CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit under 35 U.S.C. § 119(d) of U.S. Provisional Application No. 61/289,641, filed on December 23, 2009, and of U.S. Provisional Application No. 61/391,514, filed on October 8, 2010, each of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to improved patient interface components, particularly but not solely, for use in delivering artificial respiration therapy to patients. In particular, the invention relates to interfaces and to headgear that is used to secure interfaces to a patient

Description of the Related Art

[0003] In the art of respiration devices, there are a variety of respiratory interfaces that cover the nose and/or mouth of a patient in order to provide a seal around the nasal and/or oral areas of the face such that gas may be provided at positive pressure within the interface for consumption by the patient.

[0004] The interfaces must provide an effective seal against the face to reduce the likelihood of significant leakage of the respiratory gas being supplied. In many interfaces, a good seal often is attained only with considerable discomfort for the patient, with temporary success and/or with significant time spent fitting the interface to the patient.

[0005] With respect to the discomfort for the patient, this problem is most crucial in acute care medical environments. In such environments, the patient will be required to wear the interface continuously for hours or perhaps even days. If significant discomfort is experienced, the patient will not willingly tolerate the mask for the desired long durations.

[0006] In many constructions, even a good seal can be temporary due to an inability to seal effectively when the face of the patient becomes distorted. For example, when the patient is sleeping on a side, one side of the headgear may be pulled tight while the other side becomes loose. This asymmetric loading can twist the axis of the interface relative to the axis of the head due to the net torque from the headgear and any associated breathing tube. The twisting of the axis can result in leakage on one side of the interface. In addition, a side-sleeping patient may also distort the facial contours (e.g., in the nasal area) around the seal, which may lead to further leakage.

[0007] Finally, in acute care settings, the speed with which respiratory treatment can be established is important. Accordingly, with some headgear configurations, the ability to rapidly establish a satisfactory seal has been identified as an area in which current configurations could be improved.

SUMMARY OF THE INVENTION

[0008] It has been found that improvements can be made to both sealing of the interface to the face of the patient and securing the interface to the face of the patient with headgear.

[0009] Because the interface may be worn for prolonged periods in a hospital for example or when sleeping, comfort preferably should be maximized while also maintaining sufficient pressure on the interface to provide proper location and an adequate seal against the face, thereby reducing the likelihood of significant leaks. For example, any leakage preferably is less than about 15 L/min. In a hospital setting, it is also possible that a patient will not be conscious while wearing the interface. Added comfort can also increase the patient's compliance with treatment and results in better outcomes generally.

[0010] It is preferable that the interface and associated headgear is as easy as possible to put on and take off correctly. In particular, it is also desirable for a single headgear design to accommodate a wide range of patient head sizes, shapes and hair style types, while still being simple to work. This is especially the case in a hospital setting where staff are regularly fitting and removing patient interfaces and associated head gear. Desirably, the interface also accommodates various facial shapes and sizes.

[0011] From the patient's viewpoint, the interface also should provide certain advantages where possible. For example, the patient may desire to wear glasses such that clearance above the nasal region can be important. In addition, the patient may desire to talk to people and, therefore, advances in the interface that can improve the ability to be heard without removing the interface can be important. Furthermore, the patient generally prefers to not have the interface intrude in a significant manner into the field of vision. Thus, a lower profile interface is desirable. Finally, from a comfort standpoint, the patient would desire an interface and headgear configuration that reduces gas leaks that are

directed toward the eyes and that has a reduced smell of materials while also having a lower noise level.

[0012] Clinically, the healthcare provider desires that, the well-sealing interface provide generally even interface pressure distribution on the skin to reduce the likelihood of point loading or excessive pressure gradients. Such a feature can reduce the likelihood of irritation to the skin of the patient. In addition, flushing of carbon dioxide to reduce the likelihood of rebreathing of carbon dioxide is desirable.

[0013] It is an object of the present invention to provide an improved patient interface and/or an improved headgear arrangement for securing a patient interface to a patient or to at least provide the public and medical profession a useful choice.

[0014] In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussion. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

[0015] The term "comprising" as used in this specification means "consisting at least in part of." When interpreting each statement in this specification that includes the term "comprising," features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner.

[0016] Certain embodiments of this invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

[0017] The invention consists in the foregoing and also envisages constructions of which the following gives examples only.

[0018] In one aspect, the present invention may broadly be said to consist in an interface comprising a mask, headgear, an adjustment line, an upper sliding connection between the adjustment line and an upper portion of the mask, a lower sliding connection between the adjustment line and a lower portion of the mask, a left sliding connection

between the adjustment line and a left side portion of the headgear, a right sliding connection between the adjustment line and a right side portion of the headgear, the adjustment line thus forming connections between the left side portion of the headgear and the upper and lower portions of the mask and the right side portion of the headgear and the upper and lower portions of the mask, and a clasp, clamp or other adjustment mechanism for securing at least a first portion of the adjustment line relative to a second portion of the adjustment line (either directly or indirectly) with the path of the line between the first and second portions including the upper, lower, left and right side connections, such that the length of the path of the adjustment line may be altered.

[0019] According to a further aspect, the adjustment line passes across the outside of either the upper portion of the mask, the lower portion of the mask or both.

[0020] According to a further aspect, the headgear includes upper left side attachment portion and lower left side attachment portion, upper right side attachment portion and lower right side attachment portion, and the adjustment line passes through the upper and lower attachment portions of each of the left side and right side portions of the headgear.

[0021] According to a further aspect, the interface includes at least two sliding connections between the attachment line and the lower mask portion.

[0022] According to a further aspect, the interface at least two sliding connections between the attachment line and the upper mask portion.

[0023] According to a further aspect, the interface a clasp holding the adjustment line at two points such that the adjustment line forms a closed loop.

[0024] According to a further aspect, the first and second portions of the adjustment line pass through the clasp, and drawing either or both ends through the clasp reduces the length of the loop, and the sliding connections to the mask and headgear distribute this tightening around the loop.

[0025] According to a further aspect, the clasp, clamp or adjustment mechanism releases the adjustment line or allows the adjustment line to pass through it upon application of tension on the adjustment line above a threshold (the threshold limiting the tension on the adjustment line to a useful range of tension).

[0026] According to a further aspect, the locations of the sliding connections on the mask are such that the projected area of the mask above the upper sliding

connection and the projected area of the mask below the lower sliding connection are substantially equal.

[0027] According to a further aspect, the adjustment line is substantially non extensile.

[0028] According to a further aspect, one or more of said sliding connections associated with said mask includes a pulley wheel engaging with said adjustment line.

[0029] According to a further aspect, one or more of said sliding connections associated with said headgear includes a pulley wheel engaging with said adjustment line.

[0030] According to a further aspect, said adjustment line is wholly or partially enclosed in a tube allowing said closed loop.

[0031] According to a further aspect, said clasp, clamp or other adjustment mechanism is:

[0032] a) a jam cleat

[0033] b) a cam cleat

[0034] c) linear ratchet ski binding type mechanism

[0035] d) ratchet and release adjustment wheel.

[0036] In another aspect, the present invention may broadly be said to consist in an interface for supplying gases to a patient comprising a seal for contacting the user's face on an inside side, the seal contacting the face around the mouth and nose of the wearer, wherein the outside surface of the interface being shaped to include a substantial reproduction of at least one human facial feature.

[0037] According to a further aspect, the outside surface of the interface includes the reproduction of a human nose.

[0038] According to a further aspect, the seal is part of a seal member formed from a soft compliant material, the interface includes a stiffer support member forming part of the outside surface of the interface and at least one facsimile of a human facial feature is formed as part of the seal member.

[0039] According to a further aspect, the support member is flexible and the periphery of the support member can conform to the facial contour of the wearer.

[0040] According to a further aspect, the seal member includes a seal portion which contacts the user's face and an enclosing portion which contacts the inside surface of the supporting member, a seal portion contacting the inside surface of the supporting member being fully or substantially complete but for an aperture sufficient to supply breathing gases.

[0041] According to a further aspect, the interface includes a connector sealed to the aperture of the seal member.

[0042] According to a further aspect, the outer perimeter of the support member includes a scallop or notch and the human facial feature of the seal member protrudes through the notch.

[0043] According to a further aspect, the seal member includes a radially inward projecting sealing flap around substantially the entire perimeter of the seal member, wherein the sealing flap also contacts the face first during donning of the interface.

[0044] According to a further aspect, the support member includes attachments for headgear for supporting the interface on a user.

[0045] According to a further aspect, the support member is ergonomically contoured for holding in the hand.

[0046] According to a further aspect, the facial feature comprises a human nose, the seal member extends to cover the wearer's nose and upper cheeks, cheekbones and the upper perimeter of the support member extends transversely across the upper lip below the nose, upwardly alongside each nostril and transversely away from the nose at each side, above the level of the nostrils.

[0047] According to a further aspect, the support body includes an opening substantially aligned with the aperture of the seal member, the opening of the support body being larger than aperture of the seal member.

[0048] According to a further aspect, the support member and the seal member each include a chin portion, at least the chin portion of the seal member extending under the chin of the wearer in use.

[0049] According to a further aspect, said seal is an inflating seal.

[0050] According to a further aspect, said stiffness support member includes a bridge portion extending at least partially over said seal member in the region of the bridge of said reproduction of a human nose.

[0051] According to a further aspect, said interface further includes a breathing tube connection port, and wherein said connection port is fitted to said seal member.

[0052] In another aspect, the present invention may broadly be said to consist in a respiratory mask comprising a soft compliant seal member adapted to cover a users nose and mouth, and contact a users face to seal along at least a sealing edge, a support member adjacent to and supporting said seal member, wherein at least an outer portion of said support member comprises a plurality of displaceable members movable with respect to at least an inner portion of said support member.

[0053] According to a further aspect, said inner portion of said support member includes a hub portion connected to said seal and said displaceable members are cantilevered such that they branch outward from said inner hub toward said peripheral sealing edge of said seal member.

[0054] According to a further aspect, said displaceable members are movable with respect to one another.

[0055] According to a further aspect, said respiratory mask includes a further support member adjacent to and supporting said support member or said seal member, wherein at least an outer portion of said further support member comprises a plurality of displaceable members movable with respect to at least an inner portion of said further support member

[0056] According to a further aspect, the movement of said displaceable members is predominantly in a front to back direction with respect to a users face when wearing said respiratory mask.

[0057] According to a further aspect, one or more of said displaceable members further includes one or more compliant members associated with a free end of said displaceable member.

[0058] According to a further aspect, said compliant member is a compressible hoop.

[0059] According to a further aspect, said compliant member is an articulated elastic beam.

[0060] According to a further aspect, said compliant member is a compressible foam material.

[0061] According to a further aspect, said support member or said further support member includes a semi-rigid reinforcing rib that substantially stiffens said support member or said further support member in a direction.

[0062] According to a further aspect, said reinforcing rib and said direction is substantially aligned with a mid sagittal plane of said user when wearing said mask.

[0063] In another aspect, the present invention may broadly be said to consist in an interface substantially as herein described with reference to any one or more of the drawings.

[0064] In another aspect, the present invention may broadly be said to consist in an interface comprising a mask, headgear, a connection between said mask and said headgear comprising an elastic extensile element and a substantially non-extensile element arranged in parallel, a adjustment mechanism operable to adjust the length of the non-extensile element of the connection.

[0065] According to a further aspect, said connection is adapted to in use extend from a first side of said mask, around the back of a user's head, to a second side of said mask.

[0066] According to a further aspect, the mask has left and right sides, and the headgear has left and right sides, said connection includes a first connection between the left side of the mask and the left side of the headgear, and a second connection between the right side of the mask and the right side of the headgear, the first and second connections comprising an elastic extensile element and a substantially non-extensile element arranged in parallel, a first adjustment mechanism operable to adjust the length of the non-extensile element of the first connection, and a second adjustment mechanism operable to adjust the length of the non-extensile element of the second connection.

[0067] According to a further aspect, said interface further comprises a third connection between the left side of the mask and the left side of the headgear, and a fourth connection between the right side of the mask and the right side of the headgear, the third and fourth connections comprising an elastic extensile element and a substantially non-extensile element arranged in parallel, a third adjustment mechanism operable to adjust the length of the non-extensile element of the third connection, and a fourth adjustment mechanism operable to adjust the length of the non-extensile element of the fourth connection.

[0068] According to a further aspect, the first and second connections connect between an upper portion of the mask and an upper portion of the headgear, and the third and fourth connections connect between a lower portion of the mask and a lower portion of the headgear.

[0069] According to a further aspect, the first and second adjustment mechanisms are operable to adjust the length of the non-extensile elements of the first and second connections.

[0070] According to a further aspect, the third and fourth adjustment mechanisms are operable to adjust the length of the non-extensile elements of the third and fourth connections.

[0071] According to a further aspect, all the adjustment mechanisms are located on the mask.

