Patient interface

Abstract

To provide a cushion module for a patient interface.SOLUTION: The cushion module includes a first cavity, a second cavity, a nasal opening, and an oral opening. The first and second cavities are separated by a cavity wall which, in use, allows breathing gas to flow within the cushion module between the first and second cavities. Further, the first cavity is configured to deliver breathing gas to both the mouth and the nares of a patient via the oral opening and the nasal opening, respectively. The cushion module includes an exhaust vent for directing breathing gas from within the cushion module to an exterior of the cushion module, and the second cavity is in communication with the exhaust vent. Cavity walls and cushion modules are also disclosed.SELECTED DRAWING: Figure 18

Description

[Technical Field]

[0001] The present invention relates to a patient interface for delivering respiratory gas to a patient, and in particular to a non-invasive patient interface. [Background technology]

[0002] One current treatment for obstructive respiratory diseases, such as chronic obstructive pulmonary disease (COPD, including emphysema, refractory asthma, and chronic bronchitis), is noninvasive ventilation (NIV). This therapy involves applying positive airway pressure to the lungs throughout the inhalation-exhalation cycle, thereby widening the airways and improving the flow of respiratory gases into and out of the lungs.

[0003] However, one side effect of the positive pressure applied in current NIV treatments is that it can cause patient discomfort and lead to reluctance to undergo treatment. A subsequent effect of the positive pressure is that the patient interface must be securely fastened to the patient to prevent leakage and thus ensure pressure is maintained within the patient interface and respiratory system. This secure fastening of the interface can lead to pressure sores, especially in semi-conscious or unconscious patients who are therefore unable to provide feedback on the pain caused by the pressure of the patient interface on their skin.

[0004] NIV therapy presents two challenges: compliance (patient compliance) and pressure sores. In addition to these challenges, a further challenge for patients with obstructive respiratory diseases is flushing carbon dioxide from anatomical dead spaces. Specifically, the end of the expiratory cycle is characterized by a drop in the pressure of the exhaled breathing gas. This means that carbon dioxide-laden breathing gas remains in the patient's throat, nose, and mouth and is drawn back into the lungs at the beginning of the inhalation cycle. Patients can be assisted by replacing the carbon dioxide-laden breathing gas in these areas with breathing gas containing oxygen at concentrations appropriate for treating obstructive respiratory diseases. Summary of the Invention [Problem to be solved by the invention]

[0005] It is desirable to provide a patient interface that improves patient comfort and reduces pressure sores.

[0006] It is also desirable to provide a patient interface that assists in flushing anatomical dead spaces. [Means for solving the problem]

[0007] While the invention will be described below by way of a set of embodiments, it will be understood that the invention may be defined exclusively by the features of each embodiment, however, the invention may also be defined by the features of more than one embodiment.

[0008] According to a first aspect, there is provided a non-invasive patient interface having a seal member configured to cover a patient's mouth and nostrils, the interface comprising: (a) a main flow path for delivering breathing gas from a gas source to the mouth and the nostrils separately; (b) a flushing channel for delivering breathing gas from the primary channel and / or gas source to the nostrils; Define the following.

[0009] The primary flow path is a primary flow cavity having one or more primary flow inlets for breathing gas. The device may include a primary flow cavity having one or more primary flow outlets that deliver breathing gas to the mouth and nostrils, respectively.

[0010] The primary flow path may include a primary flow cavity having one or more primary flow inlets for breathing gas and one or more primary flow outlets for delivering breathing gas separately to each of the mouth and nostrils.

[0011] The flushing flow path may include a flushing flow cavity having one or more flushing flow inlets for breathing gas and one or more flushing flow outlets for delivering breathing gas to the patient's nares.

[0012] The interface may include a mask housing, with at least one of the one or more primary flow inlets being within the housing.

[0013] The primary flow cavity may be defined by the seal member and the housing.

[0014] At least one of the one or more primary flow inlets may be formed in the mask housing.

[0015] The patient interface may include one or more of the flushing flow inlets in the seal member.

[0016] The interface may include one or more flushing flow inlets within the mask housing.

[0017] The flushing flow cavity may be a branched cavity having one flushing fluid inlet, two passages downstream of the branch, and respective flushing flow outlets at the downstream ends of each of the passages.

[0018] The flushing flow cavity may be integrally formed with the seal member.

[0019] The flushing flow outlet may be flush with the main flow outlet to the nostril.

[0020] The flushing flow outlet may be recessed into the main flow cavity from one or more main flow outlets to the nostrils.

[0021] The flushing flow cavity may be shaped to direct breathing gases into the nostrils.

[0022] The flushing flow cavity may be shaped to accelerate breathing gas into the nostrils.

[0023] The flushing flow cavity may be defined by a cavity wall extending between one or more flushing flow inlets and one or more flushing flow outlets.

[0024] The flushing flow cavity may be defined by a cavity wall and an outer wall of the seal member.

[0025] The flushing flow cavity may be configured to accelerate the breathing gas. Acceleration of the breathing gas is an increase in the velocity of the breathing gas. Throughout this specification and claims, references to acceleration of the breathing gas are considered to have the same meaning unless otherwise indicated.

[0026] The seal member may have a first main flow outlet defined by a first portion of the mask seal that forms or substantially forms a seal around the patient's mouth, and a second main flow outlet defined by a second portion of the mask seal that forms or substantially forms a seal around the patient's nares.

[0027] The seal member may be of a resilient material and may be connected to the mask housing to form a unitary structure.

[0028] The seal member may be of a resilient material and may be mechanically locked to the mask housing to form a unitary structure.

[0029] The seal member may be overmolded onto the mask housing for mechanically locking with the mask housing.

[0030] The interface may include a mask frame having one or more breathing gas flow channels that allow the flow of breathing gas from a gas source to one or more main flow inlets and one or more flushing flow inlets.

[0031] The mask frame may have a single breathing gas flow channel.

[0032] The mask frame may have separate flow channels for delivering breathing gas to the one or more main flow inlets and separate flow channels for delivering breathing gas to the one or more flushing flow inlets, wherein the one or more flow channels for delivering breathing gas to the one or more flushing flow inlets are configured to accelerate the breathing gas.

[0033] The mask frame may be removably connectable to the mask housing.

[0034] The mask frame may be removably connectable by cooperating snap-fit ​​features on the mask housing and on the mask frame.

[0035] The mask frame may be permanently connectable to the housing by cooperating features on the mask housing and the mask frame.

[0036] The mask frame and housing may be integrally formed.

[0037] The interface includes a vent hole for allowing gases, including exhaled air, to escape from the main flow cavity.

[0038] The vent hole may be in the mask housing.

[0039] The seal member may have one or more main flow outlets that direct breathing gases into the nares and one or more flushing flow outlets that direct breathing gases into the nares, the main flow outlets and the flushing flow outlets being arranged to collectively form nasal openings.

[0040] The cavity wall may extend along the outer wall of the seal member, whereby the flushing flow cavity is defined by the cavity wall and the outer wall.

[0041] The flushing flow cavity may be a single passageway from one or more flushing flow inlets to one or more flushing flow outlets.

[0042] A cavity wall of the flushing flow cavity may separate one or more flushing flow outlets from one or more main flow outlets that direct breathing gases to the nares.

[0043] The flushing flow outlet(s) may have a predetermined shape.

[0044] The cavity wall may include a tether that connects to the rim of the nasal opening and resists deformation of the one or more flushing flow outlets from a predetermined shape.

[0045] The interface includes two flushing flow outlets, which may be separated by a tether such that the flushing flow outlets are substantially aligned with the nostrils.

[0046] The tether may be substantially aligned with the patient's septum in use.

[0047] The predetermined shape may be an hourglass, or a lemniscate, or a hypoped.

[0048] The predetermined shape may be a figure eight.

[0049] The outlet ends of the tether and cavity wall may be flush with the primary flow outlet that directs breathing gas into the nostrils.

[0050] The tether may be recessed within the main flow cavity to avoid contact with the patient when the interface is attached to the patient.

[0051] The cavity walls may be recessed into the main flow cavity to avoid contact with the patient when the interface is attached to the patient.

[0052] The cavity walls may be recessed from the nasal openings to avoid contact with the patient when the interface is worn on the patient.

[0053] The flushing flow cavity may have a high resistance to gas flow compared to the resistance to gas flow of the main flow cavity, and the shape of the flushing flow cavity is selected to accelerate the gas flow sufficiently to cause flushing of the anatomical dead space.

[0054] The mask frame may have a main flow channel and a flushing flow channel that communicate with one or more main flow inlets and one or more flushing flow inlets, respectively.

[0055] The flushing flow channel may have internal dimensions that allow a lower volumetric flow rate of breathing gas than the main flow channel allows at the same temperature and pressure.

[0056] The interface may include a flow distributor having a single inlet connectable to a single gas source and having two outlets connectable respectively to the main flow channel and to a flushing flow channel of the mask frame.

[0057] The one or more main flow inlets and the one or more flushing flow inlets may be in the mask housing.

[0058] The one or more main flow inlets may be in the mask housing and the one or more flushing flow inlets may be in the seal member.

[0059] The flushing flow passage may include a flushing flow cavity having at least one outlet separate from the seal member such that the seal member and the outlet are movable independently of one another.

[0060] The interface may include one main flow inlet and one flushing flow inlet, and the interface further includes a mask frame having a first breathing gas flow channel through which breathing gas can flow from the gas source to the main flow inlet and a second breathing gas flow channel through which breathing gas can flow from the gas source to the flushing flow inlet.

[0061] The flushing flow cavity may be formed as a conduit separate from the seal member, the conduit having a distal end connected to the second breathing gas flow channel and a proximal end terminating at or adjacent to the nasal openings.

[0062] The proximal end of the conduit terminates in a location that can be recessed from the nasal opening.

[0063] The conduit may be surrounded by a main flow cavity.

[0064] The conduit may be formed from a resilient material.

[0065] The conduit may be coupled to the seal member such that the flushing flow outlet follows the nasal opening upon seal deformation.

[0066] The conduit may be connected to the seal member by one or more web members.

[0067] The location and shape of the web member may be selected to substantially retain the flexibility of the seal member without the web member.

[0068] The one or more web members may be coupled to the seal member in a position such that when the seal member is deformed by the patient's nose during fitting or adjustment, the one or more web members apply a force to the conduit.

[0069] One or more web members may connect the proximal end of the conduit to the seal member adjacent or at the rim of the nasal opening.

[0070] One or more web members may extend from a location intermediate the proximal and distal ends of the conduit and connect with the seal member at a location remote from the nasal opening.

[0071] At least one web member may be a partition wall in the plane of symmetry of the seal member.

[0072] The web member or members may have a constant cross section throughout their length.

[0073] One or more of the web members may have a tapered cross section.

[0074] The cross section may taper outwardly from the midpoint of the end towards the end of the web member.

[0075] The seal member may include a flexible region that conforms to the shape of the patient's face and a relatively inflexible structural region that supports the flexible region, with one or more web members connected to the structural region.

[0076] The structural region may coincide with the periphery of the mask frame.

[0077] The structural region may include a portion of the seal member that is attached to the mask housing via overmolding.

[0078] The seal member may include a flexible region that conforms to the shape of the patient's face and a relatively inflexible structural region that supports the flexible region, with one or more web members connected to the flexible region.

[0079] The conduit and the second respiratory gas flow channel may have cooperable features that allow the conduit to be fitted to the second respiratory gas flow channel such that the flushing flow outlets are aligned to direct respiratory gas to the patient's nares when the interface is worn on the patient.

[0080] The cooperable features may include a flange around the outlet of the second breathing gas flow channel and a flange-receiving groove in the inner wall of the conduit.

[0081] The groove may be shaped to limit the extent to which the conduit fits into the second breathing gas flow channel, thereby ensuring proper placement of the conduit to direct breathing gas to the patient's nares when the interface is worn on the patient.

[0082] The shape of the groove may be complementary to the shape of the flange.

[0083] The cooperable features may include a flange portion extending at least partially around the outlet of the second breathing gas channel, a recess adjacent to and distal to the flange, and a flange-receiving groove in the inner wall of the conduit defining an inwardly facing lip, the lip latching into the recess when the flange portion seats in the groove, thereby ensuring proper alignment of the conduit to direct breathing gas to the patient's nares when the interface is worn on the patient.

[0084] The inner wall of the conduit may be flush with the inner wall of the second breathing gas channel at the point where the conduit connects to the second breathing gas channel.

[0085] The conduit may have one or more preferential deformation zones away from the flushing flow outlet to enable the conduit to follow the movement of the nasal opening while substantially maintaining the shape of the flushing flow outlet.

[0086] One or more deformation zones may have a reduced wall thickness compared to the wall thickness of adjacent regions.

[0087] The one or more deformation zones may include bands.

[0088] The band may have a curved profile or a square profile.

[0089] A deformation zone may be formed in the outer wall of the conduit to maintain a low resistance flow path within the flushing flow cavity.

[0090] According to a second aspect, there is provided a non-invasive patient interface having a seal-forming sealing member configured to cover a patient's mouth and nostrils, the interface comprising: (a) a main flow cavity for directing breathing gas from a gas source separately to the mouth and the nostrils; (b) a flushing flow cavity that directs breathing gas from the gas source to the nostrils; , the main flow cavity and the flushing flow cavity being separated by a cavity wall that forms a partition between the inlet to the main flow cavity and the inlet to the flushing flow cavity.

[0091] The main flow cavity may have one or more main flow inlets for breathing gas and may have one or more main flow outlets for delivering breathing gas to the mouth and nostrils, respectively.

[0092] The main flow cavity may have one or more main flow inlets for breathing gas and may have one or more main flow outlets for delivering breathing gas separately to each of the mouth and nostrils.

[0093] The flushing flow cavity may have one or more flushing flow inlets for breathing gas and may have one or more flushing flow outlets for delivering breathing gas to the patient's nares.

[0094] The interface may include a housing, with at least one of the one or more primary flow inlets being within the housing.

[0095] The primary flow cavity may be defined by the seal member and the housing.

[0096] The mask housing includes an opening bounded by a cavity wall to define a main flow inlet and a flushing flow inlet.

[0097] The flushing flow cavity may be integrally formed with the seal member.

[0098] The flushing flow cavity may be shaped to direct breathing gases into the nostrils.

[0099] The flushing flow cavity may have a shape that accelerates the breathing gas as it flows from the flushing flow inlet to the one or more flushing flow outlets.

[0100] The seal member may have a first main flow outlet defined by a first portion of the mask seal that forms or substantially forms a seal around the patient's mouth, and a second main flow outlet defined by a second portion of the mask seal that forms or substantially forms a seal with the patient's nares.

[0101] The flushing flow outlet may be flush with the main flow outlet to the nostril.

[0102] The seal member may be of a resilient material and may be connected to the mask housing to form a unitary structure.

[0103] The seal member may be a resilient material and is mechanically locked to the mask housing to form a unitary structure.

[0104] The seal member may be overmolded onto the mask housing for mechanically locking with the mask housing.

[0105] The interface may include a mask frame having one or more breathing gas flow channels that allow the flow of breathing gas from a gas source to one or more main flow inlets and one or more flushing flow inlets.

[0106] The mask frame may have a single breathing gas flow channel that delivers breathing gas to openings that define the main flow inlet and the flushing flow inlet.

[0107] The mask frame may have separate flow channels for delivering breathing gas to the one or more main flow inlets and the one or more flushing flow inlets, and the one or more flow channels for delivering breathing gas to the one or more flushing flow inlets are configured to accelerate the breathing gas.

[0108] The mask frame may be removably connectable to the mask housing.

[0109] The mask frame may be removably connectable by cooperating snap-fit ​​features on the mask housing and on the mask frame.

[0110] The mask frame may be removably connectable by cooperating features on the mask housing and on the mask frame.

[0111] The mask frame and housing may be integrally formed.

[0112] The interface may include a vent hole for allowing gases, including exhaled air, to escape from the main flow cavity.

[0113] The vent hole may be in the mask housing.

[0114] The interface may include an exhaust cavity that allows exhaled breathing gases to be exhausted outside the interface.

[0115] The exhaust cavity may be defined in part by an exhaust cavity wall that separates the exhaust cavity from the flushing flow cavity.

[0116] The exhaust cavity may be defined by an exhaust cavity wall and an outer wall of the seal member.

[0117] The exhaust cavity may have at least one exhaust gas inlet for receiving exhaled gases from the nostril and may have an exhaust outlet in the seal member for venting the exhaled gases to an exterior of the interface.

[0118] The at least one exhaust gas inlet may be adjacent to the flushing flow outlet.

[0119] At least one exhaust gas inlet may be provided in a wall of the exhaust cavity.

[0120] At least one exhaust gas inlet may be provided in the outer wall adjacent the one or more flushing flow outlets such that the nares are aligned with the at least one exhaust gas inlet and the one or more flushing flow outlets when the interface is worn on a patient.

[0121] According to a third aspect, there is provided a non-invasive patient interface having a seal-forming sealing member configured to cover a patient's mouth and nostrils, the interface comprising: (a) a main flow path for delivering breathing gas from a gas source to the mouth and the nostrils separately; (b) a flushing channel for delivering breathing gas from the primary channel and / or gas source to the nostrils; wherein the primary flow passage includes a primary flow cavity having a primary flow inlet, and the flushing flow passage includes a flushing flow cavity having a flushing flow inlet, the primary flow inlet and the flushing flow inlet being formed by a seal member.

[0122] The primary flow cavity may have one or more primary flow outlets for delivering breathing gas to the mouth and nostrils, respectively.

[0123] The main flow cavity may have one or more main flow outlets for delivering breathing gas separately to each of the mouth and nostrils.

[0124] The flushing flow cavity may have one or more flushing flow outlets for delivering breathing gas to the patient's nares.

[0125] The interface may include a housing secured to the seal member such that a primary flow cavity is defined by the seal member and the housing.

[0126] The flushing flow cavity may be integrally formed with the seal member.

[0127] The flushing flow outlet(s) may be flushed with the primary flow outlet(s) to the nostrils.

[0128] The flushing flow cavity may be shaped to direct breathing gases into the nostrils.

[0129] The flushing flow cavity may be defined by a cavity wall extending between one or more flushing flow inlets and one or more flushing flow outlets.

[0130] The cavity wall may extend along the outer wall of the seal member such that a flushing flow cavity is defined by the cavity wall and the outer wall.

[0131] The flushing flow cavity may be configured to accelerate the breathing gas.

[0132] The seal member may have a first main flow outlet defined by a first portion of the mask seal that forms or substantially forms a seal around the patient's mouth, and a second main flow outlet defined by a second portion of the mask seal that forms or substantially forms a seal with the patient's nares.

[0133] The seal member may be of a resilient material and may be connected to the mask housing to form a unitary structure.

[0134] The seal member may be a resilient material and is mechanically locked to the mask housing to form a unitary structure.

[0135] The seal member may be overmolded onto the mask housing for mechanically locking with the mask housing.

[0136] The interface may include a mask frame having a breathing gas flow channel that allows breathing gas to flow from a gas source to a main flow inlet and a flushing flow inlet.

[0137] The mask frame may be removably connectable to the mask housing.

[0138] The mask frame may be removably connectable by cooperating snap-fit ​​features on the mask housing and on the mask frame.

[0139] The mask frame is secured by cooperating features on the mask housing and on the mask frame. It may be removably connectable.

[0140] The mask frame and housing may be integrally formed.

[0141] The interface may include a vent hole for allowing gases, including exhaled air, to escape from the main flow cavity.

[0142] The vent hole may be in the mask housing.

[0143] The shapes of the main flow cavity and the flushing flow cavity may be selected to provide resistance to gas flow that allows breathing gas to be delivered through the main flow cavity to provide pressure support therapy and delivers breathing gas through the flushing flow cavity to provide flushing of anatomical dead spaces.

[0144] The sealing member may include a nasal opening that is a combination of a flushing flow outlet and a primary flow outlet that delivers breathing gas to the nares, wherein each of these two outlets contributes a cross-sectional area to the overall cross-sectional area of ​​the nasal opening, and the ratio of the cross-sectional area of ​​the flushing flow outlet to the cross-sectional area of ​​the primary flow outlet that delivers breathing gas to the nares is selected to provide a desired resistance to the flow of breathing gas through the primary flow cavity and the flow of breathing gas through the flushing flow cavity.

[0145] The cavity walls may be connected to the seal member such that their proportions do not substantially change when the interface is worn on a patient.

[0146] The cavity wall may be connected to the rim of the nasal opening such that the cavity wall bounds the nasal opening.

[0147] The flushing flow cavity may have a higher resistance to gas flow compared to the resistance to gas flow of the main flow cavity, and the shape of the flushing flow cavity is selected to accelerate the gas flow sufficiently to cause flushing of the anatomical dead space.

[0148] The mask housing may have a generally U-shaped configuration.

[0149] The main flow inlet and the flushing flow inlet may have a combined cross-sectional area that allows a mold tool core used to form the flushing flow cavity and the main flow cavity to be removed through the main flow inlet and the flushing flow inlet when molding the seal member into the mask housing.

[0150] According to a fourth aspect, there is provided a non-invasive patient interface having a seal-forming sealing member configured to cover a patient's mouth and nostrils, the interface comprising: (a) a main flow cavity having one or more main flow inlets for breathing gas and having one or more main flow outlets for separately delivering breathing gas to each of the mouth and nostrils; (b) a flushing flow cavity having one or more flushing flow inlets for breathing gas and having one or more flushing flow outlets for delivering breathing gas to the patient's nares; wherein the primary flow cavity and the flushing flow cavity are separated by a cavity wall, the primary flow outlets to the nostrils and the flushing flow outlets to the nostrils are adjacent to each other, and the cavity wall allows breathing gas from the flushing flow cavity to enter the nostrils. and positioned to allow exhaled gases to exit the nostrils and enter the primary flow cavity.

[0151] The cavity wall includes one or more preferential deformation regions that accommodate deformation of the cavity wall without obstructing the flashing flow cavity.

[0152] In a fifth aspect, there is provided a non-invasive patient interface that forms or substantially forms a seal around a patient's mouth and nostrils, the interface comprising: (a) a main flow cavity having one or more main flow inlets for breathing gas and having one or more main flow outlets for separately delivering breathing gas to each of the mouth and nostrils; (b) a flushing flow cavity having one or more flushing flow inlets for breathing gas and having one or more flushing flow outlets for delivering breathing gas to the patient's nares; wherein the main flow cavity and the flushing flow cavity are separated by a cavity wall, the cavity wall including one or more preferential deformation regions that accommodate deformation of the cavity wall without blocking the flushing flow cavity.

[0153] The interface includes a seal member and a mask housing, and the interface includes one main flow inlet and one flushing flow inlet, both of which may be disposed within the seal member.

[0154] The flushing flow cavity may be integrally formed with the seal member.

[0155] The flushing flow outlet may be flush with the main flow outlet to the nostril.

[0156] The flushing flow cavity may be shaped to direct breathing gas into the nostrils.

[0157] The flushing flow cavity may be defined by a cavity wall extending between one or more flushing flow inlets and one or more flushing flow outlets.

[0158] The cavity wall may extend along the interior of the outer wall of the seal member such that a flushing flow cavity is defined by the cavity wall and the outer wall.

[0159] The flushing flow cavity may be configured to accelerate the breathing gas.

[0160] The seal member may have a first main flow outlet defined by a first portion of the mask seal that forms or substantially forms a seal around the patient's mouth, and a second main flow outlet defined by a second portion of the mask seal that forms or substantially forms a seal with the patient's nares.

[0161] The seal member may be of a resilient material and may be connected to the mask housing to form a unitary structure.

[0162] The seal member may be a resilient material and is mechanically locked to the mask housing to form a unitary structure.

[0163] The seal member may be overmolded onto the mask housing for mechanically locking with the mask housing.

[0164] The interface may include a mask frame having first and second breathing gas flow channels that allow the flow of breathing gas from a gas source to the flushing flow inlet and the main flow inlet, respectively.

[0165] The first respiratory gas flow channel may have a first inlet and the second respiratory gas flow channel may have a second inlet, the cross-sectional areas of the first and second inlets being selected to provide a desired resistance to flow through the first and second respiratory gas flow channels.

[0166] The cross-sectional area of ​​the first inlet can be greater than the cross-sectional area of ​​the second inlet such that the first breathing gas flow channel has a lower resistance to flow than the second breathing gas flow channel.

[0167] The interface may include one or more pressure ports for monitoring pressure within the patient interface.

[0168] The mask frame may be removably connectable to the mask housing.

[0169] The mask frame and housing may be integrally formed.

[0170] The mask frame may be removably connectable by cooperating snap-fit ​​features on the mask housing and on the mask frame.

[0171] The mask frame may be removably connectable by cooperating features on the mask housing and the mask frame.

[0172] The interface may include a vent hole for allowing gases, including exhaled air, to escape from the main flow cavity.

[0173] The vent hole may be in the mask housing.

[0174] The mask seal may have one or more main flow outlets that direct breathing gases into the nares and one or more flushing flow outlets that direct breathing gases into the nares, the main flow outlets and the flushing flow outlets being arranged side-by-side to form nasal openings.

[0175] The flushing flow cavity may be a single passageway from one or more flushing flow inlets to one or more flushing flow outlets.

[0176] A cavity wall of the flushing flow cavity may separate one or more flushing flow outlets from one or more main flow outlets that direct breathing gases to the nares.

[0177] The flushing flow outlet(s) may have a predetermined shape.

[0178] The cavity wall may include a tether that connects to the rim of the nasal opening and holds the one or more flushing flow outlets in a predetermined shape.

[0179] The interface may include two flushing flow outlets separated by a tether such that the flushing flow outlets are aligned with the nostrils.

[0180] The tether may be configured to align with the patient's septum when the mask is in use.

[0181] The seal member may be configured to prevent the cavity wall from contacting the patient.

[0182] The cavity wall may be recessed from the nasal opening.

