Patient Interface

Abstract

The present disclosure relates to a patient interface for non-invasive ventilation. The patient interface includes an outer wall configured to seal around a patient's mouth and nares and defining an interior volume including a first chamber having one or more oral openings in gas communication with the mouth and a second chamber having one or more nasal openings in gas communication with the nares. The patient interface further includes a partition wall separating the first chamber from the second chamber. The patient interface further includes one or more flow directors that allow gas to flow from the first chamber to the second chamber or from the second chamber to the first chamber. The one or more flow directors are configured to direct the gas flow through the one or more nasal openings.

Description

[Technical field]

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

[0002] One of the current treatments for respiratory diseases such as restrictive thoracic disease, acute respiratory failure, advanced neuromuscular disease, chronic obstructive pulmonary disease (including COPD-emphysema, refractory asthma, and chronic bronchitis) is non-invasive ventilation (NIV). There is some evidence to suggest that NIV therapy may be useful in supporting breathing after intubation, including reducing the chance of reintubation. NIV therapy applies positive airway pressure to the lungs throughout the inhalation and exhalation cycle, opening the airway. This improves the flow of respiratory gases into and out of the lungs. Summary of the Invention [Problem to be solved by the invention]

[0003] However, one of the side effects of the positive pressure applied in current NIV treatments is that the applied treatment pressure can make the patient uncomfortable and therefore less willing to undergo treatment. A secondary effect of positive pressure is that the patient interface needs to be firmly attached to the patient to avoid leakage, thereby ensuring that pressure is maintained in the patient interface and respiratory system. This tight application of the interface can lead to pressure sores, especially for patients who are semi-conscious or unconscious and therefore unable to provide feedback regarding any pain caused to the patient's skin by the pressure of the patient interface.

[0004] NIV treatment creates two challenges: compliance (the degree to which the patient is willing to follow the treatment) and bedsores. In addition to these challenges, a further challenge for patients with obstructive respiratory disease is flushing carbon dioxide from the anatomical dead space. Specifically, the end of the expiratory cycle is characterized by a drop in the pressure of the exhaled breathing gas. This means that the carbon dioxide-rich breathing gas remains in the patient's throat, nose and mouth and is drawn back into the lungs at the beginning of the inhalation cycle. Therefore, replacing the carbon dioxide-rich breathing gas in these areas with a breathing gas that contains a higher concentration of oxygen than the carbon dioxide-rich breathing gas helps the patient achieve adequate breathing.

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

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

[0007] The invention will now be described with reference to a set of embodiments, however it will be understood that the invention may be defined by combining the features of two or more of the embodiments.

[0008] According to a first aspect there is provided a non-invasive patient interface configured to seal around a patient's mouth and nostrils, the patient interface comprising: (a) an outer wall defining an interior volume including a first chamber having one or more oral openings in gas communication with the mouth, and a second chamber having one or more nasal openings in gas communication with the nasal passages; (b) a partition wall separating the first chamber from the second chamber; (c) one or more flow directors that allow gas to flow from the first chamber to the second chamber, the flow directors configured to direct the gas flow through one or more nostril openings; Includes.

[0009] One or more flow directors may extend from the divider wall.

[0010] The one or more flow directors may be located in a central region of the partition such that each flow director is spaced apart from the periphery of the partition.

[0011] The one or more flow directors may extend from the partition wall into the first chamber, or into the second chamber, or into both the first and second chambers.

[0012] The one or more flow directors may extend towards one or more nostril openings.

[0013] A partition wall may be joined to the outer wall to separate the first chamber from the second chamber.

[0014] The partition wall may be joined to the outer wall at a location spaced from the one or more nostril openings.

[0015] The partition wall may join the exterior wall across the entire width of the exterior wall.

[0016] The partition wall may be joined to the outer wall between the at least one or more nostril openings and the at least one or more oral openings.

[0017] The partition wall may join the outer wall closer to the oral opening or openings than to the nostril opening or openings.

[0018] The outer wall may include a wall portion between the at least one or more nostril openings and the at least one or more oral openings, and a junction between the dividing wall and the wall portion may be located in a lower half of the wall portion. A width of the wall portion may be defined between the lateral outermost ends of the one or more nostril openings.

[0019] The one or more flow directors can define a gas flow path from the first chamber to the second chamber, the flow directors surrounding the gas flow path.

[0020] The flow director or directors may have a sealed junction with the partition wall.

[0021] The one or more flow directors may each have a second opening in the second chamber that is recessed from the one or more nostril openings.

[0022] Each of the one or more flow directors may have a second opening in the second chamber, the second opening spaced apart from the one or more nostril openings.

[0023] The second opening is defined by a rim, and the rim may be contoured such that at least a portion of the rim is substantially consistently spaced from the one or more nostril openings.

[0024] The portion of the rim that may be positioned substantially consistently spaced from the one or more nostril openings is adjacent an outer wall between the at least one or more nostril openings and the at least one or more oral openings.

[0025] The rim of each second opening may extend further from the partition wall laterally outer of the flow director than the rim extends from the partition wall laterally inner of the flow director.

[0026] The rim of each secondary opening may be disposed such that it is recessed further from the nostril opening laterally inward of the flow director than it is recessed laterally outward of the flow director.

[0027] The rim of each secondary opening may be recessed furthest from the nostril opening at a point between the laterally inner side of the flow director and the laterally outer side of the flow director.

[0028] At least a portion of the rim of the second opening may be concentric with at least a portion of the rim of the nostril opening.

[0029] The patient interface can include at least two flow directors spaced apart by a gap that allows breathing gas from the first chamber and exhaled breathing gas from the nares to flow into the second chamber.

[0030] The rim of each flow director may not extend as far from the partition wall on the same side as the gap as the rim extends on the side away from the gap.

[0031] The flow director may be configured such that the laterally outer side of the rim is adjacent to the lateral rim of the nostril opening, taking into account the direction of gas flow from the flow director.

[0032] The or each flow director may be configured such that a laterally outer side of the respective rim is adjacent a lateral rim of the nostril opening, having regard to the direction of gas flow from the respective flow director.

[0033] The flow director may be configured such that the laterally outer sides of the rim are aligned with the lateral rims of the nostril openings, taking into account the direction of gas flow from the flow director.

[0034] Alternatively, each of the one or more flow directors may have a second opening at the same height as the one or more nostril openings.

[0035] The flow director or directors may be spaced apart from the outer wall.

[0036] The one or more flow directors may be coupled to the outer wall.

[0037] According to a second aspect there is provided a non-invasive patient interface configured to seal around a patient's mouth and nostrils, the patient interface comprising: (a) an outer wall defining an interior volume of a patient interface, the outer wall having a patient engaging surface including one or more oral openings in gas communication with the mouth and one or more nasal openings in gas communication with the nares; (b) a partition wall separating the interior volume into a first chamber having one or more oral openings and a second chamber having one or more nostril openings; (c) one or more flow directors extending from the partition wall to allow gas to flow from the first chamber to the second chamber, the flow directors being configured to direct the gas flow through the one or more nostril openings; Including, The flow directors are spaced apart by spacing elements that maintain the spacing between the flow directors.

[0038] Each flow director can have a second opening defined by a second opening rim, the second opening rim being spaced apart from the patient engaging surface.

[0039] The second aperture rim may be recessed from the patient engaging surface.

[0040] Each flow guide can include a body defining a flow channel extending between a second opening of the second chamber and an inlet opening into the first chamber, where the body is spaced apart from the patient engaging surface.

[0041] The spacing elements may be disposed between the flow directors.

[0042] The spacing element may be coupled to the partition wall.

[0043] The spacing elements may connect the flow directors to one another.

[0044] The spacing elements may include ribs or webs.

[0045] The spacing element may be spaced apart from an outer wall of the patient interface.

[0046] The spacing element may include a concave curved surface extending between the flow directors.

[0047] The features disclosed for the first embodiment regarding the partition wall and the flow director are equally applicable to this embodiment.

[0048] In a third aspect, there is provided a non-invasive patient interface configured to seal around a patient's mouth and nostrils, the patient interface comprising: (a) an outer wall defining an interior volume of a patient interface, the outer wall having one or more oral openings in gas communication with the mouth and one or more nasal openings in gas communication with the nasal passages; (b) a partition wall separating the interior volume into a first chamber having one or more oral openings and a second chamber having one or more nostril openings; Including, The partition wall includes one or more spaced apart flow directors that allow gas to flow from the first chamber to the second chamber, the flow directors being configured to direct the gas flow through the nostril openings.

[0049] One or more spaced apart flow directors may be coupled to the outer wall.

[0050] The patient interface can include at least two flow directors spaced apart by a gap that allows breathing gas from the first chamber and exhaled breathing gas from the nares to flow into the second chamber.

[0051] Each of the one or more flow directors may have a second opening in the second chamber and a first opening that opens into the first chamber.

[0052] Each flow director may define an independent gas flow path.

[0053] One or more of the bodies of the flow directors can be coupled to the outer wall such that the gas flow passages are defined in part by the bodies and in part by the outer wall.

[0054] One or more flow directors may be coupled to the outer wall at or adjacent one or more nostril openings.

[0055] The one or more flow directors may be coupled to the outer wall laterally outwardly of the one or more nostril openings.

[0056] The one or more flow directors may be coupled to the outer wall distal to the one or more nostril openings.

[0057] The one or more flow directors may be coupled to the outer wall in the first chamber.

[0058] One or more flow directors may be coupled to the outer wall in the first chamber and in the second chamber.

[0059] The body or bodies of the flow directors may be coupled to the outer wall between the at least one or more nostril openings and the at least one or more oral openings.

[0060] The body or bodies of the flow director may be coupled to an outer wall of the one or more nostril openings opposite the wall portion.

[0061] The body of one or more of the flow directors may be coupled to the outer wall at or adjacent one or more nostril openings.

[0062] The patient interface may include at least two spaced apart flow directors, a portion of each of the flow director bodies joining the outer wall laterally outward of the lateral rims of one or more nostril openings, and another portion of each of the flow director bodies joining the outer wall laterally inward of the lateral rims of one or more nostril openings.

[0063] Each body may have an outer wall and an inner wall, both of which extend from spaced apart locations at the wall portion and abut each other at a location spaced from the wall portion.

[0064] An outer wall and an inner wall may extend from the partition wall and abut the outer wall.

[0065] The outer wall may join laterally outward of a lateral rim of the one or more nostril openings such that the rim of at least one or more nostril openings forms part of a rim of the flow director.

[0066] The inner wall may join with the outer wall laterally inward of the lateral rims of the nostril opening or openings such that a portion of the inner wall forms part of the rim of the flow director.

[0067] The rim of the second opening formed by the inner wall may be closer to the divider wall than the rim of the second opening formed by the lateral rims of one or more nostril openings.

[0068] The body may be connected to the outer wall by a connecting element.

[0069] The second opening from the one or more flow directors may be defined in part by at least one or more nostril openings.

[0070] The second opening of each flow director may be configured to direct breathing gas laterally inwardly.

[0071] Features disclosed with respect to the first embodiment are equally applicable to the second and third embodiments, and features disclosed with respect to the second embodiment are equally applicable to the third embodiment, and the application of a feature from one embodiment does not exclude the application of a feature from another embodiment.

[0072] The following disclosure applies to each of the first, second and third aspects disclosed above.

[0073] The divider wall can include one or more regions of preferential deformation that accommodate at least some deformation forces caused by patient contact with the patient engaging surface in preference to deformation of the flow director.

[0074] The flow director may be spaced apart from one or more regions of preferential deformation.

[0075] The one or more regions of preferential deformation may decouple one portion of the partition wall from another portion of the partition wall such that a force applied to one portion is greater than the force experienced by the decoupled portion.

[0076] The region of preferential deformation may decouple one portion of the partition wall from another portion of the partition wall allowing the two portions to move relative to one another.

[0077] The two parts of the partition wall can be shaped to be less prone to deformation.

[0078] The exterior wall or partition wall may include a deformation resistant section that transfers deformation forces to the preferred deformation region such that deformation of the partition wall is substantially limited to the preferred deformation region.

[0079] One or more regions of preferential deformation may be interposed between the flow director and the elastic region.

[0080] The one or more preferential deformation regions may include a first elastic region and a deformation panel disposed between the first elastic region and the flow director.

[0081] The deformation panel may have a thickness that is less than a thickness of the first elastic region.

[0082] The deformable panel may include a first wall protruding from a first elastic region and a second wall connecting the first wall to a second elastic region of the partition wall including one or more flow guides, the first and second walls abutting along a connecting line.

[0083] The first and second walls may be adapted to deform in a predetermined sequence.

[0084] The predetermined sequence can include the first wall folding towards the first elastic region.

[0085] The predetermined sequence may include the second wall buckling to accommodate a reduction in the spacing between the first elastic region and a region of the partition wall including the one or more flow directors.

[0086] The second wall may be configured to induce buckling when a distance between a region of the partition wall including the one or more flow directors and the tie line is less than a length of the second wall.

[0087] The second wall may have a curved contour from the tie line to a region of the partition wall including the one or more flow directors to induce buckling of the second wall.

[0088] The second wall may increase in thickness from the connection portion to the second elastic region to cause initial folding of the first wall and subsequent buckling of the second wall during deformation.

[0089] The deformation panel may have a wall thickness selected to induce deformation of the deformation panel in preference to the first and second elastic regions.

[0090] The first elastic region may have a thickness at least three times the thickness of the first wall.

[0091] The second wall may have a contour from the first wall to a region of the partition wall that includes one or more flow guides to induce a rolling motion in the second wall to accommodate deformations in the deformation region.

[0092] The second wall may increase in thickness from the first wall to the flow guide region to cause an initial folding of the first wall during deformation followed by a subsequent rolling of the second wall starting at the intersection between the second wall and the first wall.

[0093] An imaginary line extending from the line of intersection between the first elastic region and the first wall may meet at a pivot point with another imaginary line extending along the line of connection between the first wall and the second wall.

[0094] The first elastic region may include a first thickened region of the partition wall.

[0095] The first thickened region may include a resilient lip adjacent the deformation panel.

[0096] The deformation of the one or more preferential deformation regions may include a reduction in the spacing between the first elastic region and a region of the partition wall including the one or more flow guides, and may include an associated deformation of the deformation panel to accommodate the reduction in spacing.

[0097] The patient interface may include one or more deformation-resistant sections configured to withstand at least some deformation force applied to the patient engaging surface, the one or more flow guides being able to withstand a smaller deformation force than the deformation-resistant sections.

[0098] The one or more deformation-resistant sections can be configured to reduce the extent to which the flow director deforms due to a deformation force applied to the patient engaging surface.

[0099] The flow director or partition may include one or more deformation resistant sections.

[0100] The one or more deformation-resistant sections may increase resistance to deformation in a region of the partition wall that includes the one or more flow directors.

[0101] The divider wall may include one or more deformation resistant sections between the patient engaging surface and the preferential deformation region.

[0102] The deformation resistant section or sections may be in an area of ​​the partition wall that includes the flow director or directors.

[0103] One or more of the deformation-resistant sections may include a rib associated with the partition wall.

[0104] One or more of the deformation-resistant sections may be integrally formed with the partition wall.

[0105] One or more of the deformation-resistant sections may include a portion of the partition wall having a wall thickness that is greater than a wall thickness of other portions of the partition wall.

[0106] One or more of the deformation-resistant sections may be configured to direct a deformation force applied to the patient engaging surface towards a preferential deformation region.

[0107] One or more of the deformation resistance sections may extend from or adjacent to the patient engaging surface and may extend into a region of the partition wall that includes one or more flow guides to direct deformation forces to the preferential deformation region.

[0108] One or more of the deformation-resistant sections may be wider at an end at or adjacent to the patient engaging surface than at an end away from the patient engaging surface.

[0109] One or more of the deformation-resistant sections may include a deformation-transmitting rib formed on an underside of the partition wall.

[0110] One or more of the deformation-resistant sections may be configured to cause the flow director to conform to deformations of the patient engaging surface.

[0111] One or more of the deformation-resistant sections may be configured to overlap at least partially with the lower and upper sides of the partition wall.

[0112] One or more of the deformation-resistant sections may be located where the flow director joins the partition wall.

[0113] One or more of the deformation-resistant sections located where the flow director joins the divider wall may be coupled to the patient engaging surface.

[0114] One or more of the deformation resistant sections located where the flow director joins the divider wall may be connected to the patient engaging surface by one or more other deformation resistant sections.

[0115] One or more of the deformation resistance sections located where the flow guide joins the partition wall can reinforce the area of ​​the partition wall that includes the one or more flow guides so that at least a portion of the deformation forces applied to the patient engaging surface are transferred to the preferential deformation area.

[0116] One or more of the deformation resistance sections located where the flow guide joins with the partition wall may be located on the upper or lower side of the partition wall and may be connected to the patient engaging surface by one or more other deformation resistance sections located on the lower or upper side, respectively.

[0117] One or more of the deformation-resistant sections may overlap the spacing element such that the flow director follows movement of the one or more deformation-resistant sections that overlap the spacing element.

[0118] The spacing elements and overlapping deformation-resistant sections may extend substantially perpendicular to one another.

[0119] One or more of the deformation-resistant sections may be configured on the lower and upper sides of the partition wall to transfer deformation of the patient engaging surface to deformation of the preferential deformation region.

[0120] The deformation resistance section may be configured to at least partially overlap another of the one or more deformation resistance sections located where the flow director abuts the partition wall.

[0121] The flow director may be configured to accelerate breathing gas from the first opening to the second opening.

[0122] The second openings of the flow director may have a combined area that is less than an area of ​​the one or more nostril openings.

[0123] The second opening of the flow director may be located laterally outward of the one or more nostril openings.

[0124] Each flow director may include a body having a cross-sectional area that decreases in a direction from the inlet to the outlet.

[0125] Each flow director may comprise a body having a substantially constant cross-sectional area from the inlet to the outlet.

[0126] The body may include a lower body portion and an upper body portion, the upper body portion having a cross-sectional area smaller than the cross-sectional profile of the lower body portion.

[0127] The lower body portion may have a conical profile.

[0128] The lower body may have a contour.

[0129] The upper body portion may have a conical profile.

[0130] The upper body portion may have a circular, elliptical, or oval shape in a cross section generally parallel to the divider wall in which the flow director is located.

[0131] The body may have a conical or stepped profile in a cross section generally perpendicular to the partition in which the flow director is located.

[0132] The body may have a tapered profile in a cross section generally perpendicular to the partition wall in which the flow director is located.

[0133] The patient interface may have an inlet to the first chamber for breathing gas.

[0134] The patient interface may have an exhaust vent configured to pass respiratory gas from the patient interface to an exterior of the patient interface.

[0135] The exhaust port may be configured to pass breathing gas from the second chamber to an exterior of the patient interface.

[0136] The exhaust port may be configured to pass breathing gas from the first and second chambers to an exterior of the patient interface.

[0137] The outer wall may be provided by a cushion module comprising a resilient seal member and a housing, the seal member and housing together defining the first and second chambers.

[0138] The seal member may include a patient engaging surface.

[0139] The inlet may be formed in the housing.

[0140] The exhaust port may be formed in the housing.

[0141] A partition wall may be disposed between the inlet and the exhaust.

[0142] The dividing wall may be disposed between one or more oral openings and one or more nostril openings.

[0143] The seal member may include a nostril sealing portion that includes one or more nostril openings, and the seal member further includes a mouth sealing portion that includes one or more oral cavity openings.

[0144] The seal member may be of a resilient material and the seal member may be connected to the mask housing to form a unitary structure.

[0145] The seal member may be of a resilient material and may be mechanically locked to the mask housing to form a unitary structure.

[0146] The seal member may be overmolded onto the mask housing and mechanically locked and / or chemically bonded to the mask housing.

[0147] The patient interface may further include a mask frame.

[0148] The mask frame may be removably connectable to the mask housing.

[0149] The mask frame may be removably connectable by cooperable snap-fit ​​structures on the mask housing and on the mask frame.

[0150] The mask frame may be permanently connectable to the housing by cooperable structures on the mask housing and the mask frame.

[0151] The mask frame may be permanently connectable to the housing by ultrasonically welding the mask housing and the mask frame together.

[0152] The mask frame and the mask housing may be integrally formed.

[0153] The mask frame or mask housing may further comprise a headgear connector for connecting the headgear to the patient interface.

[0154] The patient interface may further include a conduit connector and a rotator cuff rotatably connecting the conduit connector to the mask frame to define a flow path for respiratory gas from the conduit to the first chamber.

[0155] In a fourth aspect, there is provided a non-invasive patient interface configured to seal around a patient's mouth and nostrils, the patient interface comprising: (a) an outer wall defining an interior volume including a first chamber having one or more oral openings in gas communication with the mouth, and a second chamber having one or more nasal openings in gas communication with the nasal passages; (b) a partition wall separating the first chamber from the second chamber; (c) one or more flow directors that allow gas to flow from the first chamber into the second chamber or from the second chamber into the first chamber.

[0156] The one or more flow directors are configured to allow gases to flow from the first chamber to the second chamber and to direct the flow of gases through the one or more nostril openings.

[0157] The divider wall is configured to reduce movement of the flow directors toward one another.

[0158] The divider is configured to reduce collapse of the flow director.

[0159] The divider is configured to reduce buckling of the flow director.

[0160] The dividers are configured to reduce inward collapse or buckling of the flow directors towards one another.

[0161] The partition wall includes a lateral side portion disposed laterally outward of the flow director and joining the outer wall.

[0162] The outer portion joins the outer wall at a location spaced from the top of the outer wall.

[0163] The outer portion joins the outer wall at a height below the lowest point of the nostril opening or openings, taking into account the upright orientation of the patient interface.

[0164] The outer portion is joined to the outer wall along a line which, taking into account the upright orientation of the patient interface, extends at least partially above and partially below the lowest position of the one or more nostril openings, but does not extend above the highest position of the one or more nostril openings.

[0165] A portion of the outer portion is joined to the outer wall along a line that extends between the highest and lowest positions of the one or more nostril openings and does not extend above the highest position of the one or more nostril openings, taking into account the upright orientation of the patient interface.

[0166] A portion of the outer portion is joined to the outer wall along a line that extends above the highest point of the nostril opening or openings, taking into account the upright orientation of the patient interface.

[0167] The outer portion is joined to the outer wall at a height that is lower than or substantially equal to the highest point of the flow director, taking into account the upright orientation of the patient interface.

[0168] The partition wall includes a deformation region configured to deform preferentially relative to the flow director.

[0169] The deformation region is configured to deform preferentially also at the outer portions.

[0170] The divider wall is configured to reduce lateral inward movement of the outer portion when the deformation region is deformed.

[0171] The flow director is disposed between the patient contacting portion of the outer wall and the deformation region, with the outer portion disposed laterally outward of the flow director.

[0172] The outer portion includes the portion of the deformation region that is disposed laterally outward of the flow director.

[0173] The outer portion is proximal to the deformation region.

[0174] The outer portion is joined, at least in part, to a portion of the outer wall having a wall thickness greater than a wall thickness of the patient-contacting portion of the outer wall.

[0175] The outer portion is joined, at least in part, to a portion of the outer wall having a wall thickness selected to resist deformation of the outer wall.

[0176] The outer wall comprises a housing forming at least part of the joint between the gas supply and the seal member, and the partition wall extends, at least in part, along an imaginary line that is continuous with a line extending across the top of the housing, taking into account the upright orientation of the patient interface.

[0177] Considering the upright orientation of the patient interface, the slope of the outer portion where it joins the outer wall may be horizontal or at an acute angle to the horizontal.

[0178] Considering the upright orientation of the patient interface, the inclination of the outer portion that joins the outer wall is horizontal or less than 45° to the horizontal plane.

[0179] Considering the upright orientation of the patient interface, the inclination of the outer portion which joins the outer wall is horizontal or less than 30° to the horizontal plane.

[0180] Considering the upright orientation of the patient interface, the inclination of the outer portion where it joins the outer wall is horizontal or less than 15° to the horizontal plane.

[0181] The lateral sidewall joins the outer wall at an angle that is obtuse in the second chamber.

[0182] Each flow director has a first opening to the first chamber and a second opening to the second chamber.

[0183] The first opening has a shape in which the major axis is longer than the orthogonal minor axis.

[0184] The major axis lies in the plane of the partition wall and is oriented at least 45° from a vertical mid-plane through the patient interface.

[0185] The major axes of each of the first openings intersect at a point proximal to an imaginary line passing through the center of the first openings.

[0186] The major axes of each of the first openings intersect at a point proximal to the patient-contacting portion of the outer wall.

[0187] The angle between the major axes where they intersect is less than 180°.

[0188] The angle between the major axes where they intersect is in the range of 45° to less than 180°.

[0189] The angle between the major axes where they intersect is in the range of 90° to 150°.

[0190] The angle between the major axes where they intersect is in the range of 110° to 150°.

[0191] The major axes of each of the first openings intersect at a point distal to an imaginary line passing through the center of the first openings.

[0192] The first opening is disposed between the deformation region and the patient contacting portion of the outer wall and extends a distance less than the distance between the patient contacting portion of the outer wall portion and the deformation region.

[0193] The first opening is disposed between the deformation region and a patient-contacting portion of the outer wall between the one or more nostril openings and the one or more oral openings, and extends over a distance that is less than the distance between the patient-contacting portion of the outer wall portion and the deformation region.

[0194] The first opening is disposed in the partition wall.

[0195] The flow guider defining each of the first openings is spaced apart from the deformation region.

[0196] Each of the first openings has an elliptical shape.

[0197] The orientation of the major and minor axes is maintained through the flow director.

[0198] The dimension of the major or minor axis, or both the major and minor axes, of the second opening is different than the dimension of the major or minor axis, or both the major and minor axes, of the first opening.

[0199] The major or minor axis or both the major and minor dimensions of the second opening are smaller than the major or minor axis or both the major and minor dimensions of the first opening.

[0200] The major or minor axis, or both the major and minor axis dimensions vary throughout the flow director.

[0201] The dimension of the major or minor axis, or both the major and minor axes, decreases from the first opening to the second opening.

[0202] The dimensions of the major or minor axis, or both the major and minor axes, vary to define a constriction.

[0203] The second opening of each flow guide is spaced apart from the outer wall to allow gas flow between the first and second chambers, and the second opening is positioned such that a gas stream flowing from the first chamber through the flow guide to the second chamber at least partially impinges on the outer wall when the patient interface is not attached to a patient.

[0204] When the patient interface is attached to the patient, the area, shape, or shape and area of ​​the nostril openings changes.

[0205] When the patient interface is attached to a patient, the area, shape, or shape and area of ​​the one or more nostril openings changes such that a gas stream passing through the flow director is directed through the one or more nostril openings without impinging on the outer wall.

[0206] The flow director and the outer wall are positioned such that the outer wall extends over a portion of each second opening when the patient interface is not attached.