[0072] According to a further aspect, all the adjustment mechanisms are of a locking type having at least two modes, wherein in a first locking mode the length of said non-extensile element cannot be lengthened, and in a second un-locking mode the length of said non-extensile element can be lengthened.

[0073] According to a further aspect, the length of said non-extensile element can be shortened when said locking mechanism is in said locking mode.

[0074] According to a further aspect, the first and second connections pass around the side of a users head and are located above a users ear, and the third and fourth connections pass around the side of a users head and are located below a users ear.

[0075] According to a further aspect, the adjustment mechanisms are each one of:

[0076] a. a friction clasp

[0077] b. a ladder lock

[0078] c. a buckle

[0079] d. a ratchet

[0080] e. a clamp

[0081] f. a cam cleat

[0082] According to a further aspect, the elastic element and non-extensile element of the first connection are attached to the mask at a substantially coinciding attachment location, and the elastic element and non-extensile element of the second connection are attached to the mask at a substantially coinciding attachment location.

[0083] According to a further aspect, the elastic element and non-extensile element of the third connection are attached to the mask at a substantially coinciding attachment location, and the elastic element and non-extensile element of the fourth connection are attached to the mask at a substantially coinciding attachment location. [0084] According to a further aspect, the elastic element and non-extensile element of the first connection are attached to the headgear at a substantially coinciding attachment location, and the elastic element and non-extensile element of the second connection are attached to the headgear at a substantially coinciding attachment location.

[0085] According to a further aspect, the elastic element and non-extensile element of the third connection are attached to the headgear at a substantially coinciding attachment location, and the elastic element and non-extensile element of the fourth connection are attached to the headgear at a substantially coinciding attachment location.

[0086] According to a further aspect, the length of the elastic extensile elements of the connections can be stretched to between approximately 1.5 times and 3 times their un-stretched length.

[0087] According to a further aspect, the length of the elastic extensile elements of the connections can be stretched to approximately double their un-stretched length.

[0088] According to a further aspect, the length of the elastic extensile elements of the connections are not adjustable other than by stretching of the material.

[0089] According to a further aspect, the retention force provided by the elastic extensile elements of the connections is sufficient to retain the mask on a user's face during fitting.

[0090] According to a further aspect, the retention force provided by the elastic elements of the connections is sufficient to assist sealing of the mask during use.

[0091] According to a further aspect, the mask is one of:

[0092] g. a nasal mask,

[0093] h. an oral mask,

[0094] i. an oral nasal mask (full face)

[0095] j. nasal pillows

[0096] k. oral mask including nasal prongs

[0097] 1. nasal cannula

[0098] According to a further aspect, the elastic elements and non-extensile elements of each respective connection are integrated one within the other.

[0099] According to a further aspect, the elastic elements of each connection include a passage within running a substantial length thereof, and the respective non-extensile elements are located in said passage.

[0100] According to a further aspect, the non-extensile elements of each respective connection are also configured to resist compressive forces along their length.

[0101] In another aspect, the present invention may broadly be said to consist in an interface comprising a mask, headgear, a connection between the mask and the headgear having a first adjustable mode wherein the length of the connection can be adjusted and a second fixed mode wherein the length of the connection cannot be substantially increased.

[0102] According to a further aspect, said connection comprises a right side connection and a left side connection, and wherein the length of the right side connection and the left side connection can each be adjusted in the first mode, and the length of the right side connection and the left side connection cannot be substantially increased in the second fixed mode.

[0103] According to a further aspect, the adjustment of the length of the connection is via a locking mechanism having at least two modes, wherein in a first locking mode the length of the connection cannot be lengthened, and in a second unlocking mode the length of said connection can be lengthened.

• [0104] According to a further aspect, the length of said connection can be shortened when said locking mechanism is in said locking mode.

[0105] According to a further aspect, each connection comprises an elastic extensile element configured to provide a retention force to hold the mask on a wearers face in said first locking mode.

[0106] According to a further aspect, each connection comprises an elastic extensile element configured to provide a retention force to hold the mask on a wearers face in said second un-locking mode.

[0107] According to a further aspect, the headgear is less extensible than the elastic elements of the connections.

[0108] According to a further aspect, the headgear is less extensible than the connections.

[0109] In another aspect, the present invention may broadly be said to consist in a headgear for use with a mask comprising a first strap configured to engage the back of a user's head and comprising a lower rear portion, a left side portion, a right side portion, and left and right side upper arch portions, the lower rear portion adapted to in use be located on a user's neck substantially below the external occipital protuberance, the left and right side portions each extending from a respective side of the lower rear portion superolaterally behind a patients ears and mastoid processes, the left and right side upper portions each comprising an arch extending over the respective ears and extending forward of a users ears to define left and right upper termination portion, a second strap extending from an apex region of the left side arch to an apex region of the right side arch, a third and fourth strap each extending from a respective side of the lower rear portion forwards and under a user ears, a fifth and sixth straps each extending forwards from a respective upper termination portion.

[0110] According to a further aspect, the fifth and sixth straps are connected to a respective side upper termination portion such that the general angular orientation of each of the fifth and sixth straps can move in a generally sagittal plane.

[0111] According to a further aspect, the generally sagittal planes correspond to the respective side surfaces of a patient's head.

[0112] According to a further aspect, the connections between the fifth and sixth straps and the respective side upper termination portion pivot about a generally laterally extending axis.

[0113] According to a further aspect, the second strap comprises a left hand side portion and a right hand side portion releasably joined together.

[0114] According to a further aspect, the second strap is adjustable in length.

[0115] According to a further aspect, the first and second straps are formed from a single flat member.

[0116] According to a further aspect, said flat member takes up a 3D headgear shape adapted to engage a user's head when the left and right hand side portions of the second strap are joined together.

[0117] According to a further aspect, the first, second, third and fourth straps are formed from a single flat member.

[0118] According to a further aspect, the third and fourth straps are not formed from said single flat member.

[0119] According to a further aspect, the fifth and sixth straps are not formed from said single flat member.

[0120] According to a further aspect, the second strap consists of a single material and the material is not soft.

[0121] According to a further aspect, the first and second straps are of a self supporting and resilient material.

[0122] According to a further aspect, the third and fourth straps are of a self supporting and resilient material.

[0123] According to a further aspect, the fifth and sixth straps are of a self supporting and resilient material.

[0124] According to a further aspect, the third and fourth straps are of a soft material.

[0125] According to a further aspect, the fifth and sixth straps are of a soft material

[0126] According to a further aspect, the left and right side arch portions consist of a single resilient material.

[0127] According to a further aspect, the width of the second, third, fourth, fifth and sixth straps is between 10mm and 30mm.

[0128] According to a further aspect, the width of the first strap except at the lower rear portion is between 10mm and 30mm.

[0129] According to a further aspect, the width of the first strap at the lower rear portion is between 10mm and 50mm.

[0130] According to a further aspect, the thickness of the first, second, third, fourth, fifth and sixth straps is between 0.1 and 3mm.

[0131] According to a further aspect, the straps are a laminate with a layer of one of the following materials:

[0132] m. Non-woven polypropylene (PP)

[0133] n. Non-woven polyethylene (PE)

[0134] o. Santoprene/polypropylene blend

[0135] According to a further aspect, the third and fourth straps include a region of reduced strap width.

[0136] According to a further aspect, the reduced width regions are adjacent the lower rear portion.

[0137] According to a further aspect, the fifth and sixth straps include a region of reduced strap width.

[0138] According to a further aspect, the reduced width regions of the fifth and sixth straps are adjacent the upper termination portions.

[0139] According to a further aspect, any one or more of the following includes a laminate structure comprising at least one soft material in addition to the:

[0140] p. the first strap,

[0141] q. the third or fourth straps,

[0142] r. the fifth or sixth straps.

[0143] In another aspect, the present invention may broadly be said to consist in an interface comprising:

[0144] a mask defining a gases cavity and having left and right sides,

[0145] headgear including left and right side straps for connection between the left side of the headgear and the left side of the mask, and between the right side of the headgear and the right side of the mask respectively, wherein

[0146] the mask includes a first separable connection for attachment to the left side strap, and a second separable connection for attachment to the right side strap, and

[0147] there being no further separable connections not located on the exterior surface of the front of the mask.

[0148] According to a further aspect, the headgear includes further left and right side straps for connection between the left side of the headgear and the left side of the mask, and between the right side of the headgear and the right side of the mask respectively, wherein

[0149] the mask further includes a third separable connection for attachment to the further left side strap, and a fourth separable connection for attachment to the further right side strap.

[0150] According to a further aspect, each separable connection comprises a protrusion located on the exterior surface of the front of the mask, and

[0151] the left and right side straps each include at least one aperture sized to fit over a respective protrusion to complete the connection.

[0152] According to a further aspect, each protrusion extends away from the mask surface and includes a flange at the distal end of the protrusion operable to resist passing through the aperture.

[0153] In another aspect, the present invention may broadly be said to consist in a mask assembly comprising a gases cavity having an interior surface, a seal for

contacting a wearer's face to substantially seal said cavity, a plenum space at least partially defined by a partition wall located within said gases space and in fluid communication with a gases entry port for receiving gases, a diffuser port outlet through which gases can flow from the plenum space to the gases cavity, and wherein the diffuser port outlet is at least partially defined by a perimeter portion of said wall.

[0154] According to a further aspect, said diffuser port extends substantially around the entire perimeter of the wall.

[0155] According to a further aspect, said diffuser port is less than 10mm wide.

[0156] According to a further aspect, said diffuser port is between 3 and 6mm wide.

[0157] According to a further aspect, the wall is configured to deflect gases flow from the entry port to enter he gases cavity around the peripheral edges of the wall proximate at least a portion of the seal.

[0158] According to a further aspect, said mask further comprises one or more pressure monitoring port.

[0159] According to a further aspect, the pressure monitoring port is located on the mask body and extends through the plenum chamber and is in fluid communication with the gases cavity.

[0160] According to a further aspect, the seal is an inflating seal.

[0161] According to a further aspect, the gases entry port has a short length of highly flexible tubing for connection to a breathing tube attached.

[0162] According to a further aspect, the total cross sectional area of the diffuser port is at least two times the area of the gases entry port.

[0163] According to a further aspect, the diffuser port extends substantially around the entire perimeter of the partition wall.

[0164] According to a further aspect, the diffuser port is not a continuous opening extending substantially around the entire perimeter of partition wall and includes regions along the partition wall periphery that are closed.

[0165] According to a further aspect, the partition wall includes one or more apertures therethrough.

[0166] According to a further aspect, the mask includes one or more flow directing rib extending approximately radially from a central region of the partition wall and projecting from the partition wall or the mask cavity wall.

[0167] In another aspect, the present invention may broadly be said to consist in a mask assembly comprising a gases cavity having an interior surface, a seal for contacting a wearer's face to substantially seal said cavity, a flow influencing structure configured to swirl breathing gases in a cyclonic pattern approximately tangential to a wearers facial surface, a gases entry port fluidly connected to the flow influencing structure.

[0168] According to a further aspect, the flow influencing structure comprises a substantially cylindrical wall extending substantially perpendicular to the mask cavity wall, a substantially conical wall extending coaxially with the cylindrical wall and defining an approximately annular swirling space between the cylindrical wall and the conical wall.

[0169] According to a further aspect, the annular swirling space is open to the cavity, and narrower near the mask cavity wall.

[0170] According to a further aspect, the gases entry port is offset from the centre of the annular swirling space and configured to direct gases flow into the annular swirling space approximately tangentially.

[0171] According to a further aspect, a mask assembly as described above further comprising an anti-asphyxiation valve.

[0172] According to a further aspect, a mask assembly as described above further comprising one or more pressure monitoring port.

[0173] In an aspect of the invention, a respiratory interface comprises an inflating soft compliant seal member adapted to cover a nose and a mouth of a user. The seal member comprises a sealing portion that is adapted to contact a face of the user. The sealing portion comprises a rolled perimetric edge and a sealing flange that extends inwardly from the perimetric edge. The sealing flange comprises an extended surface that has one end connected to the rolled perimetric edge. A support member is secured to the seal member. The support member is more rigid than the seal member. The support member comprises a support member perimetric edge. The rolled perimetric edge of the sealing portion extends outward beyond the support member perimetric edge. A generally vertical medial plane divides the interface into a right half and a left half. The interface is more flexible about the generally vertical medial plane than about any generally horizontal plane that extends through the interface.

[0174] According to a further aspect, the rolled perimetric edge of the sealing portion extends beyond the support member perimetric edge around an entire length of the support member perimetric edge.

[0175] According to a further aspect, the sealing flange extends radially inwardly from substantially all of the rolled perimetric edge of the seal member.

[0176] According to a further aspect, the seal member further comprises an enclosing portion that connects to the sealing portion proximate the rolled perimetric edge of the sealing member, the enclosing portion being secured to the support member.

[0177] According to a further aspect, the sealing portion of the seal member is substantially more flexible than the enclosing portion of the seal member.

