Yoke for headgear

The apparatus, method, and system disclosed relates to a headgear assembly for a respiratory system for the delivery of respiratory therapy to a patient. The headgear comprises a yoke at least partially formed from an elastomeric material. The yoke is configured to be stretched under tension to attach the yoke to the headgear assembly.

BACKGROUND

Technical Field

The present disclosure generally relates to a respiratory system for the delivery of respiratory therapy to a patient. More particularly, the present disclosure relates to a yoke and a headgear assembly for use in a respiratory system.

Description of the Related Art

Respiratory masks are used to provide respiratory therapy to the airways of a person suffering from any of a number of respiratory illnesses or conditions. Such therapies may include but are not limited to continuous positive airway pressure (CPAP) therapy and non-invasive ventilation (NIV) therapy.

CPAP therapy can be used to treat obstructive sleep apnoea (OSA), a condition in which a patient's airway intermittently collapses during sleep, preventing the patient from breathing for a period of time. The cessation of breathing, or apnoea, results in the patient awakening. Repetitive and frequent apnoeas may result in the patient rarely achieving a full and restorative night's sleep.

CPAP therapy involves the delivery of a supply of continuous positive air pressure to the airway of the patient via a respiratory mask. The continuous positive pressure acts as a splint within the patient's airway, which secures the airway in an open position such that the patient's breathing and sleep are not interrupted.

Respiratory masks typically comprise a patient interface and a headgear, wherein the patient interface is configured to deliver the supply of continuous positive air pressure to the patient's airway via a cushion module, typically comprising a seal and frame assembly. The seal of the cushion module is configured to form an airtight seal in or around the patient's nose and/or mouth. Respiratory masks are available in a range of styles including full-face, nasal, direct nasal and oral masks, which create an airtight seal with the nose and/or mouth. The cushion module is held in place on the patient's face by the headgear. In order to maintain an airtight seal, the headgear should provide support to the patient interface such that it is held in a stable position relative to the patient's face during use. Such respiratory masks may also be used to deliver NIV and other therapies.

A yoke can be used to form a connection point between headgear and a cushion module, as shown inFIG.1. The yoke comprises a middle region located between two distal ends, each of which is typically attached to a free end of a front strap of the headgear. Headgear that comprises a yoke may be commonly referred to as closed loop headgear because the rear strap, front straps, and yoke of the headgear connect together to form a closed loop. The shape and width of the yoke determines the position of the ends of the yoke (and connection to front straps of the headgear) relative to the patient's face. If the yoke is too flat and wide, a moment arm may result, which reduces the stability of the cushion module on a patient's face, as shown inFIG.2. This problem may be exacerbated if a patient has a small head or a particularly narrow face. To overcome this problem, the yoke may be curved so that ends of the yoke are positioned closer to the patient's face, as shown inFIG.3. However, if the yoke is too curved, the ends may dig into the patient's cheeks, particularly when patient movement applies a rotational force to the yoke, as shown by dashed lines inFIG.3. The ends of the yoke may also dig into the patient's cheeks if the yoke ends have a large head or a substantially flat facial profile.

BRIEF SUMMARY

The systems 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.

In a first aspect, the invention provides a headgear assembly for a patient interface of a respiratory system, wherein the headgear comprises at least one strap to wrap around a user's head and a yoke connected to ends of the at least one strap, wherein the yoke is at least partially formed from an elastomeric material and wherein the yoke comprises at least one engagement member configured to attach to at least one retention member of the patient interface.

Preferably, the headgear comprises a rear strap connected to a pair of front straps, and wherein the yoke comprises a middle region located between two side regions that terminate at distal ends of the yoke, and wherein the distal ends of the yoke are configured to connect to free ends of the front straps.

Optionally, the yoke is fully formed from an elastomeric material.

In one form, the yoke comprises an upper surface, a lower surface, a front surface and a rear surface, and wherein a pair of stepped regions are provided on the upper surface and/or lower surface and/or rear surface of the yoke, each stepped region separating the middle region from each side region. Optionally, each stepped region comprises a transitional wall separating the middle region from the side regions, wherein each transitional wall forms an abutment surface configured to align with a corresponding abutment surface within a channel of a frame of a patient interface. Preferably, the abutment surfaces face toward each other and are angled outwardly toward distal ends of the yoke.

In one form, the side regions of the yoke are substantially rigid.

Optionally, each side region of the yoke comprises a washer box housing. In one form, the yoke comprises at least one collection chamber to receive one or more filaments from an automatically adjustable headgear system In one form, the yoke comprises distal ends and each distal end is connected to a headgear connector assembly comprising a washer box housing and a connector configured to connect to a front strap of the headgear.

In another form, the yoke comprises distal ends and each distal end is connected to a connector configured to connect to a front strap of the headgear.

Optionally, the yoke comprises substantially rounded edges.

In one form, the engagement member of the yoke comprises an aperture and the retention member comprises an arm configured to be received within the aperture.

In a second aspect, the invention provides a respiratory system comprising a patient interface comprising a mask assembly and a headgear assembly of any one of the preceding claims.

In one form, the mask assembly comprises a seal and frame assembly, and wherein the frame comprises a front surface and a rear surface, the front surface of the frame comprising a yoke channel extending laterally across the frame, the yoke channel being configured to receive the yoke of the headgear assembly.

Optionally, the yoke channel comprises an upper surface, a lower surface and a rear surface, wherein edges of the upper and lower surfaces each form a lip to define the front opening of the channel, and wherein the lips of the channel project toward each other so that the maximum distance between the lips is less than the maximum distance between the upper and lower surfaces of the channel.

In one form, the upper and lower surfaces of the channel are substantially concave along at least a portion of the length of the channel to provide the channel with a substantially C-shaped cross-section.

Preferably, the yoke channel comprises one or more retention members configured to retain the yoke within the channel.

Optionally, each retention feature comprises a tab that at least partially projects across the yoke channel and in front of the yoke when the yoke is located within the channel.

In one form, the mask assembly comprises a frame comprising a front surface and a rear surface, and wherein one or more retention members project from the front surface of the frame for engagement with one or more engagement members of the yoke.

Optionally, the mask assembly comprises a frame comprising a pair of arms projecting from left and right sides of the frame and the yoke comprises at least a pair of apertures, and wherein the distance between the apertures is less than the distance between the arms.

In one form, each yoke aperture provides access to a pocket or loop provided on the yoke and each arm is configured to pass through a respective yoke aperture to engage with the pocket or loop.

In a third aspect, the invention provides a method of attaching a yoke to a patient interface, the method comprising the steps of: engaging a first engagement member of the yoke, located at or near a first end of the yoke, with a first retention member located on a first side of the patient interface to hold the yoke to the patient interface at a first anchor point; pulling the yoke against the first anchor point until a second engagement member, located at or near a second end of the yoke, substantially aligns with a second retention member located on a second side of the patient interface; engaging the second retention member with the second engagement member as the yoke is held under tension; and releasing the yoke.

