Pressure relief device and components thereof

Abstract

The present invention relates to pressure relief devices and components thereof. A connector has a connector body having an inlet and an outlet defining a gas flow passage therebetween. The connector body has an overlap portion configured to overlap a portion of a second connector when connected. An access passage extends through the overlap portion to the gas flow passage.

Description

[0001] This application is a divisional application of the Chinese Patent Application with the title “Pressure relief device and components thereof” (Application No. 2020100776978) filed on January 31, 2020. TECHNICAL FIELD

[0002] The present disclosure relates to a pressure relief device for a medical system for transferring gas to and / or from a patient, in particular a flow and / or pressure compensated pressure relief device, a septum component and a connector thereof. BACKGROUND

[0003] Respiratory gas supply systems provide gas for delivery to a patient. Respiratory gas supply systems typically include a fluid connection between a gas supply and the patient. This can include an inspiratory tube and a patient interface. Such systems include many different components to ensure that gas is properly delivered to the patient. Many of the components are single-use components that are disposed of after each use, while other components are multi-use components. In some cases, multi-use components are preferred. In some cases, single-use components must be connected to multi-use components. However, if the single-use components are not properly or unexpectedly assembled with the multi-use components, this can cause problems. Furthermore, some components are complex products with different features and functions. The design and / or production of such components cannot be easily changed or altered.

[0004] In pressure relief valves containing a flexible diaphragm, the diaphragm(s) can be susceptible to oscillations during normal use due to resonance of the diaphragm and fluctuations in pressure in the chamber adjacent to the diaphragm. These oscillations cause noise and reduce the stability of the valve, particularly when the diaphragm is lifted from the valve seat. Larger and higher frequency oscillations are associated with lower stability and higher noise levels. Such oscillations can also increase the hysteresis in the valve, i.e. increase the lag time after a blockage in the conduit has been removed before flow is restored. SUMMARY

[0005] It is therefore an object of certain embodiments disclosed herein to provide a connector that will at least to some extent solve the aforementioned problems or will at least provide a useful alternative in the industry.

[0006] In a first aspect, there is provided a connector comprising: a connector body having an inlet and an outlet defining a gas flow passage therebetween; the connector body having an overlap portion configured to overlap with a portion of a second connector when connected; and an access passage extending through the overlap portion to the gas flow passage.

[0007] The access passage can comprise an orifice to be in fluid communication with the gas flow passage to sense pressure in the gas flow passage.

[0008] The airflow passage can be at least partially defined by a wall, and the entry passage can comprise an aperture in the wall of the connector.

[0009] The connector can further comprise a cavity-forming portion configured to form a cavity with the second connector.

[0010] The cavity-forming portion can comprise an arcuate surface.

[0011] The cavity-forming portion can be a recess in a surface of the connector body.

[0012] The cavity-forming portion can be in fluid communication with the airflow passage via the entry passage.

[0013] The cavity-forming portion can have a longitudinal dimension that can be substantially parallel to a direction of airflow in the airflow passage.

[0014] The connector can further comprise a first sealing mechanism configured to form a first seal with a portion of the second connector.

[0015] The first sealing mechanism can comprise one or more of: a face seal, an O-ring, a lip seal, a dust seal, or a sealing surface.

[0016] The overlap portion can comprise the first sealing mechanism.

[0017] The first sealing mechanism can comprise an inner or outer sealing surface for friction / interference fit with the second connector.

[0018] The entry and / or cavity-forming portion can be arranged upstream of the first sealing mechanism.

[0019] The connector can further comprise a second sealing mechanism configured to form a second seal with a portion of the second connector.

[0020] The cavity-forming portion can be between the first sealing mechanism and the second sealing mechanism.

[0021] The entry passage can be positioned between the first sealing mechanism and the second sealing mechanism.

[0022] The second sealing mechanism can comprise one or more of: a face seal, an O-ring, a lip seal, a dust seal, or a sealing surface.

[0023] The overlap portion can comprise the second sealing mechanism.

[0024] The second sealing mechanism can comprise an inner or outer sealing surface for friction / interference fit with the second connector.

[0025] A portion and / or surface of the connector can be tapered.

[0026] The connector can further comprise one or more alignment features.

[0027] The aperture can be arranged substantially parallel or substantially perpendicular to a direction of airflow in the airflow passage.

[0028] The aperture can be arranged radially around the airflow passage.

[0029] The connector can further comprise a stepped portion and the aperture can be arranged on the stepped portion.

[0030] The connector aperture can be in fluid communication with the airflow passage via a further aperture, which can be in fluid communication by a channel.

[0031] The connector can further comprise a flow restriction.

[0032] The flow restriction can be provided at a terminal end of the connector.

[0033] The flow restriction can be arranged in a recess.

[0034] The flow restriction can be provided by a constraint spaced apart from a terminal end of the connector.

[0035] The constraint can be a venturi.

[0036] The entry passage can be provided at, or immediately adjacent and downstream of, the flow restriction.

[0037] The connector body can taper outwardly from the terminal end, tapering from a smaller diameter to a larger diameter.

[0038] The connector can further comprise a stop.

[0039] The stop can be or can comprise a collar.

[0040] A surface of the collar can be configured to form a face seal with a surface of the second connector.

[0041] The connector can further comprise a radial gap adjacent the terminal end of the connector.

[0042] The cavity-forming portion can taper with respect to a direction of airflow.

[0043] The airflow passage can be or can include a pressure line.

[0044] The connector can taper toward a terminal end, tapering from a smaller diameter to a larger diameter.

[0045] The connector can be configured to be coupled to a pressure relief valve.

[0046] The connector can further include an engagement mechanism configured to couple the connector to a pressure relief valve.

[0047] The connector can be integral with a pressure relief valve.

[0048] The pressure relief valve can be a flow and / or pressure compensated pressure relief valve.

[0049] The pressure line can be in fluid communication with a sensing chamber of the pressure relief valve.

[0050] The pressure relief valve can include a sensing member configured to sense a pressure differential between the sensing chamber and a main airflow passage providing airflow to a patient.

[0051] Movement of the sensing member can change the discharge pressure of a valve member.

[0052] The pressure line can be a first pressure line, and the connector further includes a second pressure line that can be upstream of the first pressure line.

[0053] The connector can be configured to be coupled to a circuit component.

[0054] The connector can further include an engagement mechanism configured to engage the connector with the circuit component.

[0055] The first pressure line and the second pressure line can each be coupled to a pressure sensing mechanism.

[0056] In a second aspect, there is provided a connector including: an inlet and an outlet defining an airflow passage therebetween; a flow restriction configured to restrict flow through the airflow passage; and an access passage to the airflow passage, the access passage being arranged downstream of the flow restriction.

[0057] The airflow passage can be at least partially defined by a wall, and the access passage can include an aperture in the wall of the connector.

[0058] The flow restriction can be in a recess at the inlet.

[0059] A portion and / or surface of the connector can be tapered.

[0060] The entry passage can be arranged between the first sealing mechanism and the flow restriction.

[0061] The entry passage can be provided at, or immediately adjacent and downstream of, the flow restriction.

[0062] The first sealing mechanism can comprise one or more of: a face seal, an O-ring, a lip seal, a dust seal, or a sealing surface.

[0063] The surface can comprise an arcuate surface.

[0064] The sealing surface can be sealed via a friction / interference fit with an inner surface of a second connector.

[0065] The connector can be a two-piece connector, a first piece comprising the flow restriction and a second piece comprising the first sealing mechanism.

[0066] The first and second pieces can be separated by a gap.

[0067] The first and second sections can be linked.

[0068] The flow restriction can be upstream of the first sealing mechanism.

[0069] The connector can further comprise a cavity-forming portion configured to form a cavity with a second connector.

[0070] The connector cavity-forming portion can comprise an outer arcuate surface.

[0071] The cavity-forming portion can be in fluid communication with the airflow passage via the entry passage.

[0072] The cavity-forming portion can have a longitudinal dimension which can be substantially parallel to a direction of airflow in the airflow passage.

[0073] The connector can further comprise a second sealing mechanism arranged between the terminal and the entry passage and / or the cavity-forming portion.

[0074] The second sealing mechanism can comprise one or more of: a face seal, an O-ring, a lip seal, a dust seal, or a sealing surface.

[0075] The sealing surface can comprise an arcuate or curved surface.

[0076] The sealing surface can be sealed via a friction / interference fit with an inner surface of a second connector.

[0077] The connector can further comprise a stop.

[0078] The stop can be or can comprise a collar.

[0079] A surface of the collar can be configured to form a face seal with a surface of the second connector.

[0080] The connector can be configured to connect to a second connector having a pressure line that can be in fluid communication with the aperture.

[0081] In a third aspect, there is provided an assembly comprising: a first connector comprising a connector body having an inlet and an outlet defining a first connector airflow passage therebetween and an overlap portion; a second connector comprising a connector body having an inlet and an outlet defining a second connector airflow passage therebetween and an overlap portion; wherein the first connector and the second connector are configured to be assembled such that the overlap portion of the first connector and the overlap portion of the second connector are continuous to form an overlap connection and to provide an assembly airflow passage; and an access passage extending through the overlap connection to the assembly airflow passage.

[0082] The access passage can comprise an aperture to be in fluid communication with the airflow passage to sense a pressure in the airflow passage.

[0083] The airflow passage can be at least partially defined by a wall, and the access passage can comprise an aperture in the wall of the connector.

[0084] The flow restriction can be in a recess at the inlet of the second connector.

[0085] A portion and / or a surface of the connector can be tapered.

[0086] The access passage can be arranged between a first sealing mechanism and the flow restriction.

[0087] The access passage can be provided at, or immediately adjacent and downstream of, the flow restriction.

[0088] The first sealing mechanism can comprise one or more of: a face seal, an O-ring, a lip seal, a dust seal, or a sealing surface.

[0089] The sealing surface can comprise an arcuate surface.

[0090] The sealing surface can be sealed via a friction / interference fit with an inner surface of a second connector.

[0091] The connector can be a two-piece connector, a first piece including the flow restriction and a second piece including the first sealing mechanism.

[0092] The first and second sections can be interfaced.

[0093] The flow restriction can be upstream of the first sealing mechanism.

[0094] The assembly can further include a cavity defined by the first connector and the second connector.

[0095] The cavity can be defined by an outer arcuate surface of the first connector.

[0096] The cavity can be in fluid communication with the airflow passage via the access passage.

[0097] The cavity can have a longitudinal dimension that can be substantially parallel to a direction of airflow in the airflow passage.

[0098] The assembly can further include a second sealing mechanism arranged between the terminal and the access passage and / or the cavity.

[0099] The second sealing mechanism can include one or more of: a face seal, an O-ring, a lip seal, a dust seal, or a sealing surface.

[0100] The sealing surface can include an arcuate or curved surface.

[0101] The sealing surface can be sealed via a friction / interference fit with an inner surface of a second connector.

[0102] The second connector can further include a stop.

[0103] The stop can be or can include a collar.

[0104] A surface of the collar can be configured to form a face seal with a surface of the second connector.

[0105] The first connector can have a pressure line that can be fluidly coupled to the orifice.

[0106] In a fourth aspect, there is provided an assembly comprising a first connector and a second connector, the first and second connectors configured to be assembled together to provide an inlet, an outlet and an assembly airflow passage; the first connector comprising a port; the second connector comprising a flow restriction and an access passage, the flow restriction configured to restrict flow through the airflow passage, the access passage configured to allow the port to be in fluid communication with the assembly airflow passage.

[0107] The airflow passage can be at least partially defined by a wall, and the access passage can comprise an aperture in the wall of the connector.

[0108] The flow restriction can be in a recess at the inlet of the second connector.

[0109] A portion and / or surface of the connector can be tapered.

[0110] The access passage can be arranged between a first sealing mechanism and the flow restriction.

[0111] The access passage can be provided at, or immediately adjacent and downstream of, the flow restriction.

[0112] The first sealing mechanism can comprise one or more of: a face seal, an O-ring, a lip seal, a dust seal or a sealing surface.

[0113] The sealing surface can comprise an arcuate surface.

[0114] The sealing surface can seal via a friction / interference fit with an inner surface of the second connector.

[0115] The connectors can be two-piece connectors, a first piece comprising the flow restriction and a second piece comprising the first sealing mechanism.

[0116] The first and second sections can be interfaced.

[0117] The flow restriction can be upstream of the first sealing mechanism.

[0118] The assembly can further comprise a cavity defined by the first connector and the second connector.

[0119] The cavity can be defined by an outer arcuate surface of the first connector.

[0120] The cavity can be in fluid communication with the airflow passage via the access passage.

[0121] The cavity can have a longitudinal dimension which can be substantially parallel to a direction of airflow in the airflow passage.

[0122] The assembly can further comprise a second sealing mechanism arranged between the terminal and the access channel and / or the chamber.

[0123] The second sealing mechanism can comprise one or more of: a face seal, an O-ring, a lip seal, a dust seal, or a sealing surface.

[0124] The sealing surface can comprise an arcuate surface.

[0125] The sealing surface can be sealed via a friction / interference fit with an inner surface of a second connector.

[0126] The second connector can further comprise a stop.

[0127] The stop can be or can comprise a collar.

[0128] A surface of the collar can be configured to form a face seal with a surface of the second connector.

[0129] The first connector can have a pressure line which can be fluidically coupled to the orifice.

[0130] In a fifth aspect, there is provided a combination of a conduit and a connector according to any one of the first or second aspects.

[0131] The conduit can comprise a single-use conduit.

[0132] The conduit and connector can be integral.

[0133] The conduit and connector can be separate components which can be connected together.

[0134] The conduit can be or can comprise a dry line or conduit for directing a source of breathing gas to a humidification chamber or for providing to a breathing circuit or system.

[0135] The conduit and connector can be suitable for providing gas at a flow rate greater than or equal to about 5 or 10 litres per minute.

[0136] In a sixth aspect, there is provided a combination of a pressure relief valve and a connector according to the first aspect.

[0137] The pressure relief valve can be a reusable pressure relief valve.

[0138] The pressure relief valve and connector can be suitable for providing gas at a flow rate greater than or equal to about 5 or 10 litres per minute.

[0139] In a seventh aspect, a respiratory gas system is provided, comprising the connector of any one of the first through fourth aspects and a flow source adapted to provide gas at a flow rate greater than or equal to about 5 or 10 liters per minute.

[0140] In an eighth aspect, a pressure relief device for use in a respiratory system is provided, comprising a device inlet and a device outlet, a main gas flow passage between the device inlet and the device outlet, a pressure relief mechanism adapted to vent at least a portion of the gas flow when a pressure of the gas flow increases above a pressure threshold, and a sensing mechanism configured to dynamically adjust the pressure threshold. The outlet of the pressure relief device is configured to receive a connector. The operating condition of the pressure relief device is determined by the connector and comprises one of the following operating configurations: (a) the sensing mechanism operates to dynamically adjust the pressure threshold based on a flow rate and / or pressure of the gas flow of the pressure relief device or a portion of the respiratory system; (b) the sensing mechanism does not operate and the pressure threshold comprises a set pressure threshold; (c) the pressure relief valve and sensing mechanism do not operate and the pressure relief device delivers the gas flow to a patient without providing pressure relief.

[0141] The pressure relief device can further comprise a valve inlet in fluid communication with the device inlet, a vent outlet, a valve seat between the valve inlet and the vent outlet, and a valve member configured to seal against the valve seat and displace from the valve seat to vent at least a portion of the gas flow from the valve inlet to the vent outlet by an increase in an inlet pressure at the valve inlet above a pressure threshold.

[0142] In an embodiment, the sensing mechanism comprises a sensing member configured to sense a pressure differential indicative of a flow rate and / or pressure of the gas flow, and a mechanical linkage configured to couple the sensing member and the valve member to transfer a force exerted by the sensing member on the valve member to adjust a bias of the valve member against the valve seat in response to the flow rate and / or pressure of the gas flow.

[0143] In yet another aspect, an assembly is provided, comprising the pressure relief device of the eighth aspect and a connector. The connector is connected to the main outlet of the pressure relief device. The connector comprises an inlet end and an outlet end, a wall defining a connector gas flow passage between the inlet and outlet ends, a flow restriction, and an access passage through the wall. The sensing mechanism of the pressure relief device comprises a first sensing chamber in fluid communication with the gas flow upstream of the flow restriction, such that the operating configuration of the pressure device is operating configuration (a).

[0144] In yet another aspect, there is provided an assembly comprising the pressure relief device of the eighth aspect and a connector, wherein the connector is connected to the main outlet of the pressure relief device. The connector comprises an inlet end and an outlet end, a wall defining a connector gas flow passage between the inlet and outlet ends; a flow restriction; and an access passage through the wall. The sensing mechanism of the pressure relief device comprises a first sensing chamber in fluid communication with the gas flow upstream of the flow restriction and a second sensing chamber in fluid communication with the gas flow via the access passage at or downstream of the flow restriction, such that a resulting flow and / or pressure differential caused by the gas flow through the flow restriction is sensed by the sensing member, and the operating configuration of the pressure device is operating configuration (a).

[0145] The access passage can be positioned downstream of the flow restriction.

[0146] The access passage can be provided at the flow restriction, or immediately adjacent and on the downstream side of the flow restriction.

[0147] The flow restriction can be provided at or near the inlet end.

[0148] In yet another aspect, there is provided an assembly comprising the pressure relief device of the eighth aspect and a connector, wherein the connector is connected to the main outlet of the pressure relief device. The connector comprises an inlet end and an outlet end, a wall defining a connector gas flow passage between the inlet and outlet ends; and an access passage through the wall. The sensing mechanism of the pressure relief device comprises a first sensing chamber in fluid communication with the gas flow upstream of the connector and a second sensing chamber in fluid communication with the gas flow via the access passage, such that there is no resulting flow and / or pressure differential between the first sensing chamber and the second sensing chamber, and the operating configuration of the pressure device is operating configuration (b).

[0149] The pressure relief device can not include a flow restriction between the main inlet and the main outlet, and the connector can not include a flow restriction.

[0150] In an embodiment, the connector defines a gas flow passage having a substantially constant diameter.

