> increases. When the gas pressure reaches approximately a lower threshold pressure, the folds <NUM> are substantially separated from the sealing surface, as illustrated in <FIG>, and the internal member <NUM> is in a fully open configuration. In some configurations, the lower threshold pressure can be at least approximately <NUM> H2O and/or less than or equal to approximately <NUM> H2O. In some configurations, the upper threshold pressure can be at least approximately <NUM> H2O and/or less than or equal to approximately <NUM> H2O.

The range of operating pressures of the internal member <NUM> while transitioning from an open to a closed configuration can be the same as the range of pressures for transitioning from a closed to an open configuration. For example, the internal member <NUM> can start to roll onto the sealing surface <NUM> into a closed configuration at approximately <NUM> H2O and be in a fully closed configuration at approximately <NUM> H2O. The same internal member <NUM> can start to roll away from the sealing surface <NUM> into an open configuration at approximately <NUM> H2O and be in a fully open configuration at approximately <NUM> H2O.

In some configurations, the range of operating pressures can be different depending on whether the internal member <NUM> is transitioning from an open to closed configuration, or from a closed to open configuration. For example, the internal member <NUM> can start to roll onto the sealing surface <NUM> into a closed configuration at approximately <NUM> H2O and be in a fully closed configuration at approximately <NUM> H2O. The same internal member <NUM> can start to roll away from the sealing surface <NUM> into an open configuration at approximately <NUM> H2O and be in a fully open configuration at approximately <NUM> H20.

In some configurations, the internal member <NUM> can transition from the open configuration to the closed configuration at a particular threshold pressure, instead of gradually transitioning throughout a range of operating pressures. The valve can act as a "digital valve" where the internal member is in an open configuration when the gas pressure is at or below a threshold value, and in a closed configuration when the gas pressure is above the threshold value. For example, the internal member can be in the fully open configuration until the gas pressure reaches the threshold value, such as <NUM> H2O. When the threshold value is reached, the internal member can transition to the fully closed configuration.

In some configurations, the valve can be a constant flow valve that helps maintain a generally constant gas flow rate through a gas conduit under varying pressure conditions. As described above, the internal member can progressively roll over the ports through a range of pressures. In constant flow valves, the internal member can progressively occlude the ports as the flow rate decreases, which causes the pressure to increase. The valve allows relatively more gases to escape to the environment through the ports at a higher flow rate and relatively less gases to escape at a lower flow rate such that a generally constant flow rate, or at least a small range of flow rates, is delivered to the mask. Preferably, the internal member is thicker compared to the internal member used for some other valves, such as the AA valve. For example, the thickness of the internal member for a constant flow valve can be approximately <NUM> millimeter. In some configurations, the thickness of the internal member for a constant flow valve can range from at least approximately <NUM> millimeter and/or less than or equal to approximately <NUM> millimeter. In some configurations, the internal member can start to roll onto the sealing surface into a closed configuration at approximately <NUM> H2O and be in a fully closed configuration at approximately <NUM> H2O.

In a constant flow valve the internal member can progressively abut the sealing surface through a range of operating flow rates, which inversely corresponds to a range of operating pressures. For example, the internal member can be in a fully open configuration at a relatively high gas flow rate until the gas flow rate decreases to reach approximately an upper threshold flow rate. The upper threshold flow rate can have a corresponding gas pressure, such <NUM> H2O. The folds of the internal member can gradually roll to abut an increasing area of the sealing surface as the flow rate decreases, and consequently causes the pressure to increase. An increasing number of ports are also progressively occluded as the folds gradually roll against the sealing surface. Thus, as the flow rate decreases and the gas pressure increases, the total area of the ports through which gases flowing through the valve can escape to environment decreases, allowing more gases to reach the mask. When the flow rate reaches approximately a lower threshold flow rate, the folds can be substantially abutted against the sealing surface in a fully closed configuration such that substantially all the gases flowing through the constant flow rate valve are delivered to the mask. The lower threshold flow rate can have a corresponding gas pressure, such as <NUM> H2O.