Also disclosed herein is a headgear assembly for a respiratory system. The headgear comprises a rear strap connected to a pair of front straps and a yoke that is at least partially formed from an elastomeric material. The yoke comprises a middle region, located between two side regions that terminate at distal ends of the yoke. The distal ends of the yoke are configured to connect to free ends of the front straps of the headgear.

In one form, the yoke is fully formed from an elastomeric material.

In one form, the yoke comprises an upper surface, a lower surface, a front surface and a rear surface. A pair of stepped regions may be provided on the upper surface and/or lower surface and/or rear surface of the yoke, each stepped region separating the middle region from a side region. In one form, each stepped region comprises a transitional wall separating the middle region from the side regions. The transitional wall forms an abutment surface configured to align with a corresponding abutment surface within a channel of a frame of a patient interface. Optionally, the abutment surfaces are angled toward each other in a direction from the front surface of the yoke to the rear surface.

In one form, the side regions of the yoke are substantially rigid.

Preferably, each side region of the yoke comprises a washer box housing. In this form, the yoke may comprise at least one collection chamber for receiving one or more filaments from an automatically adjustable headgear system In one form, each distal end of the yoke is connected to a headgear connector assembly comprising a washer box housing and a strap connector configured to connect to a front strap of the headgear. Alternatively, each distal end of the yoke is connected to a connector configured to connect to a front strap of the headgear.

In one form, the yoke may comprise substantially rounded edges. In this form, the yoke may be configured to engage with a frame having a yoke channel comprising a substantially C-shaped lateral cross-section.

Also disclosed herein is a respiratory system comprising a patient interface comprising a cushion module and a headgear assembly of the first aspect of the invention.

In one form, the cushion module comprises a seal and frame assembly. The frame may comprise a front surface and a rear surface, the front surface of the frame comprising a yoke channel extending laterally across the frame. The yoke channel may be configured to receive the yoke of the headgear assembly.

In one form, the yoke channel comprises an upper surface, a lower surface and a rear surface. Edges of the upper and lower surfaces may each form a lip to define the front opening of the channel. The lips of the channel may project toward each other so that the distance between the lips is less than the maximum distance between the upper and lower surfaces of the channel. Optionally, the upper and lower surfaces of the channel are substantially concave along at least a portion of the length of the channel to provide the channel with a substantially ‘C-shaped’ cross-section.

In one form, the yoke channel comprises a plurality of retention features configured to retain the yoke within the channel. Each retention feature may optionally comprise a tab that at least partially projects across the yoke channel and in front of the yoke when the yoke is located within the channel.

Also disclosed herein is a respiratory mask system comprising a frame as disclosed herein and a yoke as disclosed herein. The frame and yoke may comprise any feature or combination of features as described herein.

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.

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 “top”, “bottom”, “upper”, “lower”, “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.

DETAILED DESCRIPTION

Referring toFIGS.4to29, the invention relates to a respiratory mask system1000for the delivery of respiratory therapy to a patient. The mask system1000may comprise a patient interface2000and may also comprise a headgear assembly3000. The headgear assembly3000may comprise an elastomeric yoke100, by which to attach the headgear3000to the patient interface2000. The yoke100may be integrally formed with one or more straps of the headgear3000or the yoke may be detachably connected to one or more straps of the headgear.

In one form, the patient interface2000comprises a seal and frame assembly. The seal2100may comprise a front or distal surface2110and a rear surface or proximal surface2120. The rear surface2120of the seal2100may be configured to substantially seal against a patient's face during use. The seal2100may be configured to fit over a patient's mouth, nose, or both. In one form, the seal2100comprises nasal pillows that substantially seal around a patient's nares. In another form, the patient interface2000is a non-sealing interface such as a nasal cannula configured for high flow therapy.

The frame2200of the patient interface2000may be configured to attach the patient interface2000to the headgear3000. In one form, as shown inFIGS.1,4,5, and13, the frame2200comprises a body2210comprising a first surface or front surface2211and a substantially opposing second surface or rear surface2212. The frame2200may also comprise a gas inlet2220configured to attach to a gas conduit4000for delivering a gas to the patient via the patient interface1000. Optionally, the frame2200may also comprise one or more outlet vents2230. The elastomeric yoke100is typically configured to attach headgear3000to the frame2200.

In one form, the front surface2211of the frame comprises a yoke channel210configured to receive at least a portion of a yoke of a headgear assembly3000therein. The yoke channel210may extend across at least a portion of the front surface2211of the frame2200from left to right.

As shown inFIGS.4,5and10, the yoke channel210may be defined by a first wall211, forming an upper surface when in use, a second wall212, forming a lower surface that substantially opposes the first wall211, and a third wall213forming a rear surface that extends between the first and second walls211,212. The channel210may comprise two side regions210a,210b, each side region being located at an opposite end of the channel210, and a middle region210clocated substantially centrally between the two side regions210a,210b.

In one form, the height H2of the rear surface213of the channel210may be substantially defined by the distance between the upper and lower walls211,212of the channel210. At its middle region210c, the maximum height of the channel210may be less than the maximum height of the channel210at one or both side regions210a,210b. For example, the upper or lower surface211,212of the channel210may curve or angle toward the opposing surface212,211to form a peak substantially located at a central point along the length of the channel210.

In one form, as shown inFIG.10, the maximum height H1of the front opening214of the yoke channel210(i.e. the distance between opposing edges of the channel at the front surface of the frame) may be less than the maximum height H2between the upper and lower walls211,212within the interior of the yoke channel210. For example, the height H1of the channel opening214may be less than the height H2of the rear surface213of the channel210. In some forms, the maximum height H1of the channel opening214is less than the maximum height H2of the interior of the channel210in a middle region210cof the channel only.

In one form, the lower surface212of the yoke channel210may angle inwardly toward the rear surface213of the channel.

In one form, the upper surface211of the yoke channel may angle inwardly toward the rear surface213of the channel210.

In one form, the lower surface212of the yoke channel210may have a depth substantially defined by the distance between the rear surface213of the channel and a front edge212aof the lower surface212, where the lower surface212meets the front surface2211of the frame2200. In one form, the depth of the lower surface212of the yoke channel may be greater at areas adjacent to retention members220or abutment surfaces221(that hold the yoke within the yoke channel) than at lateral ends of the middle region210cof the channel or than at the side regions210a,210bor ends215a,215bof the channel210. In another form, the depth of the lower surface212may taper towards the ends of the yoke channel210.

In one form, the depth of the lower surface212tapers from a first depth adjacent to abutment surfaces221of the yoke channel210to a second depth at the lateral ends215a,215bof the yoke channel210.

The frame2200and yoke channel210may be substantially curved from left to right to conform to some extent to the curves around a patient's nose or mouth. Alternatively, or additionally, the frame2200and/or yoke channel210may slope or curve downwardly, from top to bottom, toward the seal or patient's face, or away from the seal or patient's face.