[0207] The outer wall extends over a portion of the second openings when viewed vertically above a midpoint between the second openings, taking into account an upright orientation of the patient interface when the patient interface is not attached to a patient.

[0208] The portion of the second opening over which the outer wall extends is the laterally outer portion of the second opening.

[0209] At least a portion of each second opening is outside of an imaginary cylindrical volume having the contour of and extending vertically through the one or more nostril openings, taking into account an upright orientation of the patient interface when the patient interface is not attached to a patient.

[0210] At least a portion of each second opening is obscured by the outer wall when the patient interface is viewed vertically above a midpoint between the second openings, taking into account an upright orientation of the patient interface when the patient interface is not attached to a patient.

[0211] When the patient interface is attached to a patient, a lateral outer edge of the one or more nostril openings is disposed laterally outward of the second opening of the respective flow director.

[0212] The outer wall is configured to allow one or more nostril openings to flare laterally outward.

[0213] The outer wall is configured to allow one or more nostril openings to flare laterally outward such that, when the patient interface is viewed vertically above a midpoint between the second openings, the outer wall does not extend over a portion of each second opening, taking into account an upright orientation of the patient interface when attached to a patient.

[0214] The patient contacting surface of the outer wall is configured to allow the outer wall extending over the second opening of the flow guide to move laterally outward such that the outer wall no longer extends over the second opening when the patient interface is attached to a patient.

[0215] The patient contacting surface is curved to receive the underside of the patient's nose when the patient interface is attached to the patient, and the curvature decreases when the patient interface is attached.

[0216] The patient contacting surface includes a valley shape configured to receive the underside of the patient's nose, and a floor of the valley shape including the one or more nostril openings assumes a flatter valley shape when the patient interface is attached to the patient.

[0217] The partition wall includes flow guides that allow gas flow between the first and second chambers, each flow guide having a base that joins the partition wall and defines a first opening from the first chamber, a body extending from the base, a rim spaced from the base and defining a second opening that opens into the second chamber, and a gas flow channel extending from the first opening in the base to the second opening.

[0218] The body includes reinforcing segments configured to resist deformation of the shape of the outlet under a deforming force.

[0219] The reinforcing segments may extend completely or partially around the body.

[0220] The reinforcing segment has a wall thickness that is greater than the wall thickness of the remainder of the body.

[0221] The reinforcing segment includes a rib.

[0222] The body is formed from a first material and the reinforcing segments are formed from a second material that is different from and less compliant than the first material.

[0223] The reinforcing segment extends around at least a portion of the distal side of the body.

[0224] The reinforcing segment is located to one side of a major axis of the flow director profile that is generally parallel to the partition wall.

[0225] The reinforcing segments are positioned about the body at set intervals from the rim.

[0226] The reinforcing segments are disposed about the body at set intervals from the base.

[0227] The reinforcing segments are positioned about the body at varying distances from the rim.

[0228] The reinforcing segment is disposed adjacent the rim.

[0229] The reinforcing segments are disposed on the exterior of the body.

[0230] The body includes a lower body portion and an upper body portion.

[0231] The reinforcing segment extends completely or partially around the lower body portion.

[0232] The reinforcing segment extends completely or partially around the upper body portion.

[0233] The reinforcing segment extends from the lower body portion and at least partially around the upper body portion.

[0234] The upper body portion has a wall thickness that is less than the wall thickness of the lower body portion.

[0235] The base of each flow director is elongated laterally away from a vertical midplane through the patient interface, taking into account the upright orientation of the patient interface, and the body is offset from a lateral centerline through the base such that it is closer to the lateral inward side of the base than to the lateral outward side of the base.

[0236] The laterally outer side of the base extends laterally outwardly further from the body than the laterally inner side of the base extends laterally inwardly from the body.

[0237] The laterally outer side of the base extends laterally outwardly from the body at least two times, at least three times, at least four times, or at least five times further than the laterally inner side of the base extends laterally inwardly from the body.

[0238] The base has a footprint that extends laterally beyond corresponding side edges of one or more nostril openings.

[0239] The gas flow path has a longitudinal axis that is offset laterally inward from a lateral centerline through the base that is parallel to a vertical midplane through the patient interface such that the gas flow channel is closer to the laterally inner side of the base than to the laterally outer side of the base.

[0240] The base has a wall thickness that is greater than the wall thickness of the partition wall adjacent the base.

[0241] The base includes a thickened pad extending laterally outwardly of the body.

[0242] The thickened pad has a wall thickness that decreases away from the body.

[0243] The thickened pad has a wedge-shaped profile in the lateral outward direction.

[0244] The base at least partially covers the body.

[0245] The base includes lateral outer sides configured to resist displacement of the outlets toward one another.

[0246] The lateral outer side of the base is configured as a stiffening link between the partition and the body, thus resisting bending of the partition which causes displacement and orientation changes of the body.

[0247] The lateral exterior of the base tapers from the partition wall to the body.

[0248] The laterally outward taper of the base has a fillet portion.

[0249] The laterally outer side of the base includes a radial wall thickness, taken along the longitudinal axis of the gas flow channel, that is greater than the radial wall thickness at any point in the remainder of the body.

[0250] The base of each flow director comprises a block containing the gas flow channels and having a thickness to resist deformation of the body.

[0251] The base is configured to resist displacement and changes in orientation of the body by transmitting a deformation force applied to the outer wall to the deformation region.

[0252] The bases of the flow directors are connected to one another to form a common block from which the separate bodies extend.

[0253] The common block has a footprint that extends laterally beyond the corresponding side edges of one or more nostril openings.

[0254] The common block has an angled side extending from an outer portion of the partition wall to the body.

[0255] The area of ​​the common block that is constrained by the angled sides tapers downwardly in the distal direction.

[0256] This region is tapered to be substantially parallel to the nostril opening or openings.

[0257] The angled sides of the common block have a fillet shape.

[0258] The fillet shape is continuous around the lateral side of the common block.

[0259] The fillet shape is continuous around the proximal and distal sides of the common block.

[0260] The fillet shape includes spaced apart portions and is continuous around the proximal and distal sides of the common block.

[0261] The wall thickness of the flow director decreases from the base to the rim.

[0262] The body includes a transition portion intermediate the base and the rim.

[0263] A transition section delineates the lower body portion from the upper body portion.

[0264] The upper body portion includes a wall thickness that is less than the wall thickness of the lower body portion.

[0265] The wall thickness of the lower body portion is constant and the wall thickness of the upper body portion decreases from the transition to the rim.

[0266] The wall thickness of the body varies from the transition to the rim.

[0267] The wall thickness of the body decreases from the transition to the rim.

[0268] The reduction in wall thickness of the body from the transition to the rim is constant.

[0269] The reduction in wall thickness of the body from the transition to the rim is not constant.

[0270] The transition portion is inclined relative to the partition wall.

[0271] The transition is tapered such that the distal side of the lower body portion extends further from the base than the proximal side of the lower body portion extends from the base.

[0272] The plane defined by the transition portion is generally parallel to the one or more nostril openings, or the upper outer wall of the flow director, or the one or more nostril openings and the upper outer wall of the flow director, taking into account the upright orientation of the patient interface.

[0273] The rim of the upper body portion is generally parallel to the one or more nostril openings, or the upper outer wall of the flow director, or the one or more nostril openings and the upper outer wall of the flow director, taking into account the upright orientation of the patient interface.

[0274] The lower body portion has a wall thickness selected to resist deformation more than the deformation region resists deformation, such that the deformation region preferentially deforms in response to deformation forces applied to the patient-contacting portion of the seal member.

[0275] The distal outer surface of the flow director has a curvilinear profile in the direction of the longitudinal axis of the flow director.

[0276] The reduction in wall thickness of the flow director from the transition to the rim is due to the outer surface of the flow director tapering inwardly towards the inner surface of the flow director.

[0277] The transition portion includes, at least in part, a step intermediate the base and the rim.

[0278] The body below the step has a first wall thickness and the body above the step has a second wall thickness, the second wall thickness being less than the first wall thickness.

[0279] The step extends around at least a distal side of the flow director.

[0280] The step extends around the distal and laterally outer side of the flow director.

[0281] The step extends substantially all the way around the flow director.

[0282] The step extends completely around the flow director.

[0283] The step includes a sloped surface connecting the lower body portion to the upper body portion.

[0284] The step is formed on the outer side of the flow guide.

[0285] Considering the longitudinal axis of the flow director, the radial wall thickness of the lower body portion varies around the periphery of the flow director.

[0286] Considering the longitudinal axis of the flow director, the radial wall thickness of the lower body portion varies with the spacing of the rim from the base.

[0287] Considering the longitudinal axis of the flow director, the radial wall thickness of the lower body portion is greater at a greater distance from the base of the rim than at a lesser distance from the base of the rim.

[0288] Considering the longitudinal axis of the flow director, the radial wall thickness of the lower body portion is smallest where the spacing between the rim and the base is smallest and increases as the spacing between the rim and the base increases.

[0289] The radial wall thickness of the lower body portion is constant around the flow director.

[0290] The radial wall thickness of the upper body portion is constant around the flow director.

[0291] The divider wall includes spacer ribs disposed between the bodies of the flow directors.

[0292] The spacer rib joins the body at a location spaced from the rim.

[0293] The spacer rib joins the base and body of the flow director to a location spaced from the rim.

[0294] The spacer ribs only interface with the base and lower body portions of the flow director.

[0295] The flow director includes a step between the lower body portion and the upper body portion and a spacer rib joining the step.

[0296] The spacer rib has a flattened upper surface which interfaces with the step.

[0297] The spacer ribs only interface with the base and lower body portions and steps of the flow director.

[0298] The spacer rib includes a fillet shaped transition joint with the flow director.

[0299] The spacer ribs are disposed in a plane that intersects the longitudinal axis of the flow director.

[0300] The spacer rib has a wall thickness in the distal-proximal direction that is 5-20% of the dimension of the flow director in the distal-proximal direction.

[0301] The spacer rib has a wall thickness in the distal-proximal direction that is 20-40% of the dimension of the flow director in the distal-proximal direction.

[0302] The spacer rib has a wall thickness in the distal-proximal direction that is 40-60% of the dimension of the flow director in the distal-proximal direction.

[0303] The spacer ribs overlap reinforcing sections of the partition wall positioned to transfer deformation forces applied to the patient-contacting portion of the outer wall to the deformation area.

[0304] The divider wall includes a respective brace member disposed between each flow director and the outer wall, the brace member maintaining a spacing between the outer wall and each flow director.

[0305] Each brace member joins the exterior wall at a portion of the exterior wall between one or more nostril openings and one or more oral openings.

[0306] Each brace member is joined only to the exterior wall portion and to the lower body portion.

[0307] Each brace member interfaces only with the outer wall portion and with the lower body portion and step portion.

[0308] Each brace member interfaces with an exterior wall portion and with a common block.

[0309] Each brace member interfaces with an outer wall portion and with a respective block of the flow director.

[0310] The width of each brace member is 20 to 70% of the width of the flow guide portion.

[0311] The brace member has a polygonal profile.

[0312] The brace member has a trapezoidal profile.

[0313] The brace member has a semicircular profile.

[0314] The brace member has a contour that is a circle segment.

[0315] The brace member has a curved profile.

[0316] A proximal portion of the partition between the spacer rib and the wall portion of the seal and the outer portion of the partition may have a wall thickness that is greater than the wall thickness of the outer portion of the partition.

[0317] The wall thickness of the proximal portion may be at least 1.5 times the wall thickness of the outer portion.

[0318] The wall thickness of the proximal portion may be in the range of 1.5 to 8 times the wall thickness of the outer portion.

[0319] The wall thickness of the proximal portion may be in the range of 1.5 to 3 times the wall thickness of the outer portion.

[0320] The wall thickness of the proximal portion may be greater than the wall thickness of a distal portion of the partition between the spacer rib and the deformation panel and between the outer portion of the partition.

[0321] The wall thickness of the proximal portion may be different at different locations. The wall thickness of the proximal portion may vary across the proximal portion in the proximal-distal direction or laterally, or in both directions.

[0322] The spacer rib may be positioned distally from the center of the second opening of the flow director.

[0323] The spacer rib may be aligned in a proximal-distal direction with a distal portion of the rim that defines the second opening.

[0324] The main portion of the partition wall may have a curved profile in the proximal-distal direction.

[0325] The curvilinear profile may extend across substantially the entire lateral dimension of the main portion of the partition wall.

[0326] The curved contour may extend through the proximal and distal portions of the partition wall.

[0327] The contour may be concave in the proximal-distal direction and relative to the nostril opening.

[0328] The proximal and distal portions may have sloped profiles relative to one another in the proximal-distal direction such that the angle between them on the side of the partition wall in the second chamber is less than 180°.

[0329] The contour of the proximal portion may be curvilinear.

[0330] The contour of the distal portion may be curvilinear.

[0331] The contour of the proximal portion may be concave relative to the nostril opening.

[0332] The contour of the distal portion may be concave relative to the nostril opening.

[0333] A distal portion of the partition between the spacer ribs and the deformation region and the outer portion of the partition may have a wall thickness that is greater than the wall thickness of the outer portion of the partition.

[0334] The wall thickness of the distal portion may be at least 1.5 times the wall thickness of the outer portion.

[0335] The wall thickness of the distal portion may be in the range of 1.5 to 8 times the wall thickness of the outer portion.

[0336] The wall thickness of the distal portion may be in the range of 1.5 to 3 times the wall thickness of the outer portion.

[0337] The wall thickness of the distal portion may vary in the proximal-distal direction.

[0338] The wall thickness of the distal portion may vary laterally.

[0339] The wall thickness of the distal portion may be the same as the wall thickness of the proximal portion.

[0340] The wall thickness of the distal portion may be greater than the wall thickness of the proximal portion.

[0341] The distal portion may include one or more tapered regions in which the wall thickness of the distal portion decreases in the direction of the adjacent outer portion or in the direction of the adjacent deformed panel to the same thickness as the respective adjacent outer portion or adjacent deformed panel.

[0342] One or more of the tapered regions may be located on a side of the partition wall facing the first chamber.

[0343] One or more of the tapered regions may be located on a side of the partition wall facing the second chamber.

[0344] One or more of the tapered regions can be located on a side of the partition wall facing the second chamber, and one or more of the tapered regions can be located on a side of the partition wall facing the first chamber.

[0345] The spacer rib may include a tapered region disposed between the proximal and distal portions.

[0346] The or each flow director's base may include a tapered region in which the wall thickness of the distal portion reduces to a thickness that matches the wall thickness of the body portion of the one or more flow directors.

[0347] The distal portion may have a lateral width that tapers inwardly in the distal direction.

[0348] The patient interface may include a tether between the body and the divider wall of each flow director.

[0349] The tethers can be configured to resist changes in orientation between the body and the divider wall of each flow director.

[0350] A tether may connect the body to the distal portion at a location on the body and on the distal portion spaced from the base of each flow director.

[0351] The tether can join the flow director along the body and the base, and join the distal portion from the base to a location spaced from the base.

[0352] The tethers may be ribs extending between the body and the distal portion of each flow director.

[0353] The tether can be positioned distal to the flow director.

[0354] The tether can be oriented in a proximal-distal direction.

[0355] The tether can be an extension of the body in a distal direction, the extension having a wall thickness in the proximal-distal direction that is greater than the wall thickness of the remainder of the body.

[0356] The extension may taper distally inwardly in a cross section parallel to the plane of the distal portion.

[0357] The patient interface may include one or more tethers connecting the deforming panel to the first elastic region.

[0358] The deformation panel can extend from the first elastic region to define a gap into which the main portion moves when the deformation panel is deformed, and the, or each respective, tether extends across the gap and joins the first elastic region and the deformation panel.

[0359] A gap may be formed between the main portion and the first elastic region.

[0360] The, or each, tether may be configured to resist movement of the distal portion towards the nostril seal of the outer wall.

[0361] The, or each respective tether may be configured to limit movement of the divider wall away from the first elastic region.

[0362] The or each respective tether may be a panel that connects the deformation panel and the first elastic region.

[0363] The panels can be configured to collapse under compression and are configured to resist elongation under tension.

[0364] The panels can be configured to collapse under compression in the proximal-distal direction and are configured to resist stretching under tension in the proximal-distal direction and / or toward the nostril seals.

[0365] The panel may have a wall thickness that is the same as the wall thickness of the first wall of the deformed panel.

[0366] The panel may have a wall thickness that is less than a wall thickness of the first wall of the deformed panel.

[0367] The or each tether may be perpendicular to the first wall of the modified panel.

[0368] The or each respective tether may connect the distal portion and the first elastic region.

[0369] The or each respective tether may join the distal portion, the deformation panel, and the first elastic region.

[0370] The or each respective tether may connect the first elastic region and the reinforced section associated with the distal portion.

[0371] The or each respective tether may connect the deformation panel and the first elastic region.

[0372] The tether may include a free edge exposed to the oral cavity.

[0373] The free edge may be a straight line extending between the first elastic region and the deformation panel or the distal portion, or a reinforcement section associated with the distal portion.

[0374] The or each respective tether may include a weak point at which collapse of the tether may be induced under compressive forces.

[0375] The or each respective tether may include a point of weakness such that when the distal portion moves toward the first elastic region, collapse of the tether at the point of weakness is induced.

[0376] The point of weakness may be a reduction in the wall thickness of the or each respective tie.

[0377] The free edge may extend between the first elastic region and the deformation panel or the distal portion, or a reinforcing rib associated with the distal portion, the free edge including the point of weakness.

[0378] The weakened point of the free edge may be a notch located between the deformation panel and the first elastic region.

[0379] The notch has a V-shape.

[0380] The patient interface can include two tethers, each tether aligned with the distal portion in the proximal-distal direction.

[0381] The patient interface can include two tethers, each tether aligned with a respective outer portion in the proximal-distal direction.

[0382] The two tethers may be parallel to one another in the proximal-distal direction.

[0383] The two tethers may move away from each other in a distal direction.

[0384] The two tethers may converge towards each other in the distal direction.

[0385] A free edge of the, or each respective tether may extend to the respective flow director.

[0386] A free edge of the, or each respective tether may be integral with a respective flow director.

[0387] The free edges may be integral with the base of each flow director.

[0388] The divider wall may include a reinforcing structure extending across at least a distal portion of the divider wall and adjacent the deformation panel.

[0389] The reinforcing structure may extend across the distal and outer portions of the divider wall and is adjacent the deformation panel.

[0390] The reinforcing structure can be configured to resist deformation of the distal portion and the outer portion.

[0391] The reinforcing structure may be a lateral reinforcing rib extending across the distal and outer portions at a location distal to the or each flow director.

[0392] The reinforcing structure may be spaced apart between the reinforcing structure and the deforming panel, the spacing being constant along the reinforcing structure.

[0393] The spacing may vary along the reinforcing structure.

[0394] The spacing between the reinforcement structure and the deflection panel may be greater over the distal portion than the spacing between the reinforcement structure and the deflection panel over the lateral portion.

[0395] The spacing between the reinforcing structure and the deforming panel may decrease laterally.

[0396] The spacing between the reinforcing structure and the deforming panel may be greatest at a central location.

[0397] The lateral stiffening ribs may be on the side of the partition exposed to the second chamber or on the side of the partition exposed to the first chamber.

[0398] The reinforcing structure may include a first lateral reinforcing rib on a side of the partition wall exposed to the second chamber and includes a second lateral reinforcing rib on a side of the partition wall exposed to the first chamber.

[0399] The first and second reinforcing ribs may be aligned on each side of the divider wall in a proximal-distal direction.

[0400] The first and second reinforcing ribs may be offset on each side of the divider wall in the proximal-distal direction.

[0401] The spacing from the deformation panel for the first reinforcing rib may be different from the spacing from the deformation panel for the second reinforcing rib.

[0402] The spacing from the deformed panel for the first reinforcing rib may be constant and the spacing from the deformed panel for the second reinforcing rib varies.

[0403] The spacing from the deformed panel for the second reinforcing rib may be constant and the spacing from the deformed panel for the first reinforcing rib varies.

[0404] The lateral stiffening ribs may have a consistent profile along the length of the lateral stiffening rib.

[0405] The lateral stiffening ribs may have a profile that varies along the length of the lateral stiffening rib.

[0406] The lateral stiffening ribs may have a shape that tapers in height laterally above the partition wall.

[0407] The lateral stiffening ribs may be spaced apart from the or each respective flow director.

[0408] A lateral stiffening rib may be connected to the or each respective flow director.

[0409] The patient interface may include one or more deformation region tethers within the first chamber and connecting the distal portion to the outer wall.

[0410] The deformation zone tether or tethers may be configured to inhibit inversion of the partition wall.

[0411] The or each respective deformation region tether may extend between a side of the partition wall exposed to the first chamber and an outer wall of the seal member.

[0412] The or each respective deformation region tether may extend from the outer wall to the distal portion.

[0413] The or each respective deformation area tether may connect with a partition wall between the deformation panel and the flow director or a respective one of the flow directors.

[0414] The or each deformation area tether may be spaced apart from the deformation panel.

[0415] The or each respective deformation region tether may be spaced apart from the flow director.

[0416] The or each respective deformation area tether may connect with a partition wall between the flow director and the deformation panel.

[0417] Each respective deformation region tether may be integral with a respective one of the flow directors.

[0418] The or each respective deformation zone tether may extend from the partition wall and the outer wall and have a free edge within the first chamber.

[0419] The free edge of the or each deformation zone tie may be straight.

[0420] The or each respective deformation zone tether may have a flat, planar structure.

[0421] The interface can include two deformation region tethers, with an angle between the proximal faces of each respective proximal deformation region tether being greater than 140°.

[0422] The angle between the proximal faces of each respective deformation region tether on the proximal side may be greater than 160°.

[0423] The two deformation region tethers may extend to spaced apart locations on the distal portion.

[0424] The two deformation region tethers may extend to the same location on the distal portion.

[0425] The two deformation region tethers may extend towards each other at the distal portions.

[0426] The two deformation zone ties may extend to the reinforcement section.

[0427] The or each respective deformation zone tether may include a first portion that connects with the exterior wall and a second portion that extends to and connects with the main portion.

[0428] The or each respective deformation area tether may have two connection points, one with the main portion and the other with the outer wall at a height below the distal portion, taking into account the upright orientation of the patient interface.

[0429] The or each respective deformation region tether may be a cord or wire or cable.

[0430] The first portion may have a flat planar structure and the second portion may be curved proximally such that the angle between tangents at each location along which the second portion extends is between 140° and 180°.

[0431] The or each respective deformation region tether may extend to a height below the lowest point of the divider wall, having regard to the upright orientation of the patient interface.

[0432] The, or each respective deformation region tether may extend to a height below the highest point of the oral opening, having regard to the upright orientation of the patient interface.

[0433] The deformation region tether may extend from the distal portion to the outer wall at a location distal to the proximal-most portion of the nostril opening or openings.

[0434] The free edge may extend from the outer wall at a location distal to the reinforced section.

[0435] The free edge may extend from the outer wall at a location distal to the one or more oral openings.

[0436] The free edge may extend from the outer wall at a location distal to the spacing element.

[0437] The deformation zone tethers can be configured to permit movement of the main portion of the partition wall in a proximal-distal direction and inhibit inversion of the partition wall.

[0438] The flow directors can be configured such that the gas flow rate through one flow director is greater than the gas flow rate through another flow director.

[0439] One of the respective flow guides can be configured to have a first resistance to gas flow and another of the respective flow guides can be configured to have a second resistance to gas flow, the first resistance to gas flow being lower than the second resistance to gas flow.

[0440] The first opening or the second opening, or both the first opening and the second opening, of one of the respective flow guides may be larger than the first opening or the second opening, or both the first opening and the second opening, of another of the respective flow guides.

[0441] The ratio of the area of ​​the first opening of one of the respective flow guides to the area of ​​the first opening of another of the respective flow guides may be in the range of 1:1 to 1:0.1.

[0442] The ratio of the area of ​​the second opening of one of the respective flow guides to the area of ​​the second opening of another of the respective flow guides may be in the range of 1:1 to 1:0.1.

[0443] A ratio of an area of ​​the second opening of one of the respective flow directors to an area of ​​the second opening of another of the respective flow directors may be 1:0.33.

[0444] The ratio of the area of ​​the second opening of one of the respective flow guides to the area of ​​the second opening of another of the respective flow guides may be in the range of 1:0.5 to 1:0.2.

[0445] The ratio of the combined area of ​​the first opening and the second opening of one of the flow guides to the combined area of ​​the first opening and the second opening of another of the flow guides may be in the range of 1:1 to 1:0.1.

[0446] The patient interface may include only one flow director.

[0447] One flow director may be configured to deliver a flow of breathing gas to one nostril.

[0448] One flow director can be configured to deliver an accelerated flow of breathing gas to generate the flushing flow.

[0449] One flow director can be configured to enable flushing of dead space within the nasal cavity by delivering a flushing flow to one nostril.

[0450] The flow director can be in the form of any one of the flow directors disclosed above.

[0451] The flow director may be configured to direct the flow of gas through the nostril opening and towards one of the patient's nares.

[0452] The second opening of the flow director may be laterally offset from a mid-plane through the patient interface.

[0453] The second opening of the flow director may be spaced laterally from a mid-plane through the patient interface.

[0454] The first opening of the flow director may be laterally offset from a mid-plane through the patient interface.

[0455] The first opening of the flow director may be spaced laterally from a mid-plane through the patient interface.

[0456] The partition wall opposite the midplane can include a first lateral portion adjacent the midplane, the first lateral portion having a first wall thickness and including a second lateral portion extending laterally outward from the first lateral portion, the second lateral portion having a second wall thickness, the first wall thickness being greater than the second wall thickness.

[0457] The transition between the first and second lateral portions may be spaced laterally from the mid-plane by substantially the same distance as the laterally-most positioned portion of the flow guide is spaced from the mid-plane.

[0458] The transition between the first and second lateral portions may be spaced laterally from the mid-plane by a distance greater than the distance that the outermost positioned portion of the flow guide is spaced from the mid-plane.

[0459] The transition between the first and second lateral portions may be spaced laterally from the mid-plane by a distance less than the distance that the outermost positioned portion of the flow guide is spaced from the mid-plane.

[0460] The patient interface may include one or more nostril openings that seal around the patient's nares, and includes a channel extending from the first chamber to the nostril opening, or to one of the nostril openings, the channel configured to align with one of the patient's nares, and a remainder of the one nostril opening, or another of the nostril openings, configured to align with the other of the patient's nares.

[0461] The channel can be configured to allow gases from the other of the patient's nostril to flow into the second chamber.

[0462] The channel may be configured to allow gas from the channel to flow into the second chamber.

[0463] The channel may be configured to deliver a flow of gas to only one of the patient's nostrils.

[0464] The channels may be configured to deliver a flow of gas to both of the patient's nostrils.

[0465] The channels may be configured to deliver first and second flows of gas to respective nostrils of the patient, the first and second flows of gas being unequal.