[0151] The access passage can be substantially aligned with a communication line configured to fluidly connect the second sensing chamber to the gas flow through the connector.

[0152] In yet another aspect, there is provided an assembly comprising the pressure relief device of the eighth aspect and a connector, wherein the connector is connected to the main outlet of the pressure relief device. The connector comprises: an inlet end and an outlet end, and a wall defining a connector gas flow passage between the inlet and outlet ends. The sensing mechanism of the pressure relief device comprises a first sensing chamber in fluid communication with the gas flow upstream of the connector and a second sensing chamber blocked from fluid communication with the gas flow via the wall of the connector, such that there is no resulting flow and / or pressure differential between the first and second sensing chambers, and the operational configuration of the pressure device is operational configuration (c).

[0153] The connector can comprise an entry passage through the wall that is misaligned with a communication conduit configured to fluidly connect the second sensing chamber to the gas flow, such that the wall of the connector blocks the fluid communication between the sensing chamber and the gas flow.

[0154] In a ninth aspect, a pressure relief device for use in a respiratory system. The pressure relief device comprises: a device inlet and a device outlet; a main gas flow passage between the device inlet and the device outlet; and a pressure relief mechanism between the inlet and the outlet. The pressure relief mechanism comprises a substantially rigid valve connector portion configured to attach to a valve adjustment member; a valve diaphragm, a portion of which is overmoulded to the valve connector portion; and a valve seat. The valve diaphragm and / or the valve connector portion are arranged to be seated against the valve seat in a first configuration; and spaced apart from the valve seat in a second configuration when a pressure in the gas flow passage exceeds a pressure threshold.

[0155] The valve diaphragm and / or the valve connector portion can be adapted to seal against the valve seat in the first configuration.

[0156] In an embodiment, a tension in a portion of the valve diaphragm is greater in the second configuration than in the first configuration.

[0157] The device can comprise a valve frame, wherein a portion of the valve diaphragm is overmoulded to the valve frame.

[0158] In an embodiment, a portion of the valve diaphragm bridges the valve connector portion and the valve frame.

[0159] In an embodiment, a portion of the valve diaphragm between the valve connector portion and the valve frame is flexible.

[0160] The valve frame can be annular.

[0161] The valve frame can include one or both of an engagement feature and location features for attaching the valve frame to a body of the pressure relief device.

[0162] The valve connector portion can be substantially centrally located relative to the valve frame.

[0163] The device can include a sensing mechanism that dynamically adjusts the pressure threshold based on a flow rate of gas flow through the outlet.

[0164] The sensing mechanism can include a sensing diaphragm and a substantially rigid sensing connector portion attached to a valve adjustment member. A portion of the sensing diaphragm can be overmolded to the sensing connector portion.

[0165] The sensing mechanism can include a sensing frame, wherein a portion of the sensing diaphragm is overmolded to the sensing frame.

[0166] A portion of the sensing diaphragm can interface the sensing connector portion and the sensing frame.

[0167] In an embodiment, a portion of the sensing diaphragm between the sensing connector portion and the sensing frame is flexible.

[0168] The sensing frame can be annular.

[0169] The sensing frame can include one or both of an engagement feature and location features for attaching the sensing frame to a body of the pressure relief device.

[0170] The sensing connector portion can be substantially centrally located relative to the sensing frame.

[0171] The device can include a valve adjustment member, wherein the valve adjustment member includes a mechanical link that interfaces the sensing connector portion and the valve connector portion.

[0172] The sensing connector portion and the valve connector portion can each include an engagement feature for engaging an end of the mechanical link.

[0173] The mechanical link can include a plurality of ribs.

[0174] The mechanical link can be located in and axially slidable in a groove.

[0175] In an embodiment, the sensing connector portion, the valve connector portion, and the mechanical link are coaxial. An axis of the mechanical link can be substantially transverse to a general gas flow direction from the device inlet to the device outlet.

[0176] In an embodiment, the sensing connector portion and the valve connector portion each include a pair of spaced apart peripheral flanges. The flanges can be annular and coaxial, and each pair can define an annular space between the flanges.

[0177] In an embodiment, a portion of the valve diaphragm overmolded to the valve connector portion is received within the annular space defined by the flanges on the valve connector portion.

[0178] In an embodiment, a portion of the sensing diaphragm overmolded to the sensing connector portion is received within the annular space defined by the flanges on the sensing connector portion.

[0179] In an embodiment, a portion of the valve diaphragm and sensing diaphragm are under tension.

[0180] The valve diaphragm and / or sensing diaphragm can include an elastomeric material.

[0181] The pressure relief mechanism and / or the sensing mechanism can include removable components.

[0182] The device can include a first sensing chamber on a first side of the sensing diaphragm and a second sensing chamber on a second side of the sensing diaphragm, wherein the second sensing chamber is in fluid communication with a portion of the main gas flow passage between the device inlet and the device outlet or a gas flow passage in a breathing system downstream of a flow restriction or constraint, optionally the fluid communication between the second sensing chamber and the portion of the gas flow passage is provided by a spillway.

[0183] The device can include a first valve chamber on a side of the valve diaphragm opposite the seat, the first valve chamber having a hole in fluid communication with atmosphere.

[0184] In an embodiment, the first valve chamber hole includes a filter and / or the communication passage includes a filter.

[0185] The filter can include a porous material.

[0186] The device can include a housing. The housing can include two or more parts that are screwed or ultrasonically welded together.

[0187] In a tenth aspect, there is provided a diaphragm component for use in a pressure relief device, comprising: a flexible diaphragm and a substantially rigid connector portion configured to be attached to a valve adjustment member. A portion of the diaphragm is overmolded to the connector portion.

[0188] The connector portion can be adapted to be removably attached to the valve adjustment member.

[0189] The valve adjustment member can include a mechanical linkage, and the connector portion is attached to an end portion of the mechanical linkage.

[0190] In an embodiment, the connector portion includes a catch that engages a peripheral surface of the end portion of the mechanical linkage. The catch can include a protrusion that extends toward a central axis of the diaphragm member.

[0191] In an embodiment, the mechanical linkage includes at least one recess, and the protrusion engages the recess(es). The at least one recess can include an annular recess.

[0192] In an embodiment, the connector portion includes a boss.

[0193] In an embodiment, the connector portion includes a pair of spaced apart peripheral flanges. The flanges can be annular and coaxial, and each pair can define an annular space between the flanges.

[0194] In an embodiment, a portion of the diaphragm overmolded to the connector portion is received within the annular space defined by the flanges on the connector portion.

[0195] The diaphragm can be in tension, and / or the diaphragm can include an elastomeric material.

[0196] The diaphragm component can include a frame, wherein a portion of the diaphragm is overmolded to the frame.

[0197] In an embodiment, a portion of the diaphragm bridges the connector portion and the frame. The portion of the diaphragm between the connector portion and the frame can be flexible.

[0198] The frame can be annular.

[0199] The connector portion is substantially centrally positioned relative to the frame.

[0200] The frame can include one or both of an engagement feature and a positioning feature for attaching the frame to a valve body of the pressure relief device.

[0201] In an eleventh aspect, a pressure relief device is provided, comprising: a device inlet and a device outlet, a main gas flow passage between the device inlet and the outlet, a pressure relief valve comprising a valve diaphragm adapted to vent at least a portion of a gas flow through the gas flow passage when a pressure in the gas flow passage exceeds a pressure threshold, and a sensing mechanism dynamically adjusting the pressure threshold based on a flow rate and / or pressure of the gas flow through the gas flow passage. The sensing mechanism comprises a sensing diaphragm configured to sense a pressure differential indicative of the flow rate and / or pressure of the gas flow. A mechanical link couples the sensing diaphragm to the valve diaphragm to transfer a force exerted by the sensing diaphragm on the valve member to adjust a bias of the valve member against the valve seat in response to the flow rate and / or pressure of the gas flow. A damping arrangement is provided and configured to dampen mechanical oscillations of the valve diaphragm and / or the sensing diaphragm, wherein at least a portion of the arrangement is configured to be coupled to the mechanical link.

[0202] The damping arrangement can comprise a guide channel for the mechanical link, the guide channel comprising a viscous fluid in contact with the mechanical link. The viscous fluid can be sealed between the guide channel and the mechanical link to prevent gas flow along the guide channel.

[0203] In an embodiment, the viscous fluid is a lubricant having a high viscosity and a low shear strength. For example, the viscous fluid can comprise a non-Newtonian fluid. Additionally or alternatively, the viscous fluid can exhibit Bingham plasticity and / or dilatancy properties.

[0204] In an embodiment, the viscous fluid comprises a grease.

[0205] The sensing mechanism can comprise a first sensing chamber in fluid communication with the main gas flow passage. Further, the damping arrangement can comprise a sealed sheath substantially sealing against a portion of the mechanical link; and a passage providing fluid communication between the first sensing chamber of the sensing mechanism and the main gas flow passage. The passage can be defined by a damping orifice.

[0206] In an embodiment, the first sensing chamber is adjacent to the sensing diaphragm, wherein a wall of the sensing chamber comprises a link orifice through which the mechanical link passes.

[0207] In an embodiment, the sealed sheath covers the link orifice to provide a seal between the mechanical link and the first sensing chamber wall.

[0208] The device can include a guide channel between the sensing diaphragm and the valve diaphragm, wherein the mechanical link is axially slidable in the channel. The sealing sheath can be disposed at an end of the guide channel nearest the sensing diaphragm. Alternatively, the sealing sheath can be disposed at an end of the guide channel nearest the valve diaphragm.

[0209] The device can include a retention mechanism that retains the sealing sheath to the orifice or guide channel.

[0210] The sealing sheath can define an orifice or channel that receives the mechanical link. The sealing sheath can be flexible to allow the mechanical link to move axially through a range of motion.

[0211] In an embodiment, the sealing sheath is arcuate. For example, the sealing sheath can be convex relative to the first sensing chamber. Alternatively, the sealing sheath can include a pleated membrane.

[0212] The sealing sheath can allow the mechanical link to move axially through a range of motion to provide a desired range of adjustment of the bias of the diaphragm. Preferably, the sealing sheath provides negligible resistance to axial movement through the range of motion.

[0213] In an embodiment, the sealing sheath resists buckling under an axial load sufficient to adjust the valve mechanism.

[0214] The sensing mechanism can include a first sensing chamber in fluid communication with the main airflow passage, wherein the damping arrangement includes a magnetic arrangement to dampen mechanical oscillations of the pressure relief valve and / or the sensing mechanism.

[0215] The magnetic arrangement can include a conductive coil extending along a length of the mechanical link. The conductive coil can be electrically connected to a resistor to dissipate heat.

[0216] In an embodiment, the magnetic arrangement further includes a magnet disposed to induce a current in the coil upon axial movement of the mechanical link.

[0217] The device can include a magnet in the form of a ring disposed around the mechanical link.

[0218] In an embodiment, the magnetic arrangement includes a conductive member provided to the mechanical link. The conductive member can be in the form of a ring.

[0219] The electromagnetic arrangement can further include first and second magnets fixed relative to a body of the pressure relief device. The first and second magnets can be ring magnets arranged such that the mechanical link is axially movable within each ring. The first and second magnets are electromagnets or permanent magnets.

[0220] The magnetic arrangement can include a conductive coil and a conductive member encircling the mechanical link, the coil being fixed relative to the body of the pressure relief device. The coil can be electrically connected to a resistor to dissipate heat.

[0221] The pressure relief valve can include a valve inlet in fluid communication with the device inlet, a discharge outlet, a valve seat between the valve inlet and discharge outlet, and a valve diaphragm configured to seal against the valve seat and displace from the valve seat by an increase in inlet pressure at the valve inlet above the pressure threshold to discharge at least a portion of the gas flow from the valve inlet to the discharge outlet.

[0222] In a twelfth aspect, a pressure relief device is provided, including: a device inlet, a device outlet, a main gas flow passage between the inlet and the outlet, a pressure relief valve adapted to discharge at least a portion of a gas flow through the gas flow passage when a pressure in the gas flow passage exceeds a pressure threshold, and a sensing mechanism to dynamically adjust the pressure threshold based on a flow rate and / or pressure of the gas flow through the gas flow passage. The sensing mechanism includes a mechanical link coupling the pressure relief valve and the sensing mechanism. The sensing mechanism includes a first sensing chamber in fluid communication with the main gas flow passage and a sealing sheath substantially sealing against a portion of the mechanical link.

[0223] The pressure relief valve can include a valve diaphragm.

[0224] The sensing mechanism can include a sensing diaphragm.

[0225] The first sensing chamber can be adjacent the sensing diaphragm, wherein a wall of the sensing chamber includes a link aperture through which the mechanical link passes.

[0226] In an embodiment, the sealing sheath extends through the aperture to provide a seal between the mechanical link and the sensing chamber wall.

[0227] The device can include a guide channel between the sensing diaphragm and the valve diaphragm, wherein the mechanical link is axially slidable in the channel. The guide channel can define the link aperture.

[0228] The sealing sheath can be disposed at an end of the guide channel nearest the sensing diaphragm. Alternatively, the sealing sheath can be disposed at an end of the guide channel nearest the valve diaphragm, or intermediate an end of the guide channel nearest the valve diaphragm and an end of the guide channel nearest the sensing diaphragm.

[0229] The device can include a retention mechanism that retains the sealing sheath to the orifice or guide channel.

[0230] The sealing sheath can define an orifice or channel that receives the mechanical linkage.

[0231] The sealing sheath can seal around the mechanical linkage.

[0232] In an embodiment, the sealing sheath is flexible to allow axial movement of the mechanical linkage through a range of movement.

[0233] The sealing sheath can be arcuate. For example, the sealing sheath can be convex relative to the first sensing chamber. Alternatively, the sealing sheath can include a pleated membrane. The sealing sheath preferably provides negligible resistance to axial movement through the range of movement and / or the sealing sheath resists buckling under axial loads sufficient to adjust the valve mechanism.

[0234] The sealing sheath can allow axial movement of the mechanical linkage through a range of movement to provide a desired range of adjustment of the bias of the diaphragm.

[0235] The sensing mechanism can include a sensing diaphragm, the first sensing chamber being adjacent the sensing diaphragm. The wall of the first sensing chamber further includes a damping orifice in fluid communication between the first sensing chamber and the main gas flow passage.

[0236] The wall of the first sensing chamber can include a plurality of damping orifices.

[0237] The sensing mechanism includes a second sensing chamber on a side of the sensing diaphragm opposite the first sensing chamber, wherein the second sensing chamber is in fluid communication with a portion of the main gas flow passage between the device inlet and the device outlet or a gas flow passage in a breathing system downstream of a flow restriction / constraint, optionally the fluid communication between the second sensing chamber and the portion of the gas flow passage is provided by a communication conduit.

[0238] A valve seat can be positioned on one side of the valve diaphragm and a valve chamber is positioned on the opposite side. The one side of the valve diaphragm can be configured to seal against the valve seat, wherein the valve chamber is in fluid communication with atmosphere via an aperture.

[0239] The aperture can include a filter and / or the communication conduit can include a filter. The filter can include a porous material.

[0240] The device can include a main body that defines the device inlet and outlet.

[0241] The device can include two caps configured to cooperate to house the pressure relief device, the two caps being screwed or ultrasonically welded together.

[0242] In a thirteenth aspect, a pressure relief device is provided, comprising: a device inlet, a device outlet, a gas flow passage between the device inlet and the outlet, a pressure relief valve adapted to vent at least a portion of a gas flow through the gas flow passage when a pressure in the gas flow passage exceeds a pressure threshold, and a sensing mechanism to dynamically adjust the pressure threshold based on a flow rate and / or pressure of the gas flow through the gas flow passage. The sensing mechanism includes a viscous fluid to dampen mechanical oscillations of the pressure relief valve and / or the sensing mechanism, and wherein the sensing mechanism includes a first sensing chamber in fluid communication with the main gas flow passage.

[0243] The pressure relief valve can include a valve diaphragm and / or the sensing mechanism includes a sensing diaphragm. In an embodiment, the device includes a mechanical linkage coupling the valve diaphragm and the sensing diaphragm.

[0244] The device can include a guide channel between the sensing diaphragm and the valve diaphragm, wherein the mechanical linkage is axially slidable in the channel.

[0245] In an embodiment, the viscous fluid is provided in the guide channel to dampen movement of the mechanical linkage. The viscous fluid can be sealed between the guide channel and the mechanical linkage to prevent gas flow along the guide channel. The viscous fluid can include a lubricant having a high viscosity and a low shear strength. For example, the viscous fluid can include a non-Newtonian fluid and / or exhibit Bingham plasticity and / or dilatant properties. For example, the viscous fluid can include grease.

[0246] The first sensing chamber can include a damping orifice providing fluid communication between the first sensing chamber and the main gas flow passage. The first sensing chamber can include a plurality of damping orifices.

[0247] The sensing mechanism can include a second sensing chamber on an opposite side of the sensing diaphragm from the first sensing chamber. The second sensing chamber can be in fluid communication with a portion of a gas flow passage downstream of a flow restriction / constraint in the main gas flow passage between the device inlet and device outlet or in a gas flow passage in a respiratory system. Optionally, the fluid communication between the second sensing chamber and the portion of the gas flow passage is provided by a communication conduit.

[0248] The device can include a valve seat positioned on one side of the valve diaphragm and a valve chamber on the opposite side. The one side of the valve diaphragm can be configured to seal against the valve seat, and the valve chamber can be in fluid communication with the atmosphere via a hole.

[0249] The hole can include a filter and / or the communication line can include a filter. The filter can include a porous material.

[0250] The device can include a valve body defining the device inlet and outlet. The device can include two caps configured to cooperate to house the pressure relief device, the caps being screwed or ultrasonically welded together.

[0251] In a fourteenth aspect, a pressure relief device is provided, including: an inlet, an outlet, a gas flow passage between the inlet and the outlet, a pressure relief valve adapted to vent at least a portion of a gas flow through the gas flow passage when a pressure in the gas flow passage exceeds a pressure threshold, a sensing mechanism to dynamically adjust the pressure threshold based on a flow rate and / or pressure of the gas flow through the gas flow passage, and a magnetic arrangement to dampen mechanical oscillations of the pressure relief valve and / or the sensing mechanism.