[0183] The cavity wall may be connected to the rim of the nasal opening and to the sealing member adjacent the rim by a tether that is recessed from the nasal opening to avoid contact with the patient.

[0184] The deformation region may separate one portion of the cavity wall from another portion of the cavity wall such that a force applied to one portion of the cavity wall is not transmitted to the other portion.

[0185] The deformation region may separate one portion of the cavity wall from another portion of the cavity wall so that the two portions can move relative to one another.

[0186] The deformation region may be shaped to roll over a portion of the cavity wall as the two portions of the cavity wall translate relative to one another.

[0187] The deformation region may have a wall thickness that is less than the wall thicknesses of the two portions such that the deformation region is more flexible than each of the two portions.

[0188] The cavity wall may have upper and lower cavity wall portions connected by a deformation region such that the upper cavity wall portion translates relative to the lower cavity wall portion.

[0189] The two portions of the cavity wall may each be shaped to resist deformation due to forces exerted on the seal by engagement with the user's face.

[0190] The upper and lower cavity wall portions may be inclined relative to one another and are connected by a deformation region that allows relative shear movement between the portions.

[0191] The upper cavity wall may be a sloped valley shape with upwardly curving sides, and the lower cavity wall may be a curved wall with rearwardly outwardly curving sides, with a deformation region connecting the upper and lower cavity walls.

[0192] The deformation region may have a curved profile. Optionally, the deformation region may be a U-shaped wall.

[0193] The lower cavity wall may terminate in a rim recessed from the nasal opening such that when a deformation force is applied to the seal member, the tether and deformation region cooperate to hold the rim in a position recessed from the nasal opening.

[0194] The shapes of the upper and lower cavity walls may be selected to avoid blockage of the main flow cavity and the flushing flow cavity as they deform.

[0195] The tether may be recessed from the nasal opening so that the tether does not contact the patient when the interface is applied to the patient.

[0196] The cavity wall may be connected to the rim of the nasal opening such that the nasal opening remains in the same relative position to the rim of the cavity wall.

[0197] The cavity wall is connected to the rim of the nasal opening, providing a flushing flow outlet and a main flow to the nostril. The cross-sectional area of ​​the primary flow outlet may be defined to resist changes in the cross-sectional area of ​​the flushing flow outlet and the primary flow outlet as the seal member deforms.

[0198] The seal member may include a deformation resistance region that converts deformation forces into deformation regions such that deformation of the cavity wall is substantially limited to one or more preferential deformation regions.

[0199] The sealing member may include a bead that surrounds the rim of the nasal opening, the bead being less flexible than the surrounding sealing member and therefore having a wall thickness greater than that of the surrounding sealing member so as to resist obstruction of the nasal opening.

[0200] The tether may be connected to the bead such that deformation forces are transmitted through the bead to the tether, to one or both of the two cavity walls, and then to one or more preferential deformation regions.

[0201] The tether may help resist deformation of the nasal opening.

[0202] According to a sixth aspect there is provided a non-invasive patient interface having a seal-forming sealing member configured to cover the patient's mouth and nostrils, the interface comprising: (a) a main flow cavity for separately delivering breathing gas to the mouth and the nostrils; (b) an exhaust flow cavity for directing exhaled air from the mouth and nostrils and excess breathing gas from the primary flow cavity, or both, to the exterior of the interface; the seal member includes a cavity wall separating the primary flow cavity from the exhaust flow cavity, and includes nasal openings that allow breathing gases to flow into and out of the nares, the cavity wall and nasal openings arranged to allow breathing gases from the primary flow cavity to flow to the nares via the nasal openings, and to allow exhaled breathing gases from the nares, the primary flow cavity, or both to flow to the exhaust cavity via the nasal openings.

[0203] The main flow cavity has one or more main flow inlets for breathing gas and may have one or more first main flow outlets for delivering breathing gas to the mouth and one or more second main flow outlets for delivering breathing gas to the nostrils.

[0204] The seal member may include nasal openings and a mouth opening that allows breathing gases to flow into and out of the mouth via the primary flow cavity.

[0205] The interface may include an exhaust vent for routing exhaled gases and excess respiratory gases from the exhaust flow cavity to a location external to the interface.

[0206] The exhaust vent is used to exhaust breathing gas from the cushion module. The exhaust vent may include a single opening or a group of openings. The terms "vent," "vent hole," "bias vent," "bias vent opening," "vent opening," and "exhaust vent" are used throughout this specification to describe the exhaust vent.

[0207] The patient interface may include a mask housing, the interface including one primary flow inlet and one exhaust flow outlet, both disposed within the seal member.

[0208] The exhaust flow cavity may be integrally formed with the seal member.

[0209] The exhaust flow inlet may be flush with the primary flow outlet to the nostrils.

[0210] The seal member may be a resilient material and may be attached to the mask house to form a unitary structure. The device may be connected to a network.

[0211] The seal member may be of a resilient material and may be mechanically locked to the mask housing to form a unitary structure.

[0212] The seal member may be overmolded onto the mask housing for mechanically locking with the mask housing.

[0213] The interface may include a mask frame that includes an exhaust vent.

[0214] The interface may include one or more pressure ports for monitoring pressure within the interface.

[0215] The mask frame may be removably connected to the mask housing.

[0216] The mask frame may be removably connectable by cooperating snap-fit ​​features on the mask housing and on the mask frame.

[0217] The mask frame may be removably connectable by cooperating features on the mask housing and on the mask frame.

[0218] The seal member may have one or more second primary flow outlets that direct breathing gases into the nares and one or more exhaust flow inlets that receive gas flow from the nares and from the primary flow cavity, the second primary flow outlets and the exhaust flow inlets being adjacent to each other to form nasal openings.

[0219] The seal member may be configured to prevent the cavity wall from contacting the patient.

[0220] The cavity wall may be recessed from the nasal opening.

[0221] The cavity wall may be connected to the rim of the nasal opening and to the sealing member adjacent the rim by a tether that is recessed from the nasal opening to avoid contact with the patient.

[0222] The cavity wall may be recessed from the rim of the nose opening to an extent that allows gases from the main flow cavity to flow into the exhaust flow cavity.

[0223] The cavity walls may be recessed from the rim of the nasal openings to an extent that allows gases from the primary flow cavity to flow into the exhaust flow cavity when the patient interface is in use.

[0224] The nasal opening may include a volume between a rim of the nasal opening and an end of the cavity wall recessed from the rim.

[0225] The cavity wall may include one or more regions of preferential deformation that accommodate deformation of the exhaust flow cavity without obstructing the exhaust flow cavity.

[0226] The deformation region may separate one portion of the cavity wall from another portion of the cavity wall such that a force applied to one portion of the cavity wall is not transmitted to the other portion.

[0227] The deformation region may separate one portion of the cavity wall from another portion of the cavity wall so that the two portions can move relative to one another.

[0228] The two portions of the cavity wall may be shaped to resist deformation.

[0229] The seal member may include a deformation resistant region that converts a deformation force into a deformation region such that deformation of the seal member is substantially limited to the deformation region.

[0230] The sealing member may include a bead that surrounds the rim of the nasal opening, the bead having a wall thickness greater than that of the surrounding sealing member, such that the bead is less flexible than the surrounding sealing member and therefore resists obstruction of the nasal opening.

[0231] The tether may be connected to the bead such that deformation forces are transferred through the bead to the tether, to one or both of the two cavity walls, and then to one or more preferential deformation regions.

[0232] The tether helps resist deformation of the nasal opening.

[0233] The mask frame may cooperate with the seal member to separate the primary flow path from the exhaust flow path.

[0234] The mask frame may include a partition wall cooperable with the cavity wall to separate the primary flow path from the exhaust flow path.

[0235] The mask frame may include a gas inlet opposite or substantially opposite the one or more first primary flow outlets such that the primary flow path is generally straight.

[0236] The mask frame may include a gas inlet positioned relative to the first main flow outlet such that breathing gas undergoes a small (0-5°) change in direction between the gas inlet and the first main flow outlet.

[0237] The mask frame can include a gas inlet positioned relative to the first primary flow outlet such that the primary flow path has low resistance to gas flow. The first primary flow outlet can oppose the gas inlet to define a primary flow path that is substantially straight.

[0238] The cavity wall may contact the mask housing.

[0239] The mask housing may include an exhaust vent, and a cavity wall may be associated with the housing such that the exhaust cavity is in communication with the exhaust vent.

[0240] The cavity wall may contact the mask housing such that the exhaust cavity is in communication with the exhaust vent.

[0241] The exhaust vent may include a series of openings in the cushion modules arranged in groups.

[0242] A series of openings may be provided in the mask housing.

[0243] The cavity wall may contact the mask housing to form a seal separating the exhaust cavity from the main flow cavity.

[0244] The cavity walls may be connected to the mask housing by overmolding the cavity walls with the mask housing.

[0245] The mask housing may include a series of openings through which the cavity walls may be overmolded to connect the cavity walls to the mask housing.

[0246] A series of openings may be disposed between the main flow inlet and the exhaust vent of the mask housing.

[0247] The series of openings may form a U-shaped curve.

[0248] The series of openings may form a curved shape.

[0249] The seal member may be adapted to maintain a spaced apart relationship between the cavity wall and the nasal opening when a deforming force is applied to the seal member.

[0250] The spaced apart relationship may be maintained by interlocking the face-contacting portion of the seal member with the cavity wall.

[0251] The seal member may include a connecting member extending from the face-contacting wall of the seal member to the cavity wall, whereby at least a portion of a deformation force applied to the face-contacting wall is directed to the cavity wall.

[0252] The face-contacting wall of the seal member may be a first wall between the nasal opening and the mouth opening, whereby forces applied to the first wall are transmitted to the cavity wall.

[0253] The face-contacting wall of the seal member may be a second wall of the seal member located between the nasal opening and the exhaust vent, whereby forces applied to the second wall are transmitted to the cavity wall.

[0254] The coupling member may be connected to the first wall along a connecting line.

[0255] The connecting line may comprise at least 10% of the distance of the first wall measured between the nasal opening and the oral opening on the outside of the seal member.

[0256] The connecting line may comprise at least 20% of the distance of the first wall measured between the nasal opening and the oral opening on the outside of the seal member.

[0257] The coupling member may be connected to the second wall along a connecting line.

[0258] The connecting member may be connected to the cavity wall along a connecting line.

[0259] The connecting line or lines may terminate at a position spaced from the rim of the nasal opening or at each position.

[0260] The or each location may be spaced apart from the bead.

[0261] The connecting member may be recessed from the nasal opening.

[0262] The connecting member may be recessed from the nasal opening so as not to contact the bead of the nasal opening.

[0263] The deformation region may be interposed between the first and second elastic regions.

[0264] The deformation region may include first and second elastic regions and a deformation panel disposed between the regions.

[0265] The deformation panel may have a thickness that is less than the thickness of the first and second resilient regions.

[0266] The deforming panel may include a first wall projecting from the first resilient region and a second wall connecting the first wall and the second resilient region.

[0267] The first and second resilient regions of the cavity wall may have a thickness at least three times the thickness of the first wall.

[0268] The second wall may have a curved profile from the first wall to the second elastic region to induce a rolling motion in the second wall to accommodate deformation in the deformation region.

[0269] The second wall may increase in thickness from the first wall to the second elastic region to cause initial folding of the first wall during deformation and subsequent rolling of the second wall beginning at the intersection between the second wall and the first wall.

[0270] The intersection between the second wall and the first wall is configured such that deformation occurs along the intersection.

[0271] The linking member may be connected to the second resilient region to direct a deformation force to the deformation region.

[0272] An imaginary line extending from the intersection between the first elastic region and the first wall may converge at the pivot point with another imaginary line extending along the intersection between the first wall and the second wall.

[0273] The first wall may protrude from the first resilient region to its intersection with the second wall a distance in the range of 1 to 10 mm. The distance may be in the range of 2 to 5 mm. The distance may be 3 mm.

[0274] The second wall may protrude from the second deformation-resistant region by a distance in the range of 2 to 15 mm, and the distance may be in the range of 2 to 10 mm.

[0275] The first resilient region may constitute a first thickened region of the cavity wall.

[0276] The first thickened region may include a rim adjacent the deformation region and an end panel extending from the rim and connected to the mask housing.

[0277] The termination panel may have a thickness at least twice the thickness of the first wall. The termination panel may have a thickness in the range of 0.5 to 3 mm.

[0278] The second resilient region may include a load spreading member attached to the deformation region on a side opposite to the side attached to the first resilient region.

[0279] The load spreading member may constitute a second thickened region of the cavity wall.

[0280] The load spreading member may be formed as a rib along one side of the deformation region and may be connected to the connecting member such that forces applied to the face-contacting wall of the seal member are directed to the deformation region.

[0281] The second elastic region may extend laterally across the cavity wall a distance at least as wide as the nasal opening. Alternatively, the second elastic region may extend across the entire width of the cavity wall.

[0282] The second resilient region may taper to the same thickness of the surrounding cavity wall.

[0283] The second resilient region may be tapered at its lateral ends to the same thickness as the surrounding cavity wall.

[0284] The cavity walls may be configured to direct breathing gases from the primary flow cavity to the nasal openings.

[0285] The cavity wall may include a deflector panel recessed from the rim of the nasal opening and forming a channel for the flow of breathing gas from the main flow cavity to the nasal opening.

[0286] A connecting member may connect the face-contacting wall and the deflector panel to direct forces to the deformation region.

[0287] The deflector panel may abut the second resilient region such that a force applied to the connecting member is transferred to the second deformation-resistant region.

[0288] The deflector panel may connect with an inner wall of the seal member remote from the rim of the nasal opening.

[0289] The deflector panel may connect with the inner wall of the seal member away from the bead that surrounds the rim of the nose opening.

[0290] The main flow inlet of the mask housing may have one or more key features.

[0291] The patient interface may include a socket insert having features complementary to one or more key features on the mask housing to limit rotational movement of the socket insert relative to the mask housing.

[0292] The socket insert may include a connecting portion configured to connect the socket insert with the inlet on the housing and to connect with the outlet portion of the conduit connecting elbow.

[0293] The mask housing may include a headgear connector.

[0294] Alternatively, the patient interface may include a frame that includes a headgear connector.

[0295] The frame may further include a feature configured to interact with a feature on the socket insert to non-rotatably lock the frame relative to the housing when the frame and socket insert are combined with the housing.

[0296] The socket insert may include opposing features capable of holding the frame and housing together therebetween.

[0297] When assembled, the frame and housing are compressed between the features of the socket insert. It can be compressed and held together.

[0298] The frame may include openings configured to align with exhaust vents in the mask housing to allow the escape of breathing gases through the frame to the surrounding environment.

[0299] The frame may be fastened to the mask housing. The frame may be fastened to the housing by gluing or welding.

[0300] The cavity walls may be formed according to the twelfth embodiment.

[0301] The main flow cavity and the exhaust flow cavity may be within a cushion module formed by the seal member and the housing.

[0302] The cavity walls may be positioned relative to the nasal and oral openings of the primary flow cavity to allow breathing gas to flow from the primary flow cavity through the nasal openings and into the nares.

[0303] The cavity walls may be positioned relative to the nasal and oral openings to allow exhaled breathing gases from the mouth and nostrils to flow into the exhaust flow cavity.

[0304] The cavity wall may be recessed relative to the rim of the nasal opening.

[0305] The cavity wall may be positioned relative to the nasal openings such that the main flow cavity and the exhaust flow cavity are in communication with the nasal openings.

[0306] The outlet of the main flow cavity and the inlet of the exhaust flow cavity may communicate with the nose openings.

[0307] The cavity wall may be configured such that the connecting member directs a force applied to the face-contacting wall portion to a deformation region of the cavity wall.

[0308] The exhaust vents may be formed as a series of openings in the mask housing arranged in two or more separate groups.

[0309] In one embodiment, the mask housing includes a cluster or group on each lateral side of the primary flow inlet and includes a series of openings extending for each group.

[0310] The series of openings may be arranged to form a V or U shape for each group.

[0311] The series of openings may form a W-shape.

[0312] According to a seventh aspect, there is provided a mask frame cooperating with a cushion module to form a pressurizable patient interface, the cushion module having a primary flow cavity for delivering respiratory gas to the patient's mouth and nares and an exhaust flow cavity for routing exhaled respiratory gas from the patient interface, the mask frame including a respiratory gas inlet substantially aligned with the primary flow outlet of the cushion module that delivers respiratory gas to the patient's mouth.

[0313] The mask frame may include a divider wall that cooperates with the cushion module to define separate primary and exhaust flow paths through the assembled patient interface.

[0314] The mask frame may further include a vent hole for directing exhaled air from the exhaust cavity to the exterior of the mask frame.

[0315] In an eighth aspect, there is provided a mask frame for a patient interface, the mask frame including first and second respiratory gas flow channels that allow respiratory gas to flow from a gas source to a cushion module of the patient interface; (a) breathing gas flows from a first breathing gas flow channel to a second breathing gas flow channel; or (b) breathing gas flows from the second breathing gas flow channel to the first breathing gas flow channel; or (c) respiratory gas flows from the first respiratory gas flow channel to the second respiratory gas flow channel and from the second respiratory gas flow channel to the first respiratory gas flow channel; The present invention includes a flow switching valve that enables

[0316] The flow diverter valve may operate when the gas pressure in the first breathing gas flow channel or the second breathing gas flow channel exceeds a threshold gas pressure.

[0317] The threshold gas pressure may be the gas pressure in the first respiratory gas flow channel or the second respiratory gas flow channel when there is complete or partial obstruction of the first respiratory gas flow channel, the second respiratory gas flow channel, the flushing flow cavity or the nasal opening.

[0318] The flow diverter valve may include an opening sealed by a resilient cover, the resilience of the resilient cover being selected such that the resilient cover is deformable by gas pressure exceeding a threshold gas pressure so as to allow breathing gas to pass through the opening when the gas pressure exceeds the threshold gas pressure.

[0319] The resilient cover may be a poppet valve.

[0320] The flow diverter valve may be incorporated into a mask frame that includes at least first and second breathing gas flow channels.

[0321] In the alternative, the flow diverter valve may be incorporated into the partition wall of the housing of the patient interface.

[0322] In a ninth aspect, a housing for a patient interface is provided that includes a lateral member having lateral sections that are spaced apart and define an outwardly flared interval on at least one side.

[0323] The housing according to this embodiment may be U-shaped, inverted U-shaped, V-shaped or H-shaped.

[0324] The housing may have a peripheral feature that allows for the securing or connection of a resilient, seal-forming sealing member to form a cushion module incorporating the housing.

[0325] The peripheral feature may include a series of holes sized to allow for the securing or connection of a resilient, seal-forming seal member by overmolding.

[0326] In a tenth aspect, there is provided a patient interface including a cushion module including a housing according to the above disclosed aspects and a resilient, seal-forming sealing member that contacts the patient's face.

[0327] The resilient seal-forming sealing member may be formed according to any of the embodiments disclosed above.

[0328] An eleventh aspect is a cushion module for a patient interface, the cushion module including a first cavity, a second cavity, a nasal opening, and a mouth opening; a. the first and second cavities are separated by a cavity wall that, in use, allows breathing gas to flow within the cushion module between the first and second cavities; b. the first cavity is configured to deliver breathing gas to both the patient's mouth and nostrils via the oral and nasal openings, respectively; c. the cushion module includes an exhaust vent for directing breathing gas from within the cushion module to the exterior of the cushion module; and d. The second cavity provides a cushion module that communicates with the exhaust vent.

[0329] The first cavity may be a main flow cavity and the second cavity may be an exhaust cavity.

[0330] The cushion module may be configured to accelerate breathing gas through the first cavity and into the nares.

[0331] The first cavity may be configured to accelerate breathing gas and direct the accelerated breathing gas towards the nasal openings.

[0332] The first cavity may be configured with a narrowing taper towards the nasal opening.

[0333] A taper may be formed between the cavity wall and a face-contacting wall that may be positioned between the mouth opening and the nasal opening.

[0334] The cavity wall includes a deformation region that deforms preferentially relative to the remainder of the cavity wall when a deformation force is applied to the cavity wall.

[0335] The deformation region includes a deformation panel that may be less resilient than the remainder of the deformation region, such that the deformation panel preferentially deforms when a deformation force is applied to the seal member.

[0336] The deformation region may further include first and second elastic regions between which the deformation panel is disposed, the elastic regions being capable of directing a deformation force to the deformation panel to cause preferential deformation of the deformation panel.

[0337] The deformation of the deformation region may involve a decrease in the spacing between the first and second resilient regions and an associated deformation of the deformation panel to accommodate the decrease in spacing.

[0338] The deforming panel may include first and second walls adapted to deform in a predetermined sequence.

[0339] The predetermined sequence may include the deforming panel rolling on itself.

[0340] The predetermined sequence may include the second wall rolling over the first wall.

[0341] The first wall projects from the first elastic region in a first direction, the second wall projects from the second elastic region in a second direction different from the first direction, and the first wall projects from the second elastic region in a second direction different from the first direction. Interacting with the walls, the predetermined sequence may include a first wall being folded against a first resilient region.

[0342] The second wall may be configured to induce rolling of the second wall over the first wall.

[0343] The second wall may have a curved profile from the first wall to the second resilient region to induce a rolling motion in the second wall.

[0344] The second wall may increase in thickness from the first wall to the second elastic region to cause initial folding of the first wall during deformation and subsequent rolling of the second wall beginning at the intersection between the second wall and the first wall.

[0345] The deformation panel may have a wall thickness selected to induce deformation of the deformation panel in preference to the first and second resilient regions.

[0346] The first and second resilient regions may have a wall thickness that is at least three times the wall thickness of the deformable panel.

[0347] The cushion module may include a housing and a flexible seal member connected to a periphery of the housing, the seal member including the cavity wall.

[0348] The cavity wall may connect with the housing inside the connection between the periphery of the seal member and the periphery of the housing.

[0349] The housing may include an exhaust vent.

[0350] The cavity wall connection with the housing extends at least partially around the exhaust vent.

[0351] The exhaust vent may be bounded by the connection of the cavity wall with the housing and the connection between the perimeter of the seal and the perimeter of the housing.

[0352] The seal member may be adapted to maintain a spaced apart relationship between the cavity wall and the nasal opening when a deforming force is applied to the seal member.

[0353] The spaced apart relationship may include the cavity wall being recessed from the rim of the nasal opening.

[0354] The spaced apart relationship may further include the cavity walls being positioned such that the first and second cavities open to the nasal openings.

[0355] The seal member may be configured to direct at least a portion of the deformation force to the deformation region.

[0356] The cavity wall may be coupled to the face-contacting portion of the seal member to maintain a spaced apart relationship between the cavity wall and the nasal opening when a deforming force is applied to the seal member.

[0357] The seal member may include a connecting member connecting the deformation region to the face-contacting portion of the seal member, such that at least a portion of a deformation force applied to the face-contacting portion is directed to the deformation region.

[0358] The cavity walls may include a deflector panel adjacent the nose opening, a main panel associated with the housing, and a deformation region between the deflector panel and the main panel.

[0359] The deflector panel may be recessed from the rim of the nasal opening, and a connecting member connects the face-contacting wall with the deflector panel to direct deformation forces to the deformation region.

[0360] The exit from the first cavity to the nostril and the entrance to the second cavity may form a nasal opening.

[0361] The first cavity may be a lower cavity and the second cavity may be an upper cavity disposed above the first cavity.

[0362] The nose opening may be in communication with an outlet of the first cavity outlet and an inlet of the second cavity inlet.

[0363] In a twelfth aspect, there is provided a cavity wall for separating first and second cavities within a cushion module of a patient interface, the cavity wall having a deformation region adapted to preferentially deform under a deformation force applied to the cushion module.

[0364] The deformation region may include a deformation panel that deforms under a deformation force.

[0365] The deformation region may further include first and second elastic regions between which the deformation panel is disposed, the elastic regions directing a deformation force to the deformation panel to cause preferential deformation of the deformation panel.

[0366] The deformation of the deformation region may involve a decrease in the spacing between the first and second resilient regions and an associated deformation of the deformation panel to accommodate the decrease in spacing.

[0367] The deforming panel may include first and second walls adapted to deform in a predetermined sequence.

[0368] The first wall protrudes from the first elastic region in a first direction, the second wall protrudes from the second elastic region in a second direction different from the first direction, and the first and second walls have a connection therebetween, and the predetermined sequence can include the first wall being folded against the first elastic region.

[0369] The predetermined sequence may include the second wall buckling to accommodate a decrease in the spacing between the first and second resilient regions.

[0370] The second wall may be configured to induce buckling when the distance between the second resilient region and the connection is less than the length of the second wall.

[0371] The second wall may have a curved profile from the connection to the second resilient region to induce buckling of the second wall.

[0372] The second wall may increase in thickness from the junction to the second elastic region to cause initial folding of the first wall during deformation and subsequent buckling in the second wall.

[0373] The deformation panel may have a wall thickness selected to induce deformation of the deformation panel in preference to the first and second resilient regions.

[0374] The first and second resilient regions have a wall thickness of at least three times the wall thickness of the deformed panel. It may have a certain quality.

[0375] A thirteenth aspect is a non-invasive patient interface configured to deliver pressurized breathing gas to a patient's mouth and nares, the non-invasive patient interface comprising a cushion module having first and second cavities with respective nasal and oral openings configured to deliver breathing gas to the patient's mouth and nares, respectively; (a) the first and second cavities are separated by a cavity wall that, in use, allows breathing gas to flow within the cushion module between the first and second cavities; and (b) providing a non-invasive patient interface, wherein the cavity wall is formed according to the twelfth aspect and configured to direct an external deformation force on the face-contacting portion of the cushion module to the deformation region such that the cavity wall deforms preferentially in the deformation region.

[0376] The first cavity may be adapted to receive breathing gas from a source, and the second cavity may be adapted to exhaust breathing gas from within the cushion module.