The headgear assembly3000of the respiratory mask system1000is used to hold the patient interface2000to the patient's face. The headgear assembly3000is typically attached to the patient interface2000and wraps tightly around the rear of the patient's head to seal the patient interface2000against the patient's face.

The headgear assembly1000may comprise an elastomeric yoke or collector100, which is configured to attach the headgear3000to the frame2100of the patient interface2000, as best shown inFIGS.1,5to13,15to18,20A to20C,21, and24to29. The yoke is configured to be stretched under tension to attach the yoke to the headgear assembly.

The elastomeric yoke100may be stretchable and/or flexible and may also be configured to attach to straps3100of the headgear assembly3000. In the embodiment shown inFIG.1, the headgear assembly3000comprises an assembly of straps3100, including a rear strap3110configured to wrap behind a patient's head, an upper strap3120configured to wrap over the top of a patient's head, and a pair of front straps3130configured to extend along the patient's cheeks during use. In one form, each front strap3130is attached to the rear strap3110of the headgear assembly3000by rear connectors3140. In another form, the rear strap3110comprises side extensions that form front straps3130to extend along the patient's cheeks during use.

Each front strap3130may comprise a free end to which may be attached a connector3140. Each connector3140may engage with a complementary strap connector101located on the yoke100. The connection between the front straps3130and yoke100may be any suitable form of connection, such as a snap-fit connection, a screw and thread type connection, or a hooked connection.FIGS.1,5to13,15to18,20A to20C,21, and24to29illustrate various forms of elastomeric yoke100that may be used to attach a headgear assembly3000to a frame2200. The yoke100comprises a substantially elongate body110having distal ends115a,115bthat may be configured to connect to headgear straps. For example, a strap connector101may be located at or near each end of the yoke100.

The elastomeric yoke100may be configured to attach any suitable headgear assembly3000to the frame2200. For example, in some forms, as shown inFIGS.6and6A, the yoke100may form a collector for filaments used in an automatically adjustable headgear system3000, such as those described in WO 2016/043603 and PCT/NZ20141000074 which are incorporated herein by reference. In this form, each side region of the yoke100may comprise a housing102or washer box comprising a washer mechanism (which may also be referred to as a directional lock) for the automatically adjustable headgear system The washer mechanism/directional lock may be configured to frictionally engage with a filament during elongation of the headgear, but to also allow relatively friction-free movement during retraction of the headgear3000. The washer box/directional lock housing102may comprise a substantially hollow recess formed in a side region of the yoke/collector100to receive the directional lock and filaments of the automatically adjustable headgear system3000within the yoke body110.

FIGS.30A to30Dshow one form of an automatically adjustable headgear system comprising a directional lock/washer mechanism within a housing/washer box, a first and a second lock element (e.g., washer1820,1822) and a filament/core member1830. The directional lock housing comprises a first and a second chamber1840,1842wherein the first and second chambers1840,1842are configured to house the first and second lock washers1820,1822, respectively. In the illustrated arrangement, the first and second chambers1840,1842are separated by an internal wall1812of the housing1810. However, in other arrangements, the first and second chambers1840,1842are not necessarily physically separate spaces, but can be portions of a chamber. The directional lock housing1810comprises two end walls1814, which along with the internal wall1812, have an elongate core opening/hollow recess1860for the filament/core member1830to pass through. The core openings1860are substantially aligned with each other. The core opening1860of the end wall1814shown on the right side of the figures is larger than the core opening of the internal wall1812and the end wall1814shown on the left of the figures. This allows for manipulation of the path of the filament/core member1830through the housing1810. The first and second chambers1840,1842are each delimited by the internal wall1812, one of the end walls1814and a pair of side walls1816; wherein the side walls1816extend between the end walls1814of the housing1810. The first and second chambers1840,1842are configured to be open at one or both of a top and a bottom of the housing1810.

Each of the first and second chambers1840,1842has a pair of washer retainers1850that are aligned on opposing side walls1816of the housing1810. Each pair of washer retainers1850is configured to pivotally retain one of the first or second lock washers1820,1822within the respective first or second chamber1840,1842. The washer retainers comprise a circular bush1852and an elongate slot1854, wherein circular bushes1852intersect with the bottom of the housing such that an entrance is formed. The entrance is configured to allow the first and/or second lock washers1820,1822to be received into the washer retainers1850. The slot1854extends radially from the circular bush1852towards the top of the housing1810.

The first and second washers1820,1822comprise a cylindrical shaft1824and an arm1826that extends from the shaft1824. The cylindrical shaft1824is substantially the same width W, as the housing1810and the arm1826is narrower to fit within the first and second chambers1840,1842. In the illustrated arrangement, the arm1826comprises a first section1872and a second section1874, wherein the first section1872extends radially or perpendicularly from the cylindrical shaft1824and the second section1874extends at an obtuse angle from the end of the first section1872. The first section1872of the arm1826of the first washer1820is shorter than the first section1872of the arm1826of the second washer1822. The angle between the first and second sections1872,1874of the arm1826of the first washer1820is greater than the corresponding angle of the second washer1822. The angles can be selected such that the second section1874of one or both of the first and second washers1820,1822lies substantially flat against the corresponding wall (e.g., internal wall1812and end wall1814, respectively) of the housing1810in one position of the washers1820,1822. The second section1874of the arm1826comprises a centrally located circular aperture1876configured to receive the core member1830. The first and second chambers1840,1842differ in size according to the size of the washer that is to be housed within it, i.e. the first chamber1840is smaller than the second chamber1842because the first washer1820is smaller than the second washer1822.

The cylindrical shafts1824of the first and second lock washers1820,1822have a diameter substantially the same as that of the circular bushes1852of the washer retainer1850, and are configured to be received and retained by the circular bush1852in a snap-fit configuration. The snap-fit configuration is provided by the entrance of the circular bush1852being narrower than the diameter of the cylindrical shaft1824. The slots1854of the washer retainers1850are configured to allow the entrance to be flexed open to increase the ease with which the first and second lock washers1820,1822can be pushed through the entrances and assembled to the housing1810. Once assembled within the first and second chambers1840,1842of the housing1810, the first and second washers1820,1822can pivot back and forward around a central axis that runs through the cylindrical shaft1824.

The filament/core member1830is configured to pass through the core openings1860of the housing1810and the apertures1876of the first and second washers1820,1822. Application of a tension force to the core member1830causes the first and second lock washers1820,1822to pivot back and/or forward between a locked position and/or open position.FIGS.30A and30Bshow the directional lock in a locked configuration in which a force is applied to the core member1830in a direction towards the left side of the figure (as indicated by the arrow). The force applied to the core member1830in this configuration causes the first and second lock washers1820,1822to pivot in an anti-clockwise direction, such that the path of the core member1830through the directional lock1800is non-linear or tortuous and movement of the core member1830is restricted.FIGS.30C and30Dshow the directional lock in an open configuration in which a force is applied to the core member1830in a direction towards the right side of the figure (as indicated by the arrow). In this configuration, the first and second lock washers1820,1822are pivoted in a clockwise direction such that the circular apertures1876and core openings1860are aligned in a substantially straight line. This provides a smooth path for the core member1830to be pulled substantially freely through the directional lock1800.