[0466] The first gas flow rate may be greater than the second gas flow rate.

[0467] The channel may be defined in part by a peripheral wall extending between the partition wall and the nostril opening or to one of the nostril openings, and in part by a partition extending between the partition wall and a recessed position from the nostril opening.

[0468] A recessed position of the partition from the nostril openings may allow gases from the channel to flow into the second chamber when the patient interface is attached to a patient.

[0469] The cross-sectional area of ​​the channel may be reduced from the divider wall to the nostril opening, or to one of the nostril openings, to accelerate the gas passing through the channel.

[0470] The channel may taper from the divider wall to the nostril opening, or to one of the nostril openings, to accelerate gas passing through the channel.

[0471] The channel profile is constant from the partition wall to the nostril opening or to one of the nostril openings.

[0472] The channel and one or more nostril openings can be configured to deliver a flushing flow of gas to the first nostril when the interface is attached to a patient, which flushing flow causes flushing of the nasal cavity such that gas flushed through the nasal cavity flows through the other nostril, through a remainder of one nostril opening or through another of the nostril openings and into the second chamber.

[0473] Each deformation zone tie may be a panel having a wall thickness that decreases from the partition wall to the free edge.

[0474] The or each respective flow guide may include a base, a lower body portion, a rim forming a second opening that opens into the second chamber, and a transition portion extending between the lower body portion and the rim.

[0475] The lower body portion can have a wall thickness, the rim has another wall thickness that is less than the wall thickness of the lower body portion, and the transition portion includes a tapered wall thickness.

[0476] The spacer rib may join the lower body portion and the transition portion at a location spaced from the rim.

[0477] The spacer rib may be located distal to an imaginary line connecting the centers of the second openings of each of the flow directors.

[0478] A base or lower body portion of the flow director or directors may be joined to the wall portion.

[0479] An inner wall of the flow director can taper inwardly towards the second opening to form an inwardly tapered channel between the first and second openings.

[0480] The wall thickness of the rim may be greater than the wall thickness of the outer, distal or proximal portion of the partition wall.

[0481] The patient interface may include: (a) one or more deformation zone ties extending between a side of the partition wall exposed to the first chamber and an outer wall of the seal member; (b) the main portion of the partition wall has a concave contour in a proximal-distal direction relative to the nostril opening; (c) the, or each, flow guide comprises a base, a lower body portion, a rim forming a second opening opening into the second chamber, and a transition portion extending between the lower body portion and the rim.

[0482] Throughout the above disclosure, the following description and claims, the terms "proximal" and "distal" and grammatical variations thereof refer to the respective proximal and distal directions. Proximal references indicate a direction toward the patient as the patient interface would be attached to the patient. Distal references indicate a direction away from the patient as the patient interface would be attached to the patient. These directions are shown in Figures 4, 34 and 40. The same orientations apply to all of the drawings and all of the embodiments disclosed herein. Use of the terms "proximal" and "distal" should not be construed as referring to a patient interface being attached to a patient unless the context dictates otherwise.

[0483] The flow director of the fourth aspect may include any one or more of the features of the flow director outlined with respect to the first, second and third aspects. The flow director of the fourth aspect may also be combined with the cushioning module disclosed above with respect to the first, second and third aspects. The following description includes the embodiments of the first, second, third and fourth aspects disclosed above. It will be understood that the embodiments of the flow director related to the fourth aspect may be combined with the embodiments of the cushioning module related to the first, second and third aspects. Furthermore, the flow director of the fourth aspect may include any one or more of the features of the flow director outlined with respect to the first, second and third aspects. The same is true for all other features described in the following description, i.e. an embodiment related to one of the aspects disclosed above described below may be combined with any of the other embodiments described below with respect to the same or different aspects disclosed above.

[0484] Throughout the above disclosure, the following description and the claims, the term "chamber" is intended to mean a patient interface structure that encloses a volume, the structure having one or more breathing gas inlets and one or more breathing gas outlets.

[0485] Throughout the disclosure above, the following description and the claims, the term "upright orientation" shall mean the orientation of the patient interface when the midplane between the outer portions of the patient interface is oriented vertically and when the distal-most points of the wall portions on the midplane are aligned vertically with the suboral point of the oral opening on the midplane. The midplane is the plane of section line AA in Figure 1 and also the plane of section line UU in Figure 30.

[0486] Although various features are disclosed above in connection with one or more aspects, it will be understood that one or more features of one aspect can be combined with other aspects to arrive at additional embodiments. As a result, the disclosure of features in the preceding description should not be construed as meaning that the features are limited in application with respect to the aspect(s) for which they are disclosed. For example, the deformation region may be incorporated into the patient interface of any of the aspects described above. As a further example, the housing disclosed above may be incorporated into the patient interface of any one of the preceding aspects.

[0487] The ordinal references (e.g., first, second, third) to the above disclosed aspects merely serve to distinguish the aspects from one another and should not be construed as an order of importance of those aspects.

[0488] Aspects of the above disclosed patient interface will now be described in detail with reference to embodiments which serve as examples only and with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0489] [Figure 1] FIG. 1 illustrates a perspective view of a patient interface and gas conduit connector according to one embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the patient interface and gas conduit connector of FIG. 1; [Diagram 3] FIG. 2 is a rear view of the patient interface and gas conduit connector of FIG. 1. [Figure 4]2 is a side cross-sectional view of the patient interface and gas conduit connector taken along line AA of FIG. 1. [Diagram 5] 5 is a cross-sectional view of the gas conduit connector taken along line BB in FIG. 4. [Figure 6] FIG. 2 is a front plan view of a housing forming part of the patient interface of FIG. 1. [Figure 7] FIG. 2 is a front perspective view of a cushion module of the patient interface of FIG. 1. [Figure 8] FIG. 8 is a perspective side cross-sectional view of only the cushion module of the patient interface taken along line CC of FIG. 7. [Figure 9] 9 is an enlarged view of a region marked D in the cross-sectional view of FIG. 8. FIG. [Figure 10] 8 is a perspective cross-sectional view of the cushion module taken along line EE in FIG. 7. [Figure 11] FIG. 8 is a cross-sectional view of the cushion module taken along line FF in FIG. 7. [Figure 12] FIG. 13 is a perspective rear view of an alternative cushion module. [Figure 13] FIG. 13 is a side cross-sectional view taken along line GG in FIG. 12. [Figure 14] 14 is an enlarged perspective view of a region marked H in the cross-sectional view of FIG. 13. [Figure 15] 13 is a bottom view of the partition wall in the cushion module of FIG. 12. FIG. [Figure 16] FIG. 13 is a perspective rear view of a further alternative cushion module. [Figure 17] FIG. 17 is a side cross-sectional view of the cushion module of FIG. 16 taken along line JJ. [Figure 18] 18 is an enlarged perspective view of a region marked K in the cross-sectional view of FIG. 17. [Figure 19] 17 is another cross-sectional side view of the cushion module of FIG. 16 taken along line LL. [Figure 20] FIG. 17 is a front cross-sectional view of the cushion module of FIG. 16 taken along line MM. [Figure 21] FIG. 17 is a bottom view of the partition wall in the cushion module of FIG. 16. [Figure 22] 22 is an enlarged perspective view of the lower side of the partition wall in the direction indicated by N in FIG. 21. [Diagram 23] FIG. 17 is a top cross-sectional view of the cushion module of FIG. 16 taken along line PP. [Figure 24] FIG. 13 is a perspective rear view of a further alternative cushion module. [Diagram 25] FIG. 25 is a top cross-sectional view of the cushion module of FIG. 24 taken along line QQ. [Figure 26] 25 is a side cross-sectional view of the cushion module of FIG. 24 taken along line RR. [Figure 27] FIG. 27 is an enlarged perspective view of a region marked S in the cross-sectional view of FIG. 26. [Figure 28] FIG. 25 is a bottom view of the partition wall in the cushion module of FIG. 24. [Figure 29] 22 is an enlarged perspective view of the lower surface of the partition wall in the direction marked with "T" in FIG. 21. [Diagram 30] FIG. 13 is a front plan view of a further alternative cushion module. [Diagram 31] FIG. 31 is a side plan view of the alternative cushion module shown in FIG. 30. [Diagram 32] FIG. 31 is a top plan view of the alternative cushion module shown in FIG. 30. [Diagram 33] FIG. 31 is a rear plan view of the alternative cushion module shown in FIG. 30. [Diagram 34] 31 is a cross-sectional view taken along line UU in FIG. 30. [Diagram 35] 35 is an enlarged view of a region marked W in the cross-sectional view of FIG. 34. [Diagram 36] FIG. 33 is an enlarged cross-sectional view taken along line XX in FIG. 32. [Figure 37] FIG. 31 is a perspective cross-sectional view taken along line YY in FIG. 30. [Figure 38] FIG. 31 is a perspective cross-sectional view taken along line ZZ in FIG. 30. [Figure 39] FIG. 31 is a cross-sectional view taken along line AA-AA in FIG. 30. [Diagram 40] FIG. 31 is a bottom view of a cross section taken along line BB-BB in FIG. [Diagram 41] 31 is an enlarged cross-sectional view of the cushion module of FIG. 30 taken along line UU with alternative flow directors and spacer ribs. [Diagram 42] 42 with flow directors and spacer ribs in the alternative flow director form of FIG. 41. FIG. [Diagram 43] 31 is an enlarged cross-sectional view taken along line UU of the cushion module of FIG. 30 with another alternative flow director and another alternative spacer rib. [Diagram 44] 44 is an enlarged cross-sectional view taken along line AA-AA of FIG. 30 with the alternative flow director and spacer ribs of FIG. 43. [Diagram 45] 31 is an enlarged perspective cross-sectional view from above along line UU of the cushion module of FIG. 30 with another alternative flow director and spacer ribs. [Diagram 46] 46 is a perspective enlarged cross-sectional view taken along line AA-AA of FIG. 30 with the alternative flow director of FIG. 45; FIG. [Figure 47] 31 is an enlarged cross-sectional view taken along line UU of the cushion module of FIG. 30 with another alternative flow director, spacer ribs and reinforcement section. [Figure 48] 48 is an enlarged cross-sectional view taken along line BB-BB of FIG. 30 with the flow director, spacer rib and reinforcing section of FIG. 47; [Figure 49] 48 is an enlarged cross-sectional view taken along line YY of FIG. 30, with the flow director, spacer rib and reinforcing section of FIG. 47; [Figure 50] 31 is an enlarged cross-sectional view taken along line UU of the cushion module of FIG. 30 with another alternative flow director and another alternative spacer rib. [Figure 51] 51 is an enlarged cross-sectional view taken along line AA-AA of FIG. 30 with the alternative flow director and spacer ribs of FIG. 50; [Figure 52] 31 is an enlarged cross-sectional view of the cushion module of FIG. 30 taken along line UU with alternative proximal and distal portions of the partition wall. [Diagram 53]31 is an enlarged cross-sectional view of the cushion module of FIG. 30 taken along line UU with alternative proximal and distal portions of the partition wall. [Figure 54] 31 is an enlarged cross-sectional view of the cushion module of FIG. 30 taken along line UU with alternative proximal and distal portions of the partition wall. [Figure 55] 55 is an enlarged perspective view of a cross section of the cushion module of FIG. 31 along line CC-CC, with flow directors, spacer ribs, and with the proximal and distal portions of FIG. 54. FIG. [Figure 56] FIG. 32 is an enlarged cross-sectional view of the cushion module of FIG. 31 taken along line DD-DD, with a further alternative flow director; [Figure 57] 57 is an enlarged cross-sectional view of the cushion module of FIG. 33 along line EE-EE with the alternative flow director of FIG. 56. [Figure 58] FIG. 34 is an enlarged perspective cross-sectional view of the cushion module of FIG. 33 along line EE-EE with a further alternative flow director. [Figure 59] 58 is an enlarged cross-sectional view of the cushion module of FIG. 31 along line CC-CC with the flow director of FIG. 58. [Figure 60] 58 is an enlarged cross-sectional view of the cushion module of FIG. 30 along line UU, the cushion module having the flow guide of FIG. 58. [Figure 61] FIG. 34 is an enlarged perspective view of a cross-section of the cushion module of FIG. 33 taken along line EE-EE, with a further alternative flow director. [Figure 62] 62 is an enlarged perspective view of a cross section of the cushion module of FIG. 30 along line FF-FF with the alternative flow director of FIG. 61. FIG. [Figure 63] 62 is an enlarged cross-sectional view of the cushion module of FIG. 30 along line UU, with the flow guide of FIG. 61. [Figure 64] FIG. 31 is a top plan view of a section taken along line YY of FIG. 30 with a further alternative flow director. [Fig. 65A-B]65 is an enlarged cross-sectional view along line UU of the cushion module of FIG. 30 with the alternative flow director and spacer ribs of FIG. 64 and with an alternative proximal portion of the divider wall. [Figure 66] 65 is an enlarged cross-sectional view along line UU of the cushion module of FIG. 30 with the alternative flow director and spacer ribs of FIG. 64 and with an alternative configuration of the proximal and distal portions of the partition wall. [Figure 67] 65 is an enlarged cross-sectional view along line HH-HH of the seal member only of FIG. 30 with the flow director of FIG. 64 and with an alternative distal portion of the partition wall. [Figure 68] 68 is a bottom perspective view of an enlarged cross-section taken along line HH-HH of the seal member only of FIG. 30 with the flow director of FIG. 64 and with the alternative distal portion of FIG. 67; FIG. [Figure 69] 68 is an enlarged cross-sectional view along line UU of the seal member only of FIG. 30 with the flow director of FIG. 64 and with an alternative distal portion of the partition wall of FIG. 67. [Figure 70] 65 is a top plan view of a cross section taken along line YY of FIG. 30 with the alternative flow director of FIG. 64 and with a flow director tether. [Figure 71] 70 is a perspective view of an enlarged cross section taken along line UU of the cushion module of FIG. 30 having the flow director of FIG. 64 and the flow director tether of FIG. 70, viewed from above. [Figure 72] 65 is an enlarged cross-sectional view taken along line UU of the seal member of FIG. 30 only, with the flow director of FIG. 64 and with a tether extending from the deformed panel; [Figure 73] 73 is a perspective bottom view of a cross section taken along line BB-BB of the seal member only of FIG. 30 with the tether of FIG. 72. FIG. [Figure 74] 73 is an enlarged bottom plan view of a cross section taken along line BB-BB of the seal member only of FIG. 30 with the tether of FIG. 72. FIG. [Figure 75] 65 is an enlarged cross-sectional view along line UU of the seal member only of FIG. 30 with the flow director of FIG. 64 and with an alternative tether arrangement. [Figure 76] 76 is a perspective bottom view of a cross section taken along line BB-BB of the seal member only of FIG. 30 with the alternative tether arrangement of FIG. 75. FIG. [Figure 77] 76 is an enlarged bottom plan view of a cross section taken along line BB-BB of the seal member only of FIG. 30 with the alternative tether arrangement of FIG. 75. FIG. [Figure 78] FIG. 65 is a top plan view of a cross section of a cushion module along line YY of FIG. 30 with the alternative flow guide of FIG. 64 and with a reinforcing structure. [Figure 79] 78. An enlarged cross-sectional view of the cushion module of FIG. 30 along line UU, the cushion module having the flow guide of FIG. 64 and the reinforcing structure of FIG. [Figure 80] 65 is an enlarged cross-sectional view of the cushion module of FIG. 30 along line UU, the cushion module having the flow guide of FIG. 64 and a deformation region tether. [Figure 81] 81 is a bottom plan view of a cross-sectional view along line GG-GG of the cushion module of FIG. 30 with the deformation region tether of FIG. 80. FIG. [Figure 82] 81 is a perspective bottom view of a cross section taken along line GG-GG of the seal member only of FIG. 30 with the deformation region tether of FIG. 80. FIG. [Figure 83] 31 is an enlarged cross-sectional view of the cushioning module of FIG. 30 along line AA-AA with an alternative flow director and with an alternative deformation region tether. [Figure 84] 84 is an enlarged cross-sectional view of the cushioning module of FIG. 30 along line UU, with the flow director and deformation region tether of FIG. 83. [Figure 85] FIG. 31 is a top plan view of a cross section taken along line YY of the cushion module of FIG. 30 with an alternative arrangement of flow directors. [Figure 86] 86 is a bottom plan view of a cross-sectional view of the cushion module of FIG. 30 along line GG-GG with the flow director arrangement of FIG. 85. [Figure 87]FIG. 86 is a top perspective view of a cross-section of the cushion module of FIG. 30 taken along line YY with an alternative arrangement of the flow director of FIG. 85. [Figure 88] FIG. 31 is a top plan view of a cross section taken along line YY of the cushion module of FIG. 30 with a single flow director arrangement. [Figure 89] FIG. 89 is a bottom plan view of a cross-section taken along line GG-GG of the cushion module of FIG. 30 with a single flow director arrangement of FIG. 88. [Figure 90] FIG. 89 is a perspective view from above of a cross section taken along line YY of the cushion module of FIG. 30 with a single flow director arrangement of FIG. 88. [Figure 91] FIG. 34 is a top perspective view of a cross-section of the cushion module of FIG. 33 along line LL-LL, with channels from the oral chamber to the nostril openings. [Figure 92] FIG. 92 is an enlarged cross-sectional view of the cushion module of FIG. 33 along line KK-KK with the channel of FIG. 91 . [Figure 93] FIG. 92 is a bottom plan view of a cross section taken along line BB-BB of the cushion module of FIG. 30 with the channel of FIG. 91. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0490] Preferred embodiments of the present invention will now be described in the following text, including reference numerals that correspond to features illustrated in the accompanying drawings. Where possible, the same reference numerals are used to identify the same or substantially similar features in different embodiments. However, in order to maintain clarity of the drawings, not every reference numeral may be included in each figure.

[0491] Aspects of the patient interface disclosed above are described in detail below with reference to an embodiment of the patient interface in schematic form shown in Figures 1-4. The embodiments described below are variations of that schematic form. However, it will be understood that the scope of the aspects should not be limited by reference to that schematic form or the specific embodiments described below, but instead the aspects should be construed as relating to other forms of patient interfaces that similarly deliver pressurized breathing gas to a patient, including patient interfaces that extend across the bridge of the nose, full face masks and full head helmets.

[0492] The term "respiratory gas" as used throughout this specification shall mean the gas used in human breathing. The term "inhaled respiratory gas" as used throughout this specification shall mean the respiratory gas that is inhaled during the inhalation phase of the respiratory cycle. This term includes within its scope ambient air or air that has been conditioned to treat the patient, such as having elevated humidity or oxygen concentration or both compared to ambient air. The term "exhaled respiratory gas" as used throughout this specification shall mean the respiratory gas that is exhaled from the lungs and airways of a patient. It therefore includes the respiratory gas from the lungs that occupies the anatomical dead space at the end of the expiratory phase of the respiratory cycle.

[0493] 1-4, the schematic form comprises a patient interface 10 including a cushion module 20, a frame 30 and a conduit connector 40. The conduit connector 40 comprises a structural component that connects the cushion module to a source of respiratory gas, such as a ventilator, humidifier, flow generator or wall source. In this embodiment, the patient interface 10 is in the form of an under-the-nose mask in which the cushion module 20 comprises an elastic sealing member 230 and a housing 210. The elastic sealing member 230 and the housing 210 collectively form an outer wall 288 of the cushion module 20.

[0494] 6 without the seal member 230, the housing 210 is formed from a substantially rigid plastic material that provides structural support to the seal member 230. In addition, the housing 210 provides an interface for connecting the seal member 230 to the frame 30 and the conduit connector 40.

[0495] The housing 210 includes a sleeve 220 that is sized and shaped to connect with the frame 30. The sleeve 220 defines an inlet opening 292 that allows breathing gas to pass from the conduit connector 40 to the interior of the cushion module 20. The sleeve includes keying structure 222 that interacts with the frame 30 to ensure proper alignment of the frame 30 with the housing 210 when the frame 30 and housing 210 are mated.

[0496] The housing 210 includes a series of tabs 212 projecting outwardly around its periphery. The outer ends of the tabs 212 are connected to beads 214 that extend continuously around all of the tabs 212, thereby forming a series of discontinuous outer overmolded windows 216 between the tabs 212 and the beads 214. The seal member 230 is integrally formed with the housing by overmolding a resilient material onto the housing 210 to fill the series of windows. The tabs 212 and beads 214 are thus embedded in the resilient material and mechanically interlocked with the seal member 230. The seal member 230 and housing 210 thus form a one-piece cushion module 20 structure.

[0497] The housing 210 further includes a group of bias vents 226 that extend through the housing 210. The housing further includes a series of inner overmold windows 218 through which the seal member 230 is also overmolded with the housing 210. The inner overmold windows 218 are located in an area of ​​the housing 210 that is within the perimeter defined by the outer overmold window 216. The bias vents 226 are bounded on one side by the outer overmold window 216 and on another side by the inner overmold window 218. As shown in FIG. 6, the bias vents 226 are surrounded by the outer overmold window 216 and the inner overmold window 218. The material used to form the seal member 230 flows through the inner overmold window 216 and the outer overmold window 218 during molding so that the material conforms to the shape of the housing 210 and the windows 216, 218 before solidifying or curing. The material extends through the windows 216, 218 to provide a mechanical connection with the housing. The windows 216, 218 may take the form of openings that extend completely through the housing 210.

[0498] The seal member 230 is formed of a soft, resilient material, such as silicone, and includes an oral opening 232 and a nasal opening 234. When attached to a patient, the oral opening 232 surrounds the patient's mouth and the patient-contacting surface 290 of the outer wall forms a seal around the mouth. Thus, breathing gases at elevated pressure can be delivered to the patient via the oral opening 232. The seal member 230 is formed with a nostril sealing portion 236, in whose valley the nostril openings 234 are located. The patient-contacting surface 290 includes a nostril sealing portion 236 and a wall portion 276 located between the oral opening 232 and the nasal openings 234. The nostril sealing portion 236 is positioned to contact the underside of the patient's nose and form a seal with the patient's nares, thereby allowing breathing gases at elevated pressure to be delivered to the patient via the nasal openings 234. The nasal openings 234 are positioned to align with the patient's nares when the mask 10 is attached.

[0499] While this embodiment of the cushion module 20 includes a single oral opening 232 and a single nostril opening 234, it will be understood that other embodiments may include more than one oral opening, more than one nostril opening, or multiple oral openings and multiple nostril openings. In another embodiment not shown, the cushion module includes a single oral opening 232 along with two nostril openings 234.

[0500] The cushion module 20 defines an interior volume including a first chamber 238 and a second chamber 240. The second chamber 240 is located in an upper portion of the interior volume of the seal member 230. The first chamber 238 constitutes a lower portion of the interior volume of the cushion module 20. The first chamber 238 and the second chamber 240 are separated by a partition wall 242. The first cavity is the first chamber 238 and the second cavity is the second chamber 240. As shown in FIGS. 3 and 4, the oral opening 232 is associated with the first chamber 238 to allow transfer of respiratory gas between the first chamber 238 and the patient's mouth. The inlet opening 292 of the sleeve 220 is also associated with the first chamber 238. The nostril opening 234 is associated with the second chamber to allow transfer of respiratory gas between the second chamber 240 and the patient's nares. The bias vent 226 is also associated with the second chamber 240. Thus, the bias vent 226 allows breathing gas to be vented from the cushion module to the external environment. In this embodiment, the bias vent 226 vents breathing gas to the surrounding atmosphere.

[0501] The partition wall 242 divides the cushion module 20 internally to define a first chamber 238 and a second chamber 240. The partition wall 242 extends across the entire interior volume of the cushion module 20, thereby separating the first chamber 238 from the second chamber 240. In other words, the periphery of the partition wall 242 seals with the outer wall 288. In Figs. 3 and 7, an abutment line 282 is shown which conceptually shows where the partition wall 242 abuts with the outer wall 288. In particular, the abutment line 282 extends completely across between the first chamber 238 and the second chamber 240. Sealing the first chamber from the second chamber means that the only flow of breathing gas between the first and second chambers is through the flow director 246. As such, the partition wall 242 seals the first chamber 238 from the second chamber 240 while allowing breathing gas to flow from the first chamber 238 to the second chamber 240 only through a pair of flow guides 246 (see Figures 8 to 11).

[0502] The divider wall 242 of the cushion module 20 has a broad U-shaped transverse profile. This is illustrated in Figures 3 and 7 by the line of abutment 282 that extends below the biased vent 226, across the ridges on either side of the nostril sealing portion 236, and across the wall portion 276. The U-shaped profile allows some vertical movement of the divider wall 242 (and the flow director 246), which helps maintain the spacing between the flow director 246 and the nostril opening 234 (which also moves vertically when a deforming force is applied to the nostril sealing portion 236), reducing the risk of the flow director contacting the patient. The broad U-shaped profile of the divider wall 242 is replaced with a flatter profile in later embodiments described below.

[0503] 8 and 9 show that the partition wall 242 seals with the outer wall 288 between the nasal openings 234 and the oral opening 232. In terms of the wall portion 276, this means that the partition wall 242 seals with the wall portion 276 across the entire width of the wall portion 276. In other words, the partition wall 242 seals with the outer wall 288 at a location spaced apart from the nasal openings 234. It can also be seen in FIGS. 8 and 9 that the partition wall 242 seals with the outer wall 288 closer to the oral opening 232 than to the nasal openings 234. In other words, the seal between the partition wall 242 and the wall portion 276 is located in the lower half of the wall portion 276.

[0504] One design consideration for the seal member 230 involves balancing patient comfort and therapeutic performance. Therapeutic performance is improved by ensuring that the flow structures that direct respiratory gases into the nares, such as the flow directors 246 in this embodiment, retain their shape and remain correctly oriented when the patient interface is attached to the patient. Some patient interfaces couple the structures to the patient-contacting surface 290. Often the coupling is at the nose-contacting region of the patient-contacting surface 290, i.e., the nose-contacting surface. In this embodiment, the partition wall 242 has been moved to a lower position within the interior volume of the cushion module 20. Positioning the partition wall 242 lower moves the junction between the partition wall 242 and the outer wall 288 away from the nose-contacting surface. This is expected to improve patient comfort. However, the partition wall 242 can be formed such that there is additional support structure that helps to retain the shape and orientation of the flow directors 246, so that therapeutic performance can be sustained. This means that the structure is less reliant on the connection with the outer wall 288 for support, which is why the flow director 246 of the cushion module 20 only has a small contact area with the outer wall 288. The additional support structure built into the partition wall 246 improves the resilience of the partition wall 242 and improves the resilience of the connection with the outer wall, but the lower position of the partition wall 242 results in the connection between the partition wall 242 and the outer wall 288 being moved away from the highly sensitive nostril contact area. This movement of the connection of the partition wall 242 with the outer wall 288 improves patient comfort compared to connections and connections in the nose contact area. That is, by reducing the connections between structures such as the flow director 246 and the outer wall 288, there are fewer structural contact points with the outer wall 288 that can create pressure points on the patient's face, which improves patient comfort. The facial contact points affected by the patient interface 10 during use include highly sensitive areas such as the nasal septum and philtrum. By employing a lower position of the divider wall 242 between the nostril openings 234 and the oral opening 232, it is expected that patient comfort will be improved.It is also anticipated that this will be enhanced by reducing contact between the internal structures of the cushion module 20 and the patient-contacting surface 290. Additionally, the increased volume of the second chamber 240 allows structures within the second chamber 240, such as the flow director 246, to be further supported and reinforced by the partition wall 242. As noted above, it is anticipated that in other embodiments, the flow director will be spaced apart from the outer wall 288 such that the partition wall 242 will be the only connection between the flow director and the cushion module 20.