[0377] The cavity walls may be positioned relative to the nasal and oral openings to allow breathing gases to flow from the first cavity through the nasal openings to the nares.

[0378] The cavity walls may be positioned relative to the nasal and oral openings to allow exhaled breathing gases from the mouth and nostrils to flow into the second cavity.

[0379] The cavity wall may be recessed relative to the rim of the nasal opening.

[0380] The cavity wall may be positioned relative to the nasal openings such that the first and second cavities are in communication with the nasal openings.

[0381] The outlet of the first cavity and the inlet of the second cavity may be in communication with the nasal openings.

[0382] The cushion module may include a connecting member extending from the face-contacting wall to the cavity wall such that at least a portion of a deformation force applied to the face-contacting wall is directed to the cavity wall.

[0383] The cavity wall may be configured such that the connecting member directs a force applied to the face-contacting wall portion to the deformation region of the cavity wall.

[0384] The coupling member may be connected to the cavity wall along a first connecting line.

[0385] The connecting member may be recessed from the nasal opening.

[0386] The face-contacting wall of the seal member may be a first wall between the nasal opening and the mouth opening, whereby at least a portion of a force applied to the first wall is directed to the cavity wall.

[0387] The coupling member may be connected to the first wall along a second connecting line.

[0388] The second connecting line comprises at least 10% of the distance of the first wall measured between the nasal opening and the oral opening on the outside of the seal member.

[0389] The second connecting line comprises at least 20% of the distance of the first wall measured between the nasal opening and the oral opening on the outside of the seal member.

[0390] The face-contacting wall of the seal member may be a second wall of the seal member located between the nasal opening and the exhaust vent, whereby forces applied to the second wall are transmitted to the cavity wall.

[0391] The coupling member is connected to the second wall along a third connecting line.

[0392] The second and / or third connecting lines may terminate at a position spaced from the rim of the nasal opening or at each position.

[0393] The or each location may be spaced apart from a bead that surrounds the rim of the nasal opening.

[0394] The first cavity may be a lower cavity configured to deliver breathing gas to both the mouth and the nostrils.

[0395] The cushion module may further include an exhaust vent for directing breathing gas from within the cushion module to the exterior of the cushion module.

[0396] The second cavity may be an upper cavity located above the first cavity and may be in communication with an exhaust vent.

[0397] The cushion module may include a housing and a seal member, and the cavity wall connects with the housing.

[0398] The housing may include an exhaust vent.

[0399] The connection of the cavity wall with the housing may at least partially surround the exhaust vent.

[0400] The exhaust vent may be bounded by the connection of the cavity wall with the housing and the connection between the perimeter of the seal and the perimeter of the housing.

[0401] The cavity wall may further include a main panel connecting the housing to the first resilient region.

[0402] The cavity wall may further include a deflector panel recessed from the rim of the nasal opening and forming a channel for the flow of breathing gas from the first cavity to the nasal opening.

[0403] The deflector panel may abut the second resilient region such that a deformation force is directed to the second resilient region.

[0404] The deformation region may be positioned to structurally decouple the deflector panel from the main panel.

[0405] A fourteenth aspect is a non-invasive patient interface configured to deliver pressurized breathing gas to a patient's mouth and nostrils, comprising: (a) a seal for forming a seal around the patient's mouth and nostrils; (b) a housing connected to a seal; (c) the internal volume defined by the seal and housing a cushioning module including: (d) The seal provides a non-invasive patient interface, including cavity walls disposed within the interior volume of the cushion module to define first and second cavities within the interior volume.

[0406] The seal may further include a preferential deformation region that includes a deformation panel.

[0407] The deformation region may further include first and second elastic regions between which the deformation panel is disposed.

[0408] The deformation of the deformation region may involve a decrease in the spacing between the first and second resilient regions and an associated deformation of the deformation panel to accommodate the decrease in spacing.

[0409] The modified panel may include first and second walls and a connection between the first and second walls.

[0410] The first wall may project from the first resilient region in a first direction, and the second wall projects from the second resilient region in a second direction different from the first direction.

[0411] The second direction may be tilted downward from a plane intersecting the second resilient region and the connection portion.

[0412] The connector may have a curved profile that, in a rest state, is aligned with the first direction of the first wall and with an end of the second wall remote from the second resilient region.

[0413] The second wall may have a curved profile from the connection to the second resilient region.

[0414] The second wall may increase in thickness from the junction to the second resilient region.

[0415] The deforming panel may have a wall thickness that is less than the wall thickness of the first and second resilient regions.

[0416] The first and second resilient regions may have a wall thickness that is at least three times the wall thickness of the deformable panel.

[0417] The cavity wall may further include a main panel connecting the housing to the first resilient region.

[0418] The cavity wall may further include a deflector panel recessed from the rim of the nasal opening and forming a channel configured to direct breathing gas from the first cavity to the nasal opening.

[0419] The deflector panel may abut the second resilient region.

[0420] The deformation region may be positioned to structurally decouple the deflector panel from the main panel.

[0421] The cavity walls may be positioned relative to the nasal and oral openings to allow breathing gases to flow from the first cavity through the nasal openings to the nares.

[0422] The cavity walls prevent exhaled breathing gases from the mouth and nostrils from flowing into the second cavity. The nasal and oral openings may be positioned to allow

[0423] The nasal opening may be defined by a rim at the seal, and the cavity wall is recessed relative to the rim within the cushion module.

[0424] The cavity walls may be positioned relative to the nasal openings to allow the first and second cavities to deliver breathing gas to the nasal openings.

[0425] The outlet of the first cavity and the inlet of the second cavity may be in communication with the nasal openings.

[0426] The cushion module may further include (a) a face-contacting wall of the seal; and (b) a connecting member extending from the face-contacting wall to the cavity wall.

[0427] The connecting members may clamp the cavity walls in place against the nasal openings and face-contacting walls.

[0428] The coupling member may be connected to the cavity wall along a first connecting line.

[0429] The connecting member may be recessed from the nasal opening.

[0430] The face-contacting wall may be a first wall between the nasal opening and the mouth opening.

[0431] The coupling member may be connected to the first wall along a second connecting line.

[0432] The second connecting line may comprise at least 10% of the distance of the first wall measured between the nasal opening and the oral opening on the outside of the seal member.

[0433] The second connecting line may comprise at least 20% of the distance of the first wall measured between the nasal opening and the oral opening on the outside of the seal member.

[0434] The face-contacting wall of the seal member may be a second wall of the seal member located on the opposite side of the nasal opening from the face-contacting wall.

[0435] The coupling member may be connected to the second wall along a third connecting line.

[0436] The second and / or third connecting lines may terminate at a position spaced from the rim of the nasal opening or at each position.

[0437] The or each location may be spaced apart from a bead that surrounds the rim of the nasal opening.

[0438] The first cavity may be a lower cavity configured to deliver breathing gas to both the mouth and the nostrils.

[0439] The cushion module may further include an exhaust vent for directing breathing gas from within the cushion module to the exterior of the cushion module.

[0440] The second cavity may be an upper cavity located above the first cavity and may be in communication with an exhaust vent.

[0441] The housing may include an exhaust vent, and the connection of the cavity wall with the housing at least partially surrounds the exhaust vent.

[0442] The exhaust vent may be bounded by the connection of the cavity wall with the housing and the connection between the perimeter of the seal and the perimeter of the housing.

[0443] The exhaust vent may include one or more groups of openings.

[0444] The first cavity may be configured to accelerate breathing gas and direct the accelerated breathing gas to the nasal openings.

[0445] The first cavity may be configured with a narrowing taper towards the nasal opening.

[0446] A patient interface according to either embodiment may be adapted to connect to a flow generator to deliver breathing gas from the flow generator to the cushion module and to transfer breathing gas from the cushion module to the flow generator.

[0447] The patient interface may include an inlet pathway configured to deliver breathing gas to an inlet of the cushion module and an exhaust pathway configured to receive breathing gas from the cushion module, the inlet pathway and the exhaust pathway being coaxial.

[0448] The patient interface may include a coaxial conduit having an inner conduit and an outer conduit surrounding the inner conduit, the inner conduit and outer conduit defining a flow path for breathing gas.

[0449] The inner conduit may define an inlet path and the outer conduit may define an exhaust path.

[0450] The patient interface may further include a mask frame adapted to extend the inlet pathway to the primary flow inlet of the cushion module and adapted to extend the exhaust pathway from the exhaust vent to the outer conduit.

[0451] The mask frame may have an inner duct connecting the inner conduit to the main flow inlet of the cushion module for delivering breathing gas to the main flow cavity, and may also have an outer duct surrounding the inner duct and connecting the exhaust vent to the outer conduit.

[0452] The outer duct may include a mating feature configured to form a seal with the cushion module in an area that overlaps the exhaust vent.

[0453] The connecting feature may be a flange.

[0454] The cushion module includes an overmold where the seal member is overmolded onto the mask housing, and the flange is configured to form a seal against the overmold.

[0455] The patient interface may include a distributor configured to couple the inner conduit to an inspiratory flow conduit of the flow generator and the outer conduit to an expiratory flow conduit of the flow generator.

[0456] The distributor may include one or more interface connections configured to interact with the expiratory flow conduit.

[0457] The patient interface may further include a bias flow vent in the exhaust path configured to exhaust breathing gas to the ambient atmosphere.

[0458] The bias flow vent may be adjustable to vary the flow of breathing gas to the ambient atmosphere.

[0459] The bias flow vent may be configured to discharge 5-15 L / m.

[0460] A bias flow vent may be included in the distributor.

[0461] The bias flow vent may be configured to inhibit connection to a conduit. For example, the bias flow vent may include one or more features that visually indicate that a respiratory conduit should not be connected to the bias flow vent. Alternatively, the one or more features may inhibit a sealing connection with the respiratory conduit to prevent blockage of the bias flow vent.

[0462] Alternatively, the bias flow vent may have a non-standard size or shape to indicate that a respiratory conduit should not be connected to the bias flow vent.

[0463] The bias flow vent may be configured to connect with a filter.

[0464] A patient interface according to either aspect may include an inlet channel configured to deliver breathing gas to a primary flow cavity of the cushion module and an outlet channel configured to receive breathing gas from the cushion module, the inlet channel and outlet channel being configured at least in part as separate channels within a single conduit.

[0465] The outlet channel may receive breathing gas from the exhaust cavity of the cushion module.

[0466] The separate channels may be separated by a common partition wall.

[0467] The separate channels may branch off away from the cushion module end of the frame to form separate conduits.

[0468] A conduit associated with the inlet channel may be connectable with an inspiratory flow conduit of the flow generator, and a conduit associated with the outlet channel may be connectable with an expiratory flow conduit of the flow generator.

[0469] The patient interface may further include a bias flow vent in the exhaust path configured to exhaust breathing gas to the ambient atmosphere.

[0470] The separate flow paths may include multiple openings at the cushion module end of the frame, with a divider wall separating the openings.

[0471] The divider wall may be configured to interact with the cavity wall of the cushion module to form a seal separating the inlet channel from the outlet channel.

[0472] The partition wall may form a cross member that extends across the composite opening of the single conduit, and both the partition wall and the cavity wall may interact with the cross member to form a seal that separates the inlet path from the exhaust path.

[0473] The patient interface may have a mating member extending at least partially around the common opening and configured to couple the single conduit to the cushion module.

[0474] The mating member may be configured to releasably couple the single conduit to the cushion module. do.

[0475] The patient interface may include a headgear connector.

[0476] The mating member may include, in part, a sleeve surrounding the opening in the frame, the sleeve being configured to be coupled to the cushion module. The mating member may further include an end of the single conduit adapted to be coupled to the sleeve.

[0477] The mating members may include friction fit features or interference fit features, or both, for joining the single conduit and sleeve or the sleeve and cushion module.

[0478] A patient interface according to any aspect may include a first conduit configured to deliver breathing gas to a primary flow cavity of the cushion module and a second conduit configured to receive breathing gas from the cushion module, the first and second conduits being spaced apart.

[0479] The first and second conduits may open into the cushion module at locations on opposite sides of the cavity wall.

[0480] The first conduit may be configured to open into the main flow cavity and the second conduit may be configured to open into the exhaust cavity.

[0481] The patient interface may include a mask frame having respective openings through which the first and second conduits pass.

[0482] One or both of the first and second conduits may be connected to the cushion module in a manner that allows limited rotational movement of one or both conduits relative to the cushion module.

[0483] One or both conduits may be connected by a ball joint.

[0484] One or both conduits may include an elbow including a portion shaped as a spherical segment, adapted to mate with the cushion module, and may further include a socket adapted to receive the spherical segment of the elbow to provide limited rotational movement.

[0485] The first and second conduits may be coupled to the cushion module in a fixed orientation.

[0486] The first and second conduits may be coupled to a mask frame in a fixed orientation, and the mask frame may provide respective breathing gas flow paths between the cushion module and the first and second conduits.

[0487] The patient interface may further include a bias flow vent in the second conduit configured to vent breathing gas to the ambient atmosphere.

[0488] According to a fifteenth aspect, there is provided a method of delivering respiratory gas to a patient, comprising: (a) delivering breathing gas at an elevated pressure to a first cavity within a cushion module of a patient interface to supply pressurized breathing gas from the first cavity to the patient's mouth and nares; (b) accelerating the flow of respiratory gas through a portion of the first cavity to deliver the accelerated flow of respiratory gas to the patient's nostrils; A method is provided which includes:

[0489] The method may further include venting breathing gas from a second cavity in the cushion module, the second cavity being in fluid communication with the first cavity.

[0490] While various features are disclosed above in connection with one or more aspects, it will be understood that one or more features of one aspect can be combined with other aspects to achieve additional embodiments. It is understood that the disclosure of a feature in the preceding description should not be construed to mean that the feature applies only to the disclosed aspect. For example, a deformation region may be incorporated into the patient interface of any of the aspects described above. As another example, a flow diverter valve may be incorporated into the patient interface of any of the aspects described above. As a further example, the patient interface housing disclosed above may be incorporated into the patient interface of any one of the previous aspects. As a further example, the seal member disclosed above may be incorporated into the patient interface of any one of the previous aspects.

[0491] Any sequential references (e.g., first, second, third, etc.) to the above-disclosed embodiments merely serve to distinguish the embodiments from one another and should not be construed as an order of importance of the embodiments.

[0492] Aspects of the patient interface disclosed above will now be described in detail with reference to embodiments that serve as examples only and with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0493] [Figure 1] FIG. 1 is a front view of an under-the-nose patient interface with the seal, housing and mask frame showing the normal positions and orientations on the patient interface during use. [Figure 2] FIG. 1 is a perspective front view of an embodiment of a patient interface according to the first aspect disclosed above, including a mask frame; [Figure 3] FIG. 3 is the same view of the patient interface shown in FIG. 2 without the mask frame. [Figure 4] FIG. 2 is a perspective view from above of the rear of the patient interface of FIG. 1; [Figure 5] FIG. 2 is a cross-sectional view of the patient interface of FIG. 1 taken along line AA. [Figure 6] FIG. 10 is a rear perspective view from above of an embodiment of a patient interface according to another embodiment of the first aspect described above. [Figure 7] FIG. 7 is a top view of the seal of the patient interface of FIG. 6 showing the combined respiratory gas outlet to the nares formed by the flushing flow outlet and the main flow outlet to the nares. [Figure 8] FIG. 7 is a cross-sectional side view of the patient interface of FIG. 6 taken along line AA, with arrows indicating the main and flushing flow paths. [Figure 9] FIG. 9 is a rear perspective view of the cross section shown in FIG. 8 without the arrow. [Figure 10] FIG. 10 is a rear perspective view from above of an embodiment of a patient interface without a mask frame according to the second aspect described above. [Figure 11] FIG. 11 is a perspective cross-sectional view of the patient interface of FIG. [Figure 12] FIG. 12 is a side view of the cross section shown in FIG. 11 with arrows indicating the flushing flow path, the main flow path, and the exhaust flow path. [Figure 13] FIG. 11 is a front perspective view of the patient interface shown in FIG. [Figure 14] FIG. 10 is a perspective side view of an embodiment of a patient interface according to the third aspect disclosed above, without a mask frame. [Figure 15] FIG. 15 is a top perspective view of the rear of the patient interface of FIG. [Figure 16] FIG. 15 is a front, slightly inferior perspective view of the patient interface of FIG. 14. [Figure 17] FIG. 15 is a perspective side view of the patient interface shown in FIG. 14 with a mask frame. [Figure 18] FIG. 18 is a cross-sectional view of the patient interface of FIG. 17 taken along line AA, with arrows indicating the flushing and main flow paths. [Figures 19A-19B] 19A-19C are front plan and rear perspective views of the housing shown in the mask of FIGS. 14-18 according to an embodiment of the ninth aspect described above. [Figure 20A] FIG. 2 is a cross-sectional view of a patient interface according to an embodiment of the first aspect disclosed above. [Figure 20B] FIG. 20B is an enlarged view of a portion of the cross section of FIG. 20A showing the configuration of the seal around the flushing flow outlet to the nostril and the main flow channel outlet. [Figure 21] FIG. 20B is a side cross-sectional view of the patient interface of FIG. 20A, with arrows indicating the flushing and main flow paths. [Figures 22A-22D] 10 shows different sealing configurations around the flushing flow outlets to the nostrils and the main flow channel outlet. [Figure 23] FIG. 20B is a side view of the patient interface of FIG. 20A. [Figures 24A-24D] FIG. 24 is a cross-sectional view taken along line AA in FIG. 23. [Figure 25] FIG. 10 is a front view of another embodiment of a patient interface according to the first aspect disclosed above. [Figure 26] FIG. 26 is a cross-sectional view taken along line AA in FIG. 25. [Figure 27]FIG. 26 is a cross-sectional view taken along line AA in FIG. 25, with arrows indicating the flushing path and main flow path. [Figure 28A] FIG. 28 is a perspective view of the inlet end of the conduit of the patient interface of FIGS. 26 and 27; [Figure 28B] FIG. 28B is a cross-sectional view of the conduit of FIG. 28A. [Figures 29A-29B] 10A and 10B are perspective and cross-sectional views, respectively, of an alternative flushing flow channel. [Figures 29C-29D] 10A and 10B are perspective and cross-sectional views, respectively, of a further alternative flushing flow channel; [Figure 30] FIG. 10 is a perspective side view of an embodiment of a patient interface according to the fourth and fifth aspects disclosed above, without the mask frame, with arrows indicating the flushing flow and main flow inlets within the seal; [Figure 31] FIG. 31 is a perspective view from above of the rear of the patient interface of FIG. 30, with arrows indicating the flushing flow and main flow outlets. [Figure 32] 31 is a cross-section of the patient interface of FIG. 30 taken along line AA. [Figure 33] FIG. 33 is the same cross section as FIG. 32 but from a slightly lower perspective of the patient interface. [Figure 34] FIG. 33 is a perspective view from below of the cross section of FIG. 32 without the arrow. [Figure 35] FIG. 31 is a cross-sectional top view taken along line BB in FIG. 30. [Fig. 35B-35C] 31 are perspective rear views from above of the cross-sections taken along lines BB and CC of FIG. 30, respectively. [Figure 36] FIG. 31 is a perspective view of the patient interface of FIG. 30 with an embodiment of a mask frame according to the eighth aspect disclosed above. [Figure 37] FIG. 37 is a cross-sectional view of the patient interface of FIG. 36 taken along line AA, with arrows indicating the flushing and main flow paths through the patient interface. [Figure 38] FIG. 38 is a bottom view of the mask frame of FIGS. 36 and 37. [Figure 39]FIG. 39 is a cross-sectional perspective view of the mask frame of FIG. 38. [Figure 40] FIG. 40 is a perspective view of the mask frame of FIG. 39 without the pressure relief valve. [Figure 41A-41B] 41A and 41B are cross-sectional views of the mask frame of FIG. 40 with the pressure relief valve closed and open, respectively. [Figure 42A-42B] FIG. 38 is a schematic cross-sectional view of the patient interface of FIG. 37 as it would be worn by a patient, illustrating the flow path of respiratory gases during the inhalation and exhalation phases of the breathing cycle as the patient inhales and exhales through the nostrils. [Figure 43] FIG. 10 is a perspective side view of an embodiment of a patient interface according to the sixth and seventh aspects disclosed above. [Figure 44] FIG. 44 is a cross-sectional view of the patient interface of FIG. 43 taken along line AA. [Figure 45] FIG. 44 is a schematic cross-sectional view of the patient interface of FIG. 43 when worn on a patient, with arrows indicating the flow of respiratory gas and the flushing of anatomical dead spaces during exhalation through the nose with the mouth open. [Figure 46] FIG. 44 is a schematic cross-sectional view of the patient interface of FIG. 43 when worn on a patient, with arrows indicating the flow of respiratory gas and the flushing of anatomical dead spaces during exhalation through the nose when the mouth is closed (although the drawing shows the mouth as open, the drawing is to be interpreted as the mouth being closed). [Figure 47] FIG. 44 is a schematic cross-sectional view of the patient interface of FIG. 43 when worn on a patient, with arrows indicating the flow of respiratory gas and the flushing of anatomical dead spaces during exhalation through the mouth. [Figure 48] FIG. 44 is a perspective front view of the mask frame of the patient interface of FIG. [Figure 49] FIG. 44 is a perspective rear view of the mask frame on the patient interface of FIG. [Figure 50] FIG. 10 is a perspective front view of an embodiment of a patient interface according to the sixth aspect disclosed above. [Figure 51]FIG. 51 is a front view of the patient interface shown in FIG. 50. [Figure 52] FIG. 51 is a rear view of the patient interface shown in FIG. 50. [Figure 53] FIG. 51 is an exploded perspective front view of the patient interface shown in FIG. 50. [Figure 54] FIG. 52 is a cross-sectional view of the patient interface shown in FIG. 51 taken along line AA. [Figure 55] FIG. 52 is an enlarged front perspective view of a cross section of the seal only from the patient interface shown in FIG. 51 along line BB. [Figure 56] FIG. 52 is an enlarged top perspective view of a cross section of the patient interface shown in FIG. 51 taken along line CC. [Figure 57] FIG. 56 is a rear perspective view of a seal cross section of the patient interface shown in FIG. 55; [Figure 58] FIG. 52 is an enlarged cross-section of the seal and housing taken along line AA of the patient interface shown in FIG. 51. [Figures 59A-59C] 52A-52C are sequential cross-sectional views of the patient interface shown in FIG. 51 taken along line AA showing how the deformation zone deforms. [Figure 60] FIG. 62 is a perspective top view of a cross section of the seal of FIG. 61 taken along line DD. [Figure 61] FIG. 54 is a front view of a cushion module from the patient interface of FIGS. 50-53. [Figure 62] FIG. 62 is a front perspective view of the cushion module of FIG. 61. [Figure 63] FIG. 63 is a front view of a housing forming part of the cushion module shown in FIGS. 61 and 62. [Figure 64] FIG. 64 is a rear view of the housing shown in FIG. 63. [Figure 65] FIG. 64 is a cross-sectional view of the housing of FIG. 63 taken along line EE. [Figure 66] FIG. 54 is a front view of a frame forming part of the patient interface shown in FIGS. 50-53. [Figure 67] FIG. 67 is a rear view of the frame shown in FIG. 66. [Figure 68]FIG. 67 is a cross-sectional view of the frame of FIG. 66 taken along line FF. [Figure 69] FIG. 54 is a rear perspective view of a socket insert forming part of the patient interface shown in FIGS. 50-53. [Figure 70] FIG. 54 is a front perspective view of a socket insert forming part of the patient interface shown in FIGS. 50-53. [Figure 71] 10 shows another embodiment of a cushion module of a patient interface according to the sixth aspect described above. [Figure 72] FIG. 72 is a perspective top view of a cross section of only the seal of FIG. 71 taken along line HH. [Figure 73] FIG. 72 is a front view of a housing forming a part of the cushion module shown in FIG. 71. [Figure 74] FIG. 72 is a rear view of the housing shown in FIG. 71. [Figure 75] FIG. 75 is a front view of a frame cooperating with the cushion module and housing shown in FIGS. 71-74. [Figure 76] FIG. 63 is a front perspective view of the cushion module shown in FIGS. 61 and 62 with a coaxial dual limb assembly. [Figure 77] FIG. 77 is a rear view of a coaxial frame forming part of the coaxial assembly shown in FIG. 76. [Figure 78] A cross-sectional view of the coaxial assembly shown in Figure 76 taken along line JJ. [Figure 79] FIG. 79 is a perspective view of the top of the coaxial assembly shown in cross section in FIG. 78 when coupled to the cushion module shown in FIGS. 61 and 62 by the socket insert shown in FIGS. 69 and 70. [Figure 80] FIG. 79 is a perspective view of the lower portion of the coaxial assembly shown in cross section in FIG. 78. [Figure 81] FIG. 77 is a perspective view of a coaxial conduit connector forming part of the coaxial assembly shown in FIG. 76. [Figure 82] FIG. 35 is a front perspective view of the cushion module shown in FIGS. 30-34 with an alternative dual limb assembly. [Figure 83]FIG. 83 is a rear view of the dual limb assembly shown in FIG. 82. [Figure 84] 83 is a perspective view of the dual limb assembly and cushion module shown in FIG. 82 when coupled, taken in cross section along line KK of FIG. 82. [Figure 85] 83 is a cross-section of the dual limb assembly and cushion module shown in FIG. 82 when coupled, taken along line KK in FIG. 82. [Figure 86] FIG. 63 is a perspective front view of a patient interface including an alternative dual limb assembly coupled to the cushion module shown in FIGS. 61 and 62. [Figure 87] 87 is a cross-section of the patient interface of FIG. 86 taken along line LL. DETAILED DESCRIPTION OF THE INVENTION

[0494] Preferred embodiments of the present invention will now be described in the following text, including reference numerals that correspond to features shown in the accompanying drawings. Where possible, the same reference numerals are used to identify identical or substantially similar features in different embodiments. However, to maintain clarity of the drawings, not all reference numerals are included in every figure.

