H EADGEAR ASSEM BL I ES AND I NTERFACE ASSEM BL I ES WI TH H EADGEAR

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

[0001] Any and all applications for which a foreign or domestic priority claim is made in connection with the present application are hereby incorporated by reference and made a part of the disclosure.

BACKGROUND

Field

[0002] The present disclosure relates to headgear and interface assemblies for use in respiratoiy therapy. More particularly, the present disclosure relates to a substantially inelastic three dimensional headgear, portions thereof and a process for moulding such headgear. Further applications of the moulding process are also disclosed.

Description of Related Art

[0003] The treatment of respiratory ailments or conditions with therapies, such as NIV, Bi-level or CPAP, involves the delivery of pressurized air to the airways of a human via a conduit and a breathing apparatus (e.g., a mask or cannula). Typically, a mask creates at least a substantial "seal" on or around the nose and/or the mouth of a user while a cannula does not provide a seal but provides a delivery pathway for supplemental respiratoiy gas delivery.

[0004] A result of creating this "seal" is that the combination of the enclosure area of the breathing apparatus and its internal pressure creates a resulting force that attempts to push the breathing apparatus off of the face. To counteract this force, it is normal to use a headgear comprising a series of straps that pass around the back and/or top of a user's head. Headgear such as this are typically made from a compliant material, such as Breath-o-prene™. The use of such a material results in the headgear having relatively little structure when not being worn. This lack of structure can give rise to the straps of the headgear

becoming tangled, which in turn can make it difficult for a user to don the headgear and breathing apparatus.

[0005] The strap(s) require some form of adjustment to account for variation in head size, this adjustment mechanism is typically provided via an adjustment loop between the mask body and the head gear. The adjustment loop can have a hook-and-loop or similar fastener that permits an end of the strap to be passed through a mounting location on the mask or through a clip that attaches to the mask and then attached to another section of the strap. Such an arrangement permits adjustment of the headgear by positioning the end of the strap at a desired location on the other section of the strap to vary a size of the adjustment loop.

[0006] These types of mechanism are one solution to providing an adjustment mechanism for the headgear and, thus, the interface assembly. Such systems also require a reasonable level of user interaction and, as a result, is prone to misuse or mis-adjustment (e.g., over-tightening). As a practical matter, micro-adjustment of such systems is difficult and time-consuming to accomplish. The creation of practical and not so practical solutions to this has been the subject of considerable development effort from a number of organisations, which has resulted in numerous patents.

[0007] Further, these traditional headgear are usually configured to have some elasticity. This can result in the headgear stretching over, and applying pinching forces to, the user's head, which can be uncomfortable. It is desirable to make headgear and breathing apparatus that are easy to use and comfortable to wear because this may improve a user's compliance with the therapy being provided.

SUMMARY

[0008] The systems, methods and devices described herein have innovative aspects, no single one of which is indispensable or solely responsible for their desirable attributes. Without limiting the scope of the claims, some of the advantageous features will now be summarized.

[0009] A headgear system and/or an interface assembly incorporating a headgear system that upon fitment to the head of a user automatically adjusts to the correct size and, once in use, transforms in properties from an elasticated "stretchy" strap/strapping to an "inelastic" strap/strapping.

[0010] In some configurations, a headgear assembly for supporting a respiratory interface on a user comprises a rear headgear portion configured to contact the rearward and/or upper portions of a head of the user. The rear headgear portion comprises a plastic core and a textile casing. The plastic core and the textile casing are formed as an integral structure by the application of a molten plastic material into the textile casing. Each side of the rear headgear portion comprises a mounting portion configured to be located forwardly of an ear of the user in use. An interface connection arrangement is provided to the mounting portion on each side of the headgear assembly. Each interface connection arrangement is configured to be directly or indirectly coupled to the respiratory interface. Each interface connection arrangement includes at least one length adjusting arrangement. Each length adjusting arrangement comprises an elastic element, a core member and a restriction arrangement. The core member is associated with the elastic element and is fixed relative to one end of the elastic element. The core member passes through the restriction arrangement. The restriction arrangement is configured to selectively engage the core member to resist movement of the core member relative to the restriction arrangement.

[0011] In some configurations, the rear headgear portion has no structure passing below the ear of the user that would inhibit removal of the rear headgear portion in an upward direction.

[0012] In some configurations, each of the interface connection arrangements comprises at least a first length adjusting arrangement and a second length adjusting arrangement.

[0013] In some configurations, a location of at least one of the first length adjusting arrangement and the second length adjusting arrangement on the mounting portion is adjustable.

[0014] In some configurations, each of the mounting portions comprises a plurality of mounting locations for the first length adjusting arrangement and the second length adjusting arrangement, wherein the mounting locations are unitarily formed with the plastic core.

[0015] In some configurations, at least one connector is configured to connect the interface connection arrangements to the respiratory interface.

[0016] In some configurations, the at least one connector comprises at least one collection passage configured to receive a portion of the core members.

[0017] In some configurations, the restriction arrangements are located on the rear headgear portion.

[0018] In some configurations, the rear headgear portion defines at least one collection passage configured to receive a portion of the core members.

[0019] In some configurations, the at least one collection passage is defined by the plastic core or between the plastic core and the textile casing.

[0020] In some configurations, the restriction arrangements are located remotely from an end of the elastic element.

[0021] In some configurations, a guide for a portion of the core member is provided between the end of the elastic element and the restriction arrangement.

[0022] In some configurations, the elastic element comprises an inelastic portion that restricts the elastic element to a maximum length.

[0023] In some configurations, a headgear assembly for supporting a respiratory interface on a user comprises a rear headgear portion configured to contact the rearward and/or upper portions of a head of the user. The rear headgear portion comprises a plastic core and a textile casing. The plastic core and the textile casing are formed as an integral structure by the application of a molten plastic material into the textile casing. An interface connection arrangement is provided to each side of the headgear assembly. Each interface connection arrangement is configured to be directly or indirectly coupled to the respiratory interface. Each interface connection arrangement includes at least one length adjusting arrangement. Each length adjusting arrangement comprises an elastic element, a core member and a restriction arrangement. The core member is associated with the elastic element and is fixed relative to one end of the elastic element. The core member passes through the restriction arrangement. The restriction arrangement is configured to selectively engage the core member to resist movement of the core member relative to the restriction arrangement. The at least one restriction arrangement is located on the rear headgear portion. [0024] In some configurations, the rear headgear portion has no structure passing below the ear of the user that would inliibit removal of the rear headgear portion in an upward direction.

[0025] In some configurations, the rear headgear portion defines at least one collection passage configured to receive a portion of the core members.

[0026] In some configurations, the at least one collection passage is defined by the plastic core or between the plastic core and the textile casing.

[0027] In some configurations, the restriction arrangement is located remotely from the other end of the elastic element.

[0028] In some configurations, a guide for a portion of the core member is provided between the end of the elastic element and the restriction arrangement.

[0029] In some configurations, the elastic element comprises an inelastic portion that restricts the elastic element to a maximum length.

[0030] A headgear system and/or an interface assembly incorporating a headgear system that upon fitment to the head of a user automatically adjusts to the correct size and, once in use, transforms in properties from an elasticated "stretchy" strap/strapping to an "inelastic" strap/strapping.

[0031] In some configurations, a headgear assembly for supporting a respiratory interface on a user includes a substantially inelastic rear portion, a substantially inelastic front portion, a first elastic side portion on a first side of the headgear assembly, and a second elastic side portion of a second side of the headgear assembly. At least one filament extends through or along the first and second elastic side portions. The at least one filament coupled to one of the inelastic rear portion and the inelastic front portion, and at least one restriction arrangement. The at least one filament passes through the at least one restriction arrangement. The aL least one restriction arrangement is configured to selectively engage the at least one filament to resist movement of the at least one filament relative to the at least one restriction arrangement.

[0032] In some configurations, the at least one restriction arrangement is configured to provide a first resistance force to movement or attempted movement of the at

least one filament in a direction that allows the inelastic rear portion and the inelastic front portion to move away from one another.

[0033] In some configurations, the at least one restriction arrangement is configured to provide a second resistance force to movement or attempted movement of the at least one filament in a direction that allows the inelastic rear portion and the inelastic front portion to move toward one another, wherein the second resistance force is less than the first resistance force.

[0034] In some configurations, the inelastic front portion is rigid.

[0035] In some configurations, the inelastic front portion is configured to be connected to a respiratory interface.

[0036] In some configurations, the inelastic front portion defines at least one collection passage that accommodates a portion of the at least one filament.

[0037] In some configurations, each of the first and second elastic side portions comprises an end cap having an opening through which the at least one filament passes. The end cap can be overmolded onto the respective one of the first and second elastic side portions. The end cap can be coupled to the inelastic front portion.

[0038] In some configurations, the inelastic rear portion, the inelastic front portion, the first elastic side portion and the second elastic side portion define a closed loop perimeter.

[0039] In some configurations, the at least one filament comprises a first filament associated with the first elastic side portion and a second filament associated with the second elastic side portion. The at least one restriction arrangement can comprise a first restriction arrangement associated with the first elastic side portion and a second restriction arrangement associated with the second elastic side portion.

[0040] In some configurations, the at least one collection passage comprises a first collection passage that accommodates a portion of the first filament and a second collection passage that accommodates a portion of the second filament.

[0041] In some configurations, the restriction arrangement comprises a pair of lockjaws that define a space therebetween through which the filament passes. The lockjaws

have a first relative position engaging the filament to provide the first resistance force and a second relative position that provides the second resistance force.

[0042] In some configurations, the interface includes a forehead support and the at least one collection passage is located on the forehead support.

[0043] In some configurations, the headgear comprises upper and lower elastic side portions on each side, upper and lower filaments and upper and lower restriction arrangements. In some such configurations, the there is an upper collection passage and lower collection passage. These upper and lower collection passages on each side of the headgear can be separate from one another.

[0044] In some configurations, inelastic front portion defines an opening configured to receive a portion of the respiratoiy interface, wherein the at least one collection passage comprises a first collection passage and a second collection passage, wherein at least a portion of the first collection passage is located above the opening and at least a portion of the second collection passage is located below the opening.

[0045] In some configurations, the inelastic front portion is configured to connect to a plurality of different interfaces.

[0046] In some configurations, the inelastic front portion comprises separate portions on each side of the headgear assembly.

[0047] In some configurations, a headgear assembly for supporting a respiratory interface on a user defines a perimeter that surrounds a head of the user. The headgear assembly can include a first portion having a fixed length along the perimeter and a second portion having a fixed length along the perimeter. At least one elastic portion has a variable length along the perimeter, wherein the at least one elastic portion has a first length and a second length that is greater than the first length. At least one filament is secured to one of the first portion and the second portion and extends through the at least one elastic portion and into at least one collection passage of the other of the first portion and the second portion. The at least one filament has a filament length that is greater than the second length of the at least one elastic portion. At least one restriction arrangement is configured to selectively engage the at least one filament to resist movement of the at least one filament relative to the at least one restriction arrangement. The at least one restriction an-angement is located at an entrance to the at least one collection passage.

[0048] In some configurations, the first portion is a front portion of the headgear assembly.

[0049] In some configurations, the second portion is a rear portion of the headgear assembly.

[0050] In some configurations, the first portion defines the at least one collection passage.

[0051] In some configurations, the at least one elastic portion is restricted to a maximum length.

[0052] In some configurations, the at least one elastic portion comprises an inelastic element that defines the maximum length.

[0053] In some configurations, the at least one elastic portion comprises a first elastic portion and a second elastic portion, wherein each of the first elastic portion and the second elastic portion extend between the first portion and the second portion.

[0054] In some configurations, the at least one filament comprises a first filament associated with the first elastic portion and a second filament associated with the second elastic portion. The at least one restriction arrangement comprises a first restriction arrangement associated with the first elastic side portion and a second restriction arrangement associated with the second elastic side portion.

[0055] In some configurations, the at least one collection passage comprises a first collection passage that accommodates a portion of the first filament and a second collection passage that accommodates a portion of the second filament.

[0056] In some configurations, the restriction arrangement comprises a pair of lockjaws that define a space therebetween through which the filament passes. The lock jaws have a first relative position engaging the filament to provide a first level of resistance and a second relative position that provides a second level or resistance that is lower that the first level.

[0057] In some configurations, a directional lock includes a housing defining an interior space, a first opening and a second opening. Each of the first and second openings communicates with the interior space. At least one lock element is pivotally coupled to the housing for rotation about a fixed pivot axis. The lock element has an aperture configured to receive a core element. The lock element is movable between a first position, in which the aperture is aligned with the first opening and the second opening, and a second position, in which the aperture is not aligned with the first opening and the second opening.

[0058] In some configurations, the lock element is a lock washer.

[0059] In some configurations, at least one of the first opening and the second opening is elongate in a direction perpendicular to the pivot axis such that the at least one of the first opening and the second opening can accommodate a core element that passes through the aperture of the at least one lock element in both the first position and the second position.

[0060] In some configurations, the at least one lock element comprises a first lock element and a second lock element.

[0061] In some configurations, the housing comprises and internal wall positioned between the first lock element and the second lock element.

[0062] In some configurations, a headgear assembly for supporting a respiratory interface on a user includes a rear headgear portion configured to contact the rearward and/or upper portions of a head of the user. Each side of the rear headgear portion comprises a mounting portion configured to be located forwardly of an ear of the user in use. The rear headgear portion has no structure passing below the ear of the user that would inhibit removal of the rear headgear portion in an upward direction. An interface connection arrangement is provided to the mounting portion on each side of the headgear assembly. Each interface connection arrangement is configured to be directly or indirectly coupled to the respiratory interface. Each interface connection arrangement comprises at least one length adjusting arrangement. Each length adjusting arrangement comprises an clastic element, a core member and a restriction arrangement. The core member is associated with the elastic element and is fixed relative to one end of the elastic element. The core member passes through the restriction arrangement. The restriction arrangement is configured to selectively engage the core member to resist movement of the core member relative to the restriction arrangement.

[0063] In some configurations, each of the interface connection arrangements comprises at least a first length adjusting an-angement and a second length adjusting arrangement.

[0064] In some configurations, the first length adjusting an-angement and the second length adjusting arrangement are spaced apart from one another on the mounting portion.

[0065] In some configurations, a location of at least one of the first length adjusting anangement and the second length adjusting anangement on the mounting portion is adjustable.

[0066] In some configurations, at least one connector is configured to connect the interface connection anangements to the respiratory interface.

[0067] In some configurations, the at least one connector comprises at least one collection passage configured to receive a portion of the core members.

[0068] In some configurations, a single connector is configured to connect both of the interface connection arrangements to the respiratory interface.

[0069] In some configurations, the connector defines an opening configured to receive a portion of the respiratory interface, wherein the at least one collection passage comprises a first collection passage and a second collection passage, wherein at least a portion of the first collection passage is located above the opening and at least a portion of the second collection passage is located below the opening.

[0070] In some configurations, the connector is configured to connect to a plurality of different interfaces.

[0071] In some configurations, the at least one connector comprises a connector on each side of the headgear assembly.

[0072] In some configurations, the restriction anangement comprises a pair of lock jaws that define a space therebetween through which the core member passes. The lock jaws have a first relative position engaging the core member to provide a first level of resistance and a second relative position that provides a second level or resistance that is lower that the first level.

[0073] In some configurations, a headgear assembly for supporting a respiratory interface on a user comprises at least one inelastic portion and at least one elastic portion having a first end and a second end. At least one filament extends through or along the at least one elastic portion. The first end of the at least one elastic portion is fixed relative to the at least one inelastic portion and the at least one filament. The second end of the at least one elastic portion is movable relative to the at least one inelastic portion and the at least one filament. The headgear assembly also comprises at least one restriction arrangement. The at least one filament passes through the at least one restriction arrangement. The at least one restriction aiTangement is configured to selectively engage the at least one filament to resist movement of the at least one filament relative to the at least one restriction arrangement. The at least one restriction arrangement is located remotely from each of the first end and the second end of the at least one elastic portion.

[0074] In some configurations, the inelastic portion is a rear headgear portion configured to contact a rearward and/or upper portion of the user's head in use, wherein the at least one restriction arrangement is located on the rear headgear portion.

[0075] In some configurations, the rear headgear portion comprises a top strap and the at least one restriction aiTangement is located on the top strap.