Optionally, the yoke100comprises at least one hollow collection chamber104for receiving at least one filament/core member of the adjustable headgear system1000. The hollow collection chamber104may open into and extend between the washer box housings102. For example, each hollow collection chamber typically aligns and connects with a respective core opening1860of the washer box/directional lock housing to form a pathway for a filament/core member1830so that a filament/core member1830can extend through a core opening1860and through a collection chamber in the yoke. In one form, as shown inFIG.6A, the yoke100may comprise two hollow collection chambers104a,104b, where each collection chamber is configured to receive a filament of the adjustable headgear system1000so as not to interfere with the filament or washer box of the other adjustment mechanism of the headgear. In one form, as shown inFIG.6A, each collection chamber104a,104bcomprises a hollow tube in which to receive a filament. The tube(s) may be over-moulded into the yoke100when the yoke is manufactured.

In another form, each end of the yoke100may be attached to a strap connector101or to a connector assembly comprising both a washer box housing102and a strap connector101configured to attach the yoke100to headgear3000. In this form, the washer box housings102and/or connectors101may be made separately from the yoke100and may be configured to attach to the ends of the yoke in any suitable arrangement, such as a snap-fit arrangement, or by over-moulding for example.

In one form, a washer box housing102is attached to each end of the yoke100and a headgear strap connector3140is attached to each washer box housing102, as shown inFIGS.7and8. Again, any suitable form of attachment may be used, such as a snap-fit arrangement, a magnetic connection, or over-moulding, for example.

The elastomeric yoke100may comprise a front surface111, a rear surface112, an upper surface113, and a lower surface114. The yoke may have a height defined by the distance between the upper surface and lower surface of the yoke and may have a length defined by the distance between opposing ends115of the yoke.

In one form, the yoke100may be angled or curved along its length and may comprise a middle region110clocated between two side regions110a,110b. In one form, the side regions110a,110bform a pair of arms extending from the middle region110cand terminating at the distal ends of the yoke100.

In one form, the cross-section of the yoke100may vary along its length. For example, in one form, the height of the middle region110cof the yoke is less than the height of the side regions110a,110bof the yoke, to create a yoke with a thinner middle region110cand flared ends115. By providing a yoke with a thin middle region110c, the height of the middle region210cof the yoke channel210may be thinner, which provides additional space on the frame body2210in which to locate a larger gas inlet2220and optionally also an outlet vent2200.

The elastomeric yoke100may be formed from any suitable material or combination of materials that allow the yoke to stretch and flex. For example, the yoke100may be formed from a rubberized material, silicone, or an elastomer.

The yoke100may be configured to engage with at least one retention member220on the frame2200of the patient interface2000to attach the yoke100to the frame.

In one form, the yoke may comprise one or more engagement members120and the frame may comprise one or more retention members220for engaging with the engagement member(s) of the yoke to hold the yoke100to the frame2200. Typically, the engagement member120of the yoke100and the retention member220of the frame are configured to hold the yoke100under tension when the yoke100is attached to the frame2200. The engagement members120and retention members220may take many different forms. Where the frame comprises a yoke channel, the yoke channel210may comprise one or more retention members220that are intended to prevent the yoke100from unintentionally disconnecting from the yoke channel210

In one form, the walls211,212,213of the yoke channel210may act as retention members, such as by being shaped to form retention members, by retention the yoke100within the channel210, such as under clamping or frictional forces. For example, the yoke100, when in an unstretched form, may be dimensioned to have a greater height than the height of at least a portion of the channel210. By stretching the yoke100, the yoke body110becomes thinner and may be fitted within the channel210. As the yoke100is released to its unstretched state, the height of the yoke increases again so that upper and lower surfaces113,114of the yoke press against upper and lower surfaces211,212of the channel to hold the yoke100within the channel210under clamping forces and/or frictional forces. The elastomeric material may provide additional grip or could be textured to provide even further grip.

In another form, as shown inFIGS.9and10, the yoke100comprises rounded edges. The rounded edges may improve the aesthetic appeal of the yoke and improve the feel of the yoke in a patient's hand. The softer look and feel of a yoke with rounded edges may be particularly fitting and appealing in a bedroom environment. In this embodiment, a washer box housing102may be connected directly between the yoke100and a strap connector101at each end of the yoke, rather than being integrally formed at an end of the yoke. The strap connector101and washer box housing102may be formed separately from the yoke100and may be configured to attach together by any suitable attachment system, such as a snap-fit arrangement or over-moulding, for example. Both the yoke100and the strap connectors101are preferably made from an elastomeric material so that both of these parts are flexible and substantially soft to touch.

In one form, at least a portion of the yoke channel210has a substantially rounded ‘C-shaped’ cross-section configured to substantially correspond with a yoke100having substantially rounded edges. The ‘C-shaped’ profile of the channel210may extend substantially along the entire length of the channel210or may be provided at only the middle region210cof the channel or only the side regions210a,210bof the channel. Preferably, the ‘C-shaped profile’ is provided in at least the middle region210cof the channel. For example, as shown inFIG.10, at least a portion of the yoke channel210may comprise a substantially ‘C-shaped’ cross-section in which the height of the opening214at the front of the channel H1is less than the maximum interior height H2of the yoke channel. In this configuration, edges of the upper and lower surfaces211,212of the channel each form a lip to define the front opening214of the channel. The lips of the channel210project toward each other so that the distance between the lips is less than the maximum distance between the upper and lower surfaces211,212of the channel. In a one form, the upper and lower surfaces211,212of the channel are substantially concave along the length of the channel210, so that the maximum distance between the upper and lower surfaces211,212is found at the mid-point of the curve. In one form, at least the middle region210cof the yoke channel comprises a substantially ‘C-shaped’ lateral cross-section with longitudinally concave upper and lower surfaces211,212. By providing a yoke channel210in which at least a portion of the yoke channel comprises a substantially ‘C-shaped’ lateral cross-section, it may be possible to improve the retention of a yoke100, having a substantially ‘C-shaped’ lateral cross-section, within the yoke channel210, due to the retention forces being applied to a larger surface area of the yoke, i.e. along the length of at least the middle region210cof the yoke, rather than only at a shoulder119or abutment surface121.

In its original state, the height of the yoke100(i.e. the maximum distance between the upper and lower surfaces of the yoke) is greater than the height H1of the channel opening214, but may be less than, substantially the same, or slightly greater than the interior height H2of the channel210. The elasticity of the stretchable/elastomeric yoke100means that the yoke may be stretched across the frame2200of the patient interface2000to become thinner in height so as to fit through the narrow front opening214of the yoke channel. When stretching the rounded yoke100across the frame2200, the yoke may also be twisted slightly so that one of the upper or lower surfaces113,114of the yoke enters the opening214of the yoke channel210first. This may reduce how much the yoke100needs to be stretched in order to fit through the opening214. The yoke100is then pushed fully into the channel210and released so that the yoke returns to its original un-stretched state. The surfaces of the unstretched yoke100press against surfaces of the channel210to hold the yoke within the lipped channel until such time as the yoke100is stretched to become thinner and is then pulled out of the channel210. In this way, walls211,212,213of the yoke channel210may act as retention members to hold the yoke100within the yoke channel210.

