Sealing cushion with inner membrane

Abstract

A sealing cushion for a respiratory mask assembly has a patient interface portion having a resiliently deformable membrane for engagement with a patient's face, and an aperture formed therein for receiving a nasal and/or mouth region of the patient's face. An inner surface of the deformable membrane comprises a plurality of projections arranged in separate groups of projections positioned in a plurality of localized regions of the deformable membrane. The projections in each of the separate groups of projections are arranged such that each projection in the group of projections engages with an adjacent projection in the group of projections when the deformable membrane is deformed during engagement of the deformable membrane with the patient's face, in use, thereby providing the deformable membrane with an increased resistance to further deformation.

Claims

1. A sealing cushion for a respiratory mask assembly, the sealing cushion comprising: a patient interface portion having a resiliently deformable membrane for contact with a patient's face, and an aperture formed therein for receiving a nasal and/or mouth region of the patient's face, wherein an inner surface of the deformable membrane comprises a plurality of projections extending therefrom, the plurality of projections arranged in separate support formations positioned in three or more discrete regions on the inner surface of the deformable membrane, the projections in each of the separate support formations being arranged such that each projection in one support formation directly engages with an adjacent projection in the one support formation when the deformable membrane is deformed as a result of contact of the deformable membrane with the patient's face, in use, thereby providing the deformable membrane with an increased resistance to further deformation, wherein each of the separate support formations extend in a traverse direction across the deformable membrane, at least one of the separate support formations having at least two orthogonal grooves or channels between adjacent projections in the at least one of the separate support formation, wherein each of the separate support formations are separated from each other by a spacing that defines a region on the inner surface of the deformable membrane that does not comprise said plurality of projections.

2. The sealing cushion as claimed in claim 1, wherein a height of each projection of the plurality of projections is at least double a thickness of the deformable membrane.

3. The sealing cushion as claimed in claim 1, wherein a width and/or length of each projection of the plurality of projections is at least double a thickness of the deformable membrane.

4. The sealing cushion as claimed in claim 1, wherein two or more of the separate support formations are shaped, sized, or arranged to provide different levels of resilience and/or resistance to deformation.

5. The sealing cushion as claimed in claim 1, wherein one or more of the separate support formations are located in a nasal bridge region of the deformable membrane and comprise larger projections than one or more of the separate support formations located in corners of the deformable membrane located opposite the nasal bridge region.

6. The sealing cushion as claimed in claim 1, wherein the projections in each of the separate support formations extend in a traverse direction across substantially the entire deformable membrane.

7. The sealing cushion as claimed in claim 1, wherein the separate support formations are located either (i) on both sides of a nasal bridge region of the deformable membrane, (ii) in corners of the deformable membrane opposite the nasal bridge region, or (iii) both (i) and (ii).

8. The sealing cushion as claimed in claim 1, wherein a series of three or more adjacent projections in one or more of the support formations are adapted to be brought into direct engagement simultaneously, as the deformation of the deformable membrane increases.

9. The sealing cushion as claimed in claim 1, wherein a series of three or more adjacent projections in one or more of the support formations are adapted to be brought into direct engagement sequentially, as the deformation of the deformable membrane increases.

10. The sealing cushion as claimed in claim 1, wherein at least two projections of the plurality of projections in a first region of the deformable membrane are adapted to engage one another before engagement of at least two projections in a second region of the deformable membrane during engagement of the deformable membrane with the patient's face, in use.

11. The sealing cushion as claimed in claim 1, wherein one or more of the plurality of projections are tapered in a transverse direction, such that the one or more tapered projections reduce in width and/or height towards an inner edge of the deformable membrane that defines the aperture.

12. The sealing cushion as claimed in claim 1, wherein one or more of the plurality of projections are tapered in a circumferential direction, such that the one or more tapered projections of the plurality of tapered projections provide a graduated transition between regions of greater and regions of lesser resilience and/or resistance to deformation.

13. The sealing cushion as claimed in claim 1, wherein one or more of the plurality of projections is separated from an adjacent projection in the same support formation as the one or more of the plurality of projections by a V-shaped channel or groove.

14. The sealing cushion as claimed in claim 1, wherein the deformable membrane is curved in cross-section in a region of the deformable membrane that is deformed during use, and where the curvature increases when the deformable membrane is deformed by engagement with patient's face, the engagement between each of the projection in the one support formation with the adjacent projection in the one support formation being caused by the increase in curvature of the deformable membrane.

