SEALING CUSHION

Abstract

A sealing cushion for a respiratory mask assembly, the sealing cushion comprising a patient interface portion having a resiliently deformable sealing membrane for engagement with a patient’s face, and an aperture formed therein for receiving a nasal and/or mouth region of a patient’s face, the sealing membrane comprising a plurality of regions of different thicknesses, the plurality of regions comprising: a compliant nasal region (20) for engagement with the patient’s nasal bridge; a nasal support regions (25) disposed either side of the compliant nasal region for engagement with the sides of the patient’s nose; cheek support regions (30) extending from each of the nasal support regions for engagement at least with the patient’s cheeks, and a compliant base region (35) extending between the cheek support regions, wherein the sealing membrane in the nasal support regions has a greater thickness than in the cheek support regions, and wherein the sealing membrane in the compliant nasal region and the compliant base region has a lower thickness than in the cheek support regions and the nasal support regions.

Claims

1. A sealing cushion for a respiratory mask assembly, the sealing cushion comprising a patient interface portion having a resiliently deformable sealing membrane for engagement with a patient’s face, and an aperture formed therein for receiving a nasal and/or mouth region of a patient’s face, the sealing membrane comprising a plurality of regions of different thicknesses, the plurality of regions comprising: a compliant nasal region for engagement with the patient’s nasal bridge, nasal support regions disposed either side of the compliant nasal region for engagement with the sides of the patient’s nose, cheek support regions extending from each of the nasal support regions for engagement at least with the patient’s cheeks, and a compliant base region extending between the cheek support regions, wherein the sealing membrane in the nasal support regions has a greater thickness than in the cheek support regions, wherein the sealing membrane in the compliant nasal region and the compliant base region has a lower thickness than in the cheek support regions and the nasal support regions, and wherein each cheek support region comprises a reinforced subregion that is separated from the nasal support regions.

2-3. (canceled)

4. The sealing cushion according claim 1, wherein the patient interface portion and/or the aperture therein are substantially triangular in nature.

5. (canceled)

6. The sealing cushion according claim 1, wherein the thickness of each of the plurality of regions is constant across the region and the transitions between the plurality of regions are distinct step-like transitions.

7. The sealing cushion according claim 1, wherein the reinforced subregions are disposed at base corners of the patient interface portion.

8-10. (canceled)

11. The sealing cushion according claim 1, wherein the nasal support regions extend along left and right sides of the patient interface portion between the compliant nasal region and the cheek support regions.

12. (canceled)

13. The sealing cushion according claim 1, wherein the cheek support regions extend along left and right sides of the patient interface portion between the nasal support regions and the base corners of the patient interface portion, and wherein the cheek support regions further extend along a base side of the patient interface portion between the base corners and the compliant base region.

14. (canceled)

15. The sealing cushion according claim 1, wherein the compliant base region extends across the sidewall portion.

16. The sealing cushion according claim 1, wherein the reinforced subregions comprise substantially square-shaped portions.

17. The sealing cushion according claim 1, wherein the reinforced subregions extend from the patient interface portion across the sidewall portion.

18-25. (canceled)

26. A respiratory mask assembly comprising the sealing cushion according to claim 1.

27. A sealing cushion for a respiratory mask assembly, the sealing cushion comprising a patient interface portion having a resiliently deformable sealing membrane for engagement with a patient’s face, and an aperture formed therein for receiving a nasal and/or mouth region of a patient’s face, the sealing membrane comprising a plurality of regions of different thicknesses, the plurality of regions comprising: a compliant nasal region for engagement with the patient’s nasal bridge, nasal support regions disposed either side of the compliant nasal region for engagement with the sides of the patient’s nose, cheek support regions extending from each of the nasal support regions for engagement at least with the patient’s cheeks, and a compliant base region extending between the cheek support regions, wherein the sealing membrane in the nasal support regions has a greater thickness than in the cheek support regions, wherein the sealing membrane in the compliant nasal region and the compliant base region has a lower thickness than in the cheek support regions and the nasal support regions, and wherein the patient interface portion further comprises a compliant inner member extending around substantially all of the perimeter of the aperture in the patient interface portion.

