User interface and system for supplying gas to the airway

Abstract

A respiratory system adapted to provide multiple types of respiratory therapy to a user, as well as a patient interface and device for such a system, is provided. [Solution] The present invention relates to a respiratory system including a first patient interface for delivering a first gas flow to a patient, a second patient interface for delivering a second gas flow to the patient, and a device and / or sensing mechanism configured to facilitate switching of the system between a first breathing mode in which the device enables delivery of the first gas flow to an outlet of the first patient interface when the second patient interface is not present on the patient, and a second breathing mode in which the device reduces or stops delivery of the first gas flow to the outlet of the first patient interface when the second patient interface is positioned on the patient along with the first patient interface.

Description

Technical Field

[0001] The present disclosure relates to a user interface for conveying gas to and / or from a user and a respiratory therapy system including the user interface, and more particularly, but not limited to, a respiratory system adapted to provide a plurality of types of respiratory therapy to a user, as well as a patient interface and apparatus for such a system.

Background Art

[0002] During anesthesia, or sedation, or more generally during certain medical procedures, a patient may lose their respiratory function. Prior to a medical procedure, a healthcare professional can pre-oxygenate the patient to provide a reserve of oxygen saturation, which is generally done using a bag and face mask. After induction of general anesthesia, the patient must be intubated and ventilated. In some cases, intubation is completed within 30 to 60 seconds, but in other cases, particularly when the patient's airway is difficult to intubate (e.g., due to cancer, severe trauma, obesity or spasm of the neck muscles), the time taken for intubation is significantly longer. Pre-oxygenation alleviates the decline in oxygen saturation, but for a long intubation procedure, it is necessary to interrupt the intubation process and reapply the face mask to raise the patient's oxygen saturation to a sufficient level. In a difficult intubation process, the intubation process may be interrupted several times, which is time-consuming and exposes the patient to significant health risks. After about three intubation attempts, the medical procedure will be aborted.

[0003] In procedures where multiple respiratory assistance systems are required, there may be a concern that the combined use of the assistance systems can cause the delivery of excessive pressure (e.g., when a cannula is placed in a patient and an anesthesiologist attempts to deliver assistance through a mask placed over the cannula).

[0004] Furthermore, switching between different assistive systems can be time-consuming or difficult. Therefore, it can be said that it is desirable to have a configuration that allows for easy switching between respiratory aids, for example, between high-flow assistance and respiratory assistance using a face mask and bag. Also, it can be said that it is desirable if the gas flow can be quickly and easily blocked or reduced.

[0005] In this specification, when external information sources including patent specifications and other documents are referenced, it is generally for the purpose of providing a context for considering the features of the present invention. Unless otherwise specified, the reference to such information sources should not be construed in any jurisdiction as admitting that such information sources are prior art or form part of the common general knowledge in the art.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The object of the present disclosure is to provide a respiratory therapy system, or an apparatus or patient interface therefor, which provides at least some assistance in providing alternative means or useful options for industry / the public.

Means for Solving the Problems

[0007] In one aspect, the present disclosure relates to a respiratory device for providing respiratory assistance to a patient, the device comprising a nasal interface and a gas conduit for delivering a gas flow to an outlet of the nasal interface, and a device and / or sensing mechanism adapted to configure the device between a first configuration for providing a first level of gas flow at the outlet and a second configuration for providing a second level of gas flow at the outlet (the second level being less than the first level), wherein the device and / or sensor mechanism is located at the nasal interface or at or near the patient end of the conduit.

[0008] In a further aspect, the present disclosure relates to a respiratory device for providing respiratory assistance to a patient, the device comprising: a nasal interface and a gas conduit for delivering gas flow to the outlet of the nasal interface, and a device adapted to configure the gas conduit between a first configuration for providing a first level of gas flow at the outlet and a second configuration for providing a second level of gas flow at the outlet (the second level being less than the first level); a sensing mechanism including a first pressure sensor located downstream of the device and a second pressure sensor located upstream of the device, wherein the first or second configuration of the conduit can be determined based on signals or outputs generated from the first and second sensors.

[0009] The first configuration may be an open configuration and the second configuration may be a partially or substantially closed configuration, and the second level of gas flow is substantially less than the first level or is a gas flow with substantially zero flow rate.

[0010] The device may include a crushable portion of the gas conduit configured to transition between the first configuration and the second configuration.

[0011] The gas conduit may include a partition or a pair of partitions within the crushable portion, in the first configuration, a first level of gas flow is achieved by the conduit including a gap between the partition and the side wall of the conduit or between a pair of partitions, and in the second configuration, a second level of gas flow is achieved by the partition moving towards the side wall of the conduit or the partitions moving towards each other.

[0012] The crushable portion may be adapted to transition from the first configuration to the second configuration when (i) a second patient interface is located over the crushable portion or (ii) the user presses on the crushable portion.

[0013] The device may include a valve configurable between the first and second configurations.

[0014] In a second configuration, the valve can vent or divert at least a portion of the gas flow from the appliance.

[0015] The apparatus can include a pressure relief device that is in a closed or non-venting configuration in a first configuration and in an open or venting configuration in a second configuration, and can vent or divert at least a portion of the gas flow from the appliance.

[0016] The valve can vent or divert a portion of the gas flow away from the patient.

[0017] The valve can be adapted to switch from a first configuration to a second configuration when (i) a second patient interface is located on at least a component of the valve, or (ii) a user presses on at least a component of the valve.

[0018] The nasal interface can include the apparatus, or a gas conduit can be connected to or connectable to the nasal interface and include the apparatus.

[0019] In a further aspect, the present disclosure relates to a system for providing respiratory assistance to a patient, which includes a first respiratory assistance system including a first patient interface for providing a first gas flow to the patient, wherein the first patient interface can be positioned independently on the patient, wherein the system includes an apparatus and / or a sensing mechanism configured to facilitate switching between different respiratory modes of the system while the first patient interface remains positioned on the patient: - In a first respiratory mode, when a second patient interface is absent or removed from the patient and / or a second gas flow is blocked from delivery to the patient by the second patient interface, the apparatus can deliver the first gas flow to the outlet of the first patient interface, - In the second breathing mode, when the second patient interface is positioned on the patient together with the first patient interface and / or when the second gas flow is delivered to the patient by the second patient interface, the device reduces or stops the delivery of the first gas flow to the outlet of the first patient interface.

[0020] This system can include a second respiratory assistance system including a second patient interface for providing a second gas flow to the patient, wherein the first and second interfaces can each be independently positioned on the patient.

[0021] In a further aspect, the present disclosure relates to a system for providing respiratory assistance to a patient, which includes a first respiratory assistance system including a first patient interface for providing a first gas flow to the patient, a second respiratory assistance system including a second patient interface for providing a second gas flow to the patient, wherein the first and second interfaces can each be independently positioned on the patient, wherein the first respiratory assistance system includes a device and / or a detection mechanism, and while the first patient interface remains positioned on the patient, the device and / or the detection mechanism is configured to facilitate switching between different breathing modes of the system: - In the first breathing mode, when the second patient interface is absent or removed from the patient and / or when the delivery of the second gas flow to the patient by the second patient interface is stopped, the device can deliver the first gas flow to the outlet of the first patient interface, - In the second breathing mode, when the second patient interface is positioned on the patient together with the first patient interface and / or when the second gas flow is delivered to the patient by the second patient interface, the device reduces or stops the delivery of the first gas flow to the outlet of the first patient interface.

[0022] The first patient interface may be a nasal interface such as a nasal cannula, and the second patient interface may be a face mask or a mouth mask.

[0023] The device or sensing mechanism may be adapted to switch the system from the first mode to the second mode by closing or partially closing the gas conduit that provides the first gas flow to the outlet of the first patient interface.

[0024] The device or sensing mechanism may be adapted to switch the system from the second mode to the first mode by opening the gas conduit or by enabling the gas conduit to provide the first gas flow to the outlet of the first patient interface.

[0025] The first respiratory assistance system may include a first gas conduit and a device, the device including a crushable portion of the first gas conduit configured to transition between a first configuration for providing a first level of the first gas flow at the outlet and a second configuration for providing a second level of the first gas flow at the outlet (the second level being less than the first level), wherein upon the crushable portion transitioning from the first configuration to the second configuration, the system switches from the first respiratory mode to the second respiratory mode, wherein upon the crushable portion transitioning from the second configuration to the first configuration, the system switches from the second respiratory mode to the first respiratory mode, either or both.

[0026] The first configuration may be an open configuration and the second configuration may be a partially or substantially closed configuration, and the second level of the first gas flow is substantially less than the first level or is a first gas flow of substantially zero flow.

[0027] The crushable portion may be adapted to transition from the first configuration to the second configuration when the second patient interface is positioned over the crushable portion.

[0028] The second patient interface may be a face mask, and the crushable portion is adapted to be crushed into a second configuration by a mask seal of the face mask.

[0029] The crushable portion may be adapted to form a seal with the mask seal when in the second configuration, and / or the crushable portion is adapted to be crushed to enable the mask seal to form a seal with the patient's face.

[0030] The crushable portion may include a cross-section including a hinge-type or articulated or bellows-type or bellow-type conduit wall mechanism that enables the crushable portion to be crushed from a first configuration to a second configuration when a force or load acting on the crushable portion is applied.

[0031] The first patient interface may include a crushable portion of the first conduit, or the first gas conduit may be connected to or connectable to the first patient interface and includes a crushable portion of the first conduit.

[0032] The first respiratory assistance system may include an apparatus that may include a valve for controlling the delivery of a first gas flow to an outlet of the first patient interface, where the system switches from a first breathing mode to a second breathing mode by switching the valve between a first configuration for providing a first level of the first gas flow at the outlet and a second configuration for providing a second level of the first gas flow at the outlet (the second level being less than the first level).

[0033] The first patient interface may include a valve, or the first respiratory assistance system may include a first gas conduit for providing a first gas flow to the first patient interface, and the first gas conduit may include the valve.

[0034] The first configuration may be an open configuration, and the second configuration may be a partially or substantially closed configuration, and the second level of the first gas flow is substantially less than the first level or is a first gas flow of substantially zero flow rate.

[0035] In the second configuration, the valve may vent or divert at least a portion of the first gas flow from the first respiratory assistance system.

[0036] The valve may be a pressure relief device, may be in a closed or non-venting configuration in the first configuration, and may be in an open or venting configuration in the second configuration to vent or divert at least a portion of the first gas flow from the first respiratory assistance system.

[0037] The valve may vent or divert a portion of the first gas flow in a direction away from the patient.

[0038] The valve may be adapted to switch between the first configuration and the second configuration by applying a portion of the second patient interface against at least a component of the valve.

[0039] The second patient interface may be a face mask, and a portion thereof may be a mask seal of the face mask.

[0040] The system or apparatus may include a sensing mechanism that generates a signal or output to facilitate switching between the first and second configurations of the device.

[0041] The system or apparatus may include a sensing mechanism that generates a signal or output to facilitate switching between the first and second respiratory modes or configurations of the system or apparatus in response to a detected condition.

[0042] One or more sensors of the sensing mechanism may be associated with one or more of the following: i. The first patient interface or nasal interface, ii. The second patient interface, iii. Both the first and second patient interfaces, iv. An item associated with the first patient interface, v. An item associated with the second patient interface, vi. An item associated with both the first and second patient interfaces, vii. An item that will be associated with the patient.

[0043] One or more sensors may detect a change in the condition within the gas conduit and generate a signal or output, or the first respiratory assistance system includes a first gas conduit and one or more sensors detect a change in the condition within the first gas conduit and generate a signal or output.

[0044] The sensor may detect a change in pressure within the gas conduit or the first gas conduit and / or an occlusion of the gas conduit or the first gas conduit.

[0045] The first respiratory assistance system may include a device, and the sensor mechanism includes a first pressure sensor located downstream of the device, a second pressure sensor located upstream of the device, and a controller configured to determine when the system should switch or the timing at which it should switch between the first and second respiratory modes based on the signals or outputs generated from the first and second sensors.

[0046] The sensor may detect the in-situ co-use of a particular or a certain second patient interface with the first patient interface or a nasal interface.

[0047] When the first patient interface or nasal interface and the second interface are in-situ co-used, the sensor may be arranged to detect the pressure outside the first patient interface or nasal interface and inside a particular or a certain second patient interface.

[0048] The system receives the signal or output and, in response, the following system outcomes: A visual, or audible, or tactile, or haptic alarm or warning, - which indicates either one of the first and second breathing modes, or - which indicates a switch between the first and second breathing modes, or - one or more of alarms or warnings for notifying the user of a switch between the first and second breathing modes, or a controller adapted to operate or control one or more of a valve, or a flow generator, or a pressure relief device, including a flow control device for controlling a first gas flow to an outlet of a first patient interface.

[0049] The system can include a spacer component as a block or mount, the spacer component can include a channel or groove or passage for receiving a portion of a gas conduit, and a seal surface on which a seal of a second patient interface forms together with the patient's face.

[0050] The spacer component can be the first patient interface, the second patient interface, both the first and second patient interfaces, or an item associated with the patient.

[0051] The second patient interface includes a body (the body includes an opening or port that enables communication with a gas supply or gas source of the gas and / or communication from there to an internal volume of the second patient interface, the internal volume being defined by the inside of the body and the user's face), and can include a seal provided to create or form a seal between the body and the patient's face so that the internal volume becomes a sealed internal volume, and the seal can be adapted to create or form a seal between the body and the patient's face and can be adapted or configured to facilitate the gas conduit or the first patient interface extending between the body and the patient's face into the sealed internal volume.

[0052] The first respiratory assistance system may include a pressure relief device located upstream of the device to vent or divert at least a portion of the first gas flow from the first respiratory assistance system.

[0053] The first respiratory assistance system may include a one-way valve to prevent or reduce backflow from the second respiratory assistance system in the first respiratory assistance system.

[0054] The second patient interface may be a hand-held patient interface.

[0055] In a further aspect, the present disclosure relates to a first gas lumen adapted to receive gas from a gas source, and to a patient interface including the same, wherein a first portion of the first gas lumen is configured to transition from a first configuration in which a first level of gas can pass through the first portion of the first gas lumen to a second configuration in which a second level of gas can pass through the first portion of the first gas lumen.

[0056] The first portion of the first gas lumen may transition or expand between the first and second configurations based on a force applied to the outer wall of the first portion of the first gas lumen, or a relative level of force received by its inner wall.

[0057] The first portion of the first gas lumen may transition or expand between the first and second configurations based on the pressure level of the gas passing through the first portion of the gas lumen.

[0058] The first portion of the first gas lumen may be in the first configuration when gas having a pressure above a first predetermined pressure level is passing through the first gas lumen, and the first portion of the first gas lumen may be in the second configuration when gas having a pressure below the first predetermined pressure level is passing through the first gas lumen.

[0059] The first configuration may be substantially open, and the second configuration is substantially closed.

[0060] The first gas level may be higher than the second gas level.

[0061] The first portion of the first gas lumen may include a wall that is thinner than one or more walls of other portions of the first gas lumen.

[0062] The patient interface may further include a substantially smooth transition in thickness, or a substantially linear transition, between the wall of the first portion of the first gas lumen and one or more walls of other portions of the first gas lumen.

[0063] The first portion of the first gas lumen can include a wall that is more flexible than the walls of other portions of the first gas lumen, and preferably that (more flexible) wall is at least partially formed of a material that is more flexible than one or more walls of other portions of the first gas lumen.

[0064] The wall of the first portion of the first gas lumen may be configured to be substantially crushed or crushable when in the second configuration, or may not hold a gas or fluid passageway, or may not be substantially self-supporting.

[0065] The cross-sectional area of the first portion of the first gas lumen, as viewed along the length of the first gas lumen, may be substantially reduced (e.g., reduced to zero) when in the second configuration, and optionally may take on a substantially flat or flattened shape when in the second configuration.

[0066] The first portion of the first gas lumen may include an element adapted to limit compression of the first portion of the first gas lumen around, or within or beneath, the wall of the first portion of the first gas lumen.

[0067] This element can be configured to facilitate a minimal level of gas flow through the first portion of the first gas lumen, regardless of the configuration of the first portion of the first gas lumen. Optionally, such an element may be a reinforcing element.

[0068] The first gas lumen can include an element adapted to limit compression of the first gas lumen at or near the wall of the first gas lumen, the strength, thickness and / or width of this element decreasing at or near the first portion of the first gas lumen.

[0069] The patient interface can include a substantially smooth transition, or a substantially linear transition, in the strength, thickness and / or width of an element from a portion of the element that is at or near the first portion of the first gas lumen to one or more portions of the same or another element that are distal to the first portion of the first gas lumen.

[0070] The patient interface can further include a second gas lumen that extends along at least an interior region of the first gas lumen, passing through, being at, or being near the first portion of the first gas lumen.

[0071] The second gas lumen may be less compressible than the first portion of the first gas lumen, or may have a higher resistance to compression. In some such configurations, the wall of the second gas lumen is formed, at least in part, of a material that is more rigid or less flexible than the wall of the first portion of the first gas lumen. Optionally, when one or more elements are integrated, the second gas lumen may be formed by the one or more elements (such as a reinforcing element). For example, the reinforcing element may be shaped or configured to interact with the wall of the first gas lumen to provide the second gas lumen, or may be adapted in another way to do so, or the reinforcing element may be integrated in a configuration that forms the second gas lumen and, optionally, closes the first gas lumen.

[0072] The first portion of the first gas lumen may be wider than, larger than, or have a wider or larger cross-sectional surface area than other portions of the first gas lumen, or may be a bellows-type or enlarged local region.

[0073] The patient interface may further include a substantially smooth transition, or a substantially linear transition, of width or cross-sectional area or sides from the first portion of the first gas lumen to a portion of the first gas lumen distal to the first portion of the first gas lumen.

[0074] The patient interface may further include a pressure relief mechanism adapted to reduce the pressure of the gas within the first gas lumen when the first portion of the first gas lumen is in a second configuration.

[0075] In a further aspect, the present disclosure relates to a nasal cannula. The nasal cannula can include a first tubular section and at least one transnasal delivery element (e.g., at least one nasal prong) in fluid (e.g., pneumatic) communication with the first tubular section, wherein one or more of the at least one transnasal delivery element is adapted to be placed in one or more nostrils of a user; wherein the first tubular section includes a first gas lumen adapted to receive gas from a gas source; and wherein the first portion of the first gas lumen has a greater tendency to expand from a first configuration in which a first level of gas can pass through the first portion of the first gas lumen to a second configuration in which a second level of gas can pass through the first portion of the first gas lumen than other portions of the first gas lumen.

[0076] The at least one transnasal delivery element may be adapted to be placed in or located within one or more nostrils of the user in a non-sealing manner.

[0077] A flow manifold may be interposed between the first tubular section and the at least one transnasal delivery element.

[0078] At least one nasal delivery element may extend from the flow manifold.

[0079] The first portion of the first gas lumen may deploy between the first and second configurations based on the level of force applied to the outer or inner wall of the first portion of the first gas lumen (as received by the inner wall, for example).

[0080] The first portion of the first gas lumen may deploy between the first and second configurations based at least in part on the pressure level of the gas passing through the first portion of the gas lumen.

[0081] The first portion of the first gas lumen may be in the first configuration when a gas having a pressure above a first predetermined pressure level is passing through the first gas lumen, and the first portion of the first gas lumen may be in the second configuration when a gas having a pressure below the first predetermined pressure level is passing through the first gas lumen.

[0082] The first configuration may be a substantially open configuration, and the second configuration may be a substantially closed configuration.

[0083] The first gas level may be higher than the second gas level.

[0084] The first portion of the first gas lumen may include a wall that is thinner than one or more walls of other portions of the first gas lumen.

[0085] The nasal cannula may further include a substantially smooth transition in thickness between the wall of the first portion of the first gas lumen and one or more walls of other portions of the first gas lumen.

[0086] The first portion of the first gas lumen may include a wall that is at least partially formed of a material that is more flexible than the walls of other portions of the first gas lumen.

[0087] The wall of the first part of the first gas lumen can be configured to be substantially crushed or non-self-supporting in the second configuration.

[0088] The cross-sectional area of the first part of the first gas lumen, when viewed along the length of the first gas lumen, may substantially decrease (e.g., may decrease to zero) in the second configuration, and optionally may take a substantially flat or flattened shape or configuration in the second configuration.

[0089] The first part of the first gas lumen may include a reinforcing element adapted to limit the compression of the first part of the first gas lumen around, inside, or below the wall of the first part of the first gas lumen.

[0090] This reinforcing element can be configured to facilitate a minimum level of gas flow through the first part of the first gas lumen regardless of the configuration of the first part of the first gas lumen.

[0091] The first gas lumen can include a reinforcing element adapted to limit the compression of the first gas lumen at or near the wall of the first gas lumen, and the strength, thickness, and / or width of this reinforcing element decreases at or near the first part of the first gas lumen.

[0092] The nasal cannula can include a substantially smooth transition, or a substantially linear transition, in the strength, thickness, and / or width of the reinforcing element from a portion of the reinforcing element that is at or near the first part of the first gas lumen to one or more portions of the reinforcing element that are distal to or adjacent to the first part of the first gas lumen.

[0093] The first part of the first gas lumen may have a higher tendency to transition from a first configuration in which a first level of gas can pass through the first part of the first gas lumen to a second configuration in which a second level of gas can pass through the first part of the first gas lumen than other parts of the first gas lumen.

[0094] The nasal cannula may further include a second gas lumen that extends along at least an internal region of the first gas lumen, in or near a first portion of the first gas lumen.

[0095] The second gas lumen may be less compressible than the first portion of the first gas lumen.

[0096] At least a part of the wall of the second gas lumen may be formed of a material that is stiffer or less flexible than the wall of the first portion of the first gas lumen.

[0097] The first portion of the first gas lumen may be wider than other portions of the first gas lumen, or larger or wider or have a larger cross-sectional surface area compared thereto, or be a bellows-type or enlarged local region.

[0098] The nasal cannula may further include a substantially smooth or substantially linear transition in width from the first portion of the first gas lumen to a portion of the first gas lumen that is distal to the first portion of the first gas lumen.

[0099] The nasal cannula may further include a pressure relief valve, device or mechanism adapted to reduce or relieve the pressure of the gas in the first gas lumen when the first portion of the first gas lumen is in a second configuration.

[0100] The nasal cannula may further include one or more attachment structures that are fixed or attached or connected to one or more portions facing the user of the nasal cannula, and the one or more attachment structures are adapted to fasten or attach or connect the nasal cannula to the user's face (optionally in a detachable manner).

[0101] The one or more attachment structures may be adapted to engage with one or more immobilization structures fixed to the face for fastening the nasal cannula to the face, for example in a detachable manner.

[0102] At least one nasal delivery element may have a shape or an angle such that it extends inwardly towards the septum of the user.

[0103] At least one nasal delivery element may have a shape or an angle such that the tip of the at least one nasal delivery element faces towards the back of the head of the user during use, or has an angle such that it directs the flow of the supplied gas towards the back or more medial region of one or more nostrils of the user.

[0104] A respiratory assistance system is disclosed, which can include a first respiratory assistance subsystem and a second respiratory assistance subsystem, wherein the first respiratory assistance subsystem includes a patient interface as described, and the system is configured to switch the delivery of respiratory assistance to the patient from the first subsystem to the second subsystem when the first portion of the first gas lumen of the patient interface transitions from the first configuration to the second configuration.

[0105] The first respiratory assistance subsystem may be a high-flow system.

[0106] The first respiratory assistance subsystem may further include the nasal cannula as described.

[0107] The second respiratory assistance subsystem may include a face mask.

[0108] The first portion of the first gas lumen may transition from the first configuration to the second configuration when compressed by the seal of the face mask.

[0109] A method of switching between two respiratory assistance modes is disclosed, which includes delivering respiratory assistance to a patient using a patient interface as described for the first respiratory assistance mode, and transitioning the first portion of the first gas lumen from the first configuration in which the first respiratory assistance mode delivers respiratory assistance to the patient to the second configuration in which the second respiratory assistance mode delivers respiratory assistance to the patient.

[0110] The first mode may be a high-flow therapy mode.

[0111] In a further aspect, the present disclosure relates to a conduit including a crushable portion, the crushable portion including a cross-section including a hinge-type or articulated or bellows-type or bellow-type conduit wall mechanism that enables the crushable portion to be crushed from a first state to a second state when a force or load acting on the crushable portion is applied.

[0112] This cross-section can include a single-fold portion on the side of the crushable portion that extends between the outside of the conduit and the inside of the conduit (the inside of the conduit contacts the patient's face during use), and The fold portion includes a pair of side portions that, in the first state, extend outward from the fold point and present an acute or obtuse angle facing outward, and in the second position, the cross-section deforms at the fold point and the pair of side portions come into contact to crush the crushable portion into the second state.

[0113] This cross-section can include a first said single-fold portion on a first side of the crushable portion and a second said single-fold portion on a second side of the crushable portion, the second side being on the opposite side of the first side, and the first and second fold portions extending between the outside of the conduit and the inside of the conduit.

[0114] This cross-section can include a single-fold portion on a first side of the crushable portion and a second fold point on a second side of the crushable portion, the second side being on the opposite side of the first side, and the outside of the conduit and the inside of the conduit extending from the second fold point.

[0115] The inside and outside of the conduit can be folded together at the second fold point when transitioning from the first configuration to the second configuration.

[0116] The angle may be an acute angle.

[0117] The angle may be less than 60 degrees, or 55 degrees, or 50 degrees, or 45 degrees, or 40 degrees, or 35 degrees.

[0118] In the second state, the crushable portion can be crushed so that the outer surfaces of the side portions contact each other.

[0119] In the second state, the inner surface of the side portion contacts the inner surfaces inside and outside the conduit.

[0120] In another aspect, according to the present disclosure, a conduit or at least a partial length of a conduit is provided for use as part of a respiratory therapy delivery system, the conduit or partial length of the conduit including: At least one foam or array of foams supports or forms part of the conduit wall, and the inner surface of the conduit wall forms the lumen or gas flow path of the conduit, The at least one foam or array of foams is biased to preferentially maintain the lumen or gas flow path in a first state, the first state being a substantially open or substantially uncrushed conduit wall state, And the conduit or partial length of the conduit including the at least one foam or array of foams is configured to distort or buckle from the first state to a second state in response to a force or load applied to the outer surface of the conduit wall including the at least one foam or array of foams, The second state is a substantially closed or substantially crushed conduit wall state or a case where the lumen or gas flow path is substantially blocked or obstructed with respect to the gas flow passing therethrough.

[0121] The at least one foam or array of foams can be substantially infinitely distortable or bucklable in response to the application of a force or load.

[0122] The distortion or buckling of at least one form or an array of forms from a first state to a second state can be a predetermined distorted or buckled arrangement or array or configuration of at least one form or an array of forms.

[0123] The force or load applied to the outer surface of the conduit can be sufficient to overcome the biasing during use.

[0124] The force or load applied to the outer surface of the conduit can be sufficient to cause distortion or buckling of at least one form or an array of forms during use.

[0125] The second state can be a preferred predetermined reorganization (or rearrangement or repositioning) of at least one form or an array of forms.