[0495] Aspects of the patient interface disclosed above are described in detail below with reference to an embodiment of a patient interface in the general form shown in Figure 1. The embodiments described below are variations on that general form. However, it will be understood that the scope of the aspects should not be limited by reference to that general form or the specific embodiments described below, but instead the aspects should be interpreted as relating to other forms of patient interfaces that also deliver pressurized breathing gas to a patient, including patient interfaces that extend across the bridge of the nose, full-face masks, and full-head helmets.

[0496] Some cross-sectional views of the patient interface include arrows indicating the flow of respiratory gas through the patient interface. The arrows should not be interpreted as vectors, i.e., the magnitude of the arrow should not be interpreted as indicating the volumetric flow rate, velocity, or pressure of respiratory gas at the location of the arrow. The arrows are only a rough indication of the direction of respiratory gas flow at the location of the arrow.

[0497] As used herein, the term "respiratory gas" is intended to mean the gas used in human respiration. As used herein, the term "inhaled respiratory gas" is intended to mean the respiratory gas that is inhaled during the inspiratory phase of the respiratory cycle. This term refers to any respiratory gas that is inhaled during the inspiratory phase of the respiratory cycle, such as ambient air or a gas that has a higher humidity or oxygen level, or both, than ambient air, for the treatment of a patient. The term "exhaled breathing gas" as used herein is intended to mean breathing gas that is exhaled from a patient's lungs and airways. It therefore includes breathing gas from the lungs that occupies the anatomical dead space at the end of the expiratory phase of the respiratory cycle.

[0498] 1, a common configuration includes a patient interface 10 in the form of an under-the-nose mask 10 including a cushion module 20 including a resilient seal member 12 and a housing 50, the mask 10 further including a mask frame 70 connecting to the cushion module 20. The cushion module 20 includes a nasal portion and an oral portion. A conduit from a gas source, such as a humidifier or ventilator, is connected to the mask frame 70 to deliver respiratory gas to the mask 10.

[0499] The mask frame 70 includes a central body portion 72 that includes one or more conduits for carrying breathing gas from a gas source to the cushion module 20 and, therefore, to the patient. The mask frame 70 includes side wings 74 extending from the central body portion 72. Each side wing 74 includes a pair of connectors in the form of bars 76 that are positioned to cooperate with headgear (e.g., elastic straps) to pull the mask 10 into contact with the patient's face and form a substantially airtight seal when breathing gas at elevated pressure is delivered through the mask 10 to the patient.

[0500] Referring to the above discussion of variations on the general form shown in Figure 1, one such variation on the general form that is applicable to the aspects and embodiments described below is one in which the housing and mask frame are integrally formed. In other words, the interface may include a one-piece structure that performs the same function as the housing and mask frame described in the aspects and embodiments below. For this reason, although the aspects and embodiments below describe the housing and mask frame as separate components of the patient interface, this description should be read to include the option of integrally formed components that perform similar functions as the housing and mask frame.

[0501] An embodiment of a mask 10 according to the first aspect is shown in FIGS.

[0502] In this embodiment, the mask frame 70 includes a flushing flow channel 84 having a flushing flow channel inlet 78 and a flushing flow channel outlet 86. The flushing flow channel 84 tapers from the inlet 78 to the outlet 86 such that a supply of breathing gas at a constant pressure is accelerated through the flushing flow channel 84, resulting in a higher flow rate at the outlet 86 than at the inlet 78.

[0503] The mask frame 70 also includes a primary flow channel 82 having a primary flow channel inlet 80 and a primary flow channel outlet 88. The outlet end of the primary flow channel 82 is formed by a sleeve 90, which includes a circumferentially disposed groove feature 92 on its outer wall for cooperating with a further sleeve 56 that defines the opening 54 of the housing 50. The sleeve 56 includes snap-fit ​​features on its radially inner wall that are cooperable with the snap-fit ​​features 92 of the sleeve 90 to form a snap-fit ​​connection therebetween. The cooperable snap-fit ​​features 92 and 58 may provide a permanent connection between the mask frame 70 and the housing 50. Alternatively, the cooperable snap-fit ​​features 92 and 58 may provide a releasable connection between the mask frame 70 and the housing 50, thereby allowing disassembly for replacement and cleaning of parts of the mask 10.

[0504] The housing 50 is formed of a substantially rigid plastic material and has a chassis for supporting or adding structural support to the cushion module 20. The opening 54 is sized and shaped to receive the sleeve 90 of the mask frame 70; in the illustrated embodiment, the sleeve 56 and the sleeve 90 have corresponding non-circular profiles such that the mask frame 70 and the housing 50 cannot be attached to one another unless they are properly aligned. In this manner, the mask frame 70 is properly aligned with the housing 50 such that the flushing flow channel outlet 86 is received within the flushing flow cavity inlet 32, allowing communication of breathing gas from the flushing flow channel 84 to the flushing flow cavity 28 provided in the seal member.

[0505] In an alternative embodiment, sleeve 56 is configured to fit within sleeve 90 of mask frame 70. Sleeve 56 and sleeve 90 also have corresponding non-circular profiles in this embodiment to ensure proper alignment of mask frame 70 and housing 50 before they can be attached to one another.

[0506] The housing further includes two groups of vent openings 52 located below and slightly to the side of opening 54. Vent openings 52 allow exhaled breathing gases to exit mask 10. A further embodiment of the housing includes a single set of vent openings 52.

[0507] The housing 50 includes a series of outwardly projecting tab members 60 around its periphery, as seen in cross section in FIG. 5 . The outer ends of the tab members 60 are connected to a bead 62 that runs continuously across all of the tab members 60, thereby forming a series of discrete windows directly inside the periphery of the housing 50. The seal member 12 is formed integrally with the housing 50 by overmolding a resilient material onto the housing 50 so that the resilient material fills the series of windows. The tab members 60 and bead 62 thus become embedded in the resilient material and are mechanically interlocked with the seal member 12. The seal member 12 and housing 50 thus form the structure of the one-piece cushioning module 20.

[0508] The seal member 12 is formed of a soft, resilient material and includes an oral opening 24 that circumscribes the patient's mouth when the mask 10 is placed on the patient, and a nasal opening 26 located in the valley of the nasal cradle 22 and positioned to contact the underside of the patient's nose. The nasal opening 24 is specifically positioned to align with the patient's nares when the mask 10 is placed on the patient, allowing pressure therapy to be administered through the nares. The seal member 12 further includes a flushing flow cavity 28. The flushing flow cavity 28 is integrally formed with the seal member 12. More specifically, the flushing flow cavity 28 is formed in part in the region of the nasal cradle 22. In this particular embodiment, the flushing flow cavity is formed in part by a cavity wall 34 and in part by the wall of the seal member 12 in the region of the nasal cradle 22.

[0509] In this embodiment, the cavity wall 34 has a single inlet 32 ​​that communicates with the flushing flow channel outlet 86 of the mask frame 70 and is formed to provide a bifurcated flushing flow cavity 28 with two flushing flow outlets 30 (FIG. 4). The flushing flow outlets 30 are flushed flushing flow cavity 28 flushing flow channel outlets 86 are flushing flow channel outlets 86. The flushing flow outlets 30 are flushed flushing flow cavity 28 flushing flow channel outlets 86 are flushing flow channel outlets 86. The flushing flow cavity 28 flushing flow channel outlets 86 are flushing flow channel outlets 86. The flushing flow cavity 28 is also formed to have a cross-sectional area that tapers downward to further accelerate the flushing flow of respiratory gas from the inlet to the outlet end of the flushing flow cavity 28. The flushing flow cavity 28 is formed flushing flow cavity 28 flushing flow channel outlets 86. The flushing flow outlets 30 are flushing flow channel outlets 86. The flushing flow cavity 28 is formed flushing flow cavity 28 ...

[0510] The seal member 12 and the housing 50 are connected to the first and second cavities (referred to herein as the The primary flow channels 82 collectively define an interior volume including a primary flow cavity 36 and a flushing flow cavity 28 (referred to as the primary flow cavity 36 and the flushing flow cavity 28, respectively). Breathing gas delivered via the primary flow channel 82 flows into the primary flow cavity 36, where it is inhaled by the patient via the mouth openings 24 and / or nasal openings 26. Simultaneously, breathing gas is delivered via the flushing flow channel 84 to the flushing flow cavity 28 and then delivered to the patient's nares via the flushing flow outlets 30.

[0511] During operation, the patient is provided with a sufficient amount of breathing gas through the primary flow cavity 36 to meet their tidal flow requirement during the inhalation phase. Simultaneously, a flushing flow stream of breathing gas is provided through the flushing flow cavity 28 and can contribute to the patient's required tidal volume of breathing gas. The tidal flow is provided while maintaining a pressure above atmospheric pressure at the interface and the patient's lungs. Nevertheless, breathing gas provided through the primary flow path is generally inhaled through the mouth via the mouth opening 24 or the nose via the nasal openings 26, or sometimes both. During exhalation, the gas pressure of the exhaled breathing gas through the nares may exceed the gas pressure of the flushing flow, during which time the exhaled breathing gas enters the primary flow cavity 36 through either the mouth opening 24 or the nasal openings 26 and is exhausted to the exterior of the mask through the vent openings 52. While not wishing to be bound by this theory, Applicant believes that as the gas pressure of the exhaled breathing gas through the nostrils decreases toward the end of the expiratory phase, the gas pressure of the flushing flow exceeds the gas pressure of the exhaled breathing gas through the nostrils at some point in the breathing cycle, at which point the flushing flow of fresh breathing gas begins to flow through the nostrils. The same is believed to be true when a patient breathes through both their mouth and nose. However, when a patient breathes only through their mouth, flushing occurs throughout the entire expiratory cycle.

[0512] While not wishing to be bound by this theory, applicants believe that the faster flushing flow of breathing gas into the nostrils flushes out any remaining exhaled breathing gas from the patient's nasal passages, throat, and mouth at the end of the breathing cycle when the air pressure from the exhaled breath tapers off. The nasal passages, throat, and mouth can collectively be referred to as the patient's anatomical dead space. The flushing flow forces exhaled breathing gas into the primary flow cavity 636, where it is exhausted to the exterior of the mask 10 via the vent openings 52. Applicants believe that such flushing increases overall oxygen uptake during the following inhalation phase of the breathing cycle by reducing rebreathing of exhaled breathing gas. The increased oxygen uptake resulting from the flushing of the anatomical dead space is believed to improve the patient's breathing. In other words, the above-described treatment is believed to make breathing easier and more effective for patients suffering from obstructive respiratory disorders.

[0513] Applicant also believes that this dual-cavity patient interface, which accelerates one stream of breathing gas into the nostrils to cause flushing of anatomical dead spaces, allows the treatment therapy pressure applied through the patient interface 10 to be lower than the gas pressure applied through a typical patient interface during typical NIV therapy for equivalent oxygen exchange due to the improved respiratory effectiveness resulting from reduced exhaled air rebreathing. This means that the patient can experience the same gas exchange at a relatively lower therapy pressure. Operating at a lower gas pressure than that used in existing NIV therapy may significantly improve the effectiveness of treating obstructive respiratory disorders, as the lower gas pressure reduces compliance issues and also reduces the incidence of pressure sores. Alternatively, patient interfaces according to embodiments disclosed herein may be used to enable higher oxygen exchange at the same NIV treatment pressure, thereby enabling better patient treatment.

[0514] In a variation of this embodiment, the flushing channel inlet 78 and the main channel inlet 80 are The patient interface 10 may be combined into a single inlet in the mask frame 70. A divider located downstream of the single inlet designates the point at which the mask frame 70 separates into separate flushing flow channels 84 and main flow channels 82. An advantage of this variation is that the patient interface 10 can be coupled to a single source of respiratory gas, such as a ventilator, flow generator, wall source of pressurized air, or CPAP machine, that provides a single flow of respiratory gas. An additional advantage is that only a single conduit needs to be connected to the patient interface, thereby reducing the apparent bulk of the therapy system.

[0515] In this specification and claims, the term "flow generator" is deemed to include flow generators, ventilators, CPAP devices, bi-PAP devices, VPAP devices and wall sources of breathing gas.

[0516] An embodiment of a mask 110 according to the second aspect is shown in Figures 6 to 9. In those figures, features that are the same as or similar to corresponding features in the first embodiment described above are designated with like reference numerals preceded by the numeral "1."

[0517] Mask 110 defines first and second cavities in the form of a primary flow cavity 136 and a flushing flow cavity 128, respectively. Mask 110 differs from mask 10 in that, instead of bifurcated flushing flow cavities, flushing flow cavity 128 is formed as a single passageway from a flushing flow cavity inlet 132 to a single flushing flow cavity outlet 130. As shown in FIGS. 6 and 7 , outlet 130 is defined in part by a distal portion of rim 138 and in part by a cavity wall 134 that terminates flush with nasal openings 126. The periphery of nasal openings 126 is defined in part by cavity wall 134 and in part by a proximal portion of rim 138. Outlet 130 and nasal openings 126 together form a combined breathing gas opening that is positioned in seal member 112 so as to align with the nares when mask 10 is worn on a patient.

[0518] Similar to mask 10, the cavity walls 134 of mask 110 are shaped toward the outlets 30 so that breathing gases are directed upward into the patient's nares. This is provided by the cavity walls 134 being sloped upward toward the outlets 130 in the portion of the cavity walls 134 directly upstream of the outlets 130.

[0519] The cavity wall 134 and the distal portion of the rim 138 together provide the outlet 130 with a constricted waist shape, such as a lemniscate, hypoped, figure-eight, or hourglass shape. This shape is specifically provided by a tether 140 that extends between opposite sides of the lateral midpoint of the outlet 130. The tether 140 is flush with the nasal openings 126. Furthermore, its position means that it generally coincides with the nasal septum when the mask 110 is worn on a patient.

[0520] Tether 140 is integrally formed with seal member 112 and therefore comprises the same resilient material. It will be appreciated that tether 140 reduces the extent to which outlet 130 is obstructed as mask 110 conforms to the contours of the patient's face. In other words, tether 140 reduces the extent to which cavity wall 134 collapses toward the distal portion of rim 138, reducing the area of ​​outlet 130. It also reduces the extent to which cavity wall 134 collapses toward the proximal portion of rim 138, reducing the area of ​​nasal openings 126. If either occurred, the effectiveness of mask 110 in flushing anatomical dead spaces and allowing inhalation through the nares would be reduced.

[0521] The tether 140 also counteracts the balloon effect of the outlet 130 caused by increased breathing gas pressure. The increased gas pressure pressurizes the cavity walls at the outlet 130. Without tether 140, the shape of the outlet would not be maintained because of the force that would be exerted on the outlet 130 away from 138. This means that the acceleration effect on the breathing gas created by the shape of the outlet 130 and the shape of the flushing flow cavity leading to the outlet 130 may be reduced.

[0522] In an alternative embodiment, the tether 140 may be recessed into the flushing flow cavity 128 to avoid contact with the patient when the mask 110 is placed on the patient.

[0523] It will be appreciated that the flushing flow cavity 128 may be partitioned toward its outlet end to form adjacent outlets 130 that operate in substantially the same manner as the single outlet described above. In this variation, the partition may include a tether 140.

[0524] As with mask 10, the flushing channel inlet 178 and the main channel inlet may be connected to separate breathing gas sources. However, in this variation of mask 110, both may be connected to a single breathing gas source by either a branch connection or any suitable form of path-splitting connection that allows one conduit to branch into two conduits.

[0525] In a further alternative variation, flushing flow cavity inlet 132 may be positioned within housing 150 such that both main flow channel 182 and flushing flow channel 184 route breathing gas through housing 152 to respective main flow cavity 136 and flushing flow cavity 128. In each case, channels 182 and 184 sealingly connect with housing 150 and / or seal member 120 such that pressurized breathing gas can flow through channels 182 and 184 to main flow cavity 136 and flushing flow cavity 128.

[0526] In the first and second aspect embodiments described above, one advantage of integrating the flushing flow conduit and flushing flow outlet with the seal member is that as the seal member deforms to fit the patient's facial features, for example, when initially donned or adjusted, the flushing flow cavity, and therefore the flushing flow outlet, generally follows the deformation of the seal member. This means that the patient's comfortable cushion module experience is maintained without interfering with the anatomical dead-space flushing effect it provides. As described above, another advantage is that the flushing flow of breathing gas is believed to increase nasal dead-space flushing, improving the effectiveness of treatment for patients suffering from obstructive respiratory disorders.

[0527] An embodiment of a mask 210 according to the third aspect is shown in Figures 10 to 13. In those figures, features that are the same as or similar to corresponding features in the first embodiment described above are designated with like reference numerals preceded by the numeral "2."

[0528] In the mask 210, the housing 250 is the same as the housing 150 in the embodiment of the mask 110 according to the second aspect described above. It includes first and second cavities in the form of a main flow cavity 236 and a flushing flow cavity 228, respectively. Although not shown in the drawings, the mask 210 includes a mask frame having a main flow channel and a flushing flow channel, both of which deliver breathing gas to an inlet 254 in the housing 250. Specifically, the main flow channel delivers breathing gas to a lower part of the inlet 254 so that the breathing gas flows into the main flow cavity 236. The flushing flow channel delivers breathing gas to an upper part of the inlet 254 so that the breathing gas flows into the flushing flow cavity 228 (see FIG. 12 ).

[0529] Delivery of breathing gas through the inlet 254 is enabled by a cavity wall 234 that extends across the housing inlet 254 (FIGS. 12 and 13). The flushing flow cavity inlet 232 is therefore defined in part by the top of the inlet flange 256 and in part by the distal end of the cavity wall 234. In FIG. 13, it can be seen that the cavity wall 234 is sloped upward toward the nasal cradle 22 and terminates flush with the rim 238 of the seal member 212 to form the flushing flow outlet 230. Similar to the mask 110, the cavity wall 234 is shaped to form a volume that tapers inward toward the flushing flow outlet 234, thereby accelerating the breathing gas from the inlet 232 to the outlet 230.

[0530] The flushing flow outlet 230 has a lemniscate, figure-eight, or hypoped shape and is positioned immediately adjacent to the outlet leading to the nares from the main flow cavity 236. Together, the nasal outlet 226 from the main flow cavity 236 and the flushing flow outlet form a combined nasal opening for delivering a main flow of breathing gas and a flushing flow of breathing gas to the nares (FIGS. 10 and 12).

[0531] The mask 210 also differs in that it includes an exhaust flow cavity 242 formed in part by an exhaust cavity wall 248 (separating the exhaust flow cavity 242 from the flushing flow cavity 228) and in part by the outer wall of the seal member 212. The exhaust flow cavity 242 has an inlet 244 adjacent to the flushing flow outlet 230 such that the nares overlap the inlet 244, the flushing flow outlet 230, and the nasal outlet 226 when the mask 210 is worn on a patient. The exhaust flow cavity 242 also has an outlet 246 within the seal member 212, which is distal to the patient. The inlet 244 receives exhaled respiratory gas from the nares and allows the exhaled respiratory gas to travel through the exhaust flow cavity 242 and out of the mask 210 via the outlet 246, thereby exhausting the exhaled respiratory gas out of the mask. In a further aspect, the outlet 246 may be in the form of multiple vent openings. The proximity of the exhaust outlet 246 to the patient's nostrils may provide a path of less resistance for exhaled air to exit the patient's nostrils into the atmosphere, thereby increasing the efficiency of dead space flushing.

[0532] In one variation of this embodiment, the inlet 244 may form part of the flushing flow path, for example, the inlet 244 may be integrated into the rim 238 and formed in the exhaust cavity wall 248. While Figure 10 shows the mask 210 with three inlets 244, it will be understood that in other variations of this embodiment, the mask 210 may have more or fewer inlets, provided they allow exhaled breathing gas to enter the exhaust flow cavity 242. For example, one inlet 244 or two inlets 244 may be provided.

[0533] An embodiment of a mask 310 according to the fourth aspect is shown in Figures 14 to 18. In those figures, features that are the same as or similar to corresponding features in the first embodiment described above are designated with like reference numerals preceded by the numeral "3."

[0534] Similar to mask 210, mask 310 has a leading end of cavity wall 334 that defines opening 354 to divide the flow of incoming breathing gas between a first and second cavity (referred to herein as primary flow cavity 336 and flushing flow cavity 328, respectively) (FIGS. 14, 16, and 18). However, it is important to understand that, unlike the previous embodiments in which openings 54, 154, and 254 are formed in the housing, opening 354 is formed in seal member 312. Cavity wall 334 slopes upwardly from opening 354 (FIGS. 14 and 16) and terminates short of the combined nasal opening formed by flushing flow outlet 330 from primary flow cavity 336 and nasal outlet 326 (FIGS. 15 and 18). This is because flushing flow outlet 330 is formed in part by the upper rim of cavity wall 334 and in part by rim 338. However, the cavity wall 334 is connected to the wall of the cushion member by a rim 338 (FIG. 15). Connecting the cavity wall 334 by the rim 338 ensures that the cavity wall 334 moves with the rim 338 when the seal member 312 is adjusted, thereby substantially maintaining the size of the nasal outlets 326 and the flushing flow outlet 330 despite adjustments of the mask 310 that change the contours of the seal member 312 to fit the patient. This connection also has the advantage of improving the structural stability of the seal member 312, thereby reducing the risk of occlusion of the nasal outlets 326 and the flushing flow outlet 330. Despite similarities to the cavity wall 210 of the previous embodiment, the upper rim of the cavity wall 334 is recessed from the combined nasal openings and is therefore not flush with the nasal openings. However, as in the previous embodiment, the cavity wall 334, in combination with the outer wall of the seal member 312, forms a tapered volume (see FIG. 18) that accelerates the breathing gas as it flows from the opening 354 to the flushing flow outlet 330.

[0535] By recessing the upper rim of the cavity wall 334 from the combined nasal opening, contact with the patient's septum can be avoided, thus avoiding irritation and improving patient comfort. Furthermore, the spacing between the upper rim and the nostrils creates a vestibular chamber, which allows for smoother gas flow because there is space for gas to enter as it exits the nostril. In contrast, if the rim 338 of the combined nasal opening contacted the nostril, exhaled breathing gas from the nostril would be divided by the rim 338 between the flushing flow cavity 328 and the main flow cavity 336. For example, during exhalation through the nose, the addition of a vestibular chamber formed by the recessed upper rim of the cavity wall 334 means that exhaled breathing gas would enter the vestibular chamber and then flow into the main flow cavity 336 without some breathing gas being divided and routed to the flushing flow cavity 328.

[0536] Similar to the other masks described above, the mask 310 has a primary flow cavity 336 that operates to deliver breathing gas to the patient through an oral opening 324 and nasal outlets 326 (as shown in FIG. 18 by the arrows indicating the flow of breathing gas to the oral opening 324 and nasal outlets 326). The nasal outlets 326 are formed proximal to the seal member 312 between a rim 338 and the cavity wall 334.

[0537] In contrast to the masks described above, the mask frame 370, while having the same buccal wings 374 and connector bar 376, only includes a primary flow channel 382 for delivering breathing gas from the gas source to the opening 354. In view of the single flow channel of the mask frame 370, a flushing flow channel is not incorporated into the mask frame 370, as the flow of breathing gas into the flushing flow cavity 328 is delivered by the primary flow channel 382. The single flow channel is beneficial by simplifying the connections between the mask 310 and mask frame 370 and the cushion module 320, thus reducing any risks associated with, for example, correctly setting up the mask 310.

[0538] It will be appreciated that with a single flow channel delivering breathing gas to the primary flow channel 382 and the flushing flow channel 384, the resistance to flow in each of the flushing flow cavity 328 and the primary flow cavity 336 is crucial to ensuring adequate delivery of breathing gas at the pressure and velocity to achieve the desired therapy. In other words, the ratio of the resistance to flow through the flushing flow cavity 328 and the primary flow cavity 336 determines the division of the breathing gas flow between the two cavities. As a result of this, flow can be set by designing the cavities with the required relative resistance to flow in each of the cavities. With respect to the flushing flow outlet 330 and the nasal outlet 326, the flow resistance can be adjusted by changing the cross-sectional area of ​​the flushing flow outlet 330 and the nasal outlet 326. Low flow resistance is advantageous for a cough. This is also possible due to the low angle flow direction changes (typically in the range of 0-20°) of the breathing gas through the cushion module 320.

[0539] A significant difference between the mask 310 and the masks of the previous embodiments is the housing 350, which includes lateral members having spaced-apart lateral sections defining a gap that flares outward on at least one side, as shown in FIGS. 19A and 19B. As shown in FIGS. 19A and 19B, the housing 350 has a generally U-shaped configuration, but may alternatively have an inverted U-, V-, or H-shaped configuration. As with the previous embodiments, the periphery of the housing 350 includes a peripheral feature that allows for the securing of a resilient seal member to form a cushion module incorporating the housing. The peripheral feature includes a series of holes sized to allow the securing of the resilient seal member 312 by overmolding. In this embodiment, the peripheral feature includes a series of outwardly extending tab members 360 that support, at their outer ends, a continuous bead 362 that forms the periphery of the housing 350. Tabs 360 and beads 362 form a series of window-shaped holes over which seal member 312 is overmolded to form a permanent connection, or interlock, between housing 350 and seal member 312 .

[0540] The U-shape of the housing 350 allows the opening 354 to be formed much larger than in other embodiments (FIGS. 14 and 16). This means that the transition of breathing gas from the mask frame 370 to the flushing flow cavity 328 and the main flow cavity 336 is smoother, potentially reducing undesirable amounts of turbulence, while also providing lower flow resistance through both. Low flow resistance is important for achieving the correct ratio of breathing gas flow between the flushing flow cavity 328 and the main flow cavity 336. The larger opening 354 also allows for a larger mold tool core to be removed from the opening 354 when overmolding the seal member 312 onto the housing 350, which is important, for example, when designing complex multi-cavity silicone parts. This allows for greater flexibility in the shape of the cavities that can be formed in the cushion module to control the flow of breathing gas.