[0076] In some configurations, the headgear assembly is configured such that the at least one restriction arrangement is located on the top of the user's head in use.

[0077] In some configurations, the rear headgear portion comprises a rear strap and the at least one restriction arrangement is located on the rear strap.

[0078] In some configurations, the headgear assembly is configured such that the at least one restriction arrangement is located behind the user's ear in use.

[0079] In some configurations, a guide for the at least one filament is provided between the restriction arrangement and one of the first and second ends of the at least one elastic portion.

[0080] In some configurations, the restriction arrangement comprises a pair of lockjaws that define a space therebetween through which the filament passes. The lockjaws have a first relative position engaging the filament to provide a first level of resistance and a second relative position that provides a second level or resistance that is lower that the first level.

[0081] In some configurations, a patient interface system comprises a body portion sized and shaped to surround the nose and/or mouth of a user and adapted to create at least a substantial seal with the user's face. A coupling permits the patient interface to be coupled to a gas delivery system. A headgear system allows the body portion to be positioned and retained on an users head, with the head-gear system providing the ability to transform from an elastic type elongation behaviour to a non-elongating type behaviour when the interface system is in use.

[0082] In some configurations, the transformational locking behaviour is provided by a group of directional locking features.

[0083] In some configurations, the transformational locking behaviour is provided by a group of directional locking features which are located on retention planes.

[0084] In some configurations, the transformational locking behaviour is provided by a group of directional locking features which enable independent relative movement to each other.

[0085] In some configurations, the transformational locking behaviour is provided by a group of directional locking features which have dependent movement to each other.

[0086] In some configurations, the interface system contains a combination of independent and dependent movement.

[0087] In some configurations, the transformational locking behaviour is provided by a directional locking feature/s which are located on the mask body.

[0088] In some configurations, the transformational locking behaviour is provided by a directional locking feature/s which are located on or within the headgear system.

[0089] In some configurations, a combination of directional locking feature/s located on the mask body and located on or within the headgear system are used.

[0090] In some configurations, the directional lock is positioned in a location that is proximal with the connection point to the headgear.

[0091] In some configurations, the directional lock is positioned in a location that is distal with the connection point to the headgear.

[0092] In some configurations, the directional lock module incorporates a mechanism which enables user attachment/detachment between it and the mask body.

[0093] In some configurations, the directional lock module incorporates a mechanism which enables user attachment/detachment between it and the remainder of the headgear system.

[0094] In some configurations, the non-stretch behaviour of the headgear system is such that there is less than 4mm of mask movement when the patient interface system is subjected to variable pressure waveform.

[0095] In some configurations, a patient interface system comprises a body portion sized and shaped to provide a cannulated gas delivery system into the nasal passages. A coupling permits the patient interface to be coupled to a gas delivery system. A headgear system allows the body portion to be positioned and retained on an users head, with the headgear system providing the ability to transform from an elastic type elongation behaviour to a non-elongating type behaviour when the interface system is in use.

[0096] In some configurations, a patient interface system includes a body portion sized and shaped to surround the nose and/or mouth of a user and adapted to create at least a substantial seal with the user's face. A coupling permits the patient interface to be coupled to a gas delivery system. A headgear system allows the body portion to be positioned and retained on an users head, with the head-gear system providing the ability to transform from an elastic type elongation behaviour to a non-elongating type behaviour when the interface system is in use.

[0097] In some configurations, the positional stability of the headgear system is achieved via two principal portions, one that passes on or below the occipital protruberance, the other passing over the top of the head in loosely the position of the crown of the head. The relative position of these two is maintained by the material of the headgear being shape sustaining.

[0098] In some configurations, the positional stability of the headgear system is achieved via two principal portions, one that passes on or below the occipital protuberance, the other passing over the top of the head in loosely the position of the crown of the head. The relative position of these two is maintained by the gusset or connecting member/s.

[0099] In some configurations, the non-stretch behaviour of the body portion of the headgear is achieved through constructing it from a single inelastic material and variable cross sectional geometry.

[0100] In some configurations, the non-stretch behaviour of the body portion of the headgear is achieved through constructing it from a single thermoplastic material and variable cross sectional geometry.

[0101] In some configurations, the non-stretch behaviour of the body portion of the headgear is achieved through constructing it from a single thermoset material and variable cross sectional geometry.

[0102] In some configurations, the non-stretch behaviour of the body portion of the headgear is achieved through constructing it from multiple thermoplastic materials.

[0103] In some configurations, the non-stretch behaviour of the body portion of the headgear is achieved through constructing it from multiple thermoset materials.

[0104] In some configurations, the non-stretch behaviour of the body portion of the headgear is achieved through constructing it from multiple thermoplastic materials & variable cross sectional geometry.

[0105] In some configurations, the non-stretch behaviour of the body portion of the headgear is achieved through constructing it from thermoplastic material/s and an incorporated lining or padding.

[0106] hi some configurations, the non-stretch behaviour of the body portion of the headgear is achieved through constructing it from thermoset material/s and an incorporated lining or padding.

[0107] In some configurations, a headgear assembly for a respiratory interface includes a rear headgear portion, an interface coupling portion, and a length adjusting portion that adjusts a length of the headgear assembly or a perimeter length of the interface assembly when coupled to a respiratory interface. The headgear assembly exhibits an elastic force tending to contract the headgear length or the perimeter length and a non-elastic lock force tending to inhibit elongation of the headgear length or the perimeter length.

[0108] In some configurations, the headgear assembly comprises at least one retention plane.

[0109] In some configurations, the headgear assembly comprises two retention planes.

[0110] In some configurations, the retention planes converge in a direction moving from rearward to forward.

[0111] In some configurations, the retention planes converge in a direction moving from forward to rearward.

[0112] In some configurations, one of the retention planes is angled relative to the other retention plane.

[0113] In some configurations, the retention planes are separated from one another at the interface attachment locations.

[0114] In some configurations, the retention planes are generally parallel with one another.

[0115] In some configurations, the retention planes are generally horizontal.

[0116] In some configurations, the headgear assembly further comprises a manually-adjustable length adjusting portion

[0117] In some configurations, the interface coupling portion can be connected to a plurality of types of interfaces.

[0118] In some configurations, the length adjusting portion comprises at least a first portion and a second portion.

[0119] In some configurations, the first portion and the second portion are on opposite sides of the headgear assembly.

[0120] In some configurations, the interface coupling portion extends between the first portion and the second portion.

[0121] In some configurations, the first portion and the second portion are on the same side of the headgear assembly.

[0122] In some configurations, the interface coupling portion extends between the first portion and the second portion.

[0123] In some configurations, at least one core member forms a portion of the headgear length or perimeter length and can be locked relative to another portion of the headgear assembly or interface assembly to inhibit elongation of the headgear length or perimeter length.

[0124] In some configurations, a length of the core member is greater than a maximum extended length of the length adjusting portion.

[0125] In some configurations, a length of the rear headgear portion is greater than or equal to a length of the core member.

[0126] In some configurations, a length of the rear headgear portion is greater than or equal to a length of the core member.

[0127] In some configurations, at least one core collector accommodates an excess portion of the core that, at any particular headgear length or perimeter length, does not form a portion of the headgear length or perimeter length.

[0128] In some configurations, a length of the core member is less than a combined length of the core collector and a maximum extended length of the length adjusting portion.

[0129] In some configurations, a length of the rear headgear portion and a length of the core collector is fixed, and adjustment of a length of the length adjusting member provides substantially all of a length adjustment of the headgear length or the perimeter length.

[0130] In some configurations, a nasal cannula system comprises a nasal cannula and a headgear. At least one adjustment arrangement allows adjustment of a perimeter length of the nasal cannula system. The at least one adjustment arrangement includes a core member coupled to one of the headgear and the nasal cannula and a lock coupled to the other of the headgear and the nasal cannula. The lock can engage the core member to retain the nasal cannula system in a desired adjusted perimeter length.

[0131] In some configurations, the lock can retain the desired adjusted perimeter length in response to normal or expected forces in use, such as the weight of the nasal cannula and hose pull forces, for example.

[0132] In some configurations, the lock allows slippage of the core member at forces above a threshold such that the perimeter length can be increased beyond the desired adjusted perimeter length.

[0133] In some configurations, the lock is a directional lock and allows movement of the core member in a direction that reduces the perimeter length at a relatively low force, which is lower than the normal or expected forces in use.

[0134] In some configurations, the directional lock is of any structure or arrangement disclosed herein.

[0135] In some configurations, at least one biasing element applies a force to the nasal cannula system tending to reduce the perimeter length.

[0136] In some configurations, the biasing element allows the nasal cannula system to be self-fitting or automatically adjustable.

[0137] In some configurations, the nasal cannula system comprises at least one quick release arrangement that allows the perimeter loop to be quickly and easily broken, such as for removal or application of the nasal cannula system from or to a user.

[0138] In some configurations, the headgear is a single strap or a bifurcated strap arrangement.

[0139] In some configurations, the nasal cannula comprises a body having a rigid frame portion and a softer user-contacting portion.

[0140] In some configurations, an excess portion of the at least one core member that is not actively defining a portion of the perimeter length is accommodated in either the nasal cannula or the headgear. In some such configurations, the excess portion is internal to the nasal cannula or the headgear. In some such configurations, the excess portion is accommodated in a circular accumulator.

[0141] In some configurations, multiple adjustment arrangements are provided. In some such configurations, an adjustment arrangement is provided on each side of the nasal cannula system. In some such configurations, the excess portions of the core members of each side are positioned above and below one another on or within the nasal cannula.

[0142] In some configurations, a nasal cannula system comprises a nasal cannula and a headgear. At least one adjustment arrangement allows adjustment of a perimeter length of the nasal cannula system. The at least one adjustment arrangement includes a core member coupled to one portion of the headgear and a lock coupled to another portion of the headgear that is movable relative to the first portion. The lock can engage the core member to retain the nasal cannula system in a desired adjusted perimeter length.

[0143] In some configurations, the lock can retain the desired adjusted perimeter length in response to normal or expected forces in use, such as the weight of the nasal cannula and hose pull forces, for example.

[0144] In some configurations, the lock allows slippage of the core member at forces above a thi'eshold such that the perimeter length can be increased beyond the desired adjusted perimeter length.

[0145] In some configurations, the lock is a directional lock and allows movement of the core member in a direction that reduces the perimeter length at a relatively low force, which is lower than the normal or expected forces in use.

[0146] In some configurations, the directional lock is of any structure or arrangement disclosed herein.

[0147] In some configurations, at least one biasing element applies a force to the nasal cannula system tending to reduce the perimeter length.

[0148] In some configurations, the biasing element allows the nasal cannula system to be self-fitting or automatically adjustable.

[0149] In some configurations, the nasal cannula system comprises at least one quick release arrangement that allows the perimeter loop to be quickly and easily broken, such as for removal or application of the nasal cannula system from or to a user.

[0150] In some configurations, the headgear is a single strap or a bifurcated strap arrangement.

[0151] In some configurations, the nasal cannula comprises a body having a rigid frame portion and a softer user-contacting portion.

[0152] In some configurations, an excess portion of the at least one core member that is not actively defining a portion of the perimeter length is accommodated in the headgear. In some such configurations, the excess portion is internal to the headgear. In some such configurations, the excess portion is accommodated in a circular accumulator.

[0153] In some configurations, multiple adjustment arrangements are provided. In some such configurations, an adjustment arrangement is provided on each side of the nasal cannula system.

[0154] In some configurations, a directional lock includes a lock member having an aperture or opening and is configured to engage a core member or filament that passes through the opening. The opening can change cross-sectional dimensions between one side of the lock member and the other side of the lock member and/or the profile of the opening can be tapered.

[0155] In some configurations, the side of the opening that defines a working edge of the lock member that engages the core member in a locked position is smaller than the opposite side of the opening.

[0156] In some configurations, the profile of the opening tapers towards a pivot axis of the lock member.

[0157] In some configurations, a directional lock includes a first lock member and a second lock member, each having an aperture or opening and is configured to engage a core member or filament that passes through the opening. A motion transfer element causes movement of the second lock member in response to movement of the first lock member.

[0158] In some configurations, the motion transfer element pushes the second lock member in response to movement of the first lock member, but allows the second lock member to move away from the first lock member.

[0159] In some configurations, the motion transfer element is a link, which deflects to allow the second lock member to move away from the first lock member.

[0160] In accordance with at least one of the embodiments disclosed herein, a headgear is provided comprising a top strap, a rear strap, a front strap, a yoke and a connector. The headgear is configured to be substantially inelastic and three dimensional in structure.

[0161] According to a further aspect, the headgear is constructed from a composite material, wherein a textile casing is integrally formed about a plastic core.

[0162] According to a further aspect, the headgear comprises integrally moulded labels, connections, and/or adjustment features.

[0163] According to a further aspect, a headgear component comprises a grip that is moulded to a textile strap.

[0164] According to a further aspect, the textile casing comprises a first portion that covers an inwardly-facing surface of the headgear.

[0165] According to a further aspect, the textile casing comprises a second portion that covers an outwardly-facing surface of the headgear.

[0166] According to a further aspect, the first portion and the second portion of the textile casing meet at first and second edges.

[0167] According to a further aspect, the first portion and the second portion are not connected to one another at the first and second edges.

[0168] According to a further aspect, the textile casing comprises one or more retainer holes configured to engage a retaining pin of a moulding tool.

[0169] According to a further aspect, the headgear comprises at least one flexible joint that permits the strap to bend.

[0170] According to a further aspect, the at least one flexible joint comprises a gap between portions of the plastic core and wherein the textile casing extends within the gap to connect the portion of the plastic core.

[0171] According to a further aspect, the headgear comprises at least one bridge portion extending within the flexible joint between the portions of the plastic core.

[0172] According to a further aspect, the at least one bridge portion is unitarily formed with the portions of the plastic core.

[0173] According to a further aspect, the headgear assembly comprises a top strap, a rear strap connected to the top strap at an upper connection point located on a side of a user's forehead, and a lower side strap connected to the top and rear straps at the upper connection point. The headgear assembly also comprises a first length adjusting portion adjusting the distance between the upper connection point and a frame of the respiratory interface, and a second length adjusting portion connected to the lower side strap at a lower connection point located forward of the user's ear and approximately in line with the user's mouth, wherein the second adjustment mechanism adjusts the distance between the lower connection point and the frame of the respiratoiy interface.

[0174] According to a further aspect, the top strap and the rear strap are formed unitarily as an integral structure.

[0175] According to a further aspect, the top strap, the rear strap and the lower side strap are formed unitarily as an integral structure.

[0176] According to a further aspect, the first length adjusting portion includes a fabric strap having a hook and loop fastener mechanism.

[0177] According to a further aspect, the second length adjusting portion includes a plurality of length adjusting mechanisms.

[0178] According to a further aspect, the headgear assembly comprises a top strap and a rear strap connected to the top strap at an upper connection point located on a side of a user's forehead. The headgear assembly also comprises an upper side strap connected to the top and rear straps at the upper connection point and connected to a frame of the respiratory interface. The upper side strap extends between the user's ear and eye and across the user's cheek towards the frame of the respiratory interface. The headgear assembly further comprises a lower side strap connected to the rear strap at a rear connection point located behind the user's ear. The lower side strap extends below the user's ear and across the user's cheek towards the frame of the respiratory interface. The headgear assembly additionally comprises a first length adjusting portion connected to the lower side strap and the frame of the respiratory interface. The first length adjusting portion adjusts the distance between the lower side strap and the frame of the respiratory interface.

[0179] According to a further aspect, the top strap and the rear strap are formed unitarily as an integral structure.

[0180] According to a further aspect, the top strap, the rear strap, the upper side strap and the lower side strap are formed unitarily as an integral structure.

[0181] According to a further aspect, the first length adjusting portion includes a one-way adjusting mechanism.

[0182] According to a further aspect, the headgear assembly further comprises a second length adjusting portion connected between the upper side strap and the frame of the respiratory interface, wherein the second length adjusting portion adjusts the distance between the upper side strap and the frame of the respiratory interface.

[0183] According to a further aspect, the headgear assembly comprises a top strap, a rear strap connected to the top strap at an upper connection point located on a side of a user's forehead, and a front strap connected to the top and rear straps at the upper connection point and connected to the respiratory interface. The front strap extends between the user's ear and eye and towards a bottom of the user's nose.