Similarly, as the flow rate increases and the gas pressure decreases, the internal member can start to gradually roll away from the sealing surface at approximately a lower threshold flow rate. The lower threshold flow rate can have a corresponding gas pressure, such <NUM> H2O. The internal member can progressively roll away from the sealing surface as flow rate increases and consequently the gas pressure decreases. An increasing number of ports are also progressively opened as the folds gradually roll away from the sealing surface and the total area of the ports through which gases can escape to the environment increases. When the flow rate reaches approximately an upper threshold flow rate, the folds are substantially separated from the sealing surface and the internal member is in a fully open configuration, such that gases are allowed to escape through all the ports of the valve. The upper threshold flow rate can have a corresponding gas pressure, such as <NUM> H2O.

The illustrated internal member <NUM> has generally an elongate, rectangular shape. In some configurations, the internal member <NUM> can have other shapes, such as for example round shapes or zig-zag shapes. The internal member can be made of a pliable material that can bend and flex easily from the open configuration to the closed configuration. For example, the internal member can at least partially be made of silicone, rubber, flexible plastics, paper, etc..

In some configurations, as illustrated in <FIG>, the ports <NUM> are located at approximately the same position along the length of the valve <NUM> as the internal member <NUM>, such that the internal member <NUM> can overlap and occlude the ports <NUM> when the gas flow pressure is above a threshold pressure. These configurations advantageously provide for a valve <NUM> that is compact and shorter in length than traditional valves, where the ports and valve flaps are sequentially next to each other along the length of the valve.

In some configurations, as illustrated in <FIG>, the internal member <NUM> is attached to the valve <NUM> by posts <NUM> that extend through the body <NUM> of the valve <NUM>. The posts <NUM> can be made of the same material as the internal member <NUM>. In some configurations, the posts <NUM> and internal member <NUM> can be made from different materials. For example, the posts <NUM> may be made of a plastic material while the internal member <NUM> is made of rubber. The two components can be welded, adhered or otherwise coupled together. In some configurations, during assembly the posts <NUM> can be forced through orifices that extend through the valve body <NUM>. The orifices can be similarly-sized to the posts for a close fit between the orifices and posts. The posts <NUM> can have flanges <NUM> that are wider than the orifices to hold the posts in place and to help prevent the posts from being pulled back through the orifices, as illustrated in <FIG>.

The internal member <NUM> can be coupled to the body <NUM> by any of a plurality of different types of functional couplers. For example, the internal member <NUM> can be glued to the interior surface <NUM> of the valve <NUM> using an adhesive, overmoulded onto the body <NUM> of the valve <NUM>, or affixed to the interior surface <NUM> of the valve <NUM> via ultrasonic welding. Any suitable attachment method can be used and preferably the internal member <NUM> is pliable enough to cover the ports <NUM>, in use.

In some configurations, the internal member <NUM> can be removable from the valve body <NUM> for easy replacement, cleaning or service. For example, the posts <NUM> can be deformable so that they can be detached from the body <NUM> and preferably re-attachable after cleaning or servicing. A removable internal member can advantageously allow for customization of the valve performance, such as customizing the gas pressure at which the internal member switches from the open to closed configuration.

In some configurations, the internal member <NUM> can be attached to an internal ring <NUM> or other element that may be inserted inside the passageway <NUM> of the valve <NUM>, instead of or in addition to being attached or anchored directly to the body <NUM> of the valve <NUM>, as illustrated in <FIG>. With reference to <FIG> and <FIG>, the internal ring <NUM> can have gaps <NUM> through which gases can flow through to the ports <NUM>. The internal ring <NUM> can be pressed into the body <NUM> of the valve <NUM>, such as through an interference fit, or can be coupled by any retaining feature, such as for example hooks, clips, screw threads, tongue-and-grooves, etc. The internal ring <NUM> can be removable from the body <NUM> of the valve <NUM>, and in some configurations, the internal member <NUM> can be removable from the internal ring <NUM>.

The ports <NUM> are through holes in the body <NUM> of the valve <NUM> that enable fluid communication between the passageway <NUM> and the environment. The ports <NUM> can be any suitable size, shape, and/or configuration. In the illustrated configurations, the ports are small circular holes that are generally perpendicular to the body <NUM>, such that the ports extend normal to the interior and exterior surfaces. In other configurations, the ports can extend at an angle to the body <NUM>. The port directions can allow for directing the flow of gases vented from the valve. In some configurations, the ports can have an oval shape, rectangular shape, or other shape besides circular holes. For example, the ports can comprise an elongate oval shaped hole disposed between the posts. In some configurations, the ports can include a combination of different shaped holes, such as polygonal ports and oval ports. The ports are preferably relatively small holes, which can help reduce noises from the venting gases. In some configurations, the ports are substantially circular holes of approximately <NUM> in diameter. In some configurations, the ports can range from at least approximately <NUM> in diameter and/or less than or equal to approximately <NUM> in diameter.