In another form, the frame2200may comprise at least one retention member220in the form of a projection222that is configured to engage with a recess122formed on the yoke100when the yoke is positioned within the yoke channel210, as indicated inFIG.11. Alternatively, the frame2200may comprise a retention member in the form of a recess224configured to engage with an engagement member in the form of a projection124, such as an arm or hook for example, provided on the yoke100when the yoke is located on the frame, as shown inFIG.12.

In yet another form, as indicated inFIG.11, the yoke channel210may comprise retention members220in the form of projecting tabs222that at least partially project across the front opening214of the yoke channel to protrude over the front surface111of the yoke when the yoke is located within the channel210.

Other suitable forms of retention members may be used to help secure the yoke within the yoke channel. For example, the yoke and frame may each comprise hooks configured to engage with each other.

Optionally, one or more walls211,212,213of the yoke channel210may be specially shaped to form a retention member220, such as an abutment surface221, that is configured to abut or engage with an engagement member120, such as an abutment surface121, of a yoke100to hold the yoke within the yoke channel210.

For example, as shown inFIGS.13to17, the yoke100may comprise at least one engagement member120in the form of an abutment surface121configured to clamp against a retention member220in the form of a corresponding abutment surface221of the frame. The yoke abutment surface121may generally face toward a virtual vertical line passing through the centre of the yoke100and may project from a rear and/or upper and/or lower surface112,113,114of the body110of the yoke. Similarly, the yoke channel210may comprise at least one complementary retention member in the form of an abutment surface221, which faces generally away from a virtual vertical line passing through the centre of the channel210and that is provided on the rear and/or upper and/or lower walls213,211,212of the yoke channel210respectively.

In another form, at least one abutment surface may be located on the frame, but outside of the yoke channel, for pressing against a corresponding abutment surface of a yoke.

An abutment surface121,221on the yoke and/or frame may be configured to help a user to locate the yoke100correctly within the yoke channel210of the frame. Optionally, an abutment surface on the yoke and/or frame121,221may be configured to ensure that the yoke100is oriented the right way up within the yoke channel210.

Preferably, the yoke100and frame2200each comprise a pair of abutment surfaces.121,221For example, each side of the yoke100may comprise an abutment surface121a,121b, preferably at the side regions110a,110bof the yoke or at a transitional region between the middle110cand side regions110a,110b. Similarly, each left and right side of the yoke channel210may comprise an abutment surface221a,221b, preferably at the side regions210a210bof the channel or at the transitional region between the middle210cand side regions210a,210c.

In one form, the yoke100may comprise a stepped profile so that the side regions110a,110bare larger than the middle region110c, as shown inFIGS.13and15. As shown inFIGS.14and15, the yoke channel210of the frame2200may comprise a substantially corresponding stepped profile so that the side regions210a,210bof the yoke channel210are larger than the middle region210cof the yoke channel210. Preferably, each abutment surface121,221is located at a transitional region between the middle region110c,210cand a side region110a,110b,210a,210bof the yoke100and of the yoke channel210. For example, the upper surface113of each side region110a,110bof the yoke may comprise a step or shoulder119so that the height of middle region110cof the yoke may be less than the height of the side regions110a,110b. Each step/shoulder119comprises a transitional surface between the middle110cand adjacent side region110a,110b. The transitional surface may comprise a sloping or substantially perpendicular abutment surface121between the upper surface113of the middle region110cand the upper surface113of the side region110a,110b.

Each abutment surface121of the yoke may be configured to substantially align with a corresponding abutment surface221of the yoke channel in the frame2200. For example, the side regions210a,210bof the upper wall211of the yoke channel may comprise a correspondingly shaped stepped profile to form a step or shoulder216so that the height of the yoke channel210at the side regions210a,210bis greater than at the middle region210c. Each step/shoulder216comprises a transitional surface between the middle210cand adjacent side region210a,210bof the channel210. The transitional surface may comprise a sloping or substantially perpendicular abutment surface221. The abutment surfaces121,221of the yoke and yoke channel should preferably substantially complement each other. Therefore, a sloping abutment surface121of the yoke should be configured to abut against a correspondingly sloped abutment surface221of the yoke channel. Similarly, a substantially perpendicular abutment surface121of the yoke should be configured to abut against a substantially perpendicular abutment surface221of the yoke channel.

In other forms, the lower or rear surface114,212of the yoke and channel may have at least one stepped or sloping transitional surface to provide an abutment surface121,221, as described above.

In yet another form, the stepped or sloping transitional surface may extend from the lower surface114,212around the upper113,211and rear surfaces112,213of the yoke and channel. Or the stepped of sloping transitional surface may be formed on the lower114,212and rear surfaces112,213of the yoke and channel; or on the lower114,212, rear112,213, and upper113,211surfaces of the yoke and channel.

In one form, as shown inFIGS.5,7,8,13,15, and17, the upper and/or lower surface(s)113,114of the yoke may be configured to provide a pair of abutment surfaces121that angle inwardly toward each other in a direction from the front surface111of the yoke toward the rear surface112. As shown inFIGS.4,5,14,15, and17, the abutment surfaces221of the yoke channel210may be correspondingly angled and located on the upper and/or lower surface(s)211,212of the channel, as the case may be.

In this form, the minimum distance W between abutment surfaces121on the yoke should be less than the maximum distance W1between abutment surfaces220on the yoke channel or frame, as shown inFIGS.13and14. In this configuration, to fit the yoke100within the yoke channel210, the yoke100is stretched so that the middle region110cof the yoke is longer than the middle region210cof the channel. Once the stretched yoke100is fitted within the channel210, the yoke may be released to its unstretched state. As the yoke100retracts to its unstretched state, the abutment surfaces121of the yoke retract towards and clamp against the abutment surfaces221of the yoke channel210under tension to hold the yoke in place within the channel210.

As will be appreciated, the stepped or sloping profiles of the abutment surfaces121,221of the yoke and yoke channel should substantially correspond in angle and location when the yoke100is fitted within the yoke channel210.

The engagement member(s)120of the yoke and the retention member(s)220of the frame2200may each form a hinge point around which at least the ends of the yoke100can flex, so that when the yoke is attached to front straps3130of headgear, the angle of each front strap is conformable to the patient's physiology. For example, abutment surfaces121,221of the yoke and yoke channel may each form a hinge point around which at least the ends of the yoke100can flex to form a comfortable respiratory mask system1000that sits well on the patient's face.