[0184] According to a further aspect, the top strap and the rear strap are formed unitarily as an integral structure.

[0185] According to a further aspect, the top strap, the rear strap and the front strap are formed unitarily as an integral structure.

[0186] According to a further aspect, the front strap extends across the front of the respiratoiy interface and forms a portion of a frame of the respiratory interface.

[0187] According to a further aspect, the headgear assembly further comprises a length adjusting portion connected between the front strap and the respiratory interface, wherein the length adjusting portion adjusts the distance between the front strap and the respiratory interface.

[0188] According to a further aspect, the headgear assembly comprises a top strap, a rear strap connected to the top strap at an upper connection point located on a side of a user's forehead, and a lower side strap connected to the top and rear straps at the upper connection point and extends away from the upper connection point in a substantially vertical direction. The lower strap is positioned in front of the user's ear. The headgear assembly also comprises a first length adjusting portion connected to the lower strap at a first lower connection point, the first length adjusting portion adjusting the distance between the first lower connection point and a frame of the respiratory interface. The first lower connection point is positioned in line with the user's eye and the first length adjusting portion extends across the user's cheeks just below the eyes. The headgear assembly further comprises a second length adjusting portion connected to the lower strap at a second lower connection point, the second length adjusting portion adjusting the distance between the second lower connection point and the frame of the respiratoiy interface. The second lower connection point is positioned approximately in line with a bottom of the user's nose and the second length adjusting portion extends substantially horizontally across the users cheek.

[0189] According to a further aspect, the top strap and the rear strap are formed unitarily as an integral structure.

[0190] According to a further aspect, the top strap, the rear strap and the lower side strap are formed unitarily as an integral structure.

[0191] According to a further aspect, at least one of the first or second length adjusting portions include a one-way adjusting mechanism.

[0192] In accordance with at least one of the embodiments disclosed herein, a headgear comprises a plastic core and a textile casing. The plastic core and the textile casing are formed as an integral structure by the application of a molten plastic material onto the textile casing.

[0193] According to a further aspect, the textile casing comprises a first portion that covers an inwardly-facing surface of the headgear.

[0194] According to a further aspect, the textile casing comprises a second portion that covers an outwardly-facing surface of the headgear.

[0195] According to a further aspect, the first portion and the second portion of the textile casing meet at first and second edges.

[0196] According to a further aspect, the first portion and the second portion are not connected to one another at the first and second edges.

[0197] According to a further aspect, the textile casing comprises one or more retainer holes configured to engage a retaining pin of a moulding tool.

[0198] According to a further aspect, the headgear comprises at least one flexible joint that permits the headgear to bend.

[0199] According to a further aspect, the at least one flexible joint comprises a gap between portions of the plastic core and the textile casing extends within the gap to connect the portion of the plastic core.

[0200] According to a further aspect, the headgear comprises at least one bridge portion extending within the flexible joint between the portions of the plastic core.

[0201] According to a further aspect, the at least one bridge portion is unitarily formed with the portions of the plastic core.

[0202] In accordance with at least one of the embodiments disclosed herein, a method of making a headgear comprises placing a textile casing within a moulding tool, introducing a molten plastic material into the moulding tool and into contact with the textile casing, and allowing the molten plastic material to solidify on the textile casing to form a plastic core.

[0203] According to a further aspect, the placing of the textile casing into the moulding tool comprises placing a first textile portion and a second textile portion into the moulding tool, and the introducing the molten plastic material into the moulding tool comprises introducing the molten plastic material between the first and second textile portions.

[0204] According to a further aspect, the method further comprises retaining an end of each of the first and second textile portions at which the molten plastic material is introduced within a retaining feature of the moulding tool.

[0205] According to a further aspect, the method further comprises capturing at least one edge of the textile casing between first and second separable portions of a moulding tool.

[0206] According to a further aspect, the method further comprises engaging an opening of the textile casing with a retention pin of the moulding tool.

[0207] According to a further aspect, the method further comprises securing the textile casing within the moulding tool prior to the introduction of the molten plastic material.

[0208] According to a further aspect, the securing of the textile casing comprises securing the textile casing by one or more of a static electrical charge, air pressure, retaining the textile casing with another component inserted into the moulding tool, or supporting a strip of material that forms the textile casing extending through the moulding tool on each side of the moulding tool.

[0209] According to a further aspect, the supporting the strip of material comprises supporting one end on a roll and securing a free end relative to the moulding tool. [0210] According to a further aspect, the method further comprises forming a flexible joint by providing a gap in plastic core along a length of the headgear, and extending the textile casing along the gap.

[0211] According to a further aspect, the method further comprises extending a flexible bridge portion of plastic material through the flexible joint from a portion of the plastic core on one side of the gap to a portion of the plastic core on the opposite side of the gap- [0212] In accordance with at least one embodiment disclosed herein, a headgear comprises a first strap and a second strap, wherein the first strap and the second strap cooperate to form at least one of a top strap, a rear strap and a front strap of the headgear.

[0213] In accordance with at least one of the embodiments disclosed herein, a method of making a headgear comprises placing a textile casing within a moulding tool, introducing a molten plastic material into the moulding tool and into contact with an inside of the textile casing, and allowing the molten plastic material to solidify in the textile casing to form a plastic core.

[0214] According to a further aspect, the first strap and the second strap cooperate to form the rear strap, wherein the first strap and the second strap overlap one another within the rear strap, and wherein only one of the first strap and the second strap defines the top strap.

[0215] According to a further aspect, the first strap and the second strap cooperate to form the front strap, wherein the first strap and the second strap are stacked within the front strap, and wherein the first strap and the second strap alone defines a respective one of the top strap and the rear strap.

[0216] According to a further aspect, one or both of the straps are constructed from a plastic core and a textile casing formed as an integral structure by the application of a molten plastic material onto the textile casing.

[0217] In accordance with at least one embodiment disclosed herein, a headgear includes an inner core, a first outer layer defining an inner surface of the headgear that faces the user in use, and a second outer layer defining an outer surface of the headgear that faces away from the user in use. The first layer and the second layer have different colors, textures or other indicia that permit tactile or visual differentiation of the inner surface and the outer surface.

[0218] According to a further aspect, the first outer layer or the second outer layer comprises one of a polyurethane (imitation leather), patterned polyester, wool with mesh knit, unbroken loop, nylon, a composite of spacer fabric and unbroken loop or a composite of foam an unbroken loop.

[0219] According to a further aspect, edges of one or both of the first and second outer layers extend beyond the inner core.

[0220] According to a further aspect, the inner core comprises an interior cut-out.

[0221] In accordance with at least one embodiment disclosed herein, a headgear comprises a first strap, a second strap, and a connector that couples the first strap to the second strap, wherein the connector is formed by over-moulding onto the first strap and the second strap.

[0222] According to a further aspect, the first strap and the second strap are stacked in a vertical direction within the connector.

[0223] According to a further aspect, the connector includes a portion extending between and separating the first strap from the second strap.

[0224] According to a further aspect, the connector includes a front band portion and a rear band portion separated by a bridge portion, wherein the bridge portion does not surround an entirety of both the first strap and the second strap.

[0225] According to a further aspect, the connector includes a front band portion and a rear gusset.

[0226] According to a further aspect, the front band portion and the rear gusset are separated by a bridge portion, wherein the bridge portion does not surround an entirety of both the first strap and the second strap.

[0227] In accordance with at least one embodiment disclosed herein, a strap of a headgear comprises an inner core, at least one outer layer that at least partially surrounds the inner core, and at least one air gap within the outer layer.

[0228] According to a further aspect, the at least one air gap comprises a first air gap at one lateral edge of the strap and a second air gap at the opposite lateral edge of the strap.

[0229] According to a further aspect, a portion of the inner core is externally exposed.

[0230] According to a further aspect, a conduit is positioned within the air gap.

[0231] According to a further aspect, the air gap is defined by the inner core.

[0232] In accordance with at least one embodiment disclosed herein, a strap of a headgear comprises an inner core, at least one outer layer, and at least one conduit extending lengthwise along the strap and within the outer layer.

[0233] According to a further aspect, the conduit is at least partially received within a recess of the inner core.

[0234] According to a further aspect, the conduit is completely encapsulated within the inner core.

[0235] According to a further aspect, the at least one conduit comprises a first conduit and a second conduit.

[0236] According to a further aspect, the at least one conduit is defined by the core.

[0237] In accordance with at least one embodiment disclosed herein, a strap of a headgear includes an inner core, at least one outer layer, and at least one reinforcement member.

[0238] According to a further aspect, the reinforcement member is embedded within the core.

[0239] According to a further aspect, the reinforcement member is configured to hold opposing outer layers or opposing sides of an outer layer apart from one another prior to the formation of the inner core.

[0240] In accordance with at least one embodiment disclosed herein, a strap of a headgear comprises an inner core, at least one outer layer, and at least one cushioning layer.

[0241] According to a further aspect, the cushioning layer surrounds the inner core.

[0242] According to a further aspect, a portion of the cushioning layer is externally exposed.

[0243] In accordance with at least one embodiment disclosed herein, a strap of a headgear comprises an inner core and an outer layer that at least partially surrounds the inner core, the outer layer comprising edges. The edges are embedded in the inner core.

[0244] According to a further aspect, the outer layer comprises more than one piece or more than two pieces.

[0245] According to a further aspect, a first piece of outer layer is located on one side of the strap and a second piece of the outer layer is located on an opposite side of the strap.

[0246] According to a further aspect, a third piece of the outer layer is located on one edge of the strap and a fourth piece of the outer layer is located on an opposite edge of the strap.

[0247] According to a further aspect, at least two pieces of the outer layer are located on one side of the strap.

[0248] In accordance with at least one embodiment disclosed herein, a strap of a headgear comprises an inner core and an outer layer, wherein the outer layer is textured.

[0249] According to a further aspect, the outer layer is ribbed or quilted.

[0250] According to a further aspect, the core is textured such that it imparts a texture to the outer layer.

[0251] In accordance with at least one embodiment disclosed herein, a headgear, strap or other portion thereof has one or more features as described herein or a method of making such a headgear, strap or other portion thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0252] Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0253] Figure 1 is a graph illustrating an operating envelope representing a relationship between a force created when a mask enclosure is pressurised and a headgear sizing range of potential patients;

[0254] Figure 2 illustrates the operating envelope of Figure 1 with a force curve of an elasticated headgear system superimposed;

[0255] Figure 3 illustrates the operating envelope of Figure 1 with a force curve of an exemplaiy embodiment superimposed;

[0256] Figure 4 is a graph of a force-deflection curve of an exemplaiy headgear arrangement;

[0257] Figure 4.1 illustrates a position of the exemplary headgear arrangement at a start of donning onto a user;

[0258] Figure 4.2 illustrates a position of the exemplaiy headgear arrangement at a start of retraction;

[0259] Figure 4.3 illustrates a position of the exemplaiy headgear arrangement at an end of donning;

[0260] Figure 5 is a graph containing an exemplaiy "composite" force-deflection curve;

[0261] Figure 6 is a force-area graph for maintaining an interface in sealed contact;

[0262] Figure 7 is a three-dimensional graph of a relationship between headgear force, projected seal area and head circumference;

[0263] Figure 8 A shows a force profile and elongation profile of a constant pressure therapy for elastic and inelastic headgear systems;

[0264] Figure 8B shows a force profile and elongation profile of a variable pressure therapy for elastic and inelastic headgear systems;

[0265] Figure 9 is a side view of a nasal interface having a single retention plane;

[0266] Figure 10 is a side view of a nasal interface having two retention planes;

[0267] Figure 11 is a side view of a full face mask having two retention planes;

[0268] Figure 12 is a side view of a nasal mask having two retention planes;

[0269] Figure 13 is a side view of a mask having two retention planes that converge to a single point;

[0270] Figure 13.1 is a stability chart of various headgear types;

[0271] Figure 13.2 illustrates a single retention plane interface assembly;

[0272] Figure 14 is a side view of a full face mask with forehead support having a directional locking mechanism positioned at a connection between the headgear and the mask;

[0273] Figure 15 is a side view of a full face mask with forehead support having a directional locking mechanism positioned within the headgear;

[0274] Figure 16 is a side view of a nasal mask having a directional locking mechanism on a flat strap;

[0275] Figure 17 is a side view of a nasal mask having directional locking mechanisms with a flexible core design;

[0276] Figure 18 illustrates a module of an interface assembly configured to extend between a mask or other interface and a rear portion of headgear that incorporates a directional lock arrangement;

[0277] Figure 19 illustrates an alternate module of an interface assembly configured to extend between a mask or other interface and a rear portion of headgear that incorporates a directional lock arrangement that is spaced from a biasing arrangement;

[0278] Figure 20 is a side view of an exemplary interface assembly;

[0279] Figure 21 is a side view of an exemplary full face mask;

[0280] Figure 22 is a side view of an exemplary nasal pillows mask;

[0281] Figure 23 is a rear perspective view of an exemplary headgear assembly positioned on a user;

[0282] Figure 24 is a rear perspective view of the exemplary headgear assembly in Figure 23;

[0283] Figure 25 is a rear perspective view of an exemplary headgear assembly on a user;

[0284] Figure 26 is a sectional view of the exemplary headgear assembly along a line 26-26 in Figure 25;

[0285] Figure 27 is a sectional view of the exemplary headgear assembly along a line 27-27 in Figure 25;

[0286] Figure 28 is a sectional view of the exemplary headgear assembly along a line 28-28 in Figure 25;

[0287] Figure 29 is a rear perspective view of an exemplary headgear assembly illustrating portions of the exemplary headgear constructed from various material types;

[0288] Figure 30 illustrates locations where an automatic adjuster can be positioned within an exemplary headgear assembly;

[0289] Figure 31 illustrates locations where an automatic adjuster can be positioned within an exemplary headgear assembly worn by a user;

[0290] Figure 32 illustrates an exemplary strap adjustment mechanism in assembled form;

[0291] Figure 33 is a plan view of the exemplary strap adjustment mechanism in Figure 32 separated into first and second portions;

[0292] Figure 34 is a perspective view of the second portion of the exemplary strap adjustment mechanism in Figure 32;

[0293] Figure 35 is a sectional view of a directional lock in a lock position and release position;

[0294] Figure 36 illustrates an operation cycle for a headgear incorporating a directional lock;

[0295] Figure 37 is a perspective view of an exemplary headgear assembly incorporating one or more directional locks;

[0296] Figure 38 is a perspective view of an exemplary headgear assembly incorporating one or more directional locks;

[0297] Figure 39 is a side view of an attachment member attached to a headgear rear portion of the exemplary headgear assembly in Figure 38;

[0298] Figure 40 is a perspective view of an exemplary interface assembly;

[0299] Figure 41 is a left-side perspective view of an exemplary interface assembly attached to an interface coupling portion;

[0300] Figure 42 is a side view of an exemplary interface assembly;

[0301] Figure 43 is a perspective view of a frame element of an interface member attached to an interface coupling portion;

[0302] Figure 44 is a front view of a frame element of an interface member and an interface coupling portion;

[0303] Figure 45 is a front view of a frame element of an interface member attached to an interface coupling portion;

[0304] Figure 46 is a right-side perspective view of an exemplary interface assembly attached to an interface coupling portion;

[0305] Figure 47 is a top perspective view of an exemplary interface assembly attached to a second piece of an interface coupling portion;

[0306] Figure 48 is a top perspective view a first piece of an interface coupling portion;

[0307] gure 49 is a top perspective view a second piece of an interface coupling portion;

[0308] Figure 50 is a right-side perspective view of an exemplary interface assembly;

[0309] Figure 51 is an exploded view of an exemplary interface assembly;

[0310] Figure 52 is an exploded view of an exemplary interface coupling portion;

[0311] Figure 53 is an inverted exploded view of an exemplary interface coupling portion;

[0312] Figure 54 is a top view of an exemplary collapsible headgear assembly;

[0313] Figure 55 a rear view of an exemplary collapsible headgear assembly;

[0314] Figure 56 a side view of an exemplary collapsible headgear assembly;

[0315] Figure 57 illustrates an exemplary headgear assembly coupled to a full face mask type interface;