[0126] In the second state, regardless of whether the inner surfaces of the conduit walls come into contact with each other or are substantially adjacent to each other, they overlap and become integrated, or at least partially overlap and become integrated, and a substantially closed or substantially crushed conduit wall state or lumen or gas flow path through which the gas flow passes is provided such that it is substantially blocked or obstructed with respect to the gas flow.

[0127] The form or an array of forms may be biased towards the first state.

[0128] The forms of the array of forms can have the ability to distort or buckle from the first state towards the second state when a force or load is applied, but when the force or load is reduced or removed, the form or an array of forms can return or recover the conduit to the first state.

[0129] The form or an array of forms may be independent of the conduit wall or the inner wall surface. That is, one or more forms are not attached or connected to the conduit wall or its inner surface.

[0130] The foam may be a helical or helically wound or coiled member having a pitch angle of about 20° to about 70°, or about 25° to about 65°, or about 35° to about 55°, or about 45° from a horizontal longitudinal axis extending along at least a portion of a conduit or a conduit including the foam or an array of foams (the pitch angle being the angle between each turn or coil of the member), or an angle with respect to the conduit wall.

[0131] The foam may be a helical or helically wound or coiled member having a pitch of greater than about one-fourth the inner diameter of the conduit to about 10 times the inner diameter of the conduit, or about one-half the inner diameter of the conduit to about 8 times the inner diameter of the conduit, or about two-thirds the inner diameter of the conduit to about 6 times the inner diameter of the conduit, or about 1 times the inner diameter of the conduit to about 4 times the inner diameter of the conduit, or the pitch is a length substantially equal to the inner diameter of the conduit, and the pitch is the distance from center to center of adjacent helices or helically wound or coils of the member.

[0132] The foam may be a helical or helically wound or coiled member having a certain pitch angle or a certain pitch (or both), such that when a load or force is applied to the outer surface of the conduit, the foam can be folded or repositioned so that the foam is in a substantially flat configuration when in a second state.

[0133] The foam may be a series of rings, each ring of the series including a hinged interconnect with at least one other ring.

[0134] The hinged interconnect may facilitate distortion or buckling of the foam.

[0135] The foam may be a series of hingedly connected components arranged to provide at least substantially continuous support of the conduit wall at least along a partial length of the conduit including the foam.

[0136] The conduit wall may include at least one foam or an array of foams extending generally longitudinally along the conduit wall or at least along a partial length of the conduit wall including the foam.

[0137] At least one form or array of forms may be formed as part of the conduit wall or may be a flap or hinge provided on or within the conduit wall.

[0138] The flap or hinge may enable folding of the conduit wall.

[0139] The form or array of forms may be a bellows-type mechanism or a bellow-type mechanism, and the mechanism distorts or buckles the conduit from a first state to a second state when a force or load is applied.

[0140] The form may be a hinge formed or integrated as part of the conduit wall or provided on or within the conduit wall.

[0141] A plurality of hinges may be formed as part of the conduit wall.

[0142] These hinges may extend substantially longitudinally along the conduit wall or at least along a partial length of the conduit wall including the hinge.

[0143] In a further aspect, the present disclosure relates to a conduit provided as part of a breathing circuit or used in a respiratory therapy delivery system, the conduit lacking a support structure that would otherwise maintain the conduit in a gas-flowable state, the wall of the conduit defining a lumen therethrough, and the wall having sufficient flexibility to be non-self-supporting.

[0144] The conduit may be maintained in a gas-flow configuration by a positive pressure of the gas provided in the lumen of the conduit.

[0145] In a further aspect, the present disclosure relates to a conduit for supplying or delivering gas to a patient interface, the conduit including a one-way valve, and There is a vent or pressure relief valve for venting or relieving the pressure accumulated in the lumen of the conduit above a preset or predetermined pressure level with respect to the gas flow delivered to the interface and upstream of the one-way valve (e.g., the vent or pressure relief valve can be configured to "open" or relieve pressure when a preset pressure or a predetermined pressure in the conduit is reached). And the one-way valve prevents upstream gas flow from the patient interface.

[0146] Pressure build-up can occur when applying a full-face mask for delivering respiratory therapy at pressure P2 to a patient when the pressure in the conduit containing the vent or pressure relief device and the one-way valve is pressure P1 (where P1 is less than P2), including but not limited to this, and then when applying the respiratory therapy administered to the patient.

[0147] The one-way valve can function to substantially prevent the gas originally supplied to the patient from flowing back from either the patient interface or a subsequent patient interface.

[0148] In a further aspect, the present disclosure relates to a pressure relief device for use with a conduit for delivering pressurized gas from a gas source to a patient, the pressure relief device comprising a first wall and a second wall substantially opposite the first wall, where during normal use the first wall is substantially flush with an adjacent wall of the conduit so that substantially all of the gas from the gas source passes through the conduit, and when a force is applied to the first wall, the first wall moves towards or away from the second wall, providing a passage through which gas can flow out of the conduit into the atmosphere.

[0149] The first wall may be relatively rigid and the second wall may be relatively flexible.

[0150] The pressure relief device may further include a tongue extending from the first wall so as to overlap an adjacent wall of the conduit.

[0151] The first wall is relatively flexible and the second wall is relatively rigid.

[0152] The force may result from the item being pressed against the first wall.

[0153] The force may be the pressure of the gas in the conduit that has reached a threshold pressure.

[0154] In a further aspect, the present disclosure relates to a pressure relief device used with a component of a respiratory assistance system that delivers pressurized gas from a gas source to a patient, the pressure relief device including a biased component engageable with an opening, where in normal use the biased component is biased towards the opening of the component of the respiratory assistance system to substantially seal the opening so that substantially all of the gas from the gas source passes through the conduit, and when the pressure of the gas in the conduit reaches a threshold pressure, the biased member moves away from the opening of the component of the respiratory assistance system, thereby providing a passage through which gas can flow from within the component of the respiratory assistance system to the atmosphere.

[0155] The component of the respiratory assistance system may include a filter.

[0156] The component of the respiratory assistance system may include a conduit.

[0157] The component of the respiratory assistance system may include a chamber.

[0158] In a further aspect, the present disclosure relates to a conduit that delivers pressurized gas from a gas source to a patient, the conduit having an opening, and a pressure relief device used with the conduit, the pressure relief device including a lever mounted within the conduit, the lever having a pivot, an operating portion, and a sealing portion that substantially seals the opening of the conduit so that substantially all of the gas from the gas source passes through the conduit, where when the operating portion is moved, the lever pivots about the pivot and the sealing portion moves away from the opening, thereby providing a passage through which gas can flow from within the conduit to the atmosphere.

[0159] The operating part may be on one side of the pivot, and the sealed part is on the other side of the pivot.

[0160] The operating part may be on one side of the pivot, and the sealed part is on the same side of the pivot.

[0161] In a further aspect, the present disclosure relates to a flow limiting device for use with a conduit for delivering pressurized gas from a gas source to a patient, the flow limiting device including a gate movable in a transverse direction across the conduit from a first position where a substantially first level of gas from the gas source passes through the conduit to a second position where a second level of gas passes.

[0162] The first position may be in a substantially open configuration, and the second position is in a substantially closed configuration. In some configurations, the first gas level is higher than the second gas level.

[0163] The second position may be a completely closed or blocked or interrupted gas flow path, or may be a partially closed or blocked or interrupted gas flow path including, but not limited to, a restricted or throttled gas flow path.

[0164] The flow limiting device may include two gates having complementary engageable features.

[0165] In a further aspect, the present disclosure relates to a component of a respiratory assistance system for delivering pressurized gas from a gas source to a patient, the component being a pressure relief device for use with a component of the respiratory assistance system having an opening, the pressure relief device including a movable part engageable with the opening, where in normal use the movable part is biased to seal the opening of the component of the respiratory assistance system so that substantially all of the gas from the gas source passes through the conduit, and when the pressure of the gas in the conduit reaches a threshold pressure, the movable member opens the opening of the component of the respiratory assistance system, thereby providing a passage through which gas can flow from within the component of the respiratory assistance system to the atmosphere.

[0166] In a further aspect, the present disclosure relates to a combination of a pressure relief device as disclosed herein and a conduit.

[0167] The pressure relief device can be integrally formed with the conduit.

[0168] In a further aspect, the present disclosure relates to a patient interface including one or two side arms extending from a manifold and one or two outlets (such as nose prongs) in or extending from the manifold, wherein one or both of the side arms include a lumen for supplying gas flow from a breathing tube to the manifold and a venting mechanism for venting gas from the lumen to determine a maximum pressure in the user's airway or the patient interface.

[0169] The side arm can include a sealing portion where a seal of a face mask can closely contact the user's face from above, and the vent is positioned outside the sealing range of the face mask on the side arm.

[0170] The sealing portion can include an outer shape that allows the seal of the face mask to closely contact that portion with the user's face.

[0171] The side arm can be configured to withstand external forces so as not to be compressed or crushed during use.

[0172] The side arm can be formed of a relatively rigid material.

[0173] In a further aspect, the present disclosure relates to an item such as a block or mount for use with a patient interface, which item is to be in contact with, or placed in contact with, a patient's face, the item including at least one lumen therethrough for inserting a gas supply conduit or for providing a connection of a gas supply conduit at each end of the lumen (where the gas supplied is in fluid connection with the patient interface), and a venting mechanism for venting gas from the lumen to determine a maximum pressure in the user's airway or in the patient interface.

[0174] The item can include a sealed portion where a seal of a face mask can closely engage with the user's face from above, where the vent is positioned outside of the sealed area of the face mask on the item.

[0175] The sealed portion can include an outer shape that allows a seal of a face mask to closely engage with the user's face at that portion.

[0176] The item can be configured to withstand external forces such that it is not compressed or crushed during use.

[0177] The item can be formed of a relatively rigid material.

[0178] The item can be integrally formed with a side arm of a patient interface such as a cannula.

[0179] The patient interface or item can include a filter device for preventing contamination of a breathing circuit that provides gas flow to the item or interface, the filter device including the venting mechanism.

[0180] In a further aspect, the present disclosure relates to a breathing tube for use with a patient interface, including a window in the wall of the tube and an outer peripheral portion of the window configured to closely engage with the user's face.

[0181] The tube may include a seal surrounding the outer periphery of the window to be in close contact with the user's face.

[0182] The tube may have a relatively flat cross-section compared to a conventional circular cross-section.

[0183] The tube may be formed of an elastic material in the portion of the tube where the window is formed.

[0184] The patient interface may be a nasal cannula.

[0185] The tube may include a membrane covering the window.

[0186] In a further aspect, the present disclosure relates to a respiratory system adapted to provide a respiratory gas flow to a user, which includes a bladder in fluid communication with the lumen of a respiratory gas tube, the bladder being configured to reduce pressure fluctuations within the lumen of the tube and / or reduce a pressure rise of the gas provided to the user.

[0187] The bladder may form or provide a portion of the lumen of the tube.

[0188] The bladder may be a section of the tube where the wall thickness is reduced and / or may be formed of a material that is more elastic than the remaining portion of the tube.

[0189] The bladder may be integrally formed with the portions of the tube extending from each end of the bladder or may be removably attachable to the respiratory tube.

[0190] The bladder may be removably attachable to the respiratory tube, and each end of the bladder is configured to form a respiratory tube assembly including a first length of tube attached to one end of the bladder, the bladder, and a second length of tube attached to the other end of the bladder by being attached to the tube.

[0191] The bladder can provide an indication of the pressure rise within the lumen of the tube.

[0192] The system can include a venting mechanism that, when a pressure rise is reached, operates to vent breathing gas from the lumen of the tube into the bladder.

[0193] The bladder can be configured to accommodate a predetermined volume and pressure of gas reaching a predetermined flow rate and pressure.

[0194] The bladder can be configured to store a volume of gas equal to a flow rate of 70 L / min over a period of 3 - 5 minutes at an operating pressure typical of the desired therapy to be delivered.

[0195] The system can include a relief valve or vent that vents the bladder to the atmosphere when the bladder reaches a predetermined venting pressure.

[0196] In a further aspect, the present disclosure relates to a breathing tube configured to provide a breathing gas flow to a user, the breathing tube including a bladder configured to reduce pressure fluctuations within the lumen of the tube and / or reduce a pressure rise of the gas provided to the user.

[0197] The bladder may form or provide a portion of the lumen of the tube.

[0198] The bladder may be a section of the tube with a reduced wall thickness and / or may be formed of a more elastic material than the remainder of the tube.

[0199] The bladder may be integrally formed with portions of the tube extending from each end of the bladder or may be removably attachable to the breathing tube.

[0200] The breathing tube may be a breathing tube assembly, and each end of the bladder is configured to be attached to the tube to form a breathing tube assembly including a first length of tube attached to one end of the bladder, the bladder, and a second length of tube attached to the other end of the bladder.

[0201] The bladder may provide an indication of an increase in pressure within the lumen of the tube.

[0202] The breathing tube can include a venting mechanism that operates to vent breathing gas from the lumen of the tube into the bladder when an elevated pressure is reached.

[0203] The bladder may be configured to accommodate a predetermined volume and pressure of gas reaching a predetermined flow rate and pressure.

[0204] The bladder may be configured to store a volume of gas equal to a flow rate of 70 L / min for 3 - 5 minutes at an operating pressure typical of the desired therapy to be delivered.

[0205] The system may include a patient interface, a valve, and a vent.

[0206] In a further aspect, the present disclosure relates to a patient interface including a device for blocking flow between an inlet for receiving gas flow and an outlet for delivering gas flow to a patient, and / or a sensing mechanism. The device may be a crushable portion of a conduit between the inlet and the outlet, or a valve between the inlet and the outlet. The sensing mechanism may include a first sensor upstream of the device and a sensor downstream of the device. The patient interface may include a pressure relief valve upstream of the device. The device may be a pressure release device.

[0207] The interface may be a nasal cannula.

[0208] The breathing tube may include a relief valve or vent that vents the bladder to the atmosphere when the bladder reaches a predetermined vent pressure.

[0209] The valve may be a switch, a crushable portion of the conduit, or a one-way valve.

[0210] The vent may be a pressure relief valve.

[0211] The respiratory therapy delivery system may include any one or more of the above.

[0212] The patient interface may be provided in fluid communication with a gas supply conduit or tube, and the conduit or tube includes any one or more of the above.

[0213] A conduit or tube may be provided as part of a respiratory therapy delivery system for supplying gas to the patient interface, and the conduit or tube includes any one or more of the above.

[0214] The system can include any one or more of the above, and the system is provided as part of a respiratory delivery therapy system for a patient undergoing a medical procedure.

[0215] In one embodiment, a system for providing respiratory assistance to a patient is provided, which includes a body portion positionable in an operating position on the patient's face, and at least one nasal prong extending from the body portion, the nasal prong being adapted to direct a gas flow into the nostrils of the patient's nose when the body portion is in the operating position, and a flow controller for selectively controlling the gas flow entering the nostrils of the patient's nose from the nasal prong, the flow controller being adapted to operate to restrict or block the gas flow entering the patient's nostrils from the nasal prong when the pressure of the system exceeds a predetermined value.

[0216] The system is, A pressure sensor or pressure sensing or sampling conduit for measuring or sampling the pressure within the system, and a flow controller adapted to operate in response to the measured or sampled pressure when the measured or sampled pressure exceeds a predetermined value, may be included.

[0217] The pressure sensor can be located on or near a nasal cannula, or on or near a nasal prong, or on a conduit adapted to deliver gas to the nasal cannula, or on a humidifier adapted to humidify the gas flow, or on the flow controller, or the pressure sampling line samples the pressure at any one of these locations.

[0218] The pressure sensor can be located on or near at least one nasal prong.

[0219] The pressure sensor can be located on a conduit adapted to deliver gas to the nasal cannula.

[0220] The flow controller can include a mechanical valve.

[0221] The mechanical valve can be a pressure relief device.

[0222] The system can include at least one processor that controls the flow controller based on the pressure detected by the pressure sensor.

[0223] The pressure relief device can include a valve member that, when pressure acts on the valve member, operates to restrict or block the gas flow entering the patient's nostrils from the nasal prong.

[0224] The pressure relief device can include a cap or housing that houses the valve member outside of the gas lumen of the system.

[0225] The valve member may be biased to a closed position such that a gas flow is provided from the nasal prong into the patient's nostril.

[0226] The valve member may be or may include a piston or a shuttle, and when pressure acts on the piston or shuttle, the pressure relief device operates to restrict or block the gas flow entering the patient's nostril from the nasal prong.

[0227] The predetermined value may be a maximum pressure. The predetermined value may be a variable value.

[0228] The flow controller can be operated to deliver a maximum flow rate while maintaining the pressure below a predetermined value.

[0229] The set flow rate may always be delivered as long as the set pressure is not exceeded, and when exceeded, the system stays below the said pressure by maximizing the flow rate as much as possible.

[0230] The flow controller may be located remotely from the nasal cannula.

[0231] The system may further include a mask that is in situ with the nasal cannula during use.

[0232] The nasal cannula may be an open patient interface.

[0233] The mechanical valve may include a valve member and a spring that biases the valve member to an open position to enable gas flow to be delivered to the patient.

[0234] The valve member may be adapted such that when the pressure in or near the patient's nasal nostril is greater than the force of the spring, the valve member is pushed to the closed position by the flow pressure and no gas flow is delivered to the patient.

[0235] The mechanical valve may have an over-flow outlet.

[0236] The spring tension may be a fixed spring tension. In other embodiments, the spring tension may be a variable spring tension.

[0237] The flow controller may include at least one processor and a user interface.

[0238] The predetermined value may be a fixed value.

[0239] The predetermined value may be a variable value.

[0240] The system may further include an anesthesia mask.

[0241] The nasal cannula may be a non-sealed patient interface.

[0242] The system may further include a second respiratory assistance system for inducing a gas flow into the patient's airway. This gas flow may be a respiratory gas or another gas. The secondary respiratory assistance system may include a mask.

[0243] The flow controller may control the gas flow from one or more gas sources.

[0244] In one embodiment, a method of providing respiratory assistance to a patient is provided, the method comprising: Placing a nasal cannula in an operative position on the patient's face, the nasal cannula having a body portion and at least one nasal prong extending from the body portion; Inducing a gas flow into the patient's nasal nostrils via the nasal prong; Measuring or sampling the pressure of the system; Restricting or blocking the gas flow entering the patient's nasal nostrils from the nasal prong when the measured or sampled pressure exceeds a predetermined value; Allowing the gas flow entering the patient's nasal nostrils from the nasal prong when the pressure at or near the patient's nasal nostrils is below a predetermined value.

[0245] In some embodiments, step iv) includes blocking the gas flow entering the patient's nasal cavity from the nasal prong.

[0246] When the measured pressure exceeds the limit value, the flow can be blocked from entering the system.

[0247] The method may further include inducing a gas flow into the patient's airway using a second respiratory assistance system. The gas flow may be respiratory gas or another gas. The gas may be delivered to the patient via a mask.

[0248] The system may include an overall pressure relief system that can control the overall pressure and one or more flow generators or one or more gas sources (since there may sometimes be no flow generator and only a gas source may exist).

[0249] The pressure sensor can be located on the nasal cannula or in its vicinity, or on the nasal prong or in its vicinity, or on a conduit adapted to deliver gas to the nasal cannula, or on a humidifier adapted to humidify the gas flow, or on a flow controller, or the pressure sampling line samples the pressure at any one of these locations.

[0250] The pressure sensor can be located on the humidifier.

[0251] The pressure sensor can be located on the flow control valve.

[0252] The mechanical valve may be a pressure relief device.

[0253] The system may include a flow controller and a user interface controlled by at least one processor that controls the flow controller based on the pressure detected by the pressure sensor.

[0254] The pressure relief device can include a valve member that, when pressure acts on the valve member, operates to restrict or block the gas flow entering the patient's nostrils from the nasal prong.

[0255] The pressure relief device can include a cap or housing that houses the valve member outside the gas lumen of the system.

[0256] The valve member may be biased to a closed position such that gas flow is provided from the nasal prong into the patient's nostrils.

[0257] The valve member may be or include a piston or shuttle that, when pressure acts on the piston or shuttle, operates to restrict or block the gas flow entering the patient's nostrils from the nasal prong.

[0258] The flow controller can be operated to deliver a maximum flow rate while maintaining the pressure below a predetermined value, and the set pressure is maintained by maximizing the delivered flow rate.

[0259] The set flow rate may always be delivered as long as the set pressure is not exceeded, and when exceeded, the system stays below the said pressure by maximizing the flow rate as much as possible.

[0260] The flow controller can be located remotely from the nasal cannula.

[0261] In a further aspect, a user interface device is disclosed that enables a user to control the gas flow in a respiratory therapy system for delivering high-flow gas to a patient, and the present disclosure relates thereto. This user interface device includes at least one controller operable by the user for controlling the flow rate and / or concentration of two gases through the patient interface and for substantially blocking or reducing the flow rate of at least one of those gases through the patient interface.

[0262] This gas is a high-flow gas. In some configurations, the other of the gases is an anesthetic gas.

[0263] In some configurations, the patient interface is a nasal cannula, where a controller actuated by a user includes a switch positioned on the cannula.

[0264] In a further aspect, the present disclosure relates to a respiratory therapy system including a cannula for delivering high-flow gas to a patient, a mask for delivering gas to the patient, and a pressure sensor associated with the cannula, the system being configured to adjust the flow of high-flow gas through the cannula in response to at least one pressure change detected by the sensor.

[0265] The pressure sensor may be provided on an outer surface of the cannula or on an outer surface of a tube in fluid communication with the cannula.

[0266] The system may be configured to reduce or substantially stop the flow of high-flow gas when the pressure sensor detects a pressure increase.

[0267] The pressure sensor may be configured to detect a pressure increase in response to the mask being placed on the patient, the patient's exhalation, or the actuation of an anesthesia bag.

[0268] The system may further include a valve that partially or substantially blocks the flow of high-flow gas through the cannula in response to the detected pressure increase.

[0269] In a further aspect, the present disclosure relates to a respiratory therapy system including a cannula circuit for delivering high-flow gas to a patient through a cannula, a bag circuit that enables a user to manually deliver gas to the patient by actuating a bag, and a connector connecting the bag circuit to the cannula circuit, the connector including an isolator that substantially prevents high-flow gas from entering the bag circuit.

[0270] The connector can be configured to allow both high-flow gas and gas from the bag circuit to be delivered to the patient through the cannula.

[0271] The connector can be configured to substantially prevent high-flow gas from being delivered to the cannula when the bag circuit is connected to the cannula circuit.

[0272] The isolator can include one or more walls of the connector.

[0273] The cannula can be a nasal cannula having at least one prong receivable in a nostril of the patient, the cannula including one or more inflatable cuffs associated with the one or more prongs to help create a seal in one or more nostrils of the patient.

[0274] The system can be configured to inflate one or more cuffs in response to actuation of the bag.

[0275] In a further aspect, the present disclosure relates to a cannula circuit for delivering high-flow gas to a patient through a cannula; a bag circuit that enables a user to manually deliver gas to the patient by actuating a bag, the bag circuit being in fluid communication with the cannula circuit; and a valve arranged to allow delivery of high-flow gas to the cannula when the bag is not actuated and to allow delivery of gas from the bag circuit to the cannula when the bag is actuated.

[0276] The valve can be arranged to substantially block or reduce the flow of high-flow gas to the cannula in response to actuation of the bag.

[0277] The cannula can be a nasal cannula having at least one prong receivable in a nostril of the patient, the cannula including one or more inflatable cuffs associated with the one or more prongs to help create a seal in one or more nostrils of the patient.

[0278] The system can be configured to inflate one or more cuffs in response to the operation of the bag.

[0279] In a further aspect, the present disclosure relates to a cannula including at least one prong receivable in a patient's nostril, the cannula including one or more inflatable cuffs associated with the one or more prongs to assist in creating a seal in one or more of the patient's nostrils.

[0280] In a further aspect, the present disclosure relates to a respiratory therapy system including a patient interface for delivering gas to a patient; and a processor configured to control the gas flow through the patient interface to deliver gas to the patient at a first flow rate and / or pressure when the patient is breathing spontaneously and to deliver gas to the patient at a second flow rate and / or pressure when the patient is not breathing spontaneously.

[0281] The system can be configured to detect the presence of apnea and to deliver gas at a second flow rate and / or pressure in response to the detection of apnea.

[0282] The system can be configured to detect the presence of apnea based on the cessation of activation of a brain signal, a diaphragm signal, an airway pressure, or a CO2 measurement.

[0283] The first flow rate and / or pressure may include a relatively low flow rate and / or pressure, and the second flow rate and / or pressure may include a relatively high flow rate and / or pressure.

[0284] The processor may be a remote processor.

[0285] In a further aspect, the present disclosure relates to a respiratory therapy system including a patient interface for delivering gas to a patient; a sensor disposed to detect fluctuations in pressure within the patient interface or within a conduit in fluid communication with the patient interface; and a processor configured to adjust the gas flow to the patient interface to deliver gas at a higher flow rate to the patient interface when a decrease in airway pressure is detected.

[0286] The processor may be configured to adjust the gas flow to the patient interface to deliver gas at a higher flow rate to the patient interface when it is determined that a decrease in airway pressure has occurred during and / or after apnea.

[0287] In a further aspect, the present disclosure relates to a patient interface including a cannula for delivering gas to a patient; a connector portion in fluid communication with the cannula, the connector portion configured to removably connect the cannula to a complementary connector portion on a main gas conduit for delivering high flow gas to the cannula; and a secondary conduit in fluid communication with the cannula, the secondary conduit configured to provide fluid communication between the cannula and an alternative gas source.

[0288] The connector portion in fluid communication with the cannula may be configured to seal when the connector portion is detached from the complementary connector portion on the main gas conduit.

[0289] In another aspect, a patient interface is provided that includes a mechanically actuated switch or valve for controlling gas flow from the patient interface to one or more outlets.

[0290] The mechanically actuated switch may be actuated by a user or may be actuated by contacting a component of the respiratory therapy delivery system with the switch, such as contacting a subsequent patient interface with the patient interface including the switch.

[0291] A patient interface including a switch may comprise a vent or pressure relief device that releases pressure buildup resulting from actuation of the switch and partial or complete stoppage or blockage of gas flow to one or more outlets.

[0292] When actuated, the switch may partially block the gas flow path through the patient interface or may completely block the flow path.

[0293] In another aspect, a conduit is provided for use with a patient interface or as part of a respiratory therapy delivery system, the conduit including a mechanically actuated switch or valve that controls the gas flow through and supplied from the conduit to an outlet (e.g., to a patient interface that may be connected to the conduit).

[0294] The mechanically actuated switch may be actuated by a user or may be actuated by contacting a component of the respiratory delivery system with the switch, such as by contacting a subsequent patient interface with the conduit including the switch.

[0295] The conduit including the switch may comprise a vent or pressure relief device that releases pressure buildup resulting from actuation of the switch and partial or complete stoppage or blockage of gas flow from the conduit to an outlet.

[0296] When actuated, the switch may partially block the gas flow path through the conduit or may completely block the flow path.