In some forms, the yoke100may be configured to provide one or more guides118, such as guiding surfaces configured to about one or more corresponding guides, such as guiding surfaces218on the frame210in order to help a patient to locate the yoke100correctly on the frame210. For example, the guiding surfaces118,218may comprise tapered lead in surfaces on the yoke100and the yoke channel210. In some forms, the guiding surfaces118,218may also act as abutment surfaces121/221to help retain the yoke100within the yoke channel210, as described above. For example, the yoke100may comprise one or more shoulders119, as described above, and the yoke channel210may comprise a substantially corresponding profile. One or more surfaces of the shoulders119of the yoke and yoke channel may comprise guiding surfaces118,218that may help a patient to guide the yoke to the correct location within the yoke channel.

In some embodiments, it may be preferred for the yoke and frame to each comprise at least two guiding surfaces—preferably one guiding surface at or near each side region of the yoke and of the frame.

Preferably, at least one guide/guiding surface118is provided on the rear and/or upper and/or lower surfaces112,113,114of the yoke. Similarly, at least one corresponding guide/guiding surface218may be provided on the rear and/or upper and/or lower walls213,211,212of the yoke channel. Additionally or alternatively, at least one guide/guiding surface may be located on the frame2200, but outside of the yoke channel.

In one form, the yoke may comprise one or more projections that project from the rear and/or upper and/or lower surface of the yoke. The projection(s) may each comprise at least one guiding surface configured to abut a corresponding guiding surface of the frame.

The guiding surfaces118of the yoke100may be substantially perpendicular to an adjacent surface112,113,114of the yoke body110or may slope at an angle of between 0-90° from the adjacent surface. For example, where the guiding surface118is located on the upper surface113of the yoke, the guiding surface118may slope at an angle of between 0-90° with respect to the upper surface113. Similarly, guiding surfaces218of the yoke channel210may be substantially perpendicular to an adjacent surface of the yoke channel or may slope at an angle of between 0-90° from an adjacent surface of the yoke channel210.

In one form, an over-moulding may be located at or near each end115or side region110a,100bof the yoke. One or more edges of the over-moulding may form one or more guiding surfaces118.

Whatever configuration of guides/guiding surfaces is used, the guiding surface(s)118of the yoke100preferably substantially correspond with the guiding surface(s) of the frame2200to correctly guide the yoke100into the yoke channel210.

The guides/guiding surfaces118,218provide an indicator that may help a patient to centre and align the yoke100correctly within the channel210. The indication provided by the guiding surfaces118may be particularly useful where the guiding surfaces are provided on shoulders119,216of a yoke and yoke channel that each have a substantially square stepped profile. This is because it is difficult for a patient to misalign the squared corners of the shoulders119,216. In some forms, the yoke100and channel210may be configured so that as the yoke100is fitted into the channel210, contact between the guiding surfaces118,218of the yoke and channel may provide tactile feedback to the patient that the yoke is correctly aligned and retained within the yoke channel.

In one form, as shown inFIG.17, the front surface111of the yoke is preferably smooth and may be configured to be substantially flush with the front surface2211of the frame when the yoke100is properly fitted within the yoke channel210. In this configuration, the flush front surfaces111,2211of the yoke and frame may provide a useful indication to a patient that the yoke100is correctly located within the channel210.

In one form substantially the whole of the body of the elastomeric yoke100may be stretchable. In yet another form, only a portion of the yoke100is stretchable. For example, only a portion of the yoke100may be formed from an elastomeric material.

In one form, as shown inFIG.15, the yoke100comprises a stretchable middle region110ccomprising an elastomeric material and rigid or semi-rigid side regions110a,110b. In one form, at least portions of the side regions110a,110bof the yoke may be substantially rigid to provide extra stability to the yoke100and to enhance the engagement between the yoke100and frame2200. The substantially rigid portions of the yoke may provide improved structure and stability to the front straps3130of the headgear, whilst maintaining flexibility due to the flexible nature of the connection with the elastomeric middle region110c, which allows the angle of the front straps3130to be variable, as shown inFIGS.17and29. In some forms, the side regions110a,110bmay each comprise a washer box housing102to hold a washer mechanism to be used with an automatically adjustable headgear system3000, as described above.

In one form, the substantially rigid portions of the yoke may be configured to provide haptic feedback that indicates to a patient that the yoke100is correctly fitted within the yoke channel210. The haptic feedback may be in the form of a clicking noise or a tactile click or connection feeling, for example.

The elastomeric nature of the yoke100allows the yoke to be manipulated (such as by stretching the yoke longitudinally) to fit within the yoke channel210and to hold the yoke in place within the channel210.

One process of fitting one form of elastomeric yoke100within a yoke channel210comprises the following steps, as shown inFIGS.16A to16C:

1. Press a first end115aof the yoke100into the corresponding first end of the yoke channel210. Where the yoke comprises shoulders119and abutment surfaces121, which may be formed on the shoulders119of the yoke, the process of fitting an elastomeric yoke100within a yoke channel210may also comprise the step of aligning the first abutment surface121aof the first shoulder119aof the yoke into abutment with the first abutment surface221of the corresponding first shoulder216aof the yoke channel210. Frictional forces should now hold the first end of the yoke100within the channel210, as shown inFIG.16B.

2. Wrap the free second end115bof the yoke100across the front opening of the yoke channel210to the other side of the frame2200.

3. Pull the free second end15bof the yoke100laterally away from the frame2200to stretch the yoke100so that the second abutment surface121bof the yoke is closer to the second end of the yoke channel210than is the second abutment surface221bof the yoke channel210.

4. Press the second end115bof the yoke100into the second end of the yoke channel210and release the yoke100. As the yoke is released, tension on the yoke is reduced so that the yoke retracts and the second abutment surface221bof the yoke100clamps against the second abutment surface221bof the yoke channel210, as shown inFIG.16C.

The yoke100should now be held within the channel210to secure the frame2200to the headgear3000. The free ends of the yoke100may project from the lateral ends215a,215bof the yoke channel210to attach to free ends of the headgear front straps3130.

In at least one embodiment, one process of fitting an elastomeric yoke100within a yoke channel210comprises the following steps:

holding or pressing a first end115aof the elastomeric yoke100to a corresponding first end215aof the yoke channel210;

applying tension to the yoke100to alter at least one dimension, shape, and/or configuration of the yoke, such as by stretching the yoke longitudinally for example;

placing or pressing the yoke100into a position in the yoke channel210;

releasing the tension to engage the yoke100with a retention member220, such as an abutment surface221or one or more walls of the yoke channel for example.

In at least one embodiment, the at least one dimension, shape, and/or configuration of the yoke100is a change in yoke cross-section or yoke length.

In at least one embodiment, the step of applying tension to the yoke100to alter at least one dimension, shape, and/or configuration of the yoke causes the length of the yoke to stretch and/or extend. In such an embodiment, a distance W between the first and second abutment surfaces121a,121bof the yoke100may be greater than a distance W1between the first and second abutment surfaces221a,221bof the yoke channel210.