[0316] Figure 58 illustrates the exemplary headgear assembly in Figure 57 coupled to a nasal mask;

[0317] Figure 59 illustrates the exemplary headgear assembly in Figure 57 coupled to a nasal pillows/prongs mask;

[0318] Figure 60 illustrates an exemplary headgear and interface assembly with a T-piece;

[0319] Figure 61 illustrates an exemplary headgear and mterface assembly without a T-piece;

[0320] Figure 62 illustrates an exemplary headgear and interface assembly with an interface coupling portion removably attached to an interface;

[0321] Figure 63 illustrates a first position when donning the exemplary interface assembly of Figure 62;

[0322] Figure 64 illustrates a second position when donning the exemplary interface assembly of Figure 62;

[0323] Figure 65 illustrates a third position when donning the exemplary interface assembly of Figure 62;

[0324] Figure 66 illustrates a perimeter of an adjustable interface assembly or headgear assembly at a minimum length;

[0325] Figure 67 illustrates a perimeter of an adjustable interface assembly or headgear assembly at a maximum length;

[0326] Figure 68A is a cross-sectional view of a directional lock in a locked position;

[0327] Figure 68B is a perspective cross-sectional of the directional lock in Figure 68A in the locked position;

[0328] Figure 68C is a cross-sectional view of the directional lock in Figure 68A in the unlocked position;

[0329] Figure 68D is a perspective cross-sectional of the directional lock in Figure 68A in the unlocked position;

[0330] Figure 69A is a view of a first assembly step for attaching lock washers to a housing of an exemplary directional lock;

[0331] Figure 69B is a view of a second assembly step for attaching lock washers to the housing of the exemplary directional lock of Figure 69 A;

[0332] Figure 70A is a view of a first assembly step for attaching lock washers to housings of a plurality of exemplary directional locks;

[0333] Figure 70B is a view of a second assembly step for attaching lock washers to housings of the plurality of exemplary directional locks of Figure 70A;

[0334] Figure 71 is a view of an assembly step for attaching lock washers to a housing of an exemplary directional lock;

[0335] Figure 72 is a view of an assembly step for attaching lock washers to a housing of an exemplary directional lock;

[0336] Figure 73 is a side view of an exemplary full face mask without a forehead support;

[0337] Figure 74 is a side view of an another exemplary full face mask without a forehead support;

[0338] Figure 75 is a side view of an exemplary nasal mask;

[0339] Figure 76 is an exemplary headgear system having a headgear rear portion and two retention planes;

[0340] Figure 77 is a front perspective view of an another exemplary headgear;

[0341] Figure 78 is a front view of the exemplary headgear system in Figure 77;

[0342] Figure 79 is a rear perspective view of the exemplary headgear system in Figure 77;

[0343] Figure 80 is a front view of the exemplary headgear system in Figure 77 with a mating nasal mask arrangement;

[0344] Figure 81 is a front perspective view of an exemplary cushion module and frame assembly;

[0345] Figure 82 is a front perspective view of the frame assembly connected to the housing of the headgear system;

[0346] Figure 83 is a rear view of the frame assembly connected to the housing of the headgear system;

[0347] Figure 84 is a rear view of the frame assembly removed from the housing of the headgear;

[0348] Figure 85 illustrates a validation testing of the function of a headgear arrangement that includes at least one directional locking module;

[0349] Figure 86 is a graph illustrating a relationship between force versus extension of tested exemplary headgear arrangements; and

[0350] Figure 87 is a force-extension graph illustrating force fluctuation during elongation after the transition.

[0351] Figure 88 is a perspective view of a respiratory cannula incorporating a headgear arrangement of the present disclosure, which can include at least one directional lock arrangement.

[0352] Figures 89a-89c are perspective views of additional respiratory cannulas incorporating headgear arrangements of the present disclosure, which headgear arrangements can include at least one directional lock arrangement and a headgear quick release arrangement.

[0353] Figure 90 is a perspective view of another respiratory cannula incorporating a headgear arrangement of the present disclosure, which can include at least one directional lock arrangement.

[0354] Figure 91 is a perspective view of a respiratory cannula incorporating a headgear arrangement of the present disclosure, which can include at least one directional lock arrangement and a headgear quick release arrangement.

[0355] Figure 92 is a perspective view of a respiratory cannula incorporating a headgear arrangement of the present disclosure, which can include at least one directional lock arrangement.

[0356] Figure 93 is a perspective view of a respiratory cannula incorporating a headgear arrangement of the present disclosure, which can include at least one directional lock arrangement and a headgear quick release arrangement.

[0357] Figure 94 is a perspective view of a respiratory cannula incorporating a headgear arrangement of the present disclosure, which can include at least one directional lock arrangement.

[0358] Figure 95 is a perspective view of a respiratory cannula incorporating a headgear arrangement of the present disclosure, which can include at least one directional lock arrangement and a headgear quick release arrangement.

[0359] Figure 96 is a perspective view of a respiratory cannula incorporating a headgear arrangement of the present disclosure, which can include a pair of directional lock arrangements and a pair of headgear quick release arrangements.

[0360] Figure 97 is a perspective view of a respiratory cannula incorporating a headgear arrangement of the present disclosure, which can include a pair of directional lock arrangements and a pair of headgear quick release arrangements.

[0361] Figure 98 is a perspective view of a respiratory cannula incoiporating a headgear arrangement of the present disclosure, which can include a pair of directional lock arrangements and a headgear quick release arrangement.

[0362] Figure 99 is a perspective view of a respiratory cannula incorporating a headgear arrangement of the present disclosure, which can include a pair of directional lock arrangements and a headgear quick release arrangement.

[0363] Figure 100 is a perspective view of a respiratoiy cannula incorporating a headgear arrangement of the present disclosure, which can include a pair of directional lock arrangements and a pair of headgear quick release arrangements.

[0364] Figure 101 is a perspective view of a respiratory cannula incorporating a headgear arrangement of the present disclosure, which can include at least one directional lock arrangement and a pair of headgear quick release arrangements.

[0365] Figure 102 is a perspective view of a respiratory cannula incoiporating a headgear arrangement of the present disclosure, which can include a pair of directional lock arrangements.

[0366] Figure 103 is a perspective view of an increased or controlled expiratory pressure system comprising a respiratory mask for use in combination with a nasal high flow cannula. The respiratory mask can comprise one or more directional lock arrangements.

[0367] Figure 104 is a perspective view of the respiratory mask of Figure 103.

[0368] Figure 105 is a side view of a lock member and core member of a directional lock arrangement.

[0369] Figure 106 is a graph of lock member edge sharpness versus lock member thickness illustrating a preferred operating envelope for the lock member.

[0370] Figure 107 is an enlarged view of a lock member in a locked position.

[0371] Figure 108 is an enlarged view of the lock member of Figure 107 in an unlocked position.

[0372] Figures 109a-109b illustrate several lock members with different possible cross-sectional opening shapes.

[0373] Figure 1 10 is a perspective view of a lock member having a tapered hole geometry.

[0374] Figures 1 11a and 111b illustrate lock members having alternative tapered hole geometries.

[0375] Figure 112 is a graph of force versus distance illustrating the progressive holding force profile of the tapered hole geometries in comparison with a linear holding force profile.

[0376] Figures 113a and 113b illustrate a directional lock arrangement comprising a pair of lock members and a motion transfer element for transferring motion between the lock members. Figure 113a illustrates the directional lock arrangement in an unlocked position and Figure 113b illustrates the directional lock arrangement in a locked position.

[0377] Figures 114a and 114b illustrate another directional lock arrangement comprising a pair of lock members and an alternative motion transfer element for transferring motion between the lock members. Figure 114a illustrates the directional lock arrangement in an unlocked position and Figure 114b illustrates the directional lock arrangement in a locked position.

[0378] Figure 115 illustrates a respiratory mask system comprising a headgear arrangement incorporating at least one directional lock arrangement. The directional lock arrangement is located behind the ear of the user.

[0379] Figure 116 illustrates possible locations for placement of a directional lock arrangement on a user.

[0380] Figure 117 illustrates a possible location for placement of a directional lock behind an ear of the user, with the placement area shown relative to bones of the skull.

[0381] Figure 118A is a side view of the headgear of the present disclosure being worn by a user.

[0382] Figure 118B is a perspective view of the headgear of the present disclosure.

[0383] Figure 119 is a cross-sectional view of a strap that forms part of the presently disclosed headgear.

[0384] Figure 120 is a third angle orthographic view of one half of an injection moulding tool configured to mould a strap component similar to the headgear of the present disclosure.

[0385] Figure 121 is an isometric view of the strap component produced by the injection moulding tool of Figure 120.

[0386] Figure 122 is a cross-sectional view BB of the injection moulding tool of Figure 120 with a textile casing placed inside.

[0387] Figure 123 is an enlarged view of the cross-section AA of the injection moulding tool of Figure 120 with a textile casing placed inside.

[0388] Figure 124A is a perspective view of a second embodiment of the headgear of the present disclosure.

[0389] Figure 124B is an enlarged cross-sectional view of a size adjustment system of the second embodiment of the headgear of the present disclosure.

[0390] Figure 125A is a cross-sectional view of a second embodiment of the size adjustment system of Figures 124A and 124B.

[0391] Figure 125B is a plan view of the first strap of the size adjustment system of Figure 8 A.

[0392] Figure 125C is a perspective view of a first strap of an alternative size adjustment system.

[0393] Figure 125D is a cross-sectional view of connected first and second straps of the size adjustment system of Figure 125C.

[0394] Figure 125E is a cross-sectional view of unconnected first and second straps of the size adjustment system of Figure 125C.

[0395] Figure 125F is a perspective exploded view of another alternative size adjustment system.

[0396] Figure 125G is a close-up perspective exploded view of the size adjustment system of Figure 125F.

[0397] Figure 125H is a top-down view of the first strap of the size adjustment system of Figure 125F.

[0398] Figure 1251 is a cross-sectional view of the second strap of the size adjustment system of Figure 125F.

[0399] Figure 126 is a perspective view of a breathing apparatus with cushion pads that are connected using the size adjustment systems of Figures 124A and 124B.

[0400] Figures 127A and 127B are plan views of a connection between breathing apparatus components.

[0401] Figure 128 is a plan view of a headgear component with a moulded grip.

[0402] Figure 129 is a cross-sectional view of a mould tool configured to form the headgear component of Figure 128.

[0403] Figure 130 is a side view of a headgear strap portion having a relatively inelastic core, a fabric casing on at least one surface of the core and a flexible joint between portions of the core.

[0404] Figure 131 is a sectional view of the headgear strap portion of Figure 130 taken along line 14-14 of Figure 130.

[0405] Figure 132 is a side view of a headgear strap portion having a relatively inelastic core, a fabric casing on at least one surface of the core and a flexible joint between portions of the core, wherein the flexible joint comprises flexible bridge portions extending between the portion of the core.

[0406] Figure 133 is a cross sectional view of the headgear strap portion of Figure 132 taken along line 16-16 of Figure 132.

[0407] Figure 134 illustrates a system for forming a headgear strap portion utilizing a static electrical charge to hold the fabric casing in place within a forming mould.

[0408] Figure 135 illustrates a system for forming a headgear strap portion utilizing air pressure to hold the fabric casing in place within a forming mould.

[0409] Figure 136 illustrates a system for forming a headgear strap portion utilizing one or more components for holding the fabric casing in place within a forming mould.

[0410] Figure 137 illustrates a system for forming a headgear strap portion utilizing a roll of material for feeding the fabric casing into a forming mould.

[0411] Figure 138 illustrates a headgear having a first strap and a second strap.

[0412] Figure 139A is a sectional view of the second strap and Figure 139B is a sectional view of the first strap.

[0413] Figure 139C is a sectional view of an alternative strap in which a core of the strap includes a recess configured to receive a seam of a cover layer of the strap.

[0414] Figure 139D is a sectional view of another alternative strap in which the core has one or more recesses occupying a substantial portion of a width direction of the core and the seam of the cover layer is located within the recess.

[0415] Figure 139E is a sectional view of yet another alternative strap illustrating an alternative seam arrangement in which the seam of the cover layer is folded over onto the surface of the cover layer.

[0416] Figure 140A is a view of an outer layer of the first strap and Figure 140B is a view of an outer layer of the second strap.

[0417] Figure 141 illustrates a headgear having a first strap and a second strap.

[0418] Figure 142 A is a sectional view of the first strap and Figure 142B is a sectional view of the second strap.

[0419] Figure 143A is a view of an outer layer of the first strap and Figure 143B is a view of an outer layer of the second strap.

[0420] Figure 144 illustrates a headgear having an inner core, a first outer layer and a second outer layer.

[0421] Figure 145 is a sectional view of a portion of the headgear of Figure 144.

[0422] Figure 146A is a view of the first outer layer and Figure 146B is a view of the second outer layer of the headgear of Figure 144.

[0423] Figure 147 illustrates a headgear having an inner core, a first outer layer and a second outer layer.

[0424] Figure 148 is a sectional view of a portion of the headgear of Figure 147.

[0425] Figure 149A is a view of the first outer layer and Figure 148B is a view of the second outer layer of the headgear of Figure 147.

[0426] Figure 150 illustrates a headgear having an inner core, a first outer layer and a second outer layer.

[0427] Figure 151 is a sectional view of a portion of the headgear of Figure 150.

[0428] Figure 152A is a view of the first outer layer and Figure 152B is a view of the second outer layer of the headgear of Figure 150.

[0429] Figure 153 illustrates a headgear having an inner core, a first outer layer and a second outer layer.

[0430] Figure 154 is a sectional view of a portion of the headgear of Figure 153.

[0431] Figure 155 illustrates a headgear having an inner core, a first outer layer and a second outer layer.

[0432] Figure 156 is a sectional view of a portion of the headgear of Figure 155.

[0433] Figure 157A is a view of the first outer layer and Figure 157B is a view of the second outer layer of the headgear of Figure 155.

[0434] Figure 158 is a sectional view of a headgear strap arrangement having a core and one or more outer layers.

[0435] Figure 159 is a side view of the core of the headgear strap arrangement of Figure 158.

[0436] Figure 160 is a sectional view of a headgear strap arrangement having a core and one or more outer layers.

[0437] Figure 161 is a side view of the core of the headgear strap arrangement of Figure 160.

[0438] Figure 162 is a sectional view of a headgear strap arrangement having a core and one or more outer layers.

[0439] Figure 163 is a side view of the core of the headgear strap arrangement of Figure 162.

[0440] Figure 164 is a sectional view of a headgear strap arrangement having a core and one or more outer layers.

[0441] Figure 165 is a side view of the core of the headgear strap arrangement of Figure 164.

[0442] Figure 166 is a sectional view of a headgear strap arrangement having a core and one or more outer layers.

[0443] Figure 167 is a side view of the core of the headgear strap arrangement of Figure 166.

[0444] Figure 168 is a sectional view of a headgear strap arrangement having a core and one or more outer layers.

[0445] Figure 169 is a side view of the core of the headgear strap aiTangement of Figure 168.

[0446] Figure 170 is a sectional view of a headgear strap arrangement having a core and one or more outer layers.

[0447] Figure 171 is a side view of the core of the headgear strap arrangement of Figure 170.

[0448] Figure 172 is a sectional view of a headgear strap arrangement having a core and one or more outer layers.

[0449] Figure 173 is a side view of the core of the headgear strap arrangement of Figure 172.

[0450] Figure 174 is a perspective view of a headgear having a first strap and a second strap.

[0451] Figure 175A is a sectional view of a portion of the headgear of Figure 174.

[0452] Figure 175B is a sectional view of an alternative arrangement of the straps of the headgear of Figure 174.

[0453] Figure 175C is a sectional view of another alternative arrangement of the straps of the headgear of Figure 174.

[0454] Figure 176 is a perspective view of a headgear having at least a first strap and a second strap.

[0455] Figure 177 is an enlarged view of the headgear of Figure 176 including a coupling arrangement that couples at least the first strap and the second strap.

[0456] Figure 178 is a sectional view of a portion of the headgear of Figure 176 taken through the coupling arrangement of Figure 177.

[0457] Figure 179 is a perspective view of a headgear having at least a first strap and a second strap.

[0458] Figure 180 is an enlarged view of the headgear of Figure 179 including a coupling arrangement that couples at least the first strap and the second strap.