[0252] The pressure relief valve can include a valve diaphragm and / or the sensing mechanism includes a sensing diaphragm. A mechanical link can couple the pressure relief valve and the sensing mechanism. A guide groove or guide orifice can be provided between the sensing diaphragm and the valve diaphragm, wherein the mechanical link is axially slidable in the guide groove.

[0253] In an embodiment, the magnetic arrangement can include a conductive coil extending along a length of the mechanical link. The conductive coil can be electrically connected to a resistor to dissipate heat.

[0254] The magnetic arrangement can further include a magnet arranged to induce a current in the coil upon axial movement of the mechanical link. The magnet can be in the form of a ring surrounding the mechanical link.

[0255] The magnetic arrangement can include an electrically conductive member provided to the mechanical link. The electrically conductive member can be in the form of a ring.

[0256] In an embodiment, the electromagnetic arrangement further includes first and second magnets fixed relative to a body of the pressure relief device. The first and second magnets can include ring magnets arranged such that the mechanical link is axially movable within each ring. The first and second magnets can be electromagnets or permanent magnets.

[0257] The magnetic arrangement can include a conductive coil and a conductive member encircling the mechanical linkage, the coil being fixed relative to the body of the pressure relief device. The coil can be electrically connected to a resistor to dissipate heat.

[0258] The device can include a sensing chamber on one side of the sensing diaphragm opposite the mechanical member, wherein the second sensing chamber is in fluid communication with a portion of the main gas flow passage downstream of the flow restriction / constraint between the device inlet and the device outlet or a gas flow passage in a breathing system. Optionally the fluid communication between the second sensing chamber and the portion of the gas flow passage can be provided by a communication conduit.

[0259] The device can include a valve seat positioned on one side of the valve diaphragm and a valve chamber on the opposite side, wherein the one side of the valve diaphragm is configured to seal against the valve seat; and wherein the valve chamber is in fluid communication with atmosphere via an aperture.

[0260] The aperture can include a filter and / or the communication conduit can include a filter. The filter includes a porous material.

[0261] The device can include a housing. The housing can include two or more parts that are screwed or ultrasonically welded together.

[0262] In a fifteenth aspect, there is provided a breathing system including a flow source, a pressure relief device as described above, and a patient interface. Gas from the flow source flows to the patient interface via the pressure relief device.

[0263] In an embodiment, the system includes a humidifier positioned between the flow source and the patient interface. The humidifier can be positioned downstream of the pressure relief device, with a conduit connecting the outlet of the pressure relief device to an inlet of the humidifier.

[0264] An inspiratory conduit can be provided between the humidifier and the patient interface.

[0265] The pressure relief device can be coupled to the flow source.

[0266] In use, the pressure relief device can be oriented such that the diaphragm is substantially perpendicular relative to a ground surface.

[0267] The pressure relief device can include a flange at the device inlet.

[0268] A connector as described above can be provided at the outlet of the pressure relief device.

[0269] In one embodiment, the patient interface includes a nasal cannula. The cannula can include a non-sealing nasal cannula. The nasal cannula can be switchable between two configurations, where in a first configuration the nasal cannula delivers a first flow of gas to a patient, and in a second configuration the nasal cannula delivers a second flow of gas to the patient, where the first and second flows are different.

[0270] The second flow can be lower than the first flow.

[0271] The second flow can be substantially free of flow to the nasal cannula.

[0272] The terms 'tube' and 'pipe' as used in the specification and claims are intended to broadly mean any member forming or providing a flow for conducting a flow of liquid or gas, unless the context otherwise requires. For example, a tube or tube portion can be part of a humidification device, or can be a separate tube that can be attached to a humidification device to provide a flow or fluid communication of fluid.

[0273] The terms 'comprise' and / or 'comprising', as used in the specification and claims, mean 'consisting at least in part of'. When interpreting each statement in the specification and claims where this term is used, said features other than those of the specific claim statement can also be present. Related terms such as 'comprises', 'comprising', are to be interpreted in the same manner.

[0274] It is intended that references to numerical ranges, for example 1 to 10, disclosed herein also include references to all rational numbers within that range, for example 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10, and any range of rational numbers within that range, for example 2 to 8, 1.5 to 5.5 and 3.1 to 4.7, and therefore all sub-ranges of all ranges explicitly disclosed herein are hereby expressly incorporated by reference. These are merely examples of what is specifically intended, and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.

[0275] As used herein, the term 'and / or' means 'and' or 'or', or both.

[0276] As used herein, the term '(s)' following a noun means the plural and / or singular form of the noun.

[0277] Many modifications, variations, and alternatives to the structure of the present application will occur to those skilled in the art upon reading of the foregoing description, and it is intended to show the inventive concept herein by way of illustration. Any and all modifications, variations, or alternatives, as they occur to those skilled in the art, are intended to be included herein.

[0278] The present disclosure is directed to the foregoing, and also contemplates the following structures which are given by way of example only. The features disclosed can be combined in new embodiments to resolve mutually exclusive, or related, inventive concepts. BRIEF DESCRIPTION OF DRAWINGS

[0279] The preferred embodiments of the present disclosure are described herein with reference to the following figures.

[0280] According to the detailed description of the reference herein below with reference to the following drawings, specific embodiments and their alterations will be apparent to those skilled in the art, in which:

[0281] Figure 1A A high flow respiratory system is illustrated.

[0282] Figure 1B A schematic representation of a flow controlled pressure relief valve.

[0283] Figure 1C A perspective view of a connector and a flow controlled pressure relief or pressure regulating device of one embodiment.

[0284] Figure 2 A perspective view of a connector and a flow controlled pressure relief or pressure regulating device of Figure 1C

[0285] A perspective view of a connector and a flow controlled pressure relief or pressure regulating device of Figure 3 Figure 2 A perspective view of a connector and a flow controlled pressure relief or pressure regulating device of

[0286] Figure 4 A perspective view of a connector and a flow controlled pressure relief or pressure regulating device of

[0287] Figure 5 Figure 4 A perspective view of a connector and a flow controlled pressure relief or pressure regulating device of

[0288] Figure 6 A perspective view of a connector and a flow controlled pressure relief or pressure regulating device of

[0289] Figure 7 A perspective view of a connector and a flow controlled pressure relief or pressure regulating device of Figure 6

[0290] A perspective view of a connector and a flow controlled pressure relief or pressure regulating device of Figure 8 ​​​

[0291] Figure 9 is Figure 7 a cross-sectional view of one variant of the connector and the second connector.

[0292] Figure 10 is Figure 7 a cross-sectional view of another variant of the connector and the second connector.

[0293] Figure 11 is Figure 10 a perspective cross-sectional view of the connector and the second connector.

[0294] Figure 12 is Figure 7 a cross-sectional view of the connector.

[0295] Figure 13 is a cross-sectional view of another embodiment connector and flow controlled pressure relief or pressure regulation device.

[0296] Figure 14 is a cross-sectional view of another embodiment connector and flow controlled pressure relief or pressure regulation device.

[0297] Figure 15 is a schematic cross-sectional view of another embodiment connector and flow controlled pressure relief or pressure regulation device.

[0298] Figure 16 is a cross-sectional view of another embodiment connector and flow controlled pressure relief or pressure regulation device.

[0299] Figure 17 is a cross-sectional view of another embodiment connector and flow controlled pressure relief or pressure regulation device.

[0300] Figure 18 is a cross-sectional view of another embodiment connector and flow controlled pressure relief or pressure regulation device.

[0301] Figure 19 is a cross-sectional view of another embodiment connector and flow controlled pressure relief or pressure regulation device.

[0302] Figure 20 illustrates a tuning procedure for FCPRV.

[0303] Figure 21 is a perspective view of yet another embodiment connector.

[0304] Figure 22 is a side view of the connector of Figure 21

[0305] Figure 23 is a cross-sectional view of the connector of Figure 21 and 22 is a cross-sectional view of the connector of​

[0306] Figure 24 is a cross-sectional view of one embodiment pressure relief device having two diaphragm components.

[0307] Figure 25 is a top perspective view of one embodiment diaphragm component for use in a pressure relief device, such as the pressure relief device shown in Figure 24

[0308] Figure 26 is a bottom perspective view of the diaphragm component of Figure 21

[0309] Figure 27 is a side view taken through line A-A of Figure 26

[0310] Figure 28 is a side view taken through line A-A of Figure 26 , but showing only the flexible diaphragm of the diaphragm component, with the frame and link connectors hidden.

[0311] Figure 29A is a bottom plan view of the diaphragm component.

[0312] Figure 29B is a top plan view of the diaphragm component of Figure 29A

[0313] Figure 30 is a perspective view of one embodiment pressure relief device, with the valve chamber cap and coupler hidden.

[0314] Figure 31 is a side view of the pressure relief device of Figure 30 , with the cross-section taken along the centerline of the device.

[0315] Figure 32 is a detailed perspective view of a portion of Figure 31 , showing the damping orifice and the seal sheath.

[0316] Figure 33A is a perspective view of the seal sheath of Figure 31 and 32 .

[0317] Figure 33B is a side view taken through the centerline of the seal sheath of Figure 33A

[0318] Figure 34 is a perspective cross-sectional view of yet another embodiment pressure relief valve, with the valve chamber cap hidden and the cross-section taken along the centerline of the device.

[0319] Figure 35 is a perspective view of a portion of​​​​​Figure 30 Side view.

[0320] Figure 36 This is a schematic diagram of the arrangement for the movement of an electromagnetically damped mechanical link, wherein the mechanical link includes a conduction coil.

[0321] Figure 37 This is a schematic diagram of another arrangement for the movement of an electromagnetically damped mechanical link, wherein the mechanical link includes a conduction ring.

[0322] Figure 38 yes Figure 25 A perspective view of the pressure relief valve, showing the valve chamber cap.

[0323] Figure 39 yes Figure 38 A perspective view of one of the valve chamber caps, showing the fastener holes used to join the two chamber caps together.

[0324] Figure 40 Figure 33 is a perspective view of the pressure relief valve in use with its orientation vertical, where the inlet is coupled to the gas supply and outlet.

[0325] Figure 41 It is a side view of a pressure relief device with an alternative sealing sleeve and a damping orifice arrangement, wherein the section is taken along the centerline of the device.

[0326] Figure 42 yes Figure 41 Detailed view of F42.

[0327] Figure 43 This is a side view of yet another pressure relief device with an alternative sealing sleeve and damping orifice arrangement, wherein the section is taken along the centerline of the device.

[0328] Figure 44 yes Figure 43 Detailed view of F44.

[0329] Figure 45 This is a side view of another pressure relief device with a connector having a sensing orifice located adjacent to and downstream of the flow restriction.

[0330] Figure 46 It corresponds to Figure 45 A perspective sectional view.

[0331] Figure 47 This is a side view of another pressure relief device with a connector having a sensing orifice provided at the flow restriction point.

[0332] Figure 48 It corresponds to Figure 47 A perspective sectional view.

[0333] Figure 49 Figure 9 is a partial perspective view showing the connection between the connector portion of yet another embodiment valve member and one end of a mechanical linkage.

[0334] Figure 50 is a partial cross-sectional view through Figure 49 the connector portion of the valve member of Figure 8 and a mechanical linkage. DETAILED DESCRIPTION

[0335] Various embodiments are described with reference to the accompanying drawings. Throughout the drawings and the specification, like reference numerals can be used to designate the same or similar components, and redundant description can be omitted.

[0336] Connectors according to embodiments described herein are particularly suitable for use in respiratory systems such as CPAP or high flow respiratory gas systems, for example high flow systems used in anaesthesia procedures. Respiratory systems in which the connectors can be particularly useful are CPAP, BiPAP, high flow therapy, variable high flow therapy, low flow air, low flow 02 delivery, bubble CPAP, apnoea high flow (i.e. high flow to anaesthetised patients), invasive ventilation and non-invasive ventilation. In addition, the connectors as described herein can be used in systems other than respiratory systems. Connectors according to embodiments described herein are particularly suitable for use with pressure relief or regulation devices.

[0337] Unless otherwise indicated by context, a flow source provides a flow of gas at a set flow rate. The set flow rate can be a constant flow rate, a variable flow rate, or can be an oscillating flow rate, for example a sinusoidal flow rate or a flow rate having a stepped or square wave profile. Unless otherwise indicated by context, a pressure source provides a flow of gas at a set pressure. The set pressure can be a constant pressure, a variable pressure, or can be an oscillating pressure, for example a sinusoidal pressure or a pressure having a stepped or square wave profile.

[0338] ‘High flow therapy’ as used in the present disclosure can refer to the delivery of gas to a patient at a flow rate greater than or equal to about 5 or 10 litres per minute (5 or 10 LPM or L / min).

[0339] In some configurations, 'high flow therapy' can refer to delivery of gas to a patient at a flow rate of about 5 or 10 LPM to about 150 LPM, or about 15 LPM to about 95 LPM, or about 20 LPM to about 90 LPM, or about 25 LPM to about 85 LPM, or about 30 LPM to about 80 LPM, or about 35 LPM to about 75 LPM, or about 40 LPM to about 70 LPM, or about 45 LPM to about 65 LPM, or about 50 LPM to about 60 LPM. For example, in accordance with various embodiments and configurations described herein, the flow rate of gas supplied or provided to an interface via a system or from a flow source can include, but is not limited to, a flow rate of at least about 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150 LPM or more, and useful ranges can be selected to be any of these values (e.g., about 20 LPM to about 90 LPM, about 40 LPM to about 70 LPM, about 40 LPM to about 80 LPM, about 50 LPM to about 80 LPM, about 60 LPM to about 80 LPM, about 70 LPM to about 100 LPM, about 70 LPM to about 80 LPM).

[0340] The delivered gas will be selected depending on the intended use of the therapy. The delivered gas can include a percentage of oxygen. In some configurations, the percentage of oxygen in the delivered gas can be about 15% to about 100%, 20% to about 100%, or about 30% to about 100%, or about 40% to about 100%, or about 50% to about 100%, or about 60% to about 100%, or about 70% to about 100%, or about 80% to about 100%, or about 90% to about 100%, or about 100%, or 100%.

[0341] In some embodiments, the delivered gas can include a percentage of carbon dioxide. In some configurations, the percentage of carbon dioxide in the delivered gas can be more than 0%, about 0.3% to about 100%, about 1% to about 100%, about 5% to about 100%, about 10% to about 100%, about 20% to about 100%, or about 30% to about 100%, or about 40% to about 100%, or about 50% to about 100%, or about 60% to about 100%, or about 70% to about 100%, or about 80% to about 100%, or about 90% to about 100%, or about 100%, or 100%.

[0342] High flow therapy has been found to be effective in meeting or exceeding a patient's normal actual inspiratory demand to increase the patient's supply of oxygen and / or reduce the work of breathing. In addition, high flow therapy can create a flushing effect in the nasopharynx such that the anatomic dead space of the upper airways is flushed by the high incoming airflow. This creates a reservoir of fresh gas available for each breath while minimizing rebreathing of carbon dioxide, nitrogen, etc.

[0343] By way of example, reference is made to Figure 1A A high flow respiratory system 10 is described. High flow therapy can be used as a means to facilitate gas exchange and / or respiratory support through the delivery of oxygen and / or other gases and through the removal of CO2from the patient's airways. High flow therapy can be particularly useful prior to, during, or after a medical procedure.

[0344] When used prior to a medical procedure, the high airflow is able to preload the patient with oxygen such that their blood oxygen saturation levels and the volume of oxygen in their lungs is higher to provide a buffer of oxygen when the patient is in an apneic phase during the medical procedure.

[0345] A continuous supply of oxygen is necessary to maintain healthy respiratory function during medical procedures where respiratory function can fall below standard (e.g., weaken or stop), such as during anesthesia. When such supply falls below standard, hypoxia and / or hypercapnia can occur. During medical procedures where the patient is unconscious, such as anesthesia and / or general anesthesia, the patient is monitored to detect when such conditions occur. If the oxygen supply and / or CO2removal falls below standard, the clinician stops the medical procedure and facilitates the oxygen supply and / or CO2removal. This can be achieved, for example, by manually ventilating the patient through an anesthesia bag and mask or by using a high flow therapy system to provide a high airflow to the patient's airways.

[0346] Further advantages of the high airflow can include that the high airflow increases the pressure in the patient's airways, thereby providing pressure support to open the airway, trachea, lungs / alveoli, and bronchioles. The opening of these structures improves oxygen supply and, to some extent, helps removal of CO2.

[0347] The increased pressure can also prevent structures such as the larynx from blocking the view of the vocal cords during intubation. When humidified, the high airflow can also prevent airway drying, reduce mucociliary damage, and reduce the risk of laryngospasm and risks associated with airway drying such as nosebleeds, suctioning (due to nosebleeds), and airway obstruction, swelling, and bleeding. Another advantage of the high airflow is that the flow can clear the airway of smoke produced during surgical procedures. For example, smoke can be produced by laser and / or cauterizing devices.

[0348] Pressure relief or regulation devices are particularly feasible for use in respiratory systems, such as high flow systems that include unsealed patient interfaces, to provide a pressure upper limit for the system. Most importantly, the pressure upper limit can be configured to provide a patient safety limit, or can be configured to prevent damage to tubes, fluid connections, or other components. Pressure relief or regulation devices can be used to regulate the pressure provided to a patient in a sealed system, such as a CPAP (continuous positive airway pressure), BiPAP (bilevel positive airway pressure), and / or bubble CPAP system.