In at least one embodiment, the step of releasing the tension on the yoke100causes the yoke to retract or reduce in length such that the second abutment surface121bof the yoke abuts with the second abutment surface221bof the yoke channel210. In at least some configurations the first and second abutment surfaces121a,121bof the tensioned yoke apply a compressive force to the first and second abutment surfaces221a,221bof the yoke channel210, such that the yoke100is retained within the yoke channel210.

In at least one embodiment, the yoke channel210comprises a ‘C-shaped’ cross-section. The step of applying tension to the yoke100to alter at least one dimension, shape, and/or configuration of the yoke reduces a height of the yoke100to be the same or less than a height H1of the yoke channel opening214of the ‘C-shaped’ cross-section.

In at least one embodiment, the step of applying tension to the yoke100to alter at least one dimension, shape, and/or configuration of the yoke allows the yoke to pass through the yoke channel opening214, when under tension.

In at least one embodiment, the step of releasing the tension on the yoke100to engage the yoke with a retention member220causes the height of the previously stretched yoke100to return to its original state, such that upper and lower surfaces113,114of the yoke then press against upper and lower surfaces211,212of the yoke channel to retain the yoke100within the yoke channel210.

In another embodiment, as shown inFIGS.18to27, the elastomeric yoke100may comprise a body110that comprises an elongate strip comprising elastomeric material. The yoke may be at least partially, and preferably fully, formed of elastomeric material so that the elastomeric portion of the yoke100may be configured to stretch longitudinally along its length. In some forms, the elastomeric portion of the yoke100may also be configured to stretch laterally along its height.

The yoke100may also comprise at least engagement member120in the form of a yoke aperture125formed within the body110of the yoke100. Each yoke aperture125may pass through the yoke100from the front surface111to the rear surface112of the yoke or to a midpoint or a point between the front and rear surfaces111,112of a multi-layered yoke, such as a two layered yoke.

One or more yoke apertures125may be formed in the yoke using any suitable method, such as by using a hole punch to form the yoke aperture(s), by laser cutting or blade cutting the aperture(s), or by 3-dimensionally knitting the yoke to form one or more apertures125in the yoke, for example.

Each yoke aperture125is configured to receive a retention member220of a frame2200of a patient interface2000. The retention member220may be a projecting arm223, such as a post, anchor point, or hook for example, that projects from the frame and that is configured to be at least partially received within the yoke aperture125. The frame may comprise a single retention member223for engagement with a single yoke aperture125. Alternatively, the frame2200may comprise two or more retention members223for engagement with two or more yoke apertures125. In yet another form, the yoke100may provide an adjustable fit by comprising multiple yoke apertures125for engagement with one or more retention members223of the frame, as shown inFIG.21.

Each yoke aperture125is configured to be placed over a projecting arm223of the frame2200, so that at least a portion of the arm223is held within the yoke aperture125. Preferably, the arm223extends through the yoke aperture125to project from the front surface111of the yoke.

In one form, the patient interface2000may comprise a pair of arms223projecting from left and right sides of the frame2200and the yoke100may comprise at least a pair of apertures125. The distance between the apertures125may be less than the distance between the arms223so that when the yoke is attached to the frame by placing the arms223through the apertures125, the yoke is held to the frame under tension.

For example,FIGS.18to21show one form of respiratory mask system1000comprising an elastomeric yoke100comprising at least a pair yoke apertures125for engagement with a pair of projecting arms223provided on a frame2200of a patient interface2000. In this form, the yoke100has a substantially elongate shape and is configured to stretch along its length when under tension. A yoke aperture125is provided on each side region110a,110bof the yoke100.

In one form, the frame2200may comprise a yoke channel210located on the front surface2211of the frame body2210. An arm223may project from each end215a,215bof the yoke channel210. Preferably, each arm223comprises rounded ends to help guide the arms223through respective yoke apertures125without catching or tearing at the yoke. This configuration is especially useful where the yoke is formed from a stretchy fabric.

The yoke100is configured to be at least partially located within the yoke channel210so that the upper and lower surfaces211,212of the yoke channel210may abut or lie adjacent to the respective upper and lower surfaces113,114of the yoke. The yoke channel210helps prevent the yoke100from slipping upwards or downwards on the frame2200. In this way, the yoke100can be located substantially centrally on the frame to help prevent skewing of the yoke relative to the frame2200.

In another form, the yoke may be configured to press against the front surface of the frame and to be held to the frame under tension, without the frame necessarily comprising a yoke channel.

The yoke100ofFIGS.18and20A to20Ccomprises a pair of yoke apertures125, one located at each side region110a,110bof the yoke so that the yoke apertures125lie proximate to the projecting arms223when the yoke is positioned alongside the yoke channel210. In one form, as shown inFIG.20A, each yoke aperture125is in the form of a slot and each arm223is in the form of a thin tab for projecting through a corresponding yoke aperture/slot125of the yoke100.

A method of attaching the yoke100to the frame2200is shown inFIGS.20A to20C. As a first step, the yoke100is positioned proximate to the front surface2211of the frame. One end of the yoke100is then attached to the frame by pulling the yoke over the frame and over the first arm223a, so that the first arm223aprojects through the first yoke aperture125a, as shown inFIG.20B. The elastomeric yoke is then stretched along its length and pulled across the frame2200and yoke channel210to align the second arm223bwith the second yoke aperture125b. The tension of the yoke100is then released to at least some extent to allow the second arm223bto project through the second yoke aperture125b. The yoke is now attached to the frame, as shown inFIG.20C. Preferably, the middle region of the yoke100that lies between the yoke apertures125a,125bremains slightly stretched and under tension as the yoke100is held against the frame2200. In this way, the yoke100is pulled taught across the frame2200to create a snug fit and to hold the patient interface2000against a patient's face.

The retention members/arms223and yoke apertures125may be provided at any suitable location on the frame2200that allows the yoke100to attach to the frame2200in a stable position and to hold the yoke under tension. For example, a pair of yoke apertures may be provided in the middle region of the yoke for attaching to corresponding arms223provided on a middle region of the yoke channel210or the frame2200.

In some forms, as shown inFIG.27, the lower wall212of the yoke channel210may comprise a guide218that forms a tongue extending downwardly from the yoke channel210. The guide218helps a user to correctly locate the yoke100in the yoke channel210by encouraging the yoke100to slide upward and into the channel210. Once the yoke100is in the correct position within the channel210, the upper wall211of the yoke channel prevents the yoke100from sliding further up the frame2200.