[0459] Figure 181 is a sectional view of a portion of the headgear of Figure 179 taken through the coupling arrangement of Figure 180.

[0460] Figure 182 is a perspective view of a headgear having at least a first strap and a second strap.

[0461] Figure 183 is an enlarged view of the headgear of Figure 182 including a coupling arrangement that couples at least the first strap and the second strap.

[0462] Figure 187 is a sectional view of a portion of the headgear of Figure 182 taken through the coupling arrangement of Figure 183.

[0463] Figure 185 is a perspective view of a headgear having at least a first strap and a second strap.

[0464] Figure 186 is an enlarged view of the headgear of Figure 185 including a coupling arrangement that couples at least the first strap and the second strap.

[0465] Figure 187 is a sectional view of a portion of the headgear of Figure 185 taken through the coupling arrangement of Figure 186.

[0466] Figure 188 is a perspective view of a headgear having at least a first strap and a second strap.

[0467] Figure 189 is an enlarged view of the headgear of Figure 188 including a coupling arrangement that couples at least the first strap and the second strap.

[0468] Figure 190 is a sectional view of a portion of the headgear of Figure 188 taken through the coupling arrangement of Figure 189.

[0469] Figure 191 is a perspective view of a headgear having at least a first strap and a second strap.

[0470] Figure 192 is an enlarged view of the headgear of Figure 191 including a coupling arrangement that couples at least the first strap and the second strap.

[0471] Figure 193 is a sectional view of a portion of the headgear of Figure 191 taken through the coupling arrangement of Figure 192.

[0472] Figure 194 is a sectional view of a headgear strap having a core and an outer layer with one or more air gaps or voids between the outer layer and the core.

[0473] Figure 195 is a sectional view of a headgear strap having a core and an outer layer with one or more conduits between the outer layer and the core.

[0474] Figure 196 is a sectional view of another headgear strap having a core and an outer layer with one or more conduits between the outer layer and the core.

[0475] Figure 197 is a sectional view of a headgear strap having a core and an outer layer with one or more conduits at least partially surrounded by the core.

[0476] Figure 198 is a sectional view of another headgear strap having a core and an outer layer with one or more conduits at least partially surrounded by the core.

[0477] Figure 199 a sectional view of a headgear strap having a core and an outer layer with a pair of conduits defined by the core.

[0478] Figure 200 is a sectional view of a headgear strap having a core and an outer layer with an air gap between the outer layer and the core.

[0479] Figure 201A is a sectional view of the headgear strap of Figure 200 in a first position against a surface.

[0480] Figure 201B is a sectional view of the headgear strap of Figure 200 in a second position against the surface.

[0481] Figure 202 is a sectional view of a headgear strap having a core and an outer layer with an air gap between the outer layer and the core, wherein a portion of the core is externally exposed.

[0482] Figure 203 is a sectional view of another headgear strap having a core and an outer layer with an air gap between the outer layer and the core, wherein a portion of the core is externally exposed.

[0483] Figure 204 is an exploded view of an outer layer and reinforcement members of a headgear strap.

[0484] Figure 205 is a sectional view of a headgear strap incorporating the outer layer and reinforcement members of Figure 204.

[0485] Figure 206 is a sectional view of a headgear strap having a core, a first outer layer, a second outer layer and one or more reinforcement or separating members that separate the outer layers prior to the introduction of the core material.

[0486] Figure 207 is a sectional view of a headgear strap having a core, a first outer layer, a second outer layer and a reinforcement member encapsulated in the core.

[0487] Figure 208 is a sectional view of a headgear strap having a core, a cushioning layer and an outer layer.

[0488] Figure 209 is a sectional view of another headgear strap having a core, a cushioning layer and an outer layer, wherein a portion of the cushioning layer is externally exposed.

[0489] Figure 210 is a side view of a portion of a headgear having several straps and a connector that connects two or more of the straps.

[0490] Figure 211 is a sectional view of the connector and one of the straps of Figure 210.

[0491] Figure 212 is a sectional view of a headgear strap having a core and a single piece, seamless outer layer.

[0492] Figure 213 is a sectional view of a headgear strap having a core and a single piece outer layer having a seam, with edges of the outer layer embedded within the core.

[0493] Figure 214 is a sectional view of another headgear strap having a core and a single piece outer layer having a seam, with edges of the outer layer embedded within the core.

[0494] Figure 215 is a sectional view of a headgear strap having a core and a two piece outer layer having a pair of seams, with edges of the outer layer pieces embedded within the core.

[0495] Figure 216A is a sectional view of a two piece outer layer without the core and Figure 216B is a sectional view of the two piece outer layer after the core has been formed.

[0496] Figure 217 is a sectional view of a headgear strap having a core and a four piece outer layer having four seams, with edges of the outer layer pieces embedded within the core.

[0497] Figure 218 is a sectional view of another headgear strap having a core and a three piece outer layer having three seams, with edges of the outer layer pieces embedded within the core.

[0498] Figure 219 is a perspective view of a headgear strap having a core and a textured outer layer, with a portion of the outer layer cut away to expose the core.

[0499] Figure 220 is a perspective view of a headgear strap having a core and a quilted outer layer, with a portion of the outer layer cut away to expose the core.

[0500] Figure 221 is a sectional view of a headgear layer having a core and an outer layer, wherein the core imparts a textured shape to the outer layer.

[0501] Figure 222 is a perspective view of a headgear having a first strap and a second strap.

[0502] Figure 223 is a sectional view of the first strap of the headgear of Figure

222.

[0503] Figure 224 is a sectional view of the second strap of the headgear of Figure

222.

[0504] Figure 225 is a perspective view of a headgear having a first strap, a second strap and a connection between the first strap and the second strap.

[0505] Figure 226 is an enlarged view of a portion of the headgear of Figure 225 including the connection.

[0506] Figure 227 is a sectional view of the connection of Figure 226.

[0507] Figure 228 is a perspective view of a headgear having a first strap, a second strap and a connection between the first strap and the second strap.

[0508] Figure 229 is an enlarged view of the portion of the headgear of Figure 228 including the connection.

[0509] Figure 230 illustrated several possible sectional views of the straps within the connection.

[0510] Figure 231 is a sectional view of the second strap of the headgear of Figure

228.

[0511] Figure 232A is a top-down view of a front strap and bifurcated straps of an intra-moulded bifurcated headgear.

[0512] Figure 232B is a perspectiveview of first and second cover layers joined together to form a strap of the intra-moulded bifurcated headgear of Figure 232A.

[0513] Figure 232C is a cross-sectional view of first and second cover layers joined together to form a strap of the intra-moulded bifurcated headgear of Figure 232A.

[0514] Figure 233 is a perspective view of the intra-moulded bifurcated headgear of Figure 232A having front straps that are partially rigid.

[0515] Figure 234 is a perspective view of the intra-moulded bifurcated headgear of Figure 232A having rigid front straps and partially rigid bifurcated straps.

[0516] Figure 235 is a perspective view of the intra-moulded bifurcated headgear of Figure 232A having rigid front and bifurcated straps.

[0517] Figure 236A is a perspective view of a mould tool configured to form the intra-moulded bifurcated headgear configuration of Figures 232 A to 235.

[0518] Figure 236B is a cross-sectional view of the mould tool of Figure 236A along a line A-A.

[0519] Figure 236C is a cross-sectional view of a mould tool configured to secure in place a fabric casing within the mould tool.

[0520] Figure 236D is a cross-sectional view of a mould tool having retention spikes to secure in place a fabric casing within the mould tool.

[0521] Figure 236E is a partial perspective view of the mould tool of Figure 236D showing retention spikes to secure in place a fabric casing within the mould tool.

[0522] Figure 236F is a cross-sectional view of the mould tool of Figure 236D showing retention spikes piercing but not extending through the fabric casing.

[0523] Figure 236G is a cross-sectional view of the mould tool of Figure 236D showing retention spikes piercing through the fabric casing.

[0524] Figure 237A is a perspective view of a mould tool for forming a headgear using a woven fabric casing.

[0525] Figure 237B is a cross-sectional view of the mould tool of Figure 237A.

[0526] Figure 238 is a perspective cross-sectional view of an alternative construction of an intra-moulded strap having a core, cover layers and rails.

[0527] Figure 239A is a cross-sectional view of an alternative construction of an intra-moulded strap having an airpocket core, a cover layer and intra-moulded rails.

[0528] Figure 239B is a perspective view of the intra-moulded strap of Figure

239A.

[0529] Figure 239C is a cross-sectional view of the intra-moulded strap of Figure 239A when donned by the user.

[0530] Figure 240A is a perspective cross-sectional view of an alternative construction of an intra-moulded strap having a structured core.

[0531] Figure 240B is a cross-sectional view of a mould tool for constructing the structured core of the intra-moulded strap in Figure 240A.

[0532] Figure 241A is a perspective view of an alternative construction of an intra-moulded strap having a complex 3D shape with continuously variable geometry and cross-section along its length.

[0533] Figure 241B is a cross-sectional view of the intra-moulded strap of Figure 241 A along a line A- A.

[0534] Figure 241C is a cross-sectional view of the intra-moulded strap of Figure 241 A along a line B-B.

[0535] Figure 242A is a perspective cross-sectional view of an alternative intra-moulded strap having embossed branding logos.

[0536] Figure 242B is a perspective cross-sectional view of an alternative intra-moulded strap having laser cut branding logos.

[0537] Figure 242C is a perspective cross-sectional view of the alternative intra-moulded strap of Figure 242B.

[0538] Figure 242D is a perspective cross-sectional view of an alternative intra-moulded strap having laser cut portion removed to expose core material.

[0539] Figure 242E is a perspective cross-sectional view of an alternative intra-moulded strap having an embossed indicator and a protruding indicator formed from protruding exposed core material.

[0540] Figure 242F is a perspective cross-sectional view of an alternative intra-moulded strap having protruding grip bumps with embossed features.

[0541] Figure 242G is a perspective cross-sectional view of an alternative intra-moulded strap having embossed and protruding grip bumps.

[0542] Figure 243A is a perspective cross-sectional view of an alternative intra-moulded strap having over-moulded branding logos.

[0543] Figure 243B is a perspective cross-sectional view of an alternative intra-moulded strap having over-moulded grip bumps.

[0544] Figure 243C is a cross-sectional view of the alternative intra-moulded strap having over-moulded grip bumps of Figure 243B along a line A-A.

[0545] Figure 244A is a rear perspective view of a moulded headgear configuration having a single back strap.

[0546] Figure 244B is a cross-sectional view of the moulded headgear configuration of Figure 244 A along a line A-A.

[0547] Figure 245A is a side perspective view of a moulded headgear configuration having a lower strap connected to a crown strap by an arched connector.

[0548] Figure 245B is a cross-sectional view of the moulded headgear configuration of Figure 245 A along a line A-A.

[0549] Figure 245C is a side view of the moulded headgear configuration of Figure 245A.

[0550] Figure 246 is a rear perspective view of a moulded headgear configuration having a rigid front strap and elastic rear and crown straps.

[0551] Figure 247A is a rear perspective view of a moulded bifurcating headgear configuration having a having a variable knit intra-mould.

[0552] Figure 247B is a cross-sectional view of the moulded headgear configuration of Figure 247 A along a line A-A.

[0553] Figure 247C is a cross-sectional view of the moulded headgear configuration of Figure 247A along a line B-B.

[0554] Figure 247D is a moulding tool for forming the moulded headgear configuration of Figure 247 A.

[0555] Figure 248A is a side perspective view of a moulded headgear configuration having a fully integrated bifurcated rear strap and crown strap.

[0556] Figure 248B is a partial exploded perspective view of the moulded headgear configuration of Figure 248A.

[0557] Figure 248C is a cross-sectional perspective view of the moulded headgear configuration of Figure 248A along a line A-A.

[0558] Figure 249 A is a side perspective view of a moulded headgear configuration having core material exposed and formed on the outside surface of the outer cover.

[0559] Figure 249B is cross-sectional perspective view of the moulded headgear configuration of Figure 248 A having the core material recessed within the outer cover.

[0560] Figure 249C is a cross-sectional perspective view illustrating an alternative construction of the moulded headgear configuration of Figure 248A having core material positioned over the outer cover without recessing into the outer cover.

[0561] Figure 250 is a side view of an exemplary intra-moulded headgear configuration for use in combination with a full-face mask.

[0562] Figure 251 is a side view of an exemplary intra-moulded headgear configuration having a below the ear lower strap for use in combination with a nasal mask.

[0563] Figure 252 is a side view of an exemplary intra-moulded headgear configuration for use in combination with a nasal pillows mask.

[0564] Figure 253 is a side view of an exemplary intra-moulded headgear configuration for use in combination with a nasal mask.

[0565] Throughout the drawings, reference numbers can be reused to indicate general correspondence between reference elements. The drawings are provided to illustrate example embodiments described herein and are not intended to limit the scope of the disclosure.

DETAILED DESCRIPTION

[0566] Embodiments of systems, components and methods of assembly and manufacture will now be described with reference to the accompanying figures, wherein like numerals refer to like or similar elements throughout. Although several embodiments, examples and illustrations are disclosed below, it will be understood by those of ordinary skill in the art that the inventions described herein extends beyond the specifically disclosed embodiments, examples and illustrations, and can include other uses of the inventions and obvious modifications and equivalents thereof. The terminology used in the description presented herein is not intended to be interpreted in any limited or restrictive manner simply because it is being used in conjunction with a detailed description of certain specific embodiments of the inventions. In addition, embodiments of the inventions can comprise several novel features and no single feature is solely responsible for its desirable attributes or is essential to practicing the inventions herein described.

[0567] Certain terminology may be used in the following description for the purpose of reference only, and thus are not intended to be limiting. For example, terms such as "above" and "below" refer to directions in the drawings to which reference is made. Terms such as "front," "back," "left," "right," "rear," and "side" describe the orientation and/or location of portions of the components or elements within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the components or elements under discussion. Moreover, terms such as "first," "second," "third," and so on may be used to describe separate components. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import.

[0568] As used herein the term 'substantially inelastic' shall refer to the ability of a headgear or material to resist stretching relative to the loads to which it may be subjected. Thus, a headgear or material may be substantially inelastic in one direction and may be somewhat elastic in another direction. In some configurations, the headgear or material is configured to be substantially inelastic in a direction in which loads are applied by the therapy with which the headgear or material is intended for use. A substantially inelastic

headgear or material, for example, can resist stretching that would compromise a seal of a respiratory mask in a sealed system under normal or expected conditions. In an unsealed system, a substantially inelastic headgear or material, for example, can resist stretching that would compromise the appropriate placement of the respiratory interface in response to normal or expected conditions, such as hose pull forces or movement of the user. When the expected loading forces are relatively low, the headgear or material may have greater elasticity because the load will not be sufficient to cause stretching. Conversely, if it is expected that the headgear and/or material will be subjected to high loading forces, then greater inelasticity will be required to resist stretching.

[0569] Some embodiments disclosed herein involve a headgear system and/or an interface assembly incorporating a headgear system that upon fitment to the head of a user automatically adjusts to the correct size and, once in use, transforms in properties from an elasticated "stretchy" strap/strapping to an "inelastic" strap/strapping. In some configurations, the headgear (alone or as integrated in an interface assembly) exhibits a relatively small contraction force that tends to shorten the headgear. When coupled to a mask, the headgear and mask cooperate to define a perimeter of the interface assembly, which is reduced in length as a result of the contraction force toward a minimum perimeter length. Although not likely to be perfectly circular, the perimeter length is often referred to as a "circumference." Thus, with such an arrangement, the interface assembly can be positioned on the user's head and will automatically contract to or very near a proper head size, in a manner similar to an elasticated or "stretchy" headgear. The contraction force preferably is sufficient to support the weight of the interface assembly and at least substantially keep the interface assembly in place on the user's head at the smallest head size or minimum useful perimeter length of the interface assembly, which may or may not coincide with the minimum perimeter length. In some configurations, the retraction force can be sufficient to support the weight of a nasal cannula or other small interface, which can have a weight of about 50 grams, for example. In other configurations, the retraction force can be between about 0.5 Newtons and about 5.2 Newtons, or between about 1 Newton and about 2.6 Newtons, or between about 1 Newton and about 1.5 Newtons, including any value and sub-range within these ranges, hi other configurations, the retraction force may be insufficient to support the weight of the interface and may require manual assistance to move the interface to a sealed position on the user's face. However, preferably, once the headgear is sufficiently retracted, it is then held in place by, for example, the directional lock(s). In some configurations, the contraction force is only sufficient or is configured to support the weight of the headgear.