[0541] An embodiment of a mask 410 according to a variant of the first aspect is shown in Figures 20 to 24. In those figures, features that are identical or similar to corresponding features in the first embodiment described above are designated with like reference numerals preceded by the numeral "4."

[0542] A cross section of the mask 410 is shown in FIG. 20A, and front and side views of the mask 410 are shown in FIGS. 1 and 23, respectively. The housing 450 of the mask 410 is the same as the housing 350 of the mask 310, except that the seal member 412 is formed as a conduit, in this embodiment in the form of a tube, that defines a flushing flow cavity 428 and is surrounded by a main flow cavity 436. The main flow cavity 536 and the flushing flow cavity 428 define first and second cavities, respectively. A flushing flow outlet 430 at the proximal end of the tube is not connected to the outer wall of the cushion module 420 within the nasal cradle 422. In other words, the flushing flow outlet 430 is independently movable relative to the seal member 412 and relative to the nasal outlet 426. This may provide a more comfortable mask, or in other words, a mask that can accommodate a wider range of face shapes, due to the decoupling of movement between the nasal openings 426 and the flushing flow outlet 430. This decoupling is more clearly shown in Figures 20B and 21, where the flushing flow outlet 430 is shown as being recessed from and not connected to the rim 438 of the seal member 412.

[0543] The flushing flow cavity 428 is integrally formed with the seal member 412 and is connected at its distal end to the seal member 412, where the seal member 412 is attached to the housing 50. The molded product is then overmolded (Figures 20A and 21).

[0544] The mask frame 470 includes two primary flow channels 482 (when viewing FIG. 21 in conjunction with FIG. 1, which is a front plan view of the mask 410 shown in FIG. 21, one primary flow channel is associated with each inlet 480) and a single flushing flow channel 484. Both primary flow channels 482 deliver breathing gas to the primary flow cavity 436, and the single flushing flow channel 484 delivers breathing gas to the flushing flow cavity 428. It should, of course, be understood that a mask frame may have only a single primary flow channel. While FIG. 21 shows the flow of breathing gas through the mask frame 470 and cushion module 420, this illustration is schematic and does not show one of the two primary flow channels 482. Alternatively, one of the primary flow channels 482 may be used to sample mask pressure and the other to deliver pressurized gas. Furthermore, in additional embodiments, one of the primary flow channels 482 may be used to deliver supplemental oxygen or a different gas mixture than that delivered through the remaining primary flow channel 482. While Figure 21 shows a single arrow indicating that breathing gas flows through primary flow channel 482 as it enters primary flow cavity 36, it will be understood that the breathing gas may then be delivered to the patient through mouth opening 424, nasal outlet 426, or both.

[0545] It will further be appreciated that mask 410 operates in the same manner as mask 10 to treat obstructive respiratory disorders by flushing anatomical dead spaces and by applying elevated air pressure above ambient air pressure to the patient's respiratory system.

[0546] Separating the flushing flow outlet 430 from the nasal cradle 422 avoids creating a connection between two areas where the material is thicker than other areas. Thicker areas are less flexible and therefore less adaptable to the shape of the face. That is, these stiffer areas may cause pressure sores or patient pain when wearing the mask 410 for extended periods of time. Separating the flushing flow outlet 430 from the nasal cradle 422 may improve patient comfort, but the flushing flow outlet 430 does not follow the movements of the nasal outlet 426 as well. The variations shown in FIGS. 22 and 24 provide an option that allows for compliance (for the purpose of providing effective therapy) and allows for comfort that reduces the likelihood of patient pain and pressure sores.

[0547] FIG. 22 shows four options for the support link between the flushing flow cavity 428 and the cushion module 420: FIG. 22A shows a web 402 above the flushing flow cavity 428 and extending distally from the rim 438 and flushing flow outlet 430 . FIG. 22B shows a partition wall 404 above the flushing flow cavity 428 , extending distally from the rim 438 and the flushing flow outlet 30 , and running the full length of the flushing flow cavity 428 . FIG. 22C shows a single rib or tie 406 connecting the flushing flow cavity 428 to the nasal cradle 422, the rib or tie 406 being located above the flushing flow cavity 428 and spaced distally from the rim 438 and the flushing flow outlet 430. FIG. 22D shows two separate tethers 408 extending in opposite directions from the flushing flow outlet 430 towards and connecting with the rim 438 .

[0548] Figure 24 shows four different tether 408 configurations that can be used in place of or in combination with the support links shown in Figures 22A-22D. The tethers 408 can provide lateral, longitudinal, or both lateral and longitudinal support to the flushing flow cavity 428. In particular, - Figure 24A shows a tether 408a that extends from the reinforced shoulder 96 of the cushion module 420 to the upper corner of the flushing flow cavity 428. The tether 408a tapers outward from its midpoint to its end. - Figure 24B shows tethers 408b extending from the side rib portions 98 of the cushion module 420 to the upper corners of the flushing flow cavity 428. The tethers 408b taper outward from their midpoints to their ends. - Figure 24C shows a tether 408c that extends from adjacent the bottom of the nose cradle 422 to the top corner of the flushing flow cavity 428. The tether 408c has a constant cross section throughout its length. - Figure 24D shows a short tether 408d that extends from the upper midpoint of the flushing flow cavity 428 to the bottom of the nasal passage 422. The tether 408d tapers outward towards its end.

[0549] From the above options for the configuration of the support links and tethers 408, it will be understood that the mask 410 may include one or more web members (e.g., support links, tethers, or both) connecting the flushing flow cavity 428 to the seal member 412 such that the flushing flow outlets 430 conform to the nasal outlets 426 when the cushion module is deformed, for example, by donning the mask 410 on a patient. In other words, the support links and tethers allow the flushing flow cavity 428 to conform to the nasal outlets 426 for different face shapes. However, it is important to understand that the location and shape of the web members (e.g., support links, tethers, or both) are selected to substantially preserve the flexibility of the cushion module without the web members and to avoid areas of undesirable increased thickness that may lead to patient discomfort.

[0550] Compliance is achieved by connecting one or more web members (such as support links, tethers, or both) to the cushion module 420 in a position such that when the cushion module is deformed by the patient's nose during fitting or adjustment, the one or more web members apply a force to the flushing flow cavity 428.

[0551] 24A and 24B illustrate one option for enabling compliance without increasing the stiffness of the area of ​​the seal member 412 that contacts the patient. These figures show tethers 408a and 408b connecting to reinforced shoulder 496 and side rib 498 portions of the cushion module. The choice of these tether points arises because the cushion module 420 includes flexible regions that conform to the shape of the patient's face and relatively inflexible structural regions that support the flexible regions. The structural regions, i.e., shoulder 496 and side rib 498, in these variations comprise portions of the cushion module 420 that are attached to the housing 450 via overmolding; i.e., the portions of the cushion module 420 into which the tab members 460 and beads 462 are embedded. However, it will be understood that other structural regions can be used as anchor points for the tethers and support links.

[0552] In a variation of this embodiment, one or more web members (such as support links, tethers, or both) may be coupled to flexible regions of the cushion module 420 that conform to the shape of the patient's face.

[0553] An embodiment of a mask 510 according to a further variant of the first aspect is shown in Figures 24 to 29.

[0554] The seal member 512 is made of a soft and elastic material, and when attached to the patient, 19A and 19B , the cushion module 520 includes a mouth opening 524 that circumscribes the patient's mouth and also includes nasal openings 526 located in the valleys of the nasal cradle 522. The nasal openings 526 are specifically positioned to align with the patient's nares when the mask 510 is fitted to the patient. Openings 554 for delivering breathing gas into and through the cushion module 520 are formed in the cushion module 520 opposite the mouth opening 524. The seal member 512 is permanently secured to a housing 550 that is the same configuration as the housing 450 described above and shown in FIGS. 19A and 19B . The cushion module 520 defines a primary flow cavity 536 (i.e., a first cavity) through which breathing gas is delivered to the mouth opening 524 and nasal openings 526.

[0555] The mask 510 further includes a mask frame 570 having side wings 574 and a connector bar 576, and a single primary flow channel inlet 580 for routing breathing gas to a downstream primary flow channel outlet 588, which delivers breathing gas into the primary flow cavity 536 via the openings 554. The mask 510 also includes a flushing flow channel 584 downstream of the primary flow channel inlet 580 for routing breathing gas via the flushing flow channel inlet 578 to the flushing flow channel 584 and subsequently to the flushing flow cavity 528 (i.e., the second cavity), as shown in FIGS. 26 and 27 . The flushing flow channel 584 is formed as a tube extending proximally away from the main body 572 of the mask frame 570. When the mask frame 570 is attached to the cushion module 520, the flushing flow channel 584 protrudes inside the cushion module 520 in a direction toward the nasal openings 526.

[0556] The flushing flow cavity 528 (see FIGS. 26 and 27 ) is formed separately from the mask frame 570 and cushion module 520 and is connected to the mask frame 570 at a flushing flow channel outlet 586. The flushing flow cavity 528 is formed of a soft, conformable, and resilient material so that the relatively thin-walled outlet 530 can easily deform to accommodate different facial shapes. In contrast, the inlet 532 has a thicker wall and is therefore less flexible, forming a rigid connection with the mask frame 570 so that deformation of the outlet 530 does not disconnect the flushing flow cavity 528 from the flushing flow channel 584. While the flushing flow channel 584 has a generally uniform cross-section overall, the flushing flow cavity 528 defines a passageway that tapers inwardly from its inlet 532 to its outlet 530 to accelerate breathing gas and direct it into the patient's nares.

[0557] The flushing flow cavity 528 and the flushing flow channel 584 have cooperating features, such as snap-fit ​​features (FIGS. 27 and 28), that allow the flushing flow cavity 528 to fit into the flushing flow channel 584 so that the outlet 530 is flush with or slightly recessed from the nasal openings 526 (FIG. 27). According to this embodiment, the cooperating features on the flushing flow channel 584 include a flange 540 that projects radially outward from and at least partially around the outlet 586 of the flushing flow channel 584. The inner wall of the flushing flow cavity 528 has a flange-receiving groove 542 adjacent the inlet 532. The groove 542 has a profile that complements the profile of the flange 540, so that they fit together to securely couple the flushing flow cavity 530 to the flushing flow channel 584.

[0558] In one variation, the cooperable features may include a keyed fitting of the flushing flow channel 584 and an inlet end to the flushing flow cavity 528 that is closely sized relative to the keyed fitting such that the inlet end must resiliently deform to receive the keyed fitting. The inlet end of 28 may be overmolded around a rigid connecting member, such as a ring, that snaps into a cooperating feature on flushing flow channel 584. A range of alternative cooperating features can be used that provide a substantially airtight connection between flushing flow cavity 528 and flushing flow channel 584 upon increase in gas pressure.

[0559] While the shape of groove 542 and flange 540 may take any suitable form that provides a secure connection, in this embodiment groove 542 is formed to limit the extent to which flushing flow cavity 528 can fit within flushing flow channel 584, with limit wall 544 abutting end wall 546 of flushing flow channel 584. Limit wall 544 thereby ensures proper positioning of flushing flow cavity 528 to direct breathing gases to the patient's nares when the interface is worn on the patient.

[0560] The cooperable features further include a recess 548 adjacent and distal to the end wall 546. The flange-receiving groove 542 defines a radially inward lip 502 that latches into the recess 548 when the flange 540 seats in the groove 542. This arrangement ensures proper placement of the flushing flow cavity 528 to direct breathing gases into the patient's nares when the mask 510 is worn on a patient.

[0561] To help reduce resistance to the flow of breathing gas, the inner walls of flushing flow channel 584 are flush with the inner walls of flushing flow cavity 528 at the point where flushing flow cavity 528 connects to flushing flow channel 584 .

[0562] In a variation of this embodiment, the profile of the flushing flow cavity 528 includes one or more preferential deformation zones in the form of bands 508 of reduced wall thickness (as shown in FIGS. 29A-29D ) or, in alternative embodiments, regions of reduced thickness away from the flushing flow outlet 530 to allow the flushing flow cavity 528 to follow the movement of the nasal opening 526 while substantially maintaining the shape of the flushing flow outlet 530. Locating the bands 508 closer to the inlet end of the flushing flow cavity 528 means that deformation occurs in areas of the flushing flow cavity 528 that have a larger cross-sectional area compared to areas downstream where the taper of the flushing flow cavity 528 means that the cross-sectional area is smaller. Thus, the bands 508 reduce the likelihood of the flushing flow cavity 528 becoming blocked as it deforms to follow the nasal opening 526.

[0563] The variation shown in Figures 29A and 29B shows a flushing flow cavity 528 with a single band 508. The band 508 includes a region where the thickness of the cavity wall 534 is reduced compared to the thickness of the wall 534 in an adjacent region. Another variation shown in Figures 29C and 29D includes two bands 508. The band 508 has a curved profile, but it will be understood that the band 508 can have other profiles that allow for preferential deformation at the band's location. For example, an alternative profile is a square profile. The location of the band 508 on the outside of the flushing flow cavity 528 ensures that the interior wall 506 remains smooth, thus providing a low flow resistance flow path through the flushing flow cavity.

[0564] An embodiment of a mask 610 according to the seventh and eighth aspects is shown in Figures 30-42.

[0565] Mask 610 includes a seal member 612 that is permanently secured to a housing 650 (same configuration as the housing shown in Figures 19A and 19B) by overmolding to form a cushion module 620. The seal member 612 is made of a soft material such as silicone. The mask 610 includes a mouth opening 624 formed of a resilient material that circumscribes the patient's mouth when worn on a patient, and includes combined nasal openings 626, 630 located in the valley of the nasal cradle 622. The combined nasal opening includes an adjacently disposed main flow outlet 626 and a flushing flow outlet 630. Cavity walls 634 are formed within the interior of the seal member 620 to define first and second cavities, i.e., a main flow cavity 636 and a flushing flow cavity 628, respectively. The flushing flow cavity 628 is formed in an upper portion of the seal member 620, and the main flow cavity 636 is formed within the remainder of the seal member 620 in combination with the housing 650. The nasal outlets 626 are positioned to fit over the patient's nares, particularly when the mask 610 is worn on a patient. Additionally, the cavity walls 634 are positioned to allow breathing gas from the flushing flow cavity 628 to enter the nares and to allow exhaled gas to exit the nares into the primary flow cavity 636. Additionally, the cavity walls 634 are positioned to allow excess breathing gas from the flushing flow cavity 628 to pass between the cavity walls and the patient's face into the primary flow cavity 636 and be exhausted to the atmosphere through an exhaust vent in the primary flow cavity 636.

[0566] An opening 654 for delivering breathing gas into or through the cushion module 620 is formed in the seal member 612 opposite the mouth opening 624. Together, the seal member 612 and the housing 650 define a primary flow cavity 636 through which breathing gas is delivered to the mouth opening 624 and the nasal outlets 626.

[0567] The housing 650 includes two pressure ports (P) that allow measurement of gas pressure within the mask 610 when the mask 610 is worn on a patient. The housing further includes a bias vent 652 for directing exhaled breathing gas from within the mask 610 to the exterior of the mask 610. The bias vent 652 is of the same form as the bias vent 52 disclosed above.

[0568] The mask 610 further includes a mask frame 670 (see FIGS. 36-41 ) having side wings 674 and a connector bar 676, and a single primary flow channel inlet 680 for routing breathing gas to a downstream primary flow channel outlet 688 that delivers breathing gas through opening 654 into the primary flow cavity 636. The mask 610 also has a flushing flow channel 684 downstream of the primary flow channel inlet 680 for routing breathing gas via the flushing flow channel inlet 678 to the flushing flow channel 684 and subsequently to the flushing flow cavity 628 (as shown in FIG. 37 ).

[0569] As shown in FIGS. 30-35 , the cavity wall 634 includes one or more preferential deformation regions that accommodate deformation of the cavity wall 634 without obstructing the flushing flow cavity 628. Specifically, the cavity wall 634 includes a series of panels that enable preferential deformation of the cavity wall 634 in a manner that reduces the likelihood of obstruction of the flushing flow cavity 628. Specifically, the cavity wall 634 includes a main panel 700, a deflector panel 706, a transition panel 702, and a shear panel 704 (see FIGS. 35A-35C ). The main panel 700 extends to and partitions the opening 654 to form the flushing flow cavity inlet 632 and the primary flow cavity inlet 636. The main panel 700 is configured to interact with the mask frame 670 to substantially isolate the primary flow cavity 636 from the flushing flow cavity 684 at the location where the mask frame and cushion module are attached. The cavity wall 634 curves upward from the inlet 632 toward the side of the seal member 620 (as shown in Figures 30 and 32-34).

[0570] The cavity wall 634 is recessed from the combined nasal openings 626, 630 and is secured by a tether 710 that is recessed from the rim 638 of the nasal openings 626, 630 to avoid contact with the patient. , and coupled to the seal member 612 adjacent the rim 638. The deflector panel 706 of the cavity wall 634 curves proximally away from the opening 654 (as shown in FIGS. 35A, 35B, and 35C ) and terminates at its upper edge at a rim 708 that is recessed from the rim 638 of the nasal openings 626, 630 to form an antechamber below the nares when the mask 610 is worn on a patient, as described above with reference to the mask 410 ( FIGS. 32 and 37 ). The deflector panel 706 is connected directly around the nasal openings 626, 630 at its lateral sides and is connected to proximal and distal points around the nasal openings 626, 630 by tethers 710. In another aspect, the deflector panel 706 may be connected to the seal member 612 at its lateral sides at a location spaced from the nasal openings 626, 630. The tether 710 curves downward from around the nasal openings 626, 630 to join the rim 708 of the deflector panel 706. Thus, the tether 710 does not come into contact with the patient when the mask 610 is worn.

[0571] The shear panel 704 in the cavity wall 634 provides at least one of the preferential deformation regions. The shear panel 704 has a generally U-shaped configuration ( FIG. 35 ) because it follows the perimeter of the deflector panel 706 and thus extends around the perimeter of the deflector panel 706 from one side of the nose cradle 622 to the other. The shear panel has a curved profile ( FIGS. 32 , 34 , and 37 ) from the edge of the deflector panel 706 to the proximal edge of the transition panel 702. The distal edge of the transition panel 702 joins with the main panel 700.

[0572] It will be appreciated that the deformation region decouples one portion of the cavity wall from the other portion of the cavity wall so that a force applied to one portion is not transmitted to the other portion. Furthermore, the two portions of the cavity wall (i.e., the upstream main panel 700 and the downstream deflector panel 706) are each shaped to resist deformation. The decoupling occurs because, as seen in FIGS. 32-35 and 37, the deflector panel 706 is tilted relative to the main panel; therefore, reciprocating motion of the deflector panel 706 would be resisted by the main panel 700 if they were directly connected to each other. However, because the shear panel 704 forms a flexible connection between the deflector panel 706 and the main panel 700, deflection of the deflector panel 706 is absorbed by the shear panel 704 (i.e., not transmitted to the main panel 700) to a limited extent. The shear panel 704 has a reduced wall thickness compared to the main panel 700 and the deflector panel 706. This means that the shear panel 704 is more flexible than the main panel 700 and the deflector panel 706, and therefore the shear panel 704 deforms preferentially before the deflector panel 706 or the main panel 704 deform. The shape of the shear panel 704 is selected such that when either the main panel 700, the deflector panel 706, or both, translate relative to each other, the shear panel 704 rolls thereover. As a result, when the seal member 612 is subjected to a deformation force, the main panel 700 and the deflector panel 706 transfer the deformation force to the deformation region (e.g., the shear panel 704), thereby having the effect of substantially maintaining the shape of the flushing flow cavity 628 such that deformation of the cavity wall 634 is substantially limited to the deformation region.

[0573] Because the deformation is concentrated in the shear panel 704, the deflector panel 706 and the main panel 700 generally remain in their original shape and / or position relative to one another, thus leaving the flushing flow cavity 628 open for the free flow of breathing gas. The likelihood of the deflector panel 706 and the main panel 700 buckling or folding in a manner that blocks the flushing flow cavity 628 is reduced, thereby reducing partial or complete blockage of the flushing flow cavity 628. Furthermore, because the preferential deformation is concentrated in the shear panel 704, the resistance to flow through the flushing flow cavity is unlikely to increase significantly. This means that the required flow ratio of breathing gas through the main flow cavity 636 and the flushing flow cavity 628 is generally maintained, thereby providing effective therapy to the patient. The preferential deformation of the shear panel 704 and the slight deformation of the deflector panel 706 are unlikely to increase significantly. The deviations that will be generally accommodated by the small variations are those associated with different facial shapes and the adjustment of the mask 610 on the patient's face.

[0574] As previously discussed, the ratio of the cross-sectional areas of the flushing flow outlet 630 and the nasal outlet 626 provides control of the flow of respiratory gas to provide effective therapy, including flushing of anatomical dead spaces. In this embodiment, the cavity wall 634 is connected to the rim 638 of the nasal openings 626, 630 to define the cross-sectional areas of the flushing flow outlet 630 and the nasal outlet 626 and resist changes in the cross-sectional areas of the flushing flow outlet 630 and the nasal outlet 626 as the seal member 620 deforms. Maintaining the ratio relies on maintaining the deflector panel 706 in a recessed position relative to the nasal openings 626, 630. This is facilitated in this embodiment by a reinforcing bead 712 ( FIG. 34 ) that extends around the rim 638 of the nasal openings 626, 630. The bead 712 has a wall thickness greater than that of the surrounding seal member 620 such that the bead 712 is less flexible (i.e., less susceptible to deformation) than the surrounding seal member, thus resisting blockage or deformation of the nasal openings. The same applies to maintaining the shape of the rim 638 and the spacing of the deflector panel 706 from the nasal openings 626, 630 when the seal member 612 is subjected to increased gas pressure during treatment. Therefore, deflection of the nasal cradle 622 is concentrated by the bead 712 and tether 710 toward the deflector panel 706. However, the curved shape of the deflector panel 706 makes it relatively stiff compared to the shear panel 704, and as a result, the deflection of the deflector panel 706 is transferred to the deflecting shear panel 704. That is, even if the seal member 620 deforms to a certain extent, the deflector panel 706 remains in position relative to the nasal openings, such that a pre-defined chamber remains between the end of the deflector panel 706 and the nasal openings. Therefore, by preferentially deforming the shear panel 704 to a certain extent, buckling or deformation of the deflector panel 706 and the main panel 700 can be avoided. It will be appreciated that beyond the point where deformation of the deflector panel 706 and main panel 700 occurs, their configuration means that they deform in a manner that limits the extent to which the flushing flow cavity 728 is obstructed.Thus, the mask 610 accommodates a wider range of facial shapes, thus reducing the likelihood that the flushing flow cavity 628 and nasal openings 626, 630 will become blocked.

[0575] During use, when the mask 610 is worn, forces are applied to the face-contacting surface of the seal member 612 due to different face shapes, headgear preferences, and pressure settings. These forces and the locations at which they are applied vary. However, the configuration described above concentrates the forces and deflections in preferential deformation regions (i.e., shear panels 704 in this embodiment), resulting in a predictable collapse and rebound behavior. The predictable buckling pattern achieved through preferred deformation regions allows the mask 610 to be designed such that when forces are applied to the seal, the resulting deformation and compression of the elastomeric material forming the seal member 612 occurs in a manner that ensures that openings and cavities remain unobstructed. Without preferential deformation regions, the collapse of the deflector wall 706 would be unpredictable, potentially resulting in inconsistent flow through the openings and cavities of the mask 610. This would lead to inconsistencies in achieved therapy, comfort, wearing procedure, and overall performance between uses on the same patient and between different patients.

[0576] In variations on this embodiment, the seal member 612 may have multiple regions of preferential deformation. For example, additional regions of preferential deformation may be incorporated into the cavity wall 634 or at other locations on the seal member 612 that allow the flushing flow cavity 628 and / or nasal openings 626, 630 to substantially retain their shape, substantially maintain the ratio of the cross-sectional areas of the flushing flow outlet 630 and the nasal outlet 630, or both.

[0577] 36-41, the mask 610 includes a mask frame 670 of the same general configuration as described in the previous embodiments. Specifically, the mask frame 670 includes a body 672 having side wings 674, each of which includes upper and lower connector bars 676 for fastening the mask frame 670 to headgear that holds the mask 610 on the patient's face.

[0578] FIGS. 38-40 illustrate the structure and flow paths of the mask frame 670. In particular, the mask frame 670 has a single primary flow channel inlet 680 that leads to a primary flow channel 682. Downstream of the primary flow channel inlet 680 is a divider 734 that divides the flow of breathing gas between the primary flow channel 682 and the flushing flow channel 684. The cross-sectional areas of the primary flow channel 682 and the flushing flow channel 684 are selected to provide flushing flow for flushing anatomical dead spaces and to provide the necessary volumetric flow rates of breathing gas for breathing. FIGS. 37 and 38 show that the area of ​​the inlet to the flushing flow channel 684 is larger than the combined area of ​​the inlets to the primary flow channel 682, and thus the flow through the flushing flow channel 684 has a lower resistance to flow (at least at the point of inlet) than the resistance to flow through the primary flow channel 682. However, this may be reversed or adjusted in other embodiments to correct for flow biases through the mask frame 670 depending on the treatment.

[0579] The upper portion of the flushing flow channel 684 includes a partition wall 750 that leads to an outlet 752. As shown in FIG. 39 , when the mask frame 670 is attached to the cushion module 620 (including the seal member 612 and the housing 650), the partition wall 750 presses firmly against the upper surface of the main panel 700, forming a generally airtight seal. Thus, breathing gas flowing through the flushing flow channel 684 passes through the partition wall 750 and enters the flushing flow cavity 628, as shown in FIG. 37 . The main flow channel 682 opens at an outlet 754 between the underside of the partition wall 750 and a U-shaped lip 730 extending proximally from the mask frame 670. Breathing gas exiting the outlet 754 travels to the main flow cavity 636, from which the breathing gas is delivered to the patient via the mouth openings 624, the nasal openings 626, or both.