[0349] Reference is made to Figure 1A , the system / device 10 can include an arrangement of integrated or separate components as generally shown in dashed box 11 in Figure 1A . In some configurations, the system 10 can include a modular arrangement of components. Hereinafter, the system / device 10 will be referred to as a system, but this should not be considered limiting. The system 10 can include a flow source 12, such as a wall-embedded oxygen source, an oxygen tank, a blower, a flow therapy device, or any other oxygen or other gas source. The system 10 can also include an additive gas source 12a that includes one or more other gases that can be combined with the flow source 12. The flow source 12 can provide a pressurized high flow of gas 13 that can be delivered to a patient 16 via a delivery conduit 14 and a patient interface 15, such as a nasal cannula. A controller 19 controls the flow source 12 and the additive gas source 12a, by way of valves or the like, to control the flow and other characteristics, such as any one or more of the pressure, composition, concentration, volume of the high flow gas 13. A humidifier 17 can also be optionally provided that can humidify and control the temperature of the gas under the control of the controller. One or more sensors 18a, 18b, 18c, 18d, such as flow, oxygen, pressure, humidity, temperature, or other sensors, can be placed throughout the system and / or at, on, or near the patient 16. The sensors can include a pulse oximeter 18d on the patient for determining the oxygen concentration in the blood.

[0350] The controller 19 can be coupled to the flow source 12, the addition gas source 12a, the humidifier 17, and the sensors 18a-18d. The controller 19 can operate the flow source to provide the delivered gas flow. It can control the flow, pressure, composition (where more than one gas is being provided), volume, and / or other parameters of the gas provided by the flow source based on feedback from the sensors. The controller 19 can also control any other suitable parameters of the flow source to meet the oxygenation requirements. The controller 19 can also control the humidifier 17 based on feedback from the sensors 18a-18d. Using input from the sensors, the controller can determine the oxygenation requirements and control the parameters of the flow source 12 and / or the humidifier 17 as needed. An input / output (I / O) interface 20 (such as a display and / or input device) is provided. The input device is for receiving information from a user (e.g., a clinician or patient) that can be used to determine the oxygenation requirements. In some embodiments, the system can be without a controller and / or I / O interface. A medical professional (such as a nurse or technician) can provide the necessary control functions.

[0351] The pressure can also be controlled. As mentioned above, a high gas flow (optionally humidified) can be delivered to the patient 16 via the delivery conduit 14 and the patient interface 15 or an ‘interface’ such as a cannula, mask, nasal interface, oral device, or combination thereof. In some embodiments, a high gas flow (optionally humidified) can be delivered to the patient 16 for surgical use, e.g., surgical insufflation ventilation. In these embodiments, the ‘interface’ can be a surgical cannula, sleeve, or other suitable interface. The patient interface can be substantially sealed, partially sealed, or substantially unsealed. As used herein, a nasal interface is a device such as a cannula, nasal mask, nasal pillow, or other type of nasal device or combination thereof. A nasal interface can also be used in conjunction with a mask or oral device (such as a tube inserted into the mouth) and / or a mask or oral device (such as a tube inserted into the mouth) that can be detached and / or attached to the nasal interface. A nasal cannula is a nasal interface that includes one or more prongs configured to be inserted into a patient’s nares. A mask refers to an interface that covers a patient’s nares and / or mouth and can also include a partially removable device that covers a patient’s mouth, or other patient interface such as a laryngeal mask airway or endotracheal tube. A mask also refers to a nasal interface that includes nasal pillows that create a substantially seal with a patient’s nares. The controller controls the system to provide the required oxygenation.

[0352] The system 10 according to embodiments herein comprises a pressure relief or regulating device, or pressure limiting device 100 (herein a pressure relief valve or PRV). The pressure limiting device 100 can be a valve having features described in WO / 2018 / 033863, the entire contents of which are incorporated herein by reference. The connector can be used with other valves and / or devices. The PRV can be placed anywhere in the system between the flow source 12 and the patient 16. Preferably, the PRV 100 is provided at the outlet of the flow source 12, or between the flow source 12 and the humidifier 17, e.g. near the inlet of the humidifier 17. In some embodiments, the PRV 100 can be provided at the outlet of the humidifier 17 and / or the inlet to the conduit 14, or at any point along the conduit 14 through a suitable housing or coupling device. The PRV 100 can be located anywhere in the system, for example the PRV can be part of the patient interface 15. The system can additionally or alternatively comprise a flow controlled pressure relief or pressure regulating device (FCPRV).

[0353] The PRV 100 according to the present disclosure regulates pressure at almost constant pressure across a given flow range. The PRV 100 can be used to provide an upper limit for patient safety, and / or to prevent damage to system components caused by overpressure. For example, an occlusion in the system can cause a large amount of back pressure in the system upstream of the occlusion, and the PRV can operate to ensure that the back pressure does not pressurise above a limit that protects the patient and / or system components from damage. An occlusion in the patient’s nares or expiratory conduit can result in increased patient pressure. An occlusion in the system can be caused by, for example, accidental folding or creasing of the conduit 14, or can be caused deliberately, for example by occluding the conduit 14 (e.g. by pinching a portion of the conduit) to prevent airflow to the patient.

[0354] Figure 1C and 2 One embodiment PRV is shown included in a flow controlled pressure regulating valve (FCPRV) 100, in which the PRV is located at the outlet of the flow source 12, in which the FCPRV 100 is located between the flow source 12 and the humidifier 17, and in which the FCPRV 100 is located at the inlet of the conduit 14. Figure 1BA flow controlled pressure regulating valve (FCPRV) 100 is shown in FIG. 1. The PRV includes an inlet 101, an outlet chamber 102 having an outlet 103, a valve seat 104 between the inlet 101 and the outlet chamber 102, and a valve member 105 biased to seal against the valve seat 104. The valve member 105 is adapted to displace from the valve seat as a result of an increase in pressure Pc at the PRV inlet 101 above a pressure threshold. The pressure Pc acts on the valve member 105 to force the member away from the valve seat 104 once the pressure Pc reaches or exceeds the threshold. When the valve member 105 is displaced from the valve seat 104, gas flow from the inlet 101 into the outlet chamber 102, and then from the outlet chamber 102 to ambient / atmospheric pressure via the outlet 103. The outlet from the chamber is configured such that gas flow through the outlet causes a (back) pressure Pb in the outlet chamber acting on the valve member 105 to displace the valve member 105 further from the valve seat 104. When the valve member 105 is displaced further from the valve seat 104, the gap between the valve member 105 and the valve seat 104 increases.

[0355] The FCPRV 100 further includes a sensing mechanism 150 to dynamically adjust the pressure threshold of the PRV 100 discharge pressure based on the flow and / or pressure of gas or a portion thereof through the FCPRV or respiratory system. In certain embodiments, the FCPRV 100 includes a sensing mechanism 150 to dynamically adjust the pressure threshold of the PRV 100 discharge pressure based on the flow of gas or a portion thereof through the FCPRV or respiratory system. In certain embodiments, the FCPRV 100 includes a sensing mechanism 150 to dynamically adjust the pressure threshold of the PRV 100 discharge pressure based on the pressure of gas or a portion thereof through the FCPRV or respiratory system. A connector 200 according to embodiments described herein can be used with the FCPRV 100.

[0356] Reference is made to Figure 1B and 2 The features and functionality of the FCPRV will now be described. The FCPRV 100 includes a main body 110 defining a main inlet 151 and a main outlet 153. In the illustrated embodiment, the sensing mechanism 150 includes a flow restriction or flow restriction 152 between the main inlet 151 and the main outlet 153 of the FCPRV. The main inlet 151 and / or the main outlet 153 are preferably integral with or defined by the FCPRV main body 110. In the illustrated embodiment, the flow restriction 152 is a flow restriction orifice. In other embodiments, the flow restriction 152 can be a flow restriction orifice, a flow restriction valve, or a flow restriction pinhole. Figure 1B and 2In embodiments, the flow restriction 152 is part of the FCPRV body. In later described embodiments, the flow restriction is part of the connector. For ease of reference, the term 'flow restriction' can be used herein to describe both flow restrictions such as orifice plates and flow constraints such as used in venturi. In operation, gas flow in the breathing system passes through the FCPRV 100 from the main inlet 151 to the main outlet 153. The sensing mechanism 150 senses the flow / pressure of gas to the patient at or downstream of the flow restriction / constraint. In the illustrated embodiment, the relief valve inlet 101 is between the FCPRV main inlet 151 and the main outlet 153, and the flow restriction / constraint is downstream of the PRV inlet but upstream of the main outlet 153. The sensing mechanism 150 senses the flow / pressure of gas to the patient at or through the main outlet 153 of the valve.

[0357] The sensing mechanism 150 also includes a sensing chamber 154 and a sensing member 155 located in the sensing chamber 154. The sensing member 155 divides the sensing chamber 154 into a first chamber 154a and a second chamber 154b. The first chamber 154a is in fluid communication with the gas flow upstream of the flow restriction 152, for example the first chamber 154a is in fluid communication with the main inlet 151 and the valve inlet 101 upstream of the restriction 152. The second chamber 154b is in fluid communication with the gas flow at or downstream of the flow restriction 152. In some embodiments, the device includes a flow constraint configured as a venturi, where the second chamber 154b is in fluid communication with the constraint via a pressure 'tap' or communication line 156. Figure 1B ) with the constraint. However, in alternative configurations, the device can include a flow restriction 152, for example an orifice plate, and the first and second chambers can tap either side of the orifice plate, for example via the pressure 'tap' or communication line 111 shown in Figure 2 The pressure differential can be generated in any other suitable manner, for example by a permeable membrane or filter having a known pressure drop (flow restriction).

[0358] The resulting pressure drop caused by the gas flow through the restriction 152 from the main inlet 151 to the main outlet 153 of the device is thus sensed by the sensing member 155 located within the sensing chamber 154.

[0359] To increase the flow through the respiratory system, the pressure provided by the flow source 12 is increased, thereby increasing the pressure at the main inlet 151 and in the first chamber 154a of the sensing chamber 154. As the flow through the FCPRV increases, a greater pressure drop is generated by the restriction 152 due to the increased velocity of the gas passing through the restriction 152, and the pressure Pv in the second chamber 154b of the sensing chamber 154 decreases. Thus, the increased flow through the FCPRV 100 from the main inlet 151 to the main outlet 153 results in an increased pressure differential across the sensing member 155, with the first chamber 154a being the high (higher) pressure side of the sensing chamber 154 and the second chamber 154b being the low (lower) pressure side of the sensing chamber 154. This causes the sensing member 155 to move towards the low pressure side of the sensing chamber 154, away from the PRV valve member 105.

[0360] The sensing member 155 is mechanically coupled to the valve member 105 of the pressure relief valve 100, such that as the sensing member 155 moves towards the lower pressure side of the sensing chamber 154, the sensing member 155 pulls or biases the valve member 105 of the PRV against the valve seat 104. For a given flow setting, a higher flow causes a higher pressure differential across the sensing member 155, further biasing the valve member 105 towards the valve seat 104. This causes the pressure relief threshold for the PRV to increase. If a flow restriction is introduced (e.g. a pinched conduit 14 or a blockage in the patient's nares), the flow source 12 adjusts (rapidly) to increase the pressure in the system to maintain the flow at the desired level. If the system pressure required to achieve the desired flow is above the relief pressure, the PRV starts to bleed off, where a portion of the flow provided to the main inlet 151 is bled off via the PRV valve member 105, and a portion of the flow passes through the restriction 152 and from the main outlet 153. The flow source 12 maintains the set flow to the main inlet 151 of the FCPRV 100. Thus, as the PRV starts to bleed off, the flow through the restriction or restriction 152 decreases, and the pressure differential acting on the sensing member 155 decreases. This causes the bias provided by the sensing member 155 to the valve member 105 to decrease, and thus the pressure relief threshold for the PRV 100 to decrease. In an ideal situation, a state of equilibrium will be reached whereby the patient receives as much flow as possible without exceeding the pressure relief threshold or without exceeding the maximum delivery pressure at the patient interface.

[0361] If the flow restriction completely (or substantially completely) blocks the system, e.g. the conduit 14 is completely occluded (completely pinched or clamped) or the patient's nares are completely blocked, all or substantially all of the flow delivered to the main inlet 151 of the FCPRV 100 is bled off via the PRV valve member 105.

[0362] Figure 1BThe body of a first chamber 154a that provides or forms the oral cavity 102 and the sensing chamber 154 is shown. Those features are not shown in other figures, but it will be appreciated that any of the PRV, FCPRC or connector embodiments described herein can be used with a valve body having those features.

[0363] Figure 20 The diagram illustrates a tuning method for FCPRV 100. At step 160, system 10 undergoes a pressure test to determine the system flow (e.g., the flow delivered to the patient) versus total pressure drop response curve for system 10. In step 161, the desired release pressure is determined by comparing the flow curve with the system pressure, for example, by adding an offset pressure to the system pressure versus the flow curve. At step 162, the FCPRV is installed in system 10. At step 163, a flow restriction is then gradually added downstream of the FCPRV 100, and the resulting release pressure for a series of flows is determined to produce a measured pressure relief versus flow curve. At step 164, the actual pressure relief versus flow curve is compared with the desired curve. At step 165, if the actual curve does not match the desired curve, the size of the flow restriction (Venturi throat or orifice) is adjusted, and steps 163 and 164 are repeated until the desired pressure relief characteristics are achieved, at which point the FCPRV 100 has been successfully tuned at step 166.

[0364] Alternatively or additionally, the discharge pressure threshold can be adjusted by adjusting any or more of the other characteristics of the PRV. For example, the tension in the valve diaphragm 105 can be adjusted, for example, by adjusting the relative position of the valve inlet 101 to the valve member 105 or the size of the discharge outlet 103. In the PRV 100, the size of the discharge outlet determines the shape of the pressure relief valve's pressure-to-flow profile and thus the discharge pressure threshold over a range of flow rates. When the system is completely blocked / clogged, the FCPRV operates as the PRV described previously, except that the sensing element can provide some additional bias to the valve member 105. Moreover, the bias force provided by the sensing element 155 to the valve member 105 can be adjustable. For example, the length of the mechanical link 157 between the sensing element and the valve member can be adjustable; a shorter link increases the bias force and thus the discharge pressure.

[0365] Figure 2 and 3 An embodiment of an FCPRV 100 is shown, having a connector 200 for coupling the FCPRV to a conduit for supplying gas to a patient. Figure 2The embodiment of the connector 200 shown in FIG. 1 is a single piece. The connector 200 is a male connector. The connector 200 is configured for use with a second connector, which is a female connector provided by the FCPRV. An example of the female connector is the valve body 110 at the outlet 205, as shown in FIGS. 1 Figure 1C and 2 Other examples of the second connector are described later in this specification.

[0366] Referring to Figure 2 and 3 Features of one embodiment of the connector 200 will now be described. The connector 200 has a connector body with an inlet 203 and an outlet 205. The inlet 203 and the outlet 205 define a gas flow passage therebetween. In some embodiments, the gas flow passage is or includes a pressure line. The gas flow passage is at least partially defined by a wall 207 of the connector 200. The wall 207 provides the connector as a tubular member with a generally cylindrical shape that can taper and / or vary in cross-sectional area along the length of the connector 200. In other embodiments, the connector 200 includes other cross-sectional shapes, such as oval, ovoid, oblong, square, and rectangular.

[0367] The connector body has an overlap portion that is configured to overlap with a portion of the second connector when connected 201. The connector 200 has an access passage, access orifice, or access hole that extends through the overlap portion 201 to the gas flow passage. The access passage is in fluid communication with the gas flow passage of the connector to enable sensing of the pressure in the gas flow passage. In this embodiment, the access passage includes an orifice 211. In other embodiments, the access passage includes a hole. Figure 2 and 3In the embodiment shown, the orifice extends through the wall 207 of the connector 200. This embodiment has a single orifice 211. The orifice 211 has a size and shape similar to that of the spill line 111. In alternative embodiments, there can be more than one orifice 211 extending through the wall 207. The connector 200 can have alignment features (not shown) to guide the connector toward the correct alignment position to ensure that the orifice 211 is aligned with the spill line 111. Examples of alignment features include two-dimensional features such as text, symbols, and arrows. Other examples of alignment features include three-dimensional features such as complementary protrusions and recesses. In various embodiments, the connector 200 can have one or more alignment positions relative to the main outlet 153 of the FCPRV 100 to facilitate obtaining or not obtaining flow and / or pressure compensated response from the valve 100 and / or not obtaining any pressure relief from the valve 100. In a first configuration, the orifice 211 is not aligned with the spill line 111 of the sensing mechanism, and thus there is no fluid communication between the gas flow passage through the connector 200 via the entry passage 211 and the sensing chamber 154, such that the valve 100 does not provide any pressure relief functionality, but still allows gas to flow through the flow passage between the main inlet 151 and the main outlet 153. In this configuration, the valve does not function as a pressure relief valve. In a second configuration, the orifice 211 is aligned with the spill line 111, such that there is fluid communication between the gas flow passage through the connector 200 via the spill line 111 of the sensing mechanism and the entry passage 211 and the sensing chamber 154. The FCPRV 100 thereby functions as a flow and / or pressure compensated pressure relief valve as described above.

[0368] The exterior features of the connector 200 are preferably sealed against the interior features of the second connector (e.g., the main outlet 153 of the valve body 110). In this embodiment, a portion of the outer surface of the connector 200 is tapered. This surface is tapered inwardly toward the terminal end (inlet 203) of the connector 200. The taper is preferably a constant taper. The connector body tapers outwardly from the terminal end, from a smaller diameter to a larger diameter. In other embodiments, the connector 200 can have a constant diameter.

[0369] The main outlet 153 of the valve body 110 has complementary size and taper such that the components are preferably sealed when assembled. Further embodiments are described below in which the connection between the main outlet 153 and the connector creates the effect of a low pass filter between the flow passage through the connector and the sensing mechanism. In this embodiment, there is no low pass filter effect because the walls of the main outlet 153 and the connector 200 do not form a cavity in which the gas flow passage and the spill line 111 are in fluid communication.

[0370] The connector 200 can include a stop. In the illustrated embodiment, the stop is a shoulder 209. The shoulder 209 is integral with the connector body. The shoulder 209 is positioned to abut the termination of the FCPRV outlet 153 / second connector when the connector 200 is assembled with the FCPRV body, thereby preventing or at least substantially inhibiting over-insertion of the connector 200 into the second connector.