28. The sealing cushion according to claim 27, wherein the compliant inner member has substantially the same width over the majority of its perimeter.

29. The sealing cushion according to claim 27, wherein at least a portion of each nasal support region extends from the compliant inner member of the patient interface portion across a sidewall portion to a mask connection interface.

30. The sealing cushion according to claim 29, wherein the compliant base region extends from the compliant inner member across the sidewall portion to the mask connection interface.

31. The sealing cushion according to claim 27, wherein the sidewall portion comprises reinforced sidewall regions and the cheek support regions extend between the compliant inner member and the reinforced sidewall portions.

32. A sealing cushion for a respiratory mask assembly, the sealing cushion comprising a patient interface portion having a resiliently deformable sealing membrane for engagement with a patient’s face, and an aperture formed therein for receiving a nasal and/or mouth region of a patient’s face, the sealing membrane comprising a plurality of regions of different thicknesses, the plurality of regions comprising: a compliant nasal region for engagement with the patient’s nasal bridge, nasal support regions disposed either side of the compliant nasal region for engagement with the sides of the patient’s nose, cheek support regions extending from each of the nasal support regions for engagement at least with the patient’s cheeks, and a compliant base region extending between the cheek support regions, wherein the sealing membrane in the nasal support regions has a greater thickness than in the cheek support regions, wherein the sealing membrane in the compliant nasal region and the compliant base region has a lower thickness than in the cheek support regions and the nasal support regions, and wherein the sealing cushion comprises a mask connection interface for connection to a respiratory mask body, and a sidewall portion extending between the mask connection interface and the patient interface portion.

33. The sealing cushion according to claim 32, wherein the nasal support regions also extend across at least a portion of the sidewall portion, thereby forming a reinforced subregion of the sidewall portion.

34. The sealing cushion according to claim 32, wherein the sidewall portion comprises reinforced sidewall regions disposed between the cheek support regions and the mask connection interface and/or between the nasal support regions and the cheek support regions.

35. The sealing cushion according to claim 34, wherein the reinforced sidewall portions and the nasal bridge support region have the same thickness.

36. The sealing cushion according to claim 32, wherein the sidewall portion comprises a nasal bridge support region disposed at an apex of the sidewall portion, and wherein the nasal bridge support region extends between the mask connection interface and the compliant nasal region and/or between the nasal support regions.

Description

[0099] Practicable embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, of which:

[0100] FIG. 1 is a front view of a full-face sealing cushion from the side of a patient interface portion of the sealing cushion;

[0101] FIG. 2 is a side view of the full-face sealing cushion of FIG. 1;

[0102] FIG. 3 is a top view of the full-face sealing cushion of FIGS. 1 and 2;

[0103] FIG. 4 is a front view of a nasal sealing cushion from the side of a patient interface portion of the sealing cushion;

[0104] FIG. 5 is a side view of the nasal sealing cushion of FIG. 4;

[0105] FIG. 6 is a top view of the nasal sealing cushion of FIGS. 4 and 5; and

[0106] FIG. 7 is a perspective view of a respiratory mask comprising the nasal sealing cushion of FIGS. 4-6.

[0107] A sealing cushion according to the present invention is illustrated in FIGS. 1-3.

[0108] The sealing cushion 5 is substantially triangular in nature, and is shaped so as to substantially surround a patient’s nasal and mouth regions and create a seal between a respiratory mask and a patient’s face. The sealing cushion 5 comprises an aperture 15 therethrough for receiving both a nasal region and a mouth region of a patient. The aperture 15 has a similar shape to that of the sealing cushion 5 in general, and is thus similar to that of the nasal and mouth region of a patient.

[0109] The sealing cushion 5 comprises a patient interface portion 10, a sidewall portion 12 and a mask connection interface 55. The patient interface portion 10 and the sidewall portion 12 are formed from one continuous membrane. The sidewall portion 12 extends from the mask connection interface 55 and is folded upon itself to form the patient interface portion 10 which is arranged to engage with a person’s face. Together, when in use, the patient interface portion 10, the sidewall 12 and a connected respiratory mask form an internal cavity within the sealing cushion 5.