[0580] To connect the cushion module 620 to the mask frame 670, the mask frame 670 includes a seat 728 formed as a groove by a proximally extending ledge 724 and a retaining wall 726 extending generally perpendicular to the ledge 724 and generally parallel to the body 672. Additionally, the mask frame 670 includes a bead 732 at the outermost edge of the lip 730 (see FIG. 38). As shown in FIG. 37, the upper rim 720 of the opening 654 seats on the seat 728, and the lower rim 724 of the opening 654 is threaded over the bead 732 and seats tightly against the outside of the lip 730 to form a generally airtight seal between the opening 654 and the mask frame 670. Additionally, the mask frame 770 is cooperable with the cavity wall 634 to separate the main flow cavity 636 from the flushing flow cavity 628.

[0581] Different facial shapes and headgear conditions can, during use, cause at least a portion of the flow path to either the mouth opening 624, nasal outlet 626, or flushing flow outlet 630 to become blocked. When this occurs, the flow rate required to achieve the required pressure delivered to the patient may not be able to be delivered through the restriction in the unblocked flow path (usually the point where the flow branches off).

[0582] To address this, the gate 734 includes a pressure relief valve in the form of a flap valve, mushroom valve, or flexible poppet valve 760 that allows breathing gas from the flushing flow channel 684 to travel through the valve opening 736 to the main flow channel 682. 39 and 40. The poppet valve 760 includes a stem 754 that seats on the valve seat 738 and also includes a cap 752 from whose center point the stem 754 projects. The cap 752 has a generally dome-like shape with an outer rim that extends beyond the valve opening 736 and contacts the partition 734 to form a seal separating the breathing gas in the flushing flow cavity 684 from the breathing gas in the main flow channel 682 when the poppet valve 760 seats on the valve seat 738 (as shown in FIG. 41A).

[0583] At least the cap 752 is formed of a resilient elastomeric material, and the resilience of the material is selected to allow breathing gas in the flushing flow channel 684 to flow into the main flow channel 682 when the breathing gas in the flushing flow channel 684 exceeds a threshold gas pressure. Once the threshold pressure is exceeded, the gas pressure causes the cap 752 to deflect away from the partition (as shown in FIG. 41B ), thereby breaking the seal and allowing breathing gas to flow from the flushing flow channel 684 to the main flow channel 682. When the gas pressure in the flushing flow channel 684 drops below the threshold pressure, the poppet valve 760 closes. If the flow path through the main flow cavity becomes blocked, breathing gas continues to flow through the flushing flow channel 684, thereby delivering breathing gas to the patient despite the blocked flow path. This flow combination allows the appropriate therapeutic pressure to be delivered through only one of the flow path openings (i.e., one of the mouth opening 624, nasal outlet 626, or flushing flow outlet 630). In some embodiments, the threshold gas pressure may be defined by the pressure difference between the flushing flow channel 684 and the main flow channel 682 .

[0584] It will be appreciated that because the sizes of the flushing flow channel 684 and the main flow channel 682 differ in alternative embodiments to provide alternative therapies, the valve 740 may be configured to allow the flow of breathing gas from the main flow channel 682 to the flushing flow channel 684, or may be configured bidirectionally to allow gas to flow in both directions between the main flow channel 682 and the flushing flow channel 684.

[0585] While not wishing to be bound by any particular theory, applicants believe that the interface 610 operates during the inhalation and exhalation phases of the breathing cycle in the manner shown in Figures 42A and 42B. Specifically, during the inhalation phase (Figure 42A), breathing gas is substantially provided by the flushing flow supplied through the flushing flow cavity 628, but if peak inhalation demand exceeds the flow available through the flushing flow cavity 628, some flow may be entrained from the primary flow cavity 636 via the nasal outlet 626. During the exhalation phase (Figure 42B), it is expected that flow exiting the nasal cavity enters the primary flow cavity 636 of the cushion module 620 (due to the relatively low gas pressure in the primary flow cavity 636 compared to the gas pressure in the flushing flow cavity 628) and may thereby be vented to atmosphere via the bias flow vent 652. To achieve this, a gap must be formed between the nostril and the cavity wall 634 that separates the main flow cavity 636 and the flushing flow cavity. It is believed that the recessed location of the rim 708 relative to the nasal outlet 626, along with the deformation area formed in the cavity wall 634, allows this flow arrangement to occur.

[0586] The problem of obstruction or restriction of gas flow through the seal member to the nostril or oral opening can occur in all of the described embodiments, and for this reason a pressure relief valve may be employed in any of the patient interfaces described above.

[0587] An embodiment of a mask 810 according to the ninth aspect disclosed above is shown in Figures 43-49.

[0588] Mask 810 includes a seal member 612 and a housing 650 in the same configuration as cushion module 620 described above with respect to mask 610, except that in this embodiment, housing 650 does not include a bias vent hole for venting exhaled respiratory gas to the exterior of mask 810. The same reference numerals used in FIGS. 30-42 to describe mask 610 are used in FIGS. 43-49 to indicate the same features in mask 810. Thus, mask 810 includes the same preferentially deformable cavity wall 634 as disclosed with respect to mask 610, as shown in the figures. Accordingly, the following description should be read with the assumption that the same cavity wall 634 is present in mask 810.

[0589] The mask 810 further includes a mask frame 870 that differs from the mask frame 670 of the mask 610. Specifically, the mask frame 870 includes a main body 872 having side wings 874 and a connector bar 876 for attaching the mask frame 870 to headgear, while the mask frame 870 has a single main flow channel inlet 880 that delivers breathing gas into the main flow cavity 636 via the openings 654 and also has a single outlet 888. The breathing gas can then be inhaled by the patient via the mouth openings 624, via the nasal outlets 626, or both. The mask frame 870 includes a main flow channel 882 with the inlet 880 positioned relative to its outlet 888 such that the breathing gas undergoes a small (0-5°) change in direction along the length of the channel 882. In this embodiment, the inlet 880 is opposite the outlet 888. This arrangement provides the main flow channel 882 with low resistance to gas flow. The single inlet 880 and single outlet 888 are believed to result in less restrictive flow of breathing gas through the mask 810 by avoiding multiple counter-moving gas streams that can interfere with each other.

[0590] To connect the cushion module 620 to the mask frame 870, the mask frame 870 includes a seat 928 formed as a groove by a proximally extending ledge 924, and a retention wall 926 extending generally perpendicular to the ledge 924 and generally parallel to the body 672. Additionally, the mask frame 870 includes a bead 932 at the outermost edge of a U-shaped lip 930. As shown in FIG. 44 , the upper rim 720 of the opening 654 seats in the seat 928, and the lower rim 724 of the opening 654 is threaded over the bead 932 and seats tightly against the outside of the lip 930, forming a generally airtight seal between the opening 654 and the mask frame 870.

[0591] Mask 870 further differs from mask frame 670 in that there is no inlet for fresh breathing gas from the gas source to the flushing flow cavity. Instead, mask frame 870 includes bias vent holes 652 in body 672 below ledge 924. The cavity is therefore an exhaust cavity 940, as shown in FIGS. 45-47, with exhaled breathing gas (from the mouth, nostrils, or both) flowing through exhaust cavity 940 and exhaled breathing gas flushed from the dead space in the patient's nasal passages flowing through exhaust cavity 940 (FIG. 46) and exiting through bias vent holes 652. Mask frame 870, in cooperation with cavity wall 634, separates primary flow cavity 636 (i.e., the first cavity) from exhaust cavity 628 (i.e., the second cavity). More specifically, the divider wall 950 is securely pressed against the top surface of the main panel 700 of the cavity wall 634 to form a generally airtight seal so that exhaled breathing gas from the nostrils does not flow into the main flow cavity 636 but instead exits the mask 810 through the bias vent holes 652. Additionally, exhaled gas from the mouth is routed along with the breathing gas to the exhaust cavity 940, as shown in FIG. 47, from where the exhaled gas exits the mask 810.

[0592] The seal member 612 and the housing 650 are the same as those in the previous embodiments, but the mask frame 870 has a different effect. Specifically, the partition wall 950 provides more efficient exhaust. The location of the exhaust vent in the exhaust cavity 940 with a single flow path into the main flow cavity 636 leading to the mask 810 and directing the flushing flow either into the user's anatomical dead space (for mouth breathing) or into the nostrils (for nose breathing) without actually having a dedicated flushing flow channel. In order for breathing and exhaled gases to exit the mask 810, one of the following is required: a) flushing exhaled air from the user's oral and nasal cavities during exhalation by flowing through the mouth and out the nose; or b) Flow through the divider wall, which creates a flushing flow towards the nares due to the restricted flow path in that area of ​​the cushion module 620 as the divider wall is closer to the patient. Thus, in either of the above situations, the patient's anatomical dead space is at least partially flushed.

[0593] The above-described arrangement for connecting the cushion module 620 to the mask frame 870 is one example of a connection. Other arrangements may be used, provided that the connection is capable of withstanding elevated gas pressures. For example, the above-described connection allows the cushion module 620 to be separated from the mask frame 870 for cleaning. However, the connection may be a permanent connection. In a further alternative, the mask frame 870 and the housing 650 may be integrally formed, allowing the cushion module to be later overmolded to form an integral patient interface.

[0594] In the previous embodiments, flushing of the anatomical dead space was provided by accelerating breathing gas through the flushing flow cavity and into the patient's nares. In the mask 810, flushing of the anatomical dead space may occur in different ways, as shown in the scenarios depicted in FIGS. 45-47. The first scenario, shown in FIG. 45, represents when the patient exhales through their nose with their mouth open. According to this scenario, at the end of exhalation, fresh, pressurized breathing gas enters the patient's mouth from the primary flow cavity 636 via the mouth opening 624. It then flows into the throat, ascends through the nasal passages, and exits the nares into the exhaust cavity 940 and into the atmosphere through the bias vent holes 852. The flow of fresh breathing gas entering the mouth and exiting the nares has the effect of flushing the anatomical dead space by removing any carbon dioxide-rich exhaled breathing gas remaining in the throat and nasal passages at the end of the exhalation phase.

[0595] FIG. 46 illustrates another scenario in which flushing of an anatomical dead space may occur when a patient's mouth is closed. (Although FIG. 46 is a schematic cross-sectional view and appears to show the patient's mouth open, it should be read as if the patient's mouth is closed.) During a nose exhale and mouth closure, fresh pressurized breathing gas enters primary flow cavity 636 and travels between cavity wall 634 and the portion of seal member 622 that contacts the patient's upper lip. In the absence of such a portion, the patient's upper lip would form the side of a flow path such that during a nose exhale and mouth closure, fresh pressurized breathing gas would enter primary flow cavity 636 and travel between cavity wall 634 and the patient's upper lip. Because this flow path has a small cross-sectional area, the velocity of the breathing gas increases, thereby forming a jet of breathing gas that enters the patient's nasal passages, mixes with the exhaled breathing gas, and flushes the carbon dioxide-laden anatomical dead space due to the combination of increased velocity and turbulence of the gas entering the patient's nares. Exhaled breathing gases enter exhaust cavity 940 and exit to the atmosphere via bias vent hole 652.

[0596] Figure 47 illustrates a third scenario in which flushing of the anatomical dead space is believed to occur when the patient exhales through the mouth. In this scenario, carbon dioxide-rich exhaled breathing gases are expected to fill the nasal passages. However, the mask 810 prevents the exhaled air from passing through the mouth. During breathing, fresh, pressurized breathing gas enters the primary flow cavity 636 and travels between the cavity wall 634 and the patient's upper lip. As described above, this flow path has a small cross-sectional area, increasing the velocity of the breathing gas, thereby forming a jet of breathing gas. A portion of the jet enters the patient's nasal cavity, mixes with the exhaled breathing gas, and flushes out carbon dioxide-rich anatomical dead spaces. However, another portion of the jet flows over the rim 708 of the cavity wall 634 into the exhaust cavity 940, which is believed to create a venturi effect that draws gas from the nasal cavity, including at least a portion of the exhaled breathing gas. Exhaled breathing gas from the nasal cavity and from the primary flow cavity enters the exhaust cavity 940 and exits to the atmosphere through the bias vent hole 652.

[0597] In each of these three scenarios, breathing gas is supplied through a single inlet to the primary flow cavity 636. The single inlet, i.e., primary flow path inlet 680, is formed as a large, circular opening to reduce flow resistance so that the pressure therapy received by the patient is not compromised. The constant availability of fresh, pressurized breathing gas supplied in the current embodiment is believed to cause flushing of anatomical dead spaces whether the mouth is open or closed, and whether the patient exhales through the mouth, nose, or both.

[0598] As with the other embodiments described above, the mask frame 870 may be permanently connected to the cushion module 620. This may be achieved by any suitable connection known to those skilled in the art of patient interfaces, such as snap-fit ​​features or welding. Alternatively, the mask frame 870 may be releasably connected to the cushion module 620 to allow for separation and cleaning of the mask frame 870 and cushion module 620 for cleaning and part replacement. Again, this may be achieved by any suitable connection known to those skilled in the art of patient interfaces, such as a snap-fit, push-fit, or interference fit.

[0599] A further embodiment of a patient interface 1010 is shown in Figures 50-70. This is a variation of the mask 810 shown in Figures 43-49, but the respiratory gas flow and dead space flushing features remain the same as those described above with reference to Figures 45-47. The patient interface 1010 includes a cushion module 1012, a frame 1014, and a conduit connector 1016 including an elbow 1130 and a socket insert 1150.

[0600] Cushion module 1012 (FIGS. 50-52, 54, 61, and 62) is a variation of cushion module 620 shown in FIGS. 30-35C. Cushion module 1012 includes a seal member 1020 secured to a housing 1080 to define an interior volume. The interior volume is divided into first and second cavities by a cavity wall 1050. The first cavity is a main flow cavity 1032, and the second cavity is an exhaust flow cavity 1030 (also referred to herein as the exhaust cavity). Housing 1080 and seal member 1020 are secured together by overmolding. Seal member 1020 is formed of a soft, resilient material such as silicone. It includes a mouth opening 1028 that circumscribes the patient's mouth when worn on a patient, and also includes nasal openings 1024. The seal member 1020 defines a nasal cradle 1022 with a nasal opening 1024 disposed therein.

[0601] As shown in Figures 54-60, the mouth opening 1028 communicates with the main flow cavity 1032 to allow transfer of breathing gas between the main flow cavity 1032 and the patient's mouth for breathing during the breathing cycle and for flushing of dead spaces.

[0602] Nasal openings 1024 are positioned in the seal member 1020 to align with the patient's nares when the patient interface 1010 is worn on the patient, thereby preventing breathing during a breathing cycle. Respiratory gases can be transferred from the primary flow cavity 1032 via nasal outlets 1042 (see FIGS. 56 and 60 ) to the nares through the nasal openings 1024 for ventilation and flushing of anatomical dead spaces. The nasal outlets 1042 are recessed from the nasal openings 1024. The positioning of the nasal outlets 1042 relative to the nasal openings 1024 allows excess respiratory gases from the primary flow cavity 1032 to pass to the exhaust flow cavity 1030 and be exhausted to the environment through vent openings 1090 in the housing 1080. The nasal openings 1024 are defined by a rim 1034 on the outer surface of the seal member 1020. However, considering that the nasal outlets 1042 and the openings to the exhaust flow cavity 1030 are recessed from the rim 1034, the nasal openings 1024 include a volume between the level of the rim 1034 and the combined opening formed by the nasal outlets 1042 and the openings to the exhaust flow cavity 1030. It is through this volume, i.e., the nasal openings 1024, that breathing gases can flow from the primary flow cavity 1032 to the exhaust flow cavity 1030. In other words, flow between the primary flow cavity and the exhaust cavity occurs over an edge of the cavity wall. This edge is located distal to the gas inlet opening and proximal to the nasal opening. The deformation region is configured to maintain a spaced-apart relationship between this edge of the cavity wall and the nasal opening.

[0603] A bead 1036 circumscribes a rim 1034 on the inner surface of the seal member 1020. The bead 1036, in this embodiment, includes a region of increased wall thickness, as shown in FIG. 58. The increased thickness of the rim 1034 increases the resistance of the rim 1034 to blowout when the patient interface 1010 receives pressurized breathing gas from the flow generator. The increased thickness of the rim 1034 also increases the resistance of the rim 1034 to undesirable deformation that may occur when the patient interface 1010 is applied to a patient.

[0604] The seal member 1020 also includes a cavity wall 1050 (shown in FIGS. 54-58 and 60) that divides the cushion module 1012 internally to define a primary flow cavity 1032 and an exhaust flow cavity 1030. However, the cavity wall 1050 is positioned to allow breathing gas to flow from the primary flow cavity 1032 to the exhaust flow cavity 1030. The exhaust flow cavity 1030 is positioned at an upper portion of the interior volume of the seal member 1020 (see FIG. 54). The primary flow cavity 1032 constitutes a lower portion of the interior volume of the cushion module 1012.

[0605] The cavity wall 1050 is configured to allow preferential deformation of the cavity wall 1050 in a manner that reduces the likelihood of blockage of the exhaust flow cavity 1030 and the nasal openings 1024. In this embodiment, the cavity wall 1050 is connected to a wall portion 1026 of the seal member 1020 between the nasal openings 1024 and the mouth opening 1028 by a connecting member 1062 (see FIGS. 54-58 ). The connecting member 1062 directs forces applied to the wall portion 1026 to the cavity wall 1050 where the deflecting force is absorbed. In doing so, the connecting member 1062 substantially maintains the position of the cavity wall 1050 relative to the nasal openings 1024 and the wall portion 1026. Another way to understand the effect of the connecting member 1062 is to understand it as clamping the cavity wall in place against the wall portion 1026. This allows patient treatment to continue with minimal interference with (a) the flow of respiratory gas through the nasal outlets 1042, (b) the flow of respiratory gas through the nasal openings 1024, and (c) the flow of respiratory gas through the exhaust flow cavity 1030.

[0606] The connecting member 1062 functions similarly to the tether 710 described above and shown in FIG. 37. That is, the connecting member 1062 tightens the cavity wall 1050 such that the spacing of the wall portion 1026 from the cavity wall is substantially maintained when a deforming force is applied to the wall portion 1026. This reduces the likelihood of occlusion of the nasal outlet 1042. This substantially fixed spacing also acts in the other direction, preventing ballooning of the wall portion 1026 away from the cavity wall 1050. Blowout is inhibited by the connection of wall portion 1026 to cavity wall 1050. Additionally, connecting member 1062 concentrates deformation forces on cavity wall 1050, which is designed to deform preferentially away from nasal openings 1024 so that deformation is less likely to occlude nasal openings 1024.

[0607] The deformation absorption effect is illustrated in Figures 59A-59C, which also show that the cavity wall 1050 includes a deflector panel 1052, a side panel 1054, a main panel 1056, and a deformation region 1074 connecting the side panel 1054 and the main panel 1056. The deformation region 1074 includes first and second resilient regions 1058, 1060 and first and second walls 1066, 1068. The deformation panel 1064 includes a first wall 1066 protruding from the first resilient region 1058 (see Figure 58), a second wall 1068 extending from the second resilient region 1060, and a connector 1070 connecting the first wall 1066 to the second wall 1068. The connecting portion 1070 has a curved profile that, in a resting state, matches the first direction of the first wall 1066 and matches the end of the second wall 1068 away from the second elastic region 1060.

[0608] The deformation region 1074 structurally decouples the deflector panel 1052 from the main panel 1056. The decoupling occurs because the deformation panel 1064 accommodates the reduced distance between the first and second resilient regions 1058, 1060.

[0609] Deformation of the deforming panel 1064 occurs in two stages. In the first stage, as the second elastic region initially displaces toward the first elastic region, the first wall folds around its connection line with the first elastic region until it contacts or is adjacent to the underside of the first elastic region. At this point, there is still a gap between the first and second elastic regions 1058, 1060 because the length of the second wall 1068 is longer than the length of the first wall 1066. In the second stage of deformation, as the second elastic region 1060 approaches the first elastic region 1058, the second wall 1068 buckles and translates over the first wall 1066 until it contacts or is adjacent to the first elastic region 1058 (as shown in FIG. 59C ). This buckling and translational movement is sometimes referred to as "rolling." Buckling occurs due to the curvature of the second wall 1068 and the longer length of the second wall 1068 compared to the first wall 1066. In particular, as shown in FIG. 59B, the bending point farthest from the second elastic region is the connecting portion 1070. However, once the first wall 1066 reaches its limit in accommodating the displacement of the second elastic region 1060, the position of the connecting portion 1070 becomes fixed, and further movement of the second elastic region 1060 toward the first elastic region 1058 causes the second wall 1068 to adopt an increased curvature and buckle. The increased curvature causes the second wall 1068 to adopt a U-shape with the bending point shifting from the connecting portion 1070 to a position along the second wall 1070 away from the connecting portion 1070. When the second resilient region 1060 contacts the first resilient region 1058, the bending point shifts along the second wall 1068 such that a portion of the second wall 1068 extends beyond the bending point. In other words, as the second wall 1068 buckles and translates over the first wall 1066, the length of the second wall 1068 beyond the bending point increases and the length of the second wall 1068 behind the bending point decreases.

[0610] Depending on the shape and wall thickness of the first and second walls 1066, 1068, buckling and translation of the second wall 1068 may occur before the connecting portion 1070 is secured, however, the effect of the bending point shifting (and therefore the effect of changing the length of the second wall 1068 beyond the bending point and behind the bending point) remains the same.

[0611] 55 and 56, the deflector panel 1052 has an end rim 1053 recessed from the level of the rim 1034 of the nose opening 1024 (indicated by dashed line R in FIG. 55). The deflector panel 1052 is a curved panel. The recessed position of the deflector panel 1052 ensures that it does not touch the patient's septum (which could cause discomfort) and provides a vestibule between the end of the deflector panel 1052 and the rim of the nasal opening for respiratory gas to flow from the primary flow cavity 1032 to the nares or exhaust flow cavity 1030. The preferential deformation of the deformation region 1074 ensures that the vestibule remains even as the seal member 1020 deforms. The deflector panel 1052 is joined at its lower end to the side panel 1054 and slopes upward from there toward the end rim 1053. Positioned adjacent to the deflector panel 1052 is the wall 1026 of the seal member 1020 between the nasal opening 1024 and the mouth opening 1028. The deflector panel 1052 is connected to the inner wall of the seal member 1020 on either side of the nasal opening 1024 beyond the bead 1036. This arrangement avoids further stiffening of the bead 1036 and rim 1034, which may affect patient comfort.

[0612] The seal member 1020 is configured to accelerate breathing gas through the primary flow cavity 1032 and direct the accelerated breathing gas toward the nasal openings 1024. In particular, the deflector panel 1052 and the wall 1026 define a channel that leads to the nasal openings 1024. The channel terminates at a nasal outlet 1042, i.e., is recessed from the nasal openings 1024. The channel tapers the primary flow cavity 1032 formed between the deflector panel 1052 and the wall 1026. In other words, the cross-sectional area formed between the deflector panel 1052 and the wall 1026 in the primary flow cavity 1032 decreases as it leads to the nasal openings 1024. This taper accelerates the flow of breathing gas through the channel. Depending on the point in the respiratory cycle, the accelerated breathing gas enters the nares to provide flushing of anatomical dead spaces.

[0613] As with the other embodiments, an accelerated stream of breathing gas is delivered to the patient to provide flushing of anatomical dead spaces. The method according to this embodiment includes delivering breathing gas at an elevated pressure to a primary flow cavity 1032 of the cushion module 1012. The primary flow cavity 1032 defines a first cavity. As described above, the primary flow cavity 1032 supplies breathing gas to the patient's mouth and nares. This embodiment differs in that the flow of breathing gas to the nares is accelerated through a portion of the primary flow cavity, namely, a portion of the primary flow cavity 1032 between the deflector panel 1052 and the wall 1026, which decreases in cross-sectional area toward the nasal openings 1024. In this manner, accelerated breathing gas can be delivered to the patient's nares. The accelerated flow of breathing gas occurs simultaneously as breathing gas is available from the primary flow cavity 1032 for delivery to the mouth.

[0614] In this embodiment, the method further includes exhausting breathing gas from an exhaust flow cavity 1030 in the cushion module 1012. The exhaust flow cavity 1030 defines a second cavity. The exhaust flow cavity 1030 is in fluid communication with the primary flow cavity 1032. In effect, exhaled breathing gas from the mouth and excess breathing gas in the primary flow cavity flow into the exhaust flow cavity 1030 due to their fluid communication. Additionally, exhaled breathing gas from the nares flows into the exhaust flow cavity 1030. In this embodiment, fluid communication between the primary flow cavity 1032 and the exhaust flow cavity 1030 is enabled by the recessed position of the cavity wall 1050 relative to the rims 1034 of the nasal openings 1024 and the vestibule formed when the cushion module 1012 is worn such that the patient's nares are positioned over the nasal openings 1024.

[0615] The side panels 1054 extend around the lower edge of the deflector panel 1052 and extend laterally outward to join with the inner sidewall of the seal member 1020. The lateral sides of the side panels 1054 also extend upwardly concavely from the deflector panel 1052. extend upward from a connection line with the housing 1080. In this embodiment, the housing 1080 includes a series of interior overmolded windows 1092 (see FIGS. 63 and 64 ) through which the main panel 1056 is overmolded with the housing 1080 when the seal member 1020 is overmolded with the housing 1080 to form the cushion module 1012. The material used to form the seal member 1020 flows through the overmolded windows 1092 during molding such that the material takes the shape of the housing 1080 and the windows 1092 before solidifying or curing. The material extending through the windows 1092 provides a mechanical connection with the housing. The windows 1092 may take the form of openings that extend completely through the housing 1080.