[0505] The flow director 246 extends from the partition wall 242 into the second chamber 240. In other embodiments, the flow director 246 may extend from the partition wall 242 into the first chamber 238 and the second chamber 240, or only into the first chamber 238. In another embodiment, the flow director 246 may not extend from either side of the partition wall 242. For example, the partition wall 242 can have a wall thickness sufficient to include the flow director 246 between the surfaces of the partition wall 242 exposed to the first chamber 238 and the second chamber 240, respectively.

[0506] The flow director 246 defines and encloses a gas flow path from the first chamber 238 to the second chamber 240. Each flow director 246 comprises a body 248 having a first opening 250 and a second opening 252. The first opening 250 opens into the first chamber and the second opening 252 opens into the second chamber 240. This means that the flow director 246 is the only path through which breathing gases can flow between the first chamber 238 and the second chamber 240.

[0507] The flow guides 246 are disposed in the main portion 244 of the partition wall 242. In this embodiment, the body 248 of each flow guide 246 joins the partition wall 242. A small segment of the body 248 joins the outer wall 288 at the wall portion 276. As a result, the first chamber 238 is separated from the second chamber 240 by the partition wall 242 joining the outer wall 288 and the flow guide 246, and by the flow guide 246 joining the outer wall 288. In other embodiments, the body 248 of each flow guide 246 may be spaced apart from the outer wall 288 such that the entire periphery of the partition wall 242 joins the outer wall 288. In other words, the body 248 of each flow guide 246 may be located in a central region of the partition wall 242 such that each flow guide 246 is spaced apart from the periphery of the partition wall 242. The central region may be coincident with the center of the divider wall or may be offset from the center of the divider wall, however, in each embodiment, the first chamber 238 is separated from the second chamber 240 by the divider wall 242 and the flow director 246.

[0508] In this embodiment, the entire seal member 230 is integrally molded and overmolded onto the housing 210. This integral molding with the outer wall 288 of the partition wall 242 creates an airtight joint. The same applies when the flow director 246 interfaces with the partition wall 242.

[0509] The second opening 252 is positioned to direct breathing gas toward and through the nostril opening 234. This directs breathing gas from the first chamber 238 through the second opening 252 and through the nostril opening 234 to the patient's nares. The directed breathing gas assists breathing during the breathing cycle and contributes to flushing of anatomical dead space within the patient's nasal passages. It should be understood that while at least a portion of the gas flow directed by the flow director 246 toward the nostril openings 234 generally flows through the nostril openings 234, some of the directed gas may not flow through the nostril openings 234. Furthermore, at some points during use of the patient interface, the directed breathing gas may not flow through the nostril openings 234 at all. The flow of gas through the nostril openings 234 depends on the gas flow rate, the gas pressure, and the point in time in the breathing cycle. The directed flow of breathing gas from the flow director 246 that does not flow through the nostril openings 234 flows through the second chamber 240 to the bias vent 226 .

[0510] The location and shape of the second openings 252 affect the flow of respiratory gas into the second chamber and through the nostril openings 234. In the embodiment shown in Figures 8-10, each flow director 246 has a second opening 252 in the second chamber 240, the second openings 252 being spaced apart from the nostril openings 234. The second openings 252 are defined by a rim 254 that is contoured such that at least a portion of the rim 254 is substantially consistently spaced apart from the nostril openings 234. The portion of the rim 254 that is substantially consistently spaced apart from the nostril openings 234 is adjacent to at least the outer wall 288 between the nostril openings 234 and the oral opening 232. The rim 254 of each second opening 252 extends further from the partition wall 242 laterally outboard of the flow director 246 than the rim 252 extends from the partition wall 242 laterally inboard of the flow director 246. This means that the rim 254 is further recessed from the nostril opening 234 on the laterally inner side of the flow director 246 than the rim 254 is recessed from the nostril opening 234 on the laterally outer side of the flow director 246. The lower height of the rim relative to the divider wall 242 on the laterally inner side of each flow director 246 promotes the flow of breathing gas from the first chamber 238 to the second chamber 240. The higher height of the rim relative to the divider wall 242 on the laterally outer side of each flow director 246 promotes the directing of breathing gas from the first chamber 238 through the second chamber 240 and through the nostril opening 234. In another embodiment, the rim 254 is recessed most from the nostril opening 234 at a point between the laterally outer side of the flow director 246 and the laterally inner side of the flow director 246 such that in cross section the rim 254 is concave, i.e., curves inwardly.

[0511] The recessed position of the second opening 252 relative to the nostril opening 234 allows excess breathing gas from the first chamber 238 (including exhaled breathing gas from the mouth) to enter the second chamber 240 and exit through the bias vent 226 to the exterior of the patient interface 10. The nostril opening 234 is defined by a rim 286 at the outer wall 288 of the seal member 230. However, considering that the second opening 252 is recessed from the rim 254, the spacing between the second opening 252 and the rim 286 allows breathing gas to flow from the first chamber 238 to the second chamber 240 and then out through the bias vent 226 to the surrounding atmosphere. This generally occurs during a portion of the expiratory phase of the breathing cycle. For example, when the patient exhales through the nose (excess breathing gas delivered from the source to the first chamber 238 flows into the second chamber 240). Another example occurs when a patient exhales through the mouth (the exhaled gases flow from the mouth into the first chamber and then into the second chamber along with excess respiratory gases delivered from the source). Sometimes during nasal inspiration or nasal dead space flushing, respiratory gases may flow from the first chamber 238 into the second chamber 240 and then through the nostril openings 234 into the patient's nostrils.

[0512] The body 248 of each flow director 246 includes a lower body portion 256 and an upper body portion 258. The overall profile of the body 248 has a cross-sectional area that decreases in a direction between the first opening 250 and the second opening 252. In this embodiment, the body 248 includes a lower body portion 256 and an upper body portion 258. The lower body portion 256 tapers significantly from the first opening 250 to the upper body portion 258, and the upper body portion 258 tapers slightly from the lower body portion 256 to the second opening 252. However, in other embodiments, the upper body portion 258 may have a cross-sectional area that is smaller than the cross-sectional profile of the lower body portion 256. This may be embodied with a stepped profile of the body 248. The reduction in cross-sectional area between the first opening 250 and the second opening 252 has the effect of accelerating the breathing gas toward the nostril openings 234 to deliver an accelerated stream of breathing gas to the nostrils. In further embodiments, the body 248 of each flow director may have a constant cross-sectional area between the first opening 250 and the second opening 252 .

[0513] In this embodiment, the lower body portion 256 and the upper body portion 258 have a conical profile. In alternative embodiments, the upper body portion 258 may have a circular, elliptical, or oval profile in a cross section generally parallel to the divider wall in which the flow director is located. Additionally, the body 248 may have a conical, tapered, or stepped profile in a cross section generally perpendicular to the divider wall 242 in which the flow director 246 is located.

[0514] In the embodiment shown in Figures 8-19, the patient interface 10 includes two flow directors 246 spaced apart. That is, the two flow directors 246 constitute two separate structures. They do not share a common wall that defines a flow path through each of the flow directors 246. The flow directors 246 are spaced apart by a gap through which breathing gas from the first chamber 238 and exhaled breathing gas from the nostrils that enter the second chamber via the nasal openings 234 can flow into the second chamber. The rim 254 of each flow director 246 does not extend from the partition wall 242 on the same side as the gap in the flow directors 246 as much as the rim 254 extends on the side away from the gap in the flow directors 246. In this embodiment, the flow directors 246 are configured such that the lateral outer side of the rim 254 is adjacent to the lateral outer rim 286 of the nasal openings 234 when considering the direction of gas flow from the flow directors 246. More specifically, the rim 254 is located laterally inward of the rim 286 laterally outward of the nostril opening 234. However, in other embodiments, the rim 254 may be located laterally outward of the rim 286 laterally outward of the nostril opening 234, or the laterally outward of the rim 254 may be aligned with the rim 286 laterally outward of the nostril opening 234, taking into account the direction of gas flow from the flow director 246.

[0515] Spaced apart positioning of the flow directors 246 laterally outboard of the nostril openings 234 is expected to improve patient comfort due to reduced contact points with the outer wall 288. As explained above, reduced contact points reduce the number or size of pressure points on the patient's face. Furthermore, the laterally spaced apart contact points move the contact points away from the sensitive nasal septum and philtrum areas. The expected increased comfort should contribute to improved compliance with treatment and reduce pressure sores. Furthermore, the lateral location of each of the two flow directors 246 with respect to the nostril openings 234 is believed to improve the likelihood that the flow directors 246 will align with the patient's nares and therefore deliver sufficient flow rates. This is because the laterally spaced apart positions of the flow directors 246 reduce the likelihood that a patient with a wide or large nasal septum (centrally located with respect to the nostril openings 234) will obstruct the flow out of the flow directors 246.

[0516] A bead 262 surrounds a rim 286 on the inner surface of the seal member 230. The bead 262 includes an area of ​​increased wall thickness, in this embodiment, as shown in Figure 4. The increased thickness of the rim 286 increases the resistance of the rim 286 to prevent excessive outward deformation, otherwise known as a blowout, which may occur when the patient interface 10 receives high levels of pressurized breathing gas from a gas source. The increased thickness of the rim 286 also increases the resistance of the rim 286 to undesirable deformation that may occur when the patient interface 10 is attached to a patient.

[0517] The divider wall 242 is configured to preferentially deform to reduce the likelihood that the second chamber 240 and the nostril openings 234 become blocked.

[0518] In this embodiment, the partition wall 242 includes a main portion 244 and a first elastic region 268 connected by a deformation panel 294. In this embodiment, the first elastic region 268 has the shape of a lip. The deformation panel 294 includes a first wall 270 and a second wall 272. The first wall 270 protrudes from the first elastic region 268 (see FIG. 9 ), and the second wall 272 extends from the main portion 244 between the flow director 246 and the second wall 272 and joins with the first wall 270. The second wall 272 has a curved profile that extends from the first wall 270 to the main portion 244. FIG. 9 shows the first wall 270 and the second wall 272 in their undeformed configuration.

[0519] The deformation panel 294 structurally decouples the first elastic region 268 from the main portion 244. This decoupling occurs because the deformation panel 294 accommodates the reduced distance between the first elastic region 268 and the main portion 244.

[0520] The deformation of the deformation panel 294 occurs in two stages. The main portion 244 includes the flow director 246 and is therefore relatively less deformable in the area of ​​the flow director 246 compared to the first wall 270 and the second wall 272. Thus, the deformation panel 294 deforms more easily than the remainder of the main portion 244. The first stage of deformation involves the application of a force to the patient contacting surface 290 such that the main portion 244 is displaced towards the first resilient region 268. This causes the first wall 270 to fold over about the connection line with the first resilient region 268 until it contacts or is adjacent to the underside of the first resilient region 268. In the second stage of deformation, as the main portion 244 continues to displace towards the first resilient region 268, the second wall 272 and that section of the main portion 244 buckle and the flow director 246 translates over the first wall 270 until it contacts or is adjacent to the first resilient region 268. This buckling and translational motion can be referred to as "rolling." The buckling occurs due to the curvature of the second wall 272. This series of deflections is shown and described in International Patent Application No. PCT / NZ202 / 050072, with particular reference to Figures 59A-59D and the associated description, the contents of which are incorporated herein by this reference and therefore these applications are to be read as a single disclosure.

[0521] In alternative embodiments, the partition wall 242 may be configured such that deformation of the deformation panel 294 is limited to the first stage of deformation described above. For example, the second wall 272 may be omitted, or may be reduced in size or have a modified shape that avoids "rolling" motion. In a further alternative, the first wall 270 may extend further from the first elastic region 268 such that the first stage of deformation occurs for all displacements of the main portion 244 towards the first elastic region 268.

[0522] During use, when the mask 10 is fitted, forces are applied to the patient contacting surface 290 to account for different face shapes, headgear preferences and pressure settings. These forces, and the locations at which they are applied, vary. However, the configuration described above concentrates the forces and deflections at the deformation panel 294 to provide a predictable collapse and rebound motion. Due to the predictable buckling pattern achieved through the preferred deformable regions, the mask 10 can be designed such that when a force is applied to the seal, the resulting deformation and compression that occurs in the elastomeric material forming the seal member 230 occurs in such a way that the nostril openings 234 and the second openings 252 from the flow director 246 are likely to remain unobstructed. Furthermore, the positioning of the nostril openings 234 and the second openings 252 relative to one another is substantially maintained during deformation. Without this preferential deformation, collapse of the divider wall 242 would be unpredictable, potentially resulting in inconsistent flow through the second opening 252 or inconsistent positioning of the second opening 252 relative to the nostril opening 234 and / or patent nostril. This would result in inconsistencies in therapy achieved, comfort, installation procedure, and overall performance both between uses on the same patient and between different patients.

[0523] In variations on this embodiment, the seal member 230 may have more than one region of preferential deformation. For example, additional regions of preferential deformation may be incorporated into the divider wall 242 or in other locations on the seal member 230 that enable the second chamber 240 and / or the nostril openings 234 and second openings 252 to substantially retain their shape.

[0524] The shapes of the first and second walls 270, 272 and their thicknesses are selected to enable the cushion module 20 to accommodate a wide range of facial shapes and deformation forces associated with application and use of the patient interface. However, it is also possible to manufacture different cushion modules to accommodate a range of facial shapes towards either end of the facial shape spectrum.

[0525] The first elastic region 268 is formed with a greater wall thickness to provide greater elasticity compared to the deformation panel 294, thereby allowing a single material to be used to form the seal member 230. However, it will be appreciated that the first elastic region 268 may be stiffened by alternative means, provided that the deformation panel 294 preferentially deforms when a force is applied to the seal member 230. For example, the first elastic region 268 may be formed of a more elastic material (such as a different grade of silicone or plastic material) or may have a different construction.

[0526] The transfer of deformation forces to the deformation panel 294 is aided by one or more reinforcement sections 264 formed in the partition wall 242. In this embodiment, the reinforcement section 264 comprises a thickened wall section located on the underside of the partition wall 242, as shown in FIG. 11 and in cross section in FIGS. 8 and 9. The reinforcement section 264 takes the form of a rib having a force spreading end 266 that connects to a wall portion 276 of the outer wall 288. The force spreading end 266 tapers outward in the direction of the wall portion 276. This spreading distributes the contact area of ​​the reinforcement section 264 over a larger area of ​​the wall portion 276. This provides a larger contact point over which the forces are spread. Reducing the flexibility of the wall portion 276 affects patient comfort by providing hard local contact points on the patient contact surface 290. However, spreading the contact points improves patient comfort by reducing the contact pressure. The reinforcement section 264 redirects forces applied to the wall portion 276 towards the divider wall 242 where the deflection force is absorbed by the deflection panel 294. In doing so, the reinforcement section 264 substantially maintains the position of the divider wall 242 (and flow director 246) relative to the nasal openings 234. Another way to understand the effect of the reinforcement section 264 is to understand that the reinforcement section 264 secures the main portion 244 in place relative to the wall portion 276. This allows patient treatment to continue with little or no obstruction to the flow of respiratory gas (a) through the flow director 246, (b) through the nasal openings 234, and (c) through the second chamber 240 during deformation of the patient-contacting portion of the outer wall 288.

[0527] The function of the reinforcement section 264 is assisted by the spacer ribs 260 (FIG. 10). In this embodiment, the spacer ribs 260 have the form of ribs that connect both flow guides 246 and connect to the main portion 244 at a location where they overlap the reinforcement section 264 (see FIG. 9). The spacer ribs 260 extend part way up each flow guide 246. In this embodiment, the spacer extends from the partition wall to above the lower body portion 256. By connecting the spacer ribs 260 to the flow guides 246, the flow guides 246 are reinforced and made more resilient to deformation. By connecting the spacer ribs 260 to each flow guide 246, it is also ensured that any force applied to one flow guide 246 is transferred and propagated to the other flow guide 246, thereby reducing local deformation. By connecting the spacer ribs 260 to the flow guides 246, the possibility of the flow guides 246 buckling inwardly or outwardly is also reduced. The reduced likelihood of buckling helps to maintain alignment of the flow director 246 in a direction that directs the flow of breathing gas towards the nostril openings 234 when in use.

[0528] Additionally, the location of the spacer ribs 260 and the reinforcement sections 264 means that deflection of the wall portion 276 is transferred through the reinforcement sections 264 and the spacer ribs 260, thus causing the flow director 246 to follow the movement of the wall portion 276 and the nostril openings 234. The spacer ribs 260 also serve to maintain the position of the second openings 252 relative to one another, reducing the possibility of the second openings 252 collapsing inwardly or outwardly during deformation. In this embodiment, the spacer ribs 260 are integrally formed with the body 248 of the flow director 246. However, in other embodiments, the spacer ribs 260 may be located between the flow directors 246 but not joined to them. Alternatively, the spacer ribs 260 may join the flow directors 246 but not connected to the main portion 244. Although this arrangement does not overlap the reinforcement sections 264, the spacer ribs 260 still act to maintain the relative spacing of the second openings 252. In another alternative, the spacer ribs 260 or the reinforcement sections 264 may be omitted. The structure of the flow directors and either the spacer ribs 260 or the reinforcement sections 264 act to make the main portion more resilient to deformation, such that deformation forces are expected to be transferred to the preferential deformation regions in the absence of one or the other of the spacer ribs 260 or the reinforcement sections 264. Thus, the flow directors 246 are expected to retain their shape and position relative to the nostril openings 234 when subjected to deformation forces.

[0529] The manner in which the cushion module 20 delivers breathing gas to the patient, removes excess breathing gas, and removes exhaled breathing gas is similar to that described in International Patent Application PCT / NZ202 / 050072, in particular with reference to Figures 45-47 and the associated description. In summary with respect to the cushion module 20, the delivery of breathing gas to the patient is as follows: An accelerated stream of breathing gas is delivered to the patient to provide flushing of the anatomical dead space. This involves delivering breathing gas at an elevated pressure to a first chamber 238 of the cushion module 20. The first chamber 238 delivers breathing gas to the patient's mouth via the oral opening 232 and to a second chamber 240 via a flow director 246. The second chamber 240 delivers breathing gas to the patient's nares via the nasal openings 234. The flow of breathing gas towards the nares is accelerated through the flow director 246. The flow director 246 has a reduced cross-sectional area towards the nasal openings 234. The accelerated flow of breathing gas can then be delivered to the patient's nares. The accelerated flow of breathing gas occurs at the same time that breathing gas is allowed to be delivered from the first chamber 238 to the mouth.

[0530] In a further embodiment, the flow guide 246 does not reduce its cross-sectional area towards the second opening 252, but the flow guide 246 still accelerates gas from the first opening 250 towards the second opening 252 due to the restriction of gas entering the flow guide 246 from the first chamber 238.

[0531] Generally speaking, the patient interface 10 operates such that when the patient interface 10 is attached to a patient and the patient's mouth is open, the following occurs: a first flow path from the first chamber 238 through the oral opening 232 into the patient's mouth, then from the patient's oral cavity into the nasal cavity, exiting one or both of the nares via one or more nostril openings 234 into the second chamber 240, and exiting the patient interface via the bias vent 226; and A second flow path from the first chamber 238 through the flow director 246 into the second chamber 240 and out the patient interface through the bias vent 226. When the patient interface 10 is attached to a patient and a flow of pressurized gas is supplied to the patient interface 10, a first pressure P1 is generated in the first chamber 238 and a second pressure P2 is generated in the second chamber 240. The combination of the flow restriction located in the second flow path and the bias vent 226 located in the second chamber 240 creates a pressure differential between the pressure P1 in the first chamber 238 and the pressure P2 in the second chamber 240, where the pressure P2 in the second chamber 240 is lower than the pressure P1 in the first chamber 238. This pressure differential means that the pressurized gas supplied to the first chamber 238 will flow through both the first and second flow paths and exit the patient interface via the bias vent 226 in the second chamber 240.

[0532] The balance between the resistance to flow through the first flow path and the resistance to flow through the second flow path determines the proportion of pressurized gas delivered to the patient interface 10 through each flow path.

[0533] The second flow path is configured to have a sufficiently high flow resistance due to a flow restriction in the second flow path that at least a desired minimum portion of the pressurized gas flow provided to the patient interface 10 flows along the first flow path and out of the patient interface 10. This provides for flushing of the patient's anatomical dead space in at least the pharynx and nasal cavities. In some embodiments, the flow restriction in the second flow path (and thus the desired resistance to flow) is due to a restricted cross-section of the flow director 246. In other embodiments, a restriction can be provided at another location along the second flow path to provide the desired resistance to flow in the second flow path.

[0534] The patient interface 10 also generally operates such that when the patient's mouth is closed, there is only a single flow path from the first chamber 238, through the flow director 246, through one or more nostril openings 234 into one or both of the patient's nares and into the nasal cavity, after which the gas flow slows down, the flow direction reverses, and the gas flows through one or both of the patient's nares, through one or more nostril openings 234 into the second chamber 240, and out of the patient interface 10 through the bias vent 226. Due to the restricted cross-section of the flow director 246 and the large volume of gas flowing through the flow director 246 for the single flow path through the patient interface 10, the flow is accelerated therethrough, resulting in a spray effect that is directed towards and enters the patient's nares through one or more nostril openings 234. This spray effect into one or both nostrils results in flushing of the patient's anatomical dead space.

[0535] It should be understood that the above description describes some of the flow paths that are formed during use of the patient interface 10. The above would be observed if the patient interface 10 were attached to an anatomical model where no breathing is occurring. However, other flow paths may be formed, particularly during breathing through either the mouth or the nostrils. The following description provides some further details about certain situations during the respiratory cycle.

[0536] During mouth breathing, the majority of the supply of breathing gas to the first chamber 238 is inhaled by the patient through the oral opening 232. A portion of the breathing gas supplied to the first chamber 238 in excess of the tidal flow requirement flows from the first chamber 238 through the flow director 246. A portion of the gas flow through the flow director 246 may then flow through the nostril openings 234 into the nares to flush the patient's anatomic nasal dead space, while the remaining flow enters the second chamber 240 and exits the cushion module 20 via the bias vent 226. Additionally, or instead of the above-mentioned flow through the flow director 246, a portion of the breathing gas supplied to the first chamber 238 in excess of the tidal flow requirement may flow through the oral opening 232 into the patient's mouth, through the oral cavity and nasal cavities, through the patient's nares through one or more nasal openings 234 into the second chamber 240, and then out of the patient interface 10 through the bias vent 226, causing some flushing of the anatomical dead space. This is due to the pressure differential that is created between the first and second chambers, as discussed above. During exhalation, exhaled breathing gas flows from the mouth into the first chamber 238, where it mixes with the fresh breathing gas supplied to the first chamber 238. This mixture of exhaled and fresh respiratory gas then flows through the flow director 246, with a portion of the gas flow through the flow director 246 flowing into the nares through the one or more nostril openings 234 and flushing the patient's anatomical nasal dead space, while the majority of the exhaled and excess respiratory gas flows through the flow director 246 into the second chamber 240. The flow of respiratory gas into the second chamber 240 is facilitated by the recessed position of the second opening 252 relative to the rim 286 of the one or more nostril openings 234. The exhaled and excess respiratory gas then flows out of the second chamber 240 of the patient interface 10 via the bias vent 226.In most cases, the majority of the flushing of the mouth and upper throat occurs towards the end of the exhalation and / or inhalation cycle when the pressure in the patient's mouth and throat drops below the pressure of the breathing gas supplied to the first chamber, at which point flow enters the patient's oral cavity via oral opening 232, passes through the patient's nasal cavities, exits the nares, and enters the second chamber 240 via one or more nasal openings 234, thereby flushing the patient's nasal cavities, mouth, and upper throat with fresh breathing gas.

[0537] During breathing through the nose with the mouth closed, the breathing gas supplied to the first chamber 238 flows through the flow director 246 and is directed towards the nostrils. The breathing gas is inhaled through the nostrils. The breathing gas in excess of the tidal flow requirement flows from the flow director 246 into the second chamber 240 and then out of the patient interface 10 through the bias vent 226. During most of the exhalation phase, the pressure in the patient's naris is higher than the pressure of the breathing gas supplied, so the breathing gas cannot enter the naris, and therefore the breathing gas flows into the second chamber 240 and then out of the patient interface 10 through the bias vent 226. The exhaled breathing gas flows into the second chamber 240 through the gap between the flow director 246 and the nostril opening 234 and joins the flow of breathing gas out of the bias vent 226. However, towards the end of the expiratory phase, when the pressure within the nasal cavity drops below the pressure of the supplied breathing gas, the accelerated stream of breathing gas from the flow director 246 penetrates the nares, thereby flushing the anatomical dead space in the nasal cavity and upper throat with fresh breathing gas.

[0538] During open-mouthed nose breathing, breathing gas delivered to the first chamber 238 flows through the flow director 246 and is directed towards the nostrils. The breathing gas is inhaled through the nostrils via the nostril openings 234. A portion of the breathing gas in excess of the tidal flow requirement flows from the flow director 246 into the second chamber 240 and then out of the patient interface 10 via the bias vent 226. During open-mouthed nose exhalation, exhaled breathing gas enters the second chamber 240 via the nostril openings 234 and out of the patient interface 10 via the bias vent 226. At the same time, fresh breathing gas delivered to the first chamber enters the patient's mouth, passes through the patient's nasal passages, exits the nasal passages and enters the second chamber 240 via the nostril openings 234. This flushes the patient's anatomical dead space within the patient's mouth, upper throat and nasal passages with fresh breathing gas. Furthermore, towards the end of the expiratory phase, when the pressure within the nasal cavity drops below the pressure of the breathing gas exiting the flow guide 246, a portion of the supplied breathing gas can flow through the flow guide 246 and enter the nasal cavity, thereby flushing the anatomical dead space in the nasal cavity and upper throat with fresh breathing gas.