The total venting area of the ports is configured to allow adequate CO2 flushing while keeping the ports small to reduce venting noises. For example, the total cross-sectional area of all the ports can be approximately <NUM><NUM>. This can be achieved, for example, with approximately <NUM> ports, each having a <NUM> diameter hole. In some configurations, the total cross-sectional area of all the ports can range from at least approximately <NUM><NUM> and/or less than or equal to approximately <NUM><NUM>.

With reference to <FIG> and as described above, the illustrated embodiment comprises a plurality of ports that are arranged in two rows extending around the body <NUM>. In some configurations, the ports may comprise a plurality of holes arranged in a single row or more than two rows extending around the body, or partially around the body. The ports <NUM> are located at approximately the same position along the length of the valve <NUM> as the internal member <NUM>, such that the internal member <NUM> can overlap and occlude the ports <NUM> when the gas flow pressure is above a threshold pressure. In some configurations, the ports may only be disposed around a portion or portions of the body. For example, the ports may be disposed on half of the circumference of the body, as illustrated in <FIG>. In another example, the ports may be disposed on two opposite portions of the body.

In some preferred configurations, the size of the ports <NUM> is selected in such a way that both acceptable CO2 flushing and acceptable noise generation are achieved. In some preferred configuration, the valve ports <NUM> and the internal member <NUM> are coaxial along the length of the valve <NUM>, which may be an efficient use of space.

The length of the folds <NUM> of the internal member <NUM> can be approximately the same length as the corresponding sealing surface <NUM>, such that the internal member <NUM> adequately occludes all the ports <NUM> when the internal member <NUM> is in the closed configuration. In some configurations, the folds <NUM> can be slightly shorter or slightly larger in length than the sealing surface <NUM> and still provide sufficient occlusion of the ports <NUM>. The internal member <NUM> can be made of a pliable material, such as rubber, that can stretch and/or compress to conform to the length of the sealing surface <NUM>. For example, in a valve having an internal diameter of about <NUM>, the length of the internal member extending around the entire interior surface can be approximately <NUM>.

In the embodiments illustrated in <FIG>, the internal member <NUM> is a single continuous member connected integrally with the posts <NUM>. However, in other embodiments, the internal member <NUM> can be several discontinuous internal members, each attached to the body <NUM> at both ends of the internal member, such as illustrated in <FIG> illustrates a cross-sectional view of a valve <NUM> with an internal member <NUM> that comprises a single fold <NUM> and is attached to the interior surface <NUM> at both ends of the internal member <NUM>. The valve <NUM> comprises a set of ports <NUM> on one side of the valve <NUM>. <FIG> illustrates a configuration of a valve <NUM> comprising two internal members <NUM>, each comprising a fold <NUM>. Each internal member <NUM> is attached to the interior surface <NUM> at both ends of the internal members <NUM>.

The internal member <NUM> can have any number of folds <NUM>. For example, the internal member <NUM> can comprise one, two, three or more than three folds <NUM> along the length of the internal member <NUM>. Some non-limiting examples of these configurations are shown in <FIG> illustrates a configuration of a valve <NUM> in which the internal member <NUM> comprises four folds <NUM> and the valve <NUM> comprises four sets of ports <NUM>. <FIG> shows a configuration in which the internal member <NUM> comprises five folds <NUM> and the valve <NUM> comprises five sets of ports <NUM>. As implied in <FIG>, the valve can comprise any number of folds and a corresponding number of sets of ports. However, in some embodiments, the number of folds and the number of sets of port may not be the same.

The valve body can have any of a plurality of different shapes, in addition to the circular or round shapes described above. In some configurations, the valve body can be a tube with a square cross-sectional shape, as illustrated in <FIG>. The valve body can be a tube having an octagonal cross-sectional shape, as illustrated in <FIG>, or a hexagonal cross-sectional shape, as illustrated in <FIG>. In some configurations, the valve body can be a tube with other cross-sectional shapes besides those provided in the examples of <FIG>, such as rectangular, oval, triangular, other polygonal shapes, or any other shape.