[0297] The conduit may be a self-supporting conduit (i.e., the conduit is not a crushable conduit).

[0298] In a further aspect, the present disclosure relates to a first patient interface for delivering gas flow to a patient and a second patient interface for delivering gas flow to a patient, and a respiratory therapy system including the same. Here, the sensor is associated with one or more of the following: a first patient interface, a second patient interface, both the first and second patient interfaces, an item associated with the first patient interface, an item associated with the second patient interface, an item associated with both the first and second patient interfaces, an item that will be associated with the patient.

[0299] The first patient interface may include one or a pair of first patient interface outlets for guiding a gas flow to the patient's nose.

[0300] The first patient interface may be of an open interface type.

[0301] The first patient interface may not substantially seal with one or more nostrils of the patient's nose.

[0302] The first patient interface may be a sealed type of interface.

[0303] The first patient interface may substantially seal with one or more nostrils of the patient's nose.

[0304] The first patient interface may deliver a first gas flow to the patient.

[0305] The first gas flow may be a first flow rate and / or pressure.

[0306] The percentage of oxygen in the first gas flow delivered may be 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%.

[0307] The first patient interface may be configured to deliver the gas flow to one or more nostrils of the patient's nose.

[0308] The first patient interface may include one or a pair of nasal prongs.

[0309] One or more prongs may deliver and / or direct the flow of supplied gas to one or more nostrils of the patient's nose.

[0310] The first patient interface may include a facial attachment portion and at least one (preferably a pair of) side arms extending from the facial attachment portion.

[0311] One or more side arms may be configured to assist in positioning the facial attachment portion or the first patient interface relative to the patient.

[0312] The side arms may include a connection system that connects to a connection system worn on the headgear or the face.

[0313] This connection system may be a detachable type or a reusable type of connection system.

[0314] The headgear may include at least one head strap.

[0315] At least one head strap may be divisible or bipartite, or at least a portion of the head strap may be separable along a weakening line or a range preferentially divided or separated.

[0316] At least one head strap may include a single connection point with the respective at least one side arm or each of them.

[0317] The first patient interface may include a detachable manifold portion.

[0318] In a further embodiment, when the detachable manifold portion is attached to the face-wearing portion, it provides a fluid connection between one or a pair of first patient interface outlets and a gas source.

[0319] The manifold portion may be configured to be attachable to the face-wearing portion from either the left or right side of the first patient interface.

[0320] The detachable manifold portion may be the downstream end connector of a gas supply conduit for supplying gas flow to the first patient interface.

[0321] The manifold portion may be a push-fit connection with the face-wearing portion.

[0322] The manifold portion is detachably attached to the face-wearing portion, detachably attached from the connection with the face-wearing portion and configured to pivot or rotate relative to the face-wearing portion from at least one other (preferably second) operably connected arrangement to the first operably connected arrangement.

[0323] With the first operably connected arrangement, the detachable manifold portion and the associated gas supply conduit may extend from the left or right side of the patient during use, or vice versa; and with the second operably connected arrangement, the detachable manifold portion and the associated gas supply conduit may extend from the right or left side of the patient during use, or vice versa.

[0324] The first patient interface may be a nasal cannula.

[0325] The second patient interface may include at least one second patient interface outlet for directing gas flow into the patient's respiratory tract.

[0326] The second patient interface can direct gas flow to the patient's nose, or mouth, or nose and mouth.

[0327] The second patient interface may be of the non-sealed interface type. In a further embodiment, the second patient interface may be a sealed type of interface.

[0328] The second patient interface may be a substantially sealed interface that creates a seal with the patient's face when the second patient interface is in situ.

[0329] The second patient interface can deliver a second gas flow to the patient.

[0330] The second gas flow may be a second pressure.

[0331] The percentage of oxygen in the gas delivered in the second gas flow may be from about 20% to about 100%, or from about 30% to about 100%, or from about 40% to about 100%, or from about 50% to about 100%, or from about 60% to about 100%, or from about 70% to about 100%, or from about 80% to about 100%, or from about 90% to about 100%, or about 100%, or 100%.

[0332] The second patient interface can include a body having a sealed portion that substantially engages or seals with the patient when in situ.

[0333] The sealed portion may be overmolded onto the body or attached to the body in some other way.

[0334] The second patient interface may include a frame to which the body can be attached.

[0335] The patient interface may include an inlet that is connected thereto by a gas supply conduit for supplying gas flow to the second patient interface.

[0336] The second patient interface may be a handheld patient interface.

[0337] The inlet may be a joint.

[0338] The joint may be a ball joint, or a swivel or pivot joint, or an articulating joint, or a joint movable with respect to the body.

[0339] The second patient interface may be a handheld interface.

[0340] The second patient interface can include a connection system for connecting a headgear, which is for supporting or positioning the second patient interface relative to the patient.

[0341] The connection system may be a detachable connection system, and thus the headgear is removable or detachable from the second patient interface during use.

[0342] The second patient interface may be a mask.

[0343] The mask may be a nasal mask, an oral mask, a nasal-oral mask, a full-face mask, a nasal pillow mask, an endotracheal tube, or one of combinations thereof, or any other gas delivery system for providing a second gas flow to the patient.

[0344] The item may be a block or mount that contacts or is to be placed in contact with the patient's face, and the block or mount includes at least one lumen therethrough for inserting a gas supply conduit or for providing a connection of the gas supply conduit at each end of the lumen, where the gas supplied is in fluid connection with the first patient interface.

[0345] The item may be located with at least one gas supply conduit for supplying gas to a first patient interface.

[0346] At least one gas supply conduit may extend through or pass through the body of the item.

[0347] At least one gas supply conduit may be a component that extends through the item and is sealedly engaged by the item.

[0348] A lumen leading to the item may be capable of receiving a gas supply conduit.

[0349] A lumen leading to the item may form part of a fluid passage for delivering gas to a first patient interface.

[0350] The item may include a compressible portion or a portion that can be crushed or deformed under a force or pressure exerted.

[0351] One or more of at least one lumen may be located within a compressible portion or a portion that can be crushed or deformed. The compressible portion may be made of any suitable material such as a polymer or silicone.

[0352] A lumen and / or conduit that may be located within a compressible portion or a portion that can be crushed or deformed may be compressed or deformed so as to block or impede (or prevent) the supply of gas flow to a first patient interface, or partially impede it.

[0353] The item may be an integral part of a side arm of a first patient interface.

[0354] The item may be detachably attachable to a supply conduit to a first patient interface.

[0355] The item may be detachably attachable to a side arm of a first patient interface.

[0356] The item may be an individual component that can be separately positioned or located on a patient, more particularly on the face of the patient.

[0357] The item may be a first patient interface, or a gas conduit in fluid connection with a second patient interface, or a gas conduit in fluid connection with each of the first and second patient interfaces.

[0358] The item may be a patch or pad or wearable device attachable or locatable on a patient for detecting an in-situ co-usage between a first patient interface and a second patient interface on the patient during delivery of gas to the patient, and a signal or output is generated by such detection of co-usage.

[0359] The signal or output may be fed to, or actuate or control, or both actuate and control, one or more of the following system outcomes: Visual alarm or warning Audible alarm or warning, including but not limited to a whistle Tactile or haptic feedback fed to or sent to a wearable electronic device (including but not limited to: a wristwatch, a telephone, a head-mounted display or other clothing incorporating such an electronic device) A flow controller including a flow valve or flow generator, preferably for controlling the gas flow induced to a first patient interface; optionally in addition to, or alternatively to, also including one for controlling the gas flow induced to a second patient interface A pressure regulator or pressure restrictor device, preferably for controlling the pressure of the gas induced to a first patient interface; optionally in addition to, or alternatively to, also including one for controlling the pressure of the gas induced to a second patient interface A diverter for diverting the gas flow to be originally controlled to a vent A microprocessor associated with a flow controller and / or a pressure regulator (or both), A graphical user interface (GUI).

[0360] Control of the flow rate (or pressure) of gas induced in the first patient interface can be effected by the detected in-situ combined signal or output.

[0361] The sensor may use one or any combination of the following in in-situ combined detection: An optical sensor (including infrared, IR) An acoustic (including audible or ultrasonic) sensor A pressure or flow rate sensor, or both, of the gas in the supply conduit supplying gas to the first patient interface, or the second patient interface, or both the first and second patient interfaces, or the pressure or flow rate (or both) of the gas delivered to the patient's respiratory system or a part of the patient's respiratory system, The first patient interface, Or the second patient interface, Or both the first and second interfaces, Or one or more conductivity or resistance electrodes embedded within or placed on a part of an item associated with the first or second or both the first and second patient interfaces, or an item that will be associated with the patient, A radio wave or proximity sensor for detecting in-situ combination, Sensors that are mechanically actuated or triggered, including but not limited to: mechanical switches actuated or triggered by being pressed or placed in contact with another surface, pressure relief valves or pressure sensitive valves, solenoid valves, mechanical valves having a predetermined spring constant (which may, in some cases, be relatively high when the valve is closed and relatively low when the valve is open), and in some cases the pressure relief valve may include a whistle actuated by the release of gas from the valve when moving from a closed position to an open position.

[0362] The sensor may be located on or within the first patient interface, or the second patient interface, or both the first and second patient interfaces, and the sensor detects that the second patient interface is present or placed on or in combination with the first patient interface on or upon the patient. detects that the first patient interface is present or placed on the patient's face and subsequently that the second patient interface is placed or present when used in combination on the patient.

[0363] The sensor may be located on or within the first patient interface.

[0364] The sensor may be located on or within the second patient interface.

[0365] The sensor may detect the second patient interface when it is in situ or "in a predetermined position" on the patient and generate a signal or output.

[0366] The sensor may detect that the second patient interface is placed on the patient.

[0367] The sensor used may be one or more of an optical sensor (including IR), an acoustic sensor (audible or ultrasonic), a mechanically actuated or triggered sensor (e.g., a mechanical switch that actuates upon contact with another object).

[0368] The acoustic detection system can include a transmitter and a receiver. The transmitter transmits a predetermined code (e.g., a modulated acoustic signal), and the receiver receives and detects the code. An acoustic signal may be sent by the transmitter. If there is a second patient interface, the signal is reflected back towards a receiver located in proximity to the transmitter. For example, the transmitter and the receiver may be on or inside the first patient interface, and the signal may be reflected by the second patient interface. Alternatively, the transmitter and the receiver may be on or inside the second patient interface, and the signal may be reflected by the patient's face or the first patient interface.

[0369] The optical detection system can include a transmitter and a receiver. The transmitter transmits a predetermined code (e.g., a specific binary code), and the receiver receives and detects the code. For example, the transmitter and the receiver may be on or inside the first patient interface, and the signal may be reflected by the second patient interface. Alternatively, the transmitter and the receiver may be on or inside the second patient interface, and the signal may be reflected by the patient's face or the second patient interface.

[0370] The sensor can detect in-situ combination, and the gas flow to the first patient interface is controlled. Here, the control of the gas flow to the first patient interface is the interruption or cessation of the gas supply.

[0371] The sensor detects the patient's face, or the first patient interface, or both the patient's face and the first patient interface. By controlling the gas flow to the first patient interface by the sensor, or generating a signal or output, the gas flow to the first patient interface is controlled or adjusted, or an alarm or warning is generated.

[0372] The sensor can be selected or tuned to detect components located on or embedded in the first or second patient interface, or located on or embedded in each of the first and second patient interfaces.

[0373] The sensor can be selected or tuned to avoid spurious false positive detections.

[0374] The sensor can be located on or embedded in an item which is a block or mount that contacts or is to be placed in contact with (or is attachable or wearable on) the patient's face and which includes at least one lumen therethrough for inserting a gas supply conduit or for providing a connection of a gas supply conduit at each end of the lumen, where the gas supplied is in fluid connection with the first patient interface.

[0375] The second patient interface may be placed in contact with the item, and the sensor is located on or embedded in the item to detect the presence of the second patient interface and generate a signal or output.

[0376] The sensor may be at least one pair of electrodes that generate a signal or output based on a change in permittivity or capacitance between the electrodes, and this signal or output is used to feed any one or more of the system outcomes as defined above, or it is actuated or controlled (or actuated and controlled).

[0377] The sensor may be a mechanical switch that is actuated by the second patient interface being placed in contact with the sensor and generates a signal or output.

[0378] The mechanical switch can include an operable protrusion or prong extending from the item, and this protrusion or prong extends from the item at a location where it will contact the second patient interface when the second patient interface is provided in an operative configuration with the patient.

[0379] The operable protrusion or prong can be a pushable button, which activates to generate a signal or output when pressed.

[0380] The mechanical switch can include a strain gauge, and the strain gauge generates a signal or output when a predetermined amount of strain is detected, and this predetermined amount of strain indicates that the second patient interface is placed in contact with the item when the second patient interface is in an operative configuration with the patient.

[0381] The item can include an optically transmissive portion (such as, but not limited to, an optically clear window section), where the optical sensor is located within this transmissive portion, and the optical sensor optically detects the presence of the second patient interface when placed in substantial contact with at least a portion of that portion.

[0382] Before the second patient interface is present or placed substantially on the optically transmissive portion, the detection system can detect total internal reflection; and when the second patient interface is present or placed on the optically transmissive portion, the detection system can detect attenuated internal reflection.

[0383] The sensor can be a pressure-sensitive switch or a pressure detection system that detects or senses an increase in pressure when the second patient interface is placed in contact with the item.

[0384] A pressure-sensitive switch or pressure detection system can include a pressure sensor within a chamber filled with gas within an item, and when provided for use with a patient, a flexible or pressure-sensitive membrane should be placed as a barrier or outer surface against a second patient interface, and when the second patient interface is placed on the barrier or outer surface, a change in pressure occurs within the chamber.

[0385] A change in pressure within the chamber is detected by the sensor, and a signal or output can be generated indicating the presence of the second patient interface in combination with the item.

[0386] A pressure-sensitive switch or pressure detection system can include a pressure sensor within a seal of the second patient interface, and when the second patient interface is placed on a patient, a change in pressure is caused within the seal, which is detected by the sensor, and a signal or output is generated indicating the presence of the second patient interface on the patient.

[0387] The sensor may be located on or embedded within the first patient interface.

[0388] The sensor can use one or more of an acoustic (audible or ultrasonic) detection system, an optical beam detection system (including IR), a temperature detection system.

[0389] The sensor may be a temperature detection system that detects a change in temperature, particularly when a predetermined temperature or temperature range is associated with the temperature of the patient or their skin, and detects it when the first patient interface is in a predetermined or operable position on the patient.

[0390] When the temperature detection system is activated, other sensors can be made operable. This can prevent other sensors from operating when the first patient interface is not in a predetermined or operable position on the patient.

[0391] An item associated with the first patient interface, or the second patient interface, or both the first and second patient interfaces may be a gas supply conduit.

[0392] A sensor may be associated with the item.

[0393] The sensor associated with the item may be an acoustic type detection system.

[0394] The sensor may detect a change in a parameter or characteristic of the item that is indicative of an increase in pressure or a decrease in gas flow within or through the item.

[0395] The parameter or characteristic may be a change in the shape of the gas supply conduit caused by an external force or pressure, such as an increase in pressure within the conduit, a decrease in gas flow through the conduit, a force or pressure exerted on the conduit from the second patient interface (whether the force or pressure is applied directly or indirectly), or a change in the shape of the conduit due to a change in the shape of the conduit caused by an external force or pressure (such as a change in the shape of the conduit due to a change in the shape of the conduit caused by an external force or pressure).

[0396] The sensor may include an acoustic signal transmitter and an acoustic signal receiver, and the transmitted acoustic signal is modified or altered by a change in the shape of the gas supply conduit indicating an increase in pressure or a decrease in gas flow within or through the conduit.

[0397] The sensor may detect a reflected signal (e.g., due to closure of the conduit or a change or deviation in the shape of the conduit outside a predetermined operating range), or a change in resonance (e.g., due to the formation of a standing wave within the conduit when the conduit is closed or a change or deviation in the shape of the conduit outside a predetermined operating range).

[0398] In a further aspect, the present disclosure a controller, a flow generator, a sensor system, such as a pressure sensor system, a flow sensor system, and / or a motor speed sensor system, A first patient interface, a second patient interface, and relates to a respiratory system.

[0399] The controller may be adapted to detect a change in pressure, a change in flow rate, or a change in the motor speed of a mechanical blower, and in response to the detection of the change, the controller actuates or controls (or actuates and controls) any one or more of the "system outcomes" as defined above.

[0400] The respiratory system can include a humidifier and a chamber having a chamber inlet and a chamber outlet, and the pressure sensor system is positioned at the chamber outlet.

[0401] The system may include a flow sensor at the chamber inlet and / or the chamber outlet. The flow sensor may be a heated-bead type sensor. Alternatively, the flow sensor may be an ultrasonic flow sensor integrated with the controller.

[0402] In a further aspect, the present disclosure a nasal cannula for delivering a gas flow to a patient, a mask for delivering a gas flow to a patient, and relates to a respiratory therapy system.

[0403] The sensor may be associated with one or more of the following: a nasal cannula, a mask, both the cannula and the mask, an item associated with the nasal cannula, an item associated with the mask, an item associated with both the nasal cannula and the mask, an item that will be associated with the patient.

[0404] The sensor can detect the in-situ co-use of the nasal cannula and the mask on the patient during gas delivery to the patient, and a signal can be generated by the detection of the co-use.

[0405] In a further aspect, the present disclosure relates to a patient interface including a sensor associated with the interface, the sensor being for determining a dual operational application of a pair of patient interfaces to a patient's airway.

[0406] The patient interface may be a nasal cannula.

[0407] The patient interface may be a mask.

[0408] The mask may be one of a nasal mask, an oral mask, a nasal-oral mask, a full-face mask, a nasal pillow mask, an endotracheal tube, or a combination thereof, or any other gas delivery system that provides a second gas flow to the patient.

[0409] The first patient interface of the pair of interfaces may be a nasal cannula.

[0410] The second patient interface of the pair of interfaces may be a mask.

[0411] The sensor may be associated with either the first or second patient interface, or both the first and second patient interfaces.

[0412] The sensor may be associated with an item that will be provided for operative use in combination with either the first or second patient interface, or both the first and second patient interfaces.

[0413] In a further aspect, the present disclosure is a body including an opening or port that enables communication of gas to and / or from a gas supply or source and / or to the internal volume of the interface (the internal volume being defined during use by the inside of the body and the user's face), and A face seal provided to create or form a seal between a user interface and the user's face and / or a spacer component provided on the user's face so as to form a sealed internal volume. Regarding a user interface for supplying gas to a user's airway, Here, the face seal and / or spacer component thus provided on the user's face is adapted to create or form a seal between the user interface and the user's face and / or the spacer component thus provided on the face, and is adapted or configured to facilitate penetration into the sealed internal volume of the gas conduit extending between the body and the user's face.

[0414] The face seal includes one or more adapted sites or portions adapted to facilitate penetration into the sealed internal volume of the gas conduit while maintaining a seal between the user interface and the user's face.

[0415] The seal can be located or provided substantially at, around, or adjacent to the periphery or outer circumference of the body.

[0416] The one or more adapted sites or portions include cutouts or suitably conforming portions in the face seal or the face seal and the body.

[0417] The cutout or suitably conforming portion can be adapted to conform to the outer shape of the gas conduit or spacer component.

[0418] The spacer component can include a channel or groove or passage for receiving a portion of the gas conduit and a sealing surface on which the face seal forms a seal with the user's face.

[0419] The spacer component may be a sleeve that encloses or at least partially surrounds a portion of the gas conduit.

[0420] The spacer component may include a first portion and a second portion adapted to receive or clamp, accommodate or hold a gas conduit between the two portions.

[0421] The first and second portions may be hinged or pivotally joined on one side to receive or clamp, accommodate or hold a gas conduit between these two portions and may be openable from the other side.

[0422] The first and / or second portion includes a groove, channel or passage adapted or assisting to position the conduit between the first portion and the second portion.

[0423] The interface may also include a coupling mechanism for coupling the spacer component to the interface.

[0424] The coupling mechanism can include a protrusion and a complementary groove, where the protrusion is provided on one of the face seal and the spacer component, and the groove is provided on the other of the face seal and the spacer component.

[0425] The spacer component can be capable of allowing the gas conduit to be partially crushed when the user wears the interface, and the spacer component is adapted to be crushed under the force provided by the face seal on the user's face.

[0426] In a further aspect, the present disclosure relates to a spacer component used in a gas supply system for conveying breathable gas to and / or from a user via any one of the above user interfaces, and a gas conduit for delivering breathable gas to and / or from a user via a separate gas supply system or gas source, the spacer component being positioned on the user's face and adapted to create or form a seal between the user interface and the user's face and configured and adapted to facilitate penetration of the gas conduit extending between the face seal and the user's face into a sealed internal volume.

[0427] The spacer component may be provided along a portion of the length of the conduit, preferably along the length of the conduit that engages or contacts the face seal of the user interface.

[0428] The sleeve may include a first portion and a second portion adapted to receive, clamp, accommodate or hold a gas conduit between the two portions.

[0429] These two portions may be pivotally or hingedly joined along one side to receive a conduit between the two portions and may be openable along the other side.

[0430] The spacer component may be snap-fastened or clip-fastened removably to the conduit or may be removably attached in other ways.

[0431] The spacer component may include a channel or groove or passage for receiving the conduit.

[0432] The spacer component can allow the gas conduit to be partially crushed when the user wears the interface, and the spacer component can be adapted to be crushed under the force provided by the face seal on the user's face.

[0433] In at least one of the embodiments disclosed herein, a system for providing respiratory assistance to a patient, said system comprising a nasal cannula for delivering gas to the patient's nostrils via a gas conduit, and a user interface according to any one of the above aspects.

[0434] The system is configured to deliver a general anesthetic to the user via the user interface and, separately from or in addition to that, also deliver high-flow oxygen to the user's nostrils via the nasal cannula.

[0435] In a further aspect, the present disclosure relates to a system for providing respiratory assistance to a patient, including the combined use of an oronasal mask and a nasal cannula assembly, wherein each of the mask and the nasal cannula assembly is provided with a separate gas flow supply from one or more sources, and the nasal cannula is positionable on the user independently of the mask.

[0436] As used herein and in the claims, the term "comprising" means "consisting at least in part of". When interpreting each statement in this specification and the claims that includes the term "comprising", features other than the thing or things preceded by this term may also be present. Related terms such as "comprise" and "comprises" should be interpreted in the same way.

[0437] References to numerical ranges disclosed herein (e.g., 1 to 10) also include references to any rational number within the range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10) and also any range of rational numbers within the range (e.g., 2 to 8, 1.5 to 5.5, and 3.1 to 4.7), and thus all sub-ranges of all ranges explicitly disclosed herein are intended to be explicitly disclosed by this specification. These are merely examples of what is specifically intended, and all possible combinations of numbers between the recited minimum and maximum values should be considered to be equally explicitly recited herein.

[0438] As used herein, the term "and / or" means "and" or "or", or both.

[0439] As used herein, "(s)" following a noun means the plural and / or singular form of that noun.

[0440] Those skilled in the art to which the present invention pertains will envision many structural changes, as well as a wide variety of embodiments and applications, without departing from the scope of the present invention as defined in the appended claims. The present disclosure and the description herein are merely illustrative and are not intended to be limiting in any sense.

[0441] The present disclosure is as described above and also assumes its configuration, which is provided only as an example hereinafter.

[0442] By referring to the following figures, specific embodiments and their variations will become apparent to those skilled in the art from the detailed description herein.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0444] The foregoing descriptions of the various embodiments and disclosures herein include their preferred forms. Modifications may be made thereto without departing from the scope of the present disclosure.

[0445] FIG. 1 shows a respiratory therapy system 100. The respiratory therapy system 100 includes a flow generator 102. The flow generator 102 is configured to generate a gas flow that flows through the respiratory therapy system 100. The flow generator 102 sends air to a humidifier 104. The humidifier 104 is configured to heat and humidify the gas flow generated by the flow generator 102. In some configurations, the flow generator 102 includes a blower adapted to receive gas from the external environment of the respiratory therapy system 100 and to propel it into the respiratory therapy system 100. In some configurations, the flow generator 102 may include some other gas generating means. For example, in some configurations, the flow generator 102 may include a source available from a hospital gas outlet (e.g., oxygen or air), or one or more containers of compressed air and / or another gas and one or more valve mechanisms adapted to control the rate at which the gas exits the one or more containers. As another example, in some configurations, the flow generator 102 may include an oxygen concentrator. In some configurations, the flow generator 102 may be adapted to deliver high-flow therapy.

[0446] According to the various configurations and embodiments described herein, the flow rate of the gas supplied or provided to the interface or through the system, for example through a flow path, although not limited, may include a flow rate of at least about 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150 L / min, or more, and the useful range can be selected between any of these values (e.g., about 40 to about 80, about 50 to about 80, about 60 to about 80, about 70 to about 100 L / min, about 70 to 80 L / min). In some embodiments, a flow rate greater than about 15 L / min, particularly, although not limited, a flow rate of about 60 to 70 L / min, can be used in such a configuration or embodiment. "High flow" or "high flow therapy" can refer to the delivery of gas to a patient at a flow rate of about 5 or 10 L / min to about 100 L / min, or about 15 L / min to about 95 L / min, or about 20 L / min to about 90 L / min, or about 25 L / min to about 85 L / min, or about 30 L / min to about 80 L / min, or about 35 L / min to about 75 L / min, or about 40 L / min to about 70 L / min, or about 45 L / min to about 65 L / min, or about 50 L / min to about 60 L / min.

[0447] The gas to be delivered may contain a certain percentage of oxygen. In some configurations, the percentage of oxygen in the gas to be delivered may be 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%.

[0448] High flow therapy has been found to be effective in achieving or exceeding the patient's normal maximum inspiratory demand and increasing the patient's oxygenation and / or reducing the work of breathing. In addition, high flow therapy can produce a flush effect in the nasopharynx, and the anatomic dead space of the upper airway is flushed by a high volume of inflowing gas flow. This results in a reservoir of fresh gas available with each breath, while minimizing rebreathing of carbon dioxide, nitrogen, etc.

[0449] In the embodiments or configurations described herein, a relatively high gas delivery flow rate can be used, so the gas supplied or provided to the user or patient can be delivered to various parts of the user's or patient's airway.

[0450] Such a relatively high flow rate of gas can be useful for delivering the supplied gas to the user's airway or various parts of the user's airway. For example, such a flow rate may enable delivering such gas to the upper airway or lower airway regions. The upper airway region typically includes the nasal cavity, pharynx, and larynx, while the lower airway region typically includes the trachea, primary bronchi, and lungs.

[0451] FIG. 11 shows a typical human airway and includes arrows indicating how a relatively high flow rate of gas supplied to the user can be utilized to more effectively push or drive the supplied gas further or deeper into the user's airway compared to when the person is in a normal or typical self-driven breathing state or when the patient's breathing drive is reduced.