[0371] The connector 200 can further include an engagement mechanism configured to couple the connector to the FCPRV 100. In the illustrated embodiment, the engagement mechanism is a shoulder 209. The shoulder 209 is integral with the connector body. The shoulder 209 is positioned to abut the termination of the FCPRV outlet 153 / second connector when the connector 200 is assembled with the FCPRV body, thereby preventing or at least substantially inhibiting over-insertion of the connector 200 into the second connector. Figure 2 3 In the illustrated embodiment, the cooperation between the connector 200 and the main outlet 153 of the valve body 110 acts as the engagement mechanism. That is, the connector 200 is held in place due to the frictional forces between the inner wall of the second connector / main outlet 153 and the outer surface of the connector 200.

[0372] Another (second) embodiment of the connector will now be described with reference to Figure 4 5 The connector 400 has the same features and functionality of the first connector 200, unless described below. Like numbers are used to indicate like parts with the first connector 200.

[0373] In this embodiment, the connector has a cavity-forming portion 413 and a sealing mechanism 415. The sealing mechanism 415 substantially pneumatically seals the connector 400 and the main outlet 153 of the valve body 110 when the connector 400 and the valve 100 are assembled. The cavity-forming portion 41 and the main outlet 153 of the valve body 110 form a cavity.

[0374] The cavity-forming portion 413 is a recess or variation in the surface of the connector body facing away from the gas flow path. The outer surface of the cavity-forming portion has a shape that is not complementary to the inner surface of the main outlet 153 of the FCPRV 100, such that when assembled, the surface can be configured (e.g. have converging, diverging and / or parallel portions) to form a cavity 414. In this embodiment, the recess is provided by a stepped portion of the connector outer surface, while the main outlet 153 of the valve body 110 does not have a complementary shape. Rather, the main outlet 153 of the valve body 110 has a gradual taper, such that when assembled, the connector 400 and the main outlet 153 define a cavity 414 therebetween. In other configurations, the main outlet 153 of the valve body 110 can be free of taper. The cavity 414 is defined by the inner surface of the main outlet 153 of the valve body 110 and the cavity-forming portion 413 when the connector 400 is coupled to the main outlet 153. In addition to having a stepped portion, the cavity-forming portion 413 comprises an arcuate (including but not limited to arc-shaped) surface, preferably a radial surface. The arcuate surface is defined by a cylindrical connector body.

[0375] ​​When formed, cavity 414 is in fluid communication with overflow line 111. The formed cavity 414 is in fluid communication with airflow channel via inlet channel 411. Inlet channel includes one or more orifices 411. This arrangement allows pressure in airflow channel to communicate through orifices 411 into cavity 414 and then into overflow line 111 and second chamber 154b, which enables the generation of a pressure differential across sensing element 155 in sensing chamber 154, allowing FCPRV 100 to function as described above.

[0376] In the illustrated embodiment, the cavity forming portion 413 has a longitudinal dimension along a longitudinal axis that is substantially parallel to the airflow direction in the airflow channel. In an alternative embodiment, the cavity forming portion 413 may not be substantially parallel to the airflow direction in the airflow channel. In this embodiment, one or more orifices 411 are arranged substantially parallel to or substantially perpendicular to the airflow direction in the airflow channel. The position and formation of the cavity 414 relative to the overflow conduit 111 or the opening of the overflow conduit 111 can be varied, assuming it is in fluid communication with the overflow conduit 111 via the orifice 411.

[0377] In this embodiment, orifices 411 are arranged on a stepped portion / shoulder 412 formed between the cavity forming portion 413 and the sealing portion 415. This embodiment includes three orifices 411 arranged radially around the airflow passage. More orifices 411 may be present, for example, four or five orifices 411. Fewer orifices 411 may be present, for example, one or two orifices.

[0378] At least one orifice 411 may be in fluid communication with an airflow channel via another orifice, which is connected and in fluid communication via a groove (e.g., a port in the wall of a connector that allows downstream sampling).

[0379] Figure 4 and 5 The connector's inlet end (terminal) is shown to include a wall 404 with an inlet orifice 403, which provides flow restriction or additional flow restriction. The inlet orifice 403 is also the inlet of the connector 400. The wall 404 is spaced inwardly from the end of the connector, forming a recess. The wall 404 is positioned slightly inwardly and spaced from the terminal, which increases the rigidity of the terminal. The inlet orifice 403 is a tuning orifice that engages with a radial clearance, as described below. In an alternative embodiment, the wall 404 and the inlet orifice 403 may be arranged directly at the terminal of the connector 400. In another alternative embodiment, the orifice 403 may not be present; that is, the wall 404 is a continuous wall. In this embodiment, all gas flows through the inlet channel orifice 411.

[0380] The sealing mechanism 415 is configured to form a first seal with a portion of the main outlet 153 of the valve body 110. The sealing mechanism can include one or more of the sealing mechanisms known in the art, such as a face seal, O-ring, lip seal, dust seal, or sealing surface. In Figure 4 and 5 In the embodiment shown in

[0381] The cavity 414 is upstream of the sealing mechanism. In this case, the seal includes an outer seal, i.e., a seal adjacent to the terminal end of the main outlet 153 and / or the collar 409 of the connector adjacent to Figure 4 for the valve to function. Figure 4 An example of an embodiment with this outer seal is shown as a sealing surface, where the outer seal is formed by the engagement or interaction of a portion of the outer wall of the connector 400 with a portion of the inner wall of the main outlet 153. It should be noted that other embodiments described as having one seal can also be implemented with a single sealing surface. The outer seal can be defined as the seal downstream of the overflow line 111 and the cavity 414 formed.

[0382] By providing a PRV body 110 and a separate connector 400, it is possible for the characteristics of the PRV body to be set or fixed, while the pressure relief characteristics can be easily tuned by changing and / or adjusting the characteristics of the connector or changing the connector used. Instead of providing a large number of different FCPRVs, it is possible to provide one design of PRV body and a number of different connectors. Each connector can be specifically tuned to provide the desired characteristics, functionality, and / or pressure relief characteristics, such as sealed and unsealed breathing systems and different sizes of patient interfaces, such as nasal cannula. For example, at step 165 of the tuning process illustrated in Figure 20 the size of the flow restriction can be adjusted by changing the connector to one with a different size of inlet 403.

[0383] As shown in Figure 6 In some embodiments, an additional inner seal 619 can be present. The inner seal 619 includes a seal upstream of the overflow line 111 and a cavity 614 formed as described further below. This inner seal can be adjacent to the center of the pressure relief valve when the connector 600 is engaged with the main outlet 153.

[0384] In alternative embodiments, other configurations of the connector and valve body 110 can be used to form the cavity 414, 614. For example, the main outlet 153 of the valve body 110 can have a stepped portion and the connector can have a tapered taper. In another alternative embodiment, the main outlet 153 of the valve can have a taper and the connector can have a different taper. In another alternative embodiment, the main outlet 153 of the valve body 110 can have a stepped portion variation and the connector 400 can have a stepped portion variation, where the stepped portion variation is offset in a direction parallel to the direction of air flow, forming a cavity. Additionally, the shape of the connector 400 and the shape of the main outlet 153 of the valve body 110 or other piece of the valve and the configuration of those components can be selected or designed, when assembled, such that there are tolerances and the components do not have to be precisely aligned to form a suitable cavity.

[0385] In Figure 4 and 5 embodiment 400, the radial gap occurs at high fluid velocities. The flow accelerates through the orifice 411 and creates a low pressure area. In this embodiment, there is a resulting annular cavity 414 that is sealed at only one end (the outer seal). The size of the annular cavity 414 between the connector 400 and the inner wall of the main outlet 153 of the valve body 110 would have to be considered in the absence of a seal, such that the bleed off occurs as desired. Since the cavity is sealed at only one end, while the other end is in fluid communication with the air flow passage, this can make tuning of the valve more difficult. The valve tuning must take into account the leakage flow into the cavity 414 that can affect the pressure differential across the sensing member 155 in the sensing chamber 154. Tuning the valve involves adjusting the size of the tuning orifice 403 or changing the diameter of the main outlet 153 and / or the cavity forming portion 413 to change the size of the radial gap to achieve the desired response. Changing the radial gap will adjust the flow rate. The relative sizes of the orifice 403 and the radial gap will change the ratio of flow taking each path. This can be accomplished by replacing the different connectors with different sized inlet orifice 403, outlet 153, and / or cavity forming portion 413.

[0386] The connector can include a stop. In the illustrated embodiment, the stop is the collar 409. In the illustrated embodiment, the collar 409 is an annular collar. In alternative embodiments, the stop can be another feature that includes the collar 409. The collar 409 is integral with the connector body. In alternative embodiments, the collar 409 can be a separate component that is assembled with the connector body. The surface of the collar 409 can be configured to form a face seal with a surface of a second connector. In other configurations, the collar 409 can replace or assist the sealing mechanism 415. The collar 409 prevents or at least substantially prevents the connector 400 from being over-inserted into a second connector.

[0387] Reference will now be made toFigure 6 and 7 Another (third) embodiment of a connector is described. The connector 600 has the same features and functionality of the second connector 400, unless described below. Like numbers are used to indicate like parts with the addition of 200.

[0388] In this embodiment, there is a first sealing mechanism 615 and a second sealing mechanism 619. Embodiments of connectors with two sealing mechanisms facilitate tuning of the responsiveness of the CPRV. The cavity forming portion 613 is between the first sealing mechanism 615 and the second sealing mechanism 619. The access channel is in fluid communication with the cavity 614. The access channel is also positioned between the first sealing mechanism 613 and the second sealing mechanism 615. In Figure 6 and 7 In the embodiment of FIGS. 11-13, the cavity 614 formed between the first sealing mechanism 615 and the second sealing mechanism 619 when the connector 600 is coupled to the main outlet 153 is an annular cavity. This is because the main outlet 153 of the valve body 110 has a radial bore and the connector 600 has a radial outer surface.

[0389] In the embodiment shown in Figure 6 and 7 In the embodiment shown in FIGS. 11-13, the second sealing mechanism 619 is a sealing surface. The first sealing mechanism 615 and the second sealing mechanism 619 are formed by an interference / friction fit of the outer surface of the connector 600 as shown and the complementary inner surface(s) of the main outlet 153 of the valve body 110. However, many other methods can be used to create the seals and form the cavity. For example, O-rings, dust seals, adhesives, foam, or lip seals can be used at different locations on the connector and seal with the inner or outer surface of the female connector (valve body 110) to form the cavity 614. Additionally, an internal interference fit can mate with retaining features such as lugs and clips on the outside of the valve / connector assembly or other external sealing methods are used for one seal to create the cavity.

[0390] Figure 15 A simplified schematic cross-section of a connection assembly is shown in which two O-ring seals of different sizes are used as alternative sealing mechanisms to form a cavity 1114. Figure 15 A first sealing mechanism in the form of a relatively small O-ring 1115 is shown. Figure 15 A second sealing mechanism in the form of a relatively large O-ring 1119 is also shown. The cavity 1114 is formed between the O-rings 1115, 1119. Depending on the size and shape of the connector and body, the O-rings 1115, 1119 can be closer in size, the same size, or the O-ring of the first sealing mechanism 1115 can be larger than the O-ring of the second sealing mechanism 1119. Figure 15The embodiment in FIG. 11 shows an opening, access port, or access channel 1111 in the overlap portion in communication with the pressure line 111 via a cavity 1114.

[0391] Returning to Figure 6 to 8 which shows a preferred connection assembly, in the embodiment shown, the overlap portion 601 includes a first sealing mechanism 615. The overlap portion 601 also contains a second sealing mechanism 619. In alternative embodiments, the overlap portion 601 can contain only one of the sealing mechanisms.

[0392] Figure 8 The main outlet 153 of the valve body 110 is shown with a tapered bore. The bore of the main outlet 153 of the valve body 110 has a non-standard diameter. This is to avoid connection of an incorrect connector with the main outlet 153. In this embodiment, the flow restriction is provided by the orifice 603 at the inlet to the connector (rather than by the valve body). If an incorrect connector is made to fit within the main outlet 153, the valve is unlikely to operate as a flow and / or pressure compensated valve or provide a pressure relief valve, as the valve and connector will not have a flow restriction and / or an access channel to the main gas flow path that enables flow and / or pressure sensing as described with respect to embodiments of the valve and connector. In this case, if an incorrect connector that does not provide fluid communication between the second sensing chamber and the main gas flow path between the main inlet 151 and the main outlet 153 (e.g. via the communication line 111) is used with the FCPRV body, the pressure response of the valve 100 will match the response observed when the outlet 153 of the valve 153 is plugged and gas is being expelled from the valve. This can include a substantially flat response of, for example, 20 cm H20. If an incorrect connector that does not provide fluid communication between the second sensing chamber and the main gas flow path between the main inlet 151 and the main outlet 153 (i.e. the communication line 111 is plugged) is used with the FCPRV body, the valve 100 will not provide any pressure relief during use, but gas can still flow through the main flow path. Thus, the respiratory system can not be able to deliver all of the prescribed flow to the patient or the flow is restricted.

[0393] It is preferred that the connector and the main outlet 153 of the valve body 110 are pneumatically sealed such that there is no significant leakage of gas to atmosphere. In some embodiments, if there is a known or expected leak, the flow restriction can be adjusted based on the known or expected leak (e.g. by changing the size of the tuning bore) such that the expected valve function is maintained.

[0394] Figure 9 to 11 Some alternative connection assemblies are shown. In Figure 9In this case, pressure sensing is provided by upstream and downstream pressure lines 113, 111. Both the downstream (first) pressure line 111 and the upstream (second) pressure line 113 are coupled to a pressure sensing mechanism, such as a sensing diaphragm of a flow and / or pressure compensated relief valve, a differential pressure sensor, or multiple absolute or gage pressure sensors. The pressure sensing mechanism can be a sensing mechanism 150 that the first pressure line 111 is in fluid communication with the second chamber 154b and the second pressure line 113 is in fluid communication with the first chamber 154a. In various embodiments, the pressure sensing mechanism can be a pressure sensing mechanism that simply samples the pressure upstream and downstream of the flow restriction defined by the orifice 603.

[0395] Figure 10 and 11 Another alternative assembly is shown in which the second connector is not formed by the FCPRV outlet but is another connector for attaching the connection assembly to another circuit component, such as a manifold. Upstream and downstream pressure lines 117, 115 are provided through the wall of the second connector. The second connector can include an engagement mechanism configured to engage the second connector with the circuit component. Figure 10 An engagement mechanism including a groove 120 is shown. The groove can engage a seal, such as an O-ring. The end 119 of the second connector can be received by the circuit component such that the O-ring seals against an inner surface of the circuit component. Alternatively, the groove 120 can act as a snap-fit type engagement mechanism whereby a protrusion provided in the circuit component snaps into the groove 120.

[0396] The engagement mechanism can also take other common forms, such as an interference fit, a twist / tighten attachment, or a snap fit. Reference is made to Figure 9 and 10 In the embodiment of 613, the chamber forming portion tapers relative to the direction of gas flow. In addition, Figure 9 and 10 A connector is shown that tapers from the terminal end, tapering from a larger diameter to a smaller diameter.

[0397] Figure 13 Another alternative embodiment of a connector 800 is shown that is used to sample the pressure downstream. The connector 800 has the same features and functionality of the third embodiment connector 600, unless described below. Like numbers are used to indicate like parts with the addition of 200.

[0398] Figure 13The embodiment shown illustrates a connector 800 having an opening or orifice 811a in an overlap portion 801, the opening or orifice 811a communicating via a pressure channel or conduit 812 within the wall of the connector 800 to another orifice 811b in the wall of the connector 800 leading to the main airflow path. The pressure channel or conduit 812 connects a cavity 814 at the overlap portion 801 to the main airflow path at a portion of the connector (or another loop component) downstream of the main outlet 153. Compared to the previously described embodiment, the pressure sampling orifice is a pressure sampling conduit defined by orifices 811a, 811b and the pressure channel 812, wherein orifice 811b is provided further downstream. If desired, the location of the pressure sampling orifice 811b (which may be located outside the terminal of the main outlet 153) and the pressure conduit 812 allows the flow restriction formed by the wall 804 and orifice 803 to be moved further downstream, as in... Figure 13 As shown in the diagram. If it is desired that the location 811 for flow restriction and / or pressure sampling be moved, pressure is sampled downstream of the flow restriction. Figure 13 The embodiments shown illustrate pressure sampling lines that can be sampled even further downstream. This provides greater flexibility in terms of the location of flow restrictions.

[0399] Figure 14 A connector 1000 with regions having different diameters is shown. Connector 1000 has the same features and functionality as connector 800 of the fourth embodiment, unless described below. Similar numbers are used to indicate similar parts having a sum of 200.

[0400] Figure 14 The embodiment shown illustrates a connector 1000 having a pressure channel or conduit 1012 within the wall of the connector 1000. The pressure channel or conduit 1012 may be substantially rigid or may comprise a flexible conduit. Downstream of the main outlet 153, the pressure channel or conduit 1012 fluidly connects the cavity 1014 at the overlapping portion 1001 to a main airflow path at a portion of the connector (or another loop component). Similar to the fourth embodiment, a pressure sampling orifice is a pressure sampling conduit partially defined by the pressure channel 1012. An orifice (similar to orifice 811b) is provided further downstream and is not shown because it is located further downstream than... Figure 14 The features shown are further downstream. This orifice is much further downstream than the orifice in the fourth embodiment. If needed, the location of the pressure sampling orifice and pressure line 1012 allows the flow restrictions formed by the wall and orifice to be moved further downstream. Furthermore, they are not in... Figure 14 As shown in the diagram, because they are more than Figure 14The features shown in FIG. 12 are more downstream. Similar to the fourth embodiment, the flow and / or pressure of the gas flow through the gas flow passage can be sampled downstream of the flow restriction 1203. By providing a pressure sampling line that can sample more downstream than the previous embodiments, the connector provides more flexibility in terms of where the flow restriction is located.

[0401] The area closest to the inlet 1203 has a smaller diameter than the area closest to the outlet 1205. The difference in diameter causes the aforementioned internal taper of the FCPRV body that forms the cavity 1214.