[0178] According to a further aspect, the rolled perimetric edge of the seal member in plan view is defined by a plurality of radii Rl and the rolled perimetric edge in section comprises a thickness t and an inside radius R2, a generally horizontal plane extends through a first upper connection for headgear and a second upper connection for headgear and an upper portion of the rolled perimetric edge of the seal member is defined above the generally horizontal plane, and wherein the entire upper portion of the perimetric edge satisfies (1) 4 < (R2/t) < 7 and (2) (R1/R2) < 10.

[0179] According to a further aspect, a point of first contact is positioned along at least a portion of the sealing flange such that the sealing flange is adapted to contact the face of the user before the rolled perimetric edge.

[0180] According to a further aspect, the support member comprises a plurality of individually displaceable members that are positioned between an attachment for a headgear assembly and the seal member such that the displaceable members can transfer forces from the headgear assembly to the seal member.

[0181] In an aspect of the invention, a respiratory interface comprises an inflating soft compliant seal member adapted to cover a nose and a mouth of a user. The seal member comprises a sealing portion that is adapted to contact a face of the user. The sealing portion comprises a rolled perimetric edge and a sealing flange that extends inwardly from the perimetric edge. The sealing flange comprises an extended surface that has one end connected to the rolled perimetric edge. A support member is secured to the seal member. The support member is more rigid than the seal member. The interface

defines a chamber. An airflow inlet extends into the chamber and a flow diverter is positioned within the chamber proximate the airflow inlet. The flow diverter causing at least a portion of an airflow from the airflow inlet to be diffused radially within the interface.

[0182] According to a further aspect, the diffused airflow is directed radially over at least a portion of the sealing flange.

[0183] According to a further aspect, the airflow inlet extends into the interface at an angle between about 0° and about 70° from vertical.

[0184] According to a further aspect, the flow diverter comprises a partition wall.

[0185] According to a further aspect, the flow diverter comprises a swirling structure.

[0186] According to a further aspect, the interface is in combination with a headgear assembly that is connected to the support member of the interface.

[0187] In an aspect of the invention, a headgear assembly is used to secure a respiratory interface to a head. The headgear assembly comprises a first strap portion. The first strap portion comprises a lower rear region. The lower rear region is adapted to be located on or below an external occipital protruberance. The lower rear region extends forward and upward to a first side region and a second side region. The first side region extends superolaterally from the lower rear region. The second side region extends superolaterally from the lower rear region. Each of the first and second side regions is adapted to extend rearward of a mastoid process and over an ear. The first side region comprises a first arched portion and the second side region comprises a second arched portion. The first arched portion and the second arched portion are connected by a top strap. The top strap is adapted to extend over the head from above the ears. A first termination portion extends forward from the first arched portion and a second termination portion extends forward from the second arched portion.

[0188] According to a further aspect, the top strap is adapted to be positioned forward of a crown of the head and the lower rear region is adapted to be positioned below the crown of the head such that the crown of the head is captured between the top strap and the lower rear region.

[0189] According to a further aspect, at least a portion of the first strap portion is semi-rigid.

[0190] According to a further aspect, the top strap comprises a first portion and a second portion, the first portion and the second portion being attached to each other with a connector.

[0191] According to a further aspect, the headgear assembly includes a first inelastic connecting strap and a second inelastic connecting strap, the first inelastic connecting strap and the second inelastic connecting strap being securable to an interface.

[0192] According to a further aspect, the headgear assembly includes a first elastic connecting strap and a second elastic connecting strap, the first elastic connecting strap and the second elastic connecting strap being securable to the interface.

[0193] According to a further aspect, the first inelastic connecting strap and the first elastic connecting strap extend in parallel between the first termination portion and the interface and the second inelastic connecting strap and the second elastic connecting strap extend in parallel between the second termination portion and the interface.

[0194] According to a further aspect, the headgear assembly comprising a third inelastic connecting strap and a fourth inelastic connecting strap, the third inelastic connecting strap and the fourth inelastic connecting strap extending between the first strap portion and the interface.

[0195] According to a further aspect, the headgear assembly including a first lower connecting strap and a second lower connecting strap extending away from the first strap portion, at least a portion of the first and second lower connecting straps being semirigid whereby the first and second lower connecting straps are adapted to present laterally outward or forward when the lower rear region is positioned on the head such that the first lower connection strap and the second lower connecting strap are less likely to tangled behind the head when the headgear assembly is positioned on the head.

[0196] According to a further aspect, the first lower connecting strap and the second lower connecting strap are connected to the lower rear region and the semi-rigid portion is proximate a connection between the first lower connecting strap, the second lower connecting strap and the lower rear region.

[0197] According to a further aspect, the headgear assembly is in combination with an interface, the interface comprising a support member and a seal member, the seal member being connected to the support member, the headgear assembly being connected to the support member.

[0198] According to a further aspect, an adjustment line is provided with an upper sliding connection between the adjustment line and an upper portion of the interface. A lower sliding connection is between the adjustment line and a lower portion of the interface. A left sliding connection is between the adjustment line and a left side portion of the headgear assembly. A right sliding connection is between the adjustment line and a right side portion of the headgear assembly. The adjustment line connects the upper sliding connection, the left sliding connection, and the right sliding connection and the lower sliding connection.

[0199] According to a further aspect, an adjustment mechanism is attached to the adjustment line such that a length of the adjustment line can be altered whereby a tension in an assembly of the headgear assembly and the interface can be altered

[0200] According to a further aspect, the adjustment mechanism alters the length of the adjustment line to provide a predetermined level of tension between the interface and the headgear assembly.

[0201] According to a further aspect, the interface is connected to the headgear assembly with a tensioning component, the tensioning component cooperating with a locking element such that the tensioning component provides an elastic connection between the interface and the headgear assembly during fitting of the headgear assembly and interface while the locking element creates an inelastic connection between the interface and the headgear assembly following fitting of the headgear assembly and interface.

[0202] According to a further aspect, the tensioning component comprises a line with an adjustable length and the locking element comprises a clasp.

[0203] According to a further aspect, the support member of the interface comprises attachments for the headgear assembly.

[0204] According to a further aspect, the headgear assembly connects to the interface at a first connection point, the headgear assembly being configured such that adjusting a tension of the headgear assembly takes place at or forward of the first connection point .

[0205] According to a further aspect, fastening of the headgear assembly to the interface does not comprise a strap that creates tension by being bent back toward the headgear assembly from the first connection point.

[0206] According to a further aspect, the first connection point comprises a post and the headgear assembly comprises at least one corresponding aperture that engages with the post.

[0207] In an aspect of the invention, a method of securing an interface and headgear assembly to a head, wherein the headgear assembly is moveably and elastically connected to an upper portion of the interface, comprises placing the interface on a face using a first hand, gripping a rear portion of the headgear assembly with a second hand and raising the rear portion of the headgear assembly over the head, pulling the rear portion of the headgear assembly down over a back of the head until a top strap of the headgear assembly is seated on a top of the head, releasing the headgear assembly from the second hand and releasing the interface from the first hand such that the elastically connected headgear assembly and interface substantially remain in position without being held by the first hand or the second hand, securing an inelastic lower strap to the interface and securing an inelastic upper strap to the interface such that the interface and headgear assembly are inelastically connected.

[0208] According to a further aspect, an elastic component extends between the headgear assembly and the interface assembly to provide the elastic connection between the headgear assembly and the interface, the method further comprising orienting the interface with the elastic component between the upper portion of the interface and the headgear assembly such that the headgear assembly and the interface can be correctly oriented relative to the face.

[0209] According to a further aspect, the interface comprises a seal with an inwardly extended flange, the flange comprises a recess that is adapted to receive a chin, the method further comprising position the chin within the recess while placing the interface on the face using the first hand.

[0210] According to a further aspect, the chin is positioned within the recess prior to the interface being brought into contact with a nose.

BRIEF DESCRIPTION OF THE DRAWINGS

[0211] These and other features, aspects and advantages of the present invention will now be described with reference to the drawings of several preferred embodiments, which embodiments are intended to illustrate and not to limit the invention, and in which figures:

[0212] Figure 1 is a block diagram of a humidified positive airway pressure system as might be used in conjunction with the patient interface and/or headgear that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.

[0213] Figure 2 is a side view of an interface body that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. The illustrated body is shown fitted on a user but without headgear or a breathing tube attached.

[0214] Figure 3 is a perspective view of the interface body of Figure 2.

[0215] Figure 4 is a front perspective view of an outside of a seal member of the interface body of Figure 2.

[0216] Figure 5 is a rear perspective view of an inside of the seal member of the interface of body of Figure 2.

[0217] Figure 6 is a schematic section view of a portion of the seal member showing a rolling and inflating aspect of the seal member.

[0218] Figure 7 is a graphical depiction of properties relating to rolling of the seal member.

[0219] Figure 8 is a schematic section view of a portion of the seal member showing an additional rolling and inflating aspect of the seal member.

[0220] Figure 9 is a graphical depiction of properties relating to preloading of the seal member.

[0221] Figure 10 is a front perspective view of an outside of a supporting member of the interface body of Figure 2.

[0222] Figure 11 is a rear perspective view of the inside of the supporting member of the interface body of Figure 2.

[0223] Figure 12 is a graphical depiction of properties relating to the interaction of a support member flexibility and a seal member flexibility.

[0224] Figure 13 is a front perspective view of another interface, which generally includes a modification of the interface body of Figure 2, fitted to a user using headgear that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. The illustrated interface is shown with a breathing tube or supply conduit attached.

[0225] Figure 14 is a front perspective view of an interface that is arranged and configured in accordance with certain features, aspects and advantages of the present invention with a breathing gases entry port located on a lower portion of the interface, which entry port is adapted to be positioned in a vicinity of a chin of a user.

[0226] Figure 15 is a top view of an interface that is arranged and configured in accordance with certain features, aspects and advantages of the present invention, which interface is shown in one or more bending modes.

[0227] Figure 16 is a front perspective view of another interface that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. The interface is illustrated with headgear straps shown on only one side.

[0228] Figure 17 is a front perspective view of an interface that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. The interface is illustrated without headgear straps.

[0229] Figure 18 is a front view of a portion of an interface similar to that of Figures 16 and 17 with a supporting member that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.

[0230] Figure 19 is a front view of a portion of an interface similar to that of Figures 16 and 17 with a supporting member that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.

[0231] Figure 20 is a front view of a portion of an interface similar to that of Figures 16 and 17 with a supporting member that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.

[0232] Figure 21 is a front perspective view of an interface with a support member that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.

[0233] Figure 22 is a front perspective view of an interface, which includes the interface body of Figure 2, fitted to a user using headgear that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. The illustrated interface is shown with a breathing tube or supply conduit attached.

[0234] Figure 23 is a side view of an interface and headgear that is arranged and configured in accordance with certain features, aspects and advantages of the present invention with a breathing tube or supply conduit that is connected to the interface with an elbow connector.

[0235] Figure 24 is a rear view of an interface that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. The illustrated interface comprises a plenum space with a diffuser port.

[0236] Figure 25 is a rear perspective view of an interface that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. The illustrated interface comprises a cyclonic flow inducing configuration.

[0237] Figure 26 is a side view of an interface and headgear that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.

[0238] Figure 27 is a front perspective view of a further interface, which generally includes a modification of the interface body of Figure 2, fitted to a user using headgear that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. The illustrated interface is shown with a breathing tube or supply conduit attached.

[0239] Figure 28 is a side view of an interface and headgear that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. The illustrated headgear includes integrated elastic and inelastic straps.

[0240] Figure 29 is a side view of an interface and headgear that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. The illustrated headgear includes integrated elastics and inelastic straps and a spine.

[0241] Figure 30 is a perspective view of headgear that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.

[0242] Figure 31 is a perspective view of an interface and the headgear of Figure 30 shown being fitted to a user.

[0243] Figures 32(a)-32(d) illustrate a sequence of steps for fitting an interface and headgear that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.

[0244] Figures 33(a)-33(d) illustrate a sequence of steps for fitting an interface and headgear that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.

[0245] Figure 34 illustrates a junction of a connection strap and the first strap portion of Figure 30 with the first strap portion extending over at least a portion of the connection strap to provide strain relief and reinforcement.

[0246] Figure 35 is a graphical depiction of a relationship between pressure on skin exerted by an interface and headgear assembly and leak rate from the interface.

[0247] Figure 36 is a schematic view of a testing configuration for determining a relationship between pressure and leak rate.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Overall System

[0248] With reference to Figure 1, a humidified positive airway pressure (PAP) system 100 is shown in which a patient P, or other user, is receiving humidified and pressurized gases through a patient interface 102. The PAP system 100 can be continuous, variable or bi-level positive airway pressure or any other suitable form of respiratory therapy. In some configurations, the PAP system 100 could be or include a hospital ventilator or any other suitable form of respiratory therapy. In some applications, the interface 102 can be used with non-humidified PAP systems.