[0616] A deformation region 1074 connects the side panel 1054 to the main panel 1056. It includes first and second resilient regions 1058, 1060 ( FIG. 60 ) and a deformation panel 1064 that includes first and second walls 1066, 1068. The first resilient region 1058 connects the deformation region 1074 to the end wall. It has a generally polygonal profile, with a contour similar to the concave contour of the main wall. In this embodiment, the first resilient region 1058 blends smoothly with the main wall as it extends laterally toward the side of the seal member 1020.

[0617] The second resilient region 1060 abuts the lower end of the deflection panel 1064 and is elongated. It is disposed generally parallel to the first resilient region 1058. The second resilient region 1060 is at least as wide as the nasal opening 1024. It has this configuration to function as a load distributor for forces transmitted through the connecting member 1062. However, in other embodiments, it can be wider than the nasal opening 1024. In this embodiment, the second resilient region 1060 is formed as a rib and has discrete ends, but in other embodiments, it can smoothly taper toward the side panel 1054. The connecting member 1062 extends from the connecting line (A in FIG. 55) to the connecting line (B in FIG. 57) at the wall portion 1026 and is located below the second resilient region 1060. The connecting member 1062 increases the resilience (i.e., stiffens) of this region of the cavity wall 1050. Thus, a force applied to the wall 1026 in the direction of the housing 1080 is transmitted to the second resilient region 1060, which is urged toward the first resilient region 1058. However, the first and second resilient regions 1058, 1060 are configured to encourage deformation of the deflection panel 1064, rather than deformation of the main panel 1056, the side panel 1054, or the deflector panel 1052.

[0618] 59A-59C show the sequence of initial and subsequent deformation of the seal member 1020 as a deforming force is applied via the walls 1026. The patient interface 1010 is shown in a resting state in FIG. 59A with the first and second resilient regions 1058, 1060 spaced apart. When a force is applied via the connecting member 1062, the deformation is absorbed by deformation of the first and second walls 1066, 1068 due to the relatively thin wall thickness of the first and second walls 1066, 1068 compared to the relatively thick wall thickness of the first and second resilient regions 1058, 1060. This occurs by initially folding the first wall 1066 under the first resilient region 1058 as the spacing between the first and second resilient regions 1058, 1060 decreases (as shown in FIG. 59B). As the spacing is further reduced by additional deformation applied through wall portion 1026 and connecting member 1062, first wall 1066 folds flat against the underside of first resilient region 1058, and second wall 1068 buckles and rolls over first wall 1066 (as shown in FIG. 59C). This rolling action continues until first resilient region 1058 abuts second resilient region 1060.

[0619] The first wall 1066 extends below the level of the first resilient region 1058. In the file, the angle between the underside of the first resilient region 1058 and the first wall 1066 ranges from 5° to 135° at rest. However, in the embodiment shown in FIGS. 50-70, the angle at rest is 85°. It has a contour that follows the contour of the first resilient region 1058 and tapers inward toward its end. As a result of the taper, an imaginary line tracing the intersection of the first resilient region 1058 and the first wall intersects an imaginary line tracing the line of the connection portion 1070 at the pivot point (P in FIG. 58). The first wall 1066 has a length in the range of 1 mm to 10 mm, optionally in the range of 2 mm to 5 mm. The first wall 1066 has a thickness in the range of 0.15 mm to 1 mm. This thickness is constant along the width and length of the first wall 1066. To ensure that the first wall 1066 deforms in preference to the first elastic region 1058, the first elastic region 1058 has a wall thickness that is at least three times the wall thickness of the first wall 1066.

[0620] The connecting portion 1070 is located at the end of the first wall 1066 away from the first resilient region 1058, and the second wall 1068 extends from the second resilient region 1060 to meet the connecting portion 1070. In the current embodiment, both the connecting portion 1070 and the second wall 1068 follow the concave contour of the first wall 1066. The second wall 1068 initially extends from the second resilient region 1060 in a direction that is sloped downward from a plane that intersects the second resilient region 1060 and the curved corner 1070. However, the second wall 1068 curves upward, away from the second resilient region, to meet the connecting portion 1070. Additionally, the second wall 1068 tapers in thickness, increasing from the connecting portion 1070 toward the second resilient region 1060. Both the curve and taper of the second wall 1068 cause the initial deformation of the deforming panel 1064 to be accommodated by the first wall 1066, and further deformation to be accommodated by the second wall 1068 buckling and rolling over the first wall 1066.

[0621] Second wall 1068 has a length ranging from 2 mm to 15 mm. Optionally, the length is within the range of 2 mm to 10 mm. In the embodiment shown in FIGS. 50-70, second wall 1068 has a length of 5 mm. This length can vary depending on the amount of travel required to accommodate deformation of seal member 1020. The thickness of second wall 1068 can vary from 0.15 mm where it joins curved corner 1070 to 2 mm where it joins second resilient region 1060. In the illustrated embodiment, the thickness ranges from 0.27 mm to 0.4 mm.

[0622] The shape of the first and second walls 1066, 1068 and their thicknesses are selected to allow the cushion module 1012 to accommodate a wide range of facial shapes and deformation forces associated with the application and use of the patient interface. However, different cushion modules can be manufactured to accommodate a range of facial shapes that fall towards either end of the facial shape spectrum.

[0623] The first and second resilient regions 1058, 1060 are formed with a greater wall thickness to provide greater resiliency compared to the deformation panel 1064; this is done so that a single material can be used to form the seal member 1020. However, it will be understood that the first and second resilient regions 1058, 1060 may be made more rigid by alternative means, provided that the deformation panel 1064 preferentially deforms when a force is applied to the seal member 1020. For example, the first and second resilient regions 1058, 1060 may be formed of a more resilient material (such as a different grade of silicone or plastic material) or may have a different construction.

[0624] The housing 1080 (shown in more detail in Figures 61-65) has a body 1082 with front and rear faces 1112, 1114. The rear face contains the main flow cavity 1032 and the exhaust flow The housing 1080 and the seal member 1020 are overmolded with the windows to form a permanent mechanical connection and seal between the housing 1080 and the seal member 1020. The periphery of the body 1082 includes outwardly projecting tab members 1084 and beads 1036 disposed at the ends of the tab members 1084 and defining a series of outer overmolded windows or openings 1088. The seal member 1020 is overmolded with the windows to form a permanent mechanical connection and seal between the housing 1080 and the seal member 1020.

[0625] As explained above, an inner overmolded window 1092 (FIGS. 63 and 64) is formed in the housing 1080 in a U-shaped configuration extending across the body 1082. The inner overmolded window 1092 extends from the outer overmolded window 1088 across the top of the body 1082 and back to it. A group of vent openings 1090 are located within the area bounded by the inner overmolded window 1092 to allow breathing gas to be exhausted from the exhaust flow cavity 1030 to the ambient.

[0626] The pressure port 1094 is located laterally on the underside of the body 1082, and the breathing gas inlet opening 1096 is located at a central location on the underside of the body 1082. The inlet opening 1096 is adapted to connect the frame 1014 and conduit connector 1016 with the cushion module 1012. In particular, the inlet opening 1096 is defined by a sleeve 1098 having an inner end wall 1100 and an outer end wall 1102. The outer end wall 1102 has a pair of laterally opposed arcuate flanges 1104 that are spaced apart to define upper and lower recesses 1106 therebetween.

[0627] The recess 1106 serves as a critical feature because it helps to keep the frame 1014 and socket insert aligned with the cushion module 1012. Specifically, the conduit connector 1016 plugs into the inlet opening 1096, capturing the frame 1014 between the conduit connector 1016 and the housing 1080. In addition to controlling alignment, this arrangement allows the conduit connector 1016 and frame 1014 to be disengaged and reassembled from the cushion module 1012 whenever necessary.

[0628] The conduit connector 1016 includes an elbow 1130 (FIGS. 53 and 54) and a socket insert 1150 (FIGS. 53, 54, 69, and 70). One end of the elbow 1130 is a tapered connection that can be connected to a breathing gas flow conduit from a flow generator or ventilator. The other end of the elbow 1130 has a channel 1140 that connects the tapered connection to a neck 1138, which in turn transitions into a ball element 1134. The outer surface of the ball element 1134 is shaped as a spherical segment.

[0629] The socket insert 1150 has an annular flange 1152 with an inwardly tapering inner wall 1154. The inner taper cooperates with the neck portion 1138 and ball element 1134 of the elbow 1130 to provide free rotational movement in both the vertical and horizontal directions. The socket insert 1150 also has an outer wall 1156 defining a first lip 1162 that includes a feature 1158 that interacts with the recess 1106 in the mask housing 1080 to limit rotational movement of the socket insert 1150 and frame 1014 relative to the housing 1080. The socket insert 1150 further has two fingers 1160 (FIGS. 69 and 70) extending axially from the flange 1152. Each finger 1160 has an outer wall 1156 having a shape corresponding to the shape of the inside of the sleeve 1098 and an inner wall 1168 having a shape corresponding to the outer surface of the ball element 1134, so that the fingers 1160 collectively define a socket for the ball element 1134. An arcuate flange portion 1170 is disposed at the end of each finger 1160 and defines a second radially projecting lip 1172.

[0630] In the assembled patient interface 1010, the socket insert 1150 is inserted into the frame as part of the interference fit between the conduit connector 1016 and the housing 1080. 1014 is sandwiched against the housing 1080. This is made possible by the shape of the frame 1014, as shown in FIGS. 54 and 66-68. Specifically, the frame 1014 has a body 1110 that is generally shaped to follow the contours of the cushion module 1012. The frame 1014 allows the patient interface 1010 to be connected to headgear that holds the patient interface 1010 in place during treatment. To this end, the frame 1014 includes upper and lower headgear connection points 1116. Standard headgear connections can be used to connect the headgear. In this embodiment, the headgear connection points 1116 include upper and lower pairs of openings on the sides of the frame 1014.

[0631] The frame 1014 includes a conduit opening 1122 through which the conduit connection 1016 passes for connection to the housing 1080. To facilitate this, the frame 1014 includes the conduit opening 1122 recessed from the front face 1112 and having a stepped profile (see FIG. 68 ) defining opposed arcuate shoulders 1126 to define upper and lower recesses 1128 therebetween. The innermost periphery of the conduit opening 1122 is sized to fit around the inlet opening 1096 of the housing 1080. When assembled with the cushion module 1012, the recess 1128 is shaped to receive the feature 1158 of the socket insert 1150. This interaction between the recess 1128 and the feature 1158 fixes the orientation of the frame 1014 relative to the cushion module 1012.

[0632] However, it will be understood that the frame 1014 may be connected to the housing 1080 by any conventional means, such as by adhesive or welding. The frame 1014 also includes a bias vent opening 1118. At the patient interface, the bias vent opening 1118 aligns with the vent opening 1090 in the housing 1080 to allow exhaust breathing gases from the exhaust flow cavity 1030 to be vented to the environment without interference from the frame 1014.

[0633] This embodiment includes a frame 1014, however in alternative embodiments, the headgear connection points may be integral with or connected to the housing 1080. In that case, the frame 1014 is not necessary and may be omitted in such embodiments.

[0634] As shown in FIG. 54 , the conduit connector 1016 and frame 1014 are assembled to the housing 1080 by fitting the fingers 1160 of the socket insert 1150 through the sleeve 1098 so that the second lip abuts the inner end wall 1100. This involves positioning the frame 1014 between the socket insert 1150 and the housing 1080 and aligning the features of the socket insert 1150 with the recesses in the frame 1014 and the housing 1080. The socket insert 1150 is then pressed into the inlet opening 1096 until the second lip abuts the inner end wall 1100. The elbow 1130 is connected to the cushion module 1012 by inserting the ball element 1134 into the socket insert 1150, as shown in FIG. 54 .

[0635] In an alternative embodiment, a cushion module 1212 (FIG. 71) is provided in a similar form to cushion module 1012 but adapted to receive a larger conduit connector 1016.

[0636] Similar to cushion module 1012, cushion module 1212 includes a housing 1280 and a seal member 1220. Housing 1280 includes a tab member 1284, a bead 1286, an outer overmolded window 1288, and a pressure port 1294, which are the same as their counterparts in cushion module 1012. A description of these features with respect to cushion module 1012 is provided in conjunction with the cushion shown in FIGS. The same applies to the corresponding features of cushion module 1212. However, in housing 1280, inlet openings 1296 are centrally located and extend a short distance from outer overmold window 1288. In contrast to cushion module 1012, bias vent openings 1290 are grouped on each side of inlet opening 1296. This is a result of the inlet openings 1296 extending across the top of housing 1280 close to outer overmold window 1288. Inner overmold windows 1292 form a boundary with outer overmold window 1288 around each group of bias vent openings 1290. In this embodiment, inner overmold windows 1292 are arranged in a W-shape. This shape results in a corresponding W-shaped inner overmold 1240 of seal member 1220, as seen in FIG. 71 .

[0637] However, it will be understood that the inner overmold window 1292 may alternatively be formed in two separate V- or U-shaped arrangements extending around each group of bias vent openings 1290. Other embodiments may have different arrangements of the bias vent openings 1290, resulting in different shapes defined by the inner overmold window 1292.

[0638] Cushion module 1212 includes a cavity wall 1050 including deflector panels 1052, side panels 1054, and deformation regions 1074 that are the same as their counterparts in cushion module 1012. The descriptions of these features with respect to cushion module 1012 apply equally to cushion module 1212, with corresponding features shown in FIG. 72. However, instead of having a main panel 1056 that contacts housing 1280 along a U-shaped line of contact that follows inner overmolded window 1092, the main panel 1056 of cushion module 1212 follows a W-shaped line of contact with housing 1280. As a result, the main panel 1056 extends downward from first resilient region 1058 more deeply at the side regions of the end walls than at the center of the main panel 1056.

[0639] In further alternative embodiments, the main panel 1056 may be formed without being overmolded onto the housing 1280, such that the inner overmold 1240 is omitted. In such embodiments, the bias vent openings 1290 may be formed in the seal member 1220 rather than the housing 1280, such that the main panel 1056 interfaces with the seal member 1220. Instead, the main panel 1056 may abut or interact with the housing 1280 to form a seal, for example, by bonding or welding.

[0640] To accommodate the configuration of the housing 1280, the frame 1014 is replaced with a reconfigured frame 1614 ( FIG. 75 ). The frame 1614 includes upper and lower headgear connection points 1616, pressure port openings 1620, conduit openings 1622, and recesses 1628 that are the same as their counterparts in the frame 1014. The descriptions of these features with respect to the frame 1014 apply equally to the frame 1614, and corresponding features are shown in FIG. 75 . However, the frame 1614 differs in that the bias vent opening 1618 is located to the side of the conduit opening 1622 and aligns with the bias vent opening 1290 of the housing 1280 when the frame 1614 is combined with the cushion module 1212.

[0641] Alternative embodiments of the patient interface may be adapted to connect to a flow generator and deliver breathing gas from the flow generator to the cushion module and transfer breathing gas from the cushion module to the flow generator. Patient interfaces configured in this manner are known as dual-limb patient interfaces. They are able to capture and return exhaled breathing gas to the flow generator rather than venting it to the atmosphere. Cut.

[0642] Three different embodiments of a dual limb patient interface are described below, each based on a conduit arrangement concept: coaxial, split inlet, and separate inlet. While these embodiments are described with respect to different cushion modules, it will be understood that the conduit arrangement concept can be adapted to work with other cushion modules disclosed herein or other available or known cushion modules.

[0643] In each of the following embodiments, the bias flow is increased by incorporating a bias leak in the expiratory flow path. The bias leak may be adjustable. Furthermore, the bias leak may be in the range of 5-15 L / m. This leak rate is expected to reduce interference with the operation of a flow generator or ventilator operating in a dual-limb configuration.

[0644] A bias leak is believed to induce a higher bias flow rate, which is expected to improve dead space flushing during use of the patient interfaces disclosed herein. Thus, a bias leak may make the patient interfaces described herein suitable for use with flow generators or ventilators that provide insufficient gas flow rates to perform anatomical dead space flushing in a dual-limb configuration. In other words, the patient interfaces described herein may make some flow generators or ventilators useful for anatomical dead space flushing procedures while operating in a dual-limb configuration.

[0645] One embodiment of a coaxial patient interface 1300 is shown in Figures 76-81. The patient interface includes the cushion module 1012 described above and a frame 1310. The patient interface 1300 includes an inlet pathway 1324 configured to deliver breathing gas to the inlet opening 1096 of the cushion module 1012 and an exhaust pathway 1326 configured to receive breathing gas from the cushion module 1012, wherein the inlet pathway 1324 and the exhaust pathway 1326 are coaxial.

[0646] In the embodiment shown in Figures 76-81, the inlet and exhaust paths 1324, 1326 are defined by a coaxial conduit 1340 having an inner conduit 1342 and an outer conduit surrounding the inner conduit 1342. The inner conduit 1342 has an inner bore 1346, and the outer conduit coaxially surrounds the inner conduit 1342 to define an annular outer bore 1348. In this embodiment, the inner conduit 1342 defines the inlet path 1324, and the outer conduit 1344 defines the exhaust path 1326. This can be switched in other embodiments so that the inner conduit 1342 defines the exhaust path and the outer conduit 1344 defines the inlet path. The conduits can be of any length. Optionally, the length is sufficient to decouple forces between the cushion module 1012 and the inspiratory and expiratory limbs (conduits) of a flow generator or ventilator.

[0647] The coaxial conduit 1340 is connected to a frame 1310 adapted to extend the inlet pathway 1324 to the inlet opening 1096 of the cushion module 1012 and to extend the exhaust pathway 1326 from the bias vent opening 1090 of the cushion module 1012 to the outer conduit 1344. More specifically, the frame 1310 has an inner duct 1316 defining an inner passage 1318 that connects the inlet pathway 1324 of the coaxial conduit 1340 to the inner conduit 1342 to extend the inlet pathway 1324 of the coaxial conduit 1340 to the inlet opening 1096 of the cushion module 1012. This connection is made via an inner conduit connecting flange 1336. The inner duct 1316 interacts with the inlet opening 1096 to deliver breathing gas from the inlet pathway 1324 to the primary flow cavity 1032 of the cushion module 1012. Similarly, the frame 1310 has an outer duct 1320 that surrounds the inner duct 1316 and defines an outer passage 1322 that connects the bias vent opening 1090 to an outer conduit 1344. This connection is This is done via a tube connection flange 1338. In this arrangement, the exhaust path 1326 extends from the cushion module 1012 through the outer passageway 1322 and through the outer bore 1348 of the conduit 1342.

[0648] The outer duct 1320 terminates in a flange 1334 configured to seal the area surrounding the vent opening 1090 with the cushion module 1012. More specifically, the flange 1334 is molded to seal against the outer overmold 1038 of the cushion module 1012. In an alternative embodiment, the flange 1334 may be formed to seal with the inner overmold 1040 and a portion of the outer overmold 1038 to seal the cushion module 1012 and the outer passageway 1322.

[0649] As shown in FIGS. 77 and 78 , the frame 1310 includes a partition wall 1328 including an inner passageway opening 1330 configured to connect the inner passageway 1318 with the primary flow cavity 1032 of the cushion module 1012. The inner passageway opening 1330 is integral with the partition wall 1328 such that a connection is made when the flange 1334 seals against the cushion module 1012. The connection may be maintained by a connector 1380 to provide an interference fit between the frame 1310 and the cushion module 1012. The connector 1380 may be in the form of a socket insert 1150 described above for the patient interface shown in FIGS. 50-70 . However, the connector 1380 may be integrally formed with the partition wall 1328 or may be separately formed in a configuration that allows for connection of the frame to the cushion module 1012.

[0650] While any suitable connection for connecting the frame 1310 to the cushion module 1012 to allow the flow of breathing gas between the cushion module 1012 and the frame 1310 can be used, one option includes an interference-fit connector. For example, the connector can include a series of deformable fingers on the frame 1310 that deflect to pass through the inlet opening 1096 and have a return lip that fits into contact with the inner end wall 1100. Alternatively, the inlet opening 1096 can be formed with features that interlock with corresponding features on the frame 1310. Both features can be designed for an interference fit, a twist-lock fit, a press-fit, a tapered connection, or any other suitable connection that secures the frame 1310 to the cushion module 1012.

[0651] The partition wall 1328 also includes an exhaust pathway opening 1332 that opens into the outer passageway 1322. The flow of breathing gas into the cushion module 1012 through the inner passageway opening 1330 and the flow of breathing gas from the cushion module 1012 into the exhaust pathway opening 1332 are indicated by respective arrows in FIG.

[0652] At the other end of the coaxial conduit 1340 (away from the frame), a coaxial conduit connector 1360 in the form of a distributor connects separate, spaced-apart inspiratory and expiratory limbs of a flow generator or ventilator to the coaxial conduit 1340. The connector is configured to couple the inner conduit 1342 to the inspiratory limb and the outer conduit 1344 to the expiratory limb. More specifically, the connector has an outer conduit connector 1362 and an inner conduit connector 1364 to form these connections. The inner conduit connector 1364 is shaped as a funnel that transitions the flow of breathing gas from the inspiratory limb to the inner bore 1346 of the inner conduit 1342. Both the inner and outer conduit connectors 1362, 1364 have standard profile sizes and shapes for connecting with the inspiratory and expiratory limbs of a flow generator. 76, 78, 80 and 81, the inner conduit connector 1364 is continuous with the coaxial conduit 1340. However, the outer conduit connector 1362 branches off from the side of the coaxial conduit connector 1360. The angle of the outer conduit connector 1362 relative to the inner conduit connector 1364 is: This results in a sharp change in direction of the exhaust path 1326.

[0653] The outer conduit connector 1362 includes an integral loop 1372 that may interact with the expiratory limb. As shown in Figures 80 and 81, the loop is integrated into the outer surface of the outer conduit connector 1362.

[0654] The coaxial conduit connector 1340 includes a bias flow vent 1368 configured to vent gas from the expiratory path to ambient atmosphere. The bias flow vent 1368 may be adjustable to vary the flow of respiratory gas to ambient atmosphere. For example, the flow may be adjusted to a range of 5-15 L / m. In this embodiment, leakage through the bias flow vent 1368 is on the order of 10 L / m. The bias flow vent 1368 may include a filter to reduce infection risks associated with leaked respiratory gas.

[0655] Additionally, the bias flow vent 1368 may be configured to prevent connection to another conduit. Such a connection could prevent the flow of respiratory gas through the bias flow vent 1368, thus reducing the dead-space flushing effect provided by the patient interface. To address this, the bias flow vent 1368 includes one or more features that visually indicate that a removable conduit should not be connected to the bias flow vent 1368. The one or more features prevent a sealing connection with the removable conduit or prevent blockage of the bias flow vent. In this embodiment, the features include three recesses 1370 formed in the end rim of the bias flow vent 1368.

[0656] As an alternative or in addition to recess 1370 , bias flow vent 1368 may have a non-standard size or shape such that a removable conduit cannot be connected to bias flow vent 1368 .

[0657] An alternative embodiment of a dual limb patient interface 1400 is shown in Figures 82-85 and includes a cushion module 620, as shown in Figures 30-34. The description above relating to the cushion module 620 here applies equally to this embodiment.

[0658] The patient interface 1400 includes a frame 1410 adapted to connect with the inspiratory and expiratory limbs of a flow generator. The frame 1410 includes a body 1412 having upper and lower headgear connector points 1414. In this embodiment, the dual limb aspect is provided by the frame 1410 having an inspiratory conduit 1422 configured to deliver breathing gas to the primary flow cavity 636 of the cushion module 620 and an expiratory conduit 1418 configured to receive breathing gas from the cushion module 620. These conduits 1418, 1422 are partially separate channels within the single conduit 1416 and define respective inlet and outlet channels 1420, 1424 that are partially separate channels within each separate conduit 1418, 1422.

[0659] 82 and 85, in the single conduit 1416, the channels 1420, 1424 are separated by a common partition wall 1432. However, as the channels 1420, 1424 extend away from the cushion module end of the frame 1410, they diverge into separate conduits, namely an inhalation conduit 1422 and an exhalation conduit 1418. The inhalation conduit 1422 associated with the inlet channel 1420 is connectable to the inhalation limb of a flow generator or ventilator, and the exhalation conduit 1418 associated with the outlet channel 1424 is connectable to the exhalation limb of a flow generator or ventilator. As with the coaxial conduit embodiment described above, the inhalation and exhalation conduits 1418, 1422 respectively communicate with the cushion module 620 and the inhalation and exhalation conduits. It has sufficient length to provide a force isolation between the air rim.

[0660] As shown in FIGS. 83 and 84 , the inlet and outlet conduits 1420, 1424 terminate in a combined opening 1426 at the cushion module end of the frame 1410. A divider wall 1432 terminates in a cross member 1434 that extends across the combined opening 1426 of the single conduit 1416. While the divider wall 1432 is shown extending across the single conduit 1416, in alternative embodiments, the frame 1410 may include a cross member 1434 that extends across the combined opening 1426 such that the divider wall 1432 intersects with the cross member 1434 of the frame 1416 to separate the inlet channel 1420 from the outlet channel 1424. In either case, the divider wall 1432 and the cavity wall 634 of the cushion module 620 separate the inlet channel 1420 from the outlet channel 1424. In one option, the partition wall 1432 and the cavity wall 634 of the cushion module 620 interact with each other to form a seal separating the inlet channel 1420 from the outlet channel 1424. In this embodiment, as shown in Figures 84 and 85, the interaction involves an edge of the partition wall 1432 being received in a groove along the edge of the cross member 1434. However, it will be understood that alternative embodiments involving other forms of interaction that result in a seal between the partition wall 1432 and the cavity wall 634 are similarly suitable.