[0402] Orifices (not visible) exhaust flow into the cavity 1214 and then into the diaphragm chamber. The orifices are positioned tangent to the vertical surface where the change in diameter occurs. That is, the orifices are positioned near the direction of flow. Additionally or alternatively, the orifices can be positioned outwardly or at other locations on the connector, provided they allow exhaust into the cavity 1214 formed. Similar to the previous embodiments, the connector has a pressure line 1212 within the wall of the connector 1200.

[0403] Figure 16 Another alternative embodiment of a connector 1400 that can be used is shown. The connector 1400 has the same features and functionality of the third embodiment connector 600, unless described below. Like numbers are used to indicate like parts with the addition of 800.

[0404] Figure 16 The connector shown in FIG. 14 provides a cavity 1414 that is in fluid communication with the overflow line 111. The connector has one or more orifices 1411 in fluid communication with the gas flow passage. Figure 16 The embodiment shown in FIG. 14 has a connector that provides a venturi shape that restricts flow 1404. The orifices 1411 and the flow restriction 1404 are substantially aligned, so pressure is sampled at a point of high flow rate. The annular cavity 1414 acts as a low pass filter. The low pass filter provides a damping effect. This low pass filter reduces turbulence in the flow and increases the stability of the flow because the volume of the chamber is pressurized before the volume of the diaphragm is pressurized. The size of the cavity formed will affect this low pass filter, but the orientation of the orifices will not.

[0405] Figure 17 Another alternative embodiment of a connector 1400 that can be used is shown. The connector 1400 has the same features and functionality of the third embodiment connector 600, unless described below. Like numbers are used to indicate like parts with the addition of 800.

[0406] Figure 17The connector shown in FIG. 14 provides a cavity 1414 in fluid communication with the overflow line 111. The connector has one or more orifices 1411 in fluid communication with the gas flow path. Figure 17 The outer portion of the embodiment shown in FIG. 14 has multiple stepped portions, or changes in diameter. Similar to the connector of FIG. 13, Figure 16 the annular cavity 1414 acts as a low pass filter.

[0407] Figure 18 An alternative form of the connection assembly is shown, where the connector 1600 comprises at least two parts, a first part 1600A and a second part 1600B. The connector 1600 has the same features and functionality of the third embodiment connector 600, unless described below. Like numbers are used to indicate like parts with an addition of 1000. The two parts 1600A and 1600B are separated by a gap. In this embodiment, the first part comprises a wall 1604 providing a flow restriction and an orifice 1603. The interior of both parts 1600A and 1600B are in fluid communication with the overflow line 111. The first part 1600A with the flow restriction 1604 also has a sealing mechanism 1619 having the same features and functionality of the second sealing mechanism of the third embodiment connector 600. The second part 1600B also has a sealing mechanism 1615 having the same features and functionality of the first sealing mechanism of the third embodiment connector 600. Optionally, the two parts 1600A and 1600B can be connected by a cable or tether or other mechanism, so that the two parts can be easily removed if needed. In some embodiments, the first part 1600A can be permanently connected, or configured to be permanently connected, to the valve body 110 or the main outlet 153, for example as a multi-use part that is reused multiple times. The second part 1600B can be removable, for example as a single-use part. The first part 1600A can have any form that creates a pressure drop. For example, the first part 1600A can be or comprise a permeable material (such as foam, porex, membrane, etc.) with or without orifices, or an insert with one or more orifices.

[0408] In some applications, the valve 100 itself can create a portion of the pressure drop, with the connector 1600 providing an additional portion of the pressure drop. In addition to the small pressure drop when fluid flows from the main inlet through the valve 100, there can also be two main regions each with a substantially segmented pressure drop when the connector is connected. An example of a feature that creates a pressure drop is the relatively large hole 1630 shown in FIG. 16. Figure 18 For example, in Figure 2 , 4Other forms or variations of the valve, having an orifice within the valve that creates a pressure drop, are shown in Figures 6, 8, 13, 14, 18, and 19. Preferably, the majority of the pressure drop through the valve and connector assembly is provided through the orifice 403, 603, etc. provided by the connector.

[0409] Another embodiment of a connector will now be described with reference to Figure 19 Another embodiment of a connector will now be described with reference to

[0410] In this embodiment, the second sealing mechanism 1819 is a female seal. That is, in contrast to the third embodiment of the connector 600, in which the sealing surface faces in a direction away from the airflow passage, the seal is provided by a wall or surface of the connector 1800 that faces towards the airflow passage.

[0411] In the embodiment shown in Figure 19 In the embodiment shown in

[0412] Another embodiment of a connector will now be described with reference to Figure 21 Another embodiment of a connector will now be described with reference to

[0413] In the connector 700 Figure 21 In the connector 700

[0414] The orifice 1211, 1411, 711 provided in the wall of the connector 1200, 1400, 700 for sensing pressure is preferably provided in a region of laminar or low turbulent flow. For example, the orifice can be provided in the wall of the connector at, or immediately adjacent to and downstream of, a flow restriction.

[0415] Figure 16An exemplary connector 1200 is shown having a flow restriction 1204 of the venturi type, wherein the sensing orifice 1211 is provided at the narrowest point of the venturi. Figure 47 and 48 An alternative embodiment connector 2800 is shown (assembled with the FCPRV 100 described above), wherein the sensing orifice 2811 is also provided at the flow restriction 2804. In this embodiment, the flow restriction 2804 is a restriction of the orifice plate type, wherein the one or more sampling orifices 2811 are provided by one or more grooves in the wall of the orifice plate, in fluid communication with the orifice 2804.

[0416] Alternatively, the one or more sampling orifices can be provided in close proximity to the flow restriction, preferably on the downstream side of the flow restriction. Figure 45 and 46 An alternative embodiment connector 2700 is illustrated, wherein the sampling orifice 2711 is provided in the shoulder of the connector 2700, immediately downstream and in close proximity to the flow restriction 2704. It is advantageous to provide the sampling orifice as close as possible to the flow restriction, as the gas flow at these points is more likely to be laminar or have low turbulence as compared to the flow at points further downstream of the flow restriction.

[0417] The connectors 2700 and 2800 have similar features and functionality as the third embodiment connector 600, unless otherwise described. Like numbers are used to indicate like parts with the connectors 1100 or 1200, respectively.

[0418] To facilitate manufacture of the connector, a molded notch 721 can be present at the upstream inlet end of the connector 700, for example by injection molding.

[0419] In some embodiments described herein, the connector is provided as a male member, and the outlet port of the valve is provided as a female member, wherein the connector is received by the outlet port to form the gas flow passage. In other embodiments and / or configurations, the connector can be provided as a female member, and the outlet port of the valve can be provided as a male member, wherein the outlet port is received by the connector to form the gas flow passage. Also in other embodiments and / or configurations, the connector can contain male and / or female parts that correspond to, engage and / or couple complementary female / male parts of the outlet port of the valve, for example as shown in Figure 19 .

[0420] In some embodiments described herein, the lumen-forming portion can be tapered with respect to the gas flow direction. An example is when the gas flow passage is or contains a pressure line. The connector can taper towards the terminal end, from a larger diameter to a smaller diameter.

[0421] In some embodiments, the connector may be configured to be coupled to a pressure relief valve. Specifically, the connector may further include an engagement mechanism configured to couple the connector to the pressure relief valve. Suitable engagement mechanisms include clips, complementary threaded portions, or press-fits. In the illustrated embodiment, the engagement mechanism is a press-fit.

[0422] In some embodiments, the pressure relief valve may be a flow-compensated and / or pressure-compensated pressure relief valve. In some embodiments, the pressure relief valve may be a flow-compensated pressure relief valve or a pressure-compensated pressure relief valve. A pressure line may be in fluid communication with the sensing chamber of the pressure relief valve. The pressure relief valve may include a sensing element configured to sense the pressure difference between the sensing chamber and a main airflow passage supplying airflow to the patient. Movement of the sensing element alters the discharge pressure of the valve component.

[0423] In some embodiments, the pressure line is a first pressure line, and the connector further includes a second pressure line upstream of the first pressure line. Both the first and second pressure lines can be coupled to the pressure sensing mechanism.

[0424] In some embodiments, the connector may be configured to be coupled to a breathing circuit component. For example, the connector may include an engagement mechanism configured to engage the connector with the breathing circuit component. Suitable engagement mechanisms include clips, complementary threaded portions, or press-fits.

[0425] Some described embodiments indicate the flow direction. However, in all described component embodiments, the airflow direction can be either direction. The terms 'upstream' and 'downstream' as used herein depend on the flow direction, for example, within an airflow channel.

[0426] Any of the connectors described herein can be releasably or permanently secured to the end of a pipe, or integrated with the end of a pipe. Figure 6 An example of pipe 900 is shown. Connectors can be assembled with the pipe during or after manufacturing. The pipe can be any suitable pipe. The pipe will be selected or designed based on a number of factors. Those factors include the location of the pressure relief valve in the circuit, and / or the location where pressure sensing is desired.

[0427] The connector can be configured to releasably attach to the end of an existing pipe, enabling the existing pipe to be used with the pressure relief device described herein. The connection between pipe 900 and connector 400 can be via an interference fit, for example, where the pipe connection portion 417 of the connector is received by pipe 900 and seals against the inner wall surface of the pipe. Alternatively, the connection portion 405 of the connector can receive pipe and form an interference fit with the outer surface of the pipe.

[0428] The conduit with the connector 100 is then connected to the PRV body, forming a connection assembly. In a preferred embodiment, the connector is attached to the end of the conduit during manufacturing. The connector and conduit are then connected to the PRV by the user. The conduit can be part of a circuit between a flow source and a humidifier or between a pressure relief valve and a humidifier. For example, the conduit can extend from the flow source to the humidifier. The conduit can be referred to as a dry line when it connects the outlet of the flow source or pressure relief valve to the inlet of the humidifier or humidification chamber and it carries gas that is not humidified. In addition, additional components can be included to alter the circuit (e.g., a flow modulator), and the dry line can extend from the flow source to one of these additional components or from the additional component to the humidifier or humidification chamber. In some embodiments, the flow modulator receives the flow of gas from the flow source, and the connector and conduit are connected to the outlet of the flow modulator to deliver the flow of gas from the flow modulator to the humidifier or humidification chamber so that the flow of gas is humidified. The flow modulator can be a flow modulator having the features described in WO / 2017 / 187390, the entire contents of which are incorporated herein by reference.

[0429] In preferred embodiments, the interaction between the connector integral with or coupled to the dry line and the valve is an interference / friction fit. However, other methods can be employed, such as twist / tighten attachment or external engagement mechanisms, such as adhesives (including but not limited to glues, chemical bonds, etc.), overmolding, and welding.

[0430] Each of the connectors described herein allow for easy changes or alterations to the tuning orifice by changing the connector rather than the entire valve. In addition, the described connectors prevent connection of an incorrect connector to the valve, as the valve will not function as expected unless the connector is a connector having the features and functionality of one of the embodiments described herein, or unless the connector is properly tuned for resistance to the desired flow of the circuit and patient interface (e.g., size of flow restriction).

[0431] Figure 24 Another embodiment, FCPRV 2000, is shown. FCPRV 2000 has similar features and functionality to FCPRV 100 of Figure 1C and 2 unless described below. Like numbers are used to indicate like parts having the addition 1900.

[0432] The FCPRV 2000 includes a device inlet 2051 and a device outlet 2053 with a main gas flow passage between the inlet and the outlet. A pressure relief mechanism is connected between the inlet and the outlet and includes a valve member in the form of a valve seat 2004 and a diaphragm member 2005, described in detail below. In some embodiments, the diaphragm member 2005 is a removable diaphragm member. A portion of the diaphragm member 2005 (e.g., a diaphragm and / or a linkage connector portion) is arranged to be seated against the valve seat 2004 in a first configuration and spaced apart from the valve seat in a second configuration when the gas flow passage exceeds a pressure threshold to provide pressure relief. In some embodiments, a base of the linkage connector portion can include a layer of overmolded diaphragm and the overmolded portion can be seated against the valve seat in the first configuration.

[0433] The FCPRV 2000 includes a sensing mechanism 2050 that dynamically adjusts the pressure threshold based on the flow rate of the gas flow at or through the outlet 2053. The sensing mechanism includes a sensing member in the form of a diaphragm member 2055 for permanent or releasable attachment to a valve adjustment member 2057. In some embodiments, the diaphragm member 2055 is a removable diaphragm member. In some embodiments, the diaphragm member 2055 is releasably attached to the valve adjustment member 2057. The valve adjustment member 2057 is operably coupled to the valve member and the sensing member of the pressure relief mechanism to change the relief pressure of the pressure relief mechanism.

[0434] Figure 24 The embodiment shown in the middle includes a coupler 2059 at the main inlet portion (which houses the main inlet 2051) for coupling a flow source to the device inlet 2051. The coupler includes a flange or lip 2060 that extends over the edge of the main inlet portion to prevent fluid or debris from entering the inlet 2051. In some embodiments, the coupler includes engagement features for engaging the inlet 2051 and / or the chamber cap 2012. In some embodiments, the coupler includes sealing features (e.g., O-rings) for sealingly engaging the inlet 2051 and / or the chamber cap 2012. In some embodiments, the coupler 2059 is coupled to the inlet 2051 via an interference fit.

[0435] In the embodiment shown, the coupler 2059 includes a sound attenuator. Additionally or alternatively, in some embodiments, the coupler can provide an adapter for connecting to different flow sources.

[0436] The chamber cap 2012 defines an orifice 2003 adjacent the device outlet 2053 through which air at atmospheric pressure can enter the valve chamber 2002 and through which gas released by the pressure relief mechanism can escape. The orifice 2003 can include a filter (not shown) that prevents dirt and contaminants from entering the device 2000 and reduces noise emitted by the valve during discharge. The filter includes a porous, air-permeable material.

[0437] In Figure 24 embodiments, both the valve member and the sensing member are provided by the diaphragm components 2005, 2055 illustrated in Figure 25 to 29B In this embodiment, the diaphragm component 2005 that includes the valve member is identical to the diaphragm component 2055 that includes the sensing member. However, in other embodiments of the FCPRV, the diaphragm components 2005 / 2055 for the valve and sensing members can be different.

[0438] The diaphragm components 2005 / 2055 include a flexible diaphragm 2023 / 2073 and a substantially rigid linkage connector portion 2025 / 2075. A portion of the diaphragm 2023 / 2073 is overmolded to the linkage connector portion 2025 / 2075 to bond the diaphragm to the linkage connector portion. The rigid linkage connector portion 2025 / 2075 is configured to be attached to a valve adjustment member, such as a mechanical linkage 2057.

[0439] The diaphragm components 2005 / 2055 further include a frame 2021 / 2071. The frame 2021 / 2071 is an annular and substantially rigid frame, although other shapes of the frame are possible. The substantially rigid frame 2021 / 2071 can be formed of any suitable rigid material, such as a metal, a plastic, or a composite material, for example, glass-filled polybutylene terephthalate (PBT), glass-filled nylon, polycarbonate, or other plastic materials known in the art. Each frame 2021 / 2071 rests and seals against a complementary rim provided on the FCPRV body 2010. The frame can include one or both of a joining feature and a positioning feature for attaching the frame to the FCPRV body 2010 and / or the chamber cap 2012. The joining feature enables attachment of the frame 2021, and thereby the diaphragm component 2005, to the body 2010 of the FCPRV 2000.

[0440] Referring to Figure 25 to 27which shows the valve member diaphragm component 2005, the engagement features include a plurality of clips 2026 that engage corresponding engagement features on the body of the FCPRV. In the illustrated embodiment, each clip 2026 includes an aperture or recess that receives a detent, catch, or protrusion provided on the body of the FCPRV. The clips 2026 protrude in a first direction from the frame 2021 and include a rectangular recess or aperture, although other shapes of clips and apertures are contemplated. The clips 2026 can have some flexibility such that they can flex and engage with the engagement features on the body, or the clips 2026 can be substantially rigid like the frame. Engagement of the clips 2026 of the frame 2021 to the valve body 2010 can produce an audible or tactile feedback that indicates that the engagement is complete. The engagement features on the body of the FCPRV can be provided by protrusions that extend outward from the rim 2013 on which the frame is seated.

[0441] The frame 2021 includes, in the illustrated embodiment, four engagement clips 2026 that are equally spaced around the perimeter of the frame. However, alternative embodiments can include more or fewer engagement features.

[0442] Figure 25 to 27 The frame 2021 further includes positioning features that correctly orient the diaphragm component 2005 when it is held or clipped to the valve body 2010. In the illustrated embodiment, the positioning features 2027 include a plurality of protrusions that protrude radially inward from the surface of the frame. The positioning protrusions abut the inner wall of the rim 2013 to help ensure that the diaphragm frame 2021 is concentric with the opening in the valve body 2010, by reducing any gaps between the two components.

[0443] In some embodiments, the body 2010 of the FCPRV can include complementary recesses that receive the positioning protrusions 2027. In such embodiments, the positioning protrusions 2027 on the frame 2021 can be irregularly spaced, i.e., the angular spacing between a pair of adjacent protrusions is different than the angular spacing between at least another pair of adjacent protrusions, such that there is only one angular orientation of the frame in which all of the positioning protrusions can engage with corresponding recesses in the FCPRV frame 2010.

[0444] When installed to the body of the FCPRV 2000, the linkage connector portion 2025 and / or the diaphragm 2023 of the valve member are aligned with the valve seat 2004 such that, in the first configuration of the pressure relief mechanism, the diaphragm and / or the linkage connector portion seal against the valve seat. Preferably, the engagement between the valve seat 2004 and the valve member 2005 is near the perimeter of the connector portion 2025, where the connector portion is overmolded and overlaps with a portion of the diaphragm 2023.

[0445] The frame 2021 / 2071 of each diaphragm member 2005 / 2055 contains a port 2022 / 2072. In the valve member, this port 2022 allows the valve chamber 2002 opposite the valve seat 2004 to communicate with the atmosphere (the environment outside the FCPRV). The port 2022 is sized to receive a rigid cylindrical tube provided on the body and defining a passageway for communication between the valve chamber 2002 and the atmosphere. In the sensing member, the port 2072 in the frame 2071 of the diaphragm member 2055( Figure 29A and 29B ) allows the second sensing chamber 2054b to communicate with the pressure tapping or communication line 2011 so as to sense the flow rate and / or pressure of the gas flow at or through the outlet 2053. The port 2072 is sized to receive a cylindrical tube defining the pressure tapping or communication line 2011.