[0452] Respiratory therapy system 100 includes a housing 106 that at least partially houses both a flow generator 102 and a humidifier 104 (e.g., respiratory therapy system 100 may include an integrated flow generator / humidifier). In other configurations, flow generator 102 and humidifier 104 may have separate housings. Hardware controller 108 is shown to be in electronic communication with flow generator 102 and humidifier 104, but in some configurations, hardware controller 108 may communicate with only flow generator 102 or humidifier 104. Hardware controller 108 may include a microcontroller or some other architecture configured to direct the operation of controllable components of respiratory therapy system 100, including but not limited to flow generator 102 and / or humidifier 104. Input / output module 110 is shown to be in electronic communication with controller 108. Input / output module 110 is configured to facilitate a user's interaction with controller 108 to control controllable components of respiratory therapy system 100, including but not limited to flow generator 102 and / or humidifier 104, and / or to view data regarding the operation of respiratory therapy system 100 and / or its components. Input / output module 110 may include, for example, one or more buttons, knobs, dials, switches, levers, touchscreens, speakers, displays, and / or other input or output peripherals that a user may use to view data and / or input commands to control components of respiratory therapy system 100.

[0453] As further shown in FIG. 1, an auxiliary gas source 124 can be used to add one or more auxiliary gases to the gas flowing through the respiratory therapy system 100. The one or more auxiliary gases are combined with the gas flow generated by the flow generator 102. The auxiliary gas source 124 can be configured to deliver one or more auxiliary gases including, but not limited to, air, oxygen (O2), carbon dioxide (CO2), nitrogen (N2), nitrous oxide (NO), and / or heliox (a mixture of helium and oxygen). The auxiliary gas source 124 may deliver one or more auxiliary gases to a location upstream of the flow generator 102 through a first auxiliary gas lumen 128, and / or may deliver one or more auxiliary gases to a location downstream of the flow generator 102 and / or upstream of the humidifier 104 through a second auxiliary gas conduit 132. One or more auxiliary flow valves 126, 130 can be used to control the rate at which one or more auxiliary gases can flow from the auxiliary gas source 124 through the first and / or second auxiliary gas conduits 128, 132. One or more of the auxiliary flow valves 126, 130 may be in electronic communication with the controller 108, and thus the controller 108 can control the operation and / or state of one or more of the auxiliary flow valves 126, 130. In other configurations, the auxiliary gas source 124 may be configured to add one or more auxiliary gases downstream of the humidifier 104.

[0454] As shown in FIG. 1, a conduit 112 extending from the humidifier 104 connects the humidifier 104 to the patient interface 200. The conduit 112 may include a conduit heater 114 adapted to heat the gas passing through the conduit 112. In other configurations, the conduit heater 114 may not be present. Although the patient interface 200 is shown as a nasal cannula, it should be understood that in some configurations other patient interfaces may be suitable. For example, in some configurations, the patient interface 200 can include a closed or non-closed interface and can include a nasal mask, an oral mask, a nasal-oral mask, a full-face mask, a nasal pillow mask, a nasal cannula, an endotracheal tube, a tracheostomy tube, a combination of the above, or some other gas delivery system. In a preferred embodiment, the patient interface 200 is a non-closed interface such as a nasal cannula, which allows for gas exchange with the environment. For example, a non-closed cannula can remove and / or expel carbon dioxide from the patient's airway while the patient is receiving flow therapy from the system 100. Further, in a preferred embodiment, the patient interface 200 is in the form of a nasal interface so that the system does not interfere with other oral airway devices and / or apparatuses, such as the tracheal tube in an intubation procedure. Thus, the patient can continue to receive flow therapy throughout the intubation procedure.

[0455] As shown, in some configurations, the patient interface 200 may also include a gas detection module 120 adapted to measure the characteristics of the gas passing through the patient interface 200. In other configurations, the gas detection module 120 may be positioned and adapted to measure the characteristics of the gas in another part of or in the vicinity of the respiratory therapy system 100. The gas detection module 120 may include one or more sensors adapted to measure various characteristics of the gas, including but not limited to pressure, flow rate, temperature, absolute humidity, relative humidity, enthalpy, gas composition, oxygen concentration, carbon dioxide concentration, and / or nitrogen concentration. The gas characteristics determined by the gas detection module 120 may be utilized in several ways, including but not limited to closed-loop control of gas parameters. For example, in some configurations, the instantaneous flow rate may be determined using the flow rate data taken by the gas detection module 120, and in turn, it may be used to determine the patient's respiratory cycle, and the delivery of the flow synchronized with each part of the respiratory cycle may be facilitated. The gas detection module 120 may communicate with the controller 108 via a first transmission line 122. In some configurations, the first transmission line 122 may include a data communication connection adapted to transmit data signals. The data communication connection may include a wired data communication connection such as a data cable, or a wireless data communication connection such as Wi-Fi or Bluetooth®. In some configurations, both power and data may be communicated on the same first transmission line 122. For example, the gas detection module 120 may include a modulator that may enable the data signal to be “overlaid” on the power signal. The data signal may be superimposed on the power signal, and this combined signal may be demodulated by the controller 108 before use. In other configurations, the first transmission line 122 may include a pneumatic communication connection adapted to deliver an analytical gas flow in a part of the respiratory therapy system 100.

[0456] In addition, as shown, a physiological sensor module 121 may be present. The physiological sensor module 121 may be configured to detect various characteristics of a patient or the patient's health, including but not limited to heart rate, EEG signals, EKG / ECG signals, inertial sensors attached to the patient (e.g., on the chest) for detecting movement, blood oxygen concentration (e.g., by a pulse oximeter), blood CO2 concentration, transcutaneous CO2 (TcCO2) and / or blood glucose. Similarly, the physiological sensor module 121 may communicate with the controller 108 via a second transmission line 123. The second transmission line 123 can include a wired or wireless data communication connection, similar to the first transmission line 122, and power and data can be communicated similarly. The physiological sensor module 121 may be used, for example, to determine a patient's blood oxygen saturation.

[0457] Figure 2 shows a patient P wearing a patient interface 200, such as the patient interface 200 of the respiratory system of FIG. 1. In an exemplary non-limiting configuration, the patient interface 200 is a nasal cannula. The patient interface 200 includes a first gas lumen 202 defined by a tubular wall. The first gas lumen 202 is adapted to receive gas from the respiratory therapy system 100 (e.g., via the conduit 112 shown in FIG. 1) and carry that gas to the patient P. The exemplary first gas lumen 202 is at least partially defined by a wall through which gas can be carried on the inside. The first gas lumen 202 may include a reinforcing element 203 adapted to reinforce the first gas lumen and / or add rigidity thereto to prevent deformation or crushing of the first gas lumen 202 caused by forces applied to the first gas lumen 202. The reinforcing element 203 can include a number of structures, including but not limited to plastic or metal reinforcing beads within or on the wall of the first gas lumen 202.

[0458] The first gas lumen 202 is in pneumatic communication with the flow manifold 206. The flow manifold 206 receives gas from the first gas lumen 202 and delivers it to one or more transnasal delivery elements 208 (e.g., prongs). The one or more transnasal delivery elements 208 extend outwardly from the flow manifold 206. The one or more transnasal delivery elements 208 are adapted to be positioned in a non-sealing manner within one or more nostrils of the patient P. As shown, the patient interface 200 includes two transnasal delivery elements 208 adapted to be positioned one in each of the patient's nostrils. Each transnasal delivery element 208 may have a shape or angle such that it extends inwardly toward the nasal septum of the patient. Alternatively, the first patient interface 200 may be a sealed nasal interface.

[0459] In addition, each transnasal delivery element may have a shape or angle such that the tip of each transnasal delivery element faces toward the back of the head of the patient P during use. In the embodiment shown in FIG. 2, the flow manifold 206 receives flow from one lateral side of the flow manifold 206 (e.g., with respect to a virtual vertical plane bisecting the face of the patient P) and delivers the flow to each of the transnasal delivery elements 208. In other configurations, the patient interface 200 may include more (e.g., three or four) or fewer (e.g., one) transnasal delivery elements 208.

[0460] In other configurations, each nasal delivery element 208 can have different characteristics. For example, one of a pair of nasal delivery elements 208 may be relatively long and the other nasal delivery element 208 may be relatively short. In some configurations, the flow manifold 206 may be configured to receive flow from two lateral sides of the flow manifold 206 (e.g., not only from the "left" of the flow manifold 206 as seen in FIG. 2, but also from the "left" and "right" of the flow manifold 206). In some such configurations, multiple gas lumens may be used to provide pneumatic communication between the flow manifold 206 and the respiratory therapy system 100. In some configurations, the flow manifold 206 may be configured to receive flow from non-lateral sides of the flow manifold 206 (e.g., from the "bottom" or "top" of the flow manifold 206).

[0461] The patient interface may further include a mount and / or support, such as a cheek support 210, for attaching and / or supporting the gas lumen 202 to the patient's face. Alternatively, the patient interface may be held in place by one or more head straps or headgear.

[0462] Furthermore, the first gas lumen 202 may include a first portion 204 configured to transition from a first configuration in which a first level of gas can pass through the first portion 204 to a second configuration in which a second level of gas can pass through the first portion 204. This feature will be described in more detail below.

[0463] FIG. 3 shows a non-limiting exemplary embodiment of a patient P wearing the patient interface 200 (first patient interface) as shown in FIG. 2 under a face mask 300 assembly (second patient interface). FIG. 3 schematically shows the face mask as a transparent structure to illustrate the underlying patient interface 200.

[0464] The benefits of the system can be found in selectively delivering different therapies to patients using different patient interfaces. The systems and devices as described find particular application in emergency resuscitation, intubation of patients receiving high flow therapy, otolaryngology (ENT) surgery, assisting in the conditioning of patients in the preoperative state prior to administration of anesthesia, and in the post-extubation recovery period.

[0465] The face mask assembly 300 is used as or with a second respiratory assistance subsystem and / or to deliver to the patient one or more substances other than those delivered by the cannula 200, such as an anesthetic or oxygen, or the same substance but at different flow and / or pressure levels. Thus, in the embodiment shown in FIG. 3, it is possible to deliver gas from multiple sources via two respiratory assistance subsystems. Additionally, according to this configuration, it may be possible to leave the patient interface 200 on the patient throughout the surgical procedure and / or until entering the recovery period (regardless of whether the patient continues to receive flow therapy via the patient interface 200 during the procedure).

[0466] In the illustrated embodiment, the face mask assembly 300 includes a full face mask 302 configured to cover both the patient's nose and mouth. In other configurations, the face mask 300 may be a nasal mask or a mouth mask placed on the patient interface 200 to cover only the patient's nasal region or only the patient's mouth.

[0467] As shown, the face mask 302 includes a seal region 304 adapted to closely conform to the patient's face. The face mask assembly 300 is connected to a second gas source, for example via a filter element 400, which supplies one or more other gases to the patient via the face mask. That is, the second gas source is preferably different from the gas supply source to the patient interface 200 (e.g., the auxiliary gas source 124 / flow generator 102).

[0468] In a preferred embodiment, the face mask assembly 300 is connected to a separate gas source or a separate breathing assistance device. For example, the breathing assistance can be a ventilator or a CPAP or a high flow therapy device or a manual resuscitator (e.g., a handheld face mask with a bag).

[0469] Alternatively, the mask assembly 300 may be connected to an anesthesia device and can deliver anesthetic gas, or air, or oxygen, or a combination of gases via the mask 302.

[0470] In the embodiment shown in FIG. 3, it is possible to deliver gas from a plurality of sources in at least two different breathing assistance modes, and furthermore, a physician, clinician or medical professional can quickly and easily change the type of breathing assistance mode.

[0471] In one particular application, a patient being prepared for anesthesia can be pre-oxygenated by delivering high-flow oxygen via a nasal cannula. Depending on the situation, an anesthesiologist managing the patient's sedation may attempt to switch between delivering gas flow from one patient interface (e.g., a nasal cannula) and delivering gas flow from another patient interface, such as via a face mask. Delivering gas from the cannula in combination with the gas from the mask, or even delivering gas from the cannula while the mask is sealed on the cannula, can cause a pressure increase, which can damage the patient's lungs. The anesthesiologist may also use a bag-valve mask to oxygenate the patient and, in some cases, may feel that it is more comfortable to use the bag-valve mask when the patient's vital signs are deteriorating. In such situations, as described above, the flow through the cannula and the pulsed gas flow from the bag-valve mask can cause overpressure in the lungs and also cause lung damage. In certain situations, medical professionals may attempt to switch between different respiratory systems or assistive modes. In a first mode, respiratory assistance may be provided by a first respiratory assistance system (e.g., via patient interface 200), and in a second mode, after the switch is made, respiratory assistance may be provided by a second respiratory assistance system (e.g., via patient interface 300) instead of the assistance from the first system. For example, since additional flow from high-flow can also change the expected behavior of the anesthesia circuit, it may be advantageous to be able to turn off the additional flow from the first respiratory system.

[0472] In some configurations, the switching between two respiratory assistance modes or subsystems may be facilitated by the structure of a first gas lumen (first conduit 202), which has a first portion 204 configured to transition from a first configuration in which a first level of gas can pass through the first portion 204 to a second configuration in which a second level of gas can pass through the first portion 204.

[0473] Preferably, the first portion 204 is more crushable than other portions of the lumen 202, or is otherwise configured to better accommodate a change in gas flow through the first portion 204 (and thus reduce the gas flow reaching the patient through the lumen).

[0474] In other embodiments, the first configuration or first state is a substantially open configuration, and the second configuration or second state is a substantially closed configuration. That is, the lumen 202 is configured to be more crushable, more deformable than other portions of the lumen 202, or otherwise accommodate a complete blockage of flow at the first portion 204. FIG. 4 shows an example of this configuration, where the lumen of the first portion 204 (e.g., lumen 202 of FIG. 3) is substantially closed by the seal 304 of the face mask 302. In such embodiments, the first portion of the first gas lumen (i.e., the more crushable or deformable section) must be longer than the width of the section of the seal of the face mask that lies over the first portion of the first gas lumen. This ensures that the seal of the face mask does not lie over a non-crushable section of the first gas lumen. For example, the first portion may extend from 35 mm or less from the center of the user's nose to at least 50 mm from the center of the user's nose, and the first portion has a length of at least 15 mm. In some embodiments, the length of the first portion may be at least 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm or more.

[0475] The first portion 204 may be deployed between the first and second configurations based on the force applied to the outer wall of the first portion 204, or the relative level of the force received by its inner wall. For example, as shown in FIG. 3, this force may be applied by the seal 304 of the face mask 302. In this example, the first portion 204 is configured to be positioned under the seal 304 of the face mask 302. Alternatively, this force may be applied to the first portion 204 by other means, such as a clamp (not shown). In some embodiments, when the seal of the face mask acts on the first portion of the gas lumen, a seal or at least a partial seal is formed between the first patient interface and the flow generator by the first portion. Additionally, the seal of the face mask covers the first portion of the gas lumen to form a seal or at least a partial seal. Thus, the switching between respiratory assistance therapies is achieved simply by applying a mask to the patient's face, where the seal of the mask (partially or completely) crushes the first portion of the gas lumen, thereby "turning off" or reducing the therapy supplied by the first interface, and also providing a seal between the face mask and the outer surface of the first portion, so that the therapy can be provided solely or at least primarily by the mask. In some embodiments, when the mask is removed from the patient's face, it is possible to resume the therapy supplied by the first interface.

[0476] According to FIGS. 12A - 15B, the following disclosure relates to a conduit, whether it is a conduit as part of a conduit, or the entire conduit, or a conduit provided as an interconnection between other conduits or components associated with a patient interface such as a nasal cannula or a mask. These figures can be in a first configuration or a first state where the lumen or gas flow path of the conduit remains open or the gas flow capacity is maintained, but when a force or load is applied, it deforms or distorts or buckles into a second configuration or a second state where the lumen or gas flow path is substantially closed or blocked or the gas flow therethrough is obstructed. Further, in the second configuration or state, the crushable type of conduit provides a crushed form that can help ensure that the seal of the mask can form a seal or at least a partial seal on the conduit with the patient's face.

[0477] The form or array of forms in FIGS. 12A - 15B may be independent of the conduit wall or the inner wall surface. That is, this one or more forms are not attached or connected to the conduit wall or its inner surface. Alternatively, the form or array of forms in FIGS. 12A - 15B may be attached along only a portion of the inner circumference (lateral perimeter) of the conduit to the conduit wall. This allows one or more forms to move independently of or relative to the conduit wall, enabling it to reconfigure from the first state to the second state by allowing its distortion or buckling or other change in shape or arrangement.

[0478] FIGS. 12A - 15B provide a cross - sectional side view (or a view with the conduit wall made transparent) of a conduit 400 used as part of a respiratory therapy delivery system (such as, but not limited to, the system of FIG. 1), or at least a partial length of the conduit 400. The conduit or the partial length of the conduit 400 includes at least one form or array of forms 401 that supports or forms a part of the conduit wall 402. The inner surface 403 of the conduit wall 402 forms the lumen or gas flow path 404 of the conduit 400.

[0479] At least one form or array of forms 401 is biased to preferentially maintain a lumen or gas flow path in a first state (e.g., as shown by FIGS. 12A, 13A, 13B, 14A, 15A). The first state is a substantially open or substantially uncrushed conduit wall state, which provides an unobstructed gas flow to another component associated with a respiratory therapy delivery system such as a patient interface, or to another section of the conduit.

[0480] A partial length of a conduit or conduit 400 that includes at least one form or array of forms 401 is configured to distort or buckle from the first state to a second state (e.g., as shown by FIGS. 12B, 14B, 15B) in response to a force or load 405 applied to an outer surface 406 of a conduit wall 402 that includes the at least one form or array of forms 401.

[0481] The second state is a configuration or state having a substantially closed or substantially crushed conduit wall state, or a configuration or state where the lumen or gas flow path 404 is substantially closed, blocked, occluded or otherwise obstructed with respect to gas flow therethrough, or is partially closed or crushed, or is partially obstructed to limit gas flow with respect to gas flow therethrough such that there can be intermediate positions therebetween. It will be understood that when referring to the second state, or the gas flow path, may be in these partial stages as described above. Such partial stages can apply across all of the various embodiments and configurations disclosed herein, except where full closure is required for further reasons.

[0482] According to some configurations, at least one form or array of forms 401 is substantially unrestrictedly distortable or bucklable in response to the application of a force or load 405.

[0483] With respect to the form being "unrestricted" or allowing substantial "unrestricted" distortion, buckling or other shape changes of the form, this means that the "form" does not actively prevent a change in the shape / configuration of the form when a force / load is applied.

[0484] The force or load applied to the outer surface 406 of the conduit wall 402 may be applied, for example, by placing a portion of a patient interface, such as a full face mask seal, in contact with the conduit 400. For example, a nasal cannula may be in an operating position as a first patient interface on a patient, and if a second patient interface, such as a mask, is further provided to deliver respiratory therapy to the patient, the second patient interface may provide a force or load to the conduit 400.

[0485] The load or force can be manually applied by a user, such as a healthcare professional. This can be achieved by pressing on the conduit.

[0486] The relative distortion or buckling of at least one form or an array of forms 401 from a first state to a second state is to a predetermined distorted or buckled arrangement or array or configuration of the at least one form or array of forms.

[0487] During use, the force or load 405 applied to the outer surface of the conduit must be sufficient to overcome the biasing exerted by the form 401 that supports or maintains the conduit 400 in a first configuration or state (i.e., an "open" lumen state). Thus, the force or load 405 that must be applied to the outer surface 406 of the conduit 400 must be sufficient to cause distortion or buckling of at least one form or an array of forms 401 and to change the conduit from the first state to the second state against the gas pressure within the conduit. Further, the force must be sufficient to hold the conduit in the second state against the internal pressure of the conduit.

[0488] The second state can be a preferential predetermined reconfiguration (or rearrangement or relocation) of at least one form or an array of forms 401. For example, the form 401 can be designed or configured such that in the transition from the first state to the second state, the final second state is considered in terms of the ability of the form 401 to distort or buckle or otherwise be reconfigured.

[0489] In the second state, the inner surface 403 of the duct wall 402 can be made integral, whether by completely gathering them inwardly into one or partially so, such that they effectively fold over. For example, referring particularly to FIGS. 14B and 15B, where the duct 400 is in a "closed" configuration. The inner surface 403 can be made integral regardless of whether they are in contact with each other, or substantially adjacent to each other, or result in a state where the duct walls 402 are substantially closed or substantially crushed, or whether the lumen or gas flow path 404 is substantially blocked or provides an obstruction to the gas flow therethrough. Partial configurations of these substantially "closed" states can also be achieved, whereby, for example, rather than a complete obstruction or closure of the gas flow path, a reduction or restriction of the gas flow can be achieved.

[0490] The form 401 is configured to support the duct wall 402 and is biased to move the duct towards or maintain it in the first state.

[0491] The form 401 of the array of forms can distort or buckle (or be rearranged or reconfigured) from the first state towards the second state when a force or load 405 is applied, but when the force or load 405 is reduced or removed, the form or the array of forms 401 can return or recover the duct 400 to or towards the first state.

[0492] The conduit may be made of a single material having an elasticity suitable for holding the first state or configuration while being pushable into the second state or configuration. Alternatively, the conduit may be made of two materials, and the second material provides a structure that enables the conduit to hold or maintain the first state and then move to the second state upon receiving a force or load. In such an embodiment, there may be a polymeric conduit that includes a series of structures or forms that are inside, embedded in, or surround the conduit wall. In another embodiment, for example, if the conduit is made of a single material, the structure or form may not be necessary because the material will have the properties necessary to maintain the first state.

[0493] The form 401 may be a helical or helically wound or coiled member having a pitch angle of about 20° to about 70°, or about 25° to about 65°, or about 35° to about 55°, or greater than about 45° (the pitch angle is the angle between each turn or coil of the member) from a horizontal longitudinal axis extending along at least a portion of the conduit or conduit including the form or array of forms, or an angle with respect to the conduit wall.

[0494] The form 401 may be a helical or helically wound or coiled member having a pitch that is about one-fourth to about ten times the inner diameter of the conduit, or about one-half to about eight times the inner diameter of the conduit, or about two-thirds to about six times the inner diameter of the conduit, or greater than about one to about four times the inner diameter of the conduit, or the pitch may be substantially the same length as the inner diameter of the conduit (the pitch is the distance from the center of adjacent helices or helical windings or coils of the member).

[0495] The form 401 may be a helical or helically wound or coiled member having a certain pitch angle or pitch (or both) such that when a load or force 405 is applied to the outer surface 406 of the conduit 400, the form 401 can be folded or repositioned so that the form 401 is in a substantially flat arrangement when in the second state.

[0496] Form 401 may be a series of rings or ring members, such as those shown in FIGS. 13A and 13B. Each ring in this series includes a hinged interconnection with at least one other ring. The hinged interconnection can facilitate distortion or buckling of Form 401 (such as a hinged distortion from the shape of the first state).

[0497] The form may be a series of hingedly connected components arranged to provide at least substantially continuous support for the conduit wall 402 over at least a partial length of the conduit 400 including Form 401.

[0498] The helical or helical wound or coiled member, or ring member, can be formed of a relatively rigid material that is elastically deformable between a first and second configuration of the conduit. Suitable materials can include plastic materials known to those skilled in the art, or similarly metal materials known to those skilled in the art, such as steel or stainless steel, or high-strength metals.

[0499] In a further configuration, the conduit wall 402 can be constituted by at least one form or array of forms 401 that extend substantially longitudinally along the conduit wall 402 or at least substantially longitudinally along a partial length of the conduit wall 402 including Form 401. Thus, at least one form or array of forms 401 can be formed as part of the conduit wall 402 or be a flap or hinge provided thereon or therein. For example, reference is made to FIGS. 14A - 15B, which show a conduit cross-section adapted to be crushed by the application of an external force.

[0500] The flap or hinge may enable the conduit wall 402 to fold up substantially overlapping. In such a mechanism, the foam or array of foams 401 may be a bellows-type mechanism (see, for example, FIGS. 14A and 14B) or a bellows-type mechanism (see, for example, FIGS. 15A and 15B). Such a mechanism allows the conduit 400 to distort or buckle from a first state to a second state when a force or load 405 is applied. In such a configuration, for example, if the foam 401 is a hinge, such a hinge or other joint may be formed as part of the conduit wall 402, or provided therewith or therein. It is understood that the above-described configuration can be utilized by using a plurality of such hinges formed as part of the conduit wall 402, where these foams extend substantially longitudinally along the conduit wall, or at least substantially longitudinally along a partial length of the conduit wall containing such foams. In such an embodiment, the conduit may be made of a single material having sufficient elasticity to hold the first state or configuration while being pushable into the second state or configuration. Alternatively, the conduit may be made of two materials, and the second material provides a structure that allows the conduit to hold or maintain the first state and then move to the second state upon receiving a force or load. In such an embodiment, there may be a polymeric conduit that includes a series of structures or foams that are inside, embedded in, or surround the conduit wall. In another embodiment, for example, if the conduit is made of a single material, the structure or foam may be unnecessary, where the material has the properties necessary to maintain the first state but is crushable into the second state. In some configurations, the thickness of the wall section may vary to achieve a variation in crushability between the crushable portion of the tube and the remaining or non-crushable portion of the tube, as described in the following further embodiments.

[0501] Referring again to FIGS. 14A - 15B, in some embodiments, the cross - section of the crushable portion of conduit 400 includes a single - fold portion on the side of the crushable portion. This fold portion extends between the outer side 406a of the conduit and the inner side 406b of the conduit. In use, the inner side of the conduit contacts the patient's face. The fold portion includes a pair of side portions 407. These side portions spread from the fold point 407a when in the first state and present an acute or obtuse angle 407b facing outward. In the second state, the cross - section deforms at the fold point 407b, and the pair of side portions 407 come together to crush the crushable portion, resulting in the second state.

[0502] In FIG. 14A, the cross - section includes a first such single - fold portion on the first side of the crushable portion and a second such single - fold portion on the second side of the crushable portion, which is on the side opposite the first side. The first and second fold portions extend between the outer side 406a of the conduit and the inner side 406b of the conduit.

[0503] In FIG. 15A, the cross - section includes a single - fold portion (including side portion 407) on the first side of the crushable portion and a second fold point 408 on the second side of the crushable portion, which is on the side opposite the first side. The outer 406a of the conduit and the inner 406b of the conduit spread from the second fold point 408. The inner and outer sides of the conduit are folded together at the second fold point when transitioning from the first configuration to the second configuration.

[0504] In some embodiments, the angle 407b between the side portions 407 is an acute angle. For example, this angle may be 60 degrees, or 55 degrees, or 50 degrees, or 45 degrees, or 40 degrees, or less than 35 degrees.

[0505] In the second state, as shown in FIGS. 14B and 15B, the crushable portion is crushed such that the outer surface of the side portion 407 contacts, and the inner surface of the side portion 407 contacts the inner surfaces of the inner 406a and outer 406b of the conduit.