[0110] This allows gas to be applied through the respiratory mask for the patient to inhale, and the seal formed by the patient interface portion 10 against the patient’s face prevents the gas from escaping, ensuring a more efficient inhalation of the gas by the patient.

[0111] The patient interface portion 10 and the sidewall portion 12 comprise a resiliently deformable membrane that extends substantially vertically outwards from the mask connection interface 55 (ie outwards from the page as viewed in relation to FIG. 1) to form the sidewall portion 12, and folds inwardly and in some places back on itself in order to create the patient interface portion 10, which is a compliant surface for engaging with a patient’s face. The surface of the patient interface portion 10 is deformable upon engagement with a patient’s face so as to create a sealed fit with the patient’s face.

[0112] The resiliently deformable membrane varies in thickness across the patient interface portion 10 and the sidewall portion 12, creating a plurality of portions of varying thicknesses. The variation in thickness extends across the internal surface of the patient interface portion 10 and/or the internal surface of the sidewall portion 12. That is, the external surfaces of the patient interface portion 10 and the sidewall portion 12 are one continuous surface. The portions are specifically arranged so as to provide the best seal possible when the patient interface portion 10 is pressed against a patient’s face during use, as well as to provide the best comfort possible to patients who can wear these masks over a long period of time.

[0113] For ease of description of the interrelation of the plurality of portions of varying thicknesses, the Figures are provided with axes, where the x axis represents the width of the sealing cushion 5 (ie cheek-to-cheek width when applied to a patient’s face), the y axis represents the length or height of the sealing cushion 5 (ie nose to chin length when applied to a patient’s face), and the z axis represents the depth of the sealing cushion 5 (ie outward from the face when applied to a patient’s face).

[0114] The patient interface portion 10 comprises a compliant nasal region 20, two nasal support regions 25 either side of the compliant nasal region 20, two cheek support regions 30 below each of the nasal support regions 25, a compliant chin region 35, a compliant inner member 40, two reinforced chin portions 45, and the sidewall portion 12 comprises two reinforced sidewall portions 50 and a nasal bridge support region 65 (see FIGS. 2 and 3).

[0115] The compliant nasal region 20 is positioned at the top of the patient interface portion and extends over the nasal bridge of the patient. The compliant nasal region 20 is a thinner portion of the patient interface portion, which allows the membrane to be particularly deformable in this area so as to comply with the patient’s nose shape and size.

[0116] The nasal support regions 25 are disposed at either side of the compliant nasal region 20 and extend between the compliant nasal region 20 and the cheek support regions 30 on the patient interface portion 10. The nasal support regions 25 are thicker portions of the patient interface region which provide rigidity to the sealing cushion against the sides of the patient’s nasal region, maintaining the general shape of the patient interface portion.

[0117] The cheek support regions 30 are disposed beneath each of the nasal support regions and extend between the nasal support regions 25 and the compliant chin region 35 on the patient interface portion 10. The cheek support regions are thicker than the compliant nasal region 20, but are thinner than the nasal support regions 25.

[0118] The reinforced chin portions 45 comprise additional portions formed on the internal surface of the cheek support regions 30. The reinforced chin portions 45 are disposed either side of the patient’s chin region, such that they are located at the base corners of the patient interface portion 10. The reinforced chin portions 45 are of a greater thickness than the compliant nasal region 20 and the cheek support regions 30, but a lesser thickness than the nasal support regions 25.

[0119] The compliant chin region 35 is disposed between the cheek support regions 30 in the central base region of the patient interface portion 10 and is configured to engage with the patient’s upper chin. The compliant chin region 35 is a thinner portion of the patient interface portion 10, having the same thickness as the compliant nasal region 20, which allows the membrane to be particularly deformable in this area so as to comply with the patient’s lower mouth and jaw shape and size.

