Patient interface

Abstract

A cushion module for a patient interface is disclosed. The cushion module includes a first cavity, a second cavity, a nasal opening, and a mouth opening. The first and second cavities are separated by a cavity wall that allows breathing gas to flow between the first and second cavities within the cushion module during use. Furthermore, the first cavity is configured to deliver breathing gas to both the patient's mouth and nares via the mouth opening and the nasal opening, respectively. The cushion module includes an exhaust vent for delivering 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. A cavity wall and a cushion module are also disclosed.

Description

Technical Field

[0001] The present invention relates to a patient interface for delivering breathing gas to a patient. In particular, the present invention relates to a non-invasive patient interface.

Background Art

[0002] One of the current treatment methods for obstructive respiratory diseases such as chronic obstructive pulmonary disease (COPD - including emphysema, refractory asthma, chronic bronchitis) is non-invasive ventilation (NIV). This treatment method expands the airway by applying positive airway pressure to the lungs through the cycle of inhalation and exhalation. As a result, the flow of breathing gas in and out of the lungs is improved.

[0003] However, one of the side effects of the positive pressure applied in the current NIV treatment method is that the patient may feel discomfort and may not want to receive the treatment. The subsequent effect of the positive pressure is that, in order to prevent leakage and thus to ensure that the pressure is maintained reliably within the patient interface and the respiratory system, it is necessary to securely fix the patient interface to the patient. Fixing the interface securely in this way can cause pressure sores, especially in the case of semi-conscious or unconscious patients, and thus in patients who cannot provide feedback on the pain caused by the pressure of the patient interface on the skin.

[0004] The NIV treatment method has two problems: compliance (the degree to which the patient adheres to the treatment) and pressure sores. In addition to these problems, a further problem for patients with obstructive respiratory diseases is flushing carbon dioxide from the anatomical dead space. Specifically, the end of the exhalation cycle is characterized by a decrease in the pressure of the exhaled breathing gas. That is, the breathing gas containing carbon dioxide remains in the patient's throat, nose, and mouth and is drawn back into the lungs at the start of the inhalation cycle. The patient can be assisted by replacing the breathing gas containing carbon dioxide in these areas with breathing gas containing oxygen at a concentration suitable for the treatment of obstructive respiratory diseases.

Summary of the Invention

Problems to be Solved by the Invention

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

[0006] It is also desirable to provide a patient interface that aids in flushing anatomical dead space.

Means for Solving the Problems

[0007] Hereinafter, the present invention will be described by sets of embodiments, but the present invention may be exclusively defined by the features of each embodiment. However, it will also be understood that the present invention may be defined by two or more features of the embodiments.

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

[0009] The main flow path may include a main flow cavity having one or more main flow inlets for breathing gas and having one or more main flow outlets for delivering breathing gas to each of the mouth and nostrils.

[0010] The main flow path may include 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.

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

[0012] The interface may include a mask housing, and at least one of the one or more main flow inlets is within the housing.

[0013] The main flow cavity may be formed by a seal member and the housing.

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

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

[0016] The interface may include one or more of the 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 end of each passage.

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

[0019] The flushing flow outlet may be in the same plane as 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 nostril.

[0021] The flushing flow cavity may be shaped to direct respiratory gas into the nostril.

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

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

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

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

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

[0027] The seal member can be an elastic material and can be connected to the mask housing to form a unitary structure.

[0028] The seal member can be an elastic material and can be mechanically locked to the mask housing to form a unitary structure.

[0029] The seal member can be overmolded onto the mask housing to mechanically lock to the mask housing.

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

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

[0032] The mask frame may separately have a flow channel for delivering breathing gas to one or more main flow inlets and a flow channel for delivering breathing gas to one or more flushing flow inlets, and one or more flow channels for delivering breathing gas to 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 shaped portions on the mask housing and on the mask frame.

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

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

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

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

[0039] The seal member has one or more main flow outlets for guiding breathing gas into the nostrils and one or more flushing flow outlets for guiding breathing gas into the nostrils, and the main flow outlets and the flushing flow outlets can be arranged to collectively form the nasal opening.

[0040] The cavity wall can 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 can be a single passage from one or more flushing flow inlets to one or more flushing flow outlets.

[0042] The cavity wall of the flushing flow cavity can separate one or more flushing flow outlets from one or more main flow outlets for guiding breathing gas into the nostrils.

[0043] One or more flushing flow outlets can have a predetermined shape.

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

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

[0046] The tether can be substantially aligned with the septum of the patient during use.

[0047] The predetermined shape can be an hourglass shape, or a figure-eight shape, or a hippoped shape.

[0048] The predetermined shape can be an eight-shaped figure.

[0049] The exit ends of the tether and the cavity wall can be in the same plane as the main flow outlets for guiding breathing gas into the nostrils.

[0050] The tether can be recessed within the primary flow cavity to avoid contact with the patient when the interface is worn by the patient.

[0051] The cavity wall can be recessed within the primary flow cavity to avoid contact with the patient when the interface is worn by the patient.

[0052] The cavity wall can be recessed from the nasal aperture to avoid contact with the patient when the interface is worn by the patient.

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

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

[0055] The flushing flow channel can have internal dimensions that allow a lower volumetric flow rate of the breathing gas than the volumetric flow rate of the breathing gas allowed by the primary flow channel at the same temperature and pressure.

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

[0057] One or more primary flow inlets and one or more flushing flow inlets can be within the mask housing.

[0058] One or more main flow inlets may be within the mask housing, and one or more flushing flow inlets may be within the seal member.

[0059] The flushing flow path may include a flushing flow cavity having at least one outlet separate from the seal member such that the seal member and the outlet can move independently of each other.

[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 capable of flowing breathing gas from a gas source to the main flow inlet and a second breathing gas flow channel capable of flowing breathing gas 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, and the conduit has a distal end connected to the second breathing gas flow channel and a proximal end that terminates at or adjacent to the nasal opening.

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

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

[0064] The conduit may be formed of an elastic material.

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

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

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

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

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

[0070] One or more web members may extend from a position intermediate the proximal and distal ends of the conduit and connect to the seal member at a position 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] One or more web members may have a constant cross-section throughout their length.

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

[0074] The cross-section may be tapered outwardly from a 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 non-flexible structural region that supports the flexible region, and one or more web members are connected to the structural region.

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

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

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

[0079] The conduit and the second breathing gas flow channel may have cooperating shaped portions that enable the conduit to be fitted into the second breathing gas flow channel such that the flushing flow outlet is aligned to direct breathing gas to the patient's nostrils when the interface is worn by the patient.

[0080] The cooperating shaped portions 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 can be fitted into the second breathing gas flow channel, thereby ensuring proper placement of the conduit for directing breathing gas to the patient's nostrils when the interface is worn by the patient.

[0082] The shape of the groove may complement the shape of the flange.

[0083] The cooperating shaped portions may include a flange portion that at least partially extends around the outlet of the second breathing gas channel, a recess adjacent to and distal from the flange, and a flange receiving groove in the inner wall of the conduit that defines an inward lip, wherein the lip is latched into the recess when the flange portion seats in the groove, thereby ensuring proper alignment of the conduit for directing breathing gas to the patient's nostrils when the interface is worn by the patient.

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

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

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

[0087] One or more deformation zones may include bands.

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

[0089] The deformation zone may be formed on 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 seal member shaped to cover a patient's mouth and nostrils, the interface comprising (a) a main flow cavity for separately delivering breathing gas from a gas source to each of the mouth and nostrils, and (b) a flushing flow cavity for delivering breathing gas from a gas source to the nostrils defining, the main flow cavity and the flushing flow cavity being separated by a cavity wall that forms a partition between an inlet to the main flow cavity and an 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 each of the mouth and nostrils.

[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 separately delivering breathing gas 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 nostrils.

[0094] The interface may include a housing, and at least one of the one or more main flow inlets is within the housing.

[0095] The main flow cavity can be formed by a seal member and a housing.

[0096] The mask housing includes an opening defined by a cavity wall and defining a main flow inlet and a flushing flow inlet.

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

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

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

[0100] The seal member can have a first main flow outlet defined by a first portion of a mask seal that forms or substantially forms a seal surrounding 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 nostrils.

[0101] The flushing flow outlet can be in the same plane as the main flow outlet to the nostrils.

[0102] The seal member can be made of an elastic material and can be connected to the mask housing to form an integral structure.

[0103] The seal member can be made of an elastic material and can be mechanically locked to the mask housing to form a unitary structure.

[0104] The seal member can be overmolded onto the mask housing to mechanically lock to the mask housing.

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

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

[0107] The mask frame may have separate flow channels for delivering breathing gas to one or more main flow inlets and one or more flushing flow inlets, and one or more of the flow channels for delivering breathing gas to 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 shaped portions on the mask housing and on the mask frame.

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

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

[0112] The interface may include a vent hole for venting gas containing exhaled breath from the main flow cavity.

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

[0114] The interface may include an exhaust cavity through which exhaled breathing gas can be discharged to the outside of the interface.

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

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

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

[0118] 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 the wall of the exhaust cavity.

[0120] At least one exhaust gas inlet may be provided on the outer wall adjacent to one or more flushing flow outlets such that when the interface is worn by the patient, the nostrils overlap at least one exhaust gas inlet and one or more flushing flow outlets.

[0121] According to a third aspect, there is provided a non-invasive patient interface having a seal-forming seal member shaped to cover the patient's mouth and nostrils, the interface comprising (a) a main flow path for separately delivering breathing gas from a gas source to each of the mouth and nostrils, and (b) a flushing flow path for delivering breathing gas from the main flow path and / or the gas source to the nostrils defining, the main flow path includes a main flow cavity having a main flow inlet, the flushing flow path includes a flushing flow cavity having a flushing flow inlet, and the main flow inlet and the flushing flow inlet are formed by the seal member.

[0122] The main flow cavity may have one or more main flow outlets for delivering breathing gas to each of the mouth and nostrils.

[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 nostrils.

[0125] The interface may include a housing fixed to the seal member such that the main flow cavity is formed by the seal member and the housing.

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

[0127] One or more flushing flow outlets may be in the same plane as the main flow outlets to the nostrils.

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

[0129] The flushing flow cavity may be defined by a cavity wall that extends 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 the flushing flow cavity is defined by the cavity wall and the outer wall.

[0131] The flushing flow cavity may be configured to accelerate 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 surrounding 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 for the patient's nostrils.

[0133] The sealing member can be made of an elastic material and can be connected to the mask housing to form a unit structure.

[0134] The sealing member can be made of an elastic material and can be mechanically locked to the mask housing to form a unit structure.

[0135] The sealing member can be overmolded onto the mask housing to mechanically lock with the mask housing.

[0136] The interface can 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 can be removably connectable to the mask housing.

[0138] The mask frame can be removably connectable by cooperating snap-fit shaped portions on the mask housing and on the mask frame.

[0139] The mask frame can be removably connectable by cooperating shaped portions on the mask housing and on the mask frame.

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

[0141] The interface can include a vent hole for releasing gas including exhaled air from the main flow cavity.

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

[0143] The shapes of the main flow cavity and the flushing flow cavity can be selected to provide resistance to the gas flow that enables delivery of breathing gas through the main flow cavity to provide pressure support therapy and delivery of breathing gas through the flushing flow cavity to provide flushing of the anatomic dead space.

[0144] The seal member may include a nasal opening that is a combination of a flushing flow outlet and a main flow outlet that delivers breathing gas to the nostril, each of these two outlets provides 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 main flow outlet that delivers breathing gas to the nostril is selected to provide a desired resistance to the flow of breathing gas through the main flow cavity and the flow of breathing gas through the flushing flow cavity.

[0145] The cavity wall can be connected to the seal member such that its ratio does not substantially change when the interface is worn by the patient.

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

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

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

[0149] The main flow inlet and the flushing flow inlet can have a combined cross-sectional area that allows the 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 the seal member is molded to the mask housing.

[0150] According to a fourth aspect, there is provided a non-invasive patient interface having a seal-forming seal member shaped to cover a patient's mouth and nostrils, the interface comprising: (a) a main flow cavity having one or more main flow inlets for respiratory gas and one or more main flow outlets for delivering respiratory gas separately to each of the mouth and nostrils; (b) a flushing flow cavity having one or more flushing flow inlets for respiratory gas and one or more flushing flow outlets for delivering respiratory gas to the patient's nostrils; The main flow cavity and the flushing flow cavity are defined and separated by a cavity wall, the main flow outlet to the nostrils and the flushing flow outlet to the nostrils are adjacent to each other, and the cavity wall is arranged such that respiratory gas from the flushing flow cavity can enter the nostrils and exhaled gas can exit the nostrils and enter the main flow cavity.

[0151] The cavity wall includes one or more preferential deformation regions that accommodate deformation of the cavity wall without closing the flushing 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 respiratory gas and one or more main flow outlets for delivering respiratory gas separately to each of the mouth and nostrils; (b) a flushing flow cavity having one or more flushing flow inlets for respiratory gas and one or more flushing flow outlets for delivering respiratory gas to the patient's nostrils; The main flow cavity and the flushing flow cavity are defined and separated by a cavity wall, the cavity wall including one or more preferential deformation regions that accommodate deformation of the cavity wall without closing 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 can be disposed within the seal member.

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

[0155] The flushing flow outlet can be in the same plane as the main flow outlet to the nostril.

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

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

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

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

[0160] The seal member can have a first main flow outlet defined by a first portion of a mask seal that forms or substantially forms a seal surrounding the patient's mouth, and a second main flow outlet defined by a second portion of a mask seal that forms or substantially forms a seal for the patient's nostril.

[0161] The seal member can be an elastic material and can be connected to the mask housing to form a unitary structure.

[0162] The seal member can be an elastic material and can be mechanically locked to the mask housing to form a unitary structure.

[0163] The seal member can be overmolded on the mask housing to mechanically lock with the mask housing.

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

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

[0166] The cross-sectional area of the first inlet can be larger 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 resistance to the flow of the second breathing gas flow channel.

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

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

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

[0170] The mask frame can be removably connectable by cooperating snap-fit shaped portions on the mask housing and on the mask frame.

[0171] The mask frame can be removably connectable by cooperating shaped portions in the mask housing and the mask frame.

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

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

[0174] The mask seal has one or more main flow outlets for guiding breathing gas into the nostrils and one or more flushing flow outlets for guiding breathing gas into the nostrils, and the main flow outlets and the flushing flow outlets may be arranged side by side to form a nasal opening.

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

[0176] The cavity wall of the flushing flow cavity may separate one or more flushing flow outlets from one or more main flow outlets for guiding breathing gas into the nostrils.

[0177] One or more flushing flow outlets may have a predetermined shape.

[0178] The cavity wall may be connected to the rim of the nasal opening and include a tether for holding 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 septum of the patient when the mask is in use.

[0181] The seal member may be formed such that the cavity wall does not contact the patient.

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

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

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

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

[0186] The deformation region can be shaped to roll on one portion of the cavity wall when two portions of the cavity wall translate relative to each other.

[0187] The deformation region can have a wall thickness smaller than the wall thicknesses of the two portions so that the deformation region is more flexible than each of the two portions.

[0188] The cavity wall can 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 can each be shaped to resist deformation due to the force applied to the seal by engagement with the user's face.

[0190] The upper and lower cavity wall portions can be inclined relative to each other and are connected by a deformation region that allows relative shear movement between those portions.

[0191] The upper cavity wall portion can be an inclined valley shape with a side surface that curves upward, the lower cavity wall portion can be a curved wall with a side surface that curves outward and rearward, and the deformation region connects the upper cavity wall portion and the lower cavity wall portion.

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

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

[0194] The shapes of the upper cavity wall portion and the lower cavity wall portion may be selected such that when they deform, blockage of the primary flow cavity and the flushing flow cavity is avoided.

[0195] The tether may be recessed from the nose opening such that the tether does not contact the patient when the interface is worn by the patient.

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

[0197] The cavity wall is connected to the rim of the nose opening to define the cross-sectional areas of the flushing flow outlet and the primary flow outlet to the nostril and may resist changes in the cross-sectional areas of the flushing flow outlet and the primary flow outlet when the seal member deforms.

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

[0199] The seal member may include a bead surrounding the rim of the nose opening, the bead being less flexible than the surrounding seal member and thus having a wall thickness greater than the wall thickness of the surrounding seal member so as to resist closure of the nose opening.

[0200] The tether may be connected to the bead such that a deformation force is transmitted through the bead to the tether, one or both of the two cavity wall portions, and then to one or more preferential deformation regions.

[0201] The tether may contribute to resisting deformation of the nasal opening.