[0506] In connection with FIGS. 16A - 16C in some embodiments, a valve may be provided in the conduit. This valve may be operable by an external force provided by the mask or the user pressing on the conduit or by the valve's mechanism. For example, in connection with FIG. 16A, a further alternative embodiment is a gate within the conduit. This gate may include a pair of doors or partitions 1075 that move towards each other and preferably close when the conduit is pressed or compressed. In some embodiments, the doors may overlap and / or each door may have a complementary shape to fit together integrally without overlap. The doors may be positioned within the conduit, attached to the conduit or formed integrally therewith, such that as the conduit is compressed, the doors move together to close the lumen of the conduit. Alternatively, the doors may project from the wall of the conduit and move (slide) relative to the conduit. The gate may have a recess 1077 on one of the doors and a complementary protrusion 1079 on the other of the doors. One or more gates may be provided. In an alternative embodiment, the gate may be a single door or partition that slides across the conduit or is attached to one side of the conduit with a gap between the door and the opposite side of the conduit, such that when the conduit is compressed, the door abuts against the opposite side of the conduit to close. The door may have an opening and may provide a minimum flow level across the gate when in the closed position. One or more doors of the gate are movable transversely across the conduit from a first position where substantially a first level of gas from the gas source passes through the conduit to a second position where a second level of gas passes through the conduit. For example, one or more doors may be perpendicular to the longitudinal axis of the conduit / flow path or may be angled (e.g., 45 degrees) relative to the flow path. The first position may be in a substantially open configuration and the second position may be in a substantially closed configuration. The first gas level may be higher than the second gas level. The direction in which the gate closes may be transverse or substantially transverse to the direction of gas flow, which may help reduce the force required to close the gate and the lumen as the force of the flow does not directly oppose the gate closing direction.In some embodiments, the contact area where a pair of doors meet or where one door abuts against the side of the conduit and closes may be relatively narrow so that the operating force required to create a seal is small. For example, the width of the contact area where the doors meet or where the door contacts the conduit sidewall may be 10-20% of the diameter of the conduit.

[0507] At one position, the gate may allow gas to pass through the conduit. At another position, the gate may restrict gas from passing through the conduit. Such a gate may completely close the conduit or may result in a partial closure or constriction of the gas flow path.

[0508] In FIG. 16B, valve 549 may include a valve member 550 that is depressible. When a user / medical professional, or mask 300, presses against valve member 550 that extends through the sidewall of conduit 553, valve member 550 may move into conduit 553. When valve member 550 acts on a diaphragm or other elastic member 551, elastic member 551 may be pushed across the lumen of conduit 553 to block flow through conduit 553. In some embodiments, elastic member 551 stretches to block flow and biases valve member 550 to an open position. In other embodiments, valve member 550 is biased to an open state by the internal pressure of the gas flow within conduit 553. FIG. 16B(i) shows valve 549 with valve member 550 and elastic member 551 in an open configuration extending from the sidewall of conduit 553. FIG. 16B(ii) shows valve member 550 that has been depressed to extend into conduit 553 and is blocking flow. FIGS. 16C(i) and 16C(ii) show a similar mechanism. Valve 548 also includes a valve seat 552 that is biased against valve member 554 and biases valve member 554 away from a closed position.

[0509] In other embodiments, the system may include other valve mechanisms for stopping flow to the patient interface. For example, a butterfly valve having a valve body that is manually rotated (e.g., 90 degrees) between an open position and a closed position by a user may be provided.

[0510] Thus, in some embodiments as described above, an apparatus including a collapsed portion of a conduit or patient interface 200, or a valve located in the conduit or patient interface, provides an apparatus for switching between two modes of respiratory therapy, where the patient interface 200 provides a first mode of respiratory therapy and the mask assembly 300 provides a second respiratory mode. These modes may switch when a first portion 204 of the lumen 202 transitions from a first configuration to a second configuration.

[0511] In one embodiment, this transition is effected by the face mask 302. That is, when the face mask is placed on the patient, the seal 304 of the face mask applies a force to the first portion 204 causing the first portion 204 to transition from its first configuration to its second configuration, preferably reducing or stopping delivery of the first therapy mode, and preferably further sealing with the seal of the mask to seal with the first portion of the tube and the patient's face. Thus, due to the structure of the patient interface 200 or the conduit providing gas flow to the patient interface 200, a healthcare professional can quickly change the type of respiratory assistance delivered to the patient without having to remove the interface providing the first respiratory mode.

[0512] In some embodiments where the first respiratory assistance mode is high flow therapy, due to the structure of this patient interface 200, a healthcare professional can stop or minimize the flow rate and easily and simultaneously initiate a second respiratory therapy (e.g., by a ventilator or CPAP or high flow therapy device or anesthesia device). Further, this allows an anesthesiologist or healthcare professional managing the patient's sedation to obtain accurate information regarding the flow delivered to the patient, as the gas delivered by the second patient interface is not diluted by the gas provided by the first patient interface.

[0513] In some embodiments, the first portion 204 may expand between a first and a second configuration based on the pressure level of the gas passing through the first portion of the gas lumen. That is, the first portion of the first gas lumen may be in the first configuration when the flow pressure exceeds a first predetermined pressure level, and may be in the second configuration when the flow pressure drops below or increases above the first predetermined pressure level.

[0514] In another embodiment, the first portion 204 may be crushable naturally. That is, it can be partially or fully crushed (second configuration) when there is no gas or the gas flow through it is low / decreasing, and expands (first configuration) when there is a certain amount of gas flowing through it.

[0515] Figures 6 - 8 show various alternatives for providing the first portion 204 to the lumen 202 using one or more variations of the geometric shape, material properties, structure, and / or composition of the lumen across the first portion 204.

[0516] In one example, as shown in Figure 8, the first portion 204 includes a thinner wall 209 compared to one or more walls 207 of other portions of the first gas lumen. Preferably, there is a substantially smooth or substantially linear transition in thickness between the wall 209 of the first portion 204 and one or more walls 207 of other portions of the first gas lumen 202. The smooth transition can help prevent or reduce turbulence, improve hygiene, and / or reduce the likelihood of the gas conduit kinking.

[0517] In addition to or instead of this, the first portion 204 includes a wall that is more flexible than the walls of other portions of the first gas lumen 202. In one embodiment, this change in flexibility is due to the material of the wall. In another embodiment, this change in flexibility may be due, in addition to or instead of this, to a reinforcing element 203 provided along substantially the entire length of the lumen except for the first portion 204 (as shown in FIG. 7). Preferably, there is a substantially smooth transition, or a substantially linear transition, in flexibility between the wall 209 of the first portion 204 and one or more walls 207 of other portions of the first gas lumen 202, for example by providing a tapered reinforcing element towards the first portion 204.

[0518] In the alternative configuration shown in FIG. 6, the first portion 204 may include a wider section (i.e., a larger cross-sectional area) compared to other portions of the lumen 202. This may reduce the amount of force and / or internal pressure required to deform and / or crush this portion.

[0519] According to the configurations of FIGS. 6 - 8, a further alternative can be to provide a conduit lacking a structure or reinforcement or other form for supporting the wall of the conduit. With such a configuration, it may be possible to relatively easily crush or collapse the conduit. That is, the conduit does not have any helical or helical beads or other reinforcement. The tube can be maintained in an "open" or first state or configuration by the pressure of the gas provided to the conduit itself. When a force or load is applied to the conduit wall, the conduit can be crushed, buckled, or otherwise collapsed at the location where the force or load is applied. Such a conduit may form part of a more general gas supply conduit (e.g., the first portion 204 of the first gas conduit 202), or may be provided as a relatively short length conduit for interconnecting other components within a respiratory therapy delivery system. For example, the crushable conduit may connect two other sections of the conduit or may be provided as a short conduit section connecting to a patient interface. Such a conduit may be provided in such a system or respiratory circuit close to the patient's face, and thus in the application of another interface to the subsequent patient (e.g., when the conduit supplies gas to a nasal cannula and a full face mask is applied over it), as described above in relation to FIG. 3, a force or load can be applied to such an unstructured or unsupported conduit using part of this other interface.

[0520] In an alternative configuration, the entire tube defining the first gas lumen 202 can be configured to change the level of gas passing through the lumen by being crushed or otherwise deformed. Thus, in one example, a force can be applied to any part of the first gas lumen to reduce the gas flow through the lumen. However, it will be understood that this configuration can lead to the lumen being inadvertently crushed due to kinking or other external forces on the lumen. Therefore, it is preferred that only a portion of the lumen (i.e., the first portion 204) has this characteristic.

[0521] Although only one first portion 204 is described, it should be understood that two or more similar portions may be provided. For example, if the flow manifold 206 is configured to receive flow through two gas lumens from both sides of the flow manifold 206, two first portions 204 may be provided, one for each gas lumen, and these may be configured to be (partially or completely) crushed by the seal 304 of the face mask 302.

[0522] Figures 5, 9 and 10 show alternative configurations where, in order to limit the compression of the first portion 204, elements are provided around, inside or below the walls of the first portion 204. Preferably, this element is configured to allow a minimum level of flow through the lumen, regardless of the configuration of the first portion 204. For example, in an uncrushed state, a flow higher than the minimum level may flow through the lumen (the first portion of the lumen). In a crushed state, the element defines the minimum flow level that can be delivered by the lumen at the pressure delivered by the flow generator. Alternatively, the minimum flow level may be a level controlled, for example, by the controller 108 in accordance with one or more physiological characteristics measured from the patient.

[0523] In Figure 9, the element is a reinforcing element 220 that maintains a small opening or a second gas lumen 232 within the first portion 204 even when the first portion 204 is maximally compressed or crushed, maintaining a minimum level of flow. As shown, this reinforcing element is substantially less compressible than the wall of the first portion 204 and maintains a small opening in that portion under the external force and / or under the lower flow pressure through the tube. In the illustrated configuration, the reinforcing element 220 includes a substantially rigid portion on the opposing inner surface of the wall of the first portion 204. This rigid portion 220 is not continuous in this example, and the surrounding wall can be crushed to seal around the rigid portion and form a small opening. The rigid element may be integrally formed with the wall of the first portion 204, overmolded, or attached to the wall in some other way. In this configuration, for example, when the element 220 becomes integral while the first portion is compressed by the face mask seal 304, the second lumen 232 is formed.

[0524] In Figure 10, the element is an internal tube 230 that defines a second gas lumen 232 through, at, or in the vicinity of the internal region of the first portion 204. As shown, the tube 230 is substantially more rigid than the wall of the first portion 204 and maintains a minimum level of flow through the lumen even when the first portion 204 is maximally compressed or crushed. The internal tube 230 may be substantially coaxial with the first gas lumen 202, and may be connected to the same gas supply as the first gas lumen 202, or may be supplied by a different gas supply.

[0525] FIG. 5 shows another embodiment where an element 212 is provided in one of the internal sections of the wall of the first portion 204. By holding the element 212 spaced from the wall, a small opening or a second gas lumen 232 is formed or maintained within the first portion 204 even when the first portion 204 is maximally compressed or crushed, and a minimal level of flow is maintained. The element 212 may include a hollow cross-sectional area (as shown in FIG. 5), in which case gas may also flow through the element 212. Alternatively, the element 212 may have a solid cross-sectional area and some gas may flow around the element 212 to hold it spaced from the surrounding wall of the first portion 204.

[0526] In some embodiments, a gas conduit or tube includes a window portion that opens to a user's face during use. An exemplary embodiment is shown in FIG. 18. During use, the window portion 610 of the tube 600 is positioned on the user's face, where the perimeter 611 of the window portion of the tube is in close contact with the user's face. The tube may include a seal surrounding the window to closely contact the user's face; for example, the tube may include a lip or other sealing mechanism located around the window to closely contact the user's face. During use, the perimeter 611 of the window 600 is in close contact with the user's face, thus the user's face forms a wall of the tube that essentially blocks the window, providing a sealed lumen for gas flow to the user's airway via the patient interface 620. During use, the patient interface 620 may be used with a face mask, and the seal of the face mask extends to a position corresponding to the window 610 of the tube on the tube 600. Similar to other embodiments described herein, the force provided by the seal of the face mask against the user's face can close the tube and block gas flow to the user via the patient interface. By providing a window on the side of the tube, there is less material in the tube that is compressed by the force of the face mask against the user's face. Thus, the window portion of the tube reduces the amount of force required to compress the tube and close the lumen provided by the tube. An outer cross-section of the tube 600 is provided in FIG. 18. As shown, in some embodiments the tube includes a relatively flat cross-section, and thus the distance the tube must flatten to be closed is smaller compared to a conventional circular cross-section. In some embodiments, the tube may include a membrane covering the window. This membrane is thinner than the thickness of the tube wall. Because the membrane is thin, the amount of tube wall material that must be compressed to close the tube lumen is reduced, and the collapsing pressure of the tube is reduced.

[0527] In some embodiments, the breathing gas tube or conduit may include a balloon or accumulator or bladder (referred to herein as a bladder). The bladder may form or provide a portion of the lumen of the tube, for example as shown in FIG. 19. Bladder 710 is a section of tube 700 formed of a material having a reduced wall thickness and / or greater elasticity compared to the remaining portion 720 of the tube. In some embodiments, the bladder may be integrally formed with portions of the tube extending from each end of the bladder. In some embodiments, the bladder may be removably attachable to the tube. For example, each end of the bladder may be attached to the tube such that a first length of tube attached to one end of the bladder, the bladder, and a second length of tube attached to the other end of the bladder are included in the tube.

[0528] Using a tube 700 that includes a bladder 710, gas flow can be provided to a user via a patient interface. The bladder 710 can act as a gas accumulator, and the bladder expands as the gas pressure within the tube increases. The non-expanded configuration is shown in FIG. 19, where the expanded configuration is shown by the dashed line. The bladder can serve to reduce pressure fluctuations seen at the patient interface since the bladder expands in response to an increase in pressure, thereby evening out pressure spikes within the lumen of the tube. Further, when a patient interface such as a nasal cannula is used in conjunction with a face mask to provide two or more respiratory gas flows to a user, there can be a risk of an increase in the gas pressure provided to the user since the pressures of the gas flows provided to the user from each interface combine to cause an increase in gas pressure in the user's airway. The bladder can serve to reduce the occurrence of an increase in pressure in the patient since the bladder expands under increasing pressure and thus can reduce the increase in pressure in the patient. The bladder can be used to accumulate gas flow when used in conjunction with the crushable conduit described above. In some embodiments, the bladder provides a visual indication or indicator of an increase in pressure within the lumen of the tube to inform another person such as a user or caregiver that it may be necessary to reduce the flow rate or pressure provided to the user.

[0529] In some embodiments, the tube 700 can include a venting mechanism that operates to vent respiratory gas from the lumen of the tube into the bladder when an elevated pressure is reached. For example, the bladder can be configured to communicate with the lumen via the vent when in an open or vented configuration. The vent can open when the pressure reaches a threshold value to vent gas into the bladder. Thus, the bladder acts as an accumulator that prevents respiratory gas from being vented to the atmosphere. The bladder can also serve as a visual indicator or display of an elevated lumen pressure that can correspond to an increase in pressure in the patient's airway or at the patient interface.

[0530] In some embodiments, the bladder may be configured to adapt to a particular volume and pressure of gas reaching a particular flow rate and pressure. An additional pressure relief valve or vent may be used such that when the bladder reaches a particular vent pressure, the bladder vents to the atmosphere.

[0531] Reducing or stopping the gas flow to the nasal cannula using one or more of the devices or mechanisms described above can cause the pressure of the gas within the conduit (e.g., within conduit 202) to increase. Thus, it may be advantageous to provide one or more pressure relief devices that relieve the pressure within the conduit. As described in more detail below, this pressure relief device may be a device that only relieves pressure and may be used in conjunction with a separate device that shuts off or restricts flow. Alternatively, the device may relieve pressure and also restrict or shut off flow.

[0532] The patient interface 200 or the conduit providing gas flow to the patient interface 200 may include a pressure relief valve device or mechanism adapted to reduce or relieve the gas pressure within the first gas lumen if the flow through lumen 202 is reduced or stopped due to the first portion 204 being crushed or partially crushed.

[0533] For example, as shown by FIG. 20, a conduit 1300 may be provided for supplying or delivering gas (of gas flow 1301) to patient interface 1302. The conduit may include a crushable portion that is crushed (e.g., by mask seal 1307) to a closed configuration. The conduit includes a one-way valve 1304, and upstream of the one-way valve 1304 with respect to the direction of gas flow 1301 delivered to interface 1302, there is a vent or pressure relief valve 1305 for venting or releasing the pressure accumulated in the lumen 1306 of the conduit. The pressure relief valve can vent the pressure in the conduit, for example, when the crushable portion is in a closed configuration. The one-way valve 1304 can prevent gas administered to the patient from a second patient interface from flowing back and exiting through the vent or pressure relief device 1305 as a backflow to patient interface 1302. Further, the pressure relief valve or device can provide an additional mechanism to ensure that pressure delivered by a second patient interface does not flow back through interface 1302 due to the crushable portion of the tube not completely sealing interface 1302 from vent valve 1305. In an alternative mechanism, the conduit may include a valve that closes conduit 1308 rather than a crushable portion.

[0534] The one-way valve 1304 can be implemented in any of the systems described herein. For example, when a second patient interface is used in combination with a first patient interface and dual therapy is to be delivered to a patient, the one-way valve can enable a healthcare professional to administer gas through the second patient interface without backflow through the gas supply conduit connected to the first patient interface (i.e., nasal cannula). Without the one-way valve 1304, it may not be possible to create the desired pressure at the second patient interface on the patient due to backflow exiting the pressure relief valve 1305.

[0535] In some embodiments, when two or more respiratory assist devices (patient interfaces), such as nasal cannulas and full face masks, are used together to provide two or more respiratory gas flows to a user, one or more of the respiratory assist devices may include one or more vents and may relieve the pressure provided by the assist device. When two or more devices are used to provide two or more respiratory gas flows, there may be a risk of an increase in the pressure of the gas provided to the user because the pressures of each gas flow provided to the user may combine to result in an increased gas pressure in the user's airway. The vents in one or more of the respiratory assist devices may be provided to reduce or mitigate the risk of overpressure on the user's airway. Alternatively or in addition, a controller (e.g., controller 108) may be adapted to stop or reduce the gas flow to the patient interface when a pressure increase in the system is measured.

[0536] For example, a nasal cannula can include a vent that operates to suppress the pressure imposed by the cannula. In some embodiments, a cannula that includes one or more side arms can include a vent mechanism in one or both of the side arms. An exemplary embodiment is shown in FIG. 17. The side arm 505 of the cannula 500 can include a portion 516 (sealing portion) where the seal of the face mask closely contacts the user's face in addition to closely contacting the user's face. The side arm 505 includes or provides a lumen for gas flow that reaches the user via the cannula's manifold 506 and one or more outlets, such as nasal prongs 508. The portion 516 of the side arm can be provided with an outer shape that enables the seal of the face mask to closely contact that portion with the user's face, for example, a possible cross-section thereof is provided in FIG. 17. The side arm 505 can include a vent 510 at a position outside the sealing portion 516 of the side arm in the side arm. In other words, the vent is positioned such that it is outside the sealing range of the face mask with respect to the user's face on the side arm. When the pressure inside the face mask reaches the desired maximum pressure level, the pressure of the gas in the lumen of the side arm of the cannula rises to a level corresponding to the level when the vent of the side arm releases the pressure or suppresses the pressure in the user's airway to the desired maximum pressure. When the vent 510 operates to the open position or vent position, the vent diverts the gas flow outside the cannula and the face mask, and in the closed position or non-vent position, the gas flow is provided to the cannula.

[0537] In some embodiments, when the face mask seal 304 bearing on the side arm applies a force to the side arm, the side arm is thereby crushed or compressed and the lumen of the side arm closes. For example, in some embodiments, the face mask seal presses against portion 516, occluding the lumen of the side arm. Portion 516 of the side arm is on the inboard (downstream) side of vent 510, and thus the increased pressure in the breathing tube that provides gas flow to the side arm resulting from the occlusion or pinching of the side arm lumen vents from vent 510. For example, the side arm of a cannula may include a crushable conduit portion as described herein. The crushable portion of the cannula may include a cross-section having hinge points as shown in FIGS. 14A-15B, or any other crushable configuration described herein.

[0538] In some embodiments, the patient interface may include, or be used with, an item over which the face mask seal seals. Several embodiments of items over which the face mask seal seals are shown in FIGS. 47-54C and FIGS. 63A-63C. The item may be a block or mount 96 that contacts, or is placed in contact with, the patient's face. The block or mount may include at least one lumen therethrough for inserting a gas supply conduit or for connecting a gas supply conduit to the patient interface.

[0539] Item 96 can receive a gas supply conduit and / or can form part of a fluid passage for delivering gas to a patient interface. In some embodiments, the item includes a compressible portion or a portion that can be crushed or deformed under a force or pressure exerted, for example, from a face mask seal (Figs. 54A - 54C). In some embodiments, one or more of at least one lumen is located within the compressible portion or within the portion that can be crushed or deformed. The compressible portion may be made of any suitable material such as a polymer or silicone. The lumen and / or conduit located within the compressible portion or within the portion that can be crushed or deformed can be compressed or deformed so as to block or impede (or prevent) or partially impede the gas flow from being supplied to the patient interface 91. In some embodiments, item 96 may be an integral part of the side arm of the patient interface or may be removably attachable to the supply conduit to the patient interface or may be removably attachable to the side arm of the patient interface. In some embodiments, the item is a separate component that can be separately positioned or located on the patient, more particularly on the patient's face. The item may be a patch or pad or wearable device attachable or positionable on the patient for sensing in - situ co - use of the patient interface and the face mask on the patient during gas delivery to the patient, wherein a signal or output is generated by detection of such co - use.

[0540] The item can comprise a venting device that vents the increasing pressure in a tube that provides gas flow to the patient interface via the item when the item is in a crushed configuration that blocks or reduces gas flow to the user.

[0541] In some embodiments, the item resists external forces so that it is not compressed or crushed during use. In such embodiments, the item may include a vent device that prevents or reduces an increase in pressure in the user's airway above a maximum desired pressure, or that prevents or reduces the flow delivered to the patient's airway. The vent device or vent of the item or patient interface may be any one or more of the vents or vent devices described herein.

[0542] In some embodiments, the patient interface and / or an item associated with or used with the patient interface includes a filter device that prevents contamination of the breathing circuit that provides gas flow to the item or interface, the filter device including the vent or vent device.

[0543] Further description of item 96 related to FIGS. 47-54C and FIGS. 63A-63C is provided below.

[0544] FIG. 21A shows an embodiment of a device 1000 that releases pressure and also restricts gas flow through conduit 1001. The flow restriction may completely block the gas flow, substantially block the gas flow, or partially block the gas flow. In the vent configuration or open configuration, device 1000 vents or diverts gas flow from the conduit. In the non-vent configuration or closed configuration, the device permits gas flow to a patient interface, such as cannula 200 of FIG. 2. This embodiment of the pressure relief device 1000 is in the form of a crushable conduit with a poppet valve 1002. Specifically, the poppet valve 1002 has a valve stem 1003 and a valve disk 1004. The valve stem 1003 and the valve disk 1004 are relatively rigid and do not crush or deform even if the surrounding parts or components move, crush, or deform.

[0545] The portion 1005 of the conduit 1001 may be configured to be crushed or deformed to restrict flow. A part of the crushable portion may be a first wall in the form of a relatively rigid component 1006. The relatively rigid component 1006 may have an opening (not visible) through which the valve stem 1003 passes.

[0546] The conduit also has a second wall 1007 on the substantially opposite side. In normal use, the rigid component 1006 is substantially flush with the adjacent wall 1008 of the conduit, and substantially all of the gas from the gas source passes through the conduit. When a force is applied to the rigid component 1006, the rigid component moves towards the second wall 1007, providing a passage 1009 through which gas can flow out of the conduit into the atmosphere. In this embodiment, the passage is provided by an opening. In some embodiments, the portion 1005 of the conduit may not include an opening or vent and may operate to block the lumen of the conduit without venting. A separate vent or pressure relief valve may be separately located upstream of the portion 1005.

[0547] In one embodiment, the conduit can be crushed by pressing the mask seal 1010 against the rigid component 1006. Alternatively, the conduit may be crushed by another suitable mechanism such as a clamp or clip, or in another alternative, the conduit may be crushed by a medical professional pressing or compressing the conduit. When the conduit is crushed, the rigid portion is crushed and moves towards the position shown in FIG. 21C. As a result, gas can flow freely out of the opening and the pressure within the conduit is released. It will be understood that the gas flow may be completely restricted, substantially restricted, or partially restricted by pressing a mask or other device against the conduit. In any of these situations, the poppet valve 1002 may open to allow gas to flow out of the opening. The amount of gas flowing out of the opening may depend on the pressure of the gas within the conduit and whether the gas flow is completely restricted, substantially restricted, or partially restricted.

[0548] In an alternative embodiment, the pressure relief device may not have a poppet valve. The pressure relief device may have another type of valve, such as one of those described in connection with other embodiments herein.

[0549] For example, the embodiments shown in FIGS. 21D and 21E do not have a poppet valve. The features and operation of this embodiment are the same as those of the embodiment shown in FIGS. 21B and 21C, except that it does not have a poppet valve.

[0550] The embodiment of FIG. 21D has a second wall 1012 substantially opposite the first wall 1011. In normal use, the first wall is substantially flush with the adjacent wall 1013 of the conduit, and substantially all of the gas from the gas source passes through the conduit. When a force is applied to the first wall, the first wall moves towards or away from the second wall, providing a passage through which gas can flow out of the conduit into the atmosphere.

[0551] The features and operation of the embodiment of FIG. 21E are similar to those of the embodiment of FIG. 21D, but in addition there is a lip 1015 that is in close contact with the adjacent wall during normal use. The lip 1015 may be formed of an elastic material and is attached to a relatively rigid component 1006. When the mask seal 1010 acts on it to move the lip away from the side wall of the conduit, the vent is opened. The rigid component may be L-shaped, with a first part of the L-shaped component being transverse to the longitudinal axis of the conduit and a second part of the L-shaped component on which the mask seal acts being disposed longitudinally with respect to the conduit.

[0552] FIGS. 22A and 22B show an embodiment of a device for relieving pressure and shutting off or restricting flow. This embodiment is in the form of a conduit having a crushable portion 1017 and a non-crushable portion 1019.

[0553] The crushable portion 1017 includes a relatively flexible or soft material that crushes under the applied pressure, or the portion 1017 may have a rigid portion that connects to an adjacent non-crushable portion of the conduit by a pivot that allows it to open and close. The crushable portion 1017 preferably includes a relatively rigid portion 1023 that prevents the crushable portion from crushing until an intentional external force is applied, such as pressing the mask against the crushable portion. A flexible or soft portion 1027 is located at the end of the crushable portion to provide a seal against the non-crushable portion 1021. The non-crushable portion may include a rigid portion 1025. In an alternative embodiment, the rigid portion may be omitted and the tongue 1027 of the crushable portion may be in close contact with the wall of the conduit. The crushable portion has an extended tongue 1027 that fixes the crushable portion to the underside of the wall of the conduit to prevent the crushable portion from opening outward under pressure from the gas flow. During normal use, the crushable portion is substantially flush with the adjacent wall of the conduit, and substantially all of the gas from the gas source passes through the conduit. The crushable portion may act as a flap that moves between a closed position shown in FIG. 22A and an open or vent position shown in FIG. 22B.