[0120] The compliant inner member 40 extends around the entirety of the perimeter of the aperture 15 in the patient interface portion 10 and merges with the compliant nasal region 20 and the compliant chin region 35. The compliant inner member 40 is a thinner portion of the patient interface portion, having the same thickness as the compliant nasal region 20 and the compliant chin region 35. This allows the patient interface portion to deform inwardly when pressed against the patient’s face in use.

[0121] FIG. 2 illustrates the sealing cushion 5 of FIG. 1 viewed from a side angle. From this angle, the mask connection interface 55 can be seen. The mask connection interface 55 comprises a rim which extends around substantially the entire sealing cushion 5. The rim comprises a groove which extends around substantially all of the perimeter of the mask connection interface 55. The groove is dimensioned so as to receive a corresponding projection formed on the respiratory mask to be connected. The groove has portions of enlarged depth 60 located at the corners of the mask connection interface 55 ie the base corners and the apex of the sealing cushion 5. These reduced depth groove portions 60 are arranged such that corresponding outwardly protruding features formed on the respiratory mask can be received by the mask connection interface 55.

[0122] From this angle the reinforced sidewall region 50 can also be seen. The reinforced sidewall region 50 extends between the mask connection interface 55 and the cheek support region 30 in the z axis, and between the nasal support region 25 and the cheek support region 30 in the y axis. A reinforced sidewall region of the same shape, form and thickness can also be found on the opposite side of the patient interface portion 10, which cannot be seen from this view. That is, the patient interface portion 10 is completely symmetrical about a centreline in the y axis and in the y plane.

[0123] The reinforced sidewall region 50 is thicker than the reinforced chin portions 45, the cheek support regions 30, the compliant nasal region 20, the compliant chin region 35 and the compliant inner member 40, but is thinner than the nasal support regions 25.

[0124] The compliant nasal region 20 comprises a narrow band extending from the nasal bridge support region 65, approximately halfway up the sidewall portion 12 in the z direction, across the fold line between the patient interface portion 10 and the sidewall portion 12. The band begins at its widest, narrowing slightly in the x direction over the sidewall portion 12, before narrowing more dramatically between the fold line between the patient interface portion 10 and the sidewall portion 12. At the apex of the aperture 15 in the patient interface portion 10, the compliant nasal region 20 merges with the compliant inner member 40.

[0125] The nasal support regions 25 comprise lobes that extend between the compliant inner member 40, across the fold line between the patient interface portion 10 and the sidewall portion 12, to the mask connection interface 55. The entirety of each nasal support region 25, if the patient interface portion 10 and the sidewall portion 12 were laid flat, is substantially ear-shaped. That is, the portion of the nasal support region 25 on the patient interface portion 10 has an undulating edge that emulates the outer edge of an ear-shape.

[0126] Towards the top of the sealing cushion 5, nearest the compliant nasal region 20, each nasal support region 25 extends the full distance between the mask connection interface 55 and the compliant inner member. Moving away from the compliant nasal region 20 in the y direction, each nasal support region 25 reduces in width, and at its thinnest point extends only from the mask connection interface 55 to the fold line between the patient interface portion 10 and the sidewall portion 12. The diagonal line between the largest width and the smallest width of each nasal support region 25 is an undulating edge.

[0127] The cheek support regions 30 substantially follow the curvature of the sealing cushion 5 and the aperture 15. That is, on the patient interface 10, the cheek support regions 30 extend substantially downwards from the nasal support regions 25 and then follow the curvature of the corners of the sealing cushion 5 inwardly towards the compliant chin region 35. Similarly, on the sidewall portion 12, the cheek support regions 30 extend substantially downwards from the nasal support regions 25 and then follow the curvature of the corners of the sealing cushion 5 inwardly towards the compliant chin region 35 and the mask connection interface 55. The cheek support regions 30 begin approximately half way down the sidewall portion 12, and end at the bottom of the sidewall portion 12.