[0446] The diaphragm 2023 / 2073 is a flexible member received within the space defined by the annular frame, with a peripheral portion of the diaphragm overmolded to the frame. The rigid frame 2021 / 2071 can be a insert molded with the diaphragm 2023 / 2073, with a portion of the diaphragm 2023 / 2073 overmolded to the frame 2010. The diaphragm 2023 / 2073 preferably contains an elastomeric material, such as a thermoplastic elastomer (TPE), LSR (liquid silicone rubber), and molded rubber.

[0447] The linkage connector portion 2025 / 2075 is a substantially rigid member positioned centrally with respect to and concentric with the diaphragm frame 2021 / 2071. The connector portion 2025 / 2075 can be formed of any suitable rigid material, such as a metal or a plastic material, such as polycarbonate or other plastics known in the art.

[0448] The connector portion 2025 / 2075 is adapted to be removably coupled to a valve adjustment member, such as the mechanical linkage 2057 described herein. Engagement features are provided on the connector portion 2025 to forcibly engage with end portions of the mechanical linkage 2057.

[0449] In the illustrated embodiment, the engagement features contain four engagement fingers 2028 extending from the center of the connector portion 2025 in a first direction, although other engagement features, such as other fasteners, are possible. The engagement features can contain more or less than four engagement fingers 2028. Each engagement finger 2027 contains a protrusion 2029( Figure 27 ) near the free end of the finger, which protrudes in an inward direction toward the central axis of the diaphragm 2005.

[0450] A boss 2033 extends along a first direction from the center of the connector portion 2025 between the engaging fingers. The boss extends only a portion of the length of the fingers and is provided for ease of manufacture. The boss 2033 supports the end of the mechanical link 2057, while the depth of the boss allows for additional length of the engaging fingers 2028 for greater flexibility of the fingers.

[0451] The mechanical link 2057 includes at least one recess 2030, such as an annular recess adjacent to and spaced apart from each end of the mechanical link. A protrusion 2029 of each connector engagement finger 2028 forcibly engages the recess to secure the mechanical link to the connector portion. To engage the two components, the ends of the mechanical link 2057 are pressed into a space defined by four connector fingers 2078, where the protrusions contact the peripheral surface of the mechanical link. The connector engagement fingers 2078 flex as the mechanical link is pressed into place and move rearward to engage when the protrusions contact the recess.

[0452] In an alternative embodiment, the mechanical link may include one or more protrusions, such as annular protrusions, and the engagement features on the connector portion may include one or more recesses.

[0453] Figure 49 and 50 A valve member 2905 with an alternative embodiment connector portion 2925 is shown. Unless otherwise described, the valve member 2905 and the mechanical link 2957 have the same characteristics as in... Figure 27 The valve component 2005 and connecting rod 2057 shown have similar features and functionality. Similar numbers are used to indicate similar parts with a sum of 900.

[0454] The connector portion 2925 includes three engaging fingers 2928 extending from the center of the connector portion 2925 along a first direction; however, alternative embodiments may include more or fewer engaging fingers 2928. An inwardly projecting portion 2929 provided near the free end of each engaging finger 2928... Figure 27 In the embodiments, the protrusions 2029 on the engaging fingers are shaped differently. That is, each protrusion 2929 includes a substantially flat surface 2929a that is substantially perpendicular to the longitudinal axis of the mechanical link 2957. The engaging recesses 2930 provided at the respective ends of the mechanical link 2957 include complementary substantially flat surfaces 2930a for engaging the engaging fingers 2928, which are also substantially perpendicular to the longitudinal axis of the mechanical link 2957.

[0455] The flat surface 2929a on the engagement finger is provided on the portion of the corresponding protrusion 2929 distal of the top end of the engagement finger 2928. The portion of the protrusion 2929 distal of the top end of the engagement finger 2928 includes a sloped or arcuate surface relative to the mechanical link 2915.

[0456] The sloped or arcuate surface of the protrusion 2929 provides a lead-in and allows the finger 2928 to flex outwardly when the connector portion 2925 is pushed onto and engages the end of the mechanical link 2957. The vertical engagement surfaces 2929a, 2930a then engage and act to resist separation of the mechanical link 2957 from the connector portion 2925. This advantageously prevents accidental separation of the mechanical link 2957 from the connector portion during use, particularly when the device is subjected to high pressure such as in configurations when the device is not being used to provide pressure relief.

[0457] The sensing member 2955 can also include a connector portion (not shown) with the engagement features described above for engagement of the opposite end of the mechanical link 2957.

[0458] The link connector portion 2075 of the sensing member can be coupled to the mechanical link 2057 in the same manner as the valve member 2005 is coupled to the mechanical link but to the opposite end of the mechanical link 2057, thereby coupling the sensing member 2055 and the valve member 2005. When mated, the sensing connector portion 2075, the valve connector portion 2025 and the mechanical link 2057 are substantially coaxial.

[0459] The link connector portion 2025 / 2075 further includes a pair of spaced apart peripheral flanges 2031. The flanges 2031 are annular and coaxial, and each pair defines an annular space in the middle thereof to receive a respective diaphragm 2023 / 2073. The flanges 2031 define an annular space in the middle thereof to receive a respective diaphragm 2023 / 2073 during the overmolding process when the diaphragm is overmolded to the link connector portion 2025 / 2075.

[0460] The link connector portion 2025 / 2075 is preferably a insert that is molded with the diaphragm. During the overmolding process, a portion of the diaphragm fills the annular space defined by the annular flanges 2031 on the connector portion, forming a seal between the link connector portion and the respective diaphragm. This advantageously eliminates leakage between the connector portion and the respective diaphragm.

[0461] Preferably, the diaphragm is overmolded to both the connector portion and the frame in the same step to form a single, integral diaphragm component 2005 / 2055. This ensures that the connector portion 2025 / 2075 is centered relative to the frame and the diaphragm, thereby ensuring that the mechanical link 2057 is also centered.

[0462] In the FCPRV 2000, the damping of the valve response is provided primarily through three damping features that provide resistance to flow. The first damping feature includes an opening into the first sensing chamber 2054a through which a portion of the gas flow from the inlet 2051 to the outlet 2053 can pass into the first sensing chamber 2054a when in use. The second damping feature includes the communication tube 2011 that defines a passage between the second sensing chamber 2054b and the main gas flow passage through the outlet 2053. The third damping feature includes the port 2022 and the tube 2103 to which the port 2022 is joined to define a passage between the valve chamber 2002 and the atmosphere. These openings / passages / ports enable control of the level of damping of the flow and the valve response of the FCPRV. Controlling the level of damping can be achieved by varying the characteristics of these openings / passages / ports, such as their diameter or shape. Each of these three openings preferably has a constant diameter, so the damping effect is consistent and can be known. Alternatively, the openings can have a known tapering or otherwise varying diameter. These openings / passages / ports can include damping features that provide additional flow restriction, such as a filter. Figure 24

[0463] In the embodiment of the FCPRV 2000, the mechanical linkage 2057 includes a series of transverse ribs and is guided in the tubular guide 2007. The space between the mechanical linkage and the inner wall of the tubular guide is the entire passage for flow from the device inlet 2051 to the first sensing chamber 2054a. This restricted passage and turbulent flow path created by the ribs creates resistance to flow and has a damping effect on the flow onto the sensing mechanism 2050 by reducing fluctuations in the main gas flow path reaching the sensing mechanism. The damping of the sensing mechanism has a damping effect on the movement of the mechanical linkage, resulting in more stable valve operation. However, the amount of damping provided by this arrangement is dependent on the relative position of the mechanical linkage 2057 within the tubular guide 2007. If the mechanical linkage is off-center or not axially aligned with the guide, the damping effect is reduced, and this is unpredictable. The friction of the mechanical linkage against the tubular guide also creates hysteresis in the valve, creating a lag in the restoration of flow in the system after the valve has exhausted fluid to the atmosphere. Figure 24

[0464] To improve more predictable damping and reduced hysteresis, the concentric position of the connector portion 2025 / 2075 created by the integral overmolded diaphragm component helps to consistently keep the mechanical linkage 2057 in a central position within the tubular guide 2007.

[0465] Figure 31 ​​Another embodiment FCPRV 2100 is shown. FCPRV 2100 has similar features and functionality as FCPRV 2000, unless described below. Like numbers are used to indicate like parts. Figure 24

[0466] FCPRV 2100 includes a device inlet 2151 and a device outlet 2153, with a primary gas flow passage between the inlet and the outlet. A pressure relief mechanism between the inlet and the outlet operates substantially as described above with respect to the previous embodiment 2000 to vent at least a portion of the gas flow through the gas flow passage when the gas flow exceeds a pressure threshold. The valve member includes a diaphragm member 2105 as described above, although other embodiments can include alternative valve arrangements.

[0467] The sensing mechanism dynamically adjusts the pressure threshold based on a flow rate and / or pressure of a portion of the gas flow through the gas flow passage. The sensing mechanism includes a sensing member in the form of a sensing diaphragm member 2155 as described above with respect to the previous embodiment, although other embodiments can include alternative sensing member arrangements.

[0468] The sensing mechanism includes a mechanical link 2157 that couples the pressure relief valve and the sensing diaphragm member 2155, and a sealing sheath 2140 that substantially seals against the mechanical link 2157.

[0469] The sealing sheath 2140 is a flexible member, e.g., including an elastomeric material, and is attached to the mechanical link 2157 at a point on the link that is proximate to and spaced from the connection to the sensing diaphragm member 2155. The sealing sheath 2140 defines a central groove 2141 for receiving the mechanical link 2157. The walls of the groove 2141 seal against the mechanical link to substantially prevent or reduce fluid flow between the mechanical link 2157 and the sealing sheath 2140. Figure 32 to 33B

[0470] The diameter of the opening defined by the sealing sheath 2140 when the sealing sheath 2140 is uninstalled can be slightly smaller than the outer diameter of the mechanical link 2157, such that insertion of the mechanical link into the groove 2141 of the sealing sheath causes the groove to expand into a tensioned state, thereby providing the connection and seal between the sealing sheath and the mechanical link. The outer surface of the mechanical link at least at the connection between the mechanical link 2157 can be substantially cylindrical and smooth to improve the connection between the mechanical link 2157 and the sealing sheath 2140. In the illustrated embodiment, a majority of the length of the mechanical link 2157 includes a ribbed surface, however, in alternative embodiments, the mechanical link can be free of any ribs and instead can be substantially smooth.

[0471] ​​A first sensing chamber 2154a adjacent to the sensing diaphragm 2173 is defined by a wall 2110a of the valve body 2110. The wall defines a first aperture 2110b for receiving the mechanical linkage 2157, which is wider than the mechanical linkage. A sealing boot 2140 extends through the aperture 2110 and seals against the wall 2110a.

[0472] In the illustrated embodiment, the rim of the first aperture 2110b includes a lip or flange that extends substantially perpendicular to the sensing chamber wall 2110a. The lip 2110c acts as a retention mechanism to retain the sealing boot 2140 to the aperture 2110b. The base 2145 of the sealing boot 2140 extends around the lip, abutting the lip to seal. The inner diameter of the base 2145 of the sealing boot 2140 can be slightly smaller than the outer diameter of the lip 2110c of the aperture rim when the sealing boot 2140 is not installed, such that insertion of the sealing boot 2140 over the lip causes the base of the sealing boot to expand into tension, thereby increasing the connection between the sealing boot and the lip 2110c. The base 2145 of the sealing boot 2140 includes a thickened lip region to provide a tighter seal to the aperture lip.

[0473] The damping diaphragm 2140 includes a flexible body 2143 that extends from the base 2145 of the sealing boot to a central groove 2141. In the illustrated embodiment, the flexible body is arcuate in a convex manner relative to the first chamber. The arcuate flexible body 2145 allows axial movement of the mechanical linkage 2157 relative to the wall 2110 of the sensing chamber 2154a while maintaining a seal between the mechanical linkage and the wall. The mechanical linkage 2157 is able to move through a range of movement to provide a desired adjustment range of biasing of the valve member.

[0474] The sealing boot 2140 provides negligible resistance to axial movement through the range of movement. That is, the mechanical linkage is able to move axially through the desired range of movement substantially unimpeded by the sealing boot 2140.

[0475] The sealing boot 2140 is resilient and resists buckling under axial loads sufficient to adjust the valve mechanism. In alternative embodiments, the sealing boot 2140 can include a pleated membrane instead of an arcuate wall to allow axial movement of the mechanical linkage.

[0476] The sealing boot 2140 can be formed of any suitable flexible material, such as an elastomer or a plastic material, for example, a thermoplastic elastomer (TPE), LSR (liquid silicone rubber), molded rubber, or another suitable material known in the art. Alternatively, one or more portions of the sealing boot 2140 can include a substantially rigid material (such as polypropylene) and a living hinge to enable flexing of the boot.

[0477] In the illustrated embodiment 2100, no guide groove is provided for the mechanical link 2157. A guide groove between the sensing diaphragm and the valve diaphragm is not necessary because flow along the mechanical link is substantially sealed off between the airflow passage and the first sensing chamber 2154a, so no guide groove is needed for damping purposes. However, in alternative embodiments, a guide groove can be provided for the mechanical link, where the mechanical link can slide axially in the groove, and a sealing boot is disposed at the end of the guide groove nearest the sensing diaphragm. In alternative embodiments, a sealing boot can be provided along the guide groove, for example a portion of the sealing boot can engage the wall of the guide groove, and another portion of the sealing boot can seal against the mechanical link.

[0478] The first sensing chamber 2154a adjacent the sensing diaphragm is in fluid communication with the inlet 2151 to sense pressure upstream of the flow restriction. Because the space around the mechanical link 2157 is sealed by the sealing boot 2140, passage into the first sensing chamber 2154a is provided elsewhere. In the illustrated embodiment, a damping orifice 2147 is provided in the chamber wall 2110a to allow fluid communication with the inlet 2151.

[0479] Preferably, the passage 2147 into the first sensing chamber 2154a from the inlet 2151 is small and / or restricted, thus creating a resistance to flow by reducing fluctuations from the main airflow passage reaching the sensing member and damping the flow into the sensing mechanism 2050. The damping of the sensing mechanism has a damping effect on the movement of the mechanical link, resulting in more stable valve operation. In the illustrated embodiment, the damping orifice 2147 has a diameter of between 0 mm and 10 mm, with smaller orifices providing increased damping. In alternative embodiments, the wall 2154a of the sensing chamber can include multiple damping orifices. In embodiments with multiple damping orifices, the orifices can be smaller than in embodiments with a single damping orifice to provide a similar level of damping. The wall 2154a can further include a boss at each orifice that extends through the length of the groove defined by the orifice and thereby increases the resistance to flow through the orifice.

[0480] Figure 41 Another embodiment, FCPRV 2500, is shown. FCPRV 2500 has similar features and functionality as FCPRV 2100 of Figure 31 described below. Like numbers are used to indicate like parts having the addition 400.

[0481] In this embodiment, a guide channel 2507 for the mechanical link 2557 can optionally be provided with a gap provided between the surface of the mechanical link and the inner surface of the guide channel. Preferably, the gap is more than 0 mm, and more preferably, the gap is about 1 mm. A sealing boot 2540 is provided on the mechanical link 2557 to prevent gas from flowing out of the guide channel 2507 into the first sensing chamber 2554a.

[0482] Reference is made to Figure 42 the detailed view of FIG. 25B, the boot 2540 is mounted to the mechanical link 2557 such that the boot 2540 moves in coordination with the mechanical link. The boot 2540 is mounted to the mechanical link via an outwardly extending annular flange 2508 on the mechanical link. The boot 2540 has a complementary annular recess on the inner surface that receives the flange. The boot 2540 is a flexible, resilient member, preferably comprising an elastomer. The use of an elastomer advantageously enables the boot 2540 to be stretched over the flange 2508 to assemble the boot and the mechanical link. Compression forces in the boot 2540 keep the boot engaged with the flange 2508 to substantially seal the connection between the boot and the mechanical link.

[0483] The boot 2540 includes a tapered portion 2540a that has an edge that abuts against the surface of the valve body wall 2510 that defines the first sensing chamber 2554a. The tapered portion 2540a abuts the chamber wall 2510a around the end opening of the guide channel 2507.

[0484] The valve seat 2504 opposite the sealing boot 2540 prevents the mechanical link 2557 from moving away from the valve seat 2504 toward the sensing member 2543, and thereby prevents the boot 2540 from lifting out of contact with the chamber wall 2510a. The inward taper of the tapered portion 2540a and the resilient nature of the boot 2540 ensure that the boot 2540 remains in contact with the chamber wall 2510a to substantially seal the flow into the sensing chamber 2554a from the guide channel 2507 when the valve 2523 is lifted from the valve seat 2504 and when it is lowered again. The tapered portion 2540 of the boot 2540 is thinner in wall thickness than the portion of the boot adjacent the flange 2508. This reduced thickness minimizes any resistance to axial movement from the boot 2540.

[0485] Figure 43 Another embodiment, FCPRV 2600, is shown. The FCPRV 2600 has similar features and functionality as the FCPRV 2100 of Figure 31 FIG. 21, unless described below. Like numbers are used to indicate like parts having additive 500.

[0486] In this embodiment, a sealing shroud 2640 seals the end of the mechanical linkage guide channel 2607 provided adjacent to the valve diaphragm 2623, thereby preventing gas flow from the main passage into the guide channel. The guide channel 2607 is instead in fluid communication with the first sensing chamber 2654a.

[0487] With reference to the detailed view of Figure 44 A first portion of the sealing shroud 2640 is mounted to the mechanical linkage 2657 to move in concert with the mechanical linkage, and a second portion of the sealing shroud 2640 is mounted to the guide channel 2607.