[0554] The crushable portion is arranged such that it crushes when an external force is applied, such as when the mask is placed on the patient's face. The non-crushable portion is relatively rigid and does not crush or deform even if the crushable portion moves, crushes, or deforms.

[0555] When the crushable portion of the conduit is crushed, the rigid portion 1023 moves toward the position shown in FIG. 22B, creating a passage through which gas can flow out of the conduit into the atmosphere. As a result, gas can freely flow out through the opening created between the tongue 1027 and the non-crushable portion 1019, releasing the pressure within the conduit. It will be understood that by adding a mask or other device to the conduit, the gas flow may be completely restricted, substantially restricted, or partially restricted. In any of these situations, the crushable portion is crushed or deformed to allow gas to flow out through the opening. The amount of gas flowing out of the passage may depend on the pressure of the gas within the conduit and whether the gas flow is completely restricted, substantially restricted, or partially restricted. The amount by which the crushable portion is crushed within the conduit (and thus the venting amount achieved) can be controlled by the user varying the sealing force provided by the face mask 300 on the crushable portion.

[0556] Figures 23A - 23C show another pressure relief device. In this embodiment, the pressure relief device includes a flexible portion or valve member 1031 that extends over and closes the opening 1033 of the conduit. When viewed from above, the flexible portion has an elliptical shape. When viewed from the side, the flexible portion is curved to conform to the shape of the conduit. The flexible portion is also curved when viewed from the end face and conforms to the curve of the conduit. Alternatively, the flexible portion may have a curvature that does not substantially match the curvature of the conduit or may be substantially planar. In these alternative embodiments, the flexible portion has a natural or undeformed position and is biased toward that natural position to close the opening. The relief pressure at which the flexible portion lifts away from the opening can depend on the properties of the material used for the flexible portion and / or the size and shape of the flexible portion.

[0557] Figure 23b shows the valve without the flexible portion 1031. The flexible portion has a stem 1032 that fits into a hole in a member extending across the opening. A retaining mechanism (e.g., an enlarged diameter portion) 1032a on the stem 1032 holds the flexible portion in place.

[0558] The flexible portion 1031 is or includes a flexible or elastic material, such as silicone. Under standard operating gas pressure, as shown in Figure 23c, the flexible portion covers the opening and can prevent or at least substantially suppress gas from flowing out of the conduit through the opening. When the pressure of the gas in the conduit reaches a threshold pressure, the edge of the flexible portion moves away from the conduit, and the flexible portion will have the shape shown in Figure 23d.

[0559] The opening 1033 may have a shape similar to that of the flexible member, i.e., the shape may be elliptical when viewed from above. In a further alternative embodiment, there may be two or more openings closed by the flexible member. In another alternative embodiment, there may be two or more openings each closed by the flexible member. As shown in Figure 23a, the advantage of two or more flexible members is that there should always be at least one flexible member that is not placed on or blocked by the surface and can move freely to open.

[0560] Figures 23E - 23G show a pressure relief device similar to that shown in Figures 23A - 23D, but this pressure relief device is located within the chamber 1035. Positioning the pressure relief device within the chamber can be advantageous because the pressure relief device does not vent gas near the patient. This pressure relief device is protected because it is not on the flexible conduit but is located on a separate chamber with which the conduit is in fluid communication. In addition, this pressure relief device may be away from bedding and other items that may block or interfere with the vent and may be near the patient.

[0561] Figures 24A and 24B show one embodiment of a device for releasing pressure and shutting off or suppressing flow. In this embodiment, the pressure relief device has a lever 1037 mounted within a conduit, the lever having a pivot 1039, an operating portion 1041, and a sealing portion 1043 that substantially seals an opening 1045 of the conduit such that substantially all gas from the gas source passes through the conduit. In this configuration, the operating portion 1041 is on one side of the pivot 1039 and the sealing portion 1043 is on the same side of the pivot. In this embodiment, the lever 1037 is a leaf spring positioned inside the conduit. The conduit may be formed of one or more materials that have dimensions and are soft or flexible such that the conduit does not retain its shape without support from other components. The leaf spring 1037 can prevent or at least substantially suppress the conduit from being crushed, deformed, or closed unless an external force is applied.

[0562] The sealing portion 1043 is in the form of a boss or ridge that engages the opening 1045 of the conduit. When the boss or ridge engages the opening, gas flow out of the conduit is blocked or at least substantially suppressed.

[0563] For example, when the operating portion 1041 is moved by pressing a mask against the conduit directly above the operating portion, the lever 1037 pivots about the pivot 1039, the sealing portion 1043 moves away from the opening 1045, and a passageway is provided through which gas can flow from within the conduit to the atmosphere.

[0564] Figures 25A and 25B show another embodiment of a device for releasing pressure. This embodiment is used with a conduit that is crushable or has a crushable portion.

[0565] In this embodiment, the pressure relief device has a lever 1047 mounted within the conduit, the lever including a pivot 1049, an operating portion 1048, and a sealing portion 1050 that substantially seals an opening 1052 of the conduit such that substantially all gas from the gas source passes through the conduit. In this embodiment, the lever 1047 is a rigid component positioned inside the conduit. In this configuration, the operating portion 1048 is on one side of the pivot 1049 and the sealing portion 1050 is on the other side (opposite side) of the pivot 1049. A mask seal acts on the side of the conduit to act on the operating portion, causing pivoting of the lever about the pivot point. Pivoting of the lever moves the sealing portion, disengaging its engagement with the opening on the opposite side of the conduit. The sealing portion 1050 may have a boss or ridge that engages the opening 1052.

[0566] When the crushable portion of the conduit is crushed, the lever 1047 moves toward the position shown in FIG. 25B. As a result, gas can freely flow out of the opening 1052 and the pressure within the conduit is released. It will be understood that adding a mask or other device to the conduit may completely, substantially, or partially restrict gas flow. In any of these situations, the lever 1047 moves to allow gas to flow out of the opening 1052. The amount of gas flowing out of the opening may depend on the pressure of the gas within the conduit and whether gas flow is completely, substantially, or partially restricted. In some embodiments, the lever 1047 is biased toward a closed position where the opening is closed. To open the opening, a force (such as by applying a face mask seal) is required to move the lever against this bias. One benefit of the mechanism shown in FIGS. 25A and 25B is that flow is vented on the side of the tube facing away from the person applying the mask to the patient. In some embodiments, it is preferred to vent or direct gas flow away from the patient and / or caregiver.

[0567] In an alternative embodiment, a lever is provided on another component or part of the patient interface. For example, the cannula may have a lever.

[0568] Figures 26A and 26B show another pressure relief device. In this embodiment, the conduit has a movable portion 1051 connected and positioned by a thin joint or web 1055 to an adjacent portion 1053 of the conduit. This movable portion has one or more openings 1057. A disk or valve member 1059 extends over the conduit and seals it or at least substantially seals it. As shown in Figure 26A, the disk 1059 is in close contact with the portion of the conduit adjacent to the movable portion. The disk 1059 has a stem 1052 for connecting the disk to the movable portion 1051 of the conduit.

[0569] The thin joint or web 1055 is created such that the pressure relief device remains in the closed position until the pressure in the conduit reaches a threshold pressure. When the pressure of the gas in the conduit reaches the threshold pressure, the movable portion 1051 pops out and assumes a second configuration, where the joint bends upward and allows flow to vent through the opening 1057.

[0570] Figures 27A - 27D show another pressure relief device. In this embodiment, the pressure relief device includes a valve member that is a flexible arm 1061 and a body portion 1062 that partially or completely wraps around the conduit. The flexible arm and the body portion are preferably integrally formed as a single member. When the pressure of the gas in the conduit reaches the threshold pressure, the pressure bends the flexible arm 1061 upward to the position shown by the dashed line in Figure 27A. As a result, the gas can flow freely out through the opening 1063 and the pressure in the conduit is released. In some embodiments, the user can rotate / reposition the arm on the conduit so that the vent opening 1063 remains uncovered if constant or long - term venting is desired. The arm may be made of, for example, a piece of silicone, spring steel, other suitable plastic material or metal material.

[0571] Figures 27E and 27F show another pressure relief device. In this embodiment, the pressure relief device includes a sliding member 1098 provided in the wall of conduit 1099. Member 1098 is slidable between an open position that opens an opening 1097 in the wall of the conduit, as shown in Figure 27F, and a closed position that covers opening 1097, as shown in Figure 27E. When a user attempts to use the mask with a first patient interface, the user can slide member 1098 to the open position to vent pressure from the conduit that can be crushed by the mask.

[0572] Figures 27G and 27H show another pressure relief device. In this embodiment, the pressure relief device includes a sleeve or ring element 1095 provided on the wall of the conduit. Member 1095 can be rotatable between an open position that opens an opening in the wall of conduit 1094, as shown in Figure 27H, and a closed position that covers opening 1096, as shown in Figure 27E. Alternatively, sleeve 1095 can be slidable and can open or cover opening 1096. Sleeve or ring element 1095 may have an opening that aligns with opening 1096 in the wall of conduit 1094, or may extend partially around conduit 1094 such that opening 1096 of conduit 1094 is positioned between circumferential ends of sleeve 1095 to position sleeve 1095.

[0573] Figures 27I and 27J show another pressure relief device. This pressure relief device includes a silicone valve member 1092. The slit in the silicone member 1092 can be opened by excess pressure in the system, and the pressure in the system can be released. The silicone member may be a diaphragm including a slit.

[0574] Figure 28 shows a cross-section of another pressure relief device. This embodiment can be positioned on a relatively rigid component such as a filter.

[0575] In this embodiment, the pressure relief device includes a flexible portion or valve member 1065 that extends over and closes the opening 1067 of the conduit. This flexible portion is made of or includes a flexible or elastic material, such as silicone. The flexible portion has a natural position shown in FIG. 28 and can be biased toward that natural position. In an alternative embodiment, the flexible portion can be replaced with a relatively rigid portion that is biased, for example by a spring, to return to the position shown in FIG. 28.

[0576] Under standard operating gas pressure, the flexible portion 1065 covers the opening and can prevent or at least substantially suppress gas from flowing out of the conduit through the opening. When the pressure of the gas in the conduit reaches a threshold pressure, the flexible portion moves away from the opening, enabling gas to flow through the opening and releasing the pressure in the conduit.

[0577] FIG. 28 shows two openings 1067 closed by a flexible member. In another alternative embodiment, there may be one or more openings, and each of such openings is closed by a corresponding flexible member. One flexible member may close two or more openings. The opening may be formed as a circumferentially extending slot.

[0578] FIG. 29 shows another pressure relief device. This embodiment is shown positioned in a conduit. This embodiment has a valve member 1069 that closes the opening 1071 to prevent or at least substantially suppress gas flowing through the opening. This pressure relief device has a pair of legs 1073 between the conduit and the valve member 1069. These legs are biased to the position shown by the solid line. The shape and composition of the legs are selected and designed such that they hold the valve member in the closed position until the pressure reaches a threshold point at which the valve opens (the position shown by the dashed line). When the pressure drops and the force applied to the valve member decreases, the valve member can return to the closed position shown by the solid line. Alternatively, when the mask is removed, the user may manually push the valve into the closed position.

[0579] Figures 30A and 30B show another pressure relief device. This embodiment can be positioned on a relatively rigid component such as a filter.

[0580] This embodiment of the pressure relief device has a valve member 1081 with outwardly extending flaps 1083. These flaps close the opening 1084 of the rigid component. The center of the valve has an opening 1085 through which gas can flow into the conduit. When the pressure of the gas in the conduit reaches a threshold pressure, the flaps lift. The flaps are preferably flexible and elastic.

[0581] This embodiment of the pressure relief device can be positioned, for example, on a filter 1087. However, it will be understood that this embodiment of the pressure relief device can be located anywhere in the gas flow path within the rigid portion.

[0582] Figure 31 shows a pressure relief device (although this is not essential) located at the end of a filter. This can be positioned anywhere in the system.

[0583] This embodiment of the pressure relief device is used with components of a respiratory assistance system that delivers pressurized gas from a gas source to a patient. The components of the respiratory assistance system have openings. This pressure relief device includes a valve body 1091 that can engage a conduit for delivering pressurized gas from the gas source to the patient. The valve body is located within a component of the respiratory assistance system and has a portion that can engage closely with the opening. During normal use, the valve body is biased towards closing the opening of the component of the respiratory assistance system, and substantially all of the gas from the gas source passes through the conduit. When the pressure of the gas in the conduit reaches a threshold pressure, the valve body opens the opening of the component of the respiratory assistance system, providing a passage through which gas can flow out from within the component of the respiratory assistance system to the atmosphere. In this embodiment, a spring 1089 holds the valve body 1091 in its normal use (closed) position until the pressure of the gas in the conduit reaches the threshold pressure.

[0584] Multiple of the above-described pressure relief devices are incorporated with, include, or provide the crushable portion of the conduit, and the said portion of the conduit operates between a closed or non-vent configuration and an open or vent configuration by being crushed under the influence of an external force. The external force can be brought about by the seal of the face mask being placed over the crushable portion of the conduit, or by the user or a healthcare worker pressing on the crushable portion. For example, the exemplary embodiments described in relation to FIGS. 21B to 22B and FIGS. 24A to 25B are pressure relief devices that operate by an external force applied to the crushable portion. In such embodiments, the venting device can operate between a vent position and a non-vent position by a second interface pressing on a component of the device, such as the lever 1050 in the embodiment of FIG. 25A. Alternatively, the device may be operated by the user or a medical professional pressing on a component of the device.

[0585] Multiple of the above-described pressure relief devices, such as the exemplary embodiments of FIGS. 23A to 23G and FIGS. 26A to 30, operate between a closed or non-vent configuration and a vent or open configuration by system pressure. These embodiments operate when the system pressure rises above a threshold. These devices can directly sense the pressure acting on a valve member of the pressure relief device, for example. Alternatively, these devices may be operated by a controller that receives a pressure indication from a sensor located within the system, and when the sensed pressure reaches the threshold, the controller energizes an actuator (such as a solenoid) to operate the valve member between a non-vent configuration and a vent configuration. Alternatively, a mechanical switch or actuator that can be operated by the user or a medical professional to operate the valve member between a non-vent configuration and a vent configuration may be provided.

[0586] Another pressure relief device is described in connection with FIGS. 32 and 34. A pressure relief device 89 is shown in FIGS. 33 and 34, and a nasal cannula 81 adapted to be used with this pressure relief device is shown in FIG. 32. The cannula 81 and the pressure relief device may be used together in a respiratory assistance system, such as the system 100 of FIG. 1. The pressure relief device 89 is adapted to sense a system pressure, such as the pressure delivered to a patient via the cannula 81. The nasal cannula 81 has a body portion 83 that can be positioned in an operative position on a patient's face. The nasal cannula 81 also has at least one nasal prong 85 extending from the body portion 85, and the nasal prong 85 is adapted to direct a gas flow into a patient's nasal nostrils when the body portion is in the operative position. In the illustrated embodiment, the nasal cannula has two prongs 85.

[0587] This system also has a pressure sensing or sampling line or conduit 829. In the illustrated embodiment, the sensing line 829 has an opening or inlet 87 at or near the nostrils of the patient's or user's nose to sample / detect the pressure at that location. However, this pressure sensing line may be used to detect the system pressure at another location within the system. The pressure relief device 89 is a mechanical valve. In the illustrated embodiment, the pressure relief device includes a shuttle or piston 813. The pressure relief device 89 selectively controls the gas flow entering the patient's nasal nostrils from the nasal prong 85. Since the outlet end 821 of the pressure sensing line is open to the piston 813, the piston 813 senses or is affected by the pressure sensed by the pressure sensing line (described in more detail below). In the illustrated embodiment, the piston 813 senses the pressure at the nostrils via the pressure line 829. In such an embodiment, the pressure relief device may be used as a safety pressure limiting device to ensure that the maximum acceptable pressure in the patient is not exceeded. In an alternative embodiment, by measuring the pressure, an indication that a second auxiliary system is being applied to the patient may be provided. For example, a face mask may be applied to the patient, where the face mask may block a portion of the conduit 831. When the face mask is applied or the conduit is blocked, the system pressure within the conduit may increase. A pressure sensor may detect this pressure and provide an indication that the mask is applied. The increase in pressure may cause the device 89 to operate and vent the pressure within the conduit 831. The nasal cannula 81 is configured to allow the simultaneous use of a second respiratory assistance system. For example, as previously described in connection with FIG. 3, a face mask (indicated by the dashed line and reference numeral 8100 in FIG. 35) may be placed over the patient's mouth, nose, and cannula 81.

[0588] In the example illustrated in FIGS. 32 to 34, when the pressure at or near the nostrils of the patient's nose exceeds a predetermined value, the pressure acting on the piston moves the valve 89 to a closed configuration or a partially closed configuration to restrict the gas flow entering the patient's nasal nostrils from the nasal prong 85. When the pressure at or near the nostrils of the patient's nose is below a predetermined value, the valve 89 is in an open configuration and the gas flow entering the patient's nasal nostrils from the nasal prong 85 is allowed.

[0589] The flow rate can be controlled so that the system pressure does not exceed a predetermined value. The predetermined value may be any of the following: · An initial value · A "safety" value set by the user, · The pressure maintained by the cannula flow before the face mask is placed on the cannula, or · Related to the flow rate, i.e., allowable pressure = A × flow rate^B + C × flow rate^B - 1… (where A, B, C, etc. are constants).

[0590] The predetermined value may be a fixed value or a variable value. If the value is variable, it can be adjusted by either the user, the controller, or both.

[0591] In connection with FIGS. 33 and 34, the valve 89 has a housing 811, a valve member or piston 813, a compression spring 815, and a rotatable knob 817. The rotation of the knob is indicated by an arrow in FIGS. 33 and 34.

[0592] The housing 811 has a flow source inlet 819, a post-measurement pressure inlet 821, a flow source outlet 823, and an over-flow outlet 825. The flow source inlet receives flow (e.g., high flow from the flow generator 102 of FIG. 1) from the flow source via the flow source conduit 827. The post-measurement pressure inlet 821 receives a pressure corresponding to the pressure sensed at the sensing end 87 of the conduit 829. The flow source outlet 823 delivers gas to the patient via the cannula conduit 831. In the illustrated embodiment, the cannula conduit 831 and the post-measurement pressure conduit 829 extend between the cannula 81 and the pressure relief device 89. In the illustrated embodiment, these two conduits 829, 831 are aligned with each other.

[0593] The spring 815 biases the valve member 813 toward the position shown in FIG. 33, and the force of the pressure at or near the nostrils of the patient's nose against the spring force controls whether the flow from the flow source is delivered to the patient. With reference to FIG. 33, when the pressure at or near the nostrils of the patient's nose is less than the opposing pressure exerted by the spring 815, the valve member 813 is pushed by the spring toward the open position, and gas flow is delivered from the flow source to the patient. With reference to FIG. 34, when the pressure at or near the nostrils of the patient's nose is greater than the opposing pressure (and friction within the device) by the spring force 815, the valve member 813 is pushed to the closed position by the flow pressure sensed by the pressure line 829, and no gas flow is delivered to the patient. In the illustrated embodiment, the flow from the flow source is vented from the over-flow outlet 825.

[0594] The tension of the spring 815 may be a fixed spring tension or, as shown in FIG. 33, a variable spring tension. An example of a variable spring tension is a variable end-expiratory positive pressure (PEEP) valve. By rotating the knob 817, it is possible to control the opposing force of the spring 815 against the measured patient pressure force by adjusting the preload. The adjustment can also be achieved by other methods such as a linear actuator.

[0595] This system may operate in an on / off fashion. That is, valve 89 may have an open position where gas flows through the valve unimpeded and a closed position where gas flow through the valve is blocked. In an alternative embodiment, the system may have a valve member with one or more intermediate positions where flow is partially restricted. These one or more intermediate positions provide variable control of the flow. When the flow is vented, for example, by a restriction orifice at the vent, an audible noise may be generated to alert the user of the vent.

[0596] In an alternative embodiment, the system may have a valve member with one or more intermediate positions where flow is partially vented. These one or more intermediate positions provide variable control of the flow.

[0597] In an alternative embodiment, the pressure relief may also be controlled by electronic switching, where an electrical signal controls a valve that controls the gas flow to the patient.

[0598] In connection with FIG. 35, the pressure relief may be controlled by a processor having software. Unless otherwise described below, the features and operation of the second embodiment shown in FIG. 35 are the same as those described in connection with FIGS. 32 - 34. In this embodiment, the system further includes at least one processor and a user interface 833. A predetermined value is set by and / or displayed to the user via the user interface 833. For example, a maximum pressure (Ptarget) is set by the user. In addition or alternatively, the system may have an initial value. A typical initial value may be 20 - 40 cm H2O, or in some configurations about 0 cm H2O.

[0599] The pressure sensor 835 detects the pressure at or near the nostrils of the patient's nose or at some point within the system, and transmits data indicating the pressure to the controller. The data indicating the measured pressure is compared by the controller with data indicating a predetermined value, for example, the maximum pressure (P_target). The flow rate (Q) delivered to the patient via the nasal cannula is adjusted accordingly to ensure that it does not exceed P_target. Specifically, the processor controls a valve (e.g., pressure relief valve 89) or a flow generator to restrict the gas flow entering the patient's nasal nostrils from the nasal prong when the pressure at or near the nostrils of the patient's nose exceeds a predetermined value, and to allow the gas flow entering the patient's nasal nostrils from the nasal prong when the pressure at or near the nostrils of the patient's nose is below the predetermined value.

[0600] In an alternative embodiment, the controller may have two pressure sensors with a known obstruction (i.e., an orifice plate) therebetween. The pressure difference between these two pressure sensors can be used to determine the flow rate. The system can control the flow rate to be achieved such that the pressure does not exceed the allowable P_max value for a given flow rate by using this flow rate. This can be described by a mathematical equation, a step function, or a look-up table within the software.

[0601] Calibration can be performed to account for pressure sensor drift and adjust the offset of the flow sensor accordingly when the controller knows that valve 89 is closed and there is no flow. Such a calibration routine can be implemented for any electrically controlled pressure relief device described herein. When valve 89 is controlled by the controller, valve member 813 may not be a piston that senses the sampled system pressure. The position of the valve member is actuated by an actuator (e.g., a solenoid) controlled by the controller in response to the pressure measured by sensor 835.

[0602] The pressure sensor 835 may be in various different positions. For example, the pressure sensor 835 may be located on or near the nasal cannula, or inside the area that can be covered by a face mask. In some configurations, the pressure sensor 835 is located on at least one nasal prong 85 or near it. For example, on the nasal prong, inside the patient's nostril as shown in FIG. 35, or on the patient interface. In some configurations, the pressure sensor is located on a conduit adapted to deliver gas to the nasal cannula. In some configurations, the pressure sensor is located on or near a flow generator or a pressure relief device. In some configurations, the pressure sensor is located on a humidification chamber, a dry line (the conduit from the flow generator to the humidifier), or a gas tube. In some configurations, the pressure sensor 835 or the pressure line 829 is remotely mounted and pressure is connected via a conduit from any of their positions.

[0603] The described system may include a nasal cannula 81, the patient's nose, and / or a face mask 8100 (e.g., an anesthesia mask) placed to cover the patient's mouth. The mask 8100 delivers a gas flow or pressurized gas in addition to the flow (e.g., high-flow therapy) that the user receives through the nasal cannula 81. Thus, the pressure delivered to the patient's airway may exceed an acceptable pressure. This can occur when a sealed mask is used. Therefore, a pressure relief feature or a reduction in flow may be used to prevent an over-exceedance of the acceptable pressure.

[0604] The pressure relief device may be a flow controller positioned within the system to limit the flow / pressure delivered to the patient. The flow controller may be operable based on an input from the pressure sensor or the pressure within the system provided / detected through a pressure sampling line. In some configurations, the flow controller controls the flow of a high-flow therapy device. Alternatively, the flow controller controls a second gas source or a flow generator. For example, the flow controller may control the gas flow of the face mask. In a further alternative, the flow controller controls the gas flows of a high-flow therapy device and a second gas source or a flow generator.

[0605] The mask flow source (not shown) can be controlled by its own variable pressure relief valve (not shown). An independent pressure relief on the cannula that can be set by the user means that the user has more control over the pressure delivery from each flow source.

[0606] The specific embodiments of the pressure relief device described herein are aimed at suppressing the magnitude of the pressure delivered to the patient. Specifically, the described specific embodiments can be used in situations involving the simultaneous use of multiple respiratory assistance systems, such as nasal cannulas and anesthesia masks.

[0607] The specific embodiments described herein can also be used without other respiratory assistance systems, i.e., the nasal cannula may be the only respiratory assistance system used in the patient. The described embodiments can suppress the magnitude of the pressure delivered from the high-flow source.

[0608] A method of providing respiratory assistance to a patient will now be described. As shown in FIG. 35, a nasal cannula 81 is placed in an operative position on the patient's face. Gas flow is sent into the patient's nasal nostrils via a nasal prong 85. At some point in the system, for example, by a sensor located at or near the patient's nasal nostrils or by the valve member of the pressure relief valve (e.g., via a pressure line 829), the pressure is measured or detected. When the pressure exceeds a predetermined value, the gas flow entering the patient's nasal nostrils from the nasal prong is restricted. The flow rate may be reduced or the flow may be blocked.

[0609] The flow can be restricted when a change (increase) in pressure is detected. Alternatively, when the mask is placed over the patient but the sensor is positioned outside the cannula such that it does not cover the interior of the patient's nostrils, the flow can be restricted when the measured pressure exceeds zero. Alternatively, when the pressure inside the system is detected using a sensor / pressure line (the system pressure can be affected by applying the mask over the cannula such that the mask causes backpressure on the system), the flow can be restricted when the pressure exceeds a predetermined threshold pressure determined for a particular flow rate. The last two alternatives described assume that the mask 8100 is applied.

[0610] When the pressure is below a predetermined value, a gas flow entering the patient's nasal nostrils from the nasal prong is allowed.

[0611] Controlling / restricting the gas flow entering the patient's nasal nostrils can result in excessive / undesirable gas flow from the gas source. This excessive / undesirable gas flow can be addressed in various ways. For example, it may be vented outside the mask / nasal cannula. Alternatively, the excessive / undesirable high-flow gas may be sent back to the flow source. In other embodiments, when the flow source can be stopped by shutting off the flow, it may not be necessary to vent the excessive / undesirable high-flow gas, or in the case of a source from a flow generator such as a blower, the source may be turned off. In an alternative embodiment, the total flow to the patient may be controlled / restricted by a pressure relief device. A sensor may measure the flow and venting may occur in response to a flow limit.

[0612] FIG. 36 shows another embodiment of the pressure relief device 8000 in a closed state. FIG. 37 shows the same pressure relief device 8000 in an open state. This device includes a valve member 8001. The valve member 8001 covers and seals an opening 8002 in the side wall of the conduit 8003. When the pressure in the breathing conduit 8003 exceeds a predetermined pressure, the valve member 8001 moves away from the opening 8002, enabling venting through the opening 8002 as shown in FIG. 37. The pressure relief device 8000 can also include a biasing member 8004 (e.g., a spring) that biases the valve member 8001 to a closed position that seals the opening 8002. When the pressure in the breathing conduit exceeds a predetermined pressure, the valve member 8001 moves against the biasing member 8004 away from the opening 8002. The pressure relief device 8000 preferably includes a cap or housing 8005 that houses the valve member 8001 outside the conduit 8003. The cap or housing 8005 can prevent the valve from being inadvertently blocked.