[0202] According to a sixth aspect, there is provided a non-invasive patient interface having a seal-forming seal member shaped to cover a patient's mouth and nostrils, the interface comprising: (a) a main flow cavity for individually delivering breathing gas to each of the mouth and nostrils; (b) an exhaust flow cavity for delivering exhaled breath from the mouth and nostrils and / or excess breathing gas from the main flow cavity to an external location of the interface; The seal member includes a cavity wall separating the main flow cavity from the exhaust flow cavity and includes a nasal opening enabling breathing gas to flow into and out of the nostrils, the cavity wall and the nasal opening being arranged such that breathing gas from the main flow cavity can flow through the nasal opening into the nostrils and exhaled breathing gas from the nostrils, the main flow cavity or both can flow through the nasal opening into the exhaust cavity.

[0203] The main flow cavity may have 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 a nasal opening and an oral opening enabling breathing gas to flow into and out of the mouth through the main flow cavity.

[0205] The interface may include an exhaust vent for delivering exhaled gas and excess breathing gas from the exhaust flow cavity to an external location of 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 includes one main flow inlet and one exhaust flow outlet, both of which are disposed within a seal member.

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

[0209] The exhaust flow inlet may be in the same plane as the main flow outlet to the nostrils.

[0210] The seal member may be an elastic material and may be connected to the mask housing to form an integral structure.

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

[0212] The seal member may be overmolded on the mask housing to mechanically lock 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 the 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 shaped portions on the mask housing and on the mask frame.

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

[0218] The seal member may have one or more second major flow outlets for directing breathing gas into the nostrils and one or more exhaust flow inlets for receiving gas flow from the nostrils and from the major flow cavity, the second major flow outlets and the exhaust flow inlets being adjacent to form the nasal opening.

[0219] The seal member may be formed such that the cavity wall does not contact 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 may be connected to the seal member adjacent to the rim by a tether recessed from the nasal opening to avoid contact with the patient.

[0222] The cavity wall may be recessed from the rim of the nasal opening to an extent that permits gas from the major flow cavity to flow into the exhaust flow cavity.

[0223] The cavity wall may be recessed from the rim of the nasal opening to an extent that permits gas from the major flow cavity to flow into the exhaust flow cavity when the patient interface is in use.

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

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

[0226] The deformation region can separate a 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 can separate one portion of the cavity wall from another portion of the cavity wall such that the two portions can move relative to each other.

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

[0229] The seal member can include a deformation resistance 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 seal member can include a bead that surrounds the rim of the nose opening, the bead having a wall thickness greater than the wall thickness of the surrounding seal member, whereby the bead is less flexible than the surrounding seal member and thus resists closure of the nose opening.

[0231] The tether can be connected to the bead such that a deformation force is transmitted through the bead to the tether, to one or both of the two cavity wall portions, and then to one or more preferred deformation regions.

[0232] The tether contributes to resisting deformation of the nose opening.

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

[0234] The mask frame can include a partition wall that can cooperate with the cavity wall to separate the main flow path from the exhaust flow path.

[0235] The mask frame can include a gas inlet on the opposite side or substantially opposite side of one or more first main flow outlets such that the main flow path is generally linear.

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

[0237] The mask frame may include a gas inlet that is disposed relative to the first major flow outlet such that the major flow path has a low resistance to the gas flow. The first major flow outlet may face the gas inlet so as to define a major 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 the cavity wall may be associated with the housing such that the exhaust cavity communicates with the exhaust vent.

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

[0241] The exhaust vent may include a series of openings that are grouped and arranged.

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

[0243] The cavity wall may contact the mask housing to form a seal that separates the exhaust cavity from the major flow cavity.

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

[0245] The mask housing may include a series of openings that can overmold the cavity wall to connect the cavity wall to the mask housing.

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

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

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

[0249] The seal member can be adapted to maintain a spaced relationship between the cavity wall and the nose opening when a deformation force is applied to the seal member.

[0250] The spaced relationship can be maintained by connecting the face contact portion of the seal member to the cavity wall.

[0251] The seal member can include a connecting member extending from the face contact wall portion of the seal member to the cavity wall, whereby at least a part of the deformation force applied to the face contact wall portion is induced to the cavity wall.

[0252] The face contact wall portion of the seal member can be the first wall portion between the nose opening and the mouth opening, whereby the force applied to the first wall portion is transmitted to the cavity wall.

[0253] The face contact wall portion of the seal member can be the second wall portion of the seal member located between the nose opening and the exhaust vent, whereby the force applied to the second wall portion is transmitted to the cavity wall.

[0254] The connecting member can be connected to the first wall portion along a connection line.

[0255] The connection line can include at least 10% of the distance of the first wall portion measured between the nose opening and the mouth opening outside the seal member.

[0256] The connection line can include at least 20% of the distance of the first wall portion measured between the nose opening and the mouth opening outside the seal member.

[0257] The connecting member can be connected to the second wall portion along the connection line.

[0258] The connecting member can be connected to the cavity wall along the connection line.

[0259] One or more connection lines can terminate at a position spaced from the rim of the nasal opening or at respective positions.

[0260] The position or respective positions can be spaced from the bead.

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

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

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

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

[0265] The deformation panel can have a thickness smaller than the thickness of the first and second elastic regions.

[0266] The deformation panel can include a first wall protruding from the first elastic region and a second wall connecting the first wall and the second elastic region.

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

[0268] The second wall can 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 increases in thickness from the first wall to the second elastic region, which can cause an initial bending of the first wall during deformation and subsequent rolling in the second wall starting from 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 connecting member can be connected to the second elastic region to guide the deformation force into the deformation region.

[0272] A hypothetical line extending from the intersection between the first elastic region and the first wall can converge at a pivot point with another hypothetical line extending along the intersection between the first wall and the second wall.

[0273] The first wall can protrude by a distance within the range of 1 to 10 mm from the first elastic region to the intersection with the second wall. The distance can be within the range of 2 to 5 mm. The distance can be 3 mm.

[0274] The second wall can protrude by a distance within the range of 2 to 15 mm from the second deformation resistance region. The distance can be within the range of 2 to 10 mm.

[0275] The first elastic region can constitute the first thickened region of the cavity wall.

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

[0277] The terminal panel can have a thickness at least twice that of the first wall. The terminal panel can have a thickness within the range of 0.5 to 3 mm.

[0278] The second elastic region can include a load diffusion member that joins to the side of the deformation region opposite to the side where the first elastic region joins.

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

[0280] The load diffusion member may be formed as a rib along one side of the deformation region and may be connected to the connecting member such that the force applied to the face contact wall portion of the sealing member is induced into the deformation region.

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

[0282] The second elastic region may be tapered to the same thickness as the surrounding cavity wall.

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

[0284] The cavity wall may be configured to allow breathing gas to flow from the main flow cavity to the nasal opening.

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

[0286] The connecting member may connect the face contact wall portion and the deflector panel to induce a force into the deformation region.

[0287] The deflector panel may abut against the second elastic region such that the force applied to the connecting member is transmitted to the second deformation resistance region.

[0288] The deflector panel may be connected to the inner wall of the sealing member away from the rim of the nasal opening.

[0289] The deflector panel may be connected to the inner wall of the sealing member away from a bead surrounding the rim of the nasal opening.

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

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

[0292] The socket insert may include a connection portion configured to connect the socket insert to an inlet on the housing and to connect to an outlet portion of the conduit connection 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 shape configured to interact with the shape of the socket insert to lock the frame against rotation relative to the housing when the frame and socket insert are combined with the housing.

[0296] The socket insert may include opposing shapes that can hold the frame and housing together therebetween.

[0297] The frame and housing may be held together by being compressed between the shapes of the socket insert when assembled.

[0298] The frame may include an opening configured to align with an exhaust vent of the mask housing and may allow for the discharge of breathing gas to the ambient environment through the frame.

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

[0300] The cavity wall can be formed according to a twelfth aspect.

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

[0302] The cavity wall can be arranged with respect to the nose opening and the mouth opening of the main flow cavity so as to allow breathing gas to flow from the main flow cavity through the nose opening into the nostrils.

[0303] The cavity wall can be arranged with respect to the nose opening and the mouth opening so as to allow exhaled breathing gas from the mouth and nostrils to flow into the exhaust flow cavity.

[0304] The cavity wall can be in a position recessed with respect to the rim of the nose opening.

[0305] The cavity wall can be arranged with respect to the nose opening such that the main flow cavity and the exhaust flow cavity communicate with the nose opening.

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

[0307] The cavity wall can be configured such that a force applied to the face contact wall portion by the connecting member is induced to the deformation region of the cavity wall.

[0308] The exhaust vents can 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 main flow inlet and includes a series of openings extending for each group.

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

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

[0312] According to a seventh aspect, there is provided a mask frame that forms a patient interface that can be pressurized in cooperation with a cushion module, the cushion module having a main flow cavity for delivering breathing gas to the patient's mouth and nostrils and an exhaust flow cavity for sending exhaled breathing gas from the patient interface, and the mask frame including a breathing gas inlet that is substantially aligned with the main flow outlet of the cushion module that delivers breathing gas to the patient's mouth.

[0313] The mask frame may include a partition wall that, in cooperation with the cushion module, defines separate main and exhaust flow paths through the assembled patient interface.

[0314] The mask frame may further include a vent hole for sending exhaled air from the exhaust cavity to the outside 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 breathing gas flow channels that allow breathing gas to flow from a gas source to a cushion module of the patient interface, (a) the breathing gas flowing from the first breathing gas flow channel to the second breathing gas flow channel, or (b) the breathing gas flowing from the second breathing gas flow channel to the first breathing gas flow channel, or (c) the breathing gas flowing from the first breathing gas flow channel to the second breathing gas flow channel and from the second breathing gas flow channel to the first breathing gas flow channel and including a flow switching valve that enables this.

[0316] The flow switching 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 can be the gas pressure in the first breathing gas flow channel or the second breathing gas flow channel when there is a complete or partial occlusion of the first breathing gas flow channel, the second breathing gas flow channel, the flushing flow cavity or the nasal opening.

[0318] The flow switching valve can include an opening sealed by an elastic cover, and the elasticity of the elastic cover is selected such that the elastic cover can be deformed by a gas pressure exceeding the threshold gas pressure so that breathing gas can pass through the opening when the gas pressure exceeds the threshold gas pressure.

[0319] The elastic cover can be a poppet valve.

[0320] The flow switching valve can be incorporated into a mask frame including at least the first and second breathing gas flow channels.

[0321] In an alternative form, the flow switching valve can be incorporated into a partition wall of the housing of the patient interface.

[0322] In a ninth aspect, a housing of a patient interface is provided that includes a lateral member having a lateral section that defines a space that is spaced apart and open to the outside on at least one side.

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

[0324] The housing can have a peripheral shaped portion that enables the fixing or connection of an elastic seal-forming seal member to form a cushion module incorporating the housing.

[0325] The peripheral shaped portion can include a series of holes dimensioned to enable the fixing or connection of an elastic 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 aspects disclosed above and an elastic seal-forming seal member that contacts the patient's face.

[0327] The elastic seal-forming seal member can be formed according to any of the aspects disclosed above.

[0328] An eleventh aspect is a cushion module for a patient interface, including a first cavity, a second cavity, a nose opening, and a mouth opening, a. The first and second cavities are separated by cavity walls that allow breathing gas to flow between the first and second cavities within the cushion module during use, b. The first cavity is configured to send breathing gas to both the patient's mouth and nostrils via the mouth opening and the nose opening, respectively, c. The cushion module includes an exhaust vent for sending breathing gas from within the cushion module to the outside of the cushion module, and d. The second cavity provides the cushion module in communication with the exhaust vent.

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

[0330] The cushion module can be configured to accelerate breathing gas into the nostrils through the first cavity.

[0331] The first cavity can be configured to accelerate breathing gas and direct the accelerated breathing gas towards the nose opening.

[0332] The first cavity can be configured to have a taper that narrows towards the nose opening.

[0333] The taper can be formed between the cavity wall and a face contact wall portion that can be disposed between the mouth opening and the nose opening.

[0334] The cavity wall includes a deformation region that preferentially deforms relative to the remaining portion 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 elastic than the remaining portion of the deformation region, such that the deformation panel preferentially deforms when a deformation force is applied to the sealing member.

[0336] The deformation region may further include first and second elastic regions between which the deformation panel is disposed, and the elastic regions may induce the 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 distance between the first and second elastic regions and a related deformation of the deformation panel to accommodate the decrease in the distance.

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

[0339] The predetermined order may include the deformation panel rolling on itself.

[0340] The predetermined order may include the second wall rolling on 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 intersects the second wall, and the predetermined order may include the first wall being bent with respect to the first elastic region.

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

[0343] The second wall may have a curved profile from the first wall to the second elastic region in order 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, causing an initial bend of the first wall during deformation and causing subsequent rolling of the second wall starting from the intersection between the second wall and the first wall.

[0345] The deformable panel may have a wall thickness selected to preferentially induce deformation of the deformable panel over the first and second elastic regions.

[0346] The first and second elastic 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 around the housing, and the seal member includes a cavity wall.

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

[0349] The housing may include an exhaust vent.

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

[0351] The exhaust vent may be bounded by the connection of the cavity wall to 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 relationship between the cavity wall and the nose opening when a deformation force is applied to the seal member.

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

[0354] The spaced relationship may further include that the cavity walls are arranged such that the first and second cavities open into the nasal opening.

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

[0356] When a deformation force is applied to the seal member, the cavity wall may be connected to the face contact portion of the seal member to maintain the spaced relationship between the cavity wall and the nasal opening.

[0357] The seal member may include a connecting member that connects the deformation region to the face contact portion of the seal member, whereby at least a portion of the deformation force applied to the face contact portion is directed into the deformation region.

[0358] The cavity wall may include a deflector panel adjacent to the nasal 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 the connecting member connects the face contact wall portion to the deflector panel to direct the deformation force into the deformation region.

[0360] The exit from the first cavity to the nostril and the entrance to the second cavity may form the 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 nasal opening may communicate with the exit of the first cavity outlet and the entrance of the second cavity entrance.

[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 guiding the deformation force to the deformation panel to cause preferential deformation of the deformation panel.

[0366] The deformation of the deformation region may involve a reduction in the spacing between the first and second elastic regions and a corresponding deformation of the deformation panel to accommodate the reduction in spacing.

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

[0368] 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 and second walls have a connection therebetween, the predetermined order may include the first wall being bent with respect to the first elastic region.

[0369] The predetermined order may include buckling of the second wall to accommodate a reduction in the spacing between the first and second elastic regions.

[0370] The second wall may be configured to induce buckling when the distance between the second elastic 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 elastic region to induce buckling of the second wall.

[0372] The second wall may increase in thickness from the connection portion to the second elastic region, causing an initial bending of the first wall during deformation and subsequent buckling in the second wall.

[0373] The deformable panel may have a wall thickness selected to induce deformation of the deformable panel preferentially over the first and second elastic regions.

[0374] The first and second elastic regions may have a wall thickness that is at least three times the wall thickness of the walls of the deformable panel.

[0375] A thirteenth aspect is a non-invasive patient interface configured to deliver pressurized breathing gas to a patient's mouth and nostrils, having a cushion module having first and second cavities each having a respective nose and mouth opening configured to send breathing gas to the patient's mouth and nostrils respectively, (a) the first and second cavities are separated by cavity walls that allow breathing gas to flow between the first and second cavities within the cushion module during use, and (b) the cavity walls are formed according to the twelfth aspect and are configured to direct an external deformation force on the face contact portion of the cushion module to a deformation region such that the cavity walls preferentially deform in the deformation region, providing a non-invasive patient interface.

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

[0377] The cavity walls may be arranged relative to the nose and mouth openings such that breathing gas can flow from the first cavity through the nose opening to the nostrils.

[0378] The cavity wall can be arranged relative to the nasal and oral openings such that exhaled respiratory gas from the mouth and nostrils can flow into the second cavity.

[0379] The cavity wall can be in a position recessed relative to the rim of the nasal opening.

[0380] The cavity wall can be arranged relative to the nasal opening such that the first and second cavities communicate with the nasal opening.

[0381] The outlet of the first cavity and the inlet of the second cavity can communicate with the nasal opening.

[0382] The cushion module can include a connecting member extending from the face contact wall portion to the cavity wall, whereby at least a part of the deformation force applied to the face contact wall portion is induced to the cavity wall.

[0383] The cavity wall can be configured such that the connecting member induces the force applied to the face contact wall portion to the deformation region of the cavity wall.

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

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

[0386] The face contact wall portion of the seal member can be the first wall portion between the nasal opening and the oral opening, whereby at least a part of the force applied to the first wall portion is induced to the cavity wall.

[0387] The connecting member can be connected to the first wall portion along a second connection line.

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

[0389] The second connection line includes at least 20% of the distance of the first wall portion measured between the nasal opening and the oral opening outside the sealing member.

[0390] The face contact wall portion of the sealing member can be the second wall portion of the sealing member located between the nasal opening and the exhaust vent, whereby the force applied to the second wall portion is transmitted to the cavity wall.