[0539] The dead space flushing described above replaces breathing gas with low oxygen content in the patient's anatomical dead space with breathing gas with higher oxygen content that is taken into the lungs at the beginning of the next inspiration cycle. The breathing gas with low oxygen content is pushed from the dead space into the second chamber 240 where it exits the patient interface 10 via the bias flow holes 226. The flushing of breathing gas with low oxygen content (or stated differently, high CO2 content) into the patient interface 10 means that breathing gas with low oxygen content is not available for inspiration at the beginning of the next breathing cycle. This is made possible in part because pressurized breathing gas is provided to the first chamber 238 and the bias vent 226 is located in the second chamber 240 so that there is a constant unidirectional flow through the patient interface 10, which removes breathing gas with low oxygen content from the patient interface 10 by pushing it out of the second chamber 240 via the bias hole 226.

[0540] Stated another way, the dead space flushing described above replaces breathing gas with a high carbon dioxide content in the patient's anatomical dead space with breathing gas with a lower carbon dioxide content that is taken into the lungs at the beginning of the next inspiration cycle. The breathing gas with a high carbon dioxide content is pushed out of the anatomical dead space into the second chamber 240 where it exits the patient interface 10 via the bias flow holes 226. The flushing of breathing gas with a high carbon dioxide content into the patient interface 10 means that breathing gas with a high carbon dioxide content is not available for inspiration at the beginning of the next breathing cycle.

[0541] Providing supplemental oxygen to the patient increases the oxygen concentration, but does not necessarily reduce the CO2 levels present in the anatomical dead space as much as flushing the anatomical dead space with ambient air would. As a result, an advantage of this approach is that improved outcomes can be achieved without the need for supplemental oxygen in the breathing gas delivered to the patient interface 10. This is particularly advantageous when supplemental oxygen is in short supply. This is further advantageous in that potential risks associated with providing supplemental oxygen to the patient can be avoided by eliminating or reducing the need for supplemental oxygen. Furthermore, removing breathing gas with a high carbon dioxide content from the patient's dead space can improve gas exchange within the lungs, and as a result, this approach can provide improved outcomes that cannot be achieved with supplemental oxygen alone.

[0542] Alternative embodiments of the cushion module 20 are described below that function in a similar manner as described above for the cushion module 20 in terms of delivering respiratory gas to the patient, removing excess respiratory gas, and removing exhaled respiratory gas.

[0543] The above-described embodiment includes supplying breathing gas from a gas source to the first chamber 238 and exhausting breathing gas from at least the second chamber. In this configuration of supplying and exhausting breathing gas, breathing gas flows from the first chamber 238 to the second chamber 240. However, in an alternative embodiment, the housing 210 may be reconfigured to receive a supply of breathing gas from a gas source to the second chamber 240 and exhaust breathing gas from the first chamber 238. In this configuration, breathing gas flows from the second chamber 240 to the first chamber 238 via the flow director 246. Although the cushion module embodiments described below relate to gas flow from the first chamber 238 to the second chamber 240, the same applies to the various cushion module embodiments described below, including variations of those embodiments. That is, those cushion module embodiments can be utilized with gas flow directions from the first chamber 238 to the second chamber 240 or from the second chamber 240 to the first chamber 238.

[0544] Although the above description of the seal member 230 is in the context of the features being integrally formed by a molding process, any one or more of the features may be formed separately and then assembled with the seal member 230. For example, the main portion 244 may be formed with an opening adapted to receive a preformed flow director unit including two spaced apart partial flow directors. One reason for employing this assembly method may be to form some features from different materials. With regard to the example flow director unit, the unit may be formed from a hard plastic material that has a significantly higher resistance to deformation than the same structure when formed from silicone. In a further example, the spacer ribs 260 and / or the reinforcing section 264 may be formed separately from the seal member 230 and joined at a later stage.

[0545] 12-15, a further variation of cushion module 20 is shown as cushion module 1020. Features of cushion module 1020 that are the same as features of cushion module 20 are indicated with the same reference numbers. Features that are not the same as features of cushion module 20 are indicated with similar reference numbers having a prefix that includes the numeral "1."

[0546] The cushion module 1020 can be used with the same housing 210, frame 30 and conduit connector 40 as disclosed for each of the cushion modules 10. However, the cushion module 1020 differs from the cushion module 20 in that the flow director 1246 has a body with a larger cross-sectional area to reduce resistance to the flow of breathing gas therethrough. Additionally, the body 1248 is formed to have a funnel-shaped lower body portion 1256 (see FIGS. 13 and 14). The lower body portion 1256 constitutes more than 50% of the extent to which the flow director 1246 protrudes from the partition wall 242.

[0547] The spacer ribs 1260 between the flow directors 1246 are formed such that there is a concave bridge connecting the flow directors 1246. This shape reduces the risk of contacting the patient's nose, particularly the patient's nasal septum, a known highly sensitive area. The concave shape allows the spacer to extend further up the sides of each flow director 1246, thus contributing a greater stabilizing effect to the flow directors 1246. The spacer ribs 260 of the cushion module 20 are offset from the center of the distance that the flow directors 246 span between the wall portion 276 and the second wall 272. In contrast, the spacer ribs 1260 are located at or near the center of their full range of dimensions. The more central location of the spacer ribs 1260 helps maintain the spacing of the second openings 1252. More specifically, the more central location reduces the tendency of the flow directors 1246 to collapse toward each other when a deformation force is applied to the wall portion 276.

[0548] A further difference is that the reinforcement section 1264 is spaced apart from the wall portion 276 (FIGS. 14 and 15). By eliminating the contact points between the reinforcement section 264 and the wall portion 276 (as in the cushion module 20), the local wall thickness of the wall portion 1276 is reduced, thus improving patient comfort. The lower body portion 256 of each flow director 246 sufficiently reinforces the main portion 244 such that deformation forces are directed from the wall portion 276 through the main portion 244 and into the deformation panel 294. The reinforcement of the main portion 244 eliminates the need for the reinforcement section 264 to connect with the wall portion 276 or for the reinforcement section 264 to have a force spreading end 266.

[0549] 16-23, a further variation of cushion module 20 is shown as cushion module 2020. Features of cushion module 2020 that are the same as features of cushion module 20 are indicated with the same reference numbers. Features that are not the same as features of cushion module 20 are indicated with similar reference numbers having a prefix that includes the number "2."

[0550] The cushion module 2020 differs from the cushion module 20 in that the flow director 2246 is connected to the outer wall 288 in the second chamber 240, as seen in Figures 19, 20 and 22. This means that the breathing gas flows through a channel formed partly by the body 2248 and partly by the outer wall 288. The connection where the body 2248 abuts the outer wall 288 is shown conceptually in Figures 16 and 17 by the abutment line 2280. Also shown in Figures 16 and 17 is the abutment line 282 between the partition wall 242 and the outer wall 288, where it can be seen that the abutment line 2280 intersects with the abutment line 282.

[0551] The flow director 2246 has a second opening 2252 defined in part by the rim 286 of the nostril opening 234 and in part by a rim 2254. The rim 2254 extends from the outer wall 288 and is recessed from the nostril opening 234 as shown in Figures 17, 18 and 20. The rim 2254 may extend from the rim 286 or may be recessed from the rim 286 such that there is no direct contact between the rim 2254 and the rim 286. Thus, the second opening 2252 defined by the rims 2254 and 286 is recessed from the nostril opening 234. This provides the same respiratory gas flow effect as described above with respect to the cushion module 20, i.e., respiratory gas from the first chamber 238 can flow through the flow director 2246 into the nostril or into the second chamber 240.

[0552] In this embodiment, the flow director 2246 is spaced farther apart than the flow directors 246 and 1246 of the cushion modules 20 and 1020, respectively. The additional spacing aligns the second opening 2252 with the laterally outer side of the patient's nares and provides greater spacing between the contact points where the body 2248 abuts the outer wall 288. The greater spacing is expected to improve patient comfort by moving the contact points away from the patient's nasal septum. Additionally, because the flow director 2246 is coupled to the outer wall, no equivalent of the spacer ribs 260 or 1260 (as in the above-described embodiment) is required since the flow director is less likely to collapse laterally inward.

[0553] The body 2248 of each flow director 2246 is coupled to the outer wall 288 between the nasal opening 234 and the oral opening 232. More specifically, the body 2248 of each flow director 2246 is coupled to the outer wall 288 at or adjacent to the nasal opening 234.

[0554] The flow directors 2246 are spaced apart such that a portion of the body 2248 joins with the outer wall 288 laterally outboard of the lateral rim 286 of the nostril opening 234 and another portion of the body 2246 joins with the laterally inboard of the lateral rim 286 of the nostril opening 234. In this configuration, each body 2248 has an outer wall 274a and an inner wall 274b, both of which extend from the wall section 276 and abut each other away from the wall section 276. Further, the outer wall 274a and the inner wall 274b extend from the divider wall 242 and abut the outer wall 288. The outer wall 274a joins with the outer wall 288 laterally outboard of the lateral rim 286 of the nostril opening 234 such that the rim 286 of the nostril opening 234 forms part of the rim 2254 of the flow director 2246. The inner wall 274b joins with the outer wall 288 laterally inward of the lateral rims 286 of the nostril openings 234 such that a portion of the inner wall 274b forms part of the rim 2254 of the flow director.

[0555] The rim 2254 of the second opening 2252 formed by the inner wall 274b is closer to the divider wall 242 than the rim 286 of the second opening 2252 formed by the lateral rims 286 of the nostril openings 234. As a result, the second opening of the flow director 2246 is defined, in part, by the nostril openings 234. This configuration of the second openings 2252 may have the effect of directing breathing gases laterally inward as they flow from the flow director 2246 into the second chamber 240.

[0556] In an alternative embodiment, the flow director 2246 may be coupled to the outer wall 288 at the first chamber 238 and the second chamber 240. In a further alternative embodiment, the body 2248 may be coupled to the outer wall 288 on the side of the nostril opening 234 opposite the wall portion 276.

[0557] The cushion module 2020 includes a reinforcement section 264 having a force spreading end 266. Thus, the primary and secondary deformation effects discussed above with respect to the cushion module 20 apply to the cushion module 2020 as well.

[0558] The cushion module 2020 includes an additional reinforcement section 2264 where the body 2248 of the flow director 2246 abuts the partition wall 242 (see FIGS. 17, 18, and 19). The reinforcement section 2264 is a thickened fillet where the respective body 2248 abuts the partition wall 242. The reinforcement section 2264 thus extends from the outer wall 288 on one side of the body 2248 and back to the outer wall 288 on the other side of the body 2248. The location of the reinforcement section 2264 serves to direct a deformation force applied to the wall portion 276 through the main portion 244 and into the deformation panel 294. The flow director 2246 is therefore more likely to retain its shape when a deformation force is applied because the deformation force is directed through the reinforcement section 2264 and around the base of the flow director 2246. In this configuration, the reinforcement section 2264 does not overlap the reinforcement section 2264.

[0559] 24-29, a further variation of cushion module 20 is shown as cushion module 3020. Features of cushion module 3020 that are the same as features of cushion module 20 are indicated with the same reference numbers. Features that are not the same as features of cushion module 20 are indicated with similar reference numbers having a prefix that includes the number "3."

[0560] The cushion module 3020 is similar to the cushion module 2020 in that the flow director 3246 is connected to the outer wall 288 as seen in Figures 25 and 29. This means that breathing gas flows through a channel formed partly by the body 3248 and partly by the outer wall 288. The connection where the body 3248 abuts the outer wall 288 is shown conceptually in Figure 24 by the abutment line 3280. Figure 26 also shows the abutment line 282 between the partition wall 242 and the outer wall 288, where it can be seen that the abutment line 3280 intersects with the abutment line 282.

[0561] The cushion module 3020 includes a flow director 3246 having a second opening 3252 defined in part by the rim 286 of the nostril opening 234 and in part by a rim 3254. The rim 3254 extends from the outer wall 288 and is recessed from the nostril opening 234, as shown in FIGS. 26 and 27. The rim 3254 is recessed from the rim 286. In this embodiment, the rim 3254 is joined to the bead 262. However, in other embodiments, the rim may be further recessed by joining the outer wall 288 adjacent to the bead 262. As shown in FIG. 27, the rim 3254 extends away from the outer wall 288. Thus, the second opening 2252 defined by the rims 2254 and 286 is recessed from the nostril opening 234. This provides the same breathing gas flow effect as described above with respect to the cushion module 20, ie, breathing gas from the first chamber 238 flowing into the nares or into the second chamber 240.

[0562] The cushion module 3020 further differs from the cushion module 2020 in that the reinforcement section 264 (shown in FIGS. 28 and 29) has a bifurcated force spreading end 3266. The force spreading end 3266 is spaced apart from the wall section 276. This is expected to reduce the pressure experienced by the patient through the wall section 276. The bifurcated force spreading end 3266 is shaped to extend slightly wider than the philtrum and / or nasal septum in most patients. (It will be appreciated that a vast range of facial shapes can be accommodated by a set of patient interfaces that are different sizes). For a given patient interface size, the force spreading end 3266 is shaped to extend slightly wider than the philtrum in most patients for whom that patient interface 10 size is suitable. The bifurcations are expected to reduce pressure on the patient's philtrum that is applied through the wall section 276 when the patient interface 10 is attached and therapy is applied. It will further be appreciated that by having two contact points due to the bifurcation, the force applied through each contact point can be halved. This means that the wall thickness of the wall section 276 can be reduced due to the reduced point load through the reinforcement section 264. In this embodiment, the wall section 276 has a wall thickness of 0.7 mm. Other embodiments may have different wall thicknesses for the body 3248 and the wall section 276.

[0563] An additional reinforcement section 3264 is included where the body 3248 abuts the partition wall 242 (see FIGS. 26 and 27). The reinforcement section 3264 does not extend to the exterior wall 288 in this embodiment, but may extend to the exterior wall in other embodiments. The location of the reinforcement section 3264 serves to direct deformation forces applied to the wall portion 276 through the main portion 244 and into the deformation panel 294. The deformation forces are thus directed through the bifurcated force spreading end 3266 that overlaps the reinforcement section 3264. This means that the flow director 3246 is more likely to retain its shape when subjected to a deformation force, since the deformation forces are transferred through the reinforcement section 3264 and around the base of the flow director 3246.

[0564] 30-40, a further variation of cushion module 20 is shown as cushion module 4020. Features of cushion module 4020 that are the same as features of cushion module 20 are indicated with the same reference numbers. Features that are not the same as features of cushion module 20 are indicated with similar reference numbers having a prefix that includes the number "4".

[0565] In this embodiment, the cushion module 4020 includes a partition wall 4242, a flow director 4246, and deformation regions similar to those described above with respect to the cushion module 20, all of which are described in more detail below.

[0566] The partition wall 4242 divides the cushion module 4020 internally to define the first chamber 238 and the second chamber 240. The partition wall 4242 extends across the entire interior volume of the cushion module, thereby separating the first chamber 238 from the second chamber 240. In other words, the periphery of the partition wall 4242 seals with the outer wall 288.

[0567] In comparison to the partition wall 242 of the cushion module 20, the partition wall 4242 has a flatter, though still curved, profile where it interfaces with the laterally positioned reinforcement portion 804 of the outer wall 288. The flatter profile reduces movement of the flow directors 4246 toward one another. As a result, the partition wall 4242 is configured to reduce collapse or buckling of the flow directors 4246. In either case, the partition wall 4242 is configured to reduce inward collapse or buckling of the flow directors 4246 toward one another.

[0568] More specifically, the partition wall 4242 in this embodiment has a flatter transverse profile than the partition wall 242. As shown in Figures 30, 31 and 33, the location where the partition wall 4242 joins with the outer wall 288 is indicated by an abutment line 4282. The abutment line 4282 extends across the wall portion 276 below the bias vent 226 and extends across the side of the cushion module 4020 along an imaginary line that is a continuation of a line that extends across the top of the housing 210.

[0569] In FIG. 34, it can be seen that the partition wall 4242 includes a flow guide 4246 disposed distally of the wall portion 276, and a deformation panel 294 disposed distally of the flow guide 4246. The deformation panel 294 is the same as the deformation panel 294 described above with respect to the cushion module 20, and operates in the same manner in terms of controlled collapse under the influence of a deformation force applied to the wall portion 276. This means that the deformation panel 294 of the cushion module 4020 is configured to deform in preference to the flow guide 4246 and the main portion 244. The partition wall 4242 includes an outer portion 800 disposed laterally outward of the flow guide 4246 and joining the outer wall 288. The outer portion 800 is proximal to the deformation region. In this embodiment, the deformation region is configured to deform in preference to the outer portion 800 as well. As shown in FIG. 36, the outer portion 800 joins the outer wall 288 at a position spaced apart from the top of the outer wall 288. In this particular embodiment, the height of outer portion 800 where it joins with outer wall 288 is significantly below the height of the top of outer wall 288. More specifically, outer portion 800 joins outer wall 288 along a line (i.e., abutment line 4282) that extends at least partially above and partially below the lowest point of the nostril openings 234, taking into account the upright orientation of the patient interface 10, and which does not extend above the highest point of the nostril openings 234.

[0570] However, in another embodiment, the outer portion 800 may join the outer wall 288 at a height below the lowest point of the nostril openings 234. In a further embodiment, a portion of the outer portion 800 joins the outer wall 288 along a line that extends between the highest and lowest points of the nostril openings 234 and does not extend above the highest point of the nostril openings 234, taking into account the upright orientation of the patient interface 10. In a further alternative embodiment, a portion of the outer portion 800 joins the outer wall 288 along a line that extends above the highest point of the nostril openings 234, taking into account the upright orientation of the patient interface 10. In another alternative embodiment, the outer portion 800 joins the outer wall 288 at a height that is lower or substantially equal to the highest point of the flow director 4246, taking into account the upright orientation of the patient interface 10.

[0571] As a result of the flatter transverse profile of the partition wall, the inclination of the outer portion 800 joining the outer wall 288 is horizontal or at an acute angle to the horizontal plane, taking into account the upright orientation of the patient interface 10. More specifically, the inclination of the outer portion 800 joining the outer wall 288 is less than 45°, less than 30° or less than 15° to the horizontal plane, taking into account the upright orientation of the patient interface 10. In most embodiments, the outer portion 800 joins the outer wall 288 to form an obtuse angle with the inner surface of the outer wall in the second chamber 240.

[0572] The seal member 4230 includes a reinforcing portion 804 (FIG. 36) that resists deformation of the seal member 4230 and thereby helps to maintain the shape of the seal member 4230. The reinforcing portion 804 includes a portion having a wall thickness greater than the wall thickness of the remaining portions of the outer wall 288. The outer portion 800 joins, at least in part, with the reinforcing portion 804 of the outer wall 288 that has a wall thickness greater than the wall thickness of the patient-contacting surface 290 of the outer wall 288. For example, the outer portion 800 joins with the reinforcing portion 804 of the seal member 4230 that is overmolded with the housing 210. Joining the outer portion 800 with this overmolded reinforcing portion 804 of the seal member 4230 helps to maintain the shape of the partition wall 4242 by transferring deformation forces applied to the patient-contacting surface 290 to the reinforcing portion 804, such as the overmolded reinforcing portion 804 of the seal member 4230.

[0573] As with the other embodiments, the cushion module 4020 defines an interior volume including a first chamber 238 and a second chamber 240. The second chamber 240 is located in an upper portion of the interior volume of the seal member 4230. The first resilient region 268 is positioned at a height that is higher than or equal to the biased vent 226, taking into account the upright orientation of the patient interface 10. The partition wall 4242 joins the wall portion 276 approximately halfway between the nasal openings 234 and the oral opening 232. Alternatively, the partition wall 4242 may join the wall portion 276 in the upper half of the wall portion 276.

[0574] 34-40 show flow directors 4246. The flow directors 4246 allow gas flow between the first chamber 238 and the second chamber 240. Each flow director 4246 has a base 806 joining the partition wall 4242 and defining a first opening 4250 into the first chamber 238, a body 4248 extending from the base 806, and a rim 4254 distal from the base 806. The rim 4254 defines a second opening 4252 that opens into the second chamber 240. As with the other embodiments, the gas flow channel 812 extends from the first opening 4250 in the base 806 to the second opening 4252 in the rim 4254.

[0575] While this and other embodiments show the body 4248 extending from the partition wall 4242 into the second chamber 240, it will be understood that other configurations of the flow director 4246 may be employed. One example of such a configuration includes the body 4248 extending at least partially into the first chamber 238. In other words, the body 4248 extends partially downward from the partition wall 4242 into the first chamber 238 and partially upward from the partition wall 4242 into the second chamber 240. The base 806, in this configuration, joins the body 4248 to the partition wall 4242. It has an annular form from which a lower body portion 4256 extends into the first chamber 238. The lower body portion 4256 includes the first opening 4250 of the first chamber. The upper body portion 4258 extends from the base 806 into the second chamber 240 and includes a second opening 4252. This configuration can be combined with any of the features described in the above and subsequent embodiments. In another embodiment, the flow director 4246 does not need to extend from both sides of the partition wall 4242. For example, the partition wall 4242 can have a wall thickness sufficient to include the flow director 4246 between the surfaces of the partition wall 4242 exposed to the first chamber 238 and the second chamber 240, respectively.

[0576] 34, 35 and 39 show that the body 4248 of each flow director 4246 includes a transition portion intermediate the base 806 and the rim 4254. The transition portion 802 delineates the lower body portion 4256 from the upper body portion 4258. The lower body portion 4256 extends from the base to the transition portion. The upper body portion extends from the transition portion to the rim 4254. In this embodiment, the transition portion includes, at least in part, a step 802, where the upper body portion 4258 extends from the step 802 to the rim 4254. The step 802 is formed outside the flow director 4246. The upper body portion 4258 has a wall thickness that is less than the wall thickness of the lower body portion 4256. Thus, the step 802 joins the different wall thicknesses of the upper body portion 4258 and the lower body portion 4256. The step 802 extends around the entire circumference of the flow director 4246. Thus, there is a step change in the wall thickness of the flow director 4246 from the lower body portion 4256 to the upper body portion 4258. The step change in the wall thickness of the flow director 4246 occurs at the outer surface of the flow director 4246 while the inner surface of the flow director 4246 is smooth. The upper body portion 4258 extends from the step 802. The upper body portion 4258 terminates at a rim 4254 spaced apart from the nostril opening 234. The upper body portion 4258 has a wall thickness that is less than the wall thickness of the lower body portion 4256. The thinner wall thickness of the upper body portion 4258 allows the upper body portion 4258 to easily deform and therefore reduces discomfort to the patient when the upper body portion 4258 contacts the patient's nose. The greater wall thickness of the lower body portion 4256 increases the resistance of the flow director 4246 to collapsing or buckling under the influence of a deformation force. The wall thickness is selected to increase the resistance to deformation such that a deformation force applied to the wall portion 276 is transferred through the partition wall 4242 about the flow director 4246 and into the deformation panel 294. In this manner, the deformation panel 294 deforms in preference to the flow director 4246, and therefore the flow director 4246 is more likely to retain its shape and ability to transfer a desired flow rate of gas between the first chamber 238 and the second chamber 240 when a deformation force is applied.In other words, the flow director 4246 is less likely to clog when subjected to a deforming force.

[0577] As shown in Figures 35 and 36, the step 802 is inclined relative to the partition wall 4242. The step 802 is further from the partition wall 4242 distal to the flow director 4246 and closer to the partition wall 4242 proximal to the flow director 4246. Furthermore, the step 802 also inclines downward in a lateral inward direction towards a vertical mid-plane through the patient interface 10, taking into account the upright orientation of the patient interface 10. This means that the step 802 is further from the partition wall 4242 laterally outer of the flow director 4246 than from the partition wall 4242 laterally inner of the flow director 4246. The lateral and proximal inclination of the step 802 provides a substantially constant spacing between the step 802 and the nostril opening 234.

[0578] The upper body portion 4258 extends from the step 802 a constant distance around the flow director 4246. This means that the rim 4254 has the same slope as the step. That is, the rim 4254, and therefore the second opening 4252, has a slope that provides a substantially constant spacing between the rim 4254 and the nostril opening 234. However, compared to other previously disclosed embodiments, the rim 4254 is set back further from the nostril opening 234. The increased setback further facilitates the flow of gas from the first chamber 238 to the second chamber 240, such as respiratory gas exhaled by the patient through the mouth. The flow of gas from the nostrils to the second chamber 240 through the nostril opening 234, such as respiratory gas exhaled through the patient's nostrils, is also facilitated.

[0579] In the illustrated embodiment, the step 802 extends substantially all the way around the flow director 4246. However, the transition may include the step 802 in only a portion of the flow director 4246. For example, in some embodiments, the step 802 may extend around at least a distal side of the flow director 4246. In other embodiments, the step 802 may extend around a distal side and laterally outward of the flow director 4246.

[0580] In this embodiment, the radial wall thickness of the lower body portion 4256 is constant circumferentially around the flow director 4246. The radial wall thickness of the upper body portion 4258 is also constant circumferentially around the flow director 4246. This means that the step 802 has a constant wall thickness change around the flow director 4246 from the lower body portion 4256 to the upper body portion 4258. However, in other embodiments, the radial wall thickness of the lower body portion 4256 may vary around the flow director 4246, taking into account the longitudinal axis of the flow director 4246. In further embodiments, the radial wall thickness of the lower body portion 4256 may vary circumferentially around the flow director 4246. Alternatively, the radial wall thickness of the lower body portion 4256 may vary depending on the spacing of the rim 4254 from the base 806. For example, the radial wall thickness of the lower body portion 4256 may be greater where the rim 4254 is spaced farther from the base 806 than where the rim 4254 is spaced farther from the base 806. As another example, the radial wall thickness of the lower body portion 4256 is smallest where the spacing between the rim 4254 and the base 806 is smallest, and the radial wall thickness increases as the spacing between the rim 4254 and the base 806 increases. The reduced radial wall thickness of the upper body portion 4258 relative to the lower body portion 4256 makes the upper body portion 4258 more compliant and therefore reduces the discomfort experienced by the patient when the nose comes into contact with the upper body portion 4258.

[0581] The divider wall 4242 further includes a spacer rib 4260 disposed between the bodies 4248 of the flow directors 4246, as shown in FIGS. 34-36. The spacer rib 4260 joins the bodies 4248 at a location spaced apart from the rim 4254. In this embodiment, the spacer rib 4260 extends from the divider wall 4242 between the flow directors 4246 and joins the base 806, the lower body portion 4256, the stepped portion 802 and the upper body portion 4258, but is spaced apart from the rim 4254. By spacing the spacer rib 4260 away from the rim 4254, and thus further away from the nostril openings than the rim 4254 is from the nostril openings, the likelihood of the patient's nose contacting the spacer rib 4254 during use is reduced. The spacer rib 4260 is disposed in a plane that intersects the longitudinal axis of the flow directors 4246. Thus, the spacer rib 4260 is disposed intermediate the proximal and distal sides of the flow director 4246 .