[0128] Towards the bottom of the sealing cushion, nearest the compliant chin region 35, each cheek support region 30 extends the full distance between the reinforced sidewall regions 50 and the compliant inner member 40. However, in an upper portion 32 of each cheek support region 30, once the reinforced sidewall portions 50 end, each cheek support region narrows in width and instead extends between the nasal support regions 25 and the compliant inner member 40. The upper portion 32 of each cheek support region 30 therefore gradually narrows in width from bottom to top in the y direction, the diagonal line between the largest width and the smallest width of the upper portion 32 comprising an undulating edge that corresponds to the undulating edge of the corresponding nasal support region 25.

[0129] The compliant chin region 35 comprises a substantially square shaped portion that extends across the fold line between the patient interface portion 10 and the sidewall portion 12. The compliant chin region 35 has a more gradual progression between the patient interface portion 10 and the sidewall portion 12 than the other regions of the sealing cushion 5, having less of a definitive fold line between the two.

[0130] The reinforced chin portions 45 comprise substantially square-shaped portions that extend across the folding line between the patient interface portion 10 and the sidewall portion 12. The reinforced chin portions have a width approximately the same as the width of the compliant nasal region 20.

[0131] The reinforced sidewall regions 50 substantially follow the curvature of the sealing cushion 5 and the aperture 15, and extend over the sidewall portion 12 substantially parallel to the cheek support region 30. That is, on the sidewall portion 12, the reinforced sidewall region 50 extend substantially downwards from the nasal support regions 25 and then follow the curvature of the corners of the sealing cushion 5 inwardly towards the mask connection interface 55. The reinforced sidewall portions 50 begin approximately halfway down the sidewall portion 12 (ie substantially in line with the start of the cheek support region 30) and end at the cheek support region 30.

[0132] The compliant inner member 40 substantially follows the curvature of the sealing cushion 5 and the aperture 15. The compliant inner member 40 has substantially the same width over its entire perimeter, aside from portions substantially adjacent the widest portions of the nasal support regions 25, which are slightly wider than the rest of the compliant inner member 40.

[0133] FIG. 3 illustrates the sealing cushion 5 of FIGS. 1 and 2 from the top of the sealing cushion 5. From this angle, the nasal bridge support region 65 can be seen. The nasal bridge support region 65 extends between the mask connection interface 55 and the compliant nasal region 20 in the z axis, and between the two nasal support regions 25 in the x axis.

[0134] The nasal bridge support region 65 is of the same thickness as the reinforced sidewall portions 50, that is, thicker than the reinforced chin portions 45, the cheek support regions 30, the compliant nasal region 20, the compliant chin region 35 and the compliant inner member 40, but thinner than the nasal support regions 25.

[0135] The nasal bridge support region 65 is positioned so that it is unlikely to make contact with a patient’s nasal bridge region in use, but so that it can provide support to the compliant nasal region 20. The nasal bridge support region 65 comprises a region having a width in the x direction greater than its length in the z direction. The width of the nasal bridge support region 65 in the x direction is substantially the same as the width in the x direction of the compliant nasal region 20. The nasal bridge support region 65 comprises concave edges in the x direction.

[0136] In this specific embodiment, each of the regions of the full-face sealing cushion 5 has the following thickness:

TABLE-US-00001 compliant nasal region 20 0.35 mm nasal support regions 25 2.5 mm cheek support regions 30 1.35 mm compliant chin region 35 0.35 mm compliant inner member 40 0.35 mm reinforced chin portions 45 Variable up to 1.93 mm reinforced sidewall regions 50 2.0 mm nasal bridge support region 65 2.0 mm

[0137] It will be appreciated that the thicknesses of the compliant nasal region 20, the compliant chin region 35 and the compliant inner member 40 may be the same or substantially the same, and that the thicknesses of the reinforced sidewall regions 50 and the nasal bridge support region 65 may be the same or substantially the same.

[0138] In alternative embodiments, it is anticipated that the thicknesses of each of the regions 20, 25, 30, 35, 40, 45, 50, 65 may be different, or even that the order of thicknesses of each of the regions 20, 25, 30, 35, 40, 45, 50, 65 may be different. However, the thickness of the compliant regions 20, 35, 40 will always be less than the remaining regions 25, 30, 45, 50, 65.