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

[0392] The second and / or third connection line may terminate at a position spaced from the rim of the nasal opening or at respective positions.

[0393] The position or respective positions may be spaced from a bead surrounding the rim of the nasal opening.

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

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

[0396] The second cavity is an upper cavity disposed above the first cavity and can communicate with the exhaust vent.

[0397] The cushion module may include a housing and a sealing member, and the cavity wall is connected to the housing.

[0398] The housing may include an exhaust vent.

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

[0400] The exhaust vent can be defined 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.

[0401] The cavity wall may further include a main panel that connects the housing to a first elastic region.

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

[0403] The deflector panel may abut against a second elastic region such that the deformation force is induced into the second elastic region.

[0404] The deformation region may be arranged to structurally separate 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, (a) a seal for sealing around the patient's mouth and nostrils, (b) a housing connected to the seal, (c) an internal volume defined by the seal and the housing including a cushion module, and (d) the seal includes a cavity wall disposed within the internal volume of the cushion module to define first and second cavities within the internal volume of the cushion module, providing a non-invasive patient interface.

[0406] The seal may further include a preferential deformation region including a deformable panel.

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

[0408] The deformation of the deformation region may involve a reduction in the distance between the first and second elastic regions and a related deformation of the deformation panel to accommodate the reduction in distance.

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

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

[0411] The second direction may be inclined downward from a plane intersecting the second elastic region and the connection.

[0412] In a stationary state, the connection may have a curved profile that aligns with the first direction of the first wall and with an end of the second wall that is remote from the second elastic region.

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

[0414] The second wall may increase in thickness from the connection to the second elastic region.

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

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

[0417] The cavity wall may further include a main panel that connects the housing to the first elastic region.

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

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

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

[0421] The cavity wall may be arranged relative to the nasal and oral openings such that breathing gas can flow from the first cavity through the nasal opening to the nostrils.

[0422] The cavity wall may be arranged relative to the nasal and oral openings such that exhaled breathing gas from the mouth and nostrils can flow into the second cavity.

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

[0424] The cavity wall may be arranged relative to the nasal opening such that the first and second cavities can direct breathing gas to the nasal opening.

[0425] The outlet of the first cavity and the inlet of the second cavity may communicate with the nasal opening.

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

[0427] The connecting member may clamp the cavity wall in place relative to the nasal opening and the face contact wall.

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

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

[0430] The face contact wall may be the first wall portion between the nasal opening and the oral opening.

[0431] The connecting member can be connected to the first wall portion along the second connection line.

[0432] The second connection line can include at least 10% of the distance of the first wall portion measured between the nasal opening and the oral opening outside the seal member.

[0433] The second connection line can include at least 20% of the distance of the first wall portion measured between the nasal opening and the oral opening outside the seal member.

[0434] The face contact wall portion of the seal member can be the second wall portion of the seal member located on the opposite side of the nasal opening with respect to the face contact wall portion.

[0435] The connecting member can be connected to the second wall portion along the third connection line.

[0436] The second and / or third connection lines can terminate at a position spaced apart from the rim of the nasal opening or at respective positions.

[0437] The position or respective positions can be spaced apart from a bead surrounding the rim of the nasal opening.

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

[0439] The cushion module can further include an exhaust vent for sending breathing gas from inside the cushion module to the outside of the cushion module.

[0440] The second cavity is an upper cavity disposed above the first cavity and can communicate with the exhaust vent.

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

[0442] The exhaust vent can be 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.

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

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

[0445] The first cavity can be configured to have a taper that narrows towards the nasal opening.

[0446] Any patient interface according to any aspect can be adapted to be connected to a flow generator to deliver breathing gas from the flow generator to the cushion module and transfer breathing gas from the cushion module to the flow generator.

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

[0448] The patient interface can include a coaxial conduit having an inner conduit and an outer conduit surrounding the inner conduit, and the inner conduit and the outer conduit define flow paths for breathing gas.

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

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

[0451] The mask frame may have an inner duct that connects an inner conduit to the main flow inlet of the cushion module to deliver breathing gas to the main flow cavity, and may also have an outer duct that surrounds the inner duct and connects an exhaust vent to the outer conduit.

[0452] The outer duct may include a connection shape configured to form a seal with the cushion module in a region overlapping the exhaust vent.

[0453] The connection shape may be a flange.

[0454] The cushion module may include an overmold where a 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 connect the inner conduit to the intake flow conduit of the flow generator and the outer conduit to the exhalation flow conduit of the flow generator.

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

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

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

[0461] The bias flow vent may be configured to impede connection to a conduit. For example, the bias flow vent may include one or more shaped portions that visually indicate that the respiratory system conduit should not be connected to the bias flow vent. Alternatively, the one or more shaped portions may inhibit a sealed connection with the respiratory system conduit to prevent occlusion of the bias flow vent.

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

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

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

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

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

[0467] The separate channels may branch at a location remote from an end of the frame on the cushion module side and become separate conduits.

[0468] The conduit associated with the inlet channel may be connectable to the intake flow conduit of the flow generator, and the conduit associated with the outlet channel may be connectable to the exhalation flow conduit of the flow generator.

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

[0470] The separate flow paths may include a composite opening at the end of the frame on the cushion module side, and a partition wall partitions the opening.

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

[0472] The partition wall may form a cross member that extends across the composite opening of a 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 fitting member that at least partially extends around a common opening and is configured to couple a single conduit to the cushion module.

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

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

[0476] The fitting member may partially include a sleeve that surrounds the opening of the frame, and this sleeve is configured to be coupled to the cushion module. The fitting member may further include an end of the single conduit that is adapted to be coupled to the sleeve.

[0477] The fitting member may include a friction fit portion or an interference fit portion or both for coupling the single conduit to the sleeve or the sleeve to the cushion module.

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

[0479] The first and second conduits may open into the cushion module at positions 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 to permit limited rotational movement of one or both of the conduits relative to the cushion module.

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

[0484] One or both of the conduits may include an elbow including a portion shaped as a spherical segment, adapted to couple with the cushion module, and further including 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 the mask frame in a fixed orientation, and the mask frame may provide respective respiratory gas flow paths between the cushion module and the first and second conduits.

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

[0488] According to a fifteenth aspect, a method of delivering respiratory gas to a patient, comprising (a) Delivering breathing gas at an elevated pressure into 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 nostrils; (b) Accelerating a breathing gas flow through a portion of the first cavity to deliver an accelerated breathing gas flow to the patient's nostrils A method is provided that includes the steps.

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

[0490] Although various features have been disclosed above in relation to one or more aspects, it will be understood that one or more features of one aspect may be combined with other aspects to achieve additional embodiments. It will be appreciated that the disclosure of a feature in the foregoing description is not to be construed as limited to the aspect in which it is disclosed. For example, a deformation region may be incorporated into a patient interface of any of the aspects described above. As another example, a flow switching valve may be incorporated into a patient interface of any of the aspects described above. As a further example, the patient interface housing disclosed above may be incorporated into a patient interface of any of the previous aspects. As a further example, the seal member disclosed above may be incorporated into a patient interface of any of the previous aspects.

[0491] Sequential references to aspects disclosed above (e.g., first, second, third, etc.) serve only to distinguish the aspects from one another. Sequential references are not to be construed as an indication of the order of importance of the aspects.

[0492] Aspects of the patient interface disclosed above are described in detail below with reference to embodiments that are illustrative only and with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0493]

Figure 1

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Figure 28B

Figure 29A-29B

Figure 29C-29D

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Figure 35B-35C

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Figure 42A-42B

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Figure 87

[0494] Here, preferred embodiments of the present invention will be described in the following text including reference numerals corresponding to the features shown in the accompanying drawings. Where possible, the same reference numerals are used to identify the same or substantially similar features in different embodiments. However, not all reference numerals are included in each figure in order to maintain the clarity of the figures.

[0495] The aspects of the patient interface disclosed above will be described in detail below with reference to an embodiment of the patient interface in the general form shown in FIG. 1. The embodiments described below are variations of that general form. However, the scope of those aspects should not be limited by reference to that general form or the specific embodiments described below. Instead, it will be understood that the aspects are related to other forms of patient interfaces that also deliver pressurized breathing gas to a patient, including a patient interface that extends across the bridge of the nose, a full-face mask, and a full-head helmet.

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

[0497] As used herein, the term "respiratory gas" is considered to mean a gas used in human respiration. As used herein, the term "inspiratory respiratory gas" is considered to mean a respiratory gas inhaled during the inspiratory phase of the respiratory cycle. This term includes within its scope air that has been adjusted for the treatment of a patient, such as ambient air or air with a higher humidity or oxygen level or both compared to ambient air. As used herein, the term "expiratory respiratory gas" is considered to mean a respiratory gas exhaled from a patient's lungs and airways. Thus, it includes the respiratory gas from the lungs, which occupies the anatomical dead space at the end of the expiratory phase of the respiratory cycle.

[0498] Referring to FIG. 1, a general form includes a patient interface 10 in the form of a nasal mask 10 that includes a cushion module 20 that includes an elastic seal member 12 and a housing 50, and the mask 10 further includes a mask frame 70 that connects to the cushion module 20. The cushion module 20 includes a nasal side portion and an oral side portion. A conduit from a gas source, such as a humidifier or a 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 delivering respiratory gas from the gas source to the cushion module 20 and thus to the patient. The mask frame 70 includes side wings 74 that extend from the central body portion 72. Each side wing 74 includes a pair of connectors in the form of bars 76 that are arranged to cooperate with a headgear (such as an elastic strap) to pull the mask 10 into contact with the patient's face to form a substantially airtight seal when high gas pressure respiratory gas is delivered to the patient via the mask 10.

[0500] Referring to the above description regarding the deformation modes of the general form shown in FIG. 1, one such deformation mode of the general form, which is applicable to the aspects and embodiments described hereinafter, is one in which the housing and the mask frame are integrally formed. In other words, the interface may include an integrated structure that performs the same functions as the housing and the mask frame described in the following aspects and embodiments. From this, in the following aspects and embodiments, although the housing and the mask frame are described as separate components of the patient interface, this description should be read as including the option of an integrally formed component that performs the same functions as the housing and the mask frame.

[0501] Embodiments of the mask 10 according to the first aspect are shown in FIGS. 2 to 5.

[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 is tapered from the inlet 78 to the outlet 86 such that the supply of breathing gas at a constant pressure is accelerated through the flushing flow channel 84 and a higher flow rate is obtained at the outlet 86 than at the inlet 78.

[0503] The mask frame 70 also includes a main flow channel 82 having a main flow channel inlet 80 and a main flow channel outlet 88. The outlet end of the main flow channel 82 is formed by a sleeve 90, which includes a groove-shaped portion 92 circumferentially disposed on the outer wall of the sleeve 90 for cooperation with a further sleeve 56 that defines an opening 54 of the housing 50. The sleeve 56 includes a snap-fit shaped portion on its radially inner wall that can cooperate with the snap-fit shaped portion 92 of the sleeve 90 to form a snap-fit connection therebetween. The cooperating snap-fit shaped portions 92 and 58 can provide a permanent connection between the mask frame 70 and the housing 50. Alternatively, the cooperating snap-fit shaped portions 92 and 58 can provide a releasable connection between the mask frame 70 and the housing 50, thereby enabling disassembly for replacement and cleaning of the components of the mask 10.

[0504] The housing 50 is formed of a substantially rigid plastic material and provides a chassis for supporting the cushion module 20 or adding structural support to the cushion module 20. The opening 54 has a size and shape for receiving the sleeve 90 of the mask frame 70. In the illustrated embodiment, the sleeve 56 and the sleeve 90 have corresponding non-circular profiles and cannot be attached to each other unless the mask frame 70 and the housing 50 are correctly aligned. In this way, the mask frame 70 is correctly positioned with respect to the housing 50 such that the flushing flow channel outlet 86 is received within the flushing flow cavity inlet 32 to enable communication of the breathing gas from the flushing flow channel 84 to the flushing flow cavity 28 provided in the seal member.

[0505] In an alternative embodiment, the sleeve 56 is configured to fit within the sleeve 90 of the mask frame 70. The sleeve 56 and the sleeve 90 also have corresponding non-circular profiles in this embodiment to ensure correct alignment of the mask frame 70 and the housing 50, after which they can be attached to each other.

[0506] The housing further includes two groups of vent openings 52 that are located below and slightly laterally of the opening 54. The vent openings 52 enable the exhaled breathing gas to be discharged to the outside of the mask 10. The housing in a further aspect includes a single set of vent openings 52.

[0507] As seen in the cross-sectional view of FIG. 5, the housing 50 includes a series of tab members 60 that project outwardly around it. The outer ends of the tab members 60 are connected to a bead 62 that extends continuously across all of the tab members 60, thereby forming a series of discrete windows immediately inside the perimeter of the housing 50. The seal member 12 is formed integrally with the housing by overmolding an elastic material onto the housing 50 so as to fill the series of windows. Thus, the tab members 60 and the bead 62 are embedded in the elastic material and mechanically interlocked with the seal member 12. Accordingly, the seal member 12 and the housing 50 form the structure of the integrated cushion module 20.

[0508] The seal member 12 is formed of a soft elastic material and includes a mouth opening 24 that encircles the patient's mouth when worn by the patient and a nose opening 26 that is located in the valley of the nose cradle 22 that is disposed to contact the underside of the patient's nose. The nose opening 24 is particularly arranged to align with the patient's nostrils when the mask 10 is worn by the patient, enabling pressure therapy to be performed through the nostrils. The seal member 12 further includes a flushing flow cavity 28. The flushing flow cavity 28 is formed integrally with the seal member 12. More specifically, the flushing flow cavity 28 is formed partially in the region of the nose cradle 22. In this particular embodiment, the flushing flow cavity is formed partially by the cavity wall 34 and partially by the wall of the seal member 12 in the region of the nose cradle 22.

[0509] In this embodiment, the cavity wall 34 is formed to have a single inlet 32 that communicates with the flushing flow channel outlet 86 of the mask frame 70 and provides a branched flushing flow cavity 28 having two flushing flow outlets 30 (FIG. 4). The flushing flow outlets 30 are in the same plane as the nose opening 26. Further, the flushing flow cavity 28 in the region directly upstream of the flushing flow outlets 30 turns upward to flow the breathing gas upward into the patient's nostrils (FIG. 5). Further, the flushing flow cavity 28 is tapered so that the cross-sectional area decreases along its length, further accelerating the flushing flow of the breathing gas from the inlet to the outlet end of the flushing flow cavity 28.

[0510] The seal member 12 and the housing 50 collectively define an internal volume that includes first and second cavities (referred to herein as the main flow cavity 36 and the flushing flow cavity 28, respectively). The breathing gas delivered through the main flow channel 82 flows into the main flow cavity 36, where it is inhaled by the patient through the mouth opening 24 and / or the nose opening 26. At the same time, the breathing gas is delivered to the flushing flow cavity 28 through the flushing flow channel 84 and then to the patient's nostrils through the flushing flow outlets 30.

[0511] During operation, the patient is provided with a sufficient amount of breathing gas through the main flow cavity 36 to meet its tidal volume requirement during the inhalation phase. At the same time, a stream of breathing gas that is a flushing flow is provided through the flushing flow cavity 28 and can contribute to the tidal volume of breathing gas required by the patient. The tidal volume flow rate is provided while maintaining a pressure above atmospheric pressure at the interface and in the patient's lungs. Nevertheless, the breathing gas provided through the main flow path is generally inhaled through the mouth via the mouth opening 24 or through the nose via the nasal opening 26 or sometimes both. During exhalation, the gas pressure of the exhaled breathing gas through the nostrils may exceed the gas pressure of the flushing flow. During this time, the exhaled breathing gas enters the main flow cavity 36 via either the mouth opening 24 or the nasal opening 26 and is exhausted to the outside of the mask via the vent opening 52. Without wishing to be bound by this theory, the applicant believes that when the gas pressure of the exhaled breathing gas through the nostrils decreases towards the end of the exhalation phase, the gas pressure of the flushing flow exceeds the gas pressure of the exhaled breathing gas through the nostrils at a certain point in the breathing cycle, and at that point, a flushing flow of fresh breathing gas begins to flow through the nostrils. The same is thought to be true when the patient breathes through the mouth and nose. However, when the patient breathes through the mouth only, flushing occurs throughout the exhalation cycle.

[0512] Although not desiring to be bound by this theory, Applicant believes that a faster flushing flow of breathing gas into the nostrils flushes exhaled breathing gas remaining in the patient's nasal cavity, throat and mouth at the end of the tapering expiratory air pressure breathing cycle. The nasal cavity, throat, and mouth can be collectively referred to as the patient's anatomical dead space. The flushing flow forces the exhaled breathing gas into the main flow cavity 636, where it is exhausted to the outside of the mask 10 through the vent opening 52. Applicant believes that such flushing increases the overall oxygen uptake during the next inhalation phase of the breathing cycle by reducing rebreathing of exhaled breathing gas. The increased oxygen uptake as a result of flushing the anatomical dead space is believed to improve the patient's breathing. In other words, the treatment described above is believed to facilitate and make more effective the breathing of patients suffering from obstructive respiratory diseases.