[0249] The interface 102 connects to a conduit that defines a humidified gases transportation pathway or inspiratory breathing tube 104, for example. The conduit 104 may contain heating means or a heater wire (not shown) that heats the gases or the walls of the conduit to reduce condensation of humidified gases within the conduit.

[0250] The conduit 104 connects to an outlet 106 of a humidification chamber 108. The humidification chamber 108 preferably contains a volume of water 110. The humidification chamber 108 preferably is formed from a plastics material. In some configurations, the humidification chamber has a highly heat conductive base (e.g., an aluminum base or the like) that is in direct contact with a heater plate 112 of a humidifier 114.

[0251] The humidifier 114 includes a suitable controller 116. The controller 116 can be any suitable controller or control means and can be an electronic controller. The controller 116 may comprise a microprocessor-based controller that executes computer software commands stored in associated memory.

[0252] The controller 116 receives input from sources such as, for example but without limitation, a user input 118 (e.g., dial, button and the like) through which a user of the system 100 can set, for example but without limitation, a value (e.g., a preset value, an entered value or the like) that represents a desired level of humidity and/or temperature of the gases supplied to patient P. The controller may also receive input from other sources (e.g., temperature and/or flow velocity sensors 120, 122 through a connector 124, and a heater plate temperature sensor 126).

[0253] In response to a user-set humidity and/or temperature value, which can be input with the user input 118, and the other inputs, the controller 116 determines when or to what level to energize the heater plate 112 to heat the volume of water 110 within the humidification chamber 108. As the volume of water 110 within the humidification chamber 108 is heated, water vapor begins to accumulate in the volume of the humidification chamber 108 above the surface of the water volume 110.

[0254] The water vapor passes out of the outlet 106 of the humidification chamber 108 with a flow of gases (e.g., air) provided from a gases supply blower 128 or other suitable gases supply means, which flow of gases enters the humidification chamber 108 through an inlet 130. Exhaled gases from the patient's mouth are passed directly to ambient surroundings in Figure 1 or, when the therapy is being delivered by a ventilator, the exhaled gases are returned to the ventilator via an expiratory breathing tube (not shown).

[0255] The blower 128 includes a variable pressure regulator, a variable pressure regulating means or a variable speed fan 132 that draws air or other gases through a blower inlet 134. The speed of the variable speed fan 132 is controlled by a controller 136 in response to inputs for the controller 136 and a user-set, predetermined or preset value of pressure or fan speed with a user input 138 (e.g., a dial, button or the like). In some configurations, the functions of the controller 136 could be performed by the controller 1 16.

[0256] The patient interface 102 generally comprises a mask and associated headgear. The patient interfaces described below find particular utility in hospital or other urgent care settings where patients often require artificial respiratory therapy without delay. In addition, patients in such settings often receive artificial respiratory therapy for prolonged and often uninterrupted periods of time. Accordingly, the interfaces are designed to be rapidly fitted to patients and the interfaces are designed to provide

increased comfort. Preferably, the interfaces and headgear assemblies are capable of being initially fitted in less than about 25 seconds while achieving a leak rate of less than about 20 L/min with a set delivery pressure through the interface of about 15 cm H20. In addition, as shown in Figure 35, the interfaces and headgear assemblies preferably achieve a leak rate that is less than about 15 L/min and a skin surface pressure that is less than about 22.5 mmHg with a set delivery pressure through the interface of about 15 cm H20. The skin surface pressure of 22.5 mmHg has been found to be clinically significant in reducing the likelihood of developing pressure sores over prolonged treatment periods. Leakage rates of about 15 L/min have been found to be relevant to stability of equipment used to provide the pressurized gases. In some configurations, the skin surface pressure can be less than about 18 mmHg with a leak rate of less than about 11 L/min.

[0257] With reference to Figure 36, a method of determining skin surface pressure and leak rates will be described. As shown in Figure 36, one or more sensors 150 can be positioned on the face of the test subject P. The sensor or sensors 150 can be positioned along a contact region for the interface 102. Preferably, the sensor or sensors 150 are positioned along regions that are prone to developing pressure sores during treatment (e.g., the region extending from the cheek bones, under the eyes and across the nasal bridge). The sensors 150 are adapted to sense pressure. In some configurations, the sensors 150 are pressure transducers. Preferably, the sensors 150 are pressure transducers that have an operating range between about 0 mmHg and about 100 mmHg. More preferably, the sensors 150 are pressure transducers that have an operating range between about 0 mmHg and about 50 mmHg. The sensors 150 also preferably are thin film pressure transducers. In some configurations, the sensors 150 have a thickness of about 0.5 mm or less.

[0258] With the sensors 150 positioned on the face of the test subject, the interface 102 can be applied to the face of the test subject such that the interface rests on the sensors 150. The pressure source 128 can be turned on such that pressurized gases are supplied to the test subject through the interface 102. Preferably, the gases are pressurized to about 15 cm H20 for purposes of the analysis. The interface 102 can be secured in place with tension provided by a headgear assembly 700. Preferably, the headgear assembly 700 is used to provide sufficient tension to reduce to about zero the leakage between the interface and the face of the test subject in the eye region. For purposes of the test, no bias flow holes are provided (i.e., any bias flow holes in the system are occluded) in the system such that any leakage generally occurs only between the interface and the test subject.

[0259] With the interface tensioned to the face of the test subject and with the pressure source providing gases at a pressure of about 15 cm H20, the test subject then holds their breath such that the pressurized gases leak from the seal between the interface 102 and the face of the test subject P. The leakage rate can be determined using a flow meter 152. The flow meter 152 can be integrated with the ventilator or other source of positive pressure gases or the flow meter 152 can be a separate component. Preferably, the flow meter 152 is operable in the range of about 0 L/min and about 200 L/min.

[0260] While the pressurized gases leak, the leakage rate and the pressure between the interface and the face of the test subject can be monitored. After the peak leakage rate and the peak pressure have been recorded, the tension provided by the headgear assembly 700 can be adjusted (e.g., increase) and additional sets of data can be obtained. With multiple data points, a performance envelope can be derived for the interface that reflects skin pressure and leakage rates. Multiple test subjects can be used to provide multiple readings.

Exposed Nose Mask

[0261] With reference now to Figure 2, the illustrated interface 102 comprises an interface body 200 that generally comprises a compliant seal member 202 and a supporting member 204. In Figure 2, the interface 102 is shown on a patient P without any attached headgear or breathing tube connections. As will be described, at least a portion of an outer appearance of the interface 102 preferably carries an appearance of a substantial reproduction of at least one human facial feature. In some configurations, at least a portion of the outer appearance of the interface 102 comprises a substantial reproduction of at least a human nose.

[0262] As shown in Figure 2, the illustrated interface 102 is a full face mask that covers both a nose N and a mouth of the patient P, or other user. The interface 102 can be sized according to the application. In other words, the interface 102 can be provided in a variety of sizes to accommodate use by patients or other users that can vary in age upward from as young as about two years old. The interfaces 102 can be sized based upon a measurement from chin to nasal bridge on a patient. Preferably, the size ranges that can be accommodated by each consecutive interface size will overlap between about 3 mm to about 7 mm. More preferably, the sizes will overlap about 5 mm. For

example, three interface sizes can be provided based upon a chin to nasal bridge measurement criteria: small or size 1 for those with measurements up to about 110 mm; medium or size 2 for those with measurements from about 105 mm to about 130 mm; and large or size 3 for those with measurements from about 125 mm to about 145 mm. Advantageously, the measurement ranges overlap from one size to the next such that two sizes can be used on a single patient within the overlap, which ensures that patients will not fall into a gap between sizes. Other measurement techniques also can be used.

[0263] An external surface of the interface 102 preferably is of a shape familiar to the hand, which improves operation by the person placing the interface 102 on the patient. Preferably, the shape of the illustrated interface 102 encourages grasping of the interface 102 during fitting by the healthcare provider in the chin region of the interface 102. Such a grasping location results in the hand of the healthcare provider not approaching the eye region of the patient during fitting of the interface 102, which can be more calming on the patient during fitting. In addition, the protruding reproduction of the nose clearly indicates correct placement on the patient and provides a significant visual and tactile cue for correct location, making the mask very easy and intuitive to fit and to use.

[0264] Preferably, the interface 102 has a low profile that generally conforms to the contour of the face. This minimizes patient awareness of the mask and minimizes the compressible internal volume, which makes the interface 102 particularly suitable for use on ventilation. The low profile interface 102 preferably is out of the patient's line of sight and only minimally impacts on the patient's peripheral vision. In addition, relative to the prior art, the low profile interface 102 decreases the compressible volume defined within the interface while also decreasing the volume of rebreathable C02, each of results in a more desirable interface construction and enhanced interface performance.

Compliant Seal Member

[0265] With reference now to Figures 2, 4 and 5, the compliant seal member 202 is the component of the interface 200 that contacts the face of the patient P. The seal member 202 preferably is an inflating or ballooning seal type. An inflating or ballooning seal type is a type of seal that, when in use, system pressure or air flow delivered to the interface 102 acts to urge an inwardly extending flange, skirt or other similar member onto a patient's face to form a substantial seal. Thus, an inflating or ballooning seal type is different from seal types that rely solely upon interface retention forces from headgear to push or deform a cushion against the patient's face with enough force to seal the cushion against the patient's facial features.

[0266] To provide a suitable inflating or ballooning effect, the illustrated seal member 202 comprises a perimetric edge 206 and a sealing flange 208 that extends inwardly from the perimetric edge 206. Preferably, the sealing flange 208 extends inwardly from all or substantially all of the perimetric edge 206. As will be described, the perimetric edge 206 preferably comprises a rolled edge.

[0267] With reference to Figure 5, the illustrated sealing flange 208 comprises an extended surface 210, at least a portion of which will abut a skin surface of a face of a patient P. The extended surface 210, which has one end portion that is connected to the perimetric edge 206, defines a pocket-like structure that captures air or pressure from the air supply and that urges the flange 208 of the interface body 200 toward the face of the patient P to a desired degree. The sealing flange 208 can define at least a part of a sealing portion 212 of the illustrated seal member 202. The sealing portion 212 faces the patient, or is closest to the patient, in use. With reference to Figure 6, the sealing portion 212 of the illustrated seal member 202 can be connected to an enclosing portion 214 of the seal member 202 at the perimetric edge 206, which can be defined by the rolled edge or by a radiused edge.

[0268] Preferably, the sealing portion 212 is substantially more flexible than the enclosing portion 214. The sealing portion 212 can be formed, for example but without limitation, of the same material as the enclosing portion 214 but the sealing portion 212 can have a lower thickness than the enclosing portion 214. In some embodiments, a different material, such as a silicone, a thermoplastic elastomer or a foam (e.g., open or closed including a skin) may be used for the sealing portion 212 relative to the enclosing portion 214. In use, the sealing portion 212 rests against the face of the patient P and, under an internal pressure of the inflating seal and a retention pressure of headgear, the sealing portion 212 is pressed against the face of the patient P to create an effective seal inward of the perimetric edge 206.

[0269] With reference to Figure 4, the perimetric edge 206 comprises a shape that can be defined by a series of radii ¾. The radii Rj can be defined to the outer surface of the rolled perimetric edge 206. Thus, the outermost portion of the rolled perimetric edge 206 has a plan view shape that is defined by the series of radii Ri. In addition, as shown in Figure 6, the rolled over perimetric edge 206 can be defined by a thickness (t) and an inside radius (R2). Figure 7 illustrates a desired relationship between the ratio of the inside radius of the rolling portion of the perimetric edge 206 at a particular segment to a wall thickness of the perimetric edge at that particular segment (Ri/t), hereinafter wall ratio, and the ratio of the particular radius Rj of a particular segment of the perimetric edge 206 to the inside radius of the rolling portion of the perimetric edge 206 at that particular segment of the perimetric edge (Rt/R^, hereinafter roller over ratio. As illustrated, it has been found that at a wall ratio of about 4 or less, the perimetric edge 206 of the seal member 202 may be subject to collapsing in that particular segment rather than exhibit a desired rolling. In addition, it has been found that a wall ratio of about 7 or more results in a configuration that may be too stiff in that particular segment to allow a desired rolling. Moreover, it has been found that at a radius ratio of about 10 or more, the particular segment of the seal member 202 may be too straight to allow a desired rolling. Thus, the region illustrated in Figure 7 with hatching is a region of desired reliability for the perimetric edge 206. The perimetric edge 206, because it is defined by a series of radii in plan view, may have various segments that are positioned within the region of desired rollability. Preferably, at least the upper portion of the perimetric edge 206 (i.e., the portion that would leak in the general direction of the eyes when in use) is configured such that the dimensions completely fall within the region of desired rollability. In other words, preferably those segments satisfy the following two equations: (1) 4 < (R2/f) < 7 and (2) (Ri/R2) < 10. In some configurations, at least the nasal portion of the seal member 202 and the laterally extending portions of the seal member 202 that extend toward the cheekbones are configured such that the dimensions (i.e., roll radius, plan radius and wall thickness) result in at least those segments falling within the region of desired rollability and satisfy the above-identified equations. In some configurations, at least the portion of the seal member 202 that is located above a generally horizontal plane that intersects upper headgear attachment location is configured such that the dimensions (i.e., roll radius, plan radius and wall thickness) result in at least those segments falling within the region of desired rollability and satisfy the above-identified equations. In some configurations, the entire perimeter of the seal member 202 is configured such that the dimensions (i.e., roll radius, plan radius and wall thickness) result in every segmented falling within the region of desired rollability and satisfy the above-identified equations.