[0139] A nasal sealing cushion according to the present invention is illustrated in FIGS. 4-6.

[0140] The nasal sealing cushion 105 works in substantially the same way as the full-face sealing cushion 5 of FIGS. 1-3, but sealing over just the nose of a patient in use, rather than the nose and mouth of the patient, and is generally the same in nature as the sealing cushion 5 of FIGS. 1-3, aside from the obvious dimensional differences that result in the lower portion of the mask engaging with a patient’s upper lip region in use. Corresponding features are therefore labelled with similar reference numerals, and similarities between the cushions will not be re-described for conciseness. However, features of the nasal sealing cushion 105 that differ relative to the full-face sealing cushion 5 will be described below.

[0141] For ease of description of the interrelation of the plurality of portions of varying thicknesses, the Figures are provided with axes, where the x axis represents the width of the sealing cushion 105 (ie cheek-to-cheek width when applied to a patient’s face), the y axis represents the length or height of the sealing cushion 105 (ie nose to upper lip length when applied to a patient’s face), and the z axis represents the depth of the sealing cushion 105 (ie outward from the face when applied to a patient’s face).

[0142] The patient interface portion 100 comprises a compliant nasal region 120, two nasal support regions 125 either side of the compliant nasal region 120, two cheek support regions 130 generally below each of the nasal support regions 125, a compliant upper lip region 135, a compliant inner member 140, two reinforced upper lip portions 145, and the sidewall portion 112 comprises two reinforced sidewall portions 150. Each nasal support region 125 further comprises a reinforced nasal region 170, and each sidewall region 112 further comprises an upper reinforcing member 180 and a lower reinforcing member 190.

[0143] The nasal support regions 125 are disposed at either side of the compliant nasal region 20 and extend between the compliant nasal region 120 and a portion of the cheek support regions 130 on the patient interface portion 110.

[0144] The cheek support regions 130 are disposed generally beneath each of the nasal support regions 125 and extend between the nasal support regions 125 and the compliant upper lip region 135 on the patient interface portion 110. A portion of the cheek support regions 130 does extend adjacent to the nasal support regions 125, ie upwardly of the bottommost point of the nasal support region 125.

[0145] The reinforced upper lip portions 145 comprise additional portions formed on the internal surface of the cheek support regions 130. The reinforced upper lip portions 145 are disposed either side of the compliant upper lip region 135, such that they are located at the base corners of the nasal sealing cushion 105. The reinforced upper lip portions 145 have generally the same shape and form as the reinforced chin portions 45 of the full-face sealing cushion 5, both being reinforced subregions of the sealing cushion, but due to the dimensions of the nasal sealing cushion 105, are arranged to engage with the upper lip region of a wearer in use, rather than the chin region.

[0146] FIG. 5 illustrates the sealing cushion 105 of FIG. 4 viewed from a side angle. From this angle the reinforced sidewall region 150 can be seen. The reinforced sidewall region 150 extends between the mask connection interface 155 and the cheek support region 130 or the nasal support region 125 in the z axis, and between the compliant nasal region 120 and the base corner in the y axis. A reinforced sidewall region of the same shape, form and thickness can also be found on the opposite side of the nasal sealing cushion 105, which cannot be seen from this view. That is, the nasal sealing cushion 105 is completely symmetrical about a centreline in the y axis and in the y plane.

[0147] The nasal support regions 125 comprise lobes that extend from the reinforced sidewall region 150 across the fold line between the sidewall portion 112 and the patient interface portion 110, to the compliant inner member 140, or where the cheek support region 130 extends adjacent to the nasal support region 125, to the cheek support region 130

[0148] Towards the top of the sealing cushion 105, nearest the compliant nasal region 120, each nasal support region 125 extends the full distance between the reinforced sidewall region 150 and the compliant inner member 140. Moving away from the compliant nasal region 120 in the y direction, each nasal support region 125 reduces in width, and at its thinnest point extends only from the reinforced sidewall region 150 to just beyond the fold line between the patient interface portion 100 and the sidewall portion 112. The diagonal line between the largest width and the smallest width of each nasal support region 25 is a rounded edge.