[0513] Also, Applicant believes that this dual cavity patient interface that accelerates one stream of breathing gas into the nostrils to cause flushing of the anatomical dead space allows the 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 breathing effectiveness resulting from reduced rebreathing of exhalation. This means that the patient can experience the same gas exchange even at relatively low therapy pressures. Operating at a gas pressure lower than the gas pressure used in existing NIV therapy may significantly improve the treatment effect of obstructive respiratory diseases because the lower gas pressure reduces compliance problems and the incidence of pressure ulcers. Alternatively, using the patient interface according to the embodiments disclosed herein, higher oxygen exchange can be enabled at the same NIV therapy pressure, thereby enabling better treatment of the patient.

[0514] In a variant of this embodiment, the flushing flow path inlet 78 and the main flow path inlet 80 can be combined into a single inlet of the mask frame 70. A partition 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. The advantage of this variant is that the patient interface 10 can be coupled to a single source of breathing gas, such as a ventilator, a flow generator, a wall source of pressurized air, or a CPAP device, that provides a single flow of breathing gas. A further advantage is that only a single conduit need be connected to the patient interface, thereby reducing the apparent size of the therapy system.

[0515] As used herein and in the claims, the term "flow generator" is considered to include flow generators, ventilators, CPAP devices, bi-PAP devices, VPAP devices, and wall sources of breathing gas.

[0516] Embodiments of the mask 110 according to the second aspect are shown in FIGS. 6-9. In those figures, features that are the same as or similar to the corresponding features in the first embodiment described above are denoted by like reference numerals preceded by the digit "1".

[0517] The mask 110 forms first and second cavities in the form of a main flow cavity 136 and a flushing flow cavity 128, respectively. The mask 110 differs from the mask 10 in that the flushing flow cavity 128 is formed as a single passage from a flushing flow cavity inlet 132 to a single flushing flow cavity outlet 130, instead of a branched flushing flow cavity. As shown in FIGS. 6 and 7, the outlet 130 is defined in part by a distal portion of the rim 138 and in part by a cavity wall 134 that terminates in the same plane as the nasal opening 126. The perimeter of the nasal opening 126 is formed in part by the cavity wall 134 and in part by a proximal portion of the rim 138. Together, the outlet 130 and the nasal opening 126 form a composite breathing gas opening that is disposed in the seal member 112 to align with the nostrils when the mask 10 is worn by the patient.

[0518] Similar to mask 10, the cavity wall 134 of mask 110 is shaped towards the outlet 30 such that breathing gas is directed upwards into the patient's nostrils. This is provided by the cavity wall 134 being inclined upwards towards the outlet 130 at a portion of the cavity wall 134 that is directly upstream of the outlet 130.

[0519] The distal portions of the cavity wall 134 and the rim 138 together provide the outlet 130 with a constricted waist shape such as a lemniscate, a hippoped, a figure-eight or an 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 in the same plane as the nasal opening 126. Further, its position means that it generally coincides with the nasal septum when the mask 110 is worn by the patient.

[0520] The tether 140 is integrally formed with the seal member 112 and thus comprises the same elastic material. It will be appreciated that the tether 140 reduces the extent to which the outlet 130 is occluded when the mask 110 deforms to fit the contour of the patient's face. In other words, the tether 140 reduces the extent to which the cavity wall 134 collapses towards the distal portion of the rim 138 and reduces the area of the outlet 130. It also reduces the extent to which the cavity wall 134 collapses towards the proximal portion of the rim 138 and reduces the area of the nasal opening 126. If either occurs, the effectiveness of the mask 110 in flushing the anatomical dead space and enabling inhalation from the nostrils will be reduced.

[0521] Also, the tether 140 counteracts the ballooning effect of the outlet 130 caused by an increase in the pressure of the breathing gas. The elevated gas pressure acts as a force that moves the cavity wall away from the rim 138 at the outlet 130, so that without the tether 140, the shape of the outlet would not be maintained. This means that the acceleration effect on the breathing gas generated 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 can be recessed within the flushing flow cavity 128 to avoid contact with the patient when the mask 110 is worn by the patient.

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

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

[0525] In a further alternative variant, the flushing flow cavity inlet 132 can be disposed within the housing 150 such that both the main flow channel 182 and the flushing flow channel 184 send breathing gas through the housing 152 to the respective main flow cavity 136 and flushing flow cavity 128. In each case, the channels 182 and 184 are connected in a sealed manner to the housing 150 and / or the seal member 120 such that pressurized breathing gas can flow through the channels 182 and 184 to the main flow cavity 136 and the flushing flow cavity 128.

[0526] In the embodiments of the first and second aspects as described above, one advantage obtained by integrating the flushing flow conduit and the flushing flow outlet with the seal member is that when the seal member deforms to fit the characteristics of the patient's face, for example when first worn or adjusted, the flushing flow cavity, and thus the flushing flow outlet, generally follows the deformation of the seal member. This means that the comfortable cushion module experience for the patient is maintained without interfering with the flushing effect of the anatomical dead space it provides. As described above, another advantage is that the flushing flow of the breathing gas is considered to increase the flushing of the nasal dead space and enhance the efficiency of treating patients suffering from obstructive respiratory diseases.

[0527] Embodiments of the mask 210 according to the third aspect are shown in FIGS. 10 - 13. In those figures, features that are the same as or similar to the corresponding features in the first embodiment described above are denoted by the same reference numerals preceded by the digit "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 within the housing 250. Specifically, the main flow channel delivers breathing gas to the lower part of the inlet 254 such that the breathing gas flows into the main flow cavity 236. The flushing flow channel delivers breathing gas to the upper part of the inlet 254 such that the breathing gas flows into the flushing flow cavity 228 (see FIG. 12).

[0529] Delivery of breathing gas through inlet 254 is enabled by cavity wall 234 extending across inlet 254 of the housing (Figs. 12 and 13). Thus, the flushing flow cavity inlet 232 is defined in part by the upper portion of inlet flange 256 and in part by the distal end of cavity wall 234. In Fig. 13, it can be seen that cavity wall 234 is inclined upwardly towards nose cradle 22 and terminates in the same plane as rim 238 of seal member 212 to form flushing flow outlet 230. Similar to mask 110, cavity wall 234 is shaped to form a volume that tapers inwardly towards flushing flow outlet 234, thereby accelerating breathing gas from inlet 232 to outlet 230.

[0530] The flushing flow outlet 230 has a shape of a lemniscate, figure eight or hippoped and is disposed directly adjacent to the outlet from the main flow cavity 236 to the nostril. The nose outlet 226 from the main flow cavity 236 and the flushing flow outlet together form a composite nose opening for delivering the main flow of breathing gas and the flushing flow of breathing gas to the nostril (Figs. 10 and 12).

[0531] Also, the mask 210 is different in that it includes an exhaust flow cavity 242 that is partially formed by an exhaust cavity wall 248 (separating the exhaust flow cavity 242 from the flushing flow cavity 228) and partially formed 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 when the mask 210 is worn on a patient, the nostrils overlap the inlet 244, the flushing flow outlet 230, and the nasal outlet 226. The exhaust flow cavity 242 also has an outlet 246 within the seal member 212, and the outlet 246 is distal to the patient. The inlet 244 receives the exhaled breathing gas from the nostrils and allows the exhaled breathing gas to move through the exhaust flow cavity 242 and out of the mask 210 via the outlet 246, thereby exhausting the exhaled breathing gas outside the mask. In a further aspect, the outlet 246 can be in the form of a plurality of vent openings. By having the exhaust outlet 246 close to the patient's nostrils, a path with low resistance for the exhaled air to be discharged from the patient's nostrils to the atmosphere is formed, which may improve the efficiency of dead space flushing.

[0532] In a variant of this embodiment, the inlet 244 can form part of the flushing flow path. For example, the inlet 244 can be incorporated into the rim 238 and can be formed in the exhaust cavity wall 248. FIG. 10 shows a mask 210 having three inlets 244, but in other variants of this embodiment, it will be understood that the mask 210 can have more or fewer inlets, provided that the exhaled breathing gas can enter the exhaust flow cavity 242. For example, one inlet 244 or two inlets 244 can be provided.

[0533] Embodiments of a mask 310 according to a fourth aspect are shown in FIGS. 14 - 18. In those figures, features that are the same as or similar to the corresponding features in the first embodiment described above are denoted by the same reference numerals preceded by the digit "3".

[0534] Similar to the mask 210, the mask 310 has a leading edge of a cavity wall 334 that partitions an opening 354 so as to divide an incoming flow of breathing gas between a first cavity and a second cavity (referred to herein as a main flow cavity 336 and a flushing flow cavity 328, respectively) (Figs. 14, 16, and 18). However, unlike the previous embodiments where the openings 54, 154, 254 are formed in the housing, it is important to understand that the opening 354 is formed in the seal member 312. The cavity wall 334 is inclined upwardly from the opening 354 (Figs. 14 and 16) and terminates at a position in front of a composite nose opening formed by a flushing flow outlet 330 and a nose outlet 326 from the main flow cavity 336 (Figs. 15 and 18). This means that the flushing flow outlet 330 is formed partly by an upper rim of the cavity wall 334 and partly by a rim 338. However, the cavity wall 334 is connected to the wall of the cushion member at the rim 338 (Fig. 15). By connecting the cavity wall 334 with the rim 338, it is ensured that the cavity wall 334 moves together with the rim 338 when the seal member 312 is adjusted, and thus the sizes of the nose outlet 326 and the flushing flow outlet 330 are substantially maintained despite the adjustment of the mask 310 such that the contour of the seal member 312 changes to fit the patient. Also, this connection has the advantage of improving the structural stability of the seal member 312, thereby reducing the risk of occluding the nose outlet 326 and the flushing flow outlet 330. Despite the similarity to the cavity wall 210 of the previous embodiments, the upper rim of the cavity wall 334 is recessed from the composite nose opening and thus is not at the same height as the nose opening. However, similar to the previous embodiments, the cavity wall 334 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 in combination with the outer wall of the seal member 312.

[0535] By recessing the upper rim of the cavity wall 334 from the composite nasal opening, contact with the patient's septum can be avoided, thus avoiding irritation and improving patient comfort. Further, the space between the upper rim and the nostril forms an anterior chamber, and since there is a space for the gas to flow in when the gas exits the nostril, it allows for a smoother gas flow. In contrast, when the rim 338 of the composite nasal opening contacts the nostril, the exhaled breathing gas from the nostril will be split between the flushing flow cavity 328 and the main flow cavity 336 by the rim 338. During exhalation from the nose, for example, the addition of the anterior chamber formed by the recessed upper rim of the cavity wall 334 means that the exhaled breathing gas will enter the anterior chamber and then flow into the main flow cavity 336 without some of the breathing gas being split and sent to the flushing flow cavity 328.

[0536] Similar to the other masks described above, the mask 310 has a main flow cavity 336 that operates to deliver breathing gas to the patient via the mouth opening 324 and the nasal outlet 326 (as indicated by the arrows showing the flow of breathing gas to the mouth opening 324 and the nasal outlet 326 in FIG. 18). The nasal outlet 326 is formed between the rim 338 and the cavity wall 334 proximal to the seal member 312.

[0537] In contrast to the mask described above, the mask frame 370 has the same cheek flanges 374 and connector bar 376, but includes only a main flow channel 382 for delivering breathing gas from a gas source to the opening 354. In view of the single flow channel of the mask frame 370, the flushing flow channel is not incorporated into the mask frame 370. This is because the flow of breathing gas that flows into the flushing flow cavity 328 is delivered by the main flow channel 382. The single flow channel simplifies the connection between the mask 310 and the mask frame 370 and the cushion module 320, and is thus beneficial by reducing any risks associated with, for example, correctly setting up the mask 310.

[0538] In a single flow channel that delivers breathing gas to the primary flow channel 382 and the flushing flow channel 384, it will be understood that the resistance to flow in each of the flushing flow cavity 328 and the primary flow cavity 336 is extremely important to ensure proper delivery of the breathing gas at the pressures and velocities required to achieve the desired treatment. In other words, the ratio of the resistance to flow through the flushing flow cavity 328 and the primary flow cavity 336 determines the split of the breathing gas flow between the two cavities. As a result, the flow can be set by designing cavities that have the necessary relative resistance to flow in each cavity. For the flushing flow outlet 330 and the nasal outlet 326, the resistance to flow can be adjusted by changing the cross-sectional areas of the flushing flow outlet 330 and the nasal outlet 326. A low flow resistance is also made possible by a low angle change in the direction of the breathing gas flow through the cushion module 320 (typically in the range of 0 to 20°).

[0539] A significant difference between mask 310 and the masks of the previous embodiments is that, as shown in FIGS. 19A and 19B, it includes a housing 350 having a lateral member with a lateral section that defines a spaced-apart interval opening outward on at least one side. As shown in FIGS. 19A and 19B, housing 350 generally has a U-shaped form, but alternatively may have an inverted U-shaped, V-shaped or H-shaped form. Similar to the previous embodiments, the peripheral portion of housing 350 includes a peripheral shaped portion that enables the fixing of an elastic seal member to form a cushion module incorporating the housing. The peripheral shaped portion includes a series of holes sized to enable the fixing of elastic seal member 312 by overmolding. In this embodiment, the peripheral shaped portion includes a series of outwardly extending tab members 360, and these tab members 360 support a continuous bead 362 that forms the perimeter of housing 350 at their outer ends. Tabs 360 and bead 362 form a series of window-shaped holes, and seal member 312 is overmolded to cover them, forming a permanent connection, i.e., an interlock, between housing 350 and seal member 312.

[0540] The U-shaped configuration of housing 350 enables the opening 354 to be formed much larger than in other embodiments (FIGS. 14 and 16). This means that the transfer of breathing gas from mask frame 370 to flushing flow cavity 328 and primary flow cavity 336 is smoother, thus potentially reducing an undesirable amount of turbulent flow, while also meaning that the resistance to flow through both is reduced. The low flow resistance is important for achieving the correct ratio of breathing gas flow between flushing flow cavity 328 and primary flow cavity 336. The larger opening 354 also enables a larger mold tool core to be removed from opening 354 when overmolding seal member 312 onto housing 350, which is important, for example, when designing complex multi-cavity silicone parts. This significantly improves the flexibility of the cavity shape that can be formed within the cushion module to control the breathing gas flow.

[0541] An embodiment of the mask 410 according to a modified form of the first aspect is shown in FIGS. 20 to 24. In those figures, features identical or similar to the corresponding features in the above-described first embodiment are denoted by the same reference numerals preceded by the digit "4".

[0542] A cross-section of the mask 410 is shown in FIG. 20A, and a front view and a side view 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, but the seal member 412 is different in that the cavity wall 434 is formed as a conduit in the form of a tube in this embodiment, which defines a flushing flow cavity 428 and is surrounded by the main flow cavity 436. The main flow cavity 536 and the flushing flow cavity 428 define the first and second cavities, respectively. The 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 nose cradle 422. In other words, the flushing flow outlet 430 is movable independently of the seal member 412 and also of the nose outlet 426. This can provide a more comfortable mask, or in other words a mask that can accommodate a wider range of face shapes, due to decoupling the movement between the nose opening 426 and the flushing flow outlet 430. This decoupling is more clearly shown in FIGS. 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 to the seal member 412 at its distal end, where the seal member 412 is overmolded onto the housing 50 (FIGS. 20A and 21).

[0544] The mask frame 470 includes two main flow channels 482 (see FIG. 21, a front plan view of the mask 410 shown in FIG. 21, in conjunction with FIG. 1, where one main flow channel is associated with each inlet 480), and a single flushing flow channel 484. Both main flow channels 482 deliver breathing gas to the main flow cavity 436, and the single flushing flow channel 484 delivers breathing gas to the flushing flow cavity 428. It should be understood, of course, that the mask frame may have only a single main flow channel. FIG. 21 shows the flow of breathing gas through the mask frame 470 and the cushion module 420, but this figure is schematic and does not show one of the two main flow channels 482. Instead, one of the main flow channels 482 may be used for sampling the mask pressure and the other for delivery of pressurized gas. Further, in additional embodiments, one of the main flow channels 482 may be used to deliver a mixed gas different from the supplemental oxygen or the other main flow channel 482 delivers. FIG. 21 shows a single arrow indicating that breathing gas flows through the main flow channel 482 when it enters the main flow cavity 36, but it will be understood that the breathing gas is then delivered to the patient via the mouth opening 424, the nose outlet 426, or both.