[0270] Preferably, the sealing portion 212 curves inwardly to such an extent that the seal portion 212 forms an acute angle relative to the enclosing portion 214.

Moreover, with reference to Figure 8, the flange 208 is shown contacting a skin surface of the patient P. As shown, relative to a point of first contact 216, which is the end of the flange 208 disposed furthest from the perimetric edge 206 in the illustrated arrangement, the start of the radius R2 can be located at a distance 218 between about 0 mm and about 40 mm or more. As shown in the graph of Figure 9, a relationship is believed to exist between (1) the distance 218 (i.e., the distance between the point of first contact 216 and the start of the radius R2) and (2) a preload angle Θ, which is an angle between the flange 208 and the surface of the skin regardless of the location around the perimetric edge 206. The preload angle can be as shown graphically in Figure 9, which graph was generated empirically. According to this relationship, the flange 208 is able to smoothly roll and compress against the face of the patient P. As shown in Figure 9, increasing the contact length on the skin of the patient P can allow the contact angle to be lower, which indicates that a degree of protrusion of the free end of the flange can be decreased with a significant contact length. On the other hand, a greater protrusion of the free end of the flange can provide adequate sealing over a shorter contact length. In some configurations, the choice of the length 218 can be based upon the variation of a patient's facial geometry. In other words and by way of example only, to achieve a single size mask for varied populations, the flange is longer in the chin region where the dimensions of the face vary the most and the flange is shorter in the nasal region where the geometry varies less in dimension for a given ethnic group. The nasal bridge dimensions may vary from ethnic group to ethnic group. With the desired lengths determined, the angle can be determined to reduce the likelihood of leakage.

[0271] As described directly above, the point of first contact 216 results because the end of the flange 208 protrudes outward in at least some locations. In some embodiments, the free end of the flange 208 is the first surface of the interface body 200 to contact the face of the patient P. The distance 218 of the flange 208 preferably extends toward the face of the patient by between about 0 mm and about 10 mm. In some embodiments, the protrusion is between about 3 mm and 7 mm.

[0272] Advantageously, because the flange 208 presents toward the face of the patient, the free end of the flange 208, or another portion of the flange 208, after touching the face of the patient, curves inward (i.e., is bent inward) from a normal position a progressively increasing amount as the mask is urged into tighter contact with the face of the patient. Thus, the flange is preloaded while being donned, which provides the seal

with an enhanced ability to conform around various facial anatomies and contours, which in turn provides improved sealing performance for the interface body 200.

[0273] Because the illustrated seal member 202 is an inflating or ballooning seal type, the seal member 202 acts to minimize the pressure on the skin. In addition, the seal member 202 acts to distribute pressure and reduce the likelihood of excessive localized pressure distributions. In other words, the illustrated seal member 202 reduces the likelihood of point-loading or excessive pressure gradients.

[0274] With reference again to Figure 2, the seal member 202 is shown enveloping the nose N and mouth of the patient P. The seal member 202, as shown in Figures 4 and 5, comprises a nasal portion 220 that is shaped to be a substantial reproduction of the human nose. Preferably, the nasal portion 220 is an upper portion of the seal member 202. In the illustrated configuration, at least an outside surface of the nasal portion 220 is shaped to include a substantial reproduction of a human nose. Preferably, the outside surface and the inside surface of the nasal portion 220 are shaped to include a substantial reproduction of a human nose. In particular, in the illustrated configuration, the nasal portion 220 reproduces a substantial portion of a nose shape. Thus, the nasal portion 220 reproduces a majority of a nose shape.

[0275] In some embodiments, the nasal portion 220 of the seal member 202 reproduces the whole nose or very nearly the whole nose. The nose shape in the illustrated embodiment will be a generalized nose shape rather than matched to the particular patient. The illustrated nasal portion 220 comprises a nasal bridge 222. The illustrated nasal portion also may comprise nostril flares 224 or other similar features. Preferably, the nasal portion 220 simulates sufficient features to be representative of a human nose and to bear semblance to a human nose. In some embodiments, however, the seal member 202 may include a portion shaped to form a pocket or nasal chamber 226 that is capable of receiving a human nose but that does not constitute a substantial reproduction of the appearance of the nose. In other words, the seal member 202 can have a nasal portion with a shape that approximates a shape of a rectangular cuboid or that is substantially semi-cylindrical, for example but without limitation.

[0276] The nasal chamber 226 defined within the nasal portion 220 preferably is larger than a typical nose to accommodate a variety of user's noses within the interior of the nasal portion 220. Preferably, the seal member 202 comprises a septum protrusion 228. The septum protrusion 228 extends forward (i.e., away the face when worn) in the region of the septum to define an enlarged recess on the inside of the seal member 202 in the region of the nasal septum of the patient. The seal member 202 also preferably comprises an upper lip protrusion 230 that is positioned proximate the center of the upper lip. By providing one or more of the septum protrusion 228 and the upper lip protrusion 230, the nasal chamber 226 is enlarged at those locations to provide added clearance in the seal member 202.

[0277] With reference to Figure 5, the sealing portion 212 of the illustrated seal member 202 can be shaped to substantially conform to a shape of a typical face. In the illustrated configuration, the sealing portion 212, which includes the flange 208, comprises a hollow region 232. The hollow region 232 can accommodate the chin of the patient. The hollow region 232 can cup the chin along a portion of the flange 208. With continued reference to Figure 5, the illustrated sealing portion 212, which includes the flange 208, also comprises a valley 234 for the bridge of the nose. The valley 234 can comprise a curved wall that is generally C-shaped or U-shaped.

[0278] With continued reference to Figure 5, the illustrated sealing portion 212, which includes the flange 208, comprises curving cheek portions 236 that extend between the hollow region 232, which is situated proximate the chin of the patient, and the valley 234, which is situated proximate the bridge of the nose of the patient. The curving cheek portions 236 can connect proximate the hollow region 232. In addition, the valley 234 lies between and, in some configurations, separates and connects the curving cheek portions 236.

[0279] Figure 4 is a view of the exterior of the seal member 202. The exterior view better illustrates the enclosing portion 214. In the illustrated configuration, the seal member 202 incorporates cheek portions 238, a chin portion 240 and the nasal portion 220. The cheek portions 238 preferably spread laterally outward from the nasal portion 220. In use, the cheek portions 238 extend outward from the nasal region toward the zygomatic process of the patient. The cheek portions 238 also extend downward with lateral portions 239 toward the chin portion 240. Thus, the cheek portions 238 extend toward the mandible of the patient at a location outside of the lateral extremities of the mouth.

[0280] With reference again to Figures 4 and 5, the seal member 202 defines an aperture 242 that extends from the exterior surface to the interior surface of the seal member. The aperture 242 can be positioned at or lower than a location where the mouth

of the patient might be positioned during use of the interface body 200. In some embodiments, the aperture 242 is positioned below the nasal chamber 226. The aperture 242 can be described as positioned below the septum protrusion 228. The aperture 242 further can be described as positioned below the upper lip protrusion 230. Moreover, the aperture 242 can be described as positioned above the hollow region 232 that accommodates the chin of the patient. Thus, the aperture 242 can be positioned between where the mouth of the patient might be expected and the tip of the chin of the patient. The aperture 242 preferably is positioned along a medial plane of the seal member 202, which medial plane generally bisects the seal member 202 into a right half and a left half. For reasons that will be explained below, the illustrated aperture 242 lies on a generally flat plane portion 244 of the seal member.

Supporting Member

[0281] With reference again to Figure 2, the supporting member 204 overlies a portion of the seal member 202. The supporting member 204 is substantially more rigid than the compliant seal member 202 such that the supporting member 204 provides support to the compliant seal member 202. However, the supporting member 204 still can be somewhat flexible and the supporting member 204 preferably is not fully rigid. In some configurations, the supporting member 204 has a similar stiffness to an approximately 1 mm thick sheet of polypropylene or polyethylene plastic material, for example but without limitation.

[0282] As shown, the supporting member 204 comprises a perimetric edge 250. The perimetric edge 250 may have a similar shape to the perimetric edge 206 of the seal member 202 but, when a notch 252 is spanned and the spanning distance is included in the length of the perimetric edge 205, the perimetric edge 250 preferably has a shorter length compared to the perimetric edge 206 of the seal member. In other words, a total length of the perimeter of the supporting member 204 preferably is less than a total length of the perimeter of the seal member 202. Due to the inclusion of the upper portion of the nasal portion 220 in the perimeter of the seal member 202, the total length of the perimeter of the supporting member (even including the dimensions of the notch 252) is less than a total length of the perimetric edge 206 of the supporting member 204.

[0283] In some configurations, the seal member 202 extends outward beyond the supporting member 204 in all locations. As illustrated in Figure 6, the radius R2 can be defined with a spacing RO of between about 3 mm and about 6 mm defined from the

perimetric edge 250 of the supporting member 204 to an outside surface of a rolled over portion of the seal member 202.

[0284] As shown in Figures 10 and 11, the illustrated supporting member 204 comprises a contoured plate-like appearance. In other words, the supporting member 204 has form in three dimensions yet does not have a high level of relief. Preferably, the supporting member 204 has a total depth of relief of less than about 50 mm and about 65 mm in an interface sized for an average adult interface.

[0285] The otherwise generally smooth and continuous appearance of the perimetric edge 250 is interrupted by an upper notch 252. The notch 252 is positioned in the region of the nose of the patient. Thus, in the illustrated embodiment of Figure 2, the supporting member 204 does not include a portion that resembles a human nose. By not comprising the human nose portion, the supporting member 204 has an improved bulk flexibility. Instead, the shape of a human nose is defined by the seal member 202 or some other component of the interface body 200. The notch 252 improves the flexibility of the support member 204. Thus, if there are different cheek bone angles, the support member 204 will flex slightly to better fit the patient.

[0286] In the illustrated configuration, the nasal portion 220 of the seal member 202 protrudes from the upper notch 252 in the support member 204. The shape of the illustrated notch 252 in the support member 204 accommodates the shape of the nasal portion 220 the seal member 204. The notch 252, by removing a nasal portion of the support member 204, provides the support member 204 with a shape that has minimal curvature from front to back (i.e., the support member 204 has a low profile and small depth of relief when formed).

[0287] In overall impression, the illustrated configuration provides a full face interface that resembles the human form while functioning to assist in controlling the ballooning of the seal member 202 by supporting the enclosing portion 214 of the seal member 202. The external appearance of the interface in use is of being partially human, thereby improving the emotional response of patients and of people observing the patient using the interface. Importantly, this may improve acceptance of the interface by patients and thereby improve compliance.

[0288] The notch 252 preferably defines a recess that extends inward from the perimetric edge 250 of the supporting member 204. In the illustrated configuration, the notch 252 extends inward toward a center of the interface body 200 or at least a center of the supporting member 204. The notch 252 may include an extended notch portion 251 to accommodate the septum. Other suitable profiles also can be provided to the notch 252 as desired. In some configurations, the notch 252 may be positioned above a ridge 253 that defines a valley on the inside of the support member 204 to further accommodate the central portion of the upper lip.

[0289] In the illustrated supporting member 204, the notch 252 is flanked by a pair of upward extensions 254 that are separated by the notch 252. Preferably, the upward extensions 254 define an uppermost extent of the support member 204. More preferably, the upward extensions 254 define an uppermost portion of the interface body 200 with the exception of portions of the very flexible seal member 202.

[0290] With reference to Figure 2, the nose N of a patient P is illustrated in broken lines. The nose N protrudes into the chamber 226 defined by the nasal portion 220 of the seal member 202 while the notch 252 of the support member 204 crosses the medial plane at a location below the nose N. The upward extensions 254 of the support member 204 extend upwardly beyond a base B of the nose. In the illustrated configuration, the upward extensions 254 extend upward beyond a portion of the interface body 200 that is designed to accommodate a tip of the nose N of the patient P.

[0291] The lateral side edges of the notch 252 extend alongside lateral margins of the nose N such that the compliant seal member 202 can extend along the cheekbones and such that the support member 204 can reinforce the seal member 202 in the cheekbone region. Support of the interface body 200 on the cheekbones of the patient P can significantly improve the comfort level experienced by the patient P.

[0292] The upward extensions 254 also provide a stabilizing function and define, at least in part, means for stabilizing the illustrated mask on a central portion of the face of the patient. In particular, the upward extensions 254 roughly correspond to or overlap with a location of the maxilla bones of the skull.