[0570] However, in at least some configurations, the contraction force is less than is necessary to maintain the mask in sealed contact with the user's face during treatment/use. That is, the contraction force, alone, cannot resist the blow-off force. In some configurations, the contraction force is insufficient to resist the blow-off force throughout a range of usable perimeter lengths or headgear sizes. Therefore, the headgear and/or interface assembly also exhibits an inelastic behavior in response to forces tending to elongate the headgear or increase the perimeter length of the interface assembly. The headgear and/or interface assembly can have a locked mode that can produce a locking force tending to resist expansion, elongation or lengthening of the perimeter length. The locking force can be sufficient to resist elongation, or at least any significant elongation, of the perimeter length in response to blow-off forces. In some configurations, the locking force is sufficient to resist elongation in response to the highest blow-off forces expected with a variety of uses or treatments (e.g., Bi-Level or CPAP, NIV, etc.). In some configurations, the locking force may be selected for one or more particular uses/therapies, but may not be suitable for all uses/therapies. In some configurations, the locking force may be selected to resist elongation in response to forces in addition to blow-off forces, such as hose pull forces, for example. Such additional forces can be referred to collectively herein as "hose pull forces" and such additional resistance to elongation can be referred to herein as a "reserve."

[0571] In some configurations, the headgear and/or interface assembly also exhibits a yield force, above which expansion or elongation of the perimeter length is permitted. Preferably, the yield force is greater than the expected blow-off force. In some configurations, the yield force is greater than the expected blow-off force and the hose pull force. Thus, such a headgear and/or interface assembly has a reserve. Preferably, the yield force is set low enough that a user can at least relatively conveniently apply an elongation force to the headgear and/or interface assembly sufficient to exceed the yield force in order to permit the interface assembly to lengthen and to be applied to the user's head. As described above, the contraction force reduces the perimeter length toward a proper head size.

[0572] In some configurations, the headgear and/or interface assembly automatically transitions between a contraction mode, a locked mode and a yield mode in response to the presence or absence of external forces. For example, the headgear and/or interface assembly moves toward or to the minimum perimeter length in the absence of external lengthening or expanding forces. A lengthening or expansion force that is greater than the yield force can be applied to increase the perimeter length of the headgear and/or interface assembly to a length sufficient to permit the interface assembly to be positioned on the user's head. Once the lengthening or expansion force is removed (or reduced to below the contraction force), the contraction force acts to automatically reduce the perimeter length to or substantially to the proper head size such that the interface assembly is supported on the user's head. Upon the start of treatment (application of blow-off force) and/or application of hose pull force, the headgear and/or interface assembly automatically transforms to the locked mode to resist elongation, or at least resist any significant elongation, or increase of the perimeter length. At the end of treatment, or at any time as desired, a force above the yield force can be applied to the headgear and/or interface assembly to increase the perimeter length and permit removal of the interface assembly from the user's head.

[0573] Advantageously, with such an arrangement, micro-adjustments of the perimeter length of the headgear and/or interface assembly can be accomplished quickly and conveniently. For example, during treatment or use, the mask can be manipulated to effect micro-adjustment of the perimeter length. For instance, in the event of a leak between the mask and the user's face, the mask can be wiggled or otherwise moved to effect a micro-adjustment of the perimeter length to address the leak. In some cases, the seal of the mask may be compressed against the user's face, which can allow the contraction force to automatically reduce the perimeter length. Upon release of the mask, the headgear and/or interface assembly locks at, or very near, the reduced perimeter length. Thus, such configurations permit the headgear and/or interface assembly to micro-adjust, or move to an adjusted perimeter length, as a result of small manipulations (e.g., wiggling) of the mask. Manipulation of other portions of the interface assembly (e.g., headgear or breathing

tube/gases conduit) can similarly result in micro-adjustment. Because of the nature of the human head and/or the conditions under which interface assemblies are used, quick and convenient micro-adjustment can dramatically improve performance and user satisfaction of an interface assembly. Treatment often occurs at night and/or under other situations when the user is lying down. Thus, the headgear can be in contact with surface, such as a pillow or bed. Movement of the user's head relative to such surfaces can cause movement of the headgear, which can alter the fit of the headgear. For example, hair can move or "compress" beneath the headgear, which can alter the fit. The headgear straps may move up, down or rotationally on the head, which can alter the fit. Such alterations in fit can result in leaks between the mask and the user's face. The above-described adjustment technology can permit such changes in fit to be addressed automatically or with small manipulations of the mask or other portions of the interface assembly. Moreover, the interface assembly can be removed and reapplied and automatically adjust to at or veiy near a proper headgear size. In contrast, if conventional non-stretch headgear is moved from its desired adjustment position, such as by mistake or as a result of cleaning, it can be difficult and time-consuming to reestablish the desired adjustment position. Conventional elasticated headgear addresses the adjustment issue, but because the contraction force must resist the highest expected blow-off and hose pull forces at the smallest useable headgear size, elasticated headgear applies a relatively large pressure to the user's head that is only partially relieved by the application of blow-off force. Such pressure may be substantial for a user with a relatively large head size and low treatment pressure.

[0574] As is described below with reference to specific directional lock arrangements, in some configurations, some amount of movement occurs in the headgear and/or interface assembly during transition from the elastic mode to the locked mode. For example, with some directional lock arrangements, the perimeter length may increase slightly during the transition from elastic mode to locked mode. In some cases, there exists a compromise between increased yield force and reduced perimeter length change during transition. Thus, references to any particular positions of the headgear and/or interface assembly or perimeter lengths can include such slight length changes during transition, if present.

[0575] The following example of the above-described adjustment technology is based on the delivery of CPAP. The series of graphs describe a typical operating envelope that a headgear system must be designed to operate over and how various current embodiments operate relative to that envelope. The envelope may comprise an entire CPAP treatment universe, that is, an entire range of typical, probable or possible CPAP pressures and an entire range of typical, probable or possible head sizes. Or, the envelope may comprise a subset of the CPAP treatment universe, such as a subset of pressures (e.g., low pressure or high pressure CPAP) or head (headgear or interface assembly) sizes (e.g., small, medium or large). The principles discussed in connection with CPAP treatment may apply to other treatments, as well.

[0576] Figure 1 is a graph that illustrates a relationship between the force that is created when a mask enclosure is pressurised and the headgear sizing range that is likely to be encountered across the range of potential patients. The operating envelope is illustrated as a rectangular area defined between minimum and maximum forces and minimum and maximum head sizes (circumferences).

[0577] Figure 2 illustrates the operating envelope of Figure 1 with the performance characteristics (force curve) of an elasticated headgear system superimposed. It is apparent that for the elasticated system to offer sufficient performance across the mask system operating envelope, it must provide a greater force than the mask system can generate. Thus, at low CPAP pressures, the headgear provides a much greater force than is necessary to counteract the blow-off force. The additional force is applied a pressure to the user over an area defined by the mask and headgear, which is concentrated primarily at the mask and at the back of the head. The area of the headgear can be increased to apply the force over a larger area, thereby reducing the applied pressure. However, large headgear can be annoying or uncomfortable. For example, such large headgear can retain heat over a larger area than desirable.

[0578] Figure 3 illustrates the operating envelope of Figure 1 with the performance of an example of a headgear system having the above-described automatic adjustment technology superimposed. In the illustrated example, the force generated by the headgear and/or interface assembly is sufficient to balance the forces generated by the

pressurization of the enclosed area of the mask. In essence, the example headgear system automatically adjusts to the appropriate head size (circumference or perimeter length) with a relatively low contraction force and then provides a retention force "on-demand" that is matched to the actual CPAP pressure. Thus, the example headgear system can automatically adjust to meet the needs of any potential point within the CPAP envelope.

[0579] Figure 4 illustrates a graph of a force-deflection curve of an example of a headgear arrangement or interface assembly comprising a headgear arrangement. The deflection axis of the graph may represent the circumference or perimeter length of the headgear arrangement or interface assembly. The circumference or perimeter length, in turn, can represent the head circumference of a particular user when the headgear arrangement or interface assembly is fitted to the user. Figures 4.1-4.3 illustrate several discrete positions of a user putting on ("donning") and micro-adjusting an example interface assembly comprising a headgear arrangement. The graph of Figure 4 is described below with additional reference to the donning positions of Figures 4.1-4.3.

[0580] The graph of Figure 4 also illustrates an operating envelope 10 relevant to the headgear arrangement or interface assembly, which may be the same operating envelope as shown and described above with respect to Figures 1-3. The operating envelope 10 is illustrated as a rectangular area defined between minimum and maximum forces applied to the headgear arrangement or interface assembly as a result of the therapy and minimum and maximum head sizes or circumferences/perimeter lengths of the headgear arrangement. The operating envelope 10 can be specific to a therapy (e.g., CPAP or bi-level PAP) or can cover multiple therapies. Similarly, the head size or circumference/perimeter length can be specific to a size of headgear arrangement or can cover multiple sizes. The operating envelope 10 can be used to establish functional or behavioral criteria of a particular headgear airangement and is utilized herein to illustrate features or behaviors of certain disclosed embodiments.

[0581] A graph containing an example force-deflection curve of an example headgear arrangement or interface assembly (referred to as "headgear" for convenience in the discussion of the graph) is illustrated relative to the example operating envelope 10. The curve originates at or near the origin of the graph, which may represent approximately zero force and a minimum circumference or perimeter length (referred to as "circumference" for

convenience in the discussion of the graph) of the headgear. The minimum circumference is greater than zero, but typically at a value below a minimum head circumference (taking into consideration the interface, if any) of the intended user or range of users.

[0582] As illustrated in Figure 4.1, to place the headgear 100 onto the user, typically, the headgear 100 will be elongated to a circumference greater than the actual head circumference of the user. Typically, a rear portion of the headgear 100 will be placed on the rear of the user's head and the user will grasp the front of the headgear 100 (e.g., the mask or other interface) and apply a pulling force to elongate the headgear 100 and move the mask or other interface over the crown of the head and toward the face.

[0583] As illustrated in the graph of Figure 4, the example force-deflection curve initially rises with a steep pitch, in which the force increases a substantial amount with a relatively small increase in the circumference. In some configurations, the force-deflection curve rises above the maximum force level of the operating envelope 10 before reaching the minimum circumference of the operating envelope 10. This portion of the curve can be referred to as an initial elongation portion 12a.

[0584] At some location above the maximum force of the operating envelope 10, the force-deflection curve transitions to a shallower pitch, in which the circumference increases a substantial amount with a relatively small increase in the force. This shallow pitch portion of the force-deflection curve can relate to a yield force of the retention arrangement of the headgear 100. Preferably, the shallow pitch portion, which can be referred to as an elongation portion 12b, of the force-deflection curve extends at or above the maximum force level of the operating envelope 10 along a portion or an entirety of the circumference range of the operating envelope 10. In some configurations, the elongation portion 12b extends beyond the maximum circumference level of the operating envelope 10. That is, the headgear 100 can be configured to achieve a greater circumference than the intended maximum head circumference to allow the headgear 100 to be conveniently placed onto a user having the maximum head circumference of the operating envelope 10 of the headgear 100. In use, especially with users having head sizes on the smaller end of the operating envelope 10, the headgear 100 may not be elongated to a maximum circumference

during donning and, in some cases, may not be elongated beyond the maximum circumference level of the operating envelope 10.

[0585] After the headgear 100 has been elongated to the maximum circumference, to a circumference greater than the operating envelope 10 or, in use, to some other circumference sufficient to allow donning onto the user, the illustrated force-deflection curve drops steeply (initial retraction portion 14a) and then transitions to a relatively shallow portion, in which the circumference reduces substantially with a relatively small change in force. This shallow portion of the curve can be referred to as a retraction portion 14b and is partially illustrated by Figure 4.2. Preferably, in the retraction portion 14b, the headgear 100 reduces in circumference at a relatively low force level until the headgear 100 reaches an appropriate circumference to fit the user's head. The headgear 100 can be positioned on the user's head at this low force level (the left end of the retraction portion 14b or "fit point 16") until therapy is initiated or until another force attempting to elongate the headgear 100 is applied.

[0586] Advantageously, this relatively low force level allows the headgear 100 to be comfortable for the user. In some configurations, the retraction portion 14b of the force-deflection curve is at or below the minimum force level of the operating envelope 10. Thus, in such an arrangement, the retraction force of the headgear 100 can be lower than that necessary or desirable to resist minimum forces induced in the headgear 100 by the therapy (e.g., a low CPAP level). Accordingly, even at low therapy levels, the headgear 100 can be configured to produce only enough retention force to resist the therapy-induced forces because the minimum force level of the operating envelope 10 is above the retraction portion 14b of the force-deflection curve. In some configurations, as described below, the retraction portion 14b of the force deflection curve could fall within the operating envelope 10. Such an arrangement can be referred to as exhibiting "composite" behavior. However, preferably, the retraction portion 14b of a composite-behavior headgear force-deflection curve remains below the maximum force level of the operating envelope 10.

[0587] When therapy is commenced, or another elongating force is applied to the headgear 100, the force deflection curve rises relatively steeply from the fit point 16 to a point within the operating envelope 10 at which the retention force of the headgear 100

balances with the force induced by the therapy and/or other forces (e.g., hose pull forces) attempting to elongate the headgear 100. Such a point can be referred to as a balanced fit point 18. The force-deflection curve between the fit point 16 and the balanced fit point 18 can have substantially the same slope as the initial elongation portion 12a. The actual location of the balanced fit point 18 can be anywhere within the operating envelope 10 depending on the actual force induced by the therapy and the actual head size of the user. In any particular case, the force in the headgear 100, which is applied over an area related to headgear size as a pressure to the user, is substantially only the force necessaiy to counteract the forces induced by the therapy. Thus, in at least some configurations, the pressure applied to the user can be minimized for any particular headgear size and shape for the particular level of therapy utilized. The elongation portion 12b of the force-deflection curve can be spaced above the maximum force level of the operating envelope 10 to provide a reserve in which additional forces (e.g., hose pull forces) can be applied without elongation of the headgear 100. Once sufficient force is applied to the headgear 100 to reach the elongation portion 12b of the force-deflection curve, elongation of the headgear 100 can occur. However, the headgear 100 can be designed or configured to have a force-deflection curve that accommodates expected or usual therapy forces and hose pull forces or any combination thereof.

[0588] As described above, in at least some configurations, the user can manipulate the headgear 100 to cause a micro-adjustment of the perimeter length. Advantageously, such an arrangement allows the user to, for example, address leaks or tighten or loosen the headgear 100 (reduce the perimeter length) to a desired level by simply grasping the mask or other interface and moving (e.g., wiggling) the mask or other interface relative to the user's face and a rear portion of the headgear 100, as illustrated in Figure 4.3. As indicated by the arrows in Figure 4.3, the mask or other interface can be moved or adjusted in a plurality of directions, including toward and away from the user's face or in a rotational manner (e.g., about a vertical or horizontal/lateral axis). Movement toward the face can result in a reduction of the perimeter length or tightening of the headgear 100 to, for example, achieve a fit that is toward the tight end of the spectrum of an acceptable or desirable fit, which can be referred to as a "tight fit." Movement away from the face can

result in elongation of the perimeter length or loosening of the headgear 100 to, for example, achieve a fit that is toward the loose end of the spectrum of an acceptable or desirable fit, which can be referred to as a "loose fit." Rotational movement about a vertical axis can cause one side of the headgear 100 to tighten and the other side to remain the same or loosen. Rotation about a horizontal or lateral axis can cause one of an upper or lower portion of the headgear 100 to tighten and the other of the upper or lower portion to loosen.