[0545] Further, it will be understood that the mask 410 operates in the same manner as the mask 10 to treat obstructive respiratory diseases by flushing the anatomical dead space and by applying an air pressure elevated above the ambient air pressure to the patient's respiratory system.

[0546] By disconnecting the flushing flow outlet 430 from the nose cradle 422, it is possible to avoid forming a connection portion with a greater thickness of material between the two regions than in other regions. The thicker regions are less flexible and thus less adaptable to the shape of the face. That is, these stiff regions can cause pressure indentations or patient pain when the mask 410 is worn for an extended period of time. Disconnecting the flushing flow outlet 430 from the nose cradle 422 may improve patient comfort, but the flushing flow outlet 430 does not follow the movement of the nose outlet 426 very well. The variant forms shown in FIGS. 22 and 24 provide options that allow for follow-up (for the purpose of providing effective treatment) and allow for comfort that reduces the potential for patient pain and pressure indentations.

[0547] FIG. 22 shows four options for support links between the flushing flow cavity 428 and the cushion module 420: - FIG. 22A shows a web 402 that is above the flushing flow cavity 428 and extends distally from the rim 438 and the flushing flow outlet 430. - FIG. 22B shows a partition wall 404 that is above the flushing flow cavity 428, extends distally from the rim 438 and the flushing flow outlet 30, and extends along the entire length of the flushing flow cavity 428. - FIG. 22C shows a single rib or tie 406 that connects the flushing flow cavity 428 to the nose cradle 422, and this rib or tie 406 is located above the flushing flow cavity 428 and is spaced distally from the rim 438 and the flushing flow outlet 430. - FIG. 22D shows two separate tethers 408 that extend in the opposite direction from the flushing flow outlet 430 towards the rim 438 and connect to the rim 438.

[0548] FIG. 24 shows exemplary configurations of four different tethers 408 that can be used instead of or in combination with the support links shown in FIGS. 22A - 22D. The tethers 408 provide support in the lateral, vertical, or both lateral and vertical directions to the flushing flow cavity 428. In particular, - FIG. 24A shows a tether 408a extending from the reinforced shoulder 96 of the cushion module 420 to the upper corner of the flushing flow cavity 428. The tether 408a is tapered outwardly from its midpoint to its ends. - FIG. 24B shows a tether 408b extending from the side rib portion 98 of the cushion module 420 to the upper corner of the flushing flow cavity 428. The tethers 408b are tapered outwardly from their midpoints to their ends. - FIG. 24C shows a tether 408c extending from a position adjacent to the bottom valley of the nose cradle 422 to the upper corner of the flushing flow cavity 428. The tether 408c has a constant cross - section over its entire length. - FIG. 24D shows a short tether 408d extending from the midpoint above the flushing flow cavity 428 to the bottom valley of the nasal cavity 422. The tether 408d is tapered outwardly towards its ends.

[0549] From the above options regarding the configuration of the support links and tethers 408, it will be understood that the mask 410 may include one or more web members (such as support links, tethers, or both) that couple the flushing flow cavity 428 to the seal member 412 such that, for example, when the cushion module deforms upon wearing the mask 410 on a patient, the flushing flow outlet 430 follows the nasal outlet 426. In other words, the support links and tethers enable the flushing flow cavity 428 to follow the nasal outlet 426 for different face shapes. However, it is important to understand that the position and shape of the web members (such as support links, tethers, or both) are selected to substantially retain the flexibility of the cushion module without the web members and to avoid regions of undesired increased thickness that could lead to patient discomfort.

[0550] Tracking 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 donning or adjustment, the one or more web members apply a force to the flushing flow cavity 428.

[0551] Figures 24A and 24B show one option for enabling tracking without increasing the stiffness of the region of the seal member 412 that contacts the patient. These figures show tethers 408a and 408b that connect to portions of the reinforced shoulders 496 and side ribs 498 of the cushion module. The selection of these tether points results from the cushion module 420 including a flexible region that adapts to the shape of the patient's face and a relatively inflexible structural region that supports that flexible region. The structural regions, namely the shoulders 496 and side ribs 498, include a portion of the cushion module 420 that is attached to the housing 450 via overmolding in these deformation configurations. That is, the portion of the cushion module 420 in which the tab members 460 and beads 462 are embedded. However, it will be understood that other structural regions can be used as attachment points for tethers and support links.

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

[0553] Embodiments of the mask 510 according to a further variation of the first aspect are shown in FIGS. 24 - 29.

[0554] The seal member 512 is formed of a soft and elastic material and includes an oral opening 524 that encircles the patient's mouth when worn by the patient, and also includes a nasal opening 526 that is located in the groove of the nose cradle 522. The nasal opening 526 is arranged to be aligned with the patient's nostrils, particularly when the mask 510 is worn by the patient. An opening 554 for sending breathing gas into or through the cushion module 520 is formed in the cushion module 520 on the side opposite the oral opening 524. The seal member 512 is permanently fixed to a housing 550 that has the same form as the housing 450 described above and shown in FIGS. 19A and 19B. The cushion module 520 defines a main flow cavity 536 (i.e., the first cavity), and breathing gas is sent through this cavity to the oral opening 524 and the nasal opening 526.

[0555] The mask 510 further includes a mask frame 570, the mask frame 570 has side wings 574 and a connector bar 576, and has a single main flow path inlet 580 for sending breathing gas to a downstream main flow channel outlet 588, and this main flow channel outlet 588 delivers breathing gas into the main flow cavity 536 through the opening 554. As shown in FIGS. 26 and 27, the mask 510 also has a flushing flow channel 584 downstream of the main flow path inlet 580 for sending breathing gas through a flushing flow path inlet 578 to the flushing flow channel 584 and then to a flushing flow cavity 528 (i.e., the second cavity). The flushing flow channel 584 is formed as a tube that extends proximally away from the body 572 of the mask frame 570. When the mask frame 570 is attached to the cushion module 520, the flushing flow channel 584 projects in a direction towards the nasal opening 526 inside the cushion module 520.

[0556] The flushing flow cavity 528 (see FIGS. 26 and 27) is formed separately from the mask frame 570 and the cushion module 520 and is connected to the mask frame 570 at the flushing flow channel outlet 586. The flushing flow cavity 528 is formed of a soft, compliant, elastic material so that the relatively thin-walled outlet 530 can be easily deformed to adapt to different face shapes. In contrast, the inlet 532 has a thicker wall and is thus less flexible, forming a strong connection with the mask frame 570 so that the flushing flow cavity 528 is not separated from the flushing flow channel 584 by the deformation of the outlet 530. The flushing flow channel 584 generally has an overall substantially uniform cross-section, but the flushing flow cavity 528 defines a passage that is tapered inwardly from its inlet 532 to its outlet 530 to accelerate the breathing gas and direct the breathing gas into the patient's nostrils.

[0557] The flushing flow cavity 528 and the flushing flow channel 584 have cooperating shaped parts (FIGS. 27 and 28), such as snap-fit shaped parts, that allow the flushing flow cavity 528 to be fitted into the flushing flow channel 584 such that the outlet 530 is in the same plane as the nasal opening 526 or slightly recessed from the nasal opening 526 (FIG. 27). According to this embodiment, the cooperating shaped part on the flushing flow channel 584 includes 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 28 has a flange receiving groove 542 adjacent to 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 shaped portion can include a keyed fitting of the flushing flow channel 584 and an inlet end to the flushing flow cavity 528 dimensioned closely to the keyed fitting such that the inlet end must be elastically deformed to receive the keyed fitting. In another variation, the inlet end of the flushing flow cavity 528 can be overmolded around a rigid connecting member, such as a ring, that snap fits with the cooperable shaped portion on the flushing flow channel 584. A range of alternative cooperable shaped portions can be used between the flushing flow cavity 528 and the flushing flow channel 584 so long as they provide a substantially airtight connection upon an increase in gas pressure.

[0559] The shapes of the groove 542 and the flange 540 can take any suitable form that provides a secure connection. In this embodiment, the groove 542 is formed by a limiting wall 544 that abuts an end wall 546 of the flushing flow channel 584 to limit the extent to which the flushing flow cavity 528 can be fitted into the flushing flow channel 584. Thereby, the limiting wall 544 ensures proper placement of the flushing flow cavity 528 to direct breathing gas to the patient's nostrils when the interface is worn by the patient.

[0560] The cooperable shaped portion further includes 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 gas to the patient's nostrils when the mask 510 is worn by the patient.

[0561] To assist in reducing resistance to the flow of breathing gas, the inner wall of the flushing flow channel 584 is coplanar with the inner wall of the flushing flow cavity 528 at the point where the flushing flow cavity 528 connects to the flushing flow channel 584.

[0562] In a variant of this embodiment, the profile of the flushing flow cavity 528 includes one or more preferential deformation zones in the form of a band 508 with a reduced wall thickness (as shown in FIGS. 29A - 29D) or in the form of a region with a reduced thickness in an alternative embodiment, at a location away from the outlet 530, in order to allow the flushing flow cavity 528 to follow the movement of the nose opening 526 while substantially maintaining the shape of the flushing flow outlet 530. Placing the band 508 close to the inlet end of the flushing flow cavity 528 means that deformation occurs in a region where the cross - sectional area of the flushing flow cavity 528 is larger compared to a downstream region where the taper of the flushing flow cavity 528 has a smaller cross - sectional area. Thus, the band 508 reduces the possibility of the flushing flow cavity 528 becoming blocked when it deforms to follow the nose opening 526.

[0563] The variants shown in FIGS. 29A and 29B show a flushing flow cavity 528 having 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 the adjacent region. Another variant shown in FIGS. 29C and 29D includes two bands 508. The bands 508 have a curved profile, but it will be understood that the bands 508 can have other profiles that allow preferential deformation at the location of the bands. For example, an alternative profile is a square profile. The location of the bands 508 outside the flushing flow cavity 528 ensures that the inner wall 506 remains smooth and thus provides a low - flow - resistance flow path through the flushing flow cavity.

[0564] Embodiments of the mask 610 according to the seventh and eighth aspects are shown in FIGS. 30 - 42.

[0565] The mask 610 includes a seal member 612 that is permanently fixed to a housing 650 (of the same form as the housing shown in FIGS. 19A and 19B) by overmolding to form a cushion module 620. The seal member 612 is formed of a soft and elastic material such as silicone and includes a mouth opening 624 that encircles the patient's mouth when worn by the patient, and composite nose openings 626, 630 that are located in the valleys of the nose cradle 622. The composite nose openings include a main flow outlet 626 and a flushing flow outlet 630 that are arranged adjacent to each other. A cavity wall 634 is formed inside the seal member 620 to define first and second cavities, namely a main flow cavity 636 and a flushing flow cavity 628, respectively. The flushing flow cavity 628 is formed in the upper part of the seal member 620, and the main flow cavity 636 is formed in the remaining part of the seal member 620 in combination with the housing 650. The nose outlet 626 is arranged to fit the patient's nostrils, especially when the mask 610 is worn by the patient. Further, the cavity wall 634 is arranged to allow the breathing gas from the flushing flow cavity 628 to enter the nostrils and the exhaled gas to exit from the nostrils to the main flow cavity 636. Further, the cavity wall 634 is arranged to allow the excess breathing gas from the flushing flow cavity 628 to pass between the cavity wall and the patient's face and enter the main flow cavity 636 and be exhausted to the atmosphere from the exhaust vent of the main flow cavity 636.

[0566] An opening 654 for sending breathing gas into or through the cushion module 620 is formed in the seal member 612 on the opposite side of the mouth opening 624. Together, the seal member 612 and the housing 650 define a main flow cavity 636 through which the breathing gas is sent to the mouth opening 624 and the nose outlet 626.

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

[0568] The mask 610 further includes a mask frame 670 (see FIGS. 36 - 41), the mask frame 670 having side wings 674 and a connector bar 676, and having a single main flow path inlet 680 for sending breathing gas to a downstream main flow channel outlet 688 that delivers breathing gas into the main flow cavity 636 through the opening 654. The mask 610 also has a flushing flow channel 684 downstream of the main flow path inlet 680 for sending breathing gas through the flushing flow path 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 blocking 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 the flushing flow cavity 628 being blocked. 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 the opening 654 and partitions it to form a flushing flow cavity inlet 632 and an inlet 636 of the main flow cavity. The main panel 700 is configured to interact with the mask frame 670 to substantially isolate the main flow cavity 636 from the flushing flow channel 684 at the location where the mask frame and the cushion module are attached. The cavity wall 634 curves upward from the inlet 632 towards the side of the seal member 620 (as shown in FIGS. 30 and 32 - 34).

[0570] The cavity wall 634 is recessed from the composite nasal openings 626, 630 and is connected to the seal member 612 adjacent to the rim 638 by a tether 710 that is recessed from the rim 638 of the nasal openings 626, 630 to avoid contact with the patient. 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 anterior chamber under the nostrils when the mask 610 is worn on the patient, as described above with reference to mask 410 (FIGS. 32 and 37). The deflector panel 706 is directly connected around the perimeter of the nasal openings 626, 630 at its lateral sides and is connected by the tether 710 to proximal and distal points around the perimeter of the nasal openings 626, 630. In another aspect, the deflector panel 706 may be connected to the seal member 612 at a location spaced from the nasal openings 626, 630 at its lateral sides. The tether 710 curves downwardly from around the perimeter of the nasal openings 626, 630 and joins the rim 708 of the deflector panel 706. Thus, the tether 710 does not contact the patient when the mask 610 is worn.

[0571] The shear panel 704 of the cavity wall 634 provides at least one region of preferential deformation. The shear panel 704 is along the perimeter of the deflector panel 706 and thus has a generally U-shaped form (FIG. 35) to extend around the perimeter of the deflector panel 706 from one side of the nasal 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 the main panel 700.

[0572] It will be understood that the deformation region separates 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. Further, the two portions of the cavity wall (i.e., the upstream main panel 700 and the downstream deflector panel 706) are each shaped to withstand deformation. The separation is such that, as seen in FIGS. 32 - 35 and 37, the deflector panel 706 is inclined with respect to the main panel, and thus the reciprocating motion of the deflector panel 706 would be resisted by the main panel 700 if they were directly connected to each other. However, the shear panel 704 forms a flexible connection between the deflector panel 706 and the main panel 700 so that the deflection of the deflector panel 706 is absorbed (i.e., not transmitted to the main panel 700) by the shear panel 704 up to a limit. 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 thus the shear panel 704 deforms preferentially before the deflector panel 706 or the main panel 704 deforms. The shape of the shear panel 704 is selected such that the shear panel 704 rolls thereon when either or both of the main panel 700 and the deflector panel 706 translate relative to each other. As a result, when the seal member 612 is subjected to a deformation force, the main panel 700 and the deflector panel 706 transmit the deformation force to the deformation region (e.g., the shear panel 704), so that the shape of the flushing flow cavity 628 is substantially maintained such that the deformation of the cavity wall 634 is substantially limited to the deformation region.

[0573] Since deformation concentrates on the shear panel 704, the deflector panel 706 and the main panel 700 generally remain in their original shape and / or relative positions to each other, thus keeping the flushing flow cavity 628 open for the free flow of breathing gas. The likelihood of buckling or folding of the deflector panel 706 and the main panel 700 so as to block the flushing flow cavity 628 is reduced, thereby reducing the partial or complete occlusion of the flushing flow cavity 628. Further, since the preferential deformation concentrates on the shear panel 704, the resistance to the flow through the flushing flow cavity is unlikely to increase significantly. This means that the required flow rate ratio of the breathing gas through the main flow cavity 636 and the flushing flow cavity 628 is generally maintained, thereby providing effective treatment to the patient. The deflections that will generally be accommodated by the preferential deformation of the shear panel 704 and the slight deformation of the deflector panel 706 are those associated with different face shapes and the adjustment of the mask 610 on the patient's face.

[0574] As described above, the ratio of the cross-sectional areas of the flushing flow outlet 630 and the nasal outlet 626 provides control of the flow of breathing gas for effective treatment including flushing of the anatomical dead space. In this embodiment, the cavity wall 634 is connected to the rims 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 resists changing the cross-sectional areas of the flushing flow outlet 630 and the nasal outlet 626 when the seal member 620 deforms. Maintaining the ratio depends on maintaining the deflector panel 706 in a position recessed with respect to the nasal openings 626, 630. This is facilitated in this embodiment by a reinforcing bead 712 (FIG. 34) extending around the rims 638 of the nasal openings 626, 630. The bead 712 has a wall thickness greater than the wall thickness of the surrounding seal member so that the bead 712 is less flexible (i.e., more difficult to deform) than the surrounding seal member and thus resists occlusion or deformation of the nasal opening. 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 exposed to elevated gas pressure during treatment. Thus, the deflection of the nasal cradle 622 is concentrated by the bead 712 and the tether 710 up to the deflector panel 706. However, the curved shape of the deflector panel 706 renders it relatively rigid compared to the shear panel 704, and as a result, the deflection of the deflector panel 706 is transmitted to the deflecting shear panel 704. That is, even if the seal member 620 deforms to some extent, the deflector panel 706 remains in its position relative to the nostrils so that a prechamber formed between the end of the deflector panel 706 and the nostril remains. Thus, by preferentially deforming the shear panel 704 to some extent, buckling or deformation of the deflector panel 706 and the main panel 700 can be avoided. Beyond the point at which deformation of the deflector panel 706 and the main panel 700 occurs, it will be understood that their configuration means that they deform to limit the extent to which the flushing flow cavity 728 is occluded.Accordingly, the mask 610 accommodates a wider range of face shapes and thus reduces the likelihood that the flushing flow cavities 628 and the nose openings 626, 630 will be blocked.