[0582] 35, the spacer ribs 4260 have an inverted U-shaped profile. The spacer ribs 4260 stiffen the flow director 4246 making it more resilient against buckling inwardly or outwardly. Reducing the likelihood of buckling helps to maintain alignment of the flow director 246 in a direction that directs the flow of breathing gas towards the nostril openings 234 when in use. Furthermore, the location of the spacer ribs 4260 and the stiffening sections 4264 means that deflections of the wall portion 276 are transferred through the spacer ribs 4260 and the stiffening sections 4264, thus causing the flow director 4246 to follow the movements of the wall portion 276 and the nostril openings 234.

[0583] The spacer rib 4260 has a generally upright orientation, taking into account the upright orientation of the patient interface 10. Taking into account that the partition wall 4242 slopes downwardly from the wall portion 276 towards the modified panel 294, the spacer rib 4260 is sloped relative to the partition wall 4242. That is, the spacer rib 4260 joins the partition wall 4242 at an acute angle on its proximal side. The spacer rib 4260 includes a fillet-shaped transition joint with the flow director 4246. This provides a smooth transition 802 from the spacer rib 4260 to the base 806 and to the body 4248 of the flow director 4246.

[0584] The thickness of the spacer ribs 4260 in the distal-proximal direction is significantly greater than the wall thickness of the flow director 4246. More specifically, the spacer ribs 4260 have a wall thickness in the distal-proximal direction that is 5-20%, 20-40%, or 40-60% of the maximum width dimension of the flow director 4246.

[0585] The spacer rib 4260 (FIGS. 35, 36 and 38) overlaps a reinforcing section 4264 located on the underside of the partition wall 4242 between the first openings 4250 of each of the flow directors 4246. The reinforcing section 4264 comprises a thickened section of the partition wall 4242. The reinforcing section 4264 extends in a distal-proximal direction. It is further located at a distance from the wall portion 276 and from the deformation panel 294. The reinforcing section 4264 increases the stiffness of the partition wall 4242 in the region between the wall portion 276 and the deformation panel 294, and thus contributes to transmitting deformation forces applied to the wall portion 276 around the flow directors 4246 to the deformation panel 294. The reinforcing section 4264 thus helps to maintain the position of the partition wall 4242 (and the flow directors 4246) relative to the nostril openings 234. In other words, the reinforcement section 4264 helps to secure the divider wall in place relative to the wall portion 276. This allows patient treatment to continue with little or no obstruction to the flow of respiratory gas (a) through the flow directors 4246, (b) through the nostril openings 234, and (c) through the second chamber 240 during deformation of the patient-contacting surface 290 of the outer wall 288.

[0586] The reinforcement section 4264 helps transfer deformation forces from the wall portion 276 to the deformation panel 294 by portions 808, 810 of the partition wall 4242 having a wall thickness greater than the wall thickness of other portions of the partition wall 4242. The portions 808, 810 are proximal and distal, respectively, of the flow director 4246. In some embodiments, the proximal and distal portions 808, 810 are proximal and distal, respectively, of the spacer rib 4260. In some embodiments, the proximal and distal portions 808, 810 comprise respective portions of the partition wall 4242 that are proximal and distal, respectively, of the flow director 4246. The proximal portion 808 is between the outer portions 800 of the partition wall 4242. Alternatively, the proximal portion may be between the flow directors 4246. The distal portion 810 is between the outer portions 800 of the partition wall 4242. For embodiments not including the spacer rib 4260, the proximal portion 808 and the distal portion 810 are respectively proximal and distal to an imaginary line passing through the center of each second opening 4252 of the flow director 4246. The wall thickness of the distal portion is represented by the wall thickness excluding the wall thickness of the reinforcement section 4264. FIG. 36 shows the distal portion 810 having a wall thickness greater than the wall thickness of the outer portion 800. The distal portion 810 extends from the spacer rib 4260 and around the base 806 of the flow director 4246. The distal portion 810 also extends towards the deflection panel, but is spaced apart from the second wall 272 of the deflection panel 294. Thus, the distal portion 810 overlaps the reinforcement section 4264. The same applies to the proximal portion 808, as shown in FIG. 35 and FIG. 38. The proximal portion 808 joins the spacer rib 4260 and overlaps the reinforcement section 264. The proximal portion 808 extends proximally from the spacer rib 4260 and around the base 806 of the flow director 4246. The proximal portion 808 joins the wall portion 276.

[0587] These portions 808, 810 have a greater resistance to deformation due to their greater wall thickness compared to the rest of the partition wall. As a result, deformation forces applied to the wall portion 276 are transferred through the partition wall 4242 to the deformation panel 294, which deforms in preference to the portions 808, 810. The presence of the portions 808, 810 together with the reinforcement section 276 and the spacer ribs 4260 prevents undesired deformation of the partition wall 4242 by improving the transfer of deformation forces to the deformation panel 294. Thus, the likelihood of the flow director 4246 collapsing or buckling due to buckling of the partition wall 4242 is reduced. However, there is a limit to the wall thickness of the portions 808, 810, since increasing the wall thickness of the portions 808, 810 has the effect of localizing the pressure experienced by the patient to the wall portion 276. In other words, increasing the wall thickness of the portions increases the likelihood of bed sores. Conversely, if the wall thickness is made too thin, the deformation force will not be transmitted to the deformation panel 294, which may result in buckling of the partition wall 4242 as well as buckling of the flow guide portion 4246.

[0588] The increased wall thickness of portions 808, 810 means that the reinforcement section 4264 does not have to extend all the way to the wall portion 276 or all the way to the deformation panel 294 in order to transfer deformation forces from the wall portion 276 into the deformation panel 294.

[0589] The resistance to flow through the flow director 4246 is reduced by employing a larger first opening 4250 and a larger second opening 4252 compared to the flow director 246 of the cushion module 20. A comparison of the first opening 250 of the cushion module 20 in FIG. 11 with the first opening 4250 of the cushion module 4020 in FIG. 40 provides an example of the difference in size between the flow director 4246 and the flow director 246. To accommodate the larger size of the first opening 4250, the shape and orientation of the first opening 4250 is different to allow the flow director 4246 to fit between the wall portion 276 and the modified panel 294. The employed shape shown in FIG. 40 allows the flow director 4246 to be spaced apart from the wall portion 276 and the modified panel 294. This reduces the extent to which the wall portion 276 is stiffened by the base 806. Stiffening of the wall portion 276 can reduce patient comfort by forming localized pressure points that can lead to patient pain over a period of time. Locating the flow director 4246 away from the deflection panel 294 provides additional displacement travel for the deflection panel 204 to deform and thereby absorb deformation forces. That is, limiting the range of travel of the deflection panel 294 limits the degree of deformation forces that the divider wall 4242 or other features of the seal member 4230, such as the flow director 4246, can absorb before they begin to buckle under the forces. Such uncontrolled buckling is undesirable as it can cause the flow director to misalign with the nostril openings, impede gas flow through the flow director, or even occlude gas flow through the flow director.

[0590] As shown in FIG. 40, the first openings 4250 have a shape in which the major axis U1 is longer than the orthogonal minor axis U2. In this embodiment, the first openings 4250 have an elliptical shape. However, it will be appreciated that an alternative shape having a major axis U1 and an orthogonal minor axis U2 may be employed instead of an elliptical shape. To aid in the fit of the first openings 4250 between the wall portion 276 and the modified panel 294, the major axis U1 is in the plane of the partition wall 4242 and is oriented at least 45° from a vertical mid-plane through the patient interface 10. Thus, the dimension of the first openings in the proximal-distal direction is reduced compared to if the major axis U1 were parallel to the vertical mid-plane. In the embodiment shown in FIG. 40, the major axis U1 of each first opening 4250 intersects at a point proximal to an imaginary line 814 (FIG. 40) passing through the center of the first opening 4250. In some embodiments, the longitudinal axes U1 of each first opening 4250 may intersect at a point proximal to the patient contacting portion 290 of the outer wall 288. In either case, the angle (V) between the longitudinal axes U1 where they intersect is less than 180°. The angle V may be in the range of 45° to less than 180°, in the range of 90° to 150°, or in the range of 110° to 150°. In other embodiments, the longitudinal axes U1 of each first opening 4250 may intersect at a point distal to a line passing through the centers of the first openings 4250. In this alternative, the angle V between the longitudinal axes U1 will be within the ranges as described above.

[0591] The orientation of the major axis U1 and the minor axis U2 is maintained throughout the flow director 4246. However, the dimensions of the flow director 4246 along the major axis U1 and the minor axis U2 at the second opening 4252 are different from the dimensions of the flow director 4246 along the major axis U1 and the minor axis U2 at the first opening 4250. Specifically, in this embodiment, the dimensions of the flow director 4246 along both the major axis U1 and the minor axis U2 at the second opening 4252 are smaller than the dimensions of the flow director 4246 along the respective major axis U1 and minor axis U2 at the first opening 4250. In other embodiments, the orientation of the major axis U1 and the minor axis U2 at the second opening 4252 is different from the orientation of the major axis U1 and the minor axis U2 at the first opening 4250. Alternatively, the orientation of the major axis U1 and the minor axis U2 may change throughout the flow director 4246 from the first opening 4250 to the second opening 4252. In other embodiments, the dimensions of the flow director 4246 along one of the major axis U1 or the minor axis U2 at the second opening 4252 may be different than the dimensions of the flow director 4246 along the corresponding axis at the first opening 4250. For example, the dimensions of the flow director 4246 along only one of the major axis U1 or the minor axis U2 at the second opening 4252 are smaller than the dimensions of the flow director 4246 along the corresponding axis at the first opening 4250. Alternatively, the dimensions of the flow director 4246 along the major axis U1 or the minor axis U2, or both the major axis U1 and the minor axis U2, vary through the flow director 4246 from the first opening 4250 to the second opening 4252. In other embodiments, the orientation and dimensions of the flow director 4246 along the major axis U1 and the minor axis U2 at the second opening 4252 are different than the orientation and dimensions of the flow director 4246 along the major axis U1 and the minor axis U2 at the first opening 4250.

[0592] The positioning of the second openings 4252 relative to a vertical mid-plane through the patient interface 10 is selected to direct gas flowing from the first chamber 238 to the second chamber 240 through the nostril openings 234 and into the patient's nares. However, if the second openings 4252 are positioned too close together, there is a risk that the gas flow may be directed into the patient's nasal septum. This may cause patient discomfort, undesirable turbulence, and problems delivering sufficient flow rate to the nares. Therefore, the second openings 4252 are positioned far enough apart to direct the gas flow into the nares while substantially avoiding directing the gas flow into the patient's nasal septum. In this embodiment, the orientation of the major axis U1 and the minor axis U2 and the spacing of the second openings 4252 cause the outer wall 288 to extend over a portion of the second openings 4252 when the patient interface 10 is not attached to a patient. 32 and 40, where, when the patient interface 10 is not attached, the laterally outer portions of the rims 286 of the nostril openings 234 extend over a portion of each second opening 4252. That is, a portion of the outer wall 288 surrounding the nostril openings 234 extends beyond the laterally outer portions of the respective second openings 4252 when viewed vertically from above the cushion module 4020, taking into account the upright orientation of the cushion module 4020.

[0593] In the view shown in FIG. 32, when the patient interface 10 is viewed vertically above the midpoint between the second openings 4252, taking into account the upright orientation of the patient interface 10 when not attached, at least a portion of each second opening 4252 is hidden by the outer wall 288. However, the outer wall 288 is configured to allow the nostril openings 234 to expand laterally outward when attached to a patient. This is primarily due to the nostril sealing portion 236 being curved to receive the underside of the patient's nose when the patient interface 10 is attached to a patient, thereby reducing the curvature when the patient interface 10 is attached. However, this is facilitated by the outer wall 288 being formed from a resilient material. The nostril sealing portion 236 has a relatively thin wall thickness compared to the rest of the outer wall 288, and therefore the resilient material forming the outer wall 288 allows the nostril openings 234 to expand laterally outward when attached to a patient. In other words, the patient contacting surface 290 includes a valley shaped nostril sealing portion 236 configured to receive the underside of the patient's nose. The floor of the valley shape, including the nostril opening 234, assumes a flatter valley shape when the patient interface 10 is attached to the patient. As a result, when the patient interface 10 is attached to the patient, the laterally outer edge of the nostril opening 234 is displaced laterally outward of the second opening 4252. As a result, when the patient interface 10 is attached, the gas stream through the flow director 4246 is directed through the nostril opening 234 without impinging on the outer wall 288.

[0594] The curvature of the outer wall 288, and the fact that the outer wall is made from a resilient material, contributes to a change in area, shape, or shape and area of ​​the nasal openings 234 when the patient interface 10 is attached to a patient. This change allows the gas stream passing through the flow director to be directed through the nasal openings 234 without impinging on the outer wall 288.

[0595] Instead of the flow directors, spacer ribs, reinforcing sections, distal and proximal portions described above for the cushion module 4020, alternative forms of flow directors, spacer ribs, reinforcing sections, distal and proximal portions can be utilized. Several alternative embodiments of these components are discussed below. It will be appreciated that different alternative embodiments may be combined in the cushion module 4020. For example, in the cushion module 4020, any one of the alternative flow directors 246, 1246, 2246, 3246 and 4246 discussed above, or any one of the flow directors 820, 830, 840, 850, 860, 870, 880 or 890 discussed below, may be combined with any one of the range of alternative spacer ribs 260, 1260 discussed above, or any one of the spacer ribs 828, 838, 848, 888, 898 discussed below.

[0596] Features of the following embodiments that are the same as features of the cushion module 4020 are designated with the same reference numbers.

[0597] An alternative flow director 820 is shown in FIG. 41. The flow director 820 has the same general form as the flow director 4246 in that it includes a base 821, a body 822 extending from the base 821, and a rim 823. The base 821 joins the body 822 to the partition wall 4242. The base 821 forms a smooth transition between the body 822 and the partition wall 4242. As with the flow director 4246, a portion of the outer wall 288 extends over a laterally outer side of the second opening 824 defined by the rim 823. This is shown in FIG. 42. As described above with respect to the cushion module 4020, when the patient interface 10 is attached, the nostril openings 234 expand laterally such that the nostril openings 234 expand laterally outwardly such that the outer wall 288 does not extend over the second opening 824.

[0598] The flow director 820 differs from the flow director 4246 in that it has a differently shaped body 822 and differently shaped spacer ribs 828. The body 822 includes a transition section 825 that delineates a lower body section 826 from an upper body section 827. The lower body section 826 has a wall thickness that decreases from the base 821 to the transition section 825. The upper body section 827 has the same wall thickness from the transition section to the rim 823. The lower body section 826 is angled proximally such that the proximal side of the lower body section 826 that extends from the base 821 to the transition section 825 is shorter than the distal side of the lower wall section 826 that extends from the base 821 to the transition section 825. The upper body section 827 is angled proximally and laterally inward. In other words, the rim 823 is angled such that it is positioned further away from the laterally outer, distal partition wall 4242 of the flow director than it is positioned from the laterally inner, proximal partition wall 4242 of the flow director 4246. The transition portion 825 occupies a similarly angled plane as the lower body portion 826. The same angular orientation is present in the flow director 4246. The angling of the lower and upper body portions 826, 827 and the lateral positioning of the flow director 820 promotes the direction of breathing gas from the flow director 820 to the nostril through one of more nostril openings.

[0599] The bases 821 of each of the flow directors are joined via the cushion modules 4020 (as seen in FIG. 42 ) at a vertical mid-plane. Spacer ribs 828 span the gaps between the flow directors 820. The spacer ribs 828 extend from the bases 821 of each flow director 820 to the transition section 825. The tops of the spacer ribs 828 form straight lines between the flow directors 820. The spacer ribs 828 overlap the underside reinforcement section 4264 of the partition wall 4242. The proximal and distal portions 808 and 810 of the partition wall 4242 have the same wall thickness as the wall thickness of the outer portion 800.

[0600] FIG. 43 illustrates another alternative flow director 830. The flow director 830 has the same general configuration as the flow director 820 in that it has a base 831, a body 832, and a rim 833. The body includes a transition section 835 that delineates a lower body section 836 from an upper body section 837. The flow director 830 differs, however, in that the lower body section 836 has a substantially constant wall thickness from the base to the transition section. The transition section 835 slopes proximally to abut the base 831 proximally of the body 832. In another embodiment, the transition section 835 joins the base 831 proximally of the body 832. The slope of the transition section 825 means that the lower body section 836 proximal to the body 832 exerts less pressure on the wall section 276 when the wall section 276 is pressed against the flow director 830.

[0601] The wall thickness of upper body portion 837 tapers inwardly from transition 835 to rim 833. This is shown in cross section in Figure 44. In this particular embodiment, the outer wall of body 832 tapers inwardly towards the inner wall of body 832. This gives body 832 a curved exterior profile.

[0602] Flow director 830 includes spacer ribs 838 that are the same size and shape as spacer ribs 828 of flow director 820. However, transition portion 835 is lower on body 832 than transition portion 825 on body 822, such that spacer ribs 838 extend from base 831 to a point between transition portion 835 and rim 833.

[0603] FIG. 45 illustrates a further alternative flow director 840. The flow director 840 has the same general configuration as the flow director 820 in that it has a base 841, a body 842, and a rim 843. The body 842 includes a transition portion 845 that delineates a lower body portion 846 from an upper body portion 847. The transition portion 845 includes, in part, a step 844 intermediate the base 841 and the rim 843. However, the step 844 joins the upper body portion 847 to the base 841 proximal to the body 842 due to the inclination of the step 844. The proximal side of the flow director 840 is laterally proximal to an imaginary centerline. The lower body portion 846 below the step 844 has a first wall thickness, and the upper body portion 847 above the step 844 has a second wall thickness. The first wall thickness may vary around the circumference of the lower body portion 846. The second wall thickness is less than the first wall thickness. The greater wall thickness of the lower body portion 846 provides resistance to deformation of the flow director 840 when a deformation force is applied to the wall portion 276. The resistance to deformation helps direct the deformation force applied to the wall portion 276 through the divider wall and towards the deformation panel 294. The smaller wall thickness of the upper body portion 847 makes the upper body portion 847 more compliant and softer to the touch when the rim 843 contacts the patient.

[0604] Considering the longitudinal axis of the flow director 840, the radial wall thickness of the upper body portion 847 is constant around the flow director 840. However, the radial wall thickness of the lower body portion 846 varies around the flow director. In this embodiment, the radial wall thickness of the lower body portion 846 varies as a function of the spacing of the rim 843 from the base 841. More specifically, the radial wall thickness of the lower body portion 846 is greater where the rim 843 is more spaced from the base 841 than where the rim 843 is less spaced from the base 841. In this embodiment, the wall thickness distal to the lower body portion 846 is greater than the wall thickness proximal to the lower body portion 846. In one alternative embodiment, the radial wall thickness of the lower body portion 846 is smallest where the spacing between the rim 843 and the base 841 is smallest and increases as the spacing between the rim 843 and the base 841 increases. In another alternative embodiment, the wall thickness of the lower body portion 846 is constant around the flow director 840 .

[0605] The step 844 extends around at least the distal side of the flow director 840. As seen in FIG. 45, the step 844 includes a sloped surface that joins the lower body portion 846 to the upper body portion 847. The slope of the step 844 varies around the circumference of the flow director 840. More specifically, the slope is steeper proximal to the body 842 and less steep distal to the body 842. As a result, the profile of the step 844 varies depending on the position around the body 842. This can be seen in FIG. 45, where the proximal side of the body 842 has a steeper step 844 and the distal side of the body 842 has a less steep step 844. In this particular embodiment, the step 844 extends all the way around the body 842 and joins the base 841 to the upper body portion 847 proximal to the flow director 840.

[0606] The spacer ribs 828 and 838 associated with the flow directors 820 and 830, respectively, are identical. However, the spacer ribs 848 associated with the flow directors 840 have a square or rounded square cross-sectional profile. The spacer ribs extend from the partition wall 4242 and fill the gaps between the flow directors 840. The spacer ribs 848 extend above the base 841 and the lower body portion 846 to the step 844. That is, the spacer ribs 848 terminate at the top of the lower body portion 846 where the spacer ribs 844 abut the step 844. The top surface of the spacer ribs 848 is flattened and sloped such that the distal side of the spacer ribs 848 extends further from the partition wall 4242 than the proximal side of the spacer ribs 848 extends from the partition wall 4242. The slope of the spacer ribs 848 follows the proximal-distal slope of the step 844 where the spacer ribs 848 abut the step 844 .

[0607] Figure 47 shows an alternative embodiment of a spacer rib 848 along with the same flow director 840. In this embodiment, the spacer rib 848 is the same as the spacer rib shown in Figure 45, but joins the base 841, the lower body portion 846, and the stepped portion 844. As can be seen in Figure 47, the spacer rib 848 includes a fillet-shaped transition joint with the flow director 840.

[0608] As in the other embodiments, the spacer ribs 848 overlap the reinforcement sections 849. This arrangement contributes to transmitting deformation forces applied to the wall portion 276 to the deformation panel 294. In the above-described embodiment, the same configuration is also present for the flow directors 820, 830. They are associated with the same reinforcement sections 4264 as are present in the cushion module 4020. However, the effect is the same in that deformation forces are transmitted by the respective lower body portions 826, 836 to the associated spacer ribs 828, 838 and then through the reinforcement sections 4264 to the deformation panel 294.

[0609] However, an embodiment of the flow director 840 has an alternative reinforcement section 849. FIG. 48 shows that the reinforcement section 849 has the same elongated shape as the reinforcement section 4264, but the reinforcement section 849 extends from under the spacer rib 848 to the deformation panel 294. This differs from the reinforcement section 4264, which extends from the spacer rib 4262 to a location spaced apart from the deformation panel 294. Having the reinforcement section 849 extend to the deformation panel 294 can help control deformation of the deformation panel 294. More specifically, the reinforcement section 849 promotes a rolling action of the second wall 272 below the first resilient section 268.

[0610] The embodiments of the flow directors 820, 830 and 840 are associated with a proximal portion 808 and a distal portion 810 of the partition wall 4242 having the same wall thickness as the wall thickness of the outer portion 800. The wall thickness of the proximal portion 808 and the distal portion 810 may be different in different embodiments. For example, Figs. 52-54 show a flow director 4246 with associated spacer ribs 4260 as described above with respect to the cushion module 4020. These figures also show different embodiments with different wall thicknesses of the proximal portion 808 and the distal portion 810. In comparison with the flow directors 820, 830 and 840, Figs. 50 and 51 show a flow director 4246 with spacer ribs 828 and with the proximal portion 808 and the distal portion 810 having the same wall thickness as the outer portion 800. The proximal portion 808 is thickened in the embodiment shown in Fig. 52. This thickening of the proximal portion 808 increases the resistance of the proximal portion 808 to deformation, thereby improving the stability of the flow director 4246. The improved stability occurs because deformation forces are directed through the proximal portion 808 and into the reinforced section 4264. This promotes a controlled deformation of the deformation panel 294 instead of buckling of the proximal portion 808, which can cause the flow director 4246 to buckle or collapse.

[0611] Figure 53 shows a variation of the embodiment shown in Figure 52 with the same flow director 4246 and the same spacer ribs 4260. This embodiment differs in that the proximal portion 808 is thickened further compared to the proximal portion 808 shown in Figure 52. It also differs in that the distal portion 810 is thickened compared to the distal portion 810 shown in Figure 52. The thickening of the proximal portion 808 and distal portion 810 has the same effect of improving the stability of the flow director 4246 as described above for the embodiment shown in Figure 52.

[0612] 54 and 55 show a further variation of the embodiment shown in FIG. 52 with the same flow directors 4246 and the same spacer ribs 4260. In this embodiment, the distal portion 810 is thickened similarly to the embodiment shown in FIG. 53. This embodiment differs in that the proximal portion 808 has the same wall thickness as the wall thickness of the outer portion 800 in the region proximal to the spacer ribs 4260. The proximal portion 808 includes a brace member 818 disposed between each flow director 4246 and the outer wall 288. The brace member 818 maintains the spacing between the outer wall 288 and each of the respective flow directors 4246.

[0613] Each brace member 818 is joined to the outer wall 288 at a portion of the outer wall between the nasal openings 234 and the oral opening 232. In this embodiment, each brace member 818 is joined only to the base 806 and the lower body portion 4256 (FIG. 54). In other embodiments, the brace members 818 may be joined to the base 806, the lower body portion 4256, and the stepped portion 802. In further embodiments, the brace members 818 may be joined only to the base 806. In each of these embodiments, the brace members can have a lateral width that is 20-70% of the lateral width of the flow director 4246.

[0614] In this embodiment, the brace member 818 has a trapezoidal profile. However, the base member is not limited to this profile. For example, the brace member 818 may have a polygonal profile, a semicircular profile, a circle segment profile, or a curved profile.

[0615] 56 and 57 show an alternative embodiment of a flow director 850 for the cushion module 4020. The flow director 850 has some of the same general form as the flow director 820 in that it has a base 851, a body 852, and a rim 853. The base 851 includes a laterally outwardly directed thickened pad 854 that decreases in thickness from the body 852 to the lateral outermost portion of the base 851. The base 851 wraps around the body 852 at a height where the thickened pad 854 joins the body 852. The body 852 extends upwardly from the base 851 and terminates at the rim 853.

[0616] In other words, the base 851 of each flow director 850 is elongated laterally away from a vertical mid-plane through the patient interface 10, taking into account the upright orientation of the patient interface 10. Furthermore, the body 852 is offset from a lateral centerline (shown as Z in FIG. 57) through the base 851 such that the body 852 is closer to the laterally inner side of the base 851 than to the laterally outer side of the base 851. The laterally outer side of the base 851 extends further laterally outward from the body 852 than the laterally inner side of the base 851 extends laterally inward from the body 852. This is evident in FIG. 57, which shows that the gas flow channels 812 are offset laterally inward from a lateral centerline through the base 851, which is parallel to a vertical mid-plane through the patient interface 10. Thus, the gas flow channels 812 are closer to the laterally inner side of the base 851 than to the laterally outer side of the base 851. In this embodiment, the base 851 has a footprint that extends laterally beyond the corresponding lateral edges of the nostril openings 234. However, the laterally outer side of the base 851 may extend different distances in different embodiments. In that regard, the laterally outer side of the base 851 extends laterally outward from the body 851 at least two times, at least three times, at least four times, or at least five times the distance that the laterally inner side of the base 851 extends laterally inward from the body 851.

[0617] The effect of the thickened pad 854 is to stabilize the body 852. More specifically, the thickened pad 854 increases the resistance of the flow director 850 to buckling or collapsing, since localized buckling of the divider wall 4242 is prevented. This improves the lateral stability of the flow director 850 and helps resist inward deflection of the flow directors 850 towards each other. As a result, the thickened pad helps maintain the orientation of the flow directors 850 as they direct breathing gases through the nasal openings 234 and into the patient's nares during use.