<FIG> illustrates a cross-sectional view of a valve <NUM> having a square shaped body. The internal member <NUM> is attached to the body with posts <NUM> located toward the middle of the side walls. The illustrated configuration has four posts <NUM> and one internal member <NUM>. However, as discussed above in other configurations, the valve can have more than one internal member and can be attached at any number of different locations on the body in more or less than four post locations. The illustrated internal member <NUM> has four folds <NUM> that are configured to occlude ports <NUM> that are located toward the corners of the walls. <FIG> illustrates the valve <NUM> in a closed configuration. The folds <NUM> can extend around the corners of the walls to occlude the ports <NUM>.

<FIG> illustrates a cross-sectional view of a valve <NUM> having a square shaped body, similar to <FIG>, but with the posts <NUM> attached at the corners of the body. In the open configuration, the folds <NUM> are biased away from the walls of the body so that the ports <NUM> are open to the environment. In the closed configuration, as illustrated in <FIG>, the folds <NUM> are against the walls of the body to occlude the ports <NUM>. Preferably the internal member <NUM> is compliant so that it can compress to a shorter length in the closed configuration and extend to a longer length in the open configuration.

<FIG> illustrates a cross-sectional view of a valve <NUM> having an octagonal shaped body. The internal member <NUM> is attached to the body with posts <NUM> located at four of the corners of the side walls. The illustrated configuration has four posts <NUM> and one internal member <NUM>. However, as discussed above in other configurations, the valve can have more than one internal member and can be attached at any number of different locations on the body in more or less than four post locations. The illustrated internal member <NUM> has four folds <NUM> that are configured to occlude ports <NUM> that are located toward the corners of the walls. <FIG> illustrates the valve <NUM> in a closed configuration. The folds <NUM> can extend around the corners of the walls to occlude the ports <NUM>.

<FIG> illustrates a cross-sectional view of a valve <NUM> having a hexagonal shaped body. The internal member <NUM> is attached to the body with posts <NUM> located toward the middle of some of the side walls. The illustrated configuration has three posts <NUM> and one internal member <NUM>. However, as discussed above in other configurations, the valve can have more than one internal member and can be attached at any number of different locations on the body in more or less than three post locations. The illustrated internal member <NUM> has three folds <NUM> that are configured to occlude ports <NUM> that are located on the walls of the body. <FIG> illustrates the valve <NUM> in a closed configuration. The folds <NUM> can extend around the corners of the walls to occlude the ports <NUM>. In the illustrated configuration, each fold <NUM> lies against three of the walls, partially over two walls and one entire wall.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to.

The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

Certain features, aspects and advantages of an embodiment of the present invention have been described with reference to a CPAP apparatus, particularly for use in the treatment of obstructive sleep apnea. However, certain features, aspects and advantages of the valve as described above may be advantageously used with other therapeutic or non-therapeutic breathing devices, such as non-invasive ventilators, or for the treatment of other conditions, such as COPD. Certain features, aspects and advantages of the method and apparatus of the present disclosure may be equally applied to other breathing devices for other conditions.

Claim 1:
A valve (<NUM>) configured for use in positive airway pressure therapy, the valve (<NUM>) comprising:
a tubular body (<NUM>) with an interior surface (<NUM>) and an exterior surface (<NUM>), the interior surface (<NUM>) surrounding a passageway (<NUM>) through which fluids can flow;
one or more ports (<NUM>) comprising through holes in the body (<NUM>) that extend from the interior surface (<NUM>) to the exterior surface (<NUM>) such that the passageway (<NUM>) is in fluid communication with the environment through the ports (<NUM>); and
at least one internal member (<NUM>) attached to the body (<NUM>) at two or more discontinuous attachment positions on the internal member (<NUM>),
wherein the at least one internal member (<NUM>) comprises an elongate ribbon that is apposed to the ports of the valve, the internal member (<NUM>) configurable between an open configuration in which the ribbon is configured to curve away from the interior surface (<NUM>) of the body when a gas pressure is at or below a threshold pressure in use; and a closed configuration in which the ribbon is configured to abut the interior surface (<NUM>) to occlude the ports (<NUM>) when a gas pressure is above a threshold pressure in use.