15. The sealing cushion as claimed in claim 1, wherein the deformable membrane comprises a single membrane.

16. The sealing cushion as claimed in claim 1, wherein the plurality of projections are integrally formed with the deformable membrane.

17. The sealing cushion as claimed in claim 1, wherein the plurality of projections arranged in the separate support formations positioned in the three or more discrete regions of the deformable membrane comprise first and second support formations positioned in a nasal bridge region of the deformable membrane, and one or more additional support formations positioned in (i) corners of the deformable membrane located opposite the nasal bridge region, (ii) below the nasal bridge region and centrally between corners of the deformable membrane, or (iii) both (i) and (ii).

18. The sealing cushion as claimed in claim 1, wherein each of the separate support formations have at least two orthogonal grooves or channels between adjacent projections in each of the respective separate support formations.

19. A respiratory mask assembly comprising a sealing cushion as claimed in claim 1.

20. A respiratory system comprising a respiratory mask assembly as claimed in claim 19.

21. The respiratory system as claimed in claim 20, wherein the respiratory system comprises a ventilator for delivering a supply of breathing gas to the respiratory mask assembly, and the ventilator is configured to supply positive pressure ventilation to a patient during at least a portion of a breathing cycle.

22. A sealing cushion for a respiratory mask assembly, the sealing cushion comprising: a patient interface portion having a resiliently deformable membrane for contact with a patient's face, and an aperture formed therein for receiving a nasal and/or mouth region of the patient's face, wherein an inner surface of the deformable membrane comprises a plurality of projections extending therefrom, the plurality of projections arranged in separate support formations positioned in a plurality of localized regions on the inner surface of the deformable membrane, the projections in each of the separate support formations being arranged such that each projection in one support formation directly engages with an adjacent projection in the one support formation when the deformable membrane is deformed as a result of contact of the deformable membrane with the patient's face, in use, thereby providing the deformable membrane with an increased resistance to further deformation, wherein each of the separate support formations extend in a traverse direction across the deformable membrane, at least one of the separate support formations having at least two orthogonal grooves or channels between adjacent projections in the at least one of the separate support formation, wherein each of the separate support formations are separated from each other by a spacing that defines a region on the inner surface of the deformable membrane that does not comprise said plurality of projections.

23. The sealing cushion as claimed in claim 22, wherein each of the separate support formations have at least two orthogonal grooves or channels between adjacent projections in each of the respective separate support formations.

Description

(1) A practicable embodiment of the invention is described in further detail below with reference to the accompanying drawings, of which:

(2) FIG. 1 is a perspective view of an embodiment of a sealing cushion according to the first aspect of the present invention;

(3) FIG. 2 is a rear view of the sealing cushion of FIG. 1;

(4) FIG. 3 is a left side view of the sealing cushion of FIG. 1;

(5) FIG. 4 is a cross-sectional view along the line A-A shown in FIG. 3;

(6) FIG. 5 is a perspective view of an embodiment of a mask assembly according to the second aspect of the present invention;

(7) FIG. 6 is an exploded perspective view of the mask assembly of FIG. 5;

(8) FIG. 7 is a front view of the mask assembly of FIG. 5;

(9) FIG. 8 is a cross-section along the line B-B shown in FIG. 7;

(10) FIG. 9 is an enlarged perspective view of a forehead rest which forms part of the mask assembly of FIG. 5;

(11) FIG. 10 is a perspective view of an elbow connector which forms part of the mask assembly of FIG. 5;

(12) FIG. 11 shows, counter-clockwise from top left: a left view of an elbow connector which forms part of the mask assembly of FIG. 5; a cross-section along the line C-C, a front view of an elbow connector which forms part of the mask assembly of FIG. 5; and a cross-section along the line D-D;

(13) FIG. 12 is an exploded perspective view of an alternative forehead rest for the mask assembly of FIG. 5 in a first configuration

(14) FIG. 13 is a perspective view of an alternative forehead rest for the mask assembly of FIG. 5 in a second configuration;

(15) FIG. 14 is a cross-section through the line E-E shown in FIG. 12 when the forehead rest is assembled.

(16) FIG. 15 is a schematic view of a respiratory system comprising a respiratory mask of the present invention.

(17) A mask assembly according to the present invention, generally designated 10, is shown in FIGS. 5 and 6. The mask assembly 10 comprises a mask shell 12, an elbow connector 14, and a sealing cushion 16.