[0618] A further factor contributing to resistance to buckling or collapsing of the flow director is an increased wall thickness of the body 852. For patient comfort reasons, the wall thickness of the body 852 cannot be too thick as it would cause discomfort to the patient when the body 852 comes into contact with the patient. Alternatively, the body 852 may include a transition section and upper and lower body portions in the form of any one of the bodies 248, 1248, 2248, 3248, 822, 832 or 842. In these alternative forms, the transition section may take the form of a step 802. In these alternative embodiments, the step may extend all or part of the way around the body.

[0619] Another feature that may be employed in any of the embodiments disclosed herein is a reinforcing segment 855 (FIG. 56) on the body 852, or on the body of any of the other embodiments. The reinforcing segment 855 comprises a rib in this embodiment. The reinforcing segment 855 in the form of a rib or the like may be used in combination with other features disclosed herein to stabilize the flow director and transfer deformation forces to the deformation region. It will thus be understood that the reinforcing segment 855 is not exclusive to this embodiment and may be used in combination with other flow directors, such as the flow directors 246, 1246, 2246, 3246, 820, 830, 840, and the flow directors 860 and 870, 880 or 890 (described below).

[0620] 56 and 57 are configured to resist deformation of the shape of the second opening 856 under a deformation force. The reinforcement segment 855 may extend all the way around the body 852 or partially around it. In this embodiment, the reinforcement segment 855 extends partially around the body 852 at a distal side of the body 852. However, in other embodiments, the reinforcement segment 855 may extend around the distal side of the body 852, the proximal side of the body 852, or an outer side of the body 852, or a combination thereof (e.g., the proximal and lateral sides, or the lateral and distal sides).

[0621] The reinforcing segment 852, in this embodiment, is integrally formed with the body 852. It has a wall thickness that is greater than the wall thickness of the remainder of the body 852. In another embodiment, the body 852 is formed of a first material and the reinforcing segment 855 is formed of a second material that is different from the first material. Additionally, the second material is less compliant than the first material such that the reinforcing segment 852 reinforces the body 852 through its structural and material properties.

[0622] The reinforcing segments 855 are spaced at a set distance from the rim 853. In alternative embodiments, the reinforcing segments 855 may be spaced at a set distance from the base 851. Alternatively, the reinforcing segments 855 may be spaced around the body 852 at varying distances from the rim 853. The reinforcing segments 855 may be combined with other flow director bodies described or claimed herein, including flow directors having a body including a lower body portion and an upper body portion. In those embodiments, the reinforcing segments may extend entirely or partially around the lower body portion. Alternatively, the reinforcing segments may extend entirely or partially around the upper body portion. In a further alternative, the reinforcing segments may extend from the lower body portion and at least partially around the upper body portion.

[0623] 58-60 show a further embodiment of a flow director 860 that can replace the flow director 4246 of the cushion module 4020. In this embodiment, the flow director 860 has a base 861 and a body 862 that extends upwardly from the base 861 and terminates at a rim 863. The base 861 of each flow director is a region of increased thickness compared to the wall thickness of the partition wall 4242. In this embodiment, the base 861 takes the form of an island that extends from the partition wall 4242 into the second chamber 240. In other words, the base 861 in this embodiment takes the form of a localized region of increased wall thickness compared to the wall thickness of the partition wall 4242. This embodiment differs in that the bases 861 of the flow directors 860 are joined together to form a common block 865 from which a separate body 862 extends. The common block 865 has a footprint that extends laterally beyond the corresponding side edges of the nostril openings 234. Apart from the gas flow channels 812 that extend through the common block 865, the common block 865 is a solid structure. The common block 865 behaves as a monolithic structure, such that deformation forces applied to the wall portion 276 are transferred through the common block 865 to the deflection panel 294. By transferring the deformation forces to the deflection panel 294, the gas channels 812 in the common block 865 are protected from buckling or collapsing when a deformation force is applied to the wall portion 276. An advantage of the common block 865 is that the deformation force is spread across a larger area laterally of the deflection panel. This distributes the deformation force more evenly across the width of the deflection panel 294, thus providing a more controlled deformation of the deflection panel 294. A further advantage is that a deformation force applied to one body 862 is transferred, at least in part, through the common block 865 to the other body 862 (or multiple other bodies 862 depending on the number of bodies 862 incorporated in the cushion module 4020). The force transfer increases the overall resistance of the flow director 860 to buckling.

[0624] 60, the common block 865 is angled upward from the partition wall 4242 on the proximal and distal sides of the common block 865, and on the outer side of the common block 865. The angled sides of the common block 865 may take the form of a fillet, or in other embodiments may be chamfered. The top surface of the common block 865 is angled relative to the partition wall 4242. The relative angle is downward in the proximal direction, i.e., the proximal side of the top surface spaced from the partition wall 4242 by a distance less than the distance of the top surface from the partition wall 4242 on the distal side of the common block 865.

[0625] 61-63 show a modification of the flow guide 860 as a further embodiment of the flow guide 870 that can be used in place of the flow guide 4246 in the cushion module 4020. The flow guide 870 has the same form of base 871, body 872 and rim 873 as the flow guide 860. That is, the base 871 is in the form of a common block 875. However, the flow guide 870 differs from the flow guide 860 in that the peripheral wall of the common block 875 is more steeply inclined. As a result, the distal side of the common block 875 forms the proximal edge of the deformation panel 294. This means that the deformation force transmitted through the common block 875 is transmitted directly to the deformation panel 294 instead of being transmitted through the tapered distal wall of the distal portion 810 or the common block 865.

[0626] The bodies 862 and 872 have a constant wall thickness from their respective bases 861, 871 to their rims 863, 873. In an alternative embodiment, the bodies 862, 872 may include a transition delineating the upper and lower body portions. The transition may take the form of a step, such as step 844 of the flow director 840. The step may form a transition between the lower body portion having a greater wall thickness than the wall thickness of the upper body portion. For example, the bodies 862, 872 may be replaced with any one of the bodies 822, 832, 842 that includes different wall thicknesses for the upper and lower body portions. The body may also be replaced with the body 852 that includes a reinforcing segment.

[0627] In further variations, the bases 861 and 871 may be combined with any of the bodies 248, 1248, 2248, and 3248.

[0628] Other features may be combined with bodies 862 and 872. Such features may include, for example, reinforcing segments 855 from flow director 850 described above.

[0629] 64 and 65A-65B show an alternative flow director 880 that may form part of the cushion module 4020. The flow director 880 has the same general configuration as the flow director 4246 in that it includes a base 881, a body 882 extending from the base 881, and a rim 883. The base 881 joins the body 882 to the partition wall 4242. The base 881 forms a smooth transition between the body 882 and the partition wall 4242. As with the flow director 4246, a portion of the outer wall 288 extends laterally outwardly of a second opening 884 defined by the rim 883. As described above with respect to the cushion module 4020, when the patient interface 10 is attached, the nostril openings 234 expand laterally, thereby causing the nostril openings 234 to expand laterally outwardly so that the outer wall 288 does not extend over the second opening 884 when in use.

[0630] The body 882 includes a transition section 885 that delineates the upper body section 887 from the lower body section 886. The lower body section 886 has a wall thickness that decreases from the base 881 to the transition section 885. The upper body section 887 has the same wall thickness from the transition section 885 to the rim 883. The lower body section 886 is angled proximally such that the proximal side of the lower body section 886 that extends from the base 881 to the transition section 885 is shorter than the distal side of the lower wall section 886 that extends from the base 881 to the transition section 885. The upper body section 887 is angled proximally and laterally inward. The transition section 885 occupies a sloped plane similar to the lower body section 886. However, the slope of the lower body section 886 and the transition section 885 is less than the slope present in the flow director 4246. The angling of the lower and upper body portions 886, 887 and the lateral positioning of the flow director 880 facilitate directing breathing gases from the flow director 880 to the nostrils through one or more nostril openings 234. The flow director 880 also differs from the flow director 4246 in that the transition portion 885 is closer to the divider wall than the transition portion 802 for the flow director 4246.

[0631] Flow director 880 further differs from flow director 4246 in that a base of the, or each, flow director 880 joins outer wall 288 at wall portion 276. In this arrangement, proximal portion 808 is located between flow directors 880 and between spacer ribs 888 and wall portion 276. In other embodiments, flow director 888 is spaced apart from wall portion 276 such that proximal portion 808 is positioned between outer portion 800.

[0632] The base 821 of each flow director is spaced from a vertical mid-plane through the cushion module 4020 (as seen in FIG. 64). A spacer rib 888 spans the gap between the flow directors 880. The spacer rib 888 extends from the base 881 to a position below the transition 885 of each flow director 880. The tops of the spacer ribs 888 form straight lines between the flow directors 880. The spacer ribs 828 overlap the lower reinforcement section 4264 of the partition wall 4242. The spacer rib 888 is aligned in the proximal-distal direction with a distal portion of the rim 883 that defines the second opening.

[0633] The proximal portion 808 of the partition wall 4242 between the spacer rib 888 and the wall portion 276 of the seal member 4230 and the outer portion 800 of the partition wall 4242 has a wall thickness that is greater than the wall thickness of the outer portion 800 of the partition wall 4242. In this embodiment, the wall thickness of the proximal portion 808 is at least 1.5 times the wall thickness of the outer portion 800. The wall thickness of the proximal portion 808 may be up to three times the wall thickness of the outer portion 800. In other embodiments, the wall thickness of the proximal portion 808 may be up to eight times the wall thickness of the outer portion 800.

[0634] The wall thickness of the proximal portion 800 may be different at different locations. In other words, the wall thickness of the proximal portion 808 may vary across the proximal portion 808 in the proximal-distal direction, or laterally, or in both directions.

[0635] In the embodiment shown in Figure 65B, the wall thickness of the proximal portion 808 is greater than the wall thickness of the distal portion 810 of the partition wall 4242 between the spacer rib 888 and the deformation panel 294, and between the outer portion 800 of the partition wall 4242. Figure 65A shows in outline the portion of the distal portion 810 that overlaps with the reinforced section 4264. Thus, in Figure 65A, the wall thickness of the distal portion is represented exclusive of the wall thickness of the reinforced section 4264.

[0636] The partition wall 4242, in this and other embodiments, has a curved profile in the proximal-distal direction. The curved profile extends across substantially the entire lateral dimension of the main portion 244 of the partition wall 4242. Optionally, the curved profile extends through the proximal and distal portions of the partition wall.

[0637] The main portion 244 of the divider wall 4242 is convex in the proximal-distal direction and relative to the nostril opening 234. This convex curvature can be seen in the curved alignment of the proximal portion 808 relative to the distal portion 810 in Figures 35, 50, 52, 53, 54 and 65B. The convex curvature is highlighted by the dashed line CX in Figure 65B.

[0638] In an alternative embodiment shown in Figure 66, the curved contour is concave in the proximal-distal direction and relative to the nostril opening 234. The concave curvature is highlighted by dashed line CV in Figure 66. In one embodiment, as shown in Figure 66, the proximal portion 808 and the distal portion 810 have contours that are angled relative to one another in the proximal-distal direction such that the angle between them at the side of the partition wall in the second chamber is less than 180°.

[0639] In an alternative embodiment, the contour of the proximal portion 808 is curved. The contour of the proximal portion 808 is concave relative to the nostril opening 234. However, it will be appreciated that in the case of a convex curvature, the proximal portion 808 will be concave relative to the first chamber 238. Optionally, the contour of the distal portion 810 is curved. In the case of a concave curvature of the divider wall 4242, the contour of the distal portion 810 may be concave relative to the nostril opening 234. However, in the case of a convex curvature, the distal portion 810 will be concave relative to the first chamber 238.

[0640] 67-69 show a variation of the embodiment shown in FIG. 66. This variation includes the distal portion 810 having a wall thickness that is greater than the wall thickness of the outer portion 800 of the partition wall 4242. The wall thickness of the distal portion is at least 1.5 times the wall thickness of the outer portion. The wall thickness of the distal portion 810 may be up to 3 times the wall thickness of the outer portion 800. In other embodiments, the wall thickness of the distal portion 810 may be up to 8 times the wall thickness of the outer portion 800.

[0641] The wall thickness of the distal portion 810 may vary in the proximal-distal direction. Additionally, the wall thickness of the distal portion 810 may vary laterally. In this embodiment, the distal portion 810 includes one or more tapered regions 900 in which the wall thickness of the distal portion 810 decreases in the direction of an adjacent outer portion 800 or in the direction of an adjacent deforming panel 294 to the same thickness as the respective adjacent outer portion 800 or adjacent deforming panel 294.

[0642] One or more of the tapered regions 900 can be located on the side of the partition wall that faces the first chamber 238. This is shown in FIG. 68 as a tapered region 900 on the distal and outer side of the distal portion 810 adjacent where the distal portion 810 joins the deformation panel 294 and the outer portion 800. In this embodiment, the surface of the partition wall 4242 across where the distal portion 810 abuts the outer portion 800 includes a continuous curvature that is related to the overall curvature of the partition wall 4242. In other words, the side of the distal portion 810 exposed to the second chamber 240 does not include an adjustment to account for the tapered region 900.

[0643] However, in other embodiments, one or more of the tapered regions 900 are located on the side of the partition wall 4242 that faces the second chamber 240. In another embodiment, the tapered regions may be located on both sides of the partition wall 4242.

[0644] The spacer rib 888 includes a tapered region 900 disposed between the proximal portion 808 and the distal portion 810 .

[0645] Additionally, the base 881 of the or each flow guide 880 includes a tapered region 900 where the wall thickness of the distal portion 810 reduces to a thickness that matches the wall thickness of the lower body portion 886 of the one or more flow guides 880.

[0646] The wall thickness of the distal portion 810 may be the same as the wall thickness of the proximal portion 808. However, in another embodiment, the wall thickness of the distal portion 810 is greater than the wall thickness of the proximal portion 808.

[0647] In this and other embodiments, distal portion 810 has a lateral width that tapers inwardly in the distal direction, however, in alternative embodiments, the lateral inward taper of distal portion 810 may be absent.

[0648] 64 , the patient interface 10 includes a tether 902 configured to resist a change in orientation between the lower body portion 886 of each flow director 880 and the divider wall 4242. The tether 902 connects the lower body portion 886 to the distal portion 810 at a location on the lower body portion 886 and on the distal portion 810 that is spaced from the base 821 of each flow director 880. In this particular embodiment, the tether 902 joins the flow director 800 along the lower body portion 886 and the base 881, and joins the distal portion 810 from the base 810 to a location spaced from the base 881.

[0649] The tether 902 can be in a variety of different forms. In this embodiment, the tether 902 is a rib that extends between the lower body portion 886 and the distal portion 810 of each flow director 800.

[0650] Tether 902 is positioned distal to flow director 800. Tether 902 is oriented in a proximal-distal direction.

[0651] Tether 902 may be oriented in other directions in alternative embodiments. In further alternative embodiments, tether 902 may be an extension of lower body portion 886 in the distal direction, the extension having a wall thickness in the proximal-distal direction that is greater than the wall thickness of the remainder of lower body portion 886. The extension may taper inwardly in the distal direction in a cross section parallel to the plane of the distal portion.

[0652] Figures 72-74 show a further variation of the embodiment shown in Figure 66. In this embodiment, the patient interface 10 includes one or more tethers 904 configured to resist movement of the distal portion 810 towards the nostril sealing portion 236 of the outer wall 288.

[0653] 72, the first resilient region 268 includes a support wall 906 and an overhanging lip 908 that projects proximally from the support wall 906. A first wall 270 of the deformation panel 296 extends away from the nose seal portion and extends proximally from the overhanging lip 908 to define a gap 910 between the deformation panel and the support wall 906. When a deformation force is applied to the wall portion 276, the main portion 244 of the divider wall 4242 moves distally as the deformation panel deforms. In doing so, a distal edge of the main portion 244 moves into the gap 910. By allowing such movement, the patient interface is able to absorb the deformation force and substantially avoid buckling of the flow director 870 and the main portion 244. The tether 904 contributes to maintaining the shape of the main portion when subjected to a deforming force, for example a deforming force applied to the wall portion 276 or resulting from a gas pressure difference between the first chamber 238 and the second chamber 240, or from a gas pressure difference between the ambient gas pressure outside the patient interface 10 and the gas pressure within the patient interface 10, as shown in Figures 72 to 74.

[0654] The tethers 904 are configured to collapse when subjected to a compressive force in a proximal-distal direction, for example due to a deforming force applied to the wall portion 276. Such collapse allows movement of the main portion 244 into the gap 910. However, the tethers 904 are also configured to inhibit movement of the main portion 244 toward the nostril sealing portion 236. In other words, any tendency of the main portion 244 to buckle by moving toward the nostril sealing portion 236 is prevented by the tethers 904 anchoring the main portion to the support wall 906. Due to such anchoring, the tethers 904 are under tension resisting displacement of the main portion 244 toward the nostril sealing portion 236.

[0655] In this embodiment, the tether 904 is configured to limit movement of the partition wall away from the first elastic region 268. The tether 904 is a panel that connects the deformation panel 294, the main portion 244, and the first elastic region 268. In this embodiment, the tether 904 connects the distal portion 810 and the first elastic region 268. In connection with connecting to the first elastic region 268, the tether 904 connects the deformation panel 294, the overhanging lip 908, and the support wall 906. As shown in particular in FIGS. 73 and 74, the tether 904 connects the first elastic region 268 and the reinforcement section 4264 associated with the distal portion 810. However, in other embodiments, the tether 904 may connect the deformation panel 294, the main portion 244, and the support wall 906. That is, the tether 904 may not connect to the overhanging lip 908. In other embodiments, the tether may connect only the partition wall 4242 and the first support wall 906 .

[0656] The tethers 904 are configured to collapse under compressive forces in the proximal-distal direction and are configured to resist stretching under tensile forces in the proximal-distal direction and toward the nostril sealing portion 236. In this embodiment, the tethers 904 are panels.

[0657] The tether 904 has a wall thickness that is the same as the wall thickness of the first wall 270 of the modified panel 294. Optionally, the tether 904 has a wall thickness that is less than the wall thickness of the first wall 270 of the modified panel 294.

[0658] The tethers 904 are perpendicular to the first wall 270 of the modified panel 294, as shown in Figure 74. In this embodiment, the tethers 904 are disposed in a vertical mid-plane through the patient interface 10, taking into account the upright orientation of the patient interface 10. However, other embodiments may include tethers 904 that are oriented at an angle relative to the proximal-distal direction.

[0659] The tether 904 includes a free edge 912 exposed to the first chamber 238. The free edge 912 is a straight line extending between the first elastic region 268 and the deformation panel 294 or the distal portion 810 or the reinforcement section 4264 associated with the distal portion 810.

[0660] The tether 904 includes a point of weakness that induces a collapse of the tether 904 at that point as the distal portion 810 moves toward the first elastic region 268. Optionally, the point of weakness is a localized reduction in the wall thickness of the tether 904. However, in this embodiment, the point of weakness in the free edge 912 is a notch 914 located between the deformation panel 294 and the first elastic region 268. The notch 914 has a V-shape. Other shapes may be selected for the notch 914, provided that the notch 914 functions as a point of weakness.

[0661] In the embodiment shown in Figures 72-74, the patient interface includes one tether 904. However, it will be appreciated that other embodiments may include one or more tethers. Figures 75-77 show one embodiment including two or more tethers 904.

[0662] In that embodiment, the patient interface 10 includes two tethers, each tether aligned proximally-distally with a distal portion. However, the tethers 904 may be spaced further laterally apart. For example, the patient interface may include two tethers 904, each tether 904 aligned proximally-distally with a respective outer portion.

[0663] 75-77, the two tethers 904 are parallel to each other in the proximal-distal direction. However, the two tethers 904 may move away from each other in the distal direction. Alternatively, the two tethers 904 may move toward each other in the distal direction.

[0664] A free edge 914 of each tether 904 extends to a respective flow director 880. Alternatively, the free edge 914 of each tether 904 is integral with a respective flow director 880. The free edge 914 of each tether 904 is integral with a base 881 of a respective flow director 880. However, one tether 904 of the plurality of tethers 904 may extend to or be integral with one of the respective flow directors 880.

[0665] The partition wall 4242 includes a reinforcing structure 916 extending across the distal portion 810 and the outer portion 800 of the partition wall 4242 and adjacent the deformation panel 294. The reinforcing structure 816 is configured to resist deformation of the distal portion 810 and the outer portion 800. In this embodiment, the reinforcing structure 916 is a lateral reinforcing rib extending across the distal portion 810 and the outer portion 800 at a location distal to the or each flow director 880. The additional wall thickness associated with the reinforcing structure 916 provides resilience to deformation of the partition wall 4242 along the line of the reinforcing structure 916. This contributes to preferential deformation of the partition wall 4242 at the deformation panel 294 and therefore to maintaining the shape of the partition wall 4242 when the partition wall 4242 is subjected to a deformation force applied through the wall portion 276.

[0666] The reinforcing structure 916 is positioned such that there is a spacing between the reinforcing structure 916 and the deforming panel 294, optionally the spacing being constant along the reinforcing structure 916. In this embodiment, the spacing varies along the reinforcing structure. The spacing between the reinforcing structure 916 and the deforming panel 294 is greater across the distal portion 810 than the spacing between the reinforcing structure 916 and the deforming panel 294 across the outer portion 800. The spacing between the reinforcing structure and the deforming panel decreases laterally. The reduction in spacing may be continuous, stepped, or discontinuous. Additionally, the spacing may vary differently in other embodiments. In this embodiment, the spacing between the reinforcing structure 916 and the deforming panel 294 is greatest at a central location.

[0667] 78 and 79, the reinforcing structures 916 are lateral reinforcing ribs and are on the side of the divider wall 4242 exposed to the second chamber 240. In other embodiments, the reinforcing structures 916 may be lateral reinforcing ribs and may be on the side of the divider wall 4242 exposed to the first chamber 238.

[0668] In other embodiments, the reinforcement structure 916 includes a first lateral reinforcement rib on a side of the partition wall 4242 exposed to the second chamber 240 and a second lateral reinforcement rib on a side of the partition wall 4242 exposed to the first chamber 238. The first and second lateral reinforcement ribs may be aligned on opposite sides of the partition wall 4242 in the proximal-distal direction. Alternatively, the first and second reinforcement ribs are offset on each side of the partition wall in the proximal-distal direction. Alternatively, the first and second reinforcement ribs may be aligned in the proximal-distal direction on each side of the partition wall 4242 in one or more locations and may be offset in the proximal-distal direction on each side of the partition wall 4242 in other locations.

[0669] Other embodiments may be variations on the configurations for the first and second reinforcing ribs described above. For example, the spacing for the first reinforcing rib from the deformed panel 294 is different than the spacing for the second reinforcing rib from the deformed panel 294. In another example, the spacing for the first reinforcing rib from the deformed panel 294 is constant and the spacing for the second reinforcing rib from the deformed panel 294 varies. In another example, the spacing for the second reinforcing rib from the deformed panel 294 is constant and the spacing for the first reinforcing rib from the deformed panel 294 varies.

[0670] 78 and 79, the reinforcement structure 916 has a consistent profile along the length of the reinforcement structure 916. In other embodiments, the reinforcement structure 916 has a profile that varies along the length of the reinforcement structure 916. Alternatively, the reinforcement structure 916 may have a profile that tapers in height laterally above the partition wall 4242. The reinforcement structure may have a polygonal profile, a rectangular profile, a trapezoidal profile, a semicircular profile, or a circle segment profile.

[0671] The reinforcement structure 916, in this embodiment, is spaced apart from each respective flow director 880. However, the reinforcement structure 916 may be coupled to the or each respective flow director 880.

[0672] The patient interface 10 includes one or more deformation zone tethers 918 (FIGS. 80-82) configured to inhibit inversion of the partition wall 4242. The, or each respective deformation zone tether 918 extends between a side of the partition wall 4242 exposed to the first chamber 238 and the outer wall 288 of the seal member 4230. As shown in particular in FIGS. 81 and 82, the seal member includes two deformation zone tethers 918. Each deformation zone tether 918 extends from the outer wall to the distal portion 810. Although the following description is in the context of the seal member having two deformation zone tethers 918, it will be understood that the seal member 4230 may have only one deformation zone tether 918. As such, it will be understood that the following description of different configurations of the deformation zone tethers 918 equally applies to embodiments of the patient interface 10 including only one deformation zone tether 918.

[0673] The deformation area tethers 918 connect with the partition walls 4242 between the deformation panel 294 and the flow guide 880 or each of the flow guides 880. In the embodiment shown in Figs. 80-82, the deformation area tethers 918 are spaced apart from the deformation panel 294. The deformation area tethers 918 are spaced apart from the flow guide 880. Optionally, each respective deformation area tether 918 may be integral with each of the flow guides. For example, each respective deformation area tether 918 may be integral with the base 881 of the respective flow guide 880.

[0674] 81 and 82, each respective deformation zone tether 918 extends from the partition wall 4242 and the outer wall 288 and has a free edge 920 within the first chamber 238. The free edge 920 is straight. In this embodiment, the deformation zone tether 918 has a flat, planar structure.

[0675] The patient interface 10 includes two deformation region tethers, where the angle between the proximal faces 922 of each respective proximal deformation region tether 918 is greater than 140°. Alternatively, the angle between the proximal faces 922 of each respective proximal deformation region tether 918 is greater than 160°.

[0676] 81 and 82, the two deformation zone tethers 918 extend to the same location on the distal portion 810. The two deformation zone tethers 918 extend to the reinforced section 4264. However, in an alternative embodiment, the two deformation zone tethers 918 extend toward each other to spaced apart locations on the distal portion 810. In another embodiment, the deformation zone tethers 918 may extend to spaced apart locations on the distal portion, but the deformation zone tethers 918 may not extend toward each other.

[0677] The deformation zone tether 918 includes a first portion 924 that connects to the outer wall and a second portion 926 that extends to the main portion 244. In an alternative embodiment, one connection point is to the main portion 244 and the other connection point is to the outer wall 288 at a level below the distal portion 810, considering the upright orientation of the patient interface. In such an embodiment, the deformation zone tether 918 may be a cord or wire or cable. In a further alternative embodiment, the first portion 924 has a flat planar structure and the second portion 926 is curved such that the angle on the proximal side between the tangents at each location along which the second portion 926 extends is between 140° and 180°.

[0678] The deformation zone tether 918 is positioned to permit movement of the main portion 244 of the partition wall 4242 when a deformation force is applied to the wall portion 276, while being positioned to resist deformation or inversion of the main portion toward the nostril sealing portion 236. Thus, the location of the deformation zone tether 918 within the first chamber 238 allows the deformation zone tether 918 to act as a tensile resistor to deflection or inversion of the main portion 244 toward the nostril sealing portion 236. The wide angle between the proximal faces 922 reduces the extent to which the deformation zone tether 918 exerts a tensile or compressive influence on the movement of the main portion 244. The deformation zone tether 918 can be configured to exert a substantially constant tensile force on the partition wall 4242 throughout its range of movement under the influence of a deformation force applied to the wall portion 276. This is facilitated by orienting the flat panel deformation area tethers 918 substantially perpendicular to the direction of movement of the main portion 244 .