[0149] From this angle, it can be seen that the upper reinforcing member 180 extends across the sidewall 112 between the reinforced nasal region 170 and the mask connection interface 155, and that the lower reinforcing member 190 extends across the sidewall 112 between the reinforced upper lip region 145 and the mask connection interface 155. In this respect, the upper reinforcing member 180 splits the reinforced sidewall region 150 into an upper section and a middle section, and the lower reinforcing member 190 splits the reinforced sidewall region 150 into a middle section and a lower section. Each of the upper reinforcing members 180 and the lower reinforcing members 190 is a generally rectangular portion having a constant width across its length. At the end of the upper reinforcing members 180 and the lower reinforcing members 190 nearest to the aperture 115, the upper reinforcing members 180 and the lower reinforcing members 190 transition into the reinforced nasal regions 170 and the reinforced upper lip regions 145 respectively.

[0150] The reinforced nasal regions 170 are positioned on the nasal support regions between the upper reinforcing members 180 and the aperture 115, and each consist of a plurality of projections that are raised relative to the underside of the nasal support regions 125, ie these portions have a greater thickness than the nasal support regions 125. In this embodiment, each reinforced nasal region 170 consists of six square-shaped projections and one larger square-shaped projection, though it will be understood that any number is possible. In this embodiment, the larger square-shaped projection is of a width and length approximately equal to two times the width and length of the smaller square-shaped projections.

[0151] The reinforced upper lip regions 145 are positioned on the cheek support regions 130 between the lower reinforcing members 190 and the aperture 115, and each consist of a plurality of projections that are raised relative to the underside of the cheek support regions 130, ie these portions have a greater thickness than the cheek support regions 130. In this embodiment, each reinforced upper lip region 145 consists of two smaller square-shaped projections and one larger square-shaped projection, though it will be understood that any number is possible. In this embodiment, the larger square-shaped projection is of a width and length approximately equal to two times the width and length of the smaller square-shaped projections

[0152] In this specific embodiment, each of the regions of the nasal sealing cushion 105 has the following thickness:

TABLE-US-00002 compliant nasal region 120 0.3 mm nasal support regions 125 1.0 mm cheek support regions 130 0.7 mm compliant upper lip region 135 0.3 mm compliant inner member 140 0.3 mm reinforced upper lip region 145 Variable up to 1.25 mm reinforced sidewall regions 150 2.0 mm reinforced nasal regions 170 Variable up to 1.9 mm upper reinforcing members 180 2.3 mm lower reinforcing members 190 2.25 mm

[0153] It will be appreciated that the thicknesses of the reinforced sidewall regions 150 and the thickest parts of the reinforced nasal regions 170 may be substantially the same, that the thicknesses of the upper reinforcing members 180 and the lower reinforcing members 190 may be substantially the same, and that all of the compliant nasal region 120, the compliant upper lip region 135 and the compliant inner member 140 may be the same or substantially the same.

[0154] In alternative embodiments, it is anticipated that the thicknesses of each of the regions 120, 125, 130, 135, 140, 145, 150, 170, 180, 190 may be different, or even that the order of thicknesses of each of the regions 120, 125, 130, 135, 140, 145, 150, 170, 180, 190 may be different. However, the thickness of the compliant regions 120, 135, 140 will always be less than the remaining regions 125, 130, 145, 150, 170, 180, 190.

[0155] As an example, FIG. 7 illustrates the nasal sealing cushion of FIGS. 4-6 as part of a respiratory mask assembly, generally designated 200. The mask assembly 200 comprises a mask shell 205, an elbow connector 210, and the nasal sealing cushion 105 described in relation to FIGS. 4-6. It will be appreciated that a similar mask shell, though of different dimensions, would engage in the same or a similar manner with the full-face sealing cushion of FIGS. 1-3.