(18) A sealing cushion according to the present invention is shown in FIGS. 1 to 3, which is formed by injection moulding in silicone.

(19) The sealing cushion 16 is substantially triangular in nature, and is shaped so as to substantially surround the nasal region of a patient. Thus, the sealing cushion 16 comprises an aperture 26, which has a shape similar to that of the nasal region of a patient.

(20) The sealing cushion 16 comprises a patient interface portion 18, a side wall portion 20 and a mask shell interface portion 22. The side wall portion 20 extends between, and connects, the patient interface portion 18 and the mask shell interface portion 22, such that an internal cavity is formed within the sealing cushion 16. The patient interface portion 18 comprises a deformable membrane 24. The aperture 26 is provided in the deformable membrane 24.

(21) The membrane 24 is of uniform thickness, which is less than that of the side wall portion 20. The side wall portion 20 is therefore of greater rigidity than the membrane 24, and acts to prevent the membrane 24 from contacting the mask shell interface portion 22 during use. The membrane 24 has a nasal bridge region 28 and a nostril region 30.

(22) The sealing cushion 16 comprises a plurality of support formations 32, 34, 36, 38, 40. Each of the plurality of support formations 32, 34, 36, 38, 40 extends transversely across an internal surface of the membrane 24. Each of the plurality of support formations 32, 34, 36, 38, 40 further extends transversely across an internal surface of the side wall portion 20.

(23) First 32 and second 34 support formations are disposed at either side of the nasal bridge region 28. The first 32 and second 34 support formations extend substantially transversely across the membrane 24 towards the aperture 26. The first support formation 32 is upraised from the interior surfaces of the membrane 24 and side wall 20 and has substantially the form of a trapezoidal prism. The first support formation 32 is formed with a plurality of substantially orthogonal grooves. Thus, the first support formation 32 effectively comprises a plurality of upraised projections 45. Each of the upraised projections 45 has a substantially trapezoidal cross section.

(24) The second support formation 34 has substantially the same form as the first support formation 32.

(25) In a similar manner, third 36 and fourth 38 support formations are disposed at either side of the nostril region 30, such that they are located at lower left and lower right corners of the membrane 24, and a fifth 40 support formation is disposed centrally between the third 36 and fourth 38 support formations, such that it is located at the lower centre of the membrane 24. Each of the third 36, fourth 38, and fifth 40 support formations have the same general form as the first 32 and second 34 support formations. However, the third 36, fourth 38, and fifth 40 support formations extend a shorter distance across the membrane 24 from the side wall 20.

(26) The mask shell interface portion 22 comprises a rim 44 which extends around substantially the entire sealing cushion 16. The rim 44 comprises a groove 46 which extends around substantially all of the perimeter of the mask shell interface portion 22. The groove 46 is dimensioned so as to receive a corresponding projection formed on the mask shell 12. The groove has portions of enlarged depth located along each major axis of the mask shell interface portion 22, but not at the corners of the mask shell interface portion 22, such that the corresponding projections formed on the mask shell 12 may be received with a snap fit.

(27) A mask shell 12 according to the present invention is shown more clearly in FIGS. 6, 7, and 8.

(28) The mask shell 12 is substantially triangular in nature, and is shaped so as to correspond to the mask shell interface portion 22 of the sealing cushion 16. The mask shell 12 is generally dome-shaped, such that the mask shell 12 has an internal cavity.

(29) A mask shell aperture 56 is located at the apex of the dome-shaped mask shell 12, and is substantially circular in nature. A frontal ridge 52 is upstanding from an exterior surface of the mask shell 12, and is disposed circumferentially about the mask shell aperture 56. The frontal ridge 52 has a substantially rectangular cross-section.

(30) A rearward ridge 54 extends rearwardly from the peripheral edge of the mask shell 12. The rearward ridge 54 extends into the mask shell interface portion 22 of the sealing cushion 16 when assembled. The rearward ridge 54 has a substantially rectangular cross section, and has a width which is substantially the same as that of the groove 46 that is present on the mask shell interface portion 22 of the sealing cushion 16.

(31) A plurality of clip projections 60 are integrally formed with the rearward ridge 54, and are located along each edge of the mask shell 12, but are not present at the corners. The plurality of clip projections 60 each have a substantially rectangular cross section, and each of the plurality of clip projections 60 have a width which is greater than the width of the rearward ridge 54. Each of the plurality of clip projections 60 is dimensioned so as to be received within a corresponding portion of enlarged depth of the groove disposed on the mask shell interface portion 22 of the sealing cushion 16.