[0575] In use, when the mask 610 is worn, forces are applied to the surface of the seal member 612 that contacts the face due to different face shapes, headgear preferences, and pressure settings. These forces and the locations where they are applied vary. However, the configuration described above concentrates the forces and deflections in the preferred deformation regions (i.e., the shear panel 704 in this embodiment), resulting in predictable crushing and rebounding movements. The predictable buckling pattern achieved through the preferred deformation regions allows the mask 610 to be designed such that the resulting deformation and compression in the elastomeric material forming the seal member 612 occur in a manner that keeps the openings and cavities unblocked when forces are applied to the seal. Without the preferred deformation regions, the collapse of the deflector wall 706 would be unpredictable and could result in inconsistent flow through the openings and cavities of the mask 610. This would lead to inconsistencies in the therapy, comfort, donning procedure, and overall performance achieved both between uses on the same patient and between different patients.

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

[0577] As shown in FIGS. 36 to 41, the mask 610 includes a mask frame 670 having the same overall form as described in the above-described embodiment. Specifically, the mask frame 670 includes a body 672 having side wings 674, and each of the side wings includes upper and lower connector bars 676 for attaching the mask frame 670 to a headgear that holds the mask 610 on the patient's face.

[0578] FIGS. 38 to 40 show the structure and flow paths of the mask frame 670. In particular, the mask frame 670 has a single main flow path inlet 680 that leads to a main flow channel 682. Downstream of the main flow path inlet 680, there is a partition 734 that divides the flow of respiratory gas between the main flow channel 682 and the flushing flow channel 684. The cross-sectional area of each of the main flow channel 682 and the flushing flow channel 684 is selected to provide a flushing flow for flushing the anatomical dead space and to provide the required volume flow rate of respiratory gas for breathing. FIGS. 37 and 38 show that the area of the inlet to the flushing flow channel 684 is larger than the total area of the inlets to the main flow channel 682, and thus the flow through the flushing flow channel 684 has a lower resistance to flow (at least at the inlet) than the flow through the main flow channel 682. However, this may be reversed or adjusted in other embodiments to correct for the bias in the flow 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 connects to the 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 is firmly pressed against the upper surface of the main panel 700 to form a generally airtight seal. Thus, the 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 the outlet 754 between the lower surface of the partition wall 750 and a U-shaped lip 730 that extends proximally from the mask frame 670. The breathing gas exiting the outlet 754 moves to the main flow cavity 636, from where the breathing gas is delivered to the patient via the mouth opening 624, the nose opening 626, or both.

[0580] To connect the cushion module 620 to the mask frame 670, the mask frame 670 includes a sheet 728 formed as a groove by a ledge 724 that extends proximally and a retaining wall 726 that extends generally perpendicular to the ledge 724 and generally parallel to the body 672. Further, 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 sheet 728, and the lower rim 724 of the opening 654 is passed over the bead 732 and seats tightly outside the lip 730 to form a generally airtight seal between the opening 654 and the mask frame 670. Further, the mask frame 770 is cooperative with the cavity wall 634 to separate the main flow cavity 636 from the flushing flow cavity 628.

[0581] When the shape of the face and the state of the headgear are different, during use, at least a portion of the flow path to any of the mouth opening 624, the nose outlet 626, or the flushing flow outlet 630 may be blocked. When this occurs, it may not be possible to deliver the required flow rate to achieve the necessary pressure to be delivered to the patient through the restriction point (usually the point where the flow branches) of the unblocked flow path.

[0582] To address this, the partition 734 includes a pressure relief valve in the form of a flap valve, a mushroom valve or a flexible poppet valve 760, which enables breathing gas from the flushing flow channel 684 to move through the valve opening 736 into the main flow channel 682 (Figs. 39 and 40). The poppet valve 760 includes a stem 754 that seats on a valve seat 738 and also includes a cap 752 from which the stem 754 projects from its central point. The cap 752 has a generally domed shape with an outer rim that extends beyond the valve opening 736 and contacts the partition 734 when the poppet valve 760 seats on the valve seat 738 to form a seal that separates the breathing gas in the flushing flow cavity 684 from the breathing gas in the main flow channel 682 (as shown in Fig. 41A).

[0583] At least the cap 752 is formed of an elastic elastomeric material, and the elasticity of the material is selected such that when the breathing gas in the flushing flow channel 684 exceeds a threshold gas pressure, the breathing gas in the flushing flow channel 684 can flow into the main flow channel 682. When the threshold pressure is exceeded, the cap 752 flexes away from the partition by the gas pressure (as shown in Fig. 41B), thereby breaking the seal and allowing the breathing gas to flow from the flushing flow channel 684 into 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 is blocked, the breathing gas continues to flow through the flushing flow channel 684, thereby delivering breathing gas to the patient despite the blocked flow path. Such a combination of flows enables an appropriate therapeutic pressure to be delivered through only one of the flow path openings (i.e., one of the mouth opening 624, the nose outlet 626 or the 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] Since the sizes of the flushing flow channel 684 and the main flow channel 682 are different in alternative embodiments to provide alternative therapies, the valve 740 can be configured to allow the flow of breathing gas from the main flow channel 682 to the flushing flow channel 684, or can be configured bidirectionally to allow gas to flow in both directions between the main flow channel 682 and the flushing flow channel 684, which will be understood.

[0585] Although not wishing to be bound by any particular theory, the applicant believes that the interface 610 operates during the inhalation and exhalation phases of the breathing cycle in the manner shown in FIGS. 42A and 42B. Specifically, during the inhalation phase (FIG. 42A), the breathing gas is substantially provided by the flushing flow supplied through the flushing flow cavity 628, but if the peak inhalation requirement exceeds the flow rate available through the flushing flow cavity 628, some of the flow may be entrained from the main flow cavity 636 through the nose outlet 626. In the exhalation phase (FIG. 42B), it is expected that the flow exiting the nasal cavity enters the main flow cavity 636 of the cushion module 620 (because the gas pressure in the main flow cavity 636 is relatively low compared to the gas pressure in the flushing flow cavity 628), and can be exhausted to the atmosphere through the bias flow vent 652. To achieve this, a gap needs to be formed between the nostril and the cavity wall 634 that separates the main flow cavity 636 and the flushing flow cavity. The recessed position of the rim 708 relative to the nose outlet 626 is thought to allow this flow arrangement to occur together with the deformation region formed in the cavity wall 634.

[0586] The problem of the flow of gas to the nostril or mouth opening being blocked or restricted through the seal member can occur in all of the described embodiments. Therefore, the pressure relief valve can be employed in any of the patient interfaces described above.

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

[0588] The mask 810 includes a seal member 612 and a housing 650 in the same form as the cushion module 620 described above with respect to the mask 610. However, in this embodiment, the housing 650 is different in that it does not include a bias vent hole for discharging exhaled breathing gas to the outside of the mask 810. The same reference numerals used in FIGS. 30 to 42 to describe the mask 610 are used in FIGS. 43 to 49 to indicate the same features in the mask 810. From this, the mask 810 includes a cavity wall 634 that is preferably deformable in the same manner as disclosed with respect to the mask 610, as shown in the figures. Therefore, the following description should be read on the premise that the same cavity wall 634 exists in the mask 810.

[0589] The mask 810 further includes a mask frame 870 that is different 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 the headgear. On the other hand, the mask frame 870 has a single main flow path inlet 880 for delivering breathing gas into the main flow cavity 636 through the opening 654 and also has a single outlet 888. Thereafter, the breathing gas can be inhaled by the patient through the mouth opening 624, through the nose outlet 626, or both. The mask frame 870 includes a main flow channel 882 having an inlet 880 that is relatively arranged with respect to its outlet 888 such that the breathing gas undergoes a small (0 to 5°) directional change along the length of the channel 882. In this embodiment, the inlet 880 is on the opposite side of the outlet 888. This arrangement gives a low resistance to the flow of gas in the main flow channel 882. With a single inlet 880 and a single outlet 888, it is possible to avoid a plurality of gas streams moving in opposite directions that can impede each other, so that the flow of breathing gas through the mask 810 is considered to be less restricted.

[0590] To connect the cushion module 620 to the mask frame 870, the mask frame 870 includes a seat portion 928 formed as a groove by a proximally extending ledge 924, and a retaining wall 926 extending generally perpendicular to the ledge 924 and generally parallel to the body 672. Further, 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 on the seat portion 928, and the lower rim 724 of the opening 654 is passed over the bead 932 and seats tightly outside the lip 930 to form a generally airtight seal between the opening 654 and the mask frame 870.

[0591] The mask 870 further differs from the mask frame 670 in that there is no inlet for fresh breathing gas from a gas source to the flushing flow cavity. Instead, the mask frame 870 includes a bias vent hole 652 in the body 672 below the ledge 924. Thus, the cavity is an exhaust cavity 940 as shown in FIGS. 45 - 47, and exhaled breathing gas (from the mouth, from the nostrils, or both) flows through the exhaust cavity 940, and the exhaled breathing gas flushed from the dead space within the patient's nasal cavity flows through the exhaust cavity 940 (FIG. 46) and out through the bias vent hole 652. The mask frame 870 cooperates with the cavity wall 634 to separate the main flow cavity 636 (i.e., the first cavity) from the exhaust cavity 628 (i.e., the second cavity). More specifically, the partition wall 950 is firmly pressed onto the upper 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 and is instead discharged from the mask 810 via the bias vent hole 652. Further, the gas exhaled from the mouth is sent to the exhaust cavity 940 together with the breathing gas as shown in FIG. 47, from where the exhaled gas is discharged from the mask 810.

[0592] The seal member 612 and the housing 650 are the same as in the previous embodiments, but the effect of the mask frame 870 is different. Specifically, it is the position of the exhaust vent in the exhaust cavity 940 having a single flow path leading to the main flow cavity 636 that provides more efficient exhaust and the induction of a flushing flow either into the user's anatomical dead space (in the case of mouth breathing) or into the nostrils (in the case of nasal breathing) where there is actually no dedicated flushing flow channel. In order for the breathing gas and the exhaled gas to exit the mask 810, one of the following is required: a) Flushing the exhaled breath from the user's oral cavity and nasal cavity during exhalation by passing through the mouth and flowing out of the nose, or b) Flowing through the partition wall, which creates a flushing flow towards the nostrils due to the flow path being restricted in that region of the cushion module 620 because the partition wall is close to the patient. Thus, in any of the above situations, the user'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 an example of a connection. Other arrangements may be adopted provided that the connection is capable of withstanding the elevated gas pressure. For example, the above-described connection allows the cushion module 620 to be separated from the mask frame 870 for cleaning. However, this connection can be a permanent connection. In a further alternative, the mask frame 870 and the housing 650 can be integrally formed so that the cushion module can be overmolded later to form an integral patient interface.

[0594] In previous embodiments, flushing of the anatomical dead space is provided by accelerating breathing gas through the flushing flow cavity and into the patient's nostrils. In mask 810, flushing of the anatomical dead space is thought to 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 opens their mouth and exhales through their nose. According to this scenario, at the end of exhalation, fresh pressurized breathing gas enters the patient's mouth through the mouth opening 624 from the main flow cavity 636. It then flows into the throat, rises through the nasal cavity, exits through the nostrils into the exhaust cavity 940, and exits to the atmosphere through the bias vent hole 852. The flow of fresh breathing gas entering through the mouth and exiting through the nostrils has the effect of flushing the anatomical dead space by removing the exhaled breathing gas rich in carbon dioxide remaining in the throat and nasal cavity at the end of the exhalation phase.

[0595] FIG. 46 shows another scenario in which flushing of the anatomical dead space is thought to occur when the patient's mouth is closed. (FIG. 46 is a schematic cross-sectional view and appears as if the patient's mouth is open, but the patient's mouth should be read as being closed). While exhaling through the nose with the mouth closed, fresh pressurized breathing gas enters the main flow cavity 636 and moves between the cavity wall 634 and the portion of the seal member 622 that contacts the patient's upper lip. In the absence of such a portion, the patient's upper lip forms the side of a flow path such that fresh pressurized breathing gas enters the main flow cavity 636 and moves between the cavity wall 634 and the patient's upper lip while exhaling through the nose with the mouth closed. Since this flow path has a small cross-sectional area, the speed of the breathing gas increases, thereby forming a jet of breathing gas. This jet enters the patient's nasal cavity, mixes with the exhaled breathing gas, and flushes the anatomical dead space rich in carbon dioxide due to a combination of increased speed and turbulence of the gas entering the patient's nostrils. The exhaled breathing gas enters the exhaust cavity 940 and exits to the atmosphere through the bias vent hole 652.

[0596] Figure 47 shows a third scenario in which flushing of the anatomic dead space is thought to occur when the patient exhales through the mouth. In this scenario, it is expected that the exhaled breathing gas rich in carbon dioxide fills the nasal cavity. However, in mask 810, during exhalation through the mouth, fresh pressurized breathing gas enters from the main flow cavity 636 and moves 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 the carbon dioxide-rich anatomic dead space. However, another portion of the jet flows into the exhaust cavity 940 over the rim 708 of the cavity wall 634, creating a Venturi effect that is thought to draw gas from the nasal cavity, including at least a portion of the exhaled breathing gas. The exhaled breathing gas from the nasal cavity and from the main 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, the breathing gas is supplied through a single inlet to the main flow cavity 636. The single inlet, i.e., the main flow path inlet 680, is formed as a large circular opening to reduce the resistance of the flow so that the pressure therapy received by the patient is not impaired. It is thought that the availability of fresh pressurized breathing gas supplied to the current embodiment always causes flushing of the anatomic dead space, regardless of whether the mouth is open or closed and regardless of whether the patient exhales through the mouth, nose, or both.

[0598] Similar to the other embodiments described above, the mask frame 870 can be permanently connected to the cushion module 620. This can be achieved by a suitable connection such as a snap-fit shape or welding known to those skilled in the art of patient interfaces. Alternatively, the mask frame 870 can be releasably connected to the cushion module 620 to enable separation and cleaning of the mask frame 870 and the cushion module 620 for cleaning and component replacement. This can also be achieved by a suitable connection known to those skilled in the art of patient interfaces, such as snap-fit, push-fit or interference fit.

[0599] Further embodiments of the patient interface 1010 are shown in FIGS. 50-70. This is a variant of the mask 810 shown in FIGS. 43-49, but the respiratory gas flow and dead space flushing functions remain the same as described above with reference to FIGS. 45-47. The patient interface 1010 includes a cushion module 1012, a frame 1014, and a conduit connector 1016 that includes elbows 1130 and socket inserts 1150.

[0600] The cushion module 1012 (FIGS. 50-52, 54, 61 and 62) is a variant of the cushion module 620 shown in FIGS. 30-35C. The cushion module 1012 includes a seal member 1020 that is fixed to a housing 1080 to define an internal volume. The internal volume is divided into first and second cavities by a cavity wall 1050. The first cavity is the main flow cavity 1032, and the second cavity is the exhaust flow cavity 1030 (also referred to herein as the exhaust cavity). The housing 1080 and the seal member 1020 are fixed by overmolding. The seal member 1020 is formed of a soft and elastic material such as silicone. It includes a mouth opening 1028 that surrounds the patient's mouth and also includes a nose opening 1024 when worn by the patient. A nose cradle 1022 is formed in the seal member 1020, and the nose opening 1024 is disposed in the valley thereof.

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

[0602] The nasal opening 1024 is disposed in the seal member 1020 to align with the patient's nostrils when the patient interface 1010 is worn on the patient. Thereby, for breathing during the respiratory cycle and for flushing the anatomical dead space, the respiratory gas can be transferred from the main flow cavity 1032 through the nasal outlet 1042 (see FIGS. 56 and 60) to the nostrils via the nasal opening 1024. The nasal outlet 1042 is recessed from the nasal opening 1024. By positioning the nasal outlet 1042 relative to the nasal opening 1024, excess respiratory gas from the main flow cavity 1032 can pass into the exhaust flow cavity 1030 and be exhausted to the surroundings through the vent opening 1090 of the housing 1080. The nasal opening 1024 is defined by a rim 1034 on the outer surface of the seal member 1020. However, considering that the nasal outlet 1042 and the opening to the exhaust flow cavity 1030 are recessed from the rim 1034, the nasal opening 1024 includes the volume between the level of the rim 1034 and the composite opening formed by the nasal outlet 1042 and the opening to the exhaust flow cavity 1030. It is through this volume, i.e., via the nasal opening 1024, that the respiratory gas can flow from the main flow cavity 1032 to the exhaust flow cavity 1030. In other words, the flow between the main flow cavity and the exhaust cavity occurs across the 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 the spaced relationship between this edge portion of the cavity wall and the nasal opening.