[0488] The shroud 2640 is mounted to the mechanical linkage via an outwardly extending annular flange 2608 provided on the mechanical linkage 2657. In alternative embodiments, the shroud 2640 can be attached to the mechanical linkage in other ways, for example, by overmolding the shroud to the linkage. The shroud 2540 has a complementary annular recess on an inner surface that receives the flange 2608. The shroud 2640 is a flexible, resilient member, preferably comprising an elastomer. The use of an elastomer advantageously enables the shroud 2640 to be stretched over the flange 2608 to assemble the shroud and mechanical linkage 2657, and to be stretched over the guide channel 2607 to assemble the shroud 2640 to the guide channel 2607. Compression forces in the shroud 2640 keep the shroud 2640 engaged with the flange 2508 and the guide channel 2607 to substantially seal the respective connections. In alternative embodiments, the guide channel can be shorter than in the illustrated embodiment, and the shroud 2640 can be positioned closer to the sensing member 2643.

[0489] The shroud 2640 includes a necked portion 2640a between the two connection portions having a wall thickness that is thinner than the wall thickness of the portion of the shroud adjacent to the flange 2508. The necked portion 2640 includes a U-shaped cross-section, or is otherwise folded over to allow the mechanical linkage and guide channel connection portions to move away from each other. As the connection portions move away from each other, the necked portion 2640a straightens, and the bend in the necked portion increases again as the connection portions move back toward each other. This prevents the transfer of tension between the mechanical linkage and the guide channel during normal use.

[0490] Figure 41 to 44 In the two embodiments 2500, 2600, one or more damping orifices 2547, 2647 are provided in the wall 2510a, 2610a of the first sensing chamber. In these embodiments, the damping arrangement is provided by the combination of the damping orifice and the sealing shroud.

[0491] As an alternative to a sealing shroud, other embodiments of the FCPRV can include alternative means of sealing around the mechanical linkage to prevent fluid from leaking along the mechanical linkage into the first sensing chamber. Figure 34and 35 An embodiment FCPRV 2200 is illustrated in which the mechanical link is guided in a guide channel 2207. FCPRV 2200 has similar features and functionality as FCPRV 2100 of FIG. 21 and 32, unless described below. Like numbers are used to indicate like parts having an additive 100. Figure 31

[0492] The guide channel 2207 is a tubular guide. In the illustrated embodiment, the length of the tubular guide is short compared to the length of the mechanical link, e.g., about 25% less than the length of the link. However, in alternative embodiments, the guide can be longer, e.g., the guide can extend along most of the length of the link.

[0493] To seal around the mechanical link 2257 to prevent gas from leaking along the mechanical link into the first sensing chamber 2254a, the guide channel 2207 contains a viscous fluid, e.g., grease. The viscous fluid fills the space between the inner surface of the guide channel and the surface of the mechanical link, and allows the mechanical link 2257 to move axially within the channel 2207 while sealing the channel to prevent gas from flowing along the guide channel. The viscous fluid is preferably a low shear fluid to minimize any resistance to the axial movement of the mechanical link. However, in some embodiments, the viscous fluid can additionally dampen the movement of the mechanical link by providing resistance to the axial movement of the link.

[0494] Preferably, the fluid is a low strength, high viscosity fluid that is easily sheared but exhibits a high resistance to shear. In some embodiments, the fluid is a fluid with Bingham plastic properties, e.g., with a fixed shear strength; or a dilatant fluid with non-Newtonian properties, e.g., in which the viscosity increases with applied shear stress.

[0495] The viscous fluid provides a predictable amount of hysteresis to the FCPRV. Higher levels of damping are generally provided by the use of higher viscosity fluids. If reduced static force and residual tension are desired, a thinner layer of viscous fluid (e.g., using a narrower guide channel) or a shorter length of grease (e.g., by use of a shorter guide channel 2207) can be used.

[0496] In some embodiments, a membrane or seal can optionally be provided at one or both ends of the channel to contain the viscous fluid within the channel while still allowing axial movement of the mechanical link.

[0497] A damping orifice 2247 is provided in the chamber wall 2110a to allow fluid to flow from the valve inlet 2251 into the first sensing chamber 2254a. The damping orifice can contain a filter, such as a porous material over the orifice, to create increased resistance to flow through the orifice 2247. ​

[0498] Preferably, the passage 2247 into the first sensing chamber 2254a from the inlet 2251 is small and / or restricted, thus creating a resistance to flow and damping the flow into the sensing mechanism 2250 by reducing the fluctuations from the main airflow path reaching the sensing member. The damping of the sensing mechanism has a damping effect on the movement of the mechanical linkage, resulting in more stable valve operation. In alternative embodiments, the walls 2154a of the sensing chamber can include a plurality of damping apertures.

[0499] Figure 36 and 37 Two embodiments of FCPRVs 2300, 2400 are schematically illustrated, including a magnetic arrangement that damps the movement of the mechanical linkage 2357, 2457. The FCPRVs 2300, 2400 have similar features and functionality to the FCPRV 2100 of Figure 31 and 32 described below. Like numbers are used to indicate like parts having the addition 200 or 300 respectively.

[0500] In the first embodiment shown in Figure 36 , the magnetic arrangement includes a conductive coil 2333 that extends along the length of the mechanical linkage 2357 that couples the sensing diaphragm 2355 to the valve diaphragm 2305. The conductive coil is electrically connected to a resistor.

[0501] The magnets are arranged to induce a current in the coil upon axial movement of the mechanical linkage. The magnets are in the form of a ring, and surround the mechanical linkage. The magnets can be permanent magnets or electromagnets.

[0502] The resistor dissipates heat generated by the induced current in the coil. The resistor provides a 'load' for the induced current, which creates an effective resistance to movement of the mechanical linkage and the conductive coil, thereby damping the movement of the pressure relief valve and / or the sensing mechanism. In Figure 37 an alternative embodiment shown in , the magnetic arrangement includes an electrically conductive member that is mounted to the mechanical linkage 2457. In this embodiment, the electrically conductive member is a ring 2434 that includes an electrically conductive material, such as copper. The ring 2434 is fixed to the mechanical linkage 2457 at a point intermediate the opposite ends of the mechanical linkage, for example at the midpoint of the linkage.

[0503] First and second magnets 2437a, 2437b are provided within the body of the pressure relief device 2400, and are fixed relative to the body. In the embodiment shown, the first and second magnets 2437a, 2437b are ring magnets that surround the mechanical linkage 2457, such that the mechanical linkage 2457 is axially moveable within the ring opening.

[0504] Each ring magnet 2437a, 2437b defines a positive and negative pole. The ring magnets are positioned such that the positive pole of the first ring magnet 2437a is closest to the negative pole of the second ring magnet 2437b to thereby create a magnetic field extending between the first and second ring magnets.

[0505] The ring magnets 2437a, 2437b are preferably the same size and strength, and are arranged to be coaxial and spaced apart. The conductive ring 2434 on the mechanical link 2457 is positioned intermediate the two ring magnets 2437a, 2437b, in the generated magnetic field. The magnetic field provides resistance to movement of the conductive ring 2434 towards one of the ring magnets 2437a, 2437b, thereby providing resistance to movement of the mechanical link 2457.

[0506] The first and second ring magnets 2437a, 2437b can comprise electromagnets, in which the strength of the magnetic field is adjustable by varying the current through the electromagnets. Alternatively, the ring magnets 2437a, 2437b can be permanent magnets.

[0507] Figure 38 is a view of the pressure relief valve described above, showing the valve housing containing two chamber caps 2012. The valve chamber caps 2012 are secured in place to cover the valve body and internal components of the valve and form the second valve and sensing chambers. The valve housing contains ribs or other positioning features on the inner surface of each cap 2012 to help position the valve body 2010 correctly within the caps 2012. These ribs or positioning features help to accurately position the valve body within the housing. Accurate positioning is important because the first of the chamber caps 2012 defines the wall of the second sensing chamber 2154b that is needed for flow and / or pressure compensated relief from the valve. Misalignment of the valve body and chamber caps can cause variations in the sensing chamber that can result in inconsistent or unreliable flow and / or pressure compensation.

[0508] In some embodiments, the two chamber caps 2012 can be ultrasonically welded together to prevent access to the interior of the FCPRV. Preventing access to the valve can help to ensure that the operation of the valve, including flow and / or pressure compensation, is not intentionally or accidentally altered, for example by maintenance of the valve.

[0509] In other embodiments, the two housing caps 2012 can be ultrasonically welded, tightened or otherwise permanently or removably fastened together. In Figure 39 In the embodiment shown in FIG. 21 1 2, the chamber caps 2112 each provide a plurality of apertures 2014 for receiving fasteners, such as threaded fasteners. In cases where removable fasteners are used, the heads of the fasteners can be covered, for example using screw caps or plugs, to conceal the screws and prevent general access to the interior of the FCPRV.

[0510] As in the embodiment shown in FIG. 21 1 2, the chamber caps 2112 each provide a plurality of apertures 2014 for receiving fasteners, such as threaded fasteners. In cases where removable fasteners are used, the heads of the fasteners can be covered, for example using screw caps or plugs, to conceal the screws and prevent general access to the interior of the FCPRV.Figure 40 In use, the pressure relief valve is preferably arranged in a vertical orientation during use or operation, with the longitudinal axis of the valve extending from the inlet 2151 to the outlet 2153 being substantially perpendicular to the ground surface. In the vertical orientation, the sensing and valve diaphragm are in a substantially vertical plane. This eliminates or substantially reduces the effect of gravity on the operation of the diaphragm. Gravity would otherwise affect the valve in a horizontal orientation due to the weight of the diaphragm components and the weight of the mechanical linkage. In other embodiments, the pressure relief valve is arranged in a horizontal orientation during use or operation, with the longitudinal axis of the valve being substantially parallel to the ground surface. In some embodiments, the pressure relief valve is arranged in an inclined orientation, with the longitudinal axis of the valve being at an angle to the ground surface. When the valve is in a vertical or inclined orientation, the inlet 2153 is preferably arranged above the outlet 2153. In other embodiments, when the valve is in a vertical or inclined orientation, the outlet 2153 is arranged above the inlet 2151. Advantageously, the vertical orientation prevents any liquid that can be present in the system from entering the valve relief outlet and potentially affecting the gas flow through the valve. The vertical orientation of the valve allows the flange 2060 of the coupler 2059 to be positioned above the inlet 2151, providing a surface for liquid to fall onto without entering the interior of the valve via the inlet 2151.

[0511] The inlet 2051 is preferably positioned above the outlet 2053 and is coupled to the gas supply 12 via the flow meter 19. The gas supply 12 can be a wall gas source. The outlet 2053 is positioned below the inlet 2051 and is coupled to the conduit 14 for supplying the gas exiting the outlet 2053 to the patient. In the arrangement shown, the inlet 2051 and the outlet 2053 are coaxial and are vertically aligned.

Claims

1. A connector configured for use downstream of a pressure relief valve, the connector comprising: a connector body having an inlet and an outlet defining a gas flow passage therebetween; the connector body configured to be removably connected to a downstream side of a second connector and having an overlap portion configured to overlap a portion of the second connector when connected; and an access passage extending through the overlap portion to the gas flow passage, the access passage configured to communicate with a gas spill line in the pressure relief valve; wherein the connector configured for gas flow from the inlet to the outlet, the inlet arranged to receive gas flow from a flow source and the outlet arranged to provide gas to a patient.

2. The connector of claim 1, wherein the access passage comprises an orifice to be in fluid communication with the gas flow passage to sense pressure in the gas flow passage.

3. The connector of claim 1, wherein the gas flow passage is defined at least in part by a wall, and the access passage comprises an orifice in the wall of the connector.

4. The connector of claim 1, further comprising a cavity-forming portion configured to form a cavity with the second connector.

5. The connector of claim 4, wherein the cavity-forming portion comprises an arcuate surface.

6. The connector of claim 4, wherein the cavity-forming portion is a recess in a surface of the connector body.

7. The connector of claim 4, wherein the cavity-forming portion is in fluid communication with the gas flow passage via the access passage.

8. The connector of claim 4, wherein the cavity-forming portion has a longitudinal dimension substantially parallel to a direction of gas flow in the gas flow passage.

9. The connector of claim 4, wherein the connector is configured to be connected to the second connector by a male-female connection.

10. The connector of claim 9, wherein the connector comprises a female connector configured to receive a portion of the second connector.

11. The connector of claim 4, further comprising a first sealing mechanism configured to form a first seal with a portion of the second connector.

12. The connector of claim 11, wherein the first sealing mechanism comprises one or more of: a face seal, an O-ring, a lip seal, a dust seal, or a sealing surface.

13. The connector of claim 11, wherein the overlap portion comprises the first sealing mechanism.

14. The connector of claim 11, wherein the first sealing mechanism comprises an inner or outer sealing surface for friction / interference fit with the second connector.

15. The connector of claim 11, wherein the access passage and / or cavity-forming portion are arranged upstream of the first sealing mechanism.

16. The connector of claim 11, further comprising a second sealing mechanism configured to form a second seal with a portion of the second connector.

17. The connector of claim 16, wherein the cavity-forming portion is between the first sealing mechanism and the second sealing mechanism.

18. The connector of claim 16, wherein the access channel is positioned between the first sealing mechanism and the second sealing mechanism.

19. The connector of claim 16, wherein the second sealing mechanism comprises one or more of a face seal, an O-ring, a lip seal, a dust seal, or a sealing surface.

20. The connector of claim 16, wherein the overlap portion comprises the second sealing mechanism.

21. The connector of claim 16, wherein the second sealing mechanism comprises an inner or outer sealing surface for friction / interference fit with the second connector.

22. The connector of claim 1, wherein a portion and / or surface of the connector is tapered.

23. The connector of claim 22, wherein a cross-sectional area of the connector near the inlet is less than a cross-sectional area of the connector near the outlet.

24. The connector of claim 1, further comprising one or more alignment features.

25. The connector of claim 2, wherein the orifice is arranged substantially parallel or substantially perpendicular to a direction of airflow in the airflow passage.

26. The connector of claim 2, wherein the orifice is arranged radially around the airflow passage.

27. The connector of claim 2, wherein the connector further comprises a stepped portion and the orifice is arranged on the stepped portion.

28. The connector of claim 2, wherein the orifice is in fluid communication with the airflow passage via another orifice, the orifice being in fluid communication by a trench.

29. The connector of claim 16, further comprising a flow restriction.

30. The connector of claim 29, wherein the flow restriction is provided at a terminal end of the connector.

31. The connector of claim 30, wherein the flow restriction is arranged in a recess.

32. The connector of claim 29, wherein the flow restriction is provided by a constriction spaced apart from a terminal end of the connector.

33. The connector of claim 32, wherein the constriction is a venturi.

34. The connector of claim 29, wherein the connector body tapers towards a terminal end, tapering from a larger diameter to a smaller diameter.

35. The connector of claim 1, further comprising a stopper.

36. The connector of claim 35, wherein the stopper is or comprises a collar.

37. The connector of claim 36, wherein a surface of the collar is configured to form a face seal with a surface of the second connector.

38. The connector of claim 1, further comprising a radial gap proximate a terminal end of the connector.

39. The connector of claim 16, wherein the lumen-forming portion tapers relative to a direction of gas flow.

40. The connector of claim 39, wherein the gas flow passage is or comprises a pressure line.

41. The connector of claim 40, wherein the connector tapers from a terminal end, tapering from a larger diameter to a smaller diameter.

42. The connector of claim 40, wherein the connector is configured to be coupled to the pressure relief valve.

43. The connector of claim 42, further comprising an engagement mechanism configured to couple the connector to the pressure relief valve.

44. The connector of claim 42, wherein the connector is integral with the pressure relief valve.

45. The connector of claim 43, wherein the pressure relief valve is a flow relief valve and / or a pressure-compensated relief valve.

46. The connector of claim 43, wherein the pressure line is in fluid communication with a sensing chamber of the pressure relief valve.

47. The connector of claim 46, wherein the pressure relief valve comprises a sensing member configured to sense a pressure differential between the sensing chamber and a main gas flow passage providing gas flow to a patient.

48. The connector of claim 47, wherein movement of the sensing member changes an exhaust pressure of a valve member.

49. The connector of claim 40, wherein the pressure line is a first pressure line, and the connector further comprises a second pressure line upstream of the first pressure line.

50. The connector of claim 40, wherein the connector is configured to be coupled to a circuit component.

51. The connector of claim 50, further comprising an engagement mechanism configured to engage the connector with the circuit component.

52. The connector of claim 49, wherein the first pressure line and the second pressure line are each coupled to a pressure sensing mechanism.

53. The connector of claim 29, wherein the access passage is provided at or immediately adjacent and downstream of the flow restriction.

54. The connector of claim 1, wherein an outer dimension of an inlet end of the connector is smaller than an outer dimension of an outlet end of the connector.

55. A connection assembly configured to be used downstream of a pressure relief valve, the connection assembly comprising: a first connector comprising: a connector body having an inlet and an outlet defining a first connector gas flow passage therebetween, wherein the first connector is configured for gas flow from the inlet to the outlet, the inlet being arranged to receive gas flow from a flow source and the outlet being arranged to provide gas to a patient; a second connector comprising: a connector body having an inlet and an outlet defining a second connector gas flow passage therebetween, wherein the second connector is configured for gas flow from the inlet to the outlet, the inlet being arranged to receive gas flow from a flow source and the outlet being arranged to provide gas to a patient; and a flow restriction disposed between the first connector and the second connector, the flow restriction being configured to restrict gas flow from the first connector to the second connector. a second connector comprising: a connector body having an inlet and an outlet defining a second connector gas flow passage therebetween, and an overlap portion; wherein the first and second connectors are configured to be removably connected such that the overlap portion of the first connector and the overlap portion of the second connector are continuous to form an overlap connection and provide an assembly gas flow passage; and an access passage extending through the overlap connection to the assembly gas flow passage, the access passage configured to be in communication with a gas spill line in the pressure relief valve.

56. In combination for use in a respiratory system, a conduit and a connector according to claim 1.

57. In combination for use in a respiratory system, a pressure relief valve and a connector according to claim 1.

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