[0679] The tensile resistance provided by the deformation zone tether 918 results from the connection to the outer wall being lower than the connection to the main portion 244. In the embodiment shown in Figures 80-82, the deformation zone tether 918 extends to a height below the lowest point of the partition wall 4242 when the patient interface is in an upright orientation. The deformation zone tether 918 extends to a height below the highest point of the oral opening when the patient interface is in an upright orientation. Additionally, the deformation zone tether 918 extends from the distal portion 810 to the outer wall 288 at a location distal to the proximal-most portion of one or more nostril openings 234.

[0680] The free edge 920 extends from the outer wall 288 at a location proximal to the reinforced section 4264. Alternatively, the free edge 920 extends from the outer wall 288 at a location distal to the one or more oral openings 232. Alternatively, the free edge 920 extends from the outer wall 920 at a location distal to the spacer rib 888.

[0681] In alternative embodiments, the free edge 920 may be curved. The curvature may be a convex curvature or a concave curvature.

[0682] The embodiment shown in Figures 80-82 includes deformation zone tethers 918 having the same wall thickness throughout. An alternative embodiment shown in Figure 83 includes the same flat panel deformation zone tethers 918 formed as described above, but differs with respect to wall thickness. Specifically, the deformation zone tethers 918 in Figure 83 are panels having a wall thickness that decreases from the partition wall to the free edge.

[0683] 85-87 illustrate an alternative flow guider 880 configuration for the cushion module 4020. In this embodiment, the flow guider 880 is the same as the flow guider 880 described above in connection with FIGS. 64 and 65A. In that embodiment, the flow guiders 880 are the same size and therefore provide the same gas flow rate. The flow guiders 880 in FIGS. 85-87 differ in that they are configured to provide a greater gas flow rate through one flow guider 880 than through another flow guider 880. In other words, one of the respective flow guiders 880 is configured to have a first resistance to gas flow and another of the respective flow guiders 880 is configured to have a second resistance to gas flow, the first resistance to gas flow being less than the second resistance to gas flow.

[0684] 86 and 87, it can be seen that the first opening 889A and the second opening 884A of one of the respective flow directors 880A are larger than the first opening 889B and the second opening 884B of the other of the respective flow directors 880B. In an alternative embodiment, the first opening 889A or the second opening 884A of the flow director 880A are larger than the first opening 889B or the second opening 884B of the respective flow director 880B.

[0685] Expressed another way, the asymmetry in the flow rates between the flow guider 880A and the flow guider 880B is the result of different opening sizes of the flow guider 880A and 880B. For example, the ratio of the area of ​​the first opening 889A of the flow guider 880A to the area of ​​the first opening 889B of the other flow guider 880B is in the range of 1:1 to 1:0.1. Alternatively, the ratio of the area of ​​the second opening 884A of the flow guider 880A to the area of ​​the second opening 884B of the other flow guider 880B is in the range of 1:1 to 1:0.1. As a further alternative, the ratio of the combined area of ​​the first opening 889A and the second opening 884A of the flow guider 880A to the combined area of ​​the first opening 889B and the second opening 884B of the other flow guider 880B is in the range of 1:1 to 1:0.1. Alternatively, the ratio of the area of ​​the second opening of one of the respective flow directors to the area of ​​the second opening of another of the respective flow directors is in the range of 1:0.5 to 1:0.2. Alternatively, the ratio of the area of ​​the second opening of one of the respective flow directors to the area of ​​the second opening of another of the respective flow directors is 1:0.33. In a further alternative, the two flow directors 880A and 880B have the same shape and the ratio of the dimension of the flow director 880A to the dimension of the flow director 880B is in the range of 1:0.5 to 1:0.2. The ratio of the dimension of the flow director 880A to the dimension of the flow director 880B may be 1:0.33.

[0686] Despite the difference in size between flow director 880A and flow director 880B, the orientation and position of flow directors 880A and 880B and spacer ribs 888 remain the same as the flow director 880 of the embodiment shown in FIG.

[0687] The flow director 880A, with the larger area of ​​the first opening 889A and the second opening 884B, has a lower resistance to gas flow and therefore a higher flow rate of gas flow than the flow through the flow director 880B. The higher flow rate of gas flow through the flow director 880A directs more gas flow to one nostril of the patient than the other nostril. In other words, an asymmetric flushing flow is provided to both nostrils. It is expected that the higher flow rate of gas to one nostril will promote unidirectional flushing of the dead space in the nasal cavity with the stream of breathing gas flowing into one nostril and out of the other nostril. While flushing flow is provided to both nostrils from each of the flow directors 880A and 880B, less flow will enter the nostril associated with the flow director 880B, resulting in an asymmetric flushing flow through the nostrils and nasal cavity. It is believed that the outflow through the other nostril is promoted by the relatively lower gas flow rate through the flow director 880B associated with that nostril. That is, the lower gas flow rate directed to the other nostril provides less resistance to gas flow out of the same nostril. It is believed that unidirectional flushing of dead space within the nasal cavity can improve flushing of the anatomical dead space when the patient's mouth is closed. It is also believed that unidirectional flushing is still at least somewhat effective when the patient's mouth is open.

[0688] An alternative to having two flow directors 880A and 880B of different sizes includes a patient interface including only one flow director 880, as shown in Figures 88-90.

[0689] In this embodiment, the one flow director 880 is configured to deliver a flushing flow of breathing gas to one nostril. That is, the flow director 880 is configured to direct the flow of gas through the nostril opening to one of the patient's nostrils. The one flow director 880 is configured to deliver the flushing flow to one nostril to allow flushing of the dead space in the nasal cavity. It is expected that delivering a flushing flow of gas through the one flow director 880 to one nostril will likely cause unidirectional flushing of the dead space in the nasal cavity, with the flushing flow flowing through the nasal cavity and out through the other nostril into the second chamber 240.

[0690] 88-90 has the form of flow guider 880 described above in relation to Figures 64, 65A and 65B, but the flow guider may have the form of any one of the flow guiders disclosed above. That is, the flow guider may have the form of any one of flow guiders 246, 1246, 2246, 3246, 4246, 820, 830, 840, 850, 860 or 870.

[0691] 88-90, the second opening 884 of the flow director 880 is laterally offset from a mid-plane between the lateral sides of the patient interface 10. Also, the second opening 884 of the flow director 880 is laterally spaced from the mid-plane. Similarly, the first opening 889 of the flow director 880 is laterally offset from a mid-plane through the patient interface 10. Also, the first opening 889 of the flow director 880 is laterally spaced from the mid-plane through the patient interface 10.

[0692] The partition wall 4242 includes a first side portion 928 adjacent to the mid-plane opposite the flow guide 880. The first side portion 928 corresponds to where the second flow guide of the pair of flow guides 880 was. The first side portion 928 has a first wall thickness. The partition wall 4242 further includes one of the outer portions 800 extending laterally outward from the first side portion 928. The outer portion 800 has a second wall thickness, the first wall thickness of the first side portion 928 being the same as the second wall thickness. In an alternative embodiment, the first wall thickness of the first side portion 928 is greater than the second wall thickness.

[0693] According to the alternative embodiment, the transition 930 between the first lateral portion 928 and the outer portion 800 is spaced laterally from the mid-plane by substantially the same distance as the most outboard positioned portion of the flow director 880 is spaced from the mid-plane. Alternatively, the transition 930 between the first lateral portion 928 and the outer portion 800 is spaced laterally from the mid-plane by a distance greater than the most outboard positioned portion of the flow director 880 is spaced from the mid-plane. In a further alternative embodiment, the transition 930 between the first lateral portion 928 and the outer portion 800 is spaced laterally from the mid-plane by a distance less than the most outboard positioned portion of the flow director 880 is spaced from the mid-plane.

[0694] 91-93 show a variation of the embodiment shown in FIGS. 88-90. In FIGS. 91-93, the patient interface 10 includes a nostril opening 234 that seals around the patient's nares and includes a channel 930 extending from a first chamber 238 to the nostril opening 234, the channel configured to align with one of the patient's nares. The remaining portion of the nostril opening 234 is configured to align with the other of the patient's nares. This embodiment is expected to operate similarly to the embodiment described above with only one flow director (FIGS. 88-90). That is, the channel 934 and nostril opening 234 are configured to deliver a flushing flow of gas to the first nostril when the interface is attached to the patient, which flushing flow causes the nasal cavity to flush and the gas flushed through the nasal cavity flows through the other nostril, through the remaining portion of the nostril opening 234, and into the second chamber 240. As such, this embodiment is expected to provide one-way flushing of the nasal cavity.

[0695] In this embodiment, channel 930 is configured to allow gas from the other of the patient's nostrils to flow into second chamber 240. Additionally, channel 930 is configured to allow gas from channel 930 to flow into second chamber 240.

[0696] The channel 930 can be configured to deliver a gas flow to only one of the patient's nostrils. However, in this embodiment, the channel 930 is configured to deliver a gas flow to both of the patient's nostrils. The gas flow to the patient's nostrils includes a first and a second gas flow from the channel 930, the first and second gas flows being unequal. The first gas flow is at a higher flow rate than the second gas flow. The first gas flow to the first nostril is a flushing gas flow. The flushing gas flow delivered to one nostril while both nostrils are open allows for unidirectional flushing of the nasal cavity and the anatomical dead space of the upper throat, as described above. If the nostril to which the flushing gas flow is delivered becomes occluded, the second gas flow provides breathing gas to the patient to continue the breathing cycle.

[0697] The division of the gas flow from the channel 930 is possible due to the configuration of the channel 930. The channel 930 is defined in part by a peripheral wall 932 extending between the divider wall 4242 and the nostril opening 234, and in part by a divider wall 934 extending between the divider wall and a recessed position from the nostril opening 234 to form the channel 930 with the peripheral wall 932. The divider wall terminates at the outlet end of the channel at a divider edge 936. The divider edge 936 has a curved shape recessed from the nostril opening 234 while connecting the rim 386 of the nostril opening 234 proximal and distal to the rim 286. The recessed position of the divider wall 934 from the nostril opening 234 allows gas from the channel 234 to flow into the second chamber 240 when the patient interface 10 is attached to the patient. The divider wall 934 is recessed from the nostril opening to avoid contact with the patient. That is, the partition wall 934 is recessed sufficiently from the nostril openings 234 so that when the patient interface 10 is attached to the patient, there is a gap for gas flow between the end of the partition wall 934 and the patient's nasal septum.

[0698] The channel 934 tapers from the divider wall 4242 to the nostril opening 234 to accelerate the gas through the channel 934. In other embodiments, the profile of the channel 934 is constant from the divider wall 4242 to the nostril opening 234.

[0699] 83 and 84 show another alternative flow director 890. The flow director 890 has the same general form as the flow director 880 in that it includes a base 891, a body 892 extending from the base 891, and a rim 893. The base 891 joins the body 892 to the divider wall 4242. The base 891 forms a smooth transition between the body 892 and the divider wall 4242. As with the flow director 880, a portion of the outer wall 288 extends laterally outwardly of the second opening 894 defined by the rim 893. As explained above with respect to the cushion module 4020, when the patient interface 10 is attached, the nostril openings 234 expand laterally such that the nostril openings 234 expand laterally outwardly such that the outer wall 288 does not extend over the second opening 894 in use.

[0700] The body 892 includes a transition section 895 that delineates a lower body portion 896 from the rim 893. Unlike the flow director 880, the flow director 890 does not include an upper body portion. The lower body portion 896 has a wall thickness that decreases from the base 891 to the transition section 895. The lower body portion 896 is angled in the proximal direction such that the proximal side of the lower body portion 896 that extends from the base 891 to the transition section 895 is shorter than the distal side of the lower body portion 896 that extends from the base 891 to the transition section 895. The transition section 895 occupies an inclined plane similar to the lower body portion 896. However, the inclination of the lower body portion 896 and the transition section 895 is less than the inclination present in the flow director 4246. The angled lower body portion 896 and laterally positioned flow director 890 facilitate directing breathing gas from flow director 890 into the nostril through nostril opening 234. Flow director 890 also differs from flow director 4246 in that transition portion 895 is closer to divider wall 4242 than transition portion 802 of flow director 4246.

[0701] The lower body portion 896 has a wall thickness and the rim 893 has another wall thickness that is less than the wall thickness of the lower body portion such that the transition portion 895 has a tapered wall thickness.

[0702] In this embodiment, the spacer rib 898 joins the lower body portion 896 and the transition portion 895 at a location spaced from the rim 893. The spacer rib 898 is located distal to an imaginary line connecting the centers of the second openings 894 of each flow director 890. The base 891 or lower body portion 896 of the flow director 890 joins with the wall portion 276.

[0703] The inner wall of the flow director 890 tapers inwardly from the first opening 899 to the second opening 894 to form an inwardly tapered channel 930 between the first opening 899 and the second opening 894. In this embodiment, the wall thickness of the rim 893 is greater than the wall thickness of the outer portion 800, the distal portion 810, or the proximal portion 808 of the divider wall.

[0704] In this embodiment, the patient interface 10 includes one or more deformation region ties 918 extending between the side of the partition wall 4242 exposed to the first chamber 238 and the outer wall 288 of the seal member 4230, and the main portion 244 of the partition wall 4242 has a concave contour in the proximal-distal direction relative to the nostril opening 234, and the or each respective flow guide portion 890 includes a base 891, a lower body portion 896, a rim 893 forming a second opening 894 that opens into the second chamber 240, and a transition portion 895 extending between the lower body portion 896 and the rim 893.

[0705] For all of the above-described embodiments of the flow guide, the area of ​​the second opening is 20 to 160 mm 2 Or 40~140mm 2 Or 40~100mm 2 Or 40~80mm 2 Or 40~60mm 2 Or 30~80mm 2 Or 30~60mm 2 Or 20~60mm 2The only exception to this range is the embodiment shown in Figures 85-87, particularly for the flow director 880B having the smaller size of the two asymmetrically sized flow directors 880A and 880B, where the area of ​​the second opening 884B of the smaller flow director may be smaller than the range stated above.

[0706] For all of the flow director embodiments described above, the gas velocity through the flow director is in the range of 1-40 m / s. It will be understood that for a given gas pressure delivered to the patient interface, the velocity will likely vary, but is expected to fall within the ranges described above. The expected gas velocity is based on the patient interface being attached to the patient without occlusion of the first chamber 238 or the second chamber 240, or the flow directors 246, 1246, 2246, 3246, 4246, 820, 830, 840, 850, 860, 870, 880, or 890.

[0707] As mentioned above, the patient interface 10 further includes a frame 30 and a conduit connector 40 .

[0708] The frame 30 includes a central body portion 302 that includes one or more channels that carry respiratory gas from a gas source to the cushion module 20 and, therefore, to the patient. The frame 30 includes side wings 304 extending from the central body portion 302. Each side wing 74 includes a pair of openings 308 arranged to cooperate with headgear (such as elastic straps) for attaching the patient interface to the patient. The headgear operates by pulling the mask 10 into contact with the patient's face to form a substantially airtight seal when respiratory gas at elevated pressure is delivered to the patient through the mask 10. One opening 308 of each side wing 304 includes a bar 306 that connects with a headgear clip to allow easier connection and disconnection from the headgear.

[0709] Although this embodiment includes a frame 30, in alternative embodiments, the headgear connection points may be integral with or connected to the housing 210. In that case, the frame 30 is not necessary and may be omitted from such embodiments.

[0710] The frame 30 further includes a connector sleeve 310 that includes four arcuate fingers 312. The connector sleeve 312 has an inner wall 314 that includes a concave profile having a shape in the shape of a spherical segment. The outer wall of the connector sleeve 310 is shaped to fit within the sleeve 220 of the housing 210. The arcuate fingers 312 are spaced apart by detents that are shaped to mate with key structures 222. The location of the key structures 222 and detents ensure that the frame is properly aligned with the housing 210 when they are mated.

[0711] Each arcuate finger 312 has an end with an arcuate flange portion 318 that forms a snap fit with the radially inwardly projecting lip 298 of the sleeve 220. The snap fit holds the frame 30 to the housing 210. The snap fit may be releasable or may be a permanent fit between the frame 30 and the housing 210.

[0712] Considering the above discussion of variations of the schematic form shown in FIG. 1, one such variation, applicable to the aspects and embodiments of the schematic form described below, is where the housing 210 and the frame 30 are integrally formed. In other words, the patient interface 10 can include an integral structure that performs the same functions of the housing 210 and the frame 30. Although the housing 210 and the frame 30 are described as being separate components of the patient interface 10, this description should be read to include the option of integrally formed components that function similarly to the housing 210 and the frame 30. Alternatively, the frame 30 may be connected to the housing 210 by any conventional means, such as adhesive or welding. For example, the frame 30 can be permanently connected to the housing 210 by ultrasonically welding the housing 210 and the frame 30 together.

[0713] The conduit connector 40 includes an elbow 60 and a socket insert 50 that couples the elbow 60 to the frame 30. The conduit connector 40 further includes a swivel connector 80 that connects to a conduit that delivers breathing gas from a source such as a ventilator, humidifier, or wall source. The swivel connector 80, elbow 60, and socket insert 50 form a flow path for breathing gas from the conduit to the cushion module 20, 1020, 2020, 3020.

[0714] The socket insert 50 has an outer wall 502 that includes a convex spherical segment. The shape of the spherical segment matches the shape of the concave spherical segment of the inner wall 314 of the frame 30. The outer wall 502 is joined at one end to an inner wall 504. The inner wall 504 includes an inner surface 506 that includes a shoulder 508 that projects radially inward. The socket insert 50 snap-fits into the frame 30 such that the outer wall 502 fits within the concave segment of the inner wall 314 of the frame 30 (FIG. 4). This connection forms a ball-and-socket type connection that allows the socket to rotate within the spherical segment of the inner wall 314 of the frame 30.

[0715] The elbow 60 includes a first conduit section 602 and a second conduit section 608. The longitudinal axes of the first conduit section 602 and the second conduit section 608 are set at an oblique angle. Thus, breathing gas flowing through the elbow 60 undergoes a redirection from the first conduit section 602 to the second conduit section 608. The conduit section 602 includes a radially protruding flange 606. The elbow 60 is connected to the socket insert 50 by snap-fitting the flange 606 into a shoulder 508. However, in other embodiments, the elbow 60 may be connected to the socket insert 50 by welding or by adhesive, in which case the shoulder 508 and the flange may be omitted.

[0716] The second conduit section 608 includes an inlet 610 for breathing gas. The inlet 610 is at a distal end of the second conduit section 608. The second conduit section 608 further includes structure (see FIG. 5) that cooperates with an anti-asphyxiation valve 70 (FIGS. 2, 4 and 5) to allow ambient air to enter the patient interface in the event that the source of breathing gas fails or the conduit carrying gas from the source to the patient interface 10 becomes blocked. More specifically, the second conduit section 608 includes an opening 612. The opening is at a lower portion of the second conduit section 608. A spine 614 is disposed adjacent the opening 612 and supports a panel 616 spaced apart from the opening 612. The spacing of the panel from the opening provides a gap 618 through which ambient air can access the opening.

[0717] The anti-asphyxiation valve 70 includes a valve seat 702 and a valve seal 714. The valve seat 702 includes a sealing surface 704 against which the valve seal 714 seals the valve 70. The valve seat 702 further includes a sleeve 708 having a bead 710 protruding radially outwardly therefrom. The bead 710 is at an end of the sleeve 708. The valve seat 702 further includes a spigot 712 that mates with the valve seal 714.

[0718] The valve seal 714 includes a flap 720 that can transition between an open position in which the elbow 60 is open to the flow of breathing gas from the source and a closed position in which the elbow 60 is closed to the flow of breathing gas from the source. In the open position, ambient air is prevented from accessing the interior of the elbow 60, and in the closed position, ambient air is allowed to access the interior of the elbow 60. In this embodiment, the flap 720 is formed of a flexible material. The flap 720 is joined to the lug 716 by a hinge 722. The hinge 722 includes a section of flexible material having a reduced wall thickness. The lug 716 is configured to aid in positioning the valve seal 714 within the end of the second conduit portion 608. Additionally, the lug 716 includes a recess 718 adapted to receive the spigot 712. The fit of the spigot 712 within the recess 718 properly orients the valve seal 714 on the valve seat 702.

[0719] Pressurized breathing gas, when supplied from the source, flows through the elbow 60 into the cushion module 20, 1020, 2020, 3020. The increased pressure of the breathing gas causes the flap to swing about the hinge 722 and cover the opening 612 in the second conduit portion. This represents the "open position" described above in that the flap 720 prevents ambient air from entering the elbow 60 through the gap 618 and the opening 612. In the event that the source of breathing gas fails or the conduit connecting to the source becomes blocked, the anti-asphyxiation valve 70 will close as the air pressure inside the elbow 60 will equal the air pressure outside the elbow 60, and therefore the flap 720 will transition to the "closed position" described above due to the inherent resiliency in the flexible material forming the hinge 722. In the closed position, the openings 612 are exposed to the inside of the elbow 60 so that the patient's natural breathing cycle draws air into the elbow 60 and cushion module 20, 1020, 2020, 3020 through one or more openings, as shown by the flow arrows in FIG. 5.

[0720] The valve seat 702 includes a radially protruding step configured to mate with the elbow 60. In particular, the step 724 is configured to mate with an end of the second conduit portion 608. The coupling may include a snap-fit ​​connection, or may include a permanent fixation, such as a weld or adhesive fixation.

[0721] The valve seat 702 mates with a swivel connector 80 configured to connect with a conduit from a breathing gas source. The swivel connector 80 includes a radially inwardly projecting shoulder 82 that is cooperable with a stepped portion 724 of the valve seat 714 to connect the valve seat 714 to the swivel connector 80. The connection is a snap-fit ​​connection. However, in other embodiments, the connection may include a permanent fixation, such as welding or adhesive fixation.

[0722] Those skilled in the art of the present invention will appreciate that many variations and modifications can be made to the preferred embodiments without departing from the spirit and scope of the invention.

[0723] In the claims that follow, and in the foregoing description, unless otherwise required by context, express expression or necessary implication, the words "comprises" and variations such as "comprises" or "comprising" are used in their inclusive sense, i.e., to specify the presence of stated features, but not to preclude the presence or addition of further features, in various embodiments of the apparatus and methods as disclosed herein.

[0724] In the above description of the preferred embodiment, certain terms are used for clarity. However, the present invention is not intended to be limited to the certain terms so selected, and each certain term should be understood to include all technical equivalents that operate in a similar manner to achieve a similar technical purpose. Terms such as "front" and "back", "inner" and "outer", "upper", "lower", "upper" and "lower", "lower" and "upper", "vertical" and "horizontal" are used as convenient terms to provide reference points and should not be construed as limiting terms. These terms when used in reference to the patient interface throughout this specification, including the claims, refer to an orientation relative to the normal operating orientation, i.e., when the interface is attached to the patient and the patient's head is upright.

[0725] Throughout this specification and claims, terms such as "joined," "coupled," and "connected" should not be construed as requiring that two separate components be joined together. These terms should be interpreted in context, including the option of referring to the intersection of integrally formed features. For example, the partition wall in the above embodiments joins with the exterior wall, which in those embodiments is integrally formed.

[0726] Moreover, while the present invention has been described in connection with what are presently considered to be the most practical and preferred embodiments, it should be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements falling within the spirit and scope of the invention. Also, the various embodiments described above can be implemented in combination with other embodiments, for example, aspects of one embodiment can be combined with aspects of another embodiment to achieve yet another embodiment. Moreover, each independent feature or component of any given assembly can constitute an additional embodiment.

Claims

1. 1. A non-invasive patient interface configured to form a seal around a patient's mouth and nostrils, comprising: (a) an outer wall defining an interior volume of the patient interface, the outer wall having one or more oral openings in gas communication with the mouth and one or more nasal openings in gas communication with the nares; (b) a divider wall separating the interior volume into a first chamber having the one or more oral openings and a second chamber having the one or more nostril openings; Including, 11. A non-invasive patient interface, wherein the partition wall includes one or more spaced apart flow directors that allow gas to flow from the first chamber to the second chamber, the flow directors configured to direct the flow of gas through the nasal openings.

2. A patient interface as described in claim 1, wherein the or each of the flow guides has a base joined to the partition wall and defining a first opening from the first chamber, a body extending from the base, a rim spaced from the base and defining a second opening opening into the second chamber, and a gas flow channel extending from the first opening in the base to the second opening.

3. A patient interface as described in claim 2, wherein the rim is contoured so that at least a portion of the rim has a substantially consistent spacing from the one or more nostril openings.

4. A patient interface as described in claim 2 or claim 3, wherein the body includes a lower body portion and an upper body portion, the upper body portion including a wall thickness that is less than a wall thickness of the lower body portion.

5. A patient interface described in any one of claims 2 to 4, wherein the main body has a conical contour, a tapered contour, or a stepped contour in a cross section approximately perpendicular to the partition wall in which the flow guide portion is located.

6. A patient interface as described in any one of the preceding claims, comprising two or more flow guide portions, the partition wall including a separation element disposed between the flow guide portions.

7. A patient interface as described in claim 6, wherein the spacing element is joined to each flow guide portion at a position spaced from the rim.

8. A patient interface as described in any one of the preceding claims, wherein the partition wall includes a preferential deformation region that separates one portion of the partition wall from another portion of the partition wall allowing the two portions to move relative to each other.

9. A patient interface as described in claim 8, wherein the preferential deformation region includes a first elastic region and a deformation panel disposed between the first elastic region and the flow guide portion.

10. A patient interface as described in claim 8 or claim 9, further comprising one or more deformation zone ties configured to inhibit inversion of the partition wall, preferably the one or more deformation zone ties extending between a side of the partition wall exposed to the first chamber and the outer wall.

11. A patient interface as described in any one of the preceding claims, wherein the partition wall includes an outer portion arranged laterally outward of the flow guide portion and which, taking into account the upright orientation of the patient interface, is joined to the outer wall along an abutment line that extends at least partially upward and partially downward of the lowest position of the one or more nostril openings, and which does not extend above the highest position of the one or more nostril openings.

12. A patient interface as described in any one of the preceding claims, wherein the patient interface has an inlet into the first chamber for respiratory gas and an exhaust port configured to pass respiratory gas from the second chamber to the outside of the patient interface.

13. A patient interface as described in any one of claims 1 to 12, further comprising a patient engagement surface, and wherein the partition wall includes one or more deformation resistant sections configured to reduce the extent to which the flow guide portion is deformed by a deformation force applied to the patient engagement surface.

14. A patient interface as described in claim 13, wherein the one or more deformation resistant sections comprise portions of the partition wall having a wall thickness greater than a wall thickness of other portions of the partition wall.

15. A patient interface as described in claim 13 or claim 14, wherein the one or more deformation resistance sections are in an area of ​​the partition wall that includes the one or more flow guide portions.

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