[0613] Figures 38A and 38B show a pressure relief device 8010 including a main valve 8011 and a pilot valve 8012 that controls the operation of the main valve 8011. When the pressure (Pc) in the conduit 8013 falls below a predetermined value, the pilot valve 8012 closes. When the pilot valve 8012 closes, Pc acts on both sides of the piston 8014 of the main valve 8011. The piston 8014 has a first side with a first area (A) and a second side with a second area (a) that is smaller than the first area (A). When the pilot valve 8012 closes, the pressure Pc acts directly on the first side of the position 8014, and the pressure PC acts on the second side of the piston 8014 via the pilot valve 8012. Since the area of the first side of the piston 8014 is larger, a greater force is applied to this side of the piston 8014, and the piston 8014 is held in the closed position. When the pressure Pc becomes higher than a predetermined value, the pilot valve 8012 opens, and the flow from the conduit 8013 is vented as shown in Figure 38B. As a result, the pressure on the second side of the piston 8014 becomes smaller than the pressure on the first side of the piston 8014, and in that case, the piston moves from the closed position to the open position. This enables the gas from the conduit 8013 to be vented from the main exhaust port 8015 of the main valve 8011 of the pressure relief device 8010.

[0614] Figure 39 shows a valve 8020 that stops the flow when the pressure Pc exceeds a predetermined value. The pressure may be local to the valve 8020 or may be sensed by the valve 8020 via a pressure line 8025 at another location within the system or a similar pressure line 829 described in connection with FIG. 32. When the force exerted by the pressure is less than the spring reaction force, the plug 8021 seats in the retracted position and gas can flow down the conduit. FIG. 40 shows the plug 8021 extending into and blocking the conduit 8023. This occurs when the force exerted by the pressure Pc exceeds the spring reaction force. The plug 8021 blocks the flow through the system until the pressure drops, at which point the plug 8021 retracts and gas begins to flow again. When the flow is blocked, the flow may be vented further upstream by any one of the pressure relief devices described herein or the controller may stop the flow.

[0615] FIGS. 41A and 41B show another embodiment of a pressure relief valve 8030. FIG. 41A shows the device in its closed state. FIG. 41B shows the same device in its open state. When the pressure in the breathing conduit 8034 exceeds a predetermined pressure, the plunger 8031 moves upward against the reaction force provided by the spring, providing a path for the gas flowing down the breathing conduit 8034 to be vented.

[0616] In any of the embodiments, the spring need not necessarily be in the form of a coil spring as shown. Instead, the spring may be, but is not limited to, a leaf spring, a diaphragm spring, or a compliance material.

[0617] Any of the above pressure relief devices may be located anywhere between the flow source and the cannula within the system. Preferably, the pressure relief device is located downstream of the humidification chamber so that the humidification chamber controller does not need to handle large changes in flow within the humidification chamber. Examples of suitable locations for the pressure relief device include a filter, a location at the humidification chamber outlet, a location within a circuit connector, or a location as an attachment to the flow source. The pressure relief device may be in the cannula or may be in the vicinity of the cannula. In some embodiments, it may be preferable to have the pressure relief device on or near the patient interface. Having the pressure relief device on or near the patient interface is beneficial in that the pressure delivered to the patient can be estimated more accurately compared to having the system have the pressure relief device further upstream and within the system.

[0618] In some embodiments, venting the conduit through the pressure relief device before applying the mask on the crushable portion of the conduit may make the conduit more prone to being crushed when the mask is applied.

[0619] The pressurized conduit that provides gas flow to the patient may include a certain level of hysteresis. Due to the hysteresis of the conduit, the pressure relief device may open at a pressure higher than the pressure at which the pressure relief device closes. This feature may prevent or at least substantially suppress the pressure relief device from constantly oscillating between the open configuration and the closed configuration.

[0620] As described above, for example, as described in connection with FIG. 3, a respiratory system may be provided that enables delivery of gas by at least two different respiratory assistance modes from a plurality of supply sources and further enables rapid and easy change of the type of respiratory assistance mode by a physician, clinician, or medical professional. Further details of the various functionalities and embodiments of the system are provided below, and the benefits of such embodiments are outlined.

[0621] The following embodiments can be used with the respiratory therapy system described above or any other suitable respiratory therapy system, and while achieving high-flow operation, can easily achieve switching between respiratory assistance modes and / or other functions or benefits. These embodiments can be configured to deliver gas to a patient at a high flow rate as described herein.

[0622] Function 1 - Switching between therapy modes The following switching configuration enables high-flow operation via a first patient interface with the ability to perform one or more of the following: · Deliver an accurately concentrated volatile agent to an anesthetic machine using a second patient interface with the minimum amount of agent possible · Deliver manual respiration to the patient using a bag when required by the second patient interface · Quickly and easily switch between respiratory assistance provided by the first patient interface and the second patient interface · Confirm airway patency using a bag and mask (second patient interface) · Optionally, a clinician can regain control of manual ventilation using a bag.

[0623] Currently, there is no easy way to integrate the use of high flow into anesthetic practice. It may be possible to split high flow into a completely separate system / flow source, but it would be desirable to have a configuration that allows for easy switching between high-flow respiratory assistance and anesthetic machine respiratory assistance. Also, it would be desirable if high flow could be quickly and easily turned off or reduced.

[0624] In current practice, a user can split high flow into a separate flowmeter attached to the wall gas supply. There is no integration or special design with anesthetic machines regarding the use of high flow in anesthetic practice.

[0625] In some embodiments, a switching configuration (switching configuration 1) includes a user interface device that enables a user to control gas flow in a respiratory therapy system for delivering high-flow gas to a patient, the user interface device comprising at least one controller or device operable by the user for controlling the flow rate and / or concentration of at least one gas through the patient interface and for substantially blocking or reducing the flow rate or turning off the flow of at least one gas through the patient interface.

[0626] The gas may be high-flow gas. Another said gas may be anesthetic gas or adjunct gas or any other suitable gas.

[0627] The patient interface may be a nasal cannula. The controller actuated by the user may include a switch. In some embodiments, the switch is positioned on the patient interface. Alternatively, the patient interface may be another non-sealed patient interface. In a further alternative configuration, a combination of multiple patient interfaces may be used, such as a combination of a non-sealed interface and a sealed interface, or two sealed interfaces.

[0628] In one configuration, the user interface device is a separate device remote from the patient interface. This configuration is shown in FIG. 42A. The gas flow rate is preset by the user via the user interface device 2500. Before placing the patient interface (e.g., 200, 300 of FIG. 3) on the patient, the user uses a first user-operable controller that can be coupled to a rotameter (e.g., set to 40 LPM or 70 LPM) to set the desired oxygen and / or air flow rate. A second user-operable controller includes a user-operable switch 2502 that controls a valve for one or more flow sources 2102. The switch is illustrated as a toggle switch, but may be in any suitable form. In a preferred embodiment, the switch includes two states and may be a "one-touch" switch, or other on / off button or lever. The switch provides a rapid way to turn the flow rate on / off or to rapidly increase the flow rate to a preset value, rather than prior art techniques that can take time to gradually increase or decrease the flow.

[0629] When switch 2502 is turned on, the valve opens and gas (preferably oxygen) can be delivered to the patient at a preset flow rate, for example via cannula 2200. The user interface device 2500 has a gas connection 2503 for fluidly connecting to a patient interface used to deliver gas to the patient. When switch 2502 is turned off, the valve closes, blocking the flow to the patient or at least reducing the flow rate to the patient. In one alternative, only the flow to one patient interface (e.g., a high flow interface) can be blocked or reduced. In another alternative, the flow to two or more patient interfaces can be blocked or reduced. The valve can be turned off when the user decides to start providing respiratory assistance to the patient from the anesthetic machine. By user-operable controllers 2504, 2506, the user can blend gases, such as air and oxygen, and / or can independently set the flow rates of those two gases. Alternatively, only one type of gas, such as oxygen, may be provided. The user interface device may include more user-operable controllers and may be capable of blending three or more gases in desired ratios. Alternatively, two or more functions of the controllers 2502, 2504, 2506 actuated by the user may be combined. For example, a single user interface, such as a touch screen, may be provided that allows the user to blend gases and block or reduce the flow to the patient.

[0630] The on / off switch 2502 can also control the power to the humidity generator 2104. For example, when humidity is generated by electrical energy in the tube, the tube can be energized using electrical connection 2508. When switch 2502 is turned off, this can also disconnect the power to the electrical connection and thus to the tube. In this way, the humidity and the flow can be turned on / off simultaneously.

[0631] When the switch is switched to the "off" mode, instead of completely turning off, the flow can be reduced to, for example, 5 LPM. This can be beneficial as a minimum "backup" flow. For example, even if the clinician forgets to turn the high flow back on immediately after the patient's extubation, the low flow rate can provide at least some oxygenation to the patient. The minimum flow can be preset to a value expected to meet the patient's inspiratory demand (e.g., 30 LPM). The maximum flow can be 70 LPM or more, for example 100 LPM or 150 LPM. There may be multiple preset values, for example three or more preset values, for example 0, 30, and 70 lpm. These can be actuated by a switch or mechanism with three or more positions corresponding to different preset values.

[0632] Alternatively, the switch 2502' may be on the cannula 2200 to facilitate access, as shown in FIGS. 43A - 43C. In this case, the switch 2502' can be a mechanism that either allows the flow to pass through to the interface in the on / open configuration (FIG. 43B) or blocks the flow to the cannula in the off / closed configuration (FIG. 43C). In other words, the switch 2502' is a valve; the terms switch and valve can be used synonymously to refer to a valve unless otherwise specifically indicated by the context. Various valve mechanisms are described above in relation to FIGS. 21A - 22B. When blocked, the delivered flow can be vented from the pressure relief valve 2510 along the gas conduit 2512 as shown in FIG. 43C, or vented back to the gas supply, or the valve may have a venting mechanism.

[0633] This configuration may be provided as a mechanical switch or valve 2502' that allows for the restriction, occlusion, or complete obstruction (i.e., closure or blockage) of the gas flow through the gas conduit or through the patient interface such as a nasal cannula during operation.

[0634] The operation of switch 2502' can be manually performed by the user, or the switch may be actuated by placing a second patient interface on the switch (i.e., as the patient interface such as a mask is placed on the patient, or when the patient interface placed on the patient contacts the switch 2502' which can be provided as part of a first patient interface such as a nasal cannula or conduit as described above in connection with FIGS. 21A - 22B).

[0635] Switch 2502' can partially or completely block the gas flow path, and can partially or entirely prevent the gas flow through the gas flow path through the conduit or patient interface (such as a nasal cannula). Thus, the gas flow to the end of the conduit or the outlet of the first patient interface can be stopped. Switch 2502' may be provided as part or a component of the conduit or patient interface.

[0636] In some configurations, the conduit or patient interface including the switch may be provided with a vent or pressure relief device that releases the pressure buildup resulting from the switch being actuated and the gas flow to the outlet from the conduit or one or more outlets of the patient interface being partially or completely stopped or blocked.

[0637] In some configurations, the switch may be one that partially blocks the gas flow path through the conduit or patient interface when actuated, or completely blocks the flow path. The switch may be located or positioned at various useful locations, for example on a foot pedal for actuation by the user's foot, or may be a remote switch that can be attached to a bed, anesthetic face mask, pillar, anesthesiologist's clothing, etc.

[0638] Switch 2502' can be provided for use in conjunction with, in particular, self - supporting tubing (i.e., tubing that is not naturally crushable or crushable).

[0639] Alternatively, the configuration of switch 2502' is used in conjunction with a crushable tube 2202 (relating to the embodiment of FIG. 42B or any other crushable conduit described herein) and can supply high-flow gas to the cannula. The tube is configured to be crushed to allow the mask to seal on the tube. In one example, the tube can be crushed by applying a mask over the tube as described above. Alternatively, the tube can be crushed by any suitable mechanism, such as by physical structure or by changing or controlling the flow and / or pressure delivered through the tube. In such embodiments, the crushed tube does not completely block the tube and the switch or valve 2502' can block the tube.

[0640] Advantages of using a crushable tube in combination with switching configuration 1 include one or more of the following: · There is no need to remove the cannula - it is possible to bag the patient by sealing the face over the cannula with a mask. · Since the flow is already stopped, suppression of the flow through the cannula does not depend on the pressure of the mask seal against the crushable tube. Also, there is no need to press the mask against the force of the gas flow accumulated in the tube. · Clinicians can use existing bag / mask consumables. · High flow can be stopped or reduced by a switch at the gas source (rather than ventilating), which can help maintain oxygen supply.

[0641] In one embodiment, during delivery of gas flow, only at least one section of the cannula tube 2202 is open (open and unobstructed). When the high-flow gas source (e.g., source 124 of FIG. 1) is turned off or the flow is significantly reduced, the tube is more prone to being crushed. The high flow can be turned off / reduced for the user to desire the use of mask ventilation. In some embodiments, crushing the tube can make it possible to more effectively seal the face with the mask.

[0642] The wall thickness of the tube 2202 may decrease at the crushable portion illustrated and described above in FIG. 42B, thereby reducing the structural rigidity and enabling crushing, or other features may be utilized to enable the reduction in diameter, closure, or blockage of the tube or lumen.

[0643] In some embodiments, the switching configuration (switching configuration 2) is a cannula for delivering high-flow gas to a patient; a mask for delivering gas to a patient; and a respiratory therapy system including a pressure sensor associated with the cannula, the system being configured to adjust the flow of high-flow gas through the cannula in response to at least one type of pressure change detected by the sensor.

[0644] The pressure sensor may be provided on the outer surface of the cannula or on the outer surface of a tube in fluid communication with the cannula.

[0645] The system may be configured to reduce or substantially stop the flow of high-flow gas when the pressure sensor detects a pressure increase. The pressure sensor may be configured to detect a pressure increase in response to the placement of a mask on the patient, the exhalation of the patient, or the actuation of an anesthesia bag.

[0646] The system may further include a valve that partially or substantially blocks the flow of high-flow gas through the cannula in response to the detected pressure increase.

[0647] As shown in FIG. 44A, high-flow gas is supplied from the auxiliary gas supply through cannula 2200; for example, via flow meter 2124. Ventilation to mask 2300 is supplied by anesthetic device 2404 and bag 2406 via a suitable lumen or tube 2306. A pressure sensor 2238 is provided on the outer surface of the tube 2200 / cannula 2200 interface to measure the pressure P1 of the system. During high-flow delivery, the pressure sensor 2238 typically reads P1 = 0, where P1 = 0 is the ambient pressure. When mask 2300 is applied over cannula 2200 (such as when a clinician attempts to bag-mask ventilate a patient), the pressure P1 increases slightly and exceeds the ambient pressure. This change in pressure can be transmitted pneumatically or electrically back to the high-flow gas source. Subsequently, in response thereto, the high flow is adjusted by the processor, for example, turned off or reduced.

[0648] When the pressure is transmitted pneumatically, as shown in FIG. 44C, the pressure change can actuate valve 2240 to shut off the flow source. When P1 = 0, valve 2240 is open as shown in FIG. 44B, allowing high-flow gas to cannula 2200. When the pressure P1 rises above 0, this causes plunger 2242 to be pushed into the flow path, shutting off or partially shutting off the high-flow gas. Shutting off the flow allows vent 2250 of high-flow gas conduit 2202 to open to release excess flow, or the flow source providing the gas flow can be turned off. When bag 2406 is compressed and additional flow is pushed into mask 2300, and also during exhalation (where the bag is not compressed but the patient's exhalation can be trapped within the mask), the pressure P1 can rise further.

[0649] Figure 44D shows a possible flow pattern resulting from the configuration of Figure 44A. Initially, high flow / cannula flow 2426 is delivered and the pressure at P1 = 0. The mask 2300 is applied ("mask on"), the pressure at P1 rises, and the flow through the cannula 2200 is stopped (at 2425 in Figure 44D). When the user starts compressing the anesthesia bag 2406 (at 2426 in Figure 44D), a further rise in P1 is caused during inhalation. If the pressure rise of the mask 2300 exceeds the setting of the APL (adjustable pressure limiting) valve, this causes the APL valve on the anesthetic 2410 to vent and the pressure to plateau. When the user stops compressing the bag 2406, P1 initially rises as the patient begins to exhale passively (at 2427 in Figure 44D), and then decreases as the patient reaches the end of exhalation.

[0650] Alternatively, the high flow / cannula flow may decrease during "mask on", and this decrease may vary depending on the pressure measured at P1. For example, the higher the pressure measured at P1, the greater the decrease in the delivered flow may be, while the lower the pressure measured at P1, the smaller the decrease in the delivered flow may be.

[0651] If the pressure change is instead communicated back electrically to the high flow gas supply 2102, this may interrupt or reduce the flow rate by the operation of a valve, a flow restrictor, or the opening of a vent that can divert the flow through an orifice of relatively low resistance. Alternatively, the pressure may be pneumatically communicated via a pressure line terminated, for example, at the pressure sensor 2238, but the operation of the flow reduction / interruption is implemented in software by the controller 2108 or another processor.

[0652] To ensure that only a portion of the high-flow gas has its flow restricted, the spring force of the flow restrictor valve 2240 can be designed so that it does not compress even when subjected to a pressure of up to 40 cmH2O. The APL valve is likely to be set to less than 40 cmH2O. Therefore, the APL valve 2410 will vent any additional pressure above 40 cmH2O measured at the mask 2300, and the spring will never be subjected to >40 cmH2O. This ensures that the high-flow gas supply valve remains open and that some high-flow is always allowed to flow to the patient. Alternatively, a relatively lightweight spring can be used for valve 2240 so that only a small pressure is required to completely block the high-flow gas (e.g., 1 - 2 cmH2O, which can be incurred simply by the act of placing the mask 2300 over the cannula).

[0653] Advantages of switching configuration 2 include one or more of the following: · Clinicians can use existing bag / mask consumables. · There is no need to remove the cannula - it is possible to bag the patient by sealing the face over the cannula with the mask. · High-flow is automatically stopped by the system - the user does not need to manually turn high-flow on / off. · High-flow can be stopped or reduced by the system (rather than vented), which can help maintain oxygen supply. · The user can set the "minimum" level of high-flow delivery or pressure at any time. · The mask does not need to completely seal the conduit to the cannula to block / reduce high-flow. It may be easier than completely crushing the tube. · Even when high-flow is completely blocked, the mask flow does not need to overcome the backpressure from the high-flow gas source. · Pressure measurement can be very sensitive - it does not depend on the user creating a good seal with the mask.

[0654] In some embodiments, the switching configuration (switching configuration 3) is a cannula circuit for delivering high-flow gas to a patient through a cannula; a bag circuit that enables a user to manually deliver gas to the patient by actuating a bag; and a connector that connects the bag circuit to the cannula circuit, the connector including an isolator that substantially prevents high-flow gas from entering the bag circuit, and includes a respiratory therapy system.

[0655] The connector may be configured such that both high-flow gas and gas from the bag circuit can be delivered to the patient through the cannula. Alternatively, the connector may be configured to substantially prevent high-flow gas from being delivered to the cannula when the bag circuit is connected to the cannula circuit.

[0656] The isolator may include one or more walls or valves in the connector.

[0657] The cannula may be a nasal cannula having at least one prong that is received in a patient's nostril, the cannula including one or more inflatable cuffs associated with the one or more prongs that help create a seal in one or more of the patient's nostrils.

[0658] The system may be configured to inflate one or more cuffs in response to actuation of the bag.

[0659] This configuration may additionally or alternatively include a nasal cannula for delivering gas to the patient, the cannula including at least one prong that is received in a patient's nostril, the cannula including one or more inflatable cuffs associated with the one or more prongs that help create a seal in one or more of the patient's nostrils.

[0660] Refer to FIG. 45A. For example, in the pre-oxygenation phase, high flow is delivered from the auxiliary gas supply unit / flow meter 2124 through a cannula circuit including a cannula 2200. When the user attempts to manually deliver gas to the patient, i.e., provide manual ventilation to the patient (e.g., when the patient is apneic and the user attempts to keep the patient's lungs recruited), a bag circuit 2412 is attached to the high flow gas supply tube of the cannula circuit (at connection region C). The high flow gas supply tube has a valve to prevent leakage when the bag circuit is not attached.

[0661] The bag circuit 2412 includes a connector 2420 (shown in FIGS. 45C-i and 45C-ii). The upstream side has a restriction orifice 2422 that limits the amount of high flow gas that can pass through the connector along tube 2202 to reach the patient (any excess gas can be vented further upstream via vent 2250). The connector 2420 has a valve 2424 to separate the high flow gas HFG from the gas BF flowing into the bag. This allows gas delivery to the patient to be from either the high flow gas (HFG) or the bag flow source (BF), preventing the high flow gas HFG from returning to the bag flow BF and inflating the bag 2406. This means that the clinician controls bag inflation only by the fresh gas supply from the anesthesia machine 2404.

[0662] The user may attempt to fully control the patient's inspiratory gas flow via the bag 2406 and allow only high flow delivery during exhalation. Compressing the bag 2406 delivers gas from it, and the pressure increase caused by the gas flow pushed from the bag can close the valve of the high flow gas supply tube, completely blocking or restricting the high flow gas during inhalation. This valve may be able to open when there is no bag flow and allow high flow gas to be delivered during exhalation.

[0663] Referring now to FIG. 45A, when the bag 2406 is inflated by fresh gas from the anesthesia machine 2404 and then actuated by compressing the bag, the bag gas BF passes through the connector 2420 and flows out to the patient. When the bag 2406 is compressed, the valve blocks or at least reduces the high flow gas, preventing HFG from being delivered to the patient. The HFG can be vented further upstream. The valve is designed such that the force from the BF flow pressure required to overcome the HFG pressure can be small. For example, FIGS. 45C-i and 45C-ii have a large surface area on which the BF flow acts, and the direction of blocking the HFG flow is perpendicular (rather than in line) to the HFG flow. This means that there is no need to close the valve against the opposing HFG flow. The valve may simply be kept open by its own weight (in the downward position as shown), or a spring may be provided upward to increase the level of force required for closing. When the bag 2406 is compressed, as shown in FIG. 45A, a secondary flow of gas (SG) can also be delivered via the conduit 2430 to the inflatable cuffs 2260 on the cannula prong 2208 (these cuffs may be in fluid communication so as to inflate together). The gas SG to the prong causes the cuffs 2260 on the prong to inflate, creating a seal at the nostrils. When the clinician attempts to control the patient's breathing, a seal is required to effectively achieve this (in normal practice, a sealed mask is used).

[0664] When the compression of the bag 2406 is released, the valve opens and HFG can flow to the patient (see Figure 45C-i). The flow is no longer supplied to the cuff 2260, and the cuff contracts. This releases the interface seal, allowing the patient to breathe passively, and the gas flow diverges around the prong 2208. The release of the seal is important when a minimum level of high-flow gas is still being delivered (through the restrictor orifice). If the seal is not released, over-inflation of the patient can be caused by continued gas delivery. Also, the release of the interface seal means that during exhalation, additional high-flow gas is pushed back down the prong and the bag cannot inflate beyond the clinician's expectation. In this way, the prong is always inflated when flow is delivered from the bag and the bag is not compressed, and the bag is always deflated when high-flow is delivered.

[0665] The cuff 2260 may be designed to inflate at very low pressure, such that inflation can be maintained or even increased throughout inspiration, even if the bag flow BF is low at either end of the inspiration phase. In this second case, an increase in the inflation level can occur as the bag 2406 is compressed more strongly / more flow is supplied. Since greater inflation leads to increased sealing and thus increased pressure delivery, this can assist the clinician in adjusting the pressure delivered to the patient.

[0666] Alternatively, a check valve can be installed in the conduit 2430 to the cuff 2260 to maintain a constant inflation throughout the use of the bag and prevent deflation unless high-flow is initiated. For example, in relation to Figures 45B, 45B-i and 45B-ii, when the bag is compressed and SG flows, the check valve 2261 (shown as a ball check valve) opens, allowing the cuff 2260 to inflate. The pressure of the HFG flow (P HFGBy using the pressure tap (line) 2501 that measures [[ID=]], the flow of SG to the cuff via the valve 2340 can be blocked or unblocked. When there is no HFG delivery, PHFG is approximately 0. This enables the SG to flow through the valve 2340 to the cuff (Figure 45B-i). When the compression of the bag stops, the check valve 261 closes, preventing the gas in the prong from escaping and returning to the bag. When the flow from the bag stops, the valve 2240 shown in Figure 45C opens, allowing HFG to flow. The HFG flow causes an increase in PHFG, and since the valve 2340 operates via the pressure line 2501 to release the block of the vent device 2262, the cuff can contract via this vent as shown in Figure 45B-ii.

[0667] Figure 45D-i shows the flow pattern. The flow of the prong (cannula) 2200 is delivered to the patient. Initially, high flow is delivered. Next, the connector 2420 is inserted, the bag 2406 is compressed to create positive pressure bag flow, and the high flow decreases. The flow of the prong is the total flow delivered to the patient as a combination of high flow and bag flow. The prong expands until it is fully inflated and then is maintained at a constant level of inflation (contraction is prevented by the check valve). When the bag flow stops, the high flow delivery increases again. When the bag flow stops and high flow is delivered, the prong contracts.

[0668] As an additional example, an inflatable oral insert may be connected to the nasal prong 2208. This may be useful for mouth breathers to prevent pressure loss during breathing assistance when their mouth is open.

[0669] Even during bagging of the patient, delivery of PEEP (positive end-expiratory pressure) is ensured by maintaining a minimal high-flow gas supply. In this way, it can be ensured that the patient always receives a certain level of positive pressure, which can help prevent atelectasis. FIG. 45D-ii shows the waveform when at least a low level of HFG is always maintained (the valve in FIG. 45C only partially blocks the HFG).

[0670] When the user attempts to administer a volatile agent to the patient, high-flow delivery may affect the concentration, diluting the volatile agent and potentially requiring additional agent to be added to obtain the correct concentration. This can be costly. In an alternative embodiment, the high-flow gas supply may be completely blocked when the bag circuit connector 2420 is plugged in. In this case, there may be no orifice on the right side of the connector as shown in FIG. 45E. This may mean that ventilation is supplied only from the bag 2406, which is controlled by the clinician during connection. This may be more intuitive for the clinician as they can see when the bag, which is the only source of ventilation, is connected and high-flow is no longer provided.

[0671] If the prong 2208 is not sealed throughout the entire respiratory cycle, volatile agents may still be lost to the atmosphere, which may not be desirable. When a mask is used in prior art systems, the volatiles can be recycled through a closed (sealed) system.