(32) A retaining formation 58 comprises an upstanding projection, and is disposed centrally on the upper circumference of the first frontal ridge 52. This retaining formation 58 is adapted to engage a corresponding recess in the elbow connector 14, when the elbow connector 14 is orientated with its distal end directed towards the top of the patient's head. This may enable a patient to maintain a connected respiratory tube over the top of their head, if they find this a more comfortable position to sleep.

(33) A pair of strap retaining formations 62 are located at lower left and right corners of the mask shell 12. The pair of strap retaining formations 62 each extend laterally outwardly from the body of the mask shell 12. The plurality of strap retaining formations 62 are integral with the mask shell 12, and are formed as part of the same injection moulding process that is used to form the mask shell 12.

(34) Each of the of strap retaining formations 62 comprise first 68 and second 70 arm-like portions. The first arm-like portion 68 extends laterally outwardly from the mask shell 12, and the second arm like portion 70 extends substantially orthogonally from the first arm-like portion 68 in the same vertical plane. The second arm-like portion 70 is curved in nature, such that a distal end of the second arm-like portion 70 extends substantially towards the mask shell 12. Thus, each of the of strap retaining formations 62 are hook-like in form.

(35) A forehead support formation 64 is located at the uppermost corner of the triangularly shaped mask shell 12. The forehead support formation 64 is elongate, and extends vertically outwardly from the mask shell 12. The forehead support formation 64 is integral with the mask shell 12 and is formed as part of the same injection moulding process as that which forms the mask shell 12.

(36) The forehead support formation 64 is obliquely angled relative to the mask shell 12, so as to conform to the plane of a patient's forehead. The forehead support formation 64 has a substantially rectangular cross section. The cross section of the forehead support formation 64 is not constant along its length, and the forehead support formation 64 is tapered towards a distal end.

(37) A close-up view of the distal end of the forehead support formation 64 is shown in FIG. 9. The distal end of the forehead support formation 64 comprises a forehead rest 74. The forehead rest 74 is integral with the forehead support formation 64, and is formed as part of the same injection moulding process. The forehead rest 74 is substantially elliptical in form, and is positioned such that its semi-major axis lies in a substantially vertical direction.

(38) The forehead rest 74 comprises a central slot 76 and a plurality of apertures 78. The central slot 76 is substantially rectangular in form, and extends across substantially all of the semi-major axis of the forehead rest 74. Thus, the forehead rest 74 has a hollow central portion in the form of central slot 76, and a rim 80.

(39) The plurality of apertures 78 are located on the rim 80, and are substantially rectangular in form. The width of the central slot 76 is greater than twice the width of each of the plurality of apertures 78. Each of the plurality of apertures 78 are disposed centrally around the rim 80.

(40) A removable forehead spacer 106 is substantially elliptical in form, and is positioned such that its semi-major axis lies in a substantially vertical direction.

(41) The forehead spacer 106 comprises a central slot 118 and a plurality of spigots 120. The central slot 118 is substantially rectangular in form, and extends across substantially all of the semi-major axis of the forehead spacer 106. Thus, the forehead spacer 106 has a hollow central portion in the form of central slot 118, and a rim 122.

(42) The plurality of spigots 120 are located on the rim 122, and are substantially rectangular in form. The width of the central slot 118 is greater than twice the width of each of the plurality of spigots 120. Each of the plurality of spigots 120 are disposed centrally around the rim 122. The plurality of spigots 120 are shaped so as to be inserted into the plurality of apertures 78 disposed on the forehead rest 74 with a snap fit.

(43) The forehead spacer 106 is removable from engagement with the forehead rest 74, and thus provides a way of accommodating a wide variety of patients that have different sized foreheads. In particular, the mask may be used with or without the forehead spacer 106, depending on the preference of the patient. The forehead spacer 106 is keyed so that it can only be assembled in the correct orientation.

(44) An alternative forehead support formation 126 and forehead rest 132 are shown in FIGS. 12, 13 and 14.

(45) A distal end of the forehead support formation 126 comprises a bar 130, and a forehead rest 132. The bar 130 is substantially cylindrical in form, and is orthogonal to the forehead support formation 126. The bar 130 is wider than the distal end of the forehead support formation 126, such that the ends of the bar 130 project orthogonally outwardly from the distal end of the forehead support formation 126.