[0603] The 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 to blowout of the rim 1034 when the patient interface 1010 receives pressurized breathing gas from the flow generator. Also, the increased thickness of the rim 1034 increases the resistance of the rim 1034 to unwanted deformation that may occur when the patient interface 1010 is worn on a patient.

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

[0605] The cavity wall 1050 is configured to allow preferential deformation of the cavity wall 1050 in a way that reduces the likelihood of the exhaust flow cavity 1030 and the nasal opening 1024 being blocked. In this embodiment, the cavity wall 1050 is connected by a connecting member 1062 (see FIGS. 54 - 58) to a wall portion 1026 of a seal member 1020 that is between the nasal opening 1024 and the oral opening 1028. The connecting member 1062 directs the force applied to the wall portion 1026 to the cavity wall 1050 where the deflection force is absorbed. By doing so, the connecting member 1062 substantially maintains the position of the cavity wall 1050 relative to the nasal opening 1024 and the wall portion 1026. Another way to understand the effect of the connecting member 1062 is to understand that it clamps the cavity wall in place relative to the wall portion 1026. This allows the patient's treatment to continue with little interference to (a) the flow of breathing gas through the nasal outlet 1042, (b) the flow of breathing gas through the nasal opening 1024, and (c) the flow of breathing gas through the exhaust flow cavity 1030.

[0606] The connecting member 1062 functions in a similar manner to the tether 710 described above and shown in FIG. 37. That is, the connecting member 1062 clamps the cavity wall 1050 so that the distance of the wall portion 1026 from the cavity wall is substantially maintained when a deformation force is applied to the wall portion 1026. This reduces the likelihood of the nasal outlet 1042 being blocked. This substantially fixed distance also acts in other directions, and ballooning or blowing out of the wall portion 1026 away from the cavity wall 1050 is suppressed by the connection of the wall portion 1026 to the cavity wall 1050. Further, the connecting member 1062 concentrates the deformation force on the cavity wall 1050 that is designed to preferentially deform at a location away from the nasal opening 1024 so that the deformation is less likely to block the nasal opening 1024.

[0607] The deformation absorption effect is shown in FIGS. 59A - 59C, which also show that the cavity wall 1050 includes a deflector panel 1052, side panels 1054, a main panel 1056, and a deformation region 1074 that connects the side panels 1054 and the main panel 1056. The deformation region 1074 includes first and second elastic regions 1058, 1060 and first and second walls 1066, 1068. The deformation panel 1064 includes a first wall 1066 that protrudes from the first elastic region 1058 (see FIG. 58), a second wall 1068 that extends from the second elastic region 1060, and a connection portion 1070 that connects the first wall 1066 to the second wall 1068. The connection portion 1070 has a curved profile that, in the stationary state, coincides with the first direction of the first wall 1066 and with the end of the second wall 1068 that is remote from the second elastic region 1060.

[0608] The deformation region 1074 structurally separates the deflector panel 1052 from the main panel 1056. The separation occurs because the deformation panel 1064 accommodates a reduction in the distance between the first and second elastic regions 1058, 1060.

[0609] The deformation of the deformable panel 1064 occurs in two stages. In the first stage, when the second elastic region first displaces towards the first elastic region, the first wall is bent around the connection line with the first elastic region until it contacts or is adjacent to the lower side of the first elastic region. At this point, since the length of the second wall 1068 is longer than the length of the first wall 1066, there is still a gap between the first and second elastic regions 1058, 1060. 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 on top of the first wall 1066 (as shown in FIG. 59C) until the second elastic region 1060 contacts or is adjacent to the first elastic region 1058. This buckling and translational movement is sometimes referred to as "rolling". The 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 furthest from the second elastic region is the connection portion 1070. However, when the first wall 1066 reaches the limit of accommodating the displacement of the second elastic region 1060, the position of the connection portion 1070 becomes fixed. Therefore, when the second elastic region 1060 is further advanced towards the first elastic region 1058, the second wall 1068 will buckle with an increased curvature. The increased curvature will cause the second wall 1068 to adopt a U-shape with a bending point that shifts from the connection portion 1070 along the second wall 1070 to a position away from the connection portion 1070. When the second elastic region 1060 contacts the first elastic region 1058, the bending point shifts along the second wall 1068 such that a part of the second wall 1068 exceeds the bending point. In other words, when the second wall 1068 buckles and translates on top of 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 connection portion 1070 is fixed. However, the effect of shifting the buckling point (and thus the effect of changing the length of the second wall 1068 beyond the buckling point and behind the buckling point) remains unchanged.

[0611] Referring to FIGS. 55 and 56, the deflector panel 1052 is a curved panel having an end rim 1053 recessed from the level of the rim 1034 of the nose opening 1024 (shown by the dashed line R in FIG. 55). The recessed position of the deflector panel 1052 ensures that the deflector panel 1052 does not touch the patient's septum (which could cause discomfort), and provides a prechamber between the end of the deflector panel 1052 and the rim of the nose opening for breathing gas to flow from the main flow cavity 1032 to the nostrils or the exhaust flow cavity 1030. Preferential deformation of the deformation region 1074 ensures that the prechamber remains even if the seal member 1020 deforms. The deflector panel 1052 is joined to the side panel 1054 at its lower end and slopes upward therefrom towards the end rim 1053. Adjacent to the deflector panel 1052 is the wall portion 1026 of the seal member 1020 between the nose opening 1024 and the mouth opening 1028. The deflector panel 1052 is connected to the inner wall of the seal member 1020 on both sides of the nose opening 1024 beyond the bead 1036. This arrangement avoids further hardening of the bead 1036 and the rim 1034 that could affect the comfort of the patient.

[0612] The seal member 1020 is configured to accelerate breathing gas through the main flow cavity 1032 and direct the accelerated breathing gas toward the nasal opening 1024. In particular, the deflector panel 1052 and the wall portion 1026 define a channel leading to the nasal opening 1024. The channel terminates at the nasal outlet 1042, i.e., is recessed from the nasal opening 1024. The channel provides a taper to the main flow cavity 1032 formed between the deflector panel 1052 and the wall portion 1026. In other words, the cross-sectional area formed between the deflector panel 1052 and the wall portion 1026 in the main flow cavity 1032 decreases while leading to the nasal opening 1024. This taper accelerates the flow of breathing gas through the channel. Depending on the point in the breathing cycle, the accelerated breathing gas enters the nostrils to provide flushing of the anatomical dead space.

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

[0614] In this embodiment, the method further includes exhausting breathing gas from the exhaust flow cavity 1030 within 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 practice, the exhaled breathing gas from the mouth and the excess breathing gas within the primary flow cavity flow into the exhaust flow cavity 1030 by virtue of their fluid communication. Further, the exhaled breathing gas from the nostrils flows into the exhaust flow cavity 1030. In this embodiment, the 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 rim 1034 of the nasal opening 1024 and a prechamber formed when the cushion module 1012 is worn such that the patient's nostrils are positioned above the nasal opening 1024.

[0615] The side panel 1054 extends around the lower end of the deflector panel 1052 and extends laterally outward to join the inner sidewall of the seal member 1020. Also, the lateral side surface of the side panel 1054 extends in a concave shape upward from the deflector panel 1052. The main panel 1056 extends upward from the connection line with the housing 1080. In this embodiment, the housing 1080 includes a series of inner overmold windows 1092 (see FIGS. 63 and 64), through which the main panel 1056 is overmolded with the housing 1080 when overmolding the seal member 1020 with the housing 1080 to form the cushion module 1012. The material used to form the seal member 1020 flows through the overmold window 1092 during molding such that the material takes the shape of the housing 1080 and the window 1092 before solidifying or curing. The mechanical connection with the housing is obtained by the material extending through the window 1092. The window 1092 can take the form of an opening extending completely through the housing 1080.

[0616] The deformation region 1074 connects the side panel 1054 to the main panel 1056. It includes the first and second elastic regions 1058, 1060 (FIG. 60) and a deformation panel 1064 including the first and second walls 1066, 1068. The first elastic region 1058 connects the deformation region 1074 to the end wall. It generally has a polygonal profile and a profile similar to the concave contour of the main wall. In this embodiment, the first elastic region 1058 smoothly merges with the main wall when extending laterally towards the side surface of the seal member 1020.

[0617] The second elastic region 1060 abuts against the lower end of the deflection panel 1064 and is elongated. It is arranged generally parallel to the first elastic region 1058. The second elastic region 1060 is at least as wide as the nose opening 1024. It has this shape to function as a load distributor for the forces transmitted via the connecting member 1062. However, in other embodiments, it can be wider than the nose opening 1024. The second elastic region 1060 is formed as a rib with discrete ends in this embodiment, but in other embodiments, it can be smoothly tapered towards the side panel 1054. The connecting member 1062 extends from the connection line at the wall portion 1026 (A in FIG. 55) to the connection line (B in FIG. 57) and is located under the second elastic region 1060. The connecting member 1062 increases (i.e., stiffens) the repulsive force of this region of the cavity wall 1050. From this, the force applied to the wall portion 1026 in the direction of the housing 1080 is transmitted to the second elastic region 1060 which is urged towards the first elastic region 1058. However, the first and second elastic regions 1058, 1060 are configured to promote the deformation of the deformation panel 1064 rather than the deformation of the main panel 1056, the side panel 1054 or the deflector panel 1052.

[0618] Figures 59A - 59C show the sequence of initial and subsequent deformations of the seal member 1020 when a deforming force is applied through the wall portion 1026. The patient interface 1010 is shown in a stationary state in Figure 59A with the first and second elastic regions 1058, 1060 spaced apart. When a force is applied through the connecting member 1062, deformation is absorbed by the deformation of the first and second walls 1066, 1068 due to their relatively thin wall thickness compared to the relatively thick wall thickness of the first and second elastic regions 1058, 1060. This occurs first by the first wall 1066 being bent under the first elastic region 1058 as the spacing between the first and second elastic regions 1058, 1060 decreases (as shown in Figure 59B). As the spacing further decreases due to additional deformation applied through the wall portion 1026 and the connecting member 1062, the first wall 1066 is bent flat relative to the underside of the first elastic region 1058 and the second wall 1068 buckles and rolls on top of the first wall 1066 (as shown in Figure 59C). This rolling motion continues until the first elastic region 1058 abuts the second elastic region 1060.

[0619] The first wall 1066 extends below the level of the first elastic region 1058. In the profile, the angle between the lower surface of the first elastic region 1058 and the first wall 1066 is in the range of 5° to 135° in the stationary state. However, in the embodiments shown in FIGS. 50 to 70, the angle at rest is 85°. It has a contour along the contour of the first elastic region 1058 and is tapered inwards towards its end. As a result of the taper, the imaginary line following the intersection of the first elastic region 1058 and the first wall intersects the imaginary line following the line of the connection part 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. The first elastic region 1058 has a wall thickness that is at least three times the wall thickness of the first wall 1066 to ensure that the first wall 1066 deforms preferentially over the first elastic region 1058.

[0620] The connection part 1070 is arranged at the end of the first wall 1066 remote from the first elastic region 1058, and the second wall 1068 extends from the second elastic region 1060 to intersect the connection part 1070. In the present embodiment, both the connection part 1070 and the second wall 1068 follow the concave contour of the first wall 1066. The second wall 1068 initially extends from the second elastic region 1060 in a direction inclined downward from the plane intersecting the second elastic region 1060 and the curved corner 1070. However, the second wall 1068 curves upward away from the second elastic region to intersect the connection part 1070. Further, the second wall 1068 has a taper with an increasing thickness from the connection part 1070 towards the second elastic region 1060. Both the curve and the taper of the second wall 1068 allow the initial deformation of the deformable 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] The second wall 1068 has a length in the range of 2 mm to 15 mm. Optionally, the length is within the range of 2 mm to 10 mm. In the embodiments shown in FIGS. 50 - 70, the second wall 1068 has a length of 5 mm. This length can vary depending on the amount of movement required to absorb the deformation of the seal member 1020. The thickness of the second wall 1068 can vary from 0.15 mm where it joins the curved corner 1070 to 2 mm where it joins the second elastic region 1060. In the illustrated embodiment, the thickness is in the range of 0.27 mm to 0.4 mm.

[0622] The shapes and thicknesses of the first and second walls 1066, 1068 are selected such that the cushion module 1012 can accommodate a wide range of face shapes and deformation forces associated with the application and use of the patient interface. However, it is possible to manufacture different cushion modules to fit specific ranges of face shapes that fall towards the ends of the face shape spectrum.

[0623] The first and second elastic regions 1058, 1060 are formed with a greater wall thickness to provide greater elasticity compared to the deformation panel 1064, and 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 elastic regions 1058, 1060 can be stiffened by alternative means, provided that the deformation panel 1064 deforms preferentially when force is applied to the seal member 1020. For example, the first and second elastic regions 1058, 1060 can be formed of a more elastic material (such as different grades of silicone or plastic material) or can have a different structure.

[0624] The housing 1080 (shown in more detail in FIGS. 61 - 65) has a body 1082 with front and rear faces 1112, 1114. The rear face forms part of the main flow cavity 1032 and the exhaust flow cavity 1030. The periphery of the body 1082 includes an outwardly projecting tab member 1084 and a bead 1036 disposed at the end of the tab member 1084 that defines a series of outer overmold windows or openings 1088. The seal member 1020 is overmolded with the window to form a permanent mechanical connection and seal between the housing 1080 and the seal member 1020.

[0625] As described above, the inner overmold window 1092 (FIGS. 63 and 64) is formed in the housing 1080 extending in a U - shape across the body 1082. The inner overmold window 1092 extends from and returns to the outer overmold window 1088 across the upper portion of the body 1082. A group of vent openings 1090 are disposed within the region bounded by the inner overmold window 1092 to allow breathing gas to be exhausted from the exhaust flow cavity 1030 to the ambient.

[0626] The pressure port 1094 is disposed laterally on the lower side of the body 1082, and the breathing gas inlet opening 1096 is disposed at the lower central position of the body 1082. The inlet opening 1096 is adapted to connect the frame 1014 and the conduit connector 1016 to 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 functions as an important shaped part to assist in holding the frame 1014 and the socket insert in alignment with the cushion module 1012. Specifically, the conduit connector 1016 is inserted into the inlet opening 1096 and captures the frame 1014 between the conduit connector 1016 and the housing 1080. This arrangement, in addition to controlling alignment, also allows the conduit connector 1016 and the frame 1014 to be released from the cushion module 1012 and reassembled as needed.

[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 a ventilator. The other end of the elbow 1130 has a channel 1140 that connects the tapered connection to a neck portion 1138, which in turn transitions to 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 inner wall 1154 that tapers inwardly. The inner taper cooperates with the neck portion 1138 and the ball element 1134 of the elbow 1130 to provide rotationally free movement in the longitudinal and transverse directions. Also, an outer wall 1156 defines a first lip 1162 that includes a shaped portion 1158 that interacts with the recess 1106 of the housing 1080 to limit the rotational movement of the socket insert 1150 and the frame 1014 relative to the mask housing 1080. The socket insert 1150 further has two fingers 1160 (Figs. 69 and 70) that extend axially from the flange 1152. Each finger 1160 has an outer wall 1156 that corresponds to the shape inside the sleeve 1098 and an inner wall 1168 that corresponds to the outer surface of the ball element 1134, so 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 to define a second lip 1172 that projects radially.

[0630] In the assembled patient interface 1010, the socket insert 1150 sandwiches the frame 1014 against the housing 1080 as part of the interference fit between the conduit connector 1016 and 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 contour of the cushion module 1012. The frame 1014 enables the patient interface 1010 to be connected to a headgear that holds the patient interface 1010 in a predetermined position during treatment. For this purpose, the frame 1014 includes upper and lower headgear connection points 1116. A standard headgear connection 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] Frame 1014 includes a conduit opening 1122 through which a conduit connection 1016 passes for connection to the housing 1080. To facilitate this, frame 1014 has a stepped profile (see FIG. 68) that is recessed from the front face 1112 and defines arcuate shoulders 1126 that face each other so as to define upper and lower recesses 1128 therebetween, and includes a conduit opening 1122. The innermost perimeter of the conduit opening 1122 is dimensioned to fit around the inlet opening 1096 of the housing 1080. When assembled with the cushion module 1012, the recesses 1128 are shaped to receive the shaped portions 1158 of the socket inserts 1150. This interaction between the recesses 1128 and the shaped portions 1158 fixes the orientation of the frame 1014 relative to the cushion module 1012.