[0672] Figures 45B-iii and 45B-iv show a possible embodiment in which a check valve 2261 that is not opened by the start of high flow is included in the cuff gas supply section. Here, once the gas flow enters the cuff 2260, it cannot escape again. As a result, after the bag 2406 is first compressed, the inflation of the cuff is maintained. This is safe because when the high flow is blocked, that is, when the embodiment of the connector 2420 in FIG. 45E is used, the patient can exhale back into the bag 2406 / anesthesia machine 2404. The clinician can control this, and the risk of over-inflation is limited. Returning the exhaled breath to the machine 2404 helps to conserve drugs, reduce costs, and prevent the administration of drugs into the room, which can be dangerous for the caregivers involved. According to the check valve 2261, the cuff 2260 can remain inflated unless actively contracted, for example, via an actuatable release valve 2262 shown on the left side of the check valve 2261 by the user. This active contraction can be actuated by the user venting the pressure that presses on a part of the valve 2262 to inflate the cuff. Alternatively, this release valve 2262 may be connected to the bag tube connector 2420, and the valve is released when the bag tube is disconnected from the system. Maintaining the cuff seal also means that the clinician can completely control the patient's breathing over the entire cycle.

[0673] Figure 45F shows the flow pattern of this. When the connection 2420 is inserted and the HFG is blocked, the high flow drops to zero. The prong flow is what is ultimately delivered to the patient.

[0674] To control the pressure relief when the bag 2406 is connected, the APL valve may still be set by the user. If the prong is inflated / sealed, the delivery of excessive pressure can be vented via the APL. If the prong is contracted because the bag 2406 is not connected, the risk of barotrauma is limited. If the prong is contracted during non-sealed breathing with the bag connected, the pressure transmitted to the anesthesia machine is minimal, but since the prong is contracted, the risk of barotrauma is also limited in this case.

[0675] The advantages of switching configuration 3 include one or more of the following: · No mask - only cannula interface: · No need to replace the patient interface · No difficulty in achieving a good mask seal · The cannula is more comfortable - improved patient tolerance · High - flow is automatically vented by the system when using the bag - no need for the user to manually turn high - flow on / off · The prong can be kept sealed throughout the respiratory cycle when using the bag. Since the volatile agent returns to the anesthesia machine, it results in drug savings and prevents drug leakage into the room · Visibility and access to the patient's airway are improved, and there is no need for the user to hold a mask over the patient

[0676] In some embodiments, the switching configuration (switching configuration 4) includes a cannula circuit for delivering high - flow gas to the patient through a cannula; a bag circuit that enables the user to manually deliver gas to the patient by operating a bag, the bag circuit being in fluid communication with the cannula circuit; and a valve arranged to enable delivery of high - flow gas to the cannula when the bag is not operating and to enable delivery of gas from the bag circuit to the cannula when the bag is operating, and includes a respiratory therapy system

[0677] This configuration may additionally or alternatively include a nasal cannula for delivering gas to the patient, the cannula including at least one prong that is received in the patient's nostril, the cannula including one or more inflatable cuffs associated with one or more prongs that assist in creating a seal in one or more of the patient's nostrils

[0678] Refer to FIG. 46A. The bag circuit 2412 including the bag 2406 is permanently connected to the high flow cannula circuit 2202. The valve system 2470 controls whether to deliver the flow from the high flow source 2124 or from the bag 2406 / anesthesia device 2404. The change between the auxiliaries is actuated by the flow from the bag 2406 when the bag 2406 is actuated by compressing it. The bag acts as the main controller. When the bag is actuated, bag ventilation is the primary respiratory assistance. When the bag is not being used, high flow is delivered to the cannula 2200. Most of the above description in the previous configuration also applies to this configuration.

[0679] Referring to FIG. 46B, normally high flow is delivered to the patient (when the bag 406 is not compressed). When the bag is compressed, this closes the valve 2470 (which may be of the type shown in FIG. 45C-i or FIG. 45C-ii). This cuts off or at least reduces the high flow gas supply to the patient. This enables gas to be delivered to the patient only from the bag 2406 (as described above, the bag gas can also inflate the prong cuff). Compressing the bag also delivers gas to the gas reservoir 2472 shown below the valve in FIG. 46A.

[0680] Reservoir 2472 has a check valve 2473, and thus is filled from the bottom by the bag flow BF, but the flow can only exit through the upper orifice 2474. The reservoir may be rigid or made of an expandable material that can accommodate more air and expand when BF flows. The orifice has a restricted opening to control the gas leakage rate. When the bag 2406 is released from compression / when not compressed, no further flow is delivered from the bag and the patient can breathe passively. During this time, the flow reservoir 2472 starts to discharge, and the flow from the reservoir 2472 keeps the valve 2470 closed and shuts off the high-flow gas source. The orifice 2474 may be sized such that it takes approximately one exhalation time (e.g., 3 seconds) to empty the reservoir 2472 when it is completely filled. Thus, the valve 2470 will remain closed throughout the breath. Alternatively, the valve 2470 may be energized by a controller and held for a period, e.g., over the breathing time. The reservoir 2472 may also be connected to the prong cuff 2260, provide flow to the cuff during breathing, and keep the cuff inflated throughout the entire respiratory cycle. This means that the patient's exhaled flow returns to the tube and reaches the bag / anaesthetizer.

[0681] If the bag 2402 is not compressed after this time, this may indicate that the clinician has finished bagging the patient. Since the reservoir 2472 is empty, it becomes possible to open the high-flow gas valve 2470 and deflate the prong cuff, and then the high-flow gas starts to flow again (see ☆ in Figure 46B). If bagging is restarted, this high flow will be blocked again.

[0682] This system shuts off high flow throughout the respiration when the patient is bagging and also maintains the interface seal. Therefore, during this time, it is also possible for the clinician to control the gas delivered to the patient and accurately control the volatile agent delivery. If the prong remains sealed throughout exhalation, all exhaled flow can return to the anesthetic machine. This means that since the volatile agent returns to the anesthetic machine, it results in savings of the agent and prevents leakage of the agent into the room.

[0683] Also in this case, the user can still set the APL valve 2410 and control the main pressure relief when using the bag 2406. When the bag is not in use, the prong shrinks, so the risk of pressure injury is limited.

[0684] The advantages of switching configuration 4 include the following: · Integrated design - High speed, no user input required for system - to - system changes (no need to insert tubes) · Automatic switching between therapies during bag compression · High flow is automatically vented by the system when using the bag · No need for the user to manually turn high flow on / off · The prong can be kept sealed throughout the respiratory cycle when using the bag · Since the volatile agent returns to the anesthetic machine, it results in savings of the agent and prevents leakage of the agent into the room · At the end of exhalation, the prong cuff is automatically pressure - released Maskless - cannula interface only.

[0685] One or more of the advantages of this switching configuration include one or more of the following: · It is possible to easily turn high flow on / off · When turned on, the flow rate immediately increases to the preset value and treatment delays (e.g., in emergencies) are avoided · The switch mechanism enables a rapid drop in high - flow rate / pressure during closure ·When not in use, turn off the flow and humidity to save gas and power. ·The cannula / interface can be left in place. ·Partially blocking the high-flow gas supply means that a minimum flow rate can still be delivered to the patient. This can be useful in ensuring that PEEP (positive end-expiratory pressure) is provided until the very end of exhalation. Current manual bag-mask ventilation strategies from current anesthetic machines do not provide PEEP at the very end of the procedure. ·Easy switching between respiratory systems (between high-flow and bag-mask ventilation) ·Allows the user to control ventilation and drug delivery with a sealed interface as they are accustomed to in current practice. ·Allows exhalation during high-flow delivery by controlling the seal of the interface. ·Maskless - cannula interface only: - Simple / easy, no need to change the interface on the patient - No difficulty in achieving a good mask seal - The cannula is more comfortable than the mask - improved patient tolerance.

[0686] Function 2 - Subconscious / apneic therapy setting ·The clinician needs to manually change the respiratory assistance settings as the patient's condition changes. ·Since the existing interface cannot be used throughout intubation, typically there is a period without assistance during the apneic period during intubation attempts. ·Minimal ventilation assistance can be provided after extubation.

[0687] Current respiratory assistance systems do not automatically change the type of assistance upon detection of spontaneous breathing or apnea. This is either because the clinician usually changes it or, in any case, removes the interface at this point.

[0688] It is desirable to provide different treatment settings when the patient is unconscious and then when the patient becomes apneic.

[0689] A respiratory therapy system suitable for unconsciousness / apnea therapy settings includes a patient interface for delivering gas to a patient; and a processor configured to deliver gas to the patient at a first flow rate and / or pressure when the patient is breathing spontaneously and at a second flow rate and / or pressure when the patient is not breathing spontaneously by controlling the gas flow through the patient interface.

[0690] The system may be configured to detect the presence of apnea and to deliver gas at the second flow rate and / or pressure in response to the detection of apnea. The system may be configured to detect the presence of apnea based on a decrease in the activation of brain signals, diaphragmatic signals, intratracheal pressure, or CO2 measurements.

[0691] The first flow rate and / or pressure may include a relatively low flow rate and / or pressure, and the second flow rate and / or pressure may include a relatively high flow rate and / or pressure.

[0692] The processor may be a controller 108 or any other suitable type of processor. The processor may be a remote processor.

[0693] FIG. 65a shows exemplary steps that may be implemented using the method and system of this configuration.

[0694] This method and configuration may have one or more of the following features: · The therapy can be changed between a low-flow / low-pressure setting when the patient is awake and a high-flow / pressure setting when the patient is asleep. For example, deliver 30 - 40 LPM (or a flow rate that appears to meet the inspiratory demand) when breathing spontaneously and increase to 70 LPM for apnea oxygenation. · The presence of apnea may be based on a decrease in the activation of brain signals (EEG), diaphragmatic signals (EMG), intratracheal pressure, or CO2 measurements: - EEG: The medulla oblongata of the brainstem contains an inhalation center composed of neurons that send signals to the diaphragm and external intercostal muscles. EEG sensors on the scalp can monitor the activity of the medulla oblongata to detect when an inhalation signal is sent or when the transmission stops. Alternatively, frequency analysis can be used to detect changes in certain EEG frequencies. For example, delta waves have an amplitude of 20 - 400 μV and a frequency band of 0.5 - 4 Hz, and are seen in situations where brain activity is extremely low, such as during general anesthesia. An increase in amplitude or the presence of the delta frequency band indicates that the anesthesia is effective, and thus can indicate when apnea begins. - EMG: Respiratory muscle EMG signals (e.g., examining the airway with Edi, or placing EMG sensors on the diaphragm or intercostal muscles). During spontaneous inhalation, as the respiratory muscles move for inhalation and a negative intrapulmonary pressure is generated, a positive electrical signal is generated. Regular EMG fluctuations can indicate respiration. A decrease in EMG fluctuations can indicate when anesthesia takes effect and apnea begins. - Intratracheal pressure measurements: For example, by the patient interface 200. Figure 65b shows an example of how the pressure line 280 can be incorporated into the cannula 200. Regular pressure fluctuations indicate respiration. Figure 65c shows possible flow patterns. The flow delivered during spontaneous breathing varies to meet the patient's inhalation demand, and during exhalation, a base level of flow can be delivered to provide PEEP, or other desired flow characteristics, or during spontaneous breathing, a constant flow of, for example, 30 L / min can be delivered. A decrease in fluctuations associated with the onset of anesthesia indicates apnea. At this point, the flow increases. - CO2 measurements: For example, by end - tidal monitoring. Similar to the intratracheal pressure method, fluctuations indicate respiration, and relatively stable recordings indicate apnea. · As shown in Figure 65c, after a decrease in respiration is detected, there may be a suitable "waiting period" or delay (e.g., 5 seconds) before changing the therapy. · Alternatively, for patients at risk of aspiration, instead, the therapy can reduce the risk of reflux by decreasing the delivery pressure at the onset of apnea (e.g., during rapid induction). In this case, the flow can be decreased or kept at a low level during apnea, and instead, the oxygen concentration can be maximized.

[0695] Similarly, when spontaneous breathing recovery is detected at the end of anesthesia, there may also be a change in therapy, such as an increase or decrease in flow rate or pressure. When apnea ends and spontaneous breathing is detected, the flow rate and / or pressure can be returned to the first flow rate and / or pressure, or adjusted to a different flow rate and / or pressure than during apnea, for example, to take into account the following: It is known that in many patients, postoperative respiratory function can be difficult. For example, obese patients may exhibit a rapid deterioration in gas exchange after extubation for the same reasons seen during the preoperative period. A decrease in aerated lung volume due to atelectasis, narrowing of peripheral airways, and difficulty in the flow of airway secretions can lead to the so-called postoperative pulmonary restrictive syndrome, which can cause hypoxemia.

[0696] Furthermore, after the period of mechanical ventilation, the threshold at which PaCO2 stimulates the recovery of spontaneous ventilation increases, and thus the recovery of spontaneous ventilation is delayed. Also, the ventilatory response to acidosis becomes blunted, and the patient's compensatory ability decreases. Anesthetics also reduce the normal defense response to hypoxia, even at low volatile drug concentrations. Therefore, as low concentrations of volatile drugs can persist for several hours into the postoperative period, the patient may continue to be at risk of hypoxemia.

[0697] After spontaneous breathing recovery is established, delivering a high flow rate and / or oxygen concentration after anesthesia can help reduce the inspiratory work of breathing, increase arterial oxygenation, and compensate for the decreased respiratory drive that can persist after anesthesia. See Figure 65d.

[0698] Any change in flow / pressure can follow a ramp-like increase rather than a step-like increase, as shown in Figure 65d.

[0699] Advantages of the unconscious / apnea therapy setting function include one or more of the following: · improved patient comfort while unconscious, the ability to continuously deliver therapy, which improves patient tolerance and thus the effectiveness of the therapy. As the patient's respiratory drive will be functioning normally, further pressure assistance is not thought to be necessary · After the patient loses consciousness, further therapeutic assistance is provided, which is useful because the patient's respiratory drive weakens during apnea. It also helps to increase oxygenation before an intubation attempt. · The increase in oxygenation during apnea is automatically initiated as early as possible, rather than waiting for the user to start. The oxygenation time before intubation is maximized.

[0700] Function 3 - Compensation for the suction effect Clinicians often suction the patient's airway immediately before intubation to remove secretions, improve visibility, and reduce the risk of aspiration. If the patient has just received pre - oxygenation for a period of time, this suction can act to remove oxygen - containing gas from the patient's airway and reduce that oxygen reserve. Current respiratory assistance systems do not automatically compensate for this suction effect.

[0701] A respiratory therapy system suitable for compensating for the suction effect comprises a patient interface for delivering gas to the patient; a sensor arranged to detect fluctuations in pressure within the patient interface or within a conduit in fluid communication with the patient interface; and a processor configured to adjust the gas flow to the patient interface to deliver gas at a higher flow rate to the patient interface when a decrease in airway pressure is detected.

[0702] The processor may be configured to adjust the gas flow to the patient interface to deliver gas at a higher flow rate to the patient interface when it is determined that a decrease in airway pressure is occurring during and / or after apnea, or at any other time when the patient's breathing pattern is not considered to be a natural breathing pattern.

[0703] The processor may be controller 108 or any other suitable type of processor. The processor may be a remote processor.

[0704] Figure 66a shows exemplary steps that may be implemented using the method and system of this configuration.

[0705] This method and configuration may have one or more of the following features: · A patient interface such as cannula 200 has a pressure sensor 280 thereon, and the pressure sensor is arranged to detect or sense fluctuations in the airway pressure in the patient interface or in a conduit in fluid communication with the patient interface. The pressure sensor 280 may instead be positioned on the conduit rather than on the cannula itself. After apnea has been detected (using one of the methods described in the previous section), if there is a decrease in airway pressure, it indicates either an inspiration of spontaneous breathing or a pressure drop due to suction. If this is detected immediately after apnea, it is likely due to suction. At this point, the delivered flow rate and / or oxygen concentration is relatively increased (e.g., up to 70 LPM, 100% oxygen) to compensate for the oxygen gas that would be removed by suction. Figure 66b shows a patient who is initially breathing spontaneously at a set delivery flow. When breathing is suppressed (onset of apnea), the delivered flow increases. As indicated by P1, the pressure sensor 280 records this increase. After a while the pressure begins to drop. If a large suction pressure is used, the pressure can become negative despite the increase in flow rate. This strongly indicates that suction is being used. Then the flow increases again to compensate and P1 returns to a higher level. Alternatively, the delivered flow may increase in proportion to the decrease in airway pressure (i.e., the greater the suction, the more significant the compensation that is initiated). Alternatively, a signal from the suction device may be used to increase the flow rate to a high flow rate at the start of suction.

[0706] Advantages of the suction compensation configuration include the following: · Minimize the suction effect on the patient's oxygen reserve. · The increase in oxygenation starts automatically as soon as suction is detected rather than waiting for initiation by the user. Oxygenation is maximized before intubation.

[0707] Function 4 - Connection to Facilitate Continued Therapy During Transportation · Since current high - flow systems are not easily portable, the ventilatory assistance provided during transportation can be minimal. Instead, typically a low - flow oxygen cannula is attached to the spout of an oxygen cylinder and used. As described above, post - anesthesia patients are at risk of respiratory distress, and low - flow oxygen can result in insufficient assistance. · Current high - flow systems cannot be directly connected to a flow meter such as those on an oxygen cylinder. They may be able to be connected via another tube and a humidifier, but this can be perceived as cumbersome and may require the humidifier to be transported with the patient. · After transportation to the recovery ward, caregivers may not attempt to re - configure the interface, and since this can usually be connected to a wall flow meter via a spout connection, low - flow may be used again. This can also result in insufficient respiratory assistance.

[0708] A configuration suitable for facilitating continued therapy during transportation includes a patient interface for use in a respiratory therapy system, the patient interface comprising a cannula for delivering gas to the patient; a connector portion in fluid communication with the cannula, the connector portion being configured to removably connect the cannula to a complementary connector portion on a main gas conduit for delivering high - flow gas to the cannula; and a secondary conduit in fluid communication with the cannula, the secondary conduit being configured to provide fluid communication between the cannula and an alternative gas source.

[0709] The connector portion in fluid communication with the cannula can be configured to be sealed when the connector portion is detached from the complementary connector portion on the main gas conduit.

[0710] This configuration advantageously enables direct connection of the high-flow interface to the bamboo shoot portion on the flow meter. Since the transport is expected to be of short duration and thus the effect of humidity loss on the patient's condition is negligible, a humidifier is not used.

[0711] Refer to FIG. 67a. The high-flow gas HFG is typically delivered via the main gas conduit 204. When attempting to transport the patient, the cannula tube 202 is disconnected from the main gas conduit 204 and the secondary conduit 280 is connected to the transport gas supply. The secondary conduit may be, for example, a tube. FIG. 67b shows the connection between the cannula 202 and the main gas conduit 204. The main gas conduit 204 and the conduit 202 connected to the cannula have complementary connector portions 202a, 204a. When disconnected, both connector portions 202a, 204a are sealed. The gas supply may be vented back to the high-flow gas source, or there may be some control to turn off the high flow upon disconnection. When the connector portions 202a, 204a are engaged, the cannula connection portion 202a pushes open the gas conduit valve 204b, and the gas flow through the gas conduit 204 opens the valve 202b of the cannula connection portion.

[0712] FIGS. 67d and 67e show the valves at the ends of the secondary gas tube 280. In FIG. 67d, the one-way valve 282 is pushed open by the entry of the gas supply bamboo shoot portion 284 into the connection. FIG. 67e shows the duckbill valve 286. In both cases, they are naturally kept in a closed state by the gas supply when the main gas conduit is connected.

[0713] Alternatively, FIG. 67f shows a usable cap 288 that seals the end of the secondary tube and is removed when the user attempts to connect the secondary tube to the supply gas.

[0714] The crushable conduit or other switching method described above can be a useful option for stopping or preventing gas flow to the patient interface (e.g., using an item such as a crushable block or pad that will come into contact with or be placed in contact with the patient, or that can be attachable or wearable by the patient), but if gas continues to flow through the crushed conduit and it enters the nasal cannula, the pressure within the conduit can increase and ultimately the conduit can rupture or gas can be forced into the crushed portion of the conduit and into the nasal cannula. This can cause undesirable pressure in the patient's lungs or airway.

[0715] As described above, the system can avoid such problems by providing a pressure relief device. However, in addition to or instead of the above-described embodiments, a mask detection mechanism may be particularly useful. For example, when delivering gas flow to a patient's airway using a patient interface, it may be necessary to pay attention to when the path to the patient's airway is utilized by both. For example, when delivering gas flow to the nasal passages using a nasal cannula and when delivering gas flow from the patient's mouth and / or nose to the patient's airway using a mask (and even by providing gas flow in a manner such as creating a seal between the mask and the patient, if the mask is a sealed interface), the likelihood of an overpressure situation can increase. A system that recognizes the dual application of an operating or operable interface may be able to issue a warning for such a situation, or a part of the respiratory system may be actuated or controlled such that both patient interfaces are prevented from simultaneously delivering their respective gas supplies. A system in which such signals are sent or controlled can help minimize or reduce the likelihood that the patient's airway will be accidentally overpressurized. Alternatively, a mask detection mechanism may be used to switch between respiratory modes. For example, a first patient interface may provide a first gas flow to a patient, and when a second patient interface is applied to the patient, the second interface is detected and the first gas flow is prompted to switch off, enabling the second patient interface to provide a second gas flow.

[0716] In some embodiments, a sensor mechanism may be provided, the sensor mechanism including one or more sensors. The one or more sensors may be located on, embedded in, or provided on one or more parts of a patient interface used to deliver gas flow to a patient, or an item associated with such an interface.

[0717] In some embodiments, the respiratory system may include a controller configured to detect the presence of a second patient interface (such as a mask) and notify the user without installing any sensors on the first or second patient interface, and / or adjust high-flow therapy accordingly. For example, the controller may detect a change in pressure, a change in flow rate, or a change in the fan motor speed of the flow generator as a result of placing the mask on the patient. The controller may reduce or discontinue the administration of high-flow therapy in response to a change in pressure, a change in flow rate, or a change in motor speed. Additionally or alternatively, the controller may not...

Claims

Claim 1 A respiratory system for providing respiratory assistance to a patient, comprising: a non-sealed nasal interface; a gas conduit for delivering a gas flow to an inlet of the nasal interface; a flow device including a flow generator configured to generate the gas flow; a pressure sensor for measuring the pressure within the respiratory system; at least one processor for controlling the flow device to deliver the gas flow to the nasal interface at a set flow rate; wherein when the pressure measured by the pressure sensor exceeds a predetermined value, the at least one processor controls the flow device to reduce the flow rate of the gas flow or prevent the gas flow from flowing; the predetermined value varies with the flow rate of the gas flow; A respiratory system characterized by the above. Claim 2. The respiratory system according to claim 1, wherein the relationship between the predetermined value and the flow rate is described by a mathematical equation, a step function, or a look-up table within software possessed by the at least one processor. Claim 3 The pressure sensor is located on the nasal interface, or in the vicinity of the nasal interface, or on the gas conduit, or on a humidifier adapted to humidify the gas flow, or on the flow device. The respiratory system according to claim 1 or 2. Claim 4 The predetermined value is adjustable by the flow device. The respiratory system according to any one of claims 1 to 3. Claim 5 The flow generator includes a blower. The respiratory system according to claim 1. Claim 6 The flow generator includes an auxiliary source of oxygen and / or air. The respiratory system according to claim 1. Claim 7 The respiratory system further includes a crushable portion configured to transition between a first state for providing a gas flow at a first level of flow rate to the inlet and a second state for providing a gas flow at a second level of flow rate to the inlet, the second level being less than the first level. The respiratory system according to claim 1. Claim 8 The first state is an open state, and the second state is a partially or substantially closed state, and the second level of the gas flow is substantially less than the first level or is a gas flow with a substantially zero flow rate. The respiratory system according to claim 7. Claim 9 The crushable portion is provided as part of the gas conduit. The respiratory system according to claim 7 or 8.

10. The nasal interface is a nasal cannula including a side arm, and the side arm includes the crushable portion. The respiratory system according to claim 7 or 8.

11. The crushable portion is adapted to transition from the first state to the second state when (i) a second patient interface for delivering gas flow to the patient is located on the crushable portion, or (ii) a user presses the crushable portion. The respiratory system according to claim 7.

12. The pressure sensor detects the state of the crushable portion. The respiratory system according to claim 7.

13. The respiratory system according to claim 1, further comprising a humidifier adapted to humidify the gas flow. The respiratory system according to claim 1.

14. The respiratory system is configured to deliver gas flow at a flow rate of about 5 or 10 L / min to about 100 L / min, or about 15 L / min to about 95 L / min, or about 20 L / min to about 90 L / min, or about 25 L / min to about 85 L / min, or about 30 L / min to about 80 L / min, or about 35 L / min to about 75 L / min, or about 40 L / min to about 70 L / min, or about 45 L / min to about 65 L / min, or about 50 L / min to about 60 L / min. The respiratory system according to claim 1.

15. The flow device is configured to provide a flow rate of gas flow that achieves a maximum pressure that does not exceed a safety pressure limit. The respiratory system according to claim 1.

16. The gas conduit further includes a conduit heater adapted to heat the gas passing through the gas conduit. The respiratory system according to claim 1.

17. The at least one processor controls the flow device to permit gas flow when the pressure measured by the pressure sensor falls below the predetermined value. The respiratory system according to any one of claims 1 to 16.

18. The flow device includes a user interface operable by a user to set the flow rate and / or concentration of the gas supplied to the nasal interface. The respiratory system according to any one of claims 1 to 17. A flow device including a flow generator configured to generate a gas flow into a non-closed nasal interface, and controlled by at least one processor to deliver the gas flow to the nasal interface at a set flow rate, wherein when the measured pressure received by the at least one processor indicates that the pressure in the nasal interface and / or in the gas conduit for delivering the gas flow to the inlet of the nasal interface exceeds a predetermined value, the at least one processor controls the flow device to reduce the flow rate of the gas flow or prevent the gas flow from flowing, wherein the predetermined value varies with the flow rate of the gas flow, Flow device. Claim 20. The flow device according to claim 19, further comprising a pressure sensor configured to measure the pressure in the flow device and / or the pressure in the nasal interface and / or the pressure in the gas conduit for delivering a gas flow to the inlet of the nasal interface. The flow device according to claim 19.

21. The pressure sensor is located on the nasal interface or in the vicinity of the nasal interface or on the gas conduit or on a humidifier adapted to humidify the gas flow. The flow device according to claim 20.

22. The flow generator includes a blower. The flow device according to claim 19.

23. The flow generator includes an auxiliary source of oxygen and / or air. The flow device according to claim 19.

24. The flow device is configured to deliver a gas flow at a flow rate of from about 5 or 10 L / min to about 100 L / min, or from about 15 L / min to about 95 L / min, or from about 20 L / min to about 90 L / min, or from about 25 L / min to about 85 L / min, or from about 30 L / min to about 80 L / min, or from about 35 L / min to about 75 L / min, or from about 40 L / min to about 70 L / min, or from about 45 L / min to about 65 L / min, or from about 50 L / min to about 60 L / min. The flow device according to claim 19.

25. The flow device is configured to provide a maximum pressure that does not exceed a safe pressure limit. The flow device according to claim 19.

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