[0589] As described above, it is not necessary in all configurations that the retraction portion 14b of the force-deflection curve be located below a minimum force level of the operating envelope 10. The headgear 100 can be designed or configured to position the retraction portion 14b of the force-deflection curve within the operating envelope 10 and at a level that provides a sufficient degree of comfort to the user. In some cases, the user may desire that the headgear 100 apply some degree of force in order to provide the user with some tactile feedback that provides a feeling of comfort that the headgear 100 is securely holding the interface in place. Such force applied by the headgear 100 may, for some users, fall within the operating envelope 10 of the particular therapy. Thus, with such an arrangement, under at least some conditions, the retraction force of the headgear 100 may be sufficient to resist therapy forces at least as some lower therapy levels and/or certain larger head sizes.

[0590] Figure 5 illustrates a graph containing an example "composite" force-deflection curve. For the sake of illustration, an example of an elastic headgear force-deflection curve is illustrated in the graph in addition to the composite force-deflection curve. The composite force-deflection curve can be substantially similar or identical to the force-deflection curve described above in connection with Figure 4 except the composite force-deflection curve positions the retraction portion 14b within the operating envelope. The retraction portion 14b of the force-deflection curve divides the operating envelope into a lower portion 20 and an upper portion 22. The headgear can absorb forces in the lower portion 20 below the retraction portion 14b of the force-deflection curve utilizing the retraction force of the headgear, which can be provided by one or more elastic elements. Forces in the upper portion 22 above the retraction portion 14b of the force-deflection curve can be absorbed by the retention force of the headgear, which can be provided by one or more retention elements (e.g., locks), in a manner similar to that described above in connection with Figure 4.

[0591] An example of an elastic headgear force curve 15 is illustrated overlying the retraction portion 14 of the force-deflection curve. The elastic headgear force curve 15 includes upper and lower curve portions separated by a relatively small vertical distance representing the internal frictional losses or hysteresis within the headgear. The force necessary to elongate the headgear is slightly greater than the retraction force of the headgear. An elastic headgear exhibiting the illustrated elastic force-deflection curve 15 can only accommodate applied therapy or other forces below the force-deflection curve 15. Applied forces above the force-deflection curve 15 will result in elongation of the elastic headgear. Thus, the force-deflection curve 15 of an elastic headgear must be positioned above the maximum force level of the operating envelope to avoid undesired elongation under at least some conditions (e.g., high therapy forces or small head size). The level of pressure applied to a user as a result of such a force-deflection curve 15 is likely to be uncomfortable under at least some conditions (e.g., low therapy forces or large head size).

[0592] In contrast, the composite force-deflection curve (or the balanced fit force-deflection curve shown and described in connection with Figure 4) exhibits a relatively large vertical distance between the upper portion 12b of the curve and the lower portion 14b of the curve. At least a portion of the operating envelope falls within the vertical space between the upper portion 12b of the curve and the lower portion 14b of the curve. Accordingly, a headgear exhibiting such a force-deflection curve can resist relatively high forces while applying a relatively low force or pressure to the user in the absence of therapy or other elongation forces. In addition, once therapy is commenced, the force or pressure applied to the user remains the same (if below the retraction portion 14b of the force-deflection curve in a composite arrangement) or increases only to substantially the level needed to resist the applied force.

[0593] The forces applied to the headgear by the interface typically relate to a projected area of the seal of the interface. Smaller interfaces, such as nasal pillows or nasal masks, seal around a smaller area and, thus, produce a smaller force relative to larger interfaces, such as full face masks. Some interfaces (e.g., nasal cannula) may not create a seal with the face of the user and, thus, the forces applied to the headgear may relate primarily to the weight of the interface. Figure 6 illustrates a graph of the force required to keep the interface in sealed contact with the user's face as it relates to the projected area of the seal. In general, the greater the projected area of the seal, the greater the force required to keep the interface in sealed contact with the user's face and, thus, the greater force that need to be resisted by the headgear. Such force can be referred to as a retention force of the headgear.

[0594] The graph of Figure 6 includes two lines 24, 26 defining upper and lower limits of a range of acceptable retention forces for interfaces having different projected seal areas. The two lines 24, 26 are vertically spaced from one another and extend upwardly from left to right with a moderate slope. The lower line 24 can represent a minimum force necessary or desirable to maintain a seal with the user's face. The upper line 26 can represent a maximum desirable force, which can be greater than necessary to maintain a seal, but preferably is low enough to maintain user comfort or avoid excessive seal collapse. The space between the lower line 24 and the upper line 26 can represent a usable or target range 28 of adjustment to accommodate user preference, with the lower line 24 representing a usable or acceptable loose fit and the upper line 26 representing a usable or acceptable tight fit. The lower line 24 can include one or more relatively short, steep upward pitched sections that represent a transition between types of interfaces, such as nasal pillows to nasal mask and nasal mask to full face mask. The upper line 26 is illustrated as straight, but could include steep pitched sections corresponding to those of the lower line 24 to maintain a constant target adjustment range.

[0595] The graph of Figure 6 also includes a flat or horizontal line 30 at a force level above the target range or target zone 28. This line 30 represents a force that will or is likely to cause skin damage to a user over a relatively short period of continued use of a particular headgear. This line 30 can be referred to as the maximum force line 30. The actual force value may vary depending on characteristics of the particular headgear, such as contact area or type of material. A vertical distance between the target zone 28 and the maximum force line 30 represents a margin of error 32 for adjustment of a headgear force. As illustrated, the margin for error 32 is reduced for an interface having a larger projected seal area, such as a full face mask, in comparison with an interface having a smaller projected seal area, such as nasal pillows or a nasal mask. Accordingly, especially with larger projected seal area interfaces, it is desirable that a headgear be easily or conveniently capable of adjustment to within or close to the target zone 28. Conventional inelastic headgear incorporates relatively coarse adjustments, such as one or more adjustable loops that are secured with hook-and-loop fasteners. Such headgear can be difficult to adjust to within the target zone 28, especially in environments in which the wearer of the headgear is not the person making the adjustments, which often occurs in hospital settings, for example.

[0596] Figure 7 illustrates a three-dimensional graph of a relationship between headgear force, projected seal area and circumference. The graph of Figure 7 is a combination of the graph of Figure 6 and the graph of Figure 4. The graph of Figure 7 illustrates the minimum force 24 for creating a seal between the interface and the user's face (the lower line 24 of the target zone 28 of Figure 6). Below the minimum force line 24, the headgear force can be insufficient to create or maintain a seal. The graph of Figure 7 also illustrates the maximum force line 30 above which skin damage is likely to occur. In between the minimum force line 24 and the maximum force line 30 is a safe operating envelope for the headgear force. The upper line of the target range is omitted for clarity.

[0597] The graph of Figure 7 also illustrates a force-deflection curve of an example headgear. The force-deflection curve can be located within any plane along the projected seal area axis to illustrate design criteria for a headgear intended for use with a particular type of interface having a particular projected seal area. A headgear could also be designed taking into consideration the headgear forces and circumferences along a segment or an entirety of the projected seal area axis to design a headgear that will operate with multiple types of interfaces or that is universal for all types of interfaces (at least with respect to a particular therapy). In some configurations, as illustrated by the force-deflection curve in Figure 7, the elongation portion 12 of the force-deflection curve can be located above the maximum force line 30.

[0598] In at least some configurations, headgear exhibiting a balanced fit or composite force-deflection curve, as described above, advantageously provides a retention force that falls within the safe operating envelope and, preferably, within the target zone. In at least some configurations, such headgear automatically adjusts to a suitable retention force within the safe operating envelope and, preferably, within the target zone. Thus, under-tightening or over-tightening by the user or by another can be reduced or eliminated.

[0599] As described above, the example headgear system performs several functions in the process of fitting, using and removing an interface or mask system. For fitment, the headgear system extends in length to enable it to be placed over a user's head. The headgear system retracts in length during the "fitment" process and provides sufficient force to the mask system such that the user feels that the mask system is secure. Once aimay pressure is applied, the headgear system "transforms" in performance from an elastic or stretchy behaviour to one of inelastic behaviour. The headgear system also provides for micro-adjustment to tighten or loosen the mask based on the user's preference during use. For removal, the headgear system extends in length to enable it to be removed over a user's head. The combination of one or more, including all, of these features provides a mask system that requires minimal user interaction to fit and remove. This removes the potential for misuse and may help with improved usability of the mask system. The example headgear system can also mitigate the effects of excess pressure on the skin by reducing the probability, or even the possibility, of over-tightening of the head gear. The example headgear system can improve the overall compliance with the therapy. An additional feature to this is one which has a high degree of positional location and stability. This is both in terms of the activities of removal and refitting of the mask and during its use. Disclosed herein are one or more concepts for achieving a repeatable and stable positioning of the headgear and associated interface assembly on a patient or user's head. Also disclosed herein are one or more concepts for achieving a headgear system that supports transformational behaviour by providing portions that can selectively be made either elastic or inelastic and portions that provide an inelastic behaviour.

[0600] Figures 8A and 8B illustrate the force profiles of constant pressure therapy and variable pressure therapy, respectively, along with associated elongation behaviour of elastic and inelastic headgear systems in graphical form for a full face mask. Figure 8A includes two graphs of force and elongation, respectively, induced in the headgear over time with application of constant pressure therapy, such as CPAP at 10 cm of H20. The upper

graph illustrates the force that is induced in the headgear by the combination of the applied gas pressure and the mask enclosure area or, simply, the mask area. Despite the constant delivery pressure of the therapy, the force curve includes small oscillations that result from the user breathing and causing pressure changes within the mask. The lower graph illustrates the resulting elongation or movement in the headgear system and, thus, the mask body as the result of the forces applied. There are two elongation lines 34, 36 shown in the lower, elongation graph. The first line 34 illustrates the elongation behavior of a state-of-the-art elastic headgear, which elongates in response to the application of force. In the illustrated example, the elastic headgear elongates about 8 mm at the CPAP pressure compared to the length without CPAP pressure. The second line36 illustrates the elongation behavior of the state-of-the-art inelastic headgear. As illustrated, the inelastic headgear exhibits veiy little elongation in response to applied force.

[0601] Figure 8B similarly includes a graph of force and elongation, respectively, induced in the headgear over time with the application of oscillatory or variable pressure therapy, such as NIV or Bi-level PAP. For example, the illustrated therapy varies between a pressure of about 5 cm of H20 (e.g., expiratoiy positive airway pressure - EPAP) and about 12 cm of H20 (e.g., inspiratory positive airway pressure - IPAP). The upper graph illustrates the force that is induced in the headgear by the combination of the applied gas pressure and the mask enclosure area or, simply, the mask area. The lower graph illustrates the resulting elongation or movement in the headgear system and, thus, the mask body as the result of the forces applied. There are two elongation lines 34, 36 shown in the elongation graph. The first line 34, illustrates the elongation behavior of a state-of-the-art elastic headgear, which elongates and contracts along with increases and reductions in applied force, hi the illustrated example, the elastic headgear elongates moves between about 4 mm and about 12 mm (at low pressure and high pressure, respectively) in response to the variable force curve compared to the length without CPAP pressure. Typical practice to reduce or prevent this movement is to over tighten the headgear system such that the force required elongate the headgear is greater than which is being produced by the combination of mask area and ventilation pressure. The application of this practice frequently leads to skin damage and the resulting wound care practices. The second line 36 illustrates the elongation behavior of the state-of-the-art inelastic headgear, which, as in Figure 8A, exhibits very little elongation, but has the above-described limitations and drawbacks.

[0602] As shown in the example, state-of-the-art headgear systems when used with a full face mask, and which have not been over tightened, will elongate in length such that the mask body would move about 8 mm to about 12 mm during the change from peak inspiratoiy pressure to end expiratory pressure for NIV or IPAP to EPAP for bi-level ventilation. In at least some configurations, the present directional locking headgear systems exhibit behavior similar to the inelastic headgear in response to application of force in a direction tending to elongate the headgear. However, such configurations of the directional locking headgear systems exhibit one or more benefits of elastic headgear (e.g., automatic size adjustment or automatic fit) without the drawbacks associated with inelastic headgear (e.g., time-consuming and difficult adjustment). In at least some configurations, a headgear system incorporating a directional locking arrangement provides headgear elongation or mask movement of less than about 4 mm in response to applied force during therapy compared to a condition as applied to the user but without system pressure. In some configurations, a headgear system incorporating a directional locking arrangement provides headgear elongation or mask movement of less than about 4 mm between a high or maximum therapy pressure condition and a low or minimum therapy pressure condition (e.g., peak inspiratory pressure and end expiratory pressure for NIV).

[0603] The functional behaviour of the example headgear system involves the various headgear elements having elongation properties in design-specific locations, so that the elasticated or stretching behaviour can be switched on and off on demand, preferably with one or more of the directional locks and/or directional friction mechanisms disclosed herein. This can involve various features of the headgear being configured to deliver specific performance attributes in specific locations. With patient interfaces used in respiratory applications, the location of these features can depend on the interface type and the number of retention planes that are desired. A retention plane can be defined as a plane or planes through which forces that are generated in the interface assembly are resolved.

[0604] For example, Figure 9 illustrates a nasal interface, such as a nasal pillows mask, nasal mask or nasal cannula having a single retention plane. A first line extends

between a mounting point on a first side of the nasal interface and a mounting point on the first side of a rear portion of the headgear. A second line extends between a mounting point on a second side of the nasal interface and a mounting point on the second side of the rear portion of the headgear. The first line and the second line cooperate to define the single retention plane. The retention plane can extend through or near a center of the nasal interface, which can be a geometric center or vertical center, for example. In some configurations, the retention plane can be off-center, such as in configurations in which it may be desirable to apply a bias force (e.g., upper or lower bias) to the nasal interface. The retention plane can extend generally from a location at or near (e.g., somewhat below) the underside of the user's nose to a location close to but somewhat above the user's ear. Such an arrangement may cause the retention plane to have an upward tilt in a front-to-back direction.

[0605] Figure 10 illustrates a nasal interface, such as a nasal pillows mask, nasal mask or nasal cannula having multiple (e.g., two) retention planes. As described with respect to Figure 9, each retention plane is defined by lines on each side of the interface assembly, which lines extend between points on the nasal interface and a rear portion of the headgear. In the arrangement of Figure 10, the retention planes are offset from one another to define an angle in a front-to-back direction or from a side view. In the illustrated arrangement, a first retention plane extends through a relatively upper point on the nasal interface and a second retention plane extends through a relatively lower point on the nasal interface. The first and second retention planes can extend through a single point on the rear portion of the headgear (or very near one another) or can be spaced apart on the rear portion of the headgear, with the planes intersecting one another (crossing one another) between the nasal interface and the rear portion of the headgear or can be spaced apart between the nasal interface and the rear portion of the headgear. In the illustrated arrangement, the first retention plane is positioned at or near an upper edge of the inlet, breathing tube connector or gases conduit connector and the second retention plane is positioned at or near a lower edge of the inlet, breathing tube or gases conduit. In some configurations, the retention plane(s) can extend along a physical portion of the headgear or interface assembly. However, in other configurations, the retention plane(s) may not extend along a physical portion of the headgear or interface

assembly. That is, for example, the retention plane(s) may not be aligned with a strap of the headgear.

[0606] Other types of interface assemblies can similarly utilize retention planes between the interface and a rear portion of the headgear. For example, Figure 11 illustrates a full face mask having two retention planes. The illustrated full face mask includes an upwardly-extending frame portion or T-piece, which extends from a lower portion of the mask toward or to the user's forehead. In the illustrated arrangement, a first or upper retention plane extends between the T-piece and an upper location on a rear portion of the headgear. The upper retention plane can extend above the user's eyes and ears. The upper retention plane can be generally horizontal, but can be tilted somewhat in a front-to-back direction. For example, the upper retention plane can be tilted somewhat downward in a front-to-back direction to pass between the user's forehead and a center or rearward-most point on the back of the user's head. A second or lower retention plane extends between a base portion of the mask and a lower location on the rear portion of the headgear. The lower retention plane can extend between a point at about the user's mouth to a point below the user's ear. The lower retention plane can be generally horizontal, but can be tilted somewhat in a front-to-back direction. For example, the lower retention plane can be tilted somewhat upward in a front-to-back direction. The upper retention plane can extend along an upper strap of the headgear. The lower retention plane can extend generally along a lower strap of the headgear; however, the lower strap can be curved to accommodate the user's ear such that the lower retention plane overlies end portions of the lower strap, but does not overlie at least an intermediate portion of the lower strap. In other configurations, one or both of the upper and lower retention planes can partially or fully overlie an associated strap, can be partially or fully spaced from an associated strap or any combination of the two.