[0293] The support member 204 generally conforms to a typical lower portion of a human face. As such and with reference to Figures 10 and 1 1, an outer surface 256 of the support member 204 has a generally convex appearance while an inner surface 258 of the support member 204 has a generally concave appearance. The inner surface 258 of the support member 204 generally conforms to an outside surface of the seal member 202. A chin portion 260 of the support member 204 can comprise a hollow concavity along the inner surface 258 of the support member 204. In addition, each of a pair of cheek

portions 262 comprises a hollow concavity along the inner surface 258 of the support member.

[0294] The perimetric edge 250 of the support member 204 generally extends outside of the cheek portions 262 to outside of the chin portion 260 and generally follows inside a jaw line of the patient. As such, the illustrated perimetric edge 250 of the support member 204 extends to a chin of the patient P. Preferably, a lower portion 264 of the support member 204 hooks under the chin of the patient P. By hooking under the chin of the patient P, the support member 204 assists the seal member 202 in sealing in this region of the face of the patient P. The illustrated support member 204 defines an expanse of material that backs the seal member 202 and reinforces the chamber defined by the enclosing portion 214 of the seal member 202. In some configurations, the support member 204 defines a reinforcing rim that generally encircles a portion of the seal member 202.

[0295] As illustrated in Figures 2 and 3, the interface body 200 generally reproduces the general shape of the lower half of the user's face. The interface body 200 can cover the nose at the upper end. In some configurations, the interface body 200 is adapted to overlap with at least a portion of the nasal bone, which is the bone that extends above the cartilage of the nose and that is positioned between the eyes. At least the seal member 202 can include wings that extend outward toward the zygomatic bone of the wearer such that the seal member 202 extends outwards to follow the cheekbones. The interface body 200 extends downward to follow the jaw line to where the lower portion 264 of the support member 204 hooks under the chin.

[0296] With continued reference to Figures 10 and 11, the supporting member 204 also comprises a generally centralized opening 266. The opening 266 is positioned generally below the notch 252. Preferably, the opening 266 is positioned along the medial plane of the interface body 200, which is the plane that divides the illustrated interface body 200 into substantially symmetrical bilateral left and right halves. In the illustrated configuration, the opening 266 and the notch 252 both are positioned along the medial plane. The medial plane intersects, and preferably bisects, the opening 266 and the notch 252.

[0297] The opening 266 in the supporting member 204 preferably corresponds in location to the aperture 242 that is defined through the seal member 202. The aperture 242 is shown more clearly in Figures 4 and 5. The aperture 242 provides a location for a breathing gases inlet and outlet to the chamber that is defined on the face side of the seal member 202. By being positioned on the flat plane portion 244, the aperture 242 facilitates convenient connection and sealing of a supply breathing tube to the seal member 202. The support member 204 in the region of the opening 266 also may be configured to support the connection of the supply breathing tube (e.g., an elbow connector or other configuration of connector).

Bridge Section

[0298] With reference to Figure 13, some embodiments of the supporting member 204 may also include a bridge section 300 that extends at least over the seal member 202 in the region of the notch 252. Thus, in some embodiments, the bridge section 300 may be positioned near the perimetric edge 206 of the seal member 202 in the region of the nasal portion 220. The bridge section 300 may provide additional support for the inflating seal member 202 in this region. The additional support can be useful in reducing the likelihood of air leaks along the sides of the nose, which air leaks may direct air in the general vicinity of the eyes of the patient.

[0299] With reference to Figure 14, the bridge section 300 in this embodiment extends over the seal member 202 near the perimetric edge 206 of the seal member 202. The bridge section 300 shown in Figure 14 preferably is between about 5 mm and 6 mm wide. The embodiment of Figure 14 provides increased flexibility to the support member 204 and the seal member 202, which provides greater conformability to a wearer's facial geometry. In other words, the supporting member 204 has a lower flexible stiffness, which allows the interface 200 to flex under a retention force provided by headgear straps while the bridge portion 300 provides support for the seal member 202 in or proximate to the nasal portion 220. The bridge portion helps to reduce the likelihood of deflection of the seal member 202 at the bridge of the nose, which deflection can result in air leaks that are directed toward the general vicinity of the eyes.

[0300] With continued reference to Figure 14, a load 302 applied in a lateral direction while the opposite side of the mask is held stationary causes flexing of the interface 200 about the medial plane. In the illustrated embodiment, the flexing reduces the overall width of the interface 200. The force 302 is applied at a location near the cheek portion 262 of the interface 200. Preferably, the force 302, when having a magnitude of about IN, will result in at least about 4 mm or more preferably at least about 5 mm of displacement when measured generally parallel to the direction of the force 302.

While headgear generally does not apply the force 302 in the direction of the arrow, it has been found that the described flexing can be found in the interface 200. It also has been found that the flexing can help achieve an improved seal of the sealing member 202 over a wide range of facial geometries.

[0301] Preferably, the flexing or bending is about the medial plane. In some embodiments, it is preferable that the interface 200 is more flexible or deformable in the cheekbone region of the interface 200 (i.e., in an upper portion) compared to the jawbone region of the interface 200 (i.e., a lower portion). Such a difference in flexure zones can be achieved by the notch 252. Thus, the notch 252 can be used to provide an interface that is more deformable in the cheekbone region where greater anatomical variation may be expected and where the face is more sensitive to discomfort.

[0302] With reference now to Figure 15, the interface 200 is capable of flexing up to approximately 20 degrees under typically encountered forces from headgear when in use. For example, Figure 15 illustrates the interface 200, which comprises the seal member 202 and the supporting member 204. The supporting member 204 preferably is sufficiently flexible to deform substantially about the medial plane M. The interface 200 that is shown in Figure 15 from a top down view also is shown in perspective view in Figure 14 and in side view in Figure 23. As illustrated, the illustrated interface 200 comprises a generally triangular appearance from the top down view of Figure 15. In addition, a recess 306 is formed along a base 308 of the triangle in this view. Of course, the recess 306 is configured in accommodate at least a portion of the nose of the patient. In the side view of Figure 23, the interface 200 comprises a generally square or truncated pyramid shape. In some configurations, no significant recess can be identified along the interface when viewed from the side. The illustrated configuration results in an interface that is significantly more flexible about the generally vertical medial plane when compared to the flexibility about a generally horizontally extending plane. Moreover, the illustrated configuration results in an interface that is longer from top to bottom than wide from the outermost cheek portion to the outermost cheek portion and that has an upper perimeter surface 310 that is generally triangular (i.e., the upper portion of the perimetric surface that extends between the cheek portions is generally triangular when viewed from the front) and a lower perimeter surface 312 that is generally triangular (i.e., the lower portion of the perimetric surface that extends between the cheek portions is generally triangular when view from the front). The upper perimeter surface being generally

triangular and the lower perimeter surface being generally triangular along with the nasal portion and the chin portion being recessed relative to the cheek portions provide a configuration that is significantly more flexible about the vertical medial plane when compared to the flexibility about a horizontally extending plane.

[0303] As illustrated in Figure 15, the left hand side of the interface 200 is braced to reduce the likelihood of movement and a force 304 is applied. Preferably, the force 304 is applied at approximately the widest point of the interface 200, which generally corresponds to the cheekbone portions. With the force 304 applied, the interface 200 preferably deforms such that angle a changes to angle β (i.e., the change in angle is α - β). In one embodiment, the change from a to β is at least about 10 degrees when the force 304 is applied at a 3N magnitude. In a more particular embodiment, strap forces typical of an interface in use are believed to be capable of causing a deformation of approximately α - β = 10° to 50°. In a further embodiment, α - β is at least approximately 10° to 30 ° under typical strap forces of about 1.5 N to about 15 N per strap assuming four straps are used.

[0304] In one embodiment, the force 304 with a IN magnitude is capable of deforming the interface 200 at least about 5 mm. In a further embodiment, the force 304 with a 3N magnitude is capable of deforming the interface 200 between about 5 mm and about 50 mm. In another further embodiment, the force 304 of 3N magnitude is capable of deforming the interface 200 between about 15 mm and about 25 mm.

[0305] In use, the deflection of the supporting member 204 may occur to close or open the shape of the interface. In some embodiments, the force applied to open the interface 200 a given amount may be less than the force applied to close the interface 200 by the same amount. For example, in one embodiment, a force applied in a direction opposite of force 304 (i.e., an opening force) of IN magnitude is capable of deforming the interface 200 at least about 3 mm. In a further embodiment, an opening force of 3N magnitude is capable of deforming the interface 200 between about 3 mm and about 25 mm. In another further embodiment, an opening load of 3N magnitude is capable of deforming the interface between about 10 mm and about 20 mm.

[0306] With reference to Figure 12, a flex modulus of the supporting member 204 and a flex modulus of the seal member 202 can be interrelated. As shown in the graphical illustration of Figure 12, the flex modulus of the material that forms the seal member 202 preferably is less than about 15 MPa. At levels that significantly exceed

about 15 MPa, the seal member 202 has been found to be too stiff or rigid. On the other hand, the flex modulus of the support member 204 preferably is less than about 480 MPa. At levels that significantly exceed about 480 MPa, the support member 204 has been found to be too stiff or rigid. In addition, the flex modulus of the support member 204 preferably is above about 50 MPa. At levels significantly less than about 50 MPa, the support member 204 exhibits excessive flexure. Finally, in defining flexure characteristics that are desired in both the support member 204 and the seal member 202, it has been found that a desired interrelationship can be found within the hatched envelop shown in Figure 12.

Flexible Interface Support

[0307] Historically, an ability of an interface to seal on a face of a patient has been hindered by difficulties in conforming to the facial geometry of the patient. The result of the inability to accurately conform the interface to the particular facial geometry of the patient is excessive leaking between the interface seal and the patient's face. With prior interface configurations, tightening of headgear can result in a force vector on the interface that unevenly loads the seal contact surface on the face of the patient. Uneven loading of the seal contact surface can result in pressure points in some locations and in inadequate pressure in other locations. The pressure points may result in irritation of the skin of the patient while the locations of inadequate pressure are likely to lead to leakage.

[0308] With reference to Figures 16-21, several embodiments of interfaces 200 are illustrated that present structures that enhance the ability of the interfaces 200 to conform to and seal with the face of the patient more evenly. The structures also enhance the ability of the interfaces 200 to conform to a wide variety of face geometries. Preferably, more even distribution of seal pressure can be achieved by applying a composite construction to the interfaces 200. Thus, the interfaces 200 can flex and contort to accommodate different facial geometries while allowing the sealing member 202 to inflate or balloon between the support member 204 and the face, thereby more evenly distributing the headgear fitting force onto the interface between the sealing member and the skin.

[0309] As shown in Figure 16, the patient interface 200 comprises the soft compliant seal member 202 and the support member 204, such as those described above. The seal member 202 is adapted in use to cover a nose and a mouth and to seal around a face along the perimetric edge 206 of the seal member 202. For the most part, the

interface 200 shown in Figure 16 is the same as the interface 200 shown in and described with respect to Figure 2. In particular, the features of Figures 16-21 described below can be implemented with the interfaces 200 that are arranged and configured in accordance with the descriptions contained elsewhere in this application, for example.

[0310] An added support member 404 is provided over the seal member 202 or the support member 204 in order to provide support to the seal member 202. The support member 404 and the seal member 202 have a small wall thickness and are formed to be complimentary in shape such that the seal member 202 fits snugly underneath the support member 404. Preferably, in at least one embodiment, the outer profile or shape of the support member 404 and the seal member 202 substantially follow the contour of a typical face such that the interface 200 comprises a relatively low profile component. In some embodiments, the patient interface 200 may be more typical in size and dimensions.

[0311] The support member 404 comprises a central hub portion 470 that is connected to the support member 404. In some configurations, the central hub portion 470 can be directly connected to the seal member 202. Radiating outwards from the hub portion 470 are a plurality of displaceable members 472 or 'fingers' that are separated at the ends by spaces 490. The displaceable members 472 preferably are cantilevered from the hub portion 470 and extend outwards towards the perimetric edge 206. The displaceable members 472 preferably are not rigidly bonded or attached to the underlying seal member 202 so that relative sliding motion can occur between the seal member 202, or the support member 204 when present, and the displaceable members 472.

[0312] In some embodiments, the displaceable members 472 may be resiliently hinged rather than cantilevered. In such a configuration, the displaceable members 472 are moveable with respect to one another substantially in a front to back direction (with respect to a face when wearing the interface 200) such that a force applied by headgear acting on the hub portion 470 urges the interface 200 towards the face.

[0313] Preferably, the displaceable members 472 are made of a material that is significantly stiffer than the soft compliant seal member 202. For example, any typical polymer materials used in interface frames may be appropriate, such as polypropylene, polyethylene or polycarbonate, for example but without limitation. According to one variation, the displaceable members 472 may include elastic material extending between adjacent lateral margins of adjacent fingers 472 in a manner similar to a catcher's mitt. In other words, webbing of an elastic material may extend between adjacent fingers 472.