(46) The forehead rest 132 is substantially cuboidal in form. The forehead rest 132 comprises first 134 and second 136 channels located on opposing sides the forehead rest 132. Both the first 134 and second 136 channels extend across substantially all of the length of the forehead rest. Both of the first 134 and second 136 channels have a width that is approximately one third of the width of the forehead rest 132. Both the first 134 and the second 136 channels are located centrally on the forehead rest 132. The first 134 and second 136 channels have different depths, and the first channel 134 is deeper than the second channel 136.

(47) The first channel 134 comprises a plurality of sidewalls 138. Each sidewall 138 comprises a recess 140. The recesses 140 are substantially cylindrical in form. The recesses 140 are located centrally along the first channel 134. The diameter of each recess 140 is substantially the same as that of the diameter of the bar 130. Thus, the bar 130 may be located within the plurality of recesses 140, such that the forehead rest 132 is held in place. The forehead rest 132 is thereby rotatable around the bar 130.

(48) The first channel 134 further comprises a base wall. The base wall comprises first 144 and second 146 portions. The first portion 144 extends across slightly less than half of the length of the first channel 134. The second portion 146 extends across the remainder of the length of the first channel 134.

(49) The first portion 144 is tapered, such that the depth of the first channel 134 is greater at a first peripheral edge of the forehead rest 132 than it is at the central region of the first channel 134. The second portion is tapered, such that the depth of the first channel 134 is greater at an opposing peripheral edge of the forehead rest 132 than it is at the central region of the first channel 134. The angle of the taper of the first portion 144 is greater than the angle of the taper of the second portion 146. The base wall thus has the form of a scalene triangle.

(50) The second channel 136 comprises a plurality of sidewalls. Each sidewall 144 comprises a recess 147. The recesses 147 are substantially rectangular in form, and extend across substantially all of the depth of the second channel 136.

(51) When the forehead rest 132 is initially located upon the bar 130, the first portion 144 of the base wall is located such that it is in engagement with a rear surface 148 of the forehead support formation 126. This is the first configuration. The forehead rest 130 may be rotated around the bar 130, such that the second portion 146 of the base wall is in engagement with a front surface 150 of the forehead support formation. This is the second configuration.

(52) The taper of the first 144 and second 146 portions of the base wall is such that the forehead rest 132 extends rearwardly by a greater distance when it is in the first configuration than when the forehead rest 132 is in the second configuration. Thus, the forehead rest is adjustable in order to accommodate patients having a wide variety of forehead sizes.

(53) An elbow connector 14 according to the present invention is shown in FIGS. 10 and 11.

(54) The elbow connector 14 comprises a lower portion 82 and an upper portion 84. The lower portion 82 is substantially cylindrical in form. Both the lower 82 and upper 84 portions are hollow. The upper portion 84 comprises first 86 and second 88 perpendicular limbs. The second limb 88 is of a significantly shorter length than the first limb 86, such that the upper portion 84 of the elbow connector 14 resembles a severely truncated “L-shape” or elbow.

(55) The first limb 86 interfaces with the second limb 88 at a region that is disposed along a substantially central axis of the first limb 86. Thus, approximately a radius of the first limb 86 extends rearwardly underneath the second limb 88. The elbow connector 14 may thereby protrude outwardly from a mask shell 12 by a distance that is significantly less than those elbow connectors known in the prior art. A frontal surface 90 of the first limb 86 is tapered, such that the frontal surface 90 curves towards the interface region. The tapered nature of the first limb 86 gives the interface between the first 86 and second 88 limbs a substantially circular appearance.

(56) The first limb 86 comprises a plurality of apertures 92. The apertures 92 are located on the frontal surface 90, and are substantially rectangular in form. The apertures 92 are disposed in a series, in a semi-circular arrangement around the interface between the first 86 and second 88 limbs. The apertures 92 are thereby in fluid communication with both the first 86 and second limbs 88, and function as exhalation vents for the elbow connector 14.

(57) The first limb 86 comprises a resiliently deformable rim 87, which engages the corresponding frontal ridge 52 of the mask shell 12.

(58) The second limb 88 is substantially cylindrical in form. The second limb 88 comprises a peripheral upstanding rim 94. The peripheral upstanding rim 94 extends around substantially the entirety of the circumference of the second limb 88. The diameter of the second limb 88 is substantially the same as the diameter of the aperture 56 of the mask shell 12.