[0607] Figure 12 illustrates a nasal mask having two retention planes. Similar to the full face mask of Figure 11, the illustrated nasal mask includes an upwardly-extending frame portion or T-piece, which extends from a lower portion of the mask toward or to the user's forehead. In the illustrated arrangement, a first or upper retention plane extends between the T-piece and an upper location on a rear portion of the headgear. The upper retention plane can extend above the user's eyes and ears. The upper retention plane can be

generally horizontal, but can be tilted somewhat in a front-to-back direction. For example, the upper retention plane can be tilted somewhat downward in a front-to-back direction to pass between the user's forehead and a center or rearward-most point on the back of the user's head. A second or lower retention plane extends between a base portion of the mask and a lower location on the rear portion of the headgear. The lower retention plane can extend between a point at about the user's nose to a point aligned with or below the user's ear. The lower retention plane can be generally horizontal, but can be tilted somewhat in a front-to-back direction. For example, the lower retention plane can be tilted somewhat downward in a front-to-back direction. The upper retention plane can extend along an upper strap of the headgear. The lower retention plane can extend between forward and rearward end portions of a lower strap of the headgear. The illustrated lower strap can be curved to accommodate the user's ear such that the lower retention plane does not overlie an intermediate portion of the lower strap. In either of the interface assemblies of Figures 11 and 12, the lower retention plane can pass through an inlet, breathing tube connector or gases conduit connector of the interface, such as through or near a center of the inlet or connector.

[0608] Figure 13 illustrates an alternate arrangement that is applicable to a either a full face mask or a nasal mask in which there are two retention planes that converge to a single point within the head gear system. The retention planes can be vertically spaced from one another on the interface to provide some degree of stability to the interface. For example, in a full face mask, an upper retention plane can pass through or above the underside of the nose of the user and a lower retention plane can pass near or below the mouth of the user. In a nasal mask, the upper retention plane can pass above the underside of the nose of the user and the lower retention plane can pass below the underside of the nose of the user. The retention planes can intersect at a point generally above and/or forward of the ear of the user. The portions of the interface assembly coupling the mask to a rear portion of the headgear can be separate or interconnected, such that a single adjustment can at least potentially alter a length of both upper and lower portions. The length ratio of the upper and lower portions can be easily adjusted by moving the point of the interconnected portions that is located at the headgear connection point. The illustrated full face mask does not include a forehead rest or "T-piece." However, in some configurations, a T-piece could be provided. If desired,

additional headgear element(s) or strap(s) could couple a rear portion of the headgear to the T-piece of the mask.

[0609] Figure 13.1 is a chart that identifies a number of general categories of headgear types on the basis of the number and/or relative positioning of retention planes. The chart also identifies a number of interface types and provides an indication of the desirability or practicality of the resulting combinations of headgear type and interface type. Because of the automatic fit of at least some of the headgear assemblies disclosed herein, it is possible that a single headgear type can be utilized with multiple types of interfaces. Examples of possible combinations are described with reference to Figure 13.1. The headgear types are listed from top to bottom in order of those that provide relatively less stability to those that provide relatively more stability, at least in certain configurations, such as those in which little to no external source of resistance to rotation of the interface is provided. The headgear types listed in the chart of Figure 13.1 is not exclusive. Other headgear types may be used with the concepts disclosed herein, including modifications and hybrids of the illustrated headgear types.

[0610] In general, more stable headgear configurations can be universal or can provide at least an acceptable level of support to many or all interface types, or at least those interface types illustrated. In contrast, less stable headgear configurations may not be capable of providing a desirable or acceptable level of support to all interface types, at least without specific provisions to increase the stability of such inherently less stable configurations. In general, larger interfaces require or benefit from headgear that provides greater stability. It is often desirable or sometimes necessary to provide at least two retention planes for larger interfaces, such as full face masks. It can be advantageous for the two retention planes to be separated from one another in a vertical or height direction of the interface at the interface (e.g., at the points of attachment to the interface). In general, for a given headgear arrangement, the further the separation of the retention planes at the interface, the more stable the configuration. In some configurations, it can be advantageous for at least one of the retention planes to include an upward vector component.

[0611] One example headgear type provides a single retention plane. An example of such an arrangement is discussed herein with reference to Figure 9. In general, single

retention plane headgear can be impractical for use with full face interface types because the single retention plane headgear does not provide a desirable level of stability to the mask. Thus, the headgear may be able to secure the mask in place and maintain a seal, but the mask may be permitted to move and break the seal with relative ease or the interface assembly, although operable, may not provide a secure feeling to the user. In some cases, single retention plane headgear may not provide an acceptable level of stability to the mask. However, it is possible that some configurations of a single retention plane headgear could be suitable for use with a full face mask. For example, a single retention plane headgear utilizing rigid materials and/or configurations (e.g., shapes) could be suitable for use with a full face mask by providing resistance to rotation of the mask about a lateral axis. In addition, a single retention plane headgear can be suitable for use with a full face mask with careful location of the single retention plane relative to the full face mask, as illustrated in and described below with respect to Figure 13.2. A single retention plane interface may be suitable or practical for use with nasal interfaces, such as nasal masks, nasal pillows or prongs and cannula.

[0612] Figure 13.2 illustrated a single retention plane interface assembly comprising a headgear assembly and an interface, which is in the form of a full face mask. The illustrated mask omits a forehead rest or T-piece; however, in other configurations a T-piece could be provided. The headgear assembly includes a headgear rear portion and a headgear length or perimeter adjusting portion that allows adjustment of a position of the mask relative to the headgear rear portion. The single retention plane can extend from the mask to the headgear rear portion at a location above the user's ear, for example.

[0613] Forces acting on the mask can be summarized as a blow-off force created by pressure within the mask acting on the sealed area of the user's face and attempting to move the mask away from the user's face, a headgear force acting on the mask to resist the blow-off force, a force applied by the user's face along the contact area between the mask and the user's face, and a gravity force that acts on the mass of the mask and CPAP hose. The force applied by the user's face can be summarized by an upper force and a lower force. The upper force can be a force located at or near the nasal bridge of the user's nose ("nasal bridge force"), which can be generally the highest point or region of contact in a vertical direction.

The lower force can be a force located at or near the chin of the user ("chin force"), which can be generally the lowest point or region of contact in a vertical direction.

[0614] The distributed gravity force can be summarized as a single point force ("gravity force") acting on the mask and CPAP hose at a center of gravity, which may be determined by the particular size and shape of the mask. In some configurations, the single retention plane extends between or passes through a point between the chin force and the blow-off force in a vertical direction.

[0615] The distributed blow-off force can be summarized as a single point force ("blow-off force") acting on the mask at a particular location, which may be determined by the particular size and shape of the mask and/or the specific shape of the user's face. The blow-off force can be located generally in a lower half of the mask height, such as at or near a geometric center of the mask. Assuming a generally triangular mask, the blow-off force can be located at approximately 1/3 of the height from the bottom of the mask. In some configurations, the single retention plane extends between or passes through a point between the chin force and the blow-off force in a vertical direction. Advantageously, such an arrangement can provide a desirable level of stability for a full face mask with a single retention plane. However, this arrangement can be applied to a multi-retention plane arrangement, as well, with the additional retention plane(s) providing additional stability.

[0616] The nasal bridge area can be a sensitive anatomical area and it can be desirable to avoid excessive force or pressure in this area. Thus, if the nasal bridge force is zero or minimal, the headgear force can be the only force countering the blow-off force. If the headgear force passes through a point vertically higher than the blow-off force, the nasal bridge force will be increased, which is generally undesirable. If the headgear force is too low, or too close to the chin force, the headgear force may not be able to counter the blow-off force or may provide an undesirably low level of counteraction of the blow-off force such that the sealing performance of the interface assembly is compromised. As described herein, preferably the retention plane comprises directional lock arrangement that provides an appropriate resistance to elongation of the headgear in response to the blow-off force. In combination with positioning of the retention plane as described herein, the resultant interface or headgear assembly can provide a suitable level of stability for a full face mask with a single retention plane type headgear. As with other headgear assemblies described herein, proper stability can be achieved without over-tightening of the headgear, which often occurs with prior art headgear arrangements.

[0617] Another example headgear type provides two retention planes that converge at a forward location (i.e., toward or at the interface). As used in herein in connection with Figure 13.1, the term "converge" is intended to describe retention planes that lack substantial separation from one another at the interface or attachment locations. It is possible that the retention planes may meet at a single attacliment point; however, convergent headgear types may also include those in which the retention planes are attached next to or close to one another. A two retention plane, forward converge headgear type can be suitable or at least somewhat practical for use with a full face headgear, because the additional retention plane may provide sufficient additional stability relative to a single retention plane headgear. As described with respect to single retention plane headgear types, the two retention plane, forward converge headgear type can employ rotation-resisting materials and/or configurations to provide improved performance with full face masks. A two retention plane, forward converge headgear type may be suitable or practical for use with nasal interfaces, such as nasal masks, nasal pillows or prongs and cannula.

[0618] Yet another example headgear type provides two retention planes that converge at a rearward location (i.e., away from the interface, such as at a rear portion of the headgear). A two retention plane, rearward converge headgear type can provide a sufficient level of stability to be suitable or practical for use with full face masks and with nasal masks. Examples of such a headgear type are shown and described herein in connection with Figures 10 and 13 with a nasal interface and a full face interface, respectively. A two retention plane, rearward converge headgear type may be less practical for use with pillows or prongs interface types because such interface types typically have a relatively small vertical or height dimension. The small height of pillows and prongs interface types can limit the ability to space the attachment locations of the retention planes on the interface and provide triangulation of the retention planes, at least without increasing the height dimension above what is required, which can be undesirable because pillows and prongs are often elected by users precisely due to their relatively small height dimension. A two retention plane,

rearward converge headgear type may be impractical for use with cannula because it is not necessary to create a sealing force for a cannula. Thus, a two retention plane headgear type can be excessive for use with cannula. In addition, a two retention, rearward converge headgear type can be impractical for use with cannula for the same reasons as pillows and prongs. Cannula generally have an even smaller height dimension than pillows and prongs. However, in at least some configurations or under some circumstances, it may be practical or even desirable to use a two retention plane, rearward converge headgear type with pillows, prongs or cannula.

WHAT IS CLAIMED IS:

1. A headgear assembly for a respiratory interface, comprising:

a plastic core; and

a textile casing;

wherein the plastic core and the textile casing are formed as an integral structure by the application of a molten plastic material into the textile casing.

2. The headgear assembly of Claim 1, wherein the textile casing comprises a first portion that covers an inwardly-facing surface of the headgear.

3. The headgear assembly of Claim 2, wherein the textile casing comprises a second portion that covers an outwardly-facing surface of the headgear.

4. The headgear assembly of Claim 3, wherein the first portion and the second portion of the textile casing meet at first and second edges.

5. The headgear assembly of Claim 4, wherein the first portion and the second portion are not connected to one another at the first and second edges.

6. The headgear assembly of any one of Claims 1-5, wherein the textile casing comprises one or more retainer holes configured to engage a retaining pin of a moulding tool.

7. The headgear assembly of any one of Claims 1-6, further comprising at least one flexible joint that permits the headgear to bend and/or fold.

8. The headgear assembly of Claim 7, wherein the at least one flexible joint comprises a gap between portions of the plastic core and wherein the textile casing extends within the gap to connect the portion of the plastic core.

9. The headgear assembly of Claim 8, further comprising at least one bridge portion extending within the flexible joint between the portions of the plastic core.

10. The headgear assembly of Claim 9, wherein the at least one bridge portion is unitarily formed with the portions of the plastic core.

11. A headgear assembly for supporting a respiratory interface on a user, comprising:

a substantially inelastic rear portion;

a substantially inelastic front portion;

a first elastic side portion on a first side of the headgear assembly;

a second elastic side portion of a second side of the headgear assembly;

at least one filament that extends through or along the first and second elastic side portions, the at least one filament coupled to one of the inelastic rear portion and the inelastic front portion;

at least one restriction arrangement;

wherein the at least one filament passes through the at least one restriction arrangement, and wherein the at least one restriction arrangement is configured to selectively engage the at least one filament to resist movement of the at least one filament relative to the at least one restriction arrangement.

12. The headgear assembly of Claim 11, wherein the at least one restriction arrangement is configured to provide a first resistance force to movement or attempted movement of the at least one filament in a direction that allows the inelastic rear portion and the inelastic front portion to move away from one another.

13. The headgear assembly of Claim 12, wherein the at least one restriction arrangement is configured to provide a second resistance force to movement or attempted movement of the at least one filament in a direction that allows the inelastic rear portion and the inelastic front portion to move toward one another, wherein the second resistance force is less than the first resistance force.

14. The headgear assembly of any one of Claims 1 1-13, wherein the inelastic front portion is rigid.

15. The headgear assembly of Claim 14, wherein the inelastic front portion is configured to be connected to a respiratory interface.

16. The headgear assembly of either one of Claims 14 or 15, wherein the inelastic front portion defines at least one collection passage that accommodates a portion of the at least one filament.

17. The headgear assembly of any one of Claims 11 -16, wherein each of the first and second elastic side portions comprises an end cap having an opening through which the at least one filament passes.

18. The headgear assembly of Claim 17, wherein the end cap is overmolded onto the respective one of the first and second elastic side portions.

19. The headgear assembly of either one of Claims 17 or 18, wherein the end cap is coupled to the inelastic front portion.

20. The headgear assembly of any one of Claims 11-19, wherein the inelastic rear portion, the inelastic front portion, the first elastic side portion and the second elastic side portion define a closed loop perimeter.

21. A headgear assembly for supporting a respiratory interface on a user, comprising:

a rear headgear portion configured to contact the rearward and/or upper portions of a head of the user, the rear headgear portion comprising a plastic core and a textile casing, wherein the plastic core and the textile casing are formed as an integral structure by the application of a molten plastic material into the textile casing, each side of the rear headgear portion comprising a mounting portion configured to be located forwardly of an ear of the user in use;

an interface connection arrangement provided to the mounting portion on each side of the headgear assembly, each interface connection arrangement configured to be directly or indirectly coupled to the respiratory interface, each interface connection arrangement comprising:

at least one length adjusting arrangement, each length adjusting arrangement comprising an elastic element, a core member and a restriction arrangement, wherein the core member is associated with the elastic element and is fixed relative to one end of the elastic element, wherein the core member passes through the restriction arrangement, and wherein the restriction arrangement is configured to selectively engage the core member to resist movement of the core member relative to the restriction arrangement.

22. The headgear assembly of Claim 21, wherein the rear headgear portion has no structure passing below the ear of the user that would inhibit removal of the rear headgear portion in an upward direction.

23. The headgear assembly of either of Claims 21 or 22, wherein each of the interface connection arrangements comprises at least a first length adjusting arrangement and a second length adjusting arrangement.

24. The headgear assembly of Claim 23, wherein a location of at least one of the first length adjusting arrangement and the second length adjusting arrangement on the mounting portion is adjustable.

25. The headgear assembly of Claim 24, wherein each of the mounting portions comprises a plurality of mounting locations for the first length adjusting arrangement and the second length adjusting arrangement, wherein the mounting locations are unitarily formed with the plastic core.

26. The headgear assembly of any one of Claims 21-25, further comprising at least one connector that is configured to connect the interface connection arrangements to the respiratory interface.

27. The headgear assembly of Claim 26, wherein the at least one connector comprises at least one collection passage configured to receive a portion of the core members.

28. The headgear assembly of any one of Claims 21-26, wherein the restriction arrangements are located on the rear headgear portion.

29. The headgear assembly of Claim 28, wherein the rear headgear portion defines at least one collection passage configured to receive a portion of the core members.

30. The headgear assembly of Claim 29, wherein the at least one collection passage is defined by the plastic core or between the plastic core and the textile casing.

31. The headgear assembly of Claim 28, wherein the restriction arrangements are located remotely from an end of the elastic element.

32. The headgear assembly of Claim 31, further comprising a guide for a portion of the core member between the end of the elastic element and the restriction arrangement.

33. The headgear assembly of any one of Claims 21-32, wherein the elastic element comprises an inelastic portion that restricts the elastic element to a maximum length.