[0314] The plurality of displaceable members 472 function to distribute a load applied to the central hub 470 across the wider surface area of the interface 200 thereby providing a more localized force to press the perimetric edge 206 of the seal member 202 onto a user's face. In particular, because the displaceable fingers 472 are cantilevered from the hub 470 and because the displaceable fingers 472 provide significant front to back movement at the free ends, the support member 404, which includes the displaceable members 472, can conform to a face and can providing an adequate seal for a wide variation of facial geometries. The sliding movement of at least free ends 474 of the displaceable members 470 with respect to the underlying seal member 202 provides a mechanism by which the members 472 can put pressure on slightly different parts of the underlying seal member 202 depending upon the differing geometry of a user's face. Such a construction can increase the conformability of a given seal to a wide range of facial geometries.

[0315] If a wearer has a relatively flat face, it is easier to achieve a good seal. However, if a user has a face that includes large front to back variations in shape, the free ends 474 of the displaceable members 472 provide localized pressing forces at locations distant from the relatively central hub 470 such that the forces from the headgear can be transmitted from the hub 470 to the free ends 474.

[0316] In some configurations, multiple hub portions 470 may be located non-centrally on the interface with each hub portion 470 having displaceable members 472 extending therefrom. For example, the chin and left and right cheeks are preferable places to load a user's face and the interface may include hub portions 470 at one or more of these locations.

[0317] With reference now to Figure 18, a further support member 480 can be applied to the support member 404 shown in Figures 16 and 17. In some configurations, the support member 480 can be secured to the support member 404 to form a laminate-type structure. The support member 480 can comprise a plurality of displaceable members 482 that are moveable with respect to each other and/or at least an inner hub portion 484 of the further support member 480. Preferably, the fingers 482 of the further support member 480 bear on the fingers 472 of the support member 404. While the illustrated configuration shows the same number of displaceable members on the support member 404 and the additional support member 480, the number and placement of the displaceable members can vary. In some embodiments, the plurality of displaceable

members associated with the further support member 480 may bear directly on the seal member 402.

[0318] It will be appreciated that embodiments may be constructed where combinations will be present. In other words, some of the plurality of fingers (either of the support member or of the further support member) may bear directly on the seal or may bear on other fingers. For example the interface 200 illustrated in Figure 16 includes the support member 204 interposed between the seal member 402 and the support member 404 (and/or further support member (not shown)). In this embodiment, the free ends 474 of the support member (and/or further support member) bear on the support member 204, which in turn applies pressure to the underlying seal member 402. The support member 204 serves to further spread the loading forces across the seal member 402 and/or support the softer seal member 402.

[0319] In an alternative embodiment shown in Figure 19, the free ends 474 of the support member (and/or further support member) can bear directly on the compliant seal member 202 beneath. In the embodiment shown in Figure 20, the free ends 474 of the fingers bear on the underlying displaceable members 482 of the further support member. Any other suitable variations also can be used.

[0320] The above description gives only a few examples of interface seal types where displaceable members can provide improved facial fit and/or improved sealing. Other configurations also are possible. The number, spacing and width of the displaceable members can be varied. In addition, while the example embodiments illustrated in Figures 16-21 all show support members (and further support members) that are generally circular in plan view, and/or illustrate displaceable members that radiate generally from a central location, other shapes are possible. For example, rather than a central generally circular hub, a linear or generally rectangular hub may be employed. In such an embodiment, the displaceable members 474 may radiate outwards in a 'leaf like' structure or like the branches of a tree as shown in Figure 21, for example but without limitation. In such an embodiment, it may be preferable that the hub is substantially aligned with a mid sagittal plane of a user when wearing the interface. In addition, the hub may include one or more a semi-rigid reinforcing ribs 492 to substantially stiffen the "trunk" of the structure. The inclusion of the trunk reinforcing rib 492 provides a beam to resist bending in a given direction.

[0321] In a further alternative embodiment the displaceable members may be constructed having a variable thickness in order to tailor the stiffness of the cantilevered sections with respect to bending the front to back direction. For example, the material thickness of the fingers may decrease towards the free ends. Similarly, the fingers may or may not have a substantially rectangular plan profile as illustrated in the figures. For example, the width of the displaceable members may narrow towards the free ends or may have differing shapes to provide a desired level of displacement.

[0322] In a further alternative embodiment, the free ends of the displaceable members described in the above embodiments may further include features where the free end bears on the sealing member or on an underlying further support member. For example, a compressible material pad may be located between the free end and the seal surface such that the compressible pad bears on the seal member. In another example, the free end may be rounded at the point of contact between the free end and the seal member. Alternatively, the free end may include a compliant member that bears on the seal. The compliant member may be foam or a plurality of small compressible hoop structures for example.

[0323] The forgoing describes example of the interface support that can be applied in combination with the reproduced nose interface described earlier. The interface support can be used with other interface configurations having a soft compliant seal. For example, it is not necessary to have a support body in between the seal and the displaceable support members. In at least one embodiment, this configuration is preferable. In other words, the displaceable support members may act directly on the compliant seal at specific locations to press the interface seal against a users face. Similarly, the interface support is not limited in application to any single head gear configuration. The general purpose of the interface support is to distribute the force applied by the headgear to substantially a single location over a wide area and, as such, the disclosed configurations can define means for distributing a localized force over an interface body. In particular, the interface support can distribute the force over a wide area and/or also accommodate a large variation in facial contours in the front to back direction.

Breathing Tube Connections

[0324] With reference now to Figures 14 and 22 a breathing tube 500 is shown connected to the interface 200 in at least two different manners. The connections that will be described between the breathing tube and the interface can be interchanged. In addition, any of the described connections can be used with any of the described interfaces.

[0325] With reference initially to Figure 22, the illustrated breathing tube 500 is connected to a breathing tube connector with an elbow 504. The breathing tube connector can be fitted to and sealed with the aperture 242 of the seal member 202. Because the breathing tube connector is secured to the aperture 242, the breathing tube connector extends through the opening 266 formed in the support member 204.

[0326] In some configurations, a snap fit arrangement is provided wherein a semi-rigid section of the connector protrudes through the aperture 242 in the seal member 202 from one side of the seal member 202 while another semi rigid section of the connector can be snap fit to the first semi-rigid member. In some configurations, any other suitable technique for bonding may be used to form a boss on the soft compliant seal member 202 and the connector can be connected to the boss. The elbow 504 can be connected to the connector.

[0327] In Figure 22, the interface body 200 is shown with the breathing tube 500 is connected to the connector with the elbow 504, which connector may be connected to the seal member 202 or to seal member 202 and the support 204. A swivel 502 allows the elbow 504 to rotate relative to the interface body 200 so the supply conduit 500 can take up different orientations with respect to the interface body 200, thereby improving user comfort during movement, for example but without limitation. A further swivel 506 may be provided between the elbow 504 and the breathing tube 500.

[0328] The interfaces described herein also can be used with a bi-directional flow ventilator with the conduit 500 being short and being connected to a Y-piece. In addition, with a uni-directional flow system provided, for example, by a CPAP machine, appropriate ventilation holes may be provided in the elbow 504 or in a region near the bridge of the nose of the seal member 202. Moreover, rather than the swivel 502, a ball-joint type connection can be provided to allow articulation between the breathing tube 500 and the interface body 200.

[0329] In some configurations, such as that illustrated in Figure 14, the interface body 200 may include an anti-asphyxiation valve 520. The anti-asphyxiation valve 520 may be associated with the interface body or, in some embodiments, may be

incorporated into the breathing conduit connection or into the elbow connector, for example but without limitation.

[0330] While suitable for use, the connection using the elbow 504 results in the breathing gases entering the interface body 200 substantially horizontally. Accordingly, the breathing gases are directed straight towards the patient's mouth. It has been found that this arrangement has several disadvantages. For example, patients may feel uncomfortable having breathing gases directed straight at their face or mouth. Additionally, the elbow connector 504 is attached to the front of the interface body 200 and projects outwardly away from the user's face a distance. The top of the interface body 200 (i.e., the nasal portion 220 of the interface body 200), where the seal member 202 interacts with the nose, is a portion that is difficult to seal due to considerable anatomical variations among patients. As a result, the bridge of the nose is a common site for interface leakage. Any torque applied the interface body 200 may aggravate the sealing problem in this region. In order to compensate for this effect, it is common to overtighten the headgear to push the interface body 200 tightly onto a patient's face. The overtightening can lead to discomfort, which is highly undesirable.

[0331] With continued reference to Figure 14, in this embodiment, connection to the breathing tube 500 can be made with a short flexible tube 522 that connects directly to the breathing tube and that enters the interface body 200 in the vicinity of the wear's chin and at an angle (projecting downwards from a wearer's chin). Thus, the gases enter the interface in a direction that is upwards and towards a patient's mouth and nose. In other words, the tube 522 extends downwards and away from the patient.

[0332] The flexible tube 522 connects to the interface body through a port 525. The port 525 is located below a line extending directly outwards through a patient's mouth when facing forward in a normal position. Preferably, the conduit 522 enters the interface body 200 through the port 525 at an angle between about 0° and about 70° from vertical. In some configurations, the entry angle is between about 50° and about 60°. Preferably, the entry angle is about 55°.

[0333] Preferably the gases port 525 is located in the vicinity of the patient's chin (i.e., between the patient's lower lip and the tip of the chin,). This port location advantageously positions the port 525 such that the front of the interface body 200 has more room for attachment mechanisms, such as holes, posts, loops, clips and the like. In addition, this port location also provides more room for the anti-asphyxiation valve 520 to be located forward of the mouth. Moreover, the location of the breathing gases entry port 525 in the vicinity of the lowest point of the interface interior when in use provides an effective vomit drain.

[0334] The short length of tubing 522 allows natural head movement of the patient by being very flexible and making the location of the connection between the patient interface 200 and breathing tube 500 distant from the interface itself. The connection between patient interface 200 and breathing tube 500 can be achieved via rigid connectors of a known type. Positioning these connectors away from the chin and neck of a patient improves the patient's head mobility, especially when tilting the head forwards.

[0335] Any other suitable technique of supplying pressurized gases to the interface body also can be used.

Interface Flow Control

[0336] With reference now to Figures 24 and 25, diffusion and control of flow within the interface body 200 will be described. The interface body 200 can be configured in any suitable manner and, in the illustrated configuration, the interface body 200 comprises a cavity 600 defined within the interface 200 by the seal member 202, for example but without limitation. The seal member 202 can be configured in any suitable manner, including but not limited to those disclosed within this application. In use, the seal member 202 contacts and seals against the face of the patient. When sealed against the face, the seal member 202 reduces the likelihood of air or gases leaking out of the cavity 600.

[0337] The breathing tube or another short flexible tube 104 connects to the interface body 200 in any suitable manner, including but not limited to those described within this application. The breathing tube 104 supplies breathing gases to an entry port 602. The entry port 602 preferably is located in a region of the interface body 200 that will be located within the vicinity of the chin of the patient. More preferably, the entry port 602 is configured such that the breathing gases are introduced in an upwardly inclined direction rather than directly toward the face of the patient.

[0338] With reference to Figure 24, the cavity 600 defined within the seal member 202 can be segmented by a partition wall 604. The partition wall 604 can be formed within the cavity 600 in any suitable manner. The partition wall 604 preferably is mounted or supported within the cavity 600 by a boss 606 or other suitable mounting structure. In such a configuration, the partition wall 604 is mounted at a location

contained within a boundary defined by a peripheral edge 608 of the partition wall 604. In the illustrated configuration, the entire peripheral edge 608 is spaced from the inner wall of the seal member 202 or other interface wall defining the cavity 600.

[0339] The partition wall 604 can be offset from the inner wall such that a gap is defined between the partition wall 604 and the inner wall. The partition wall 604 preferably approximately follows the general shape of the cavity 600 such that a plenum space is defined by an approximately constant gap between the partition wall 604 and the inner wall. Preferably, the gap between the partition wall 604 and the inner surface of the cavity 600 is less than about 10 millimeters. More preferably, the gap is between about 3 millimeters and about 6 millimeters. In some configurations, an incident angle between the flow from the port 602 and the partition wall is between about 30° and about 80°. In some configurations, the incident angle is between about 50° and 70°. Preferably, the incident angle is about 60°.

[0340] A diffuser port or a diffuser outlet 610 can be defined by a space between the peripheral edge 608 of the partition wall 604 and the inner wall. In some configurations, the partition wall is generally circular and has a diameter of between about 30 mm and about 100 mm. In configurations, the diameter is between about 40 mm and 80 mm. The peripheral edge 608 of the partition wall preferably is sized and positioned to extend near to the outer perimeter of the seal member 202. More preferably, the peripheral edge 608 of the partition wall 604 extends into a region that is overlapped by the extended surface 210 defined by the flange 208.