(59) The elbow connector 14 further comprises a plurality of quick release clips 96. The quick release clips 96 are elongate in form, and are disposed upon opposing sides of the elbow connector 14. The clips 96 extend between the lower portion 82 of the elbow connector 14, and the first limb 86 of the upper portion 84 of the elbow connector. Opposing ends of the quick release clips 96 are attached to the elbow connector 14, such that substantially all of the body of the quick release clips 96 is upstanding from the elbow connector 14.

(60) Each of the plurality of quick release clips 96 comprises a connecting formation 103. The connecting formation 103 takes the form of a circumferentially extending protrusion disposed in a lower region of the quick release clip 96. The connecting formation 103 is shaped to releasably retain a respiratory tube connector and/or any other such appropriate respiratory circuit component. An end portion of a respiratory tube can be advanced over the plurality of quick release clips 96, until a corresponding recess of the end portion engages the connecting formation 103.

(61) The quick release clip 96 comprises a series of channels 100 and ridges 102, such that the quick release grip comprises a grip formation. Each grip formation is formed of a resiliently deformable material. Thus, each grip formation may be depressed upon application of pressure by a user.

(62) In order to release the respiratory tube, the grip formations are depressed, thereby depressing the resiliently deformable connecting formation 103 at the same time, and the respiratory tube may be simply pulled away.

(63) The mask assembly 10 further comprises headgear, not shown in the Figures, for fastening the mask assembly 10 to the head of a patient. The headgear includes a plurality of straps which are engageable with the forehead rest 74 and strap retaining formations 62 of the mask shell.

(64) The headgear comprises a plurality of retaining formations 110 for engaging the corresponding strap retaining formations 62 of the mask shell 12.

(65) The retaining formations 110 comprise a substantially rectangular main body 112, and end toggles 114, of which only one end toggle 114 is shown in the Figures. The width of the toggles 114 is greater than the width of the main body 112, such that the shape of the retaining formations 110 resembles that of a bow. An end toggle 114 is provided with an aperture, which receives a loop of a headgear strap. The end toggle 114 is shaped so as to correspond with, and be retained by the plurality of strap retaining formations 62 of the mask shell 12.

(66) Such a toggle-like arrangement allows the headgear strap to be securely retained, whilst also allowing for quick and easy removal.

(67) Similarly, a loop of a strap, or two straps, of the headgear may be received within the central slot 76 of the forehead rest 74, so as to retain the mask assembly in place relative to the face of a patient.

(68) To assemble the parts of the mask assembly 10, the groove 46 and clip receiving formations 48 of the sealing cushion 16 are aligned with the ridge 54 and clip projections 60 of the mask shell 12. The ridge 54 and clip projections 60 are received within the groove 46 and clip receiving formations 48, respectively, with a snap fit.

(69) The second limb 88 of the elbow connector 14 is received within the aperture 56 of the mask shell 12 with a snap fit. The elbow connector 14 is rotatable around an axis that is orthogonal to the plane of the aperture 56 of the mask shell.

(70) When in use, the sealing cushion 16 is located over the nasal region of a patient. The toggles 114 are received within the strap receiving formations 62, and the headgear assembly is positioned at the rear of a patient's head, such that the strap acts so as to retain the mask assembly 10 in a desired position. Thus, the mask assembly 10 urges the sealing cushion 16 against the face of a patient, ensuring that an airtight seal is formed.

(71) The forehead spacer 106 may optionally be connected to the forehead rest 74.

(72) A respiratory tube 124 is connected to the elbow connector 14, such that a lip 126 of the respiratory tube 124 is retained by a channel 100 of the connecting formation of the quick release clips 96.

(73) The respiratory tube 124 allows a flow of oxygen or pressurised gases to be provided to the mask assembly 10, which may then be inhaled by the patient.

(74) Referring now to FIG. 15, a respiratory system 152 comprising respiratory mask assembly 10 is shown schematically. The respiratory system 152 may comprise a ventilator 154 for delivering a supply of breathing gas to the respiratory mask assembly 10 through respiratory tube 124, such that breathing gas may be inhaled by a patient. The ventilator 154 may be a mechanical ventilator. The ventilator may be configured to supply positive pressure ventilation to a patient during at least a portion of a breathing cycle. The ventilator 154 may be configured to supply continuous positive airway pressure, also known as CPAP, to a patient. Thus, the respiratory system 152 may be configured to treat patients suffering from sleep apnea or the like.