[0661] The compound opening 1426 is bounded by a mating member 1438 configured to couple the single conduit 1416 to a sleeve portion 1436 of the frame 1410. The sleeve portion 1436 is configured to connect the frame 1410 to the cushion module 620. The sleeve portion 1436 is adapted to cooperate with the upper and lower rims 720, 722 of the opening 654 of the cushion module 620 to couple the frame to the cushion module 620. The sleeve portion 1436 is configured to releasably couple the single conduit 1416 to the cushion module 620. Such coupling may be enabled by friction or interference fit features interacting with the upper and lower rims 720, 722. The single conduit 1416 may be formed with friction or interference fit features that enable releasable coupling with the sleeve 1436. Alternatively, the single conduit 1416 may be glued or welded to the sleeve 1436, or secured by other means, such as a permanent bond.

[0662] Although not shown in the drawings, the outlet channel 1420 includes a bias flow vent of the type described above with respect to the embodiment including the coaxial conduit.

[0663] An alternative dual limb arrangement for coupling one of the cushion modules disclosed herein to a dual limb flow generator or ventilator includes separate conduits that connect separately to the cushion modules.

[0664] 86 and 87, in which a patient interface 1500 includes the cushion module 1012 shown in Figures 61 and 62 and a frame 1510 incorporating two separate conduits 1520, 1530. More specifically, the frame 1510 includes a first conduit 1520 configured to deliver breathing gas to a primary flow cavity 1032 of the cushion module 1012 and a second conduit 1530 configured to receive breathing gas from the cushion module 1012, the first and second conduits 1520, 1530 being spaced apart.

[0665] In this embodiment, the first conduit 1520 is configured to open into the main flow cavity 1032, and the second conduit 1530 is configured to open into the exhaust flow cavity 1030. To accommodate this arrangement, the frame 1510 has separate respective openings through which the first and second conduits 1520, 1530 pass.

[0666] In this embodiment, both conduits 1520, 1530 have the form of a conduit connector 1016 that includes an elbow 1130 and a socket insert 1150, as shown in Figures 50-54. The frame 1510 is adapted to accommodate this stacked arrangement of the conduits 1520, 1530. However, in a variation of this embodiment, one or both of the two conduits 1520, 1530 do not have the socket insert 1150 and elbow 1130 that would allow rotational movement of the conduits 1520, 1530 relative to the cushion module 1012. In other words, one or both of the conduits 1520, 1530 may be coupled to the cushion module 1012 in a fixed orientation and / or position.

[0667] Similar to the coaxial and split inlet embodiments, the exhaust conduit 1530 includes a bias flow vent for exhausting breathing gases to the environment.

[0668] Those skilled in the art of the present invention will appreciate that many variations or modifications can be made to the preferred embodiments without departing from the spirit and scope of the present invention.

[0669] Although a number of specific device and method embodiments have been described, it should be understood that the devices and methods can be embodied in many other forms, for example, features of one embodiment can be combined with features of one or more other embodiments to achieve further embodiments.

[0670] In the following claims and the preceding description, unless the context requires otherwise, either by express language or necessary implication, the word "comprise" and variations such as "comprises" or "comprising" are used in their inclusive sense, i.e., to specify the presence of stated features but do not exclude the presence or addition of further features in various embodiments of the apparatus and methods disclosed herein.

[0671] In the foregoing description of the preferred embodiment, specific terminology has been used for the sake of clarity. However, it is understood that the present invention is not intended to be limited to the specific terminology so selected, and that each specific term includes all technical equivalents that operate in a similar manner to achieve a similar technical purpose. Terms such as "front" and "back," "inner" and "outer," "superior," "lower," "upper" and "lower," "above" and "belower," etc., are used as convenient terms to provide points of reference and are not to be construed as limiting terms. The terms "vertical" and "horizontal," as used in connection with the patient interface throughout this specification, including the claims, refer to orientations relative to the normal operating orientation.

[0672] Reference herein to any prior publication (or information derived therefrom) or known matter is not, and should not be taken as, an acknowledgment, admission, or in any way suggestion that the prior publication (or information derived therefrom) or known matter forms part of the common general knowledge in the field of endeavor to which this specification pertains.

[0673] Furthermore, while the present invention has been described in connection with what are presently considered to be the most practical and preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements falling within the spirit and scope of the invention. Also, the various embodiments described above may be practiced in combination with other embodiments, for example, aspects of one embodiment may be combined with aspects of another embodiment to achieve yet another embodiment. Furthermore, each independent feature or component of any given assembly may constitute an additional embodiment.

Claims

1. a cushion module for a patient interface, the cushion module including a first cavity, a second cavity, a nasal opening, and a mouth opening; (a) the first and second cavities are separated by a cavity wall that, in use, allows breathing gas to flow within the cushion module between the first and second cavities; (b) the first cavity is configured to deliver breathing gas to both the patient's mouth and nostrils via the oral opening and the nasal opening, respectively; (c) the cushion module includes an exhaust vent for directing breathing gas from within the cushion module to an exterior of the cushion module; and (d) a cushion module, wherein the second cavity is in communication with the exhaust vent.

2. The cushion module of claim 1 , wherein the first cavity is a primary flow cavity and the second cavity is an exhaust cavity.

3. 3. The cushion module of claim 1 or 2, configured to accelerate breathing gas through the first cavity and into the nares.

4. The cushion module of any one of claims 1 to 3, wherein the first cavity is configured to accelerate breathing gas and direct the accelerated breathing gas toward the nasal openings.

5. The cushion module of claim 4 , wherein the first cavity is configured with a narrowing taper toward the nasal opening.

6. The cushion module of claim 5 , wherein the taper is formed between the cavity wall and a face-contacting wall portion disposed between the mouth opening and the nasal opening.

7. The cushion module of any one of claims 1 to 6, wherein the cavity wall includes a deformation region that deforms preferentially relative to the remainder of the cavity wall when a deformation force is applied to the cavity wall.

8. 8. The cushion module of claim 7, wherein the deformation region includes a deformation panel that is less resilient than the remainder of the deformation region, such that the deformation panel preferentially deforms when a deformation force is applied to a seal member.

9. 9. The cushion module of claim 8, wherein the deformation region further includes first and second elastic regions between which the deformation panel is disposed, the elastic regions directing deformation forces to the deformation panel to cause preferential deformation of the deformation panel.

10. 10. The cushion module of claim 9, wherein the deformation of the deformation region is accompanied by a decrease in the spacing between the first and second resilient regions and an associated deformation of the deformation panel to accommodate the decrease in spacing.

11. The cushioning module of any one of claims 8 to 10, wherein the deformation panel includes first and second walls adapted to deform in a predetermined sequence.

12. the predetermined sequence includes the deformation panel rolling on itself. Item 12. The cushion module according to item 11.

13. 13. The cushion module of claim 11 or 12, wherein the predetermined sequence includes the second wall rolling over the first wall.

14. 14. The cushion module of claim 11, wherein the first wall protrudes from the first elastic region in a first direction, the second wall protrudes from the second elastic region in a second direction different from the first direction, and the first wall intersects with the second wall, and the predetermined order includes the first wall being folded relative to the first elastic region.

15. The cushioning module of any one of claims 11 to 14, wherein the second wall is configured to induce rolling of the second wall over the first wall.

16. 16. The cushioning module of claim 15, wherein the second wall has a curved profile from the first wall to the second resilient region to induce a rolling motion in the second wall.

17. 17. The cushion module of claim 15 or 16, wherein the second wall increases in thickness from the first wall to the second elastic region to cause initial folding of the first wall during deformation and subsequent rolling of the second wall beginning at the intersection between the second wall and the first wall.

18. 18. A cushioning module as claimed in any one of claims 9 to 17, wherein the deformation panel has a wall thickness selected to induce deformation of the deformation panel in preference to the first and second resilient regions.

19. 20. The cushioning module of claim 18, wherein the first and second resilient regions have a wall thickness at least three times the wall thickness of the deforming panel.

20. The cushion module according to any one of claims 7 to 19, wherein the deformation region is a part of the cavity wall.

21. 21. The cushion module of claim 20, including a housing and a flexible seal member connected to a periphery of the housing, the seal member including the cavity wall.

22. 22. The cushion module of claim 21, wherein the cavity wall connects with the housing inside a connection between a periphery of the seal member and the periphery of the housing.

23. 23. The cushion module of claim 22, wherein the housing includes the exhaust vent.

24. 24. The cushion module of claim 23, wherein the cavity wall connection with the housing extends at least partially around the exhaust vent.

25. 25. The cushion module of claim 24, wherein the exhaust vent is bounded by the connection of the cavity wall with the housing and the connection between the perimeter of the seal and the perimeter of the housing.

26. 26. The cushion module of any one of claims 21 to 25, wherein the seal member is adapted to maintain a spaced apart relationship between the cavity wall and the nasal opening when a deforming force is applied to the seal member.

27. 27. The cushion module of claim 26, wherein the spaced apart relationship includes the cavity wall being recessed from the rim of the nasal opening.

28. 28. The cushion module of claim 27, wherein the spaced apart relationship further comprises the cavity walls being positioned such that the first and second cavities open to the nasal openings.

29. The cushion module of any one of claims 21 to 28, wherein the seal member is configured to direct at least a portion of a deformation force to the deformation region.

30. 30. The cushion module of claim 29, wherein the cavity wall is coupled to a face-contacting portion of the seal member to maintain the spaced apart relationship between the cavity wall and the nasal openings when a deforming force is applied to the seal member.

31. 31. The cushion module of claim 21, wherein the seal member includes a connecting member connecting the deformation region to a face-contacting portion of the seal member, whereby at least a portion of a deformation force applied to the face-contacting portion is directed to the deformation region.

32. 29. The cushion module of claim 21, wherein the cavity wall includes a deflector panel adjacent to the nasal opening, a main panel associated with the housing, and the deformation region between the deflector panel and the main panel.

33. 33. The cushion module of claim 32, wherein the deflector panel is recessed from the rim of the nasal opening, and a connecting member connects the face-contacting wall with the deflector panel to direct deformation forces to the deformation region.

34. 34. The cushion module of any one of claims 1 to 33, wherein an outlet from the first cavity to the nostril and an inlet to the second cavity form the nasal opening.

35. A cushion module as described in any one of claims 1 to 34, wherein the first cavity is a lower cavity and the second cavity is an upper cavity disposed above the first cavity.

36. A cushion module according to any preceding claim, wherein the nasal openings communicate with an outlet of the first cavity outlet and an inlet of the second cavity inlet.

37. A cavity wall for separating first and second cavities within a cushion module of a patient interface, the cavity wall having a deformation region adapted to preferentially deform under a deformation force applied to the cushion module.

38. 38. The cavity wall of claim 37, wherein the deformation region comprises a deformation panel that deforms under a deformation force.

39. The deformation region includes first and second elastic regions between which the deformation panel is disposed.

39. The cavity wall of claim 38, further comprising first and second resilient regions disposed therein, the resilient regions directing deformation forces to the deformation panel to cause preferential deformation of the deformation panel.

40. 40. The cavity wall of claim 39, wherein the deformation of the deformation region is accompanied by a decrease in the spacing between the first and second resilient regions and an associated deformation of the deformation panel to accommodate the decrease in spacing.

41. 41. The cavity wall of claim 40, wherein the deforming panel includes first and second walls adapted to deform in a predetermined sequence.

42. 42. The cavity wall of claim 41, wherein the first wall protrudes from the first elastic region in a first direction, the second wall protrudes from the second elastic region in a second direction different from the first direction, and the first and second walls have a connection therebetween, and the predetermined sequence includes the first wall being folded against the first elastic region.

43. 43. The cavity wall of claim 42, wherein the predetermined sequence includes buckling of the second wall to accommodate the reduction in spacing between the first and second resilient regions.

44. 44. The cavity wall of claim 43, wherein the second wall is configured to induce the buckling when a distance between the second resilient region and the connection is less than a length of the second wall.

45. 45. The cavity wall of claim 44, wherein the second wall has a curved profile from the connection to the second resilient region to induce buckling of the second wall.

46. 46. ​​The cavity wall of claim 44 or 45, wherein the second wall increases in thickness from the connection to the second elastic region to cause initial folding of the first wall and subsequent buckling in the second wall during deformation.

47. 47. A cavity wall according to any one of claims 40 to 46, wherein the deformation panel has a wall thickness selected to induce deformation of the deformation panel in preference to the first and second resilient regions.

48. 48. The cavity wall of claim 47, wherein the first and second resilient regions have a wall thickness that is at least three times the wall thickness of the deforming panel.

49. a non-invasive patient interface configured to deliver pressurized breathing gas to a patient's mouth and nares, the non-invasive patient interface comprising: a cushion module having first and second cavities with respective nasal and oral openings configured to deliver breathing gas to the patient's mouth and nares, respectively; (a) the first and second cavities are separated by a cavity wall that, in use, allows breathing gas to flow within the cushion module between the first and second cavities; and (b) the cavity wall is formed in accordance with any one of claims 37 to 48 and is configured to direct an external deformation force on the face-contacting portion of the cushion module to the deformation region such that the cavity wall deforms preferentially in the deformation region.

50. 50. A patient interface according to claim 49, wherein the first cavity is adapted to receive respiratory gas from a source and the second cavity is adapted to exhaust respiratory gas from within the cushion module.

51. 51. A patient interface according to claim 49 or 50, wherein the cavity wall is positioned relative to the nasal openings and oral openings to allow breathing gases to flow from the first cavity through the nasal openings to the nares.

52. 52. A patient interface according to any one of claims 49 to 51, wherein the cavity wall is positioned relative to the nasal and oral openings to allow exhaled breathing gases from the mouth and nostrils to flow into the second cavity.

53. A patient interface according to any one of claims 49 to 52, wherein the cavity walls are recessed relative to the rims of the nasal openings.

54. A patient interface according to any one of claims 48 to 53, wherein the cavity wall is positioned relative to the nasal openings such that the first and second cavities are in communication with the nasal openings.

55. 55. A patient interface according to claim 54, wherein an outlet of the first cavity and an inlet of the second cavity communicate with the nasal openings.

56. 56. A patient interface according to any one of claims 49 to 55, wherein the cushion module includes a connecting member extending from the face-contacting wall to the cavity wall, whereby at least a portion of the deformation force applied to the face-contacting wall is directed to the cavity wall.

57. 57. A patient interface according to claim 56, wherein the cavity wall is configured such that the connecting member directs a force applied to the face-contacting wall portion to the deformation region of the cavity wall.

58. 58. A patient interface according to claim 56 or 57, wherein the coupling member is connected to the cavity wall along a first connecting line.

59. A patient interface according to any one of claims 56 to 58, wherein the connecting members are recessed from the nasal openings.

60. 60. A patient interface according to any one of claims 56 to 59, wherein a face-contacting wall of the seal member is a first wall between the nasal openings and the mouth opening, whereby at least a portion of the force applied to the first wall is directed to the cavity wall.

61. 61. A patient interface according to claim 60, wherein the coupling member is connected to the first wall along a second connecting line.

62. 62. A patient interface according to claim 61, wherein the second connecting line comprises at least 10% of the distance of the first wall measured between the nasal openings and the oral opening outside the seal member.

63. The second connecting line is measured on the outside of the seal member between the nose opening and the mouth opening.

62. A patient interface according to claim 61, wherein the patient interface comprises at least 20% of the defined first wall distance.

64. 60. A patient interface according to any one of claims 49 to 59, wherein a face-contacting wall of the seal member is a second wall of the seal member located between the nasal openings and an exhaust vent, whereby force applied to the second wall is transferred to the cavity wall.

65. 65. A patient interface according to claim 64, wherein the coupling member is connected to the second wall along a third connecting line.

66. 66. A patient interface according to claim 61 or 65, wherein the second and / or third connecting lines terminate at the or each location spaced from the rim of the nasal opening.

67. 67. A patient interface according to claim 66, wherein the or each location is spaced from a bead surrounding a rim of the nasal opening.

68. A patient interface according to any one of claims 49 to 67, wherein the first cavity is a lower cavity configured to deliver breathing gas to both the mouth and the nostrils.

69. A patient interface according to any one of claims 49 to 68, wherein the cushion module further comprises an exhaust vent for directing breathing gas from within the cushion module to an exterior of the cushion module.

70. 70. A patient interface according to claim 69, wherein the second cavity is an upper cavity located above the first cavity and in communication with the exhaust vent.

71. 71. A patient interface according to claim 70, wherein the cushion module includes a housing and a seal member, and the cavity wall connects with the housing.

72. 72. A patient interface according to claim 71, wherein the housing includes the exhaust vent.

73. 73. A patient interface according to claim 71 or 72, wherein a cavity wall connection with the housing at least partially surrounds the exhaust vent.

74. 74. A patient interface according to any one of claims 71 to 73, wherein the exhaust vent is bounded by the connection of the cavity wall with the housing and the connection between the periphery of the seal and the periphery of the housing.

75. A patient interface according to any one of claims 71 to 74, wherein the cavity wall further comprises a main panel connecting the housing to the first resilient region.

76. 76. A patient interface according to claim 75, wherein the cavity walls further include deflector panels recessed from the rims of the nasal openings and forming channels for the flow of respiratory gases from the first cavity to the nasal openings.

77. 77. A patient interface according to claim 76, wherein the deflector panel abuts the second resilient region such that a deformation force is directed towards the second resilient region.

78. 78. A patient interface according to claim 76 or 77, wherein the deformation region is positioned to structurally decouple the deflector panel from the main panel.

79. 1. A non-invasive patient interface configured to deliver pressurized breathing gas to a patient's mouth and nostrils, comprising: (a) a seal for sealing around the mouth and nostrils of the patient; (b) a housing connected to the seal; (c) the internal volume claimed by the seal and the housing; a cushioning module including: (d) the seal includes a cavity wall disposed within the interior volume of the cushion module to define first and second cavities within the interior volume.

80. 80. A patient interface according to claim 79, wherein the cushion module further comprises a preferential deformation region comprising a deformation panel.

81. 81. A patient interface according to claim 80, wherein the deformation region further comprises first and second resilient regions between which the deformation panel is disposed.

82. 82. A patient interface according to claim 81, wherein deformation of the deformation region is accompanied by a decrease in spacing between the first and second resilient regions and an associated deformation of the deformation panel to accommodate the decrease in spacing.

83. 82. A patient interface according to claim 81, wherein the deforming panel includes first and second walls and a connection between the first and second walls.

84. 84. A patient interface according to claim 83, wherein the first wall protrudes from the first resilient region in a first direction and the second wall protrudes from the second resilient region in a second direction different from the first direction.

85. 85. A patient interface according to claim 84, wherein the second direction is sloped downwardly from a plane intersecting the second resilient region and the connecting portion.

86. 85. A patient interface according to claim 84, wherein the connecting portion, in a resting state, has a curved profile that is aligned with the first direction of the first wall and with an end of the second wall remote from the second elastic region.

87. 86. A patient interface according to claim 84 or 85, wherein the second wall has a curved profile from the connection portion to the second resilient region.

88. A patient interface according to any one of claims 84 to 86, wherein the second wall increases in thickness from the connection portion to the second resilient region.

89. A patient interface according to any one of claims 80 to 87, wherein the deforming panel has a wall thickness that is less than a wall thickness of the first and second resilient regions.

90. 90. A patient interface according to claim 88, wherein the first and second resilient regions have a wall thickness at least three times the wall thickness of the deforming panel.

91. A patient interface according to any one of claims 80 to 90, wherein the deformation region is part of the cavity wall.

92. 92. A patient interface according to claim 91, wherein the cavity wall further includes a main panel connecting the housing to the first resilient region.

93. 93. A patient interface according to claim 92, wherein the cavity walls further include deflector panels recessed from the rims of the nasal openings and forming channels configured to direct breathing gases from the first cavity to the nasal openings.

94. 94. A patient interface according to claim 93, wherein the deflector panel abuts the second resilient region.

95. 95. A patient interface according to claim 93 or 94, wherein the deformation region is positioned to structurally decouple the deflector panel from the main panel.

96. 96. A patient interface according to any one of claims 80 to 95, wherein the cavity wall is positioned relative to the nasal and oral openings to allow breathing gases to flow from the first cavity through the nasal openings to the nares.

97. 97. A patient interface according to any one of claims 80 to 96, wherein the cavity wall is positioned relative to the nasal and oral openings to allow exhaled breathing gases from the mouth and nostrils to flow into the second cavity.

98. A patient interface according to any one of claims 80 to 97, wherein the nasal openings are defined by a rim in the seal, and the cavity walls are recessed relative to the rim within the cushion module.

99. 99. A patient interface according to any one of claims 80 to 98, wherein the cavity walls are positioned relative to the nasal openings to enable the first and second cavities to deliver breathing gas to the nasal openings.

100. 100. A patient interface according to claim 99, wherein an outlet of the first cavity and an inlet of the second cavity communicate with the nasal openings.

101. 101. A patient interface according to any one of claims 80 to 100, wherein the cushion module further comprises: (a) a face-contacting wall of the seal; and (b) a connecting member extending from the face-contacting wall to the cavity wall.

102. 102. A patient interface according to claim 101, wherein the connecting member clamps the cavity wall in place against the nasal openings and the face-contacting wall.

103. 103. A patient interface according to claim 101 or 102, wherein the coupling member is connected to the cavity wall along a first connecting line.

104. A patient interface according to any one of claims 100 to 103, wherein the connecting members are recessed from the nasal openings.

105. A patient interface according to any one of claims 101 to 59, wherein the face-contacting wall is a first wall between the nasal openings and the mouth opening.

106. 106. A patient interface according to claim 105, wherein the coupling member is connected to the first wall along a second connecting line.

107. 107. A patient interface according to claim 106, wherein the second connecting line comprises at least 10% of the distance of the first wall measured between the nasal openings and the oral opening outside the seal member.

108. 107. A patient interface according to claim 106, wherein the second connecting line comprises at least 20% of the distance of the first wall measured between the nasal openings and the oral opening outside the seal member.

109. 60. A patient interface according to any one of claims 49 to 59, wherein the face contacting wall of the seal member is a second wall of the seal member located on an opposite side of the nasal openings from the face contacting wall.

110. 65. A patient interface according to claim 64, wherein the coupling member is connected to the second wall along a third connecting line.

111. 111. A patient interface according to claim 106 or 110, wherein the second and / or third connecting lines terminate at the or each location spaced from the rim of the nasal opening.

112. 112. A patient interface according to claim 111, wherein the or each location is spaced from a bead surrounding a rim of the nasal opening.

113. A patient interface according to any one of claims 80 to 112, wherein the first cavity is a lower cavity configured to deliver breathing gas to both the mouth and the nostrils.

114. A patient interface according to any one of claims 80 to 113, wherein the cushion module further comprises an exhaust vent for passing breathing gas from within the cushion module to an exterior of the cushion module.

115. 115. A patient interface according to claim 114, wherein the second cavity is an upper cavity disposed above the first cavity and in communication with the exhaust vent.

116. 116. A patient interface according to claim 115, wherein the housing includes the exhaust vent and the cavity wall connection with the housing at least partially surrounds the exhaust vent.

117. 117. A patient interface according to claim 116, wherein the exhaust vent is bounded by the connection of the cavity wall with the housing and the connection between the periphery of the seal and the periphery of the housing.

118. 118. A patient interface according to claim 117, wherein the exhaust vent comprises one or more groups of openings.

119. 1. A non-invasive patient interface having a seal-forming sealing member configured to cover a patient's mouth and nostrils, (a) a main flow cavity for separately delivering breathing gas to each of said mouth and said nostrils; And, (b) an exhaust flow cavity for directing exhaled air from the mouth and nostrils and excess breathing gas from the primary flow cavity, or both, to the exterior of the interface; the seal member includes a cavity wall separating the primary flow cavity from the exhaust flow cavity, and includes nasal openings that allow breathing gases to flow into and out of the nares, the cavity wall and the nasal openings being positioned to allow fresh breathing gases from the primary flow cavity to flow to the nares through the nasal openings, and to allow exhaled breathing gases from the nares, the primary flow cavity, or both, to flow to the exhaust cavity through the nasal openings.

120. A patient interface according to claim 119, wherein the cavity wall is formed in accordance with any one of claims 37 to 48.

121. 121. A patient interface according to claim 119 or 120, wherein the main flow cavity and the exhaust flow cavity are within a cushion module formed by the seal member and housing.

122. 122. A patient interface according to any one of claims 119 to 121, wherein the cavity walls are positioned relative to the nasal and oral openings of the primary flow cavity to allow breathing gas to flow from the primary flow cavity through the nasal openings to the nares.

123. 123. A patient interface according to claim 122, wherein the cavity walls are positioned relative to the nasal and oral openings to allow exhaled breathing gases from the mouth and nostrils to flow into the exhaust flow cavity.

124. A patient interface according to any one of claims 119 to 123, wherein the cavity walls are recessed relative to the rims of the nasal openings.

125. A patient interface according to any one of claims 119 to 124, wherein the cavity walls are positioned relative to the nasal openings such that the main flow cavity and the exhaust flow cavity communicate with the nasal openings.

126. 126. A patient interface according to claim 125, wherein an outlet of the main flow cavity and an inlet of the exhaust flow cavity communicate with the nasal openings.

127. A patient interface according to any one of claims 119 to 126, wherein the cushion module includes a connecting member extending from a face-contacting wall portion to the cavity wall, whereby at least a portion of a deformation force applied to the face-contacting wall portion is directed to the cavity wall.

128. 128. A patient interface according to claim 127, wherein the cavity wall is configured such that the connecting member directs a force applied to the face-contacting wall portion to the deformation region of the cavity wall.

129. 1. A method of delivering respiratory gas to a patient, comprising: delivering breathing gas at an elevated pressure to a first cavity within a cushion module of a patient interface to supply pressurized breathing gas from the first cavity to the patient's mouth and nares; accelerating a flow of breathing gas through a portion of the first cavity to deliver the accelerated flow of breathing gas to the nostril of the patient; A method comprising:

130. 130. The method of claim 129, further comprising venting breathing gas from a second cavity in the cushion module, the second cavity being in fluid communication with the first cavity.

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