[0632] However, it will be understood that frame 1014 can be connected to housing 1080 by any conventional means such as adhesion or welding. Also, frame 1014 includes a bias vent opening. In the patient interface, the bias vent opening 1118 is aligned with the vent opening 1090 of the housing 1080 to allow exhaust breathing gas from the exhaust flow cavity 1030 to be discharged ambiently without interference with the frame 1014.

[0633] This embodiment includes a frame 1014, but in alternative embodiments, the headgear connection points can be integrated with or connected to the housing 1080. In such cases, the frame 1014 is not necessary and can be omitted in such embodiments.

[0634] As shown in FIG. 54, the conduit connector 1016 and the frame 1014 are assembled to the housing 1080 by fitting the fingers 1160 of the socket insert 1150 through the sleeve 1098 such that the second lip abuts the inner end wall 1100. This includes positioning the frame 1014 between the socket insert 1150 and the housing 1080 and aligning the shaped portions of the socket insert 1150 with the recesses of the frame 1014 and the housing 1080. The socket insert 1150 is then pushed into and inserted through 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, the cushion module 1212 (FIG. 71) is provided in a similar form to the cushion module 1012 but is 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. The housing 1280 includes a tab member 1284, a bead 1286, an outer overmold window 1288, and a pressure port 1294, which are the same as their corresponding ones in cushion module 1012. The description of those features regarding cushion module 1012 is equally applicable to the corresponding features of cushion module 1212 shown in FIGS. 73 and 74. However, in housing 1280, an inlet opening 1296 is disposed centrally and extends a short distance from the outer overmold window 1288. In contrast to cushion module 1012, bias vent openings 1290 are grouped on each side of the inlet opening 1296. This is a result of the inlet opening 1296 extending across the top of the housing 1280 near the outer overmold window 1288. The inner overmold window 1292 forms a boundary with the outer overmold window 1288 around each group of the bias vent openings 1290. In this embodiment, the inner overmold window 1292 is arranged in a W shape. This shape results in a corresponding W-shaped inner overmold 1240 of the seal member 1220 as seen in FIG. 71.

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

[0638] The cushion module 1212 includes a cavity wall 1050 that includes a deflector panel 1052, a side panel 1054, and a deformation region 1074 that are the same as their corresponding ones in the cushion module 1012. The description of those features regarding the cushion module 1012 is equally applicable to the cushion module 1212, and the corresponding features are shown in FIG. 72. However, instead of having a main panel 1056 that contacts the housing 1280 along a U-shaped contact line following the inner overmold window 1092, the main panel 1056 of the cushion module 1212 traces a W-shaped contact line with the housing 1280. As a result, the main panel 1056 extends downward from a first elastic region 1058 that is deeper in the side region of the end wall than the central portion of the main panel 1056.

[0639] In a further alternative embodiment, the main panel 1056 can be formed without overmolding the housing 1280 such that the inner overmold 1240 is omitted. In such an embodiment, the bias vent opening 1290 can be formed in the seal member 1220 instead of the housing 1280 such that the main panel 1056 joins with the seal member 1220. Alternatively, the main panel 1056 can abut or interact with the housing 1280 to form a seal, for example, by adhesion or welding.

[0640] To correspond to 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, a pressure port opening 1620, a conduit opening 1622, and a recess 1628 that are the same as their corresponding ones within the frame 1014. The description of those features regarding the frame 1014 is equally applicable to the frame 1614, and the corresponding features are shown in FIG. 75. However, the frame 1614 is different in that when the frame 1614 is combined with the cushion module 1212, the bias vent opening 1618 is located laterally of the conduit opening 1622 and aligns with the bias vent opening 1290 of the housing 1280.

[0641] Alternative embodiments of the patient interface can be adapted to be connected 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. A patient interface configured in this way is known as a dual rim patient interface. Instead of discharging the exhausted breathing gas into the atmosphere, they can capture the exhausted breathing gas and return it to the flow generator.

[0642] Three different embodiments of the dual rim patient interface are described below, each based on the concepts of coaxial, split inlet, and separated inlet conduit arrangements. Although these embodiments are described with respect to different cushion modules, it will be understood that the conduit arrangement concepts can be adapted to operate with other cushion modules disclosed herein or other available or known cushion modules.

[0643] In each of the following embodiments, by incorporating a bias leak into the expiratory flow path, the bias flow is increased. The bias leak can be adjustable. Further, the bias leak can 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 rim setting.

[0644] Bias leakage is thought to induce a higher bias flow rate, which is expected to improve the flushing of dead space during use of the patient interface disclosed herein. Thus, bias leakage can render the patient interface described herein suitable for use with a flow generator or ventilator that provides an insufficient gas flow rate to effect flushing of the anatomical dead space in a dual rim configuration. In other words, the patient interface described herein can render some flow generators or ventilators useful for the flushing procedure of the anatomical dead space during operation in a dual rim configuration.

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

[0646] In the embodiment shown in FIGS. 76-81, the inlet path 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 such that the inner conduit 1342 defines the exhaust path and the outer conduit 1344 defines the inlet path. The conduit can be of any length. Optionally, the length is sufficient to disconnect the force between the cushion module 1012 and the intake and exhale rims (conduits) of the flow generator or ventilator.

[0647] The coaxial conduit 1340 is connected to a frame 1310 adapted to extend an inlet path 1324 to an inlet opening 1096 of the cushion module 1012 and an exhaust path 1326 from a bias vent opening 1090 of the cushion module 1012 to an outer conduit 1344. More specifically, the frame 1310 has an inner duct 1316 defining an inner passage 1318 that connects to an inner conduit 1342 to extend the inlet path 1324 of the coaxial conduit 1340 to the inlet opening 1096 of the cushion module 1012. This connection is made via an inner conduit connection flange 1336. The inner duct 1316 interacts with the inlet opening 1096 to deliver breathing gas from the inlet path 1324 to the main flow cavity 1032 of the cushion module 1012. Similarly, the frame 1310 has an outer duct 1320 surrounding the inner duct 1316 and defining an outer passage 1322 that connects the bias vent opening 1090 to the outer conduit 1344. This connection is made via an outer conduit connection flange 1338. In this arrangement, the exhaust path 1326 extends from the cushion module 1012 through the outer passage 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 region surrounding the vent opening 1090 to the cushion module 1012. More specifically, the flange 1334 is shaped to seal against an outer overmold 1038 of the cushion module 1012. In an alternative embodiment, the flange 1334 may be formed to seal against a portion of the inner overmold 1040 and the outer overmold 1038 to seal the cushion module 1012 and the outer passage 1322.

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

[0650] Any suitable connection for connecting the frame 1310 to the cushion module 1012 can be used to enable the flow of breathing gas between the cushion module 1012 and the frame 1310, and one option includes an interference fit connector. For example, the connector can include a series of deformable fingers on the frame 1310 that are deflected 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 a mating shape that interlocks with a corresponding shape on the frame 1310. Both shapes can be designed for an interference fit, a twist lock fit, a press fit, a tapered connection, or any other suitable connection configuration for securing the frame 1310 to the cushion module 1012.

[0651] Also, the partition wall 1328 includes an exhaust path opening 1332 that opens into the outer passage 1322. The flow of breathing gas entering the cushion module 1012 through the inner passage opening 1330 and the flow of breathing gas entering the exhaust path opening 1332 from the cushion module 1012 are shown by respective arrows in FIG. 79.

[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 and spaced intake and exhalation rims of a flow generator or a ventilator to the coaxial conduit 1340. The connector is configured to connect the inner conduit 1342 to the intake rim and the outer conduit 1344 to the exhalation rim. 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 formed as a funnel that transfers the flow of breathing gas from the intake rim into 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 connection to the intake and exhalation rims of the flow generator. In the embodiments shown in FIGS. 76, 78, 80, and 81, the inner conduit connector 1364 is continuous with the coaxial conduit 1340. However, the outer conduit connector 1362 branches from the side of the coaxial conduit connector 1360. The angle of the outer conduit connector 1362 relative to the inner conduit connector 1364 results in an acute change in the direction of the exhaust path 1326.

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

[0654] The coaxial conduit connector 1340 includes a bias flow vent 1368 configured to discharge gas from the exhalation path to the ambient atmosphere. The bias flow vent 1368 may be adjustable to vary the flow of breathing gas to the ambient atmosphere. For example, the flow may be adjusted to a flow within the range of 5 - 15 L / m. In this embodiment, the 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 the infection risk associated with the leaked breathing gas.

[0655] Furthermore, the bias flow vent 1368 can be configured to prevent connection to another conduit. Such a connection may block the flow of breathing gas through the bias flow vent 1368 and thus may reduce the dead space flushing effect provided by the patient interface. To address this, the bias flow vent 1368 includes one or more shaped portions that visually indicate that a removable conduit should not be connected to the bias flow vent 1368. The one or more shaped portions prevent a sealed connection with a removable conduit or prevent occlusion of the bias flow vent. In this embodiment, the shaped portions include three recesses 1370 formed in the end rim of the bias flow vent 1368.

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

[0657] Alternative embodiments of the dual rim patient interface 1400 are shown in FIGS. 82 - 85 and include a cushion module 620 as shown in FIGS. 30 - 34. The above description related to the cushion module 620 applies equally here to this embodiment.

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

[0659] As shown in FIGS. 82 and 85, in a single conduit 1416, channels 1420, 1424 are separated by a common partition wall 1432. However, channels 1420, 1424 branch as they extend away from the cushion module side end of the frame 1410 and become separate conduits, namely an intake conduit 1422 and an exhalation conduit 1418. The intake conduit 1422 associated with the inlet channel 1420 can be connected to the intake rim of a flow generator or a ventilator, and the exhalation conduit 1418 associated with the outlet channel 1424 can be connected to the exhalation rim of a flow generator or a ventilator. Similar to the coaxial conduit embodiment described above, each of the intake and exhalation conduits 1418, 1422 has a length sufficient to decouple the force between the cushion module 620 and the intake and exhalation rims.

[0660] As shown in FIGS. 83 and 84, the inlet and outlet conduits 1420, 1424 terminate at a composite opening 1426 at the cushion module side end of the frame 1410. The partition wall 1432 terminates at a cross member 1434 that extends across the composite opening 1426 of the single conduit 1416. Although the partition wall 1432 is shown as extending across the single conduit 1416, in an alternative embodiment, the frame 1410 may include a cross member 1434 that extends across the composite opening 1426 such that the partition wall 1432 intersects the cross member 1434 of the frame 1416 to separate the inlet channel 1420 from the outlet channel 1424. In either way, the partition 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 that separates the inlet channel 1420 from the outlet channel 1424. In this embodiment, as shown in FIGS. 84 and 85, the interaction includes the 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 with other forms of interaction that provide a seal between the partition wall 1432 and the cavity wall 634 are equally suitable.

[0661] The composite opening 1426 is bounded by a fitting member 1438 configured to couple a 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 upper and lower rims 720, 722 of an 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 a friction or interference fit shape that interacts with the upper and lower rims 720, 722. The single conduit 1416 may be formed with a friction or interference fit shape that enables a releasable coupling with the sleeve 1436. Alternatively, the single conduit 1416 may be adhered or welded to the sleeve 1436 or fixed 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 embodiments including coaxial conduits.

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

[0664] This embodiment is shown in FIGS. 86 and 87, and the patient interface 1500 includes the cushion module 1012 shown in FIGS. 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, and the first and second conduits 1520, 1530 are spaced apart.

[0665] In the present 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 the present embodiment, both conduits 1520, 1530 are in the form of a conduit connector 1016 that includes an elbow 1130 and a socket insert 1150, as shown in FIGS. 50 - 54. The frame 1510 is adapted to accommodate this stacked arrangement of the conduits 1520, 1530. However, in a variant of the present embodiment, one or both of the two conduits 1520, 1530 do not have a socket insert 1150 and an elbow 1130 that 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 can 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 biasing flow vent for discharging breathing gas to the surroundings.

[0668] Those skilled in the art of the present invention will understand 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 numerous 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, the features of one embodiment can be combined with the features of one or more other embodiments to achieve further embodiments.

[0670] In the following claims and the foregoing description, unless the context requires otherwise by express language or necessary implication, the words "comprise", "comprises" and variations such as "comprising" are used in an inclusive sense, that is, to specify the presence of the stated features but not to preclude or to exclude the presence or addition of further features in the various embodiments of the apparatus and methods disclosed herein.

[0671] In the foregoing description of the preferred embodiments, specific terms are used for clarity. However, the invention is not intended to be limited to the specific terms so chosen, and it is to be understood 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 "rear", "inner" and "outer", "above", "below", "upper" and "lower", "up" and "down" are used as convenient words to provide a reference point and are not to be construed as limiting terms. The terms "vertical" and "horizontal" used throughout this specification, including in the claims, in relation to the patient interface refer to the orientation relative to the normal operating orientation.

[0672] The reference in this specification to prior publications (or information derived therefrom) or known matters does not admit, approve or in any way suggest that prior publications (or information derived therefrom) or known matters form part of the common general knowledge in the field of endeavor to which this specification relates, nor should they be received as such.

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

Claims

**Claim 1** A non-invasive patient interface configured to deliver pressurized breathing gas to a patient's mouth and nostrils, the patient interface comprising a cushion module, (a) a seal for sealing around the patient's mouth and nostrils, (b) a housing connected to the seal, (c) an internal volume defined by the seal and the housing, wherein the cushion module includes a cushion module including the above, (d) the seal includes cavity walls disposed within the internal volume of the cushion module to define first and second cavities within the internal volume of the cushion module, the cushion module, (e) a preferential deformation region, which is part of the cavity wall, and includes first and second elastic regions and a deformation panel disposed between the first and second elastic regions, A non-invasive patient interface. **Claim 2** The seal includes a face contact portion between one or more nasal openings and one or more mouth openings, the second elastic region is connected to the face contact portion, and the seal is configured to direct an external deformation force on the face contact portion to the preferential deformation region such that the cavity wall preferentially deforms within the preferential deformation region. The patient interface according to claim 1. **Claim 3** The deformation panel includes first and second walls and a connection portion between the first and second walls. The patient interface according to claim 1 or 2. **Claim 4** The first wall projects in a first direction from the first elastic region, and the second wall projects in a second direction different from the first direction from the second elastic region. The patient interface according to claim 3. **Claim 5** The deformation of the deformation region involves a decrease in the distance between the first and second elastic regions and a related deformation of the deformation panel to accommodate the decrease in the distance. The patient interface according to claim 4. **Claim 6** The second direction is inclined downward with respect to the upright direction of the patient interface from a plane intersecting the second elastic region and the connection portion. The patient interface according to claim 4 or 5. **Claim 7** The connection part has a curved profile that, in a stationary state, aligns with the first direction of the first wall and aligns with an end of the second wall that is away from the second elastic region, for the patient interface according to any one of claims 4 to 6.

8. The second wall has a curved profile from the connection part to the second elastic region, and the second wall increases in thickness from the connection part to the second elastic region, for the patient interface according to any one of claims 4 to 7.

9. The deformation panel has a wall thickness less than the wall thickness of the walls of the first and second elastic regions, and the first and second elastic regions have a wall thickness at least three times the wall thickness of the deformation panel, for the patient interface according to any one of claims 4 to 8.

10. The cavity wall further includes a main panel that connects the housing to the first elastic region, for the patient interface according to any one of claims 4 to 9.

11. The cavity wall further includes a deflector panel that is recessed from a rim of one or more nasal openings and forms a channel configured to direct breathing gas from the first cavity to the one or more nasal openings, and the deflector panel abuts against the second elastic region, for the patient interface according to claim 10.

12. The main panel and the deflector panel are separated by the intervening deformation region, for the patient interface according to claim 11.

13. The cavity wall is arranged with respect to the one or more nasal openings and the one or more oral openings such that breathing gas can flow from the first cavity through the one or more nasal openings to the nostrils, for the patient interface according to any one of claims 2 to 12.

14. The cavity wall is arranged with respect to the one or more nasal openings and the one or more oral openings such that exhaled breathing gas from the mouth and nostrils can flow into the second cavity, for the patient interface according to any one of claims 2 to 13.

15. The cushion module further includes an exhaust vent for sending breathing gas from within the cushion module to the outside of the cushion module, the second cavity is an upper cavity disposed above the first cavity and communicates with the exhaust vent, and the exhaust vent includes one or more groups of openings. The patient interface according to any one of claims 1 to 14.

16. The housing includes the exhaust vent, and the connection of the cavity wall between the cavity wall and the housing at least partially surrounds the exhaust vent. The exhaust vent is defined 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. The patient interface according to claim 15.

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