[0341] The partition wall 604 also preferably is contained within the lower portion of the cavity 600. More preferably, an upper margin 612 of the partition wall 604 is positioned at or below the cheekbone level of the interface body 200. Even more preferably, the upper margin 612 of the partition wall 604 is generally aligned with a lowermost portion of the notch 252 for the nasal portion 220. Accordingly, the upper margin 612 can be positioned generally at the same position as the nose of the patient.

[0342] In the illustrated embodiment, the diffuser outlet 610 is substantially or completely contiguous about the entire partition wall 604. In some configurations, the diffuser outlet 610 can be defined solely along the upper margin 612 of the partition wall 604. In some configurations, the diffuser outlet 610 includes the region along the upper margin 612 such that the diffuser outlet 610 includes an upper diffuser port portion that causes breathing gases to flow substantially tangentially over the wearer's cheek bone region.

[0343] In some configurations, however, the partition wall 604 does not follow the contour of the inner surface of the seal member 202 and, therefore, the gap defined between the partition wall 604 and the inner surface of the seal member 202 is not substantially constant.

[0344] The entry port 602 provides gases from the breathing tube into the plenum space that is defined within the cavity 600. The entry port 602 leads into the plenum chamber that is defined between the partition wall 604 and the inner surface of seal member 202 or, where the seal member 202 is replaced by the support member 204 in a particular region of the interface body 200, the inner surface of the support member 204. Thus, the gases provided through the entry port 602 generally are prevented from flowing directly to a patient's mouth by the partition wall 604. Rather, the gases stream impacts the partition wall 604 and is deflected throughout the thin plenum chamber.

[0345] Where the inner wall that defines the cavity 600 and the partition wall 604 approximate the contours of the wearers face, the resulting diffused breathing gases flow is substantially tangential to the facial surface. The diffused breathing gases flow exits the plenum chamber through the diffuser port 610, which is defined by the gap between the inner cavity wall and the periphery 608 of the partition wall 604.

[0346] The plenum chamber functions as a means to evenly distribute breathing gases flow to the patient around the edges of the partition wall without substantially increasing resistance to flow. In interfaces that incorporate an inflating or ballooning seal, the diffuser port 610 that directs the flow radially outward from the entry port 602 instead of having the flow continue along the axis of the entry port 602 directs the flow toward and preferably onto the perimeter of the seal member 202, which helps seal the flange 208 to the face of the patient.

[0347] In some configurations, the partition wall 604 can be supported in a number of different locations (e.g., at least two or more locations). The partition wall 604 could be supported in such a manner that the diffuser port 610 includes distinct regions along the peripheral edge 608 of the partition wall 604 and/or along the upper margin 612 that are not a continuous open port. In other words, the diffuser port 610 may not be a continuous opening extending substantially around the entire perimeter 608 of the partition wall 604.

[0348] Preferably, the total cross sectional area of the diffuser port(s) 610 is greater than the cross sectional area of breathing gases entry port 602. With such a construction, the gases velocity decreases from the entry port 602 to the diffuser port 610. Preferably, the cross sectional area of the diffuser port 610 is at least twice the cross sectional area of the entry port 602. Even more preferably, the cross sectional area of the diffuser port 610 is between 2 and 5 times the cross sectional area of the entry port 602. The enlarging of the cross sectional area reduces the occurrence of ventilation synchrony issues and jetting effects on the patients. For example, the spreading and/or slowing of the gases flow, together with the tangential redirection of the gases flow over the wearer's skin, results in a more comfortable patient experience.

WHAT IS CLAIMED IS

1. A respiratory interface comprising an inflating soft compliant seal member adapted to cover a nose and a mouth of a user, the seal member comprising a sealing portion that is adapted to contact a face of the user, the sealing portion comprising a rolled perimetric edge and a sealing flange that extends inwardly from the perimetric edge, the sealing flange comprising an extended surface that has one end connected to the rolled perimetric edge, a support member secured to the seal member, the support member being more rigid than the seal member, the support member comprising a support member perimetric edge, the rolled perimetric edge of the sealing portion extending outward beyond the support member perimetric edge and a generally vertical medial plane dividing the interface into a right half and a left half, the interface being more flexible about the generally vertical medial plane than about any generally horizontal plane that extends through the interface.

2. The interface of Claim 1, wherein the rolled perimetric edge of the sealing portion extends beyond the support member perimetric edge around an entire length of the support member perimetric edge.

3. The interface of any of Claims 1 and 2, wherein the sealing flange extends radially inwardly from substantially all of the rolled perimetric edge of the seal member.

4. The interface of any of Claims 1-3, wherein the seal member further comprises an enclosing portion that connects to the sealing portion proximate the rolled perimetric edge of the sealing member, the enclosing portion being secured to the support member.

5. The interface of Claim 4, wherein the sealing portion of the seal member is substantially more flexible than the enclosing portion of the seal member.

6. The interface of any of Claims 1-5, wherein the rolled perimetric edge of the seal member in plan view is defined by a plurality of radii R\ and the rolled perimetric edge in section comprises a thickness t and an inside radius R2, a generally horizontal plane extends through a first upper connection for headgear and a second upper connection for headgear and an upper portion of the rolled perimetric edge of the seal member is defined above the generally horizontal plane, and wherein the entire upper portion of the perimetric edge satisfies (1) 4 < (R2/t) < 7 and (2) (¾/¾) < 10.

7. The interface of any of Claims 1-6, wherein a point of first contact is positioned along at least a portion of the sealing flange such that the sealing flange is adapted to contact the face of the user before the rolled perimetric edge.

8. The interface of any of Claims 1-7, wherein the support member comprises a plurality of individually displaceable members that are positioned between an attachment for a headgear assembly and the seal member such that the displaceable members can transfer forces from the headgear assembly to the seal member.

9. A respiratory interface comprising an inflating soft compliant seal member adapted to cover a nose and a mouth of a user, the seal member comprising a sealing portion that is adapted to contact a face of the user, the sealing portion comprising a rolled perimetric edge and a sealing flange that extends inwardly from the perimetric edge, the sealing flange comprising an extended surface that has one end connected to the rolled perimetric edge, a support member secured to the seal member, the support member being more rigid than the seal member, the interface defining a chamber, an airflow inlet extending into the chamber and a flow diverter positioned within the chamber proximate the airflow inlet, the flow diverter causing at least a portion of an airflow from the airflow inlet to be diffused radially within the interface.

10. The interface of Claim 9, wherein the diffused airflow is directed radially over at least a portion of the sealing flange.

11. The interface of any of Claim 9 and Claim 10, wherein the airflow inlet extends into the interface at an angle between about 0° and about 70° from vertical.

12. The interface of any of Claim 9-11, wherein the flow diverter comprises a partition wall.

13. The interface of any of Claim 9-11, wherein the flow diverter comprises a swirling structure.

14. The interface of any of Claims 1-13 in combination with a headgear assembly that is connected to the support member of the interface.

15. A headgear assembly used to secure a respiratory interface to a head, the headgear assembly comprising a first strap portion, the first strap portion comprising a lower rear region, the lower rear region being adapted to be located on or below an external occipital protraberance, the lower rear region extending forward and upward to a first side region and a second side region, the first side region extending superolaterally from the lower rear region, the second side region extending superolaterally from the

lower rear region, each of the first and second side regions being adapted to extend rearward of a mastoid process and over an ear, the first side region comprising a first arched portion and the second side region comprising a second arched portion, the first arched portion and the second arched portion being connected by a top strap, the top strap being adapted to extend over the head from above the ears, a first termination portion extending forward from the first arched portion and a second termination portion extending forward from the second arched portion.

16. The headgear assembly of Claim 15, wherein the top strap is adapted to be positioned forward of a crown of the head and the lower rear region is adapted to be positioned below the crown of the head such that the crown of the head is captured between the top strap and the lower rear region.

17. The headgear assembly of Claim 15 or 16, wherein at least a portion of the first strap portion is semi-rigid.

18. The headgear assembly of any of Claims 15-17, wherein the top strap comprises a first portion and a second portion, the first portion and the second portion being attached to each other with a connector.

19. The headgear assembly of any of Claims 15-17 further comprising a first inelastic connecting strap and a second inelastic connecting strap, the first inelastic connecting strap and the second inelastic connecting strap being securable to an interface.

20. The headgear assembly of Claim 19 further comprising a first elastic connecting strap and a second elastic connecting strap, the first elastic connecting strap and the second elastic connecting strap being securable to the interface.

21. The headgear assembly of Claim 20, wherein the first inelastic connecting strap and the first elastic connecting strap extend in parallel between the first termination portion and the interface and the second inelastic connecting strap and the second elastic connecting strap extend in parallel between the second termination portion and the interface.

22. The headgear assembly of any of Claims 19-21 further comprising a third inelastic connecting strap and a fourth inelastic connecting strap, the third inelastic connecting strap and the fourth inelastic connecting strap extending between the first strap portion and the interface.

23. The headgear assembly of any of Claims 15-17 further comprising a first lower connecting strap and a second lower connecting strap extending away from the first strap portion, at least a portion of the first and second lower connecting straps being semirigid whereby the first and second lower connecting straps are adapted to present laterally outward or forward when the lower rear region is positioned on the head such that the first lower connection strap and the second lower connecting strap are less likely to tangled behind the head when the headgear assembly is positioned on the head.

24. The headgear assembly of Claim 23, wherein the first lower connecting strap and the second lower connecting strap are connected to the lower rear region and the semi-rigid portion is proximate a connection between the first lower connecting strap, the second lower connecting strap and the lower rear region.

25. The headgear assembly of any of Claims 15-24 in combination with an interface, the interface comprising a support member and a seal member, the seal member being connected to the support member, the headgear assembly being connected to the support member.

26. The headgear assembly and interface of Claim 14 or 25 further comprising an adjustment line, an upper sliding connection between the adjustment line and an upper portion of the interface, a lower sliding connection between the adjustment line and a lower portion of the interface, a left sliding connection between the adjustment line and a left side portion of the headgear assembly, a right sliding connection between the adjustment line and a right side portion of the headgear assembly, the adjustment line connecting the upper sliding connection, the left sliding connection, and the right sliding connection and the lower sliding connection.

27. The headgear assembly and interface of Claim 26 further comprising an adjustment mechanism attached to the adjustment line such that a length of the adjustment line can be altered whereby a tension in an assembly of the headgear assembly and the interface can be altered

28. The headgear assembly and interface of Claim 27, wherein the adjustment mechanism alters the length of the adjustment line to provide a predetermined level of tension between the interface and the headgear assembly.

29. The headgear assembly and interface of Claim 14 or 25, wherein the interface is connected to the headgear assembly with a tensioning component, the tensioning component cooperating with a locking element such that the tensioning component provides an elastic connection between the interface and the headgear assembly during fitting of the headgear assembly and interface while the locking element creates an inelastic connection between the interface and the headgear assembly following fitting of the headgear assembly and interface.

30. The headgear assembly and interface of Claim 29, wherein the tensioning component comprises a line with an adjustable length and the locking element comprises a clasp.

31. The headgear assembly and interface of Claim 14 or 25, wherein the support member of the interface comprises attachments for the headgear assembly.

32. The headgear assembly and interface of Claim 14 or 25, wherein the headgear assembly connects to the interface at a first connection point, the headgear assembly being configured such that adjusting a tension of the headgear assembly takes place at or forward of the first connection point .

33. The headgear assembly and interface of Claim 32, wherein fastening of the headgear assembly to the interface does not comprise a strap that creates tension by being bent back toward the headgear assembly from the first connection point.

34. The headgear assembly and interface of any of Claim 32 and Claim 33, wherein the first connection point comprises a post and the headgear assembly comprises at least one corresponding aperture that engages with the post.

35. A method of securing an interface and headgear assembly to a head, the headgear assembly being moveably and elastically connected to an upper portion of the interface, the method comprising placing the interface on a face using a first hand, gripping a rear portion of the headgear assembly with a second hand and raising the rear portion of the headgear assembly over the head, pulling the rear portion of the headgear assembly down over a back of the head until a top strap of the headgear assembly is seated on a top of the head, releasing the headgear assembly from the second hand and releasing the interface from the first hand such that the elastically connected headgear assembly and interface substantially remain in position without being held by the first hand or the second hand, securing an inelastic lower strap to the interface and securing an inelastic upper strap to the interface such that the interface and headgear assembly are inelastically connected.

36. The method of Claim 35, wherein an elastic component extends between the headgear assembly and the interface assembly to provide the elastic connection between the headgear assembly and the interface, the method further comprising orienting the interface with the elastic component between the upper portion of the interface and the headgear assembly such that the headgear assembly and the interface can be correctly oriented relative to the face.

37. The method of any of Claim 35 and Claim 36, wherein the interface comprises a seal with an inwardly extended flange, the flange comprises a recess that is adapted to receive a chin, the method further comprising position the chin within the recess while placing the interface on the face using the first hand.

38. The method of Claim 37, wherein the chin is positioned within the recess prior to the interface being brought into contact with a nose.