[0156] The mask shell 205 is substantially triangular in nature, and is shaped so as to correspond to the mask shell interface portion 155 of the sealing cushion 105. The mask shell 205 is generally dome-shaped, such that the mask shell 205 has an internal cavity. A lip is located along each edge of the mask shell 205 so as to have a snap fit engagement with the groove of the mask connection interface 155 of the sealing cushion 105.

[0157] A pair of strap retaining formations 220 are located at lower left and right corners of the mask shell 205 and are each dimensioned so as to be received within a corresponding portion of enlarged depth of the groove disposed on the mask connection interface 155 of the sealing cushion 105. The pair of strap retaining formations 220 each extend laterally outwardly from the body of the mask shell 205. The plurality of strap retaining formations 220 are integral with the mask shell 205, and are formed as part of the same injection moulding process that is used to form the mask shell 205.

[0158] Each of the of strap retaining formations 220 comprise first and second arm-like portions. The first arm-like portion extends laterally outwardly from the mask shell 205, and the second arm like portion extends substantially orthogonally from the first arm-like portion in the same vertical plane. The second arm-like portion is curved in nature, such that a distal end of the second arm-like portion extends substantially towards the mask shell 205. Thus, each of the of strap retaining formations are hook-like in form.

[0159] A forehead support formation 225 is located at the uppermost corner of the triangularly shaped mask shell 205. The forehead support formation 225 is elongate and extends vertically outwardly from the mask shell 205. The forehead support formation 225 is integral with the mask shell 205 and is formed as part of the same injection moulding process as that which forms the mask shell 205.

[0160] The forehead support formation 225 is obliquely angled relative to the mask shell 205, so as to conform to the plane of a patient’s forehead. The forehead support formation 225 has a substantially rectangular cross section. The cross section of the forehead support formation 225 is not constant along its length, and the forehead support formation 225 is tapered towards a distal end.

[0161] The distal end of the forehead support formation 225 comprises a forehead rest 230. The forehead rest 230 is integral with the forehead support formation 225 and is formed as part of the same injection moulding process. The forehead rest 230 is substantially elliptical in form and is positioned such that its semi-major axis lies in a substantially vertical direction.

[0162] The mask assembly 200 further comprises headgear, not shown in the Figures, for fastening the mask assembly 200 to the head of a patient. The headgear includes a plurality of straps which are engageable with the forehead rest 230 and the strap retaining formations 220 of the mask shell.

[0163] The headgear comprises a plurality of retaining formations 215 for engaging the corresponding strap retaining formations 220 of the mask shell 205.

[0164] The retaining formations 215 comprise a substantially rectangular main body, and end toggles, of which only one end toggle is shown in the Figures. The width of the toggles is greater than the width of the main body, such that the shape of the retaining formations 215 resembles that of a bow. An end toggle is provided with an aperture, which receives a loop of a headgear strap. The end toggle is shaped so as to correspond with and be retained by the plurality of strap retaining formations 220 of the mask shell 205.

[0165] Similarly, a loop of a strap, or two straps, of the headgear may be received within a central slot of the forehead rest 230, so as to retain the mask assembly in place relative to the face of a patient.

[0166] The elbow connector 210 comprises a lower portion and an upper portion. The lower portion is substantially cylindrical in form and configured to receive a respiratory tube for supply of oxygen or pressurised gases to the patient via the mask assembly 200. The upper portion comprises first and second perpendicular limbs which form an elbow joint. The first limb is of a significantly shorter length than the second limb, such that the upper portion of the elbow connector 210 resembles a severely truncated “L-shape” or elbow. Both the lower and upper portions of the elbow connector 210 are hollow.

[0167] The first limb of the upper portion of the elbow connector 210 is received within an aperture of the mask shell 205 with a snap fit. The elbow connector 210 is rotatable around an axis that is orthogonal to the plane of the aperture of the mask shell 205, allowing a respiratory tube to be connected from any angle.

[0168] Additional features of such a respiratory mask assembly may be found in GB2521644, which is hereby incorporated by reference.