In some forms, it is not necessary for the frame of the patient interface to include a yoke channel within which a yoke may be held. The yoke100may alternatively be attached to retention members220formed on the front surface of the frame. For example, arms223may project from the front surface2211of the frame2200at any suitable location. Preferably, the arms223and corresponding yoke apertures125of the yoke are configured to hold the yoke under tension when the yoke is engaged with the arms. In one form, as shown inFIG.22, at least one arm223projects from opposing left and right sides of the frame2200. In other forms, two or more arms223may project from the left and right sides of the frame2200. For example,FIG.23shows a frame2200comprising a first pair of lower retention members/arms223a,223bprojecting from the left and right sides of a frame2200. The frame2200also comprises a second pair of upper retention members/arm223c,223dlocated above the lower arms223a,223band projecting from each of the left and right sides of the frame2200. In this form, a corresponding yoke may comprise a pair of upper and lower yoke apertures125. In this form, two yoke apertures are positioned on each of the left and right side regions110a,110bof the yoke, one aperture above the other, to engage with arms223a,223bon the respective left and right sides of the frame. Alternatively, the yoke100may have at least one engagement aperture125located at each side region of the yoke, as shown inFIGS.18and21. Each aperture125may be selectively engaged with one of the lower pair of arms223a,223bor one of the upper pair of arms223c,223d. In this configuration, the yoke and frame provide an adjustable fit for the user.

In both forms, the yoke100may be attached to the frame2200by engaging the yoke aperture(s)125on one side region of the yoke with the arm(s)223on a corresponding side of the frame, then stretching the yoke along its length to align the other yoke aperture(s) on the other side region of the yoke with the other arm(s) on the other side of the frame, before fitting the other arm(s) through the selected other yoke aperture(s) before releasing the yoke, as indicated inFIGS.20A to20C.

Where the yoke100comprises a series of yoke apertures125, extending along at least a portion of the length of the yoke, and a frame2200comprises one or more arms223, as shown inFIG.21, a user may select which yoke apertures to engage with the arm(s) in order to adjust the yoke to provide a comfortable fit.

FIGS.24to26show a portion of a frame body2210aand alternative forms of yoke comprising engagement members/yoke apertures125configured to engage with retention members/arms223of the frame to attach the yoke100to the frame2200. In these forms, the yoke comprises at least one pocket or loop and preferably at least two pockets or loops129for receiving and engaging with one or more arms223of the frame.

In the embodiments shown inFIGS.24and26, the yoke100comprises a multi-layered elastomeric body. Preferably, as shown, the yoke comprises two layers of fabric127,128that extend substantially along the length of the yoke. However, in other forms the yoke may comprise there or more layers of fabric. The yoke100also comprises a pair of apertures125, one of the apertures125being located on each side region110a,110bof the yoke. Each aperture125provides access to a pocket129provided on the yoke100. The pocket129is formed by an opening126that exists between the layers of fabric127,128. For example, where the yoke100comprises two layers of fabric, a first inner layer127of fabric may include yoke apertures125that allow access to an opening126formed between the first layer127and a second, outer layer128of fabric. Where the yoke comprises three or more layers of fabric, the yoke apertures may be formed in only the inner layer to provide access to a pocket opening between the inner layer and an adjacent layer, or the yoke apertures may be formed through two or more layers of fabric to provide access to a pocket opening between deeper layers of the yoke. In these forms, the fabric layers preferably extend substantially along the length of the yoke.

In another form, only some regions, such as the side regions, of the yoke may comprise multiple layers of fabric. Preferably, two layers of fabric are provided at each side region110a,100b. For example, in the embodiment shown inFIG.25, the yoke100may comprise a first layer128of elastomeric fabric that substantially extends across the length of the yoke. A second, inner layer127of fabric is provided at each side region110a,110bof the yoke so that each side region comprises two layers of fabric. A space or opening126is provided between the two layers127,128at each side region110a,110b. Each opening126can be accessed by at least one yoke aperture125, which may be formed through the inner layer of fabric. In another form, as shown, the yoke aperture125may be provided at an inside edge of the inner layer127of fabric. For example, an opening126may be formed between the two layers127,128at the point near the middle region110cof the yoke where the inner layer127terminates. This opening126may be created by stitching, bonding, welding or otherwise attaching upper and lower edges of the two fabric layers127,128together but not attaching the inside edge of the inner fabric layer127to the other fabric layer128. Other forms of creating a yoke aperture125at the edge of each inner layer may alternatively be used, such as 3-dimensionally knitting the yoke to have two or more layers of fabric127,128at the side regions110a,110b. The yoke apertures125provide access to the inner openings126to form pockets129within the yoke.

In yet another form, as indicated byFIG.25, the yoke100may comprise two or more layers of fabric127,128at two or more locations along the length of the yoke. In this form, the yoke100may comprise a first layer of fabric128that substantially extends along the length of the yoke. Loops130of a second layer of fabric127may also be provided at the side regions110a,110bor along the length of the yoke100. For example, the yoke may comprise a pair of loops130, one at each side region110a,110bof the yoke. Alternatively, the yoke100may comprise two or more loops130at each side region110a,110bor multiple loops130extending across the length of the yoke100to provide multiple attachments points/anchor points to engage with one or more retention members223to allow for an adjustable fit. As above, inner edges of the loops130may provide yoke apertures125that provide access to an opening between the looped fabric127and the first fabric layer128. The loops130act in a similar way to a pocket129in that each loop may receive and hold a retention member223between two layers of fabric127,128.

Each pocket129or loop130is configured to receive a corresponding retention member223within the pocket/loop. In this form, the yoke may be attached to a frame that does or does not comprise a yoke channel. The fabric layers may be made of the same material or different materials. For example, the inner layer of fabric may be softer than the outer layer to provide greater comfort to a user.

The pockets129/loops130may be formed by any suitable method. In one form, the yoke100may be 3-dimensionally knitted to include pockets or loops. In another form, the yoke100may include an inner layer127and an outer layer128of material joined together, such as by bonding, welding, stitching, fusing, or otherwise. The yoke apertures125may be formed in the inner layer127and a pocket may be formed between the inner and outer layers127,128. Each pocket129may comprise an open area between the inner and outer layers127,128of the yoke100, as shown inFIGS.24to26. The open area may be located next to a respective yoke aperture125and between that yoke aperture and an end115of the yoke.

In each of these embodiments, the frame and yoke may be dimensioned so that the middle region of the yoke (i.e. the region between the retention members) is held under tension when the yoke is attached to the frame. The tensile force helps to hold the yoke in position against the frame. To achieve this, the yoke apertures may be spaced at a distance from each other that is less than the distance between the retention members/arms.

One method of attaching the yoke to a patient interface is for a user to position a first engagement member, located at or near a first end of the yoke, adjacent to a first retention member on the patient interface, such as on the frame of a mask assembly. The first retention member may be located on a first side of the patient interface, such as on the left side for example. The first retention member is caused to engage with the first engagement member to hold the yoke to the patient interface at a first anchor point. The user then stretches the yoke along its length by pulling against the first anchor point until a second engagement member, located at or near the opposing to second end of the yoke, substantially aligns with a second retention member located on a second side, such as the right side, of the patient interface. The second engagement member is then caused to engage with the second retention member as the yoke is held under tension. The yoke is then released to at least partially release tension on the yoke. However, the yoke preferably remains under at least some tension to help hold the yoke to the patient interface.

In a more specific example of a method of attaching a yoke to a patient interface, a user pushes one end of a first retention member/arm223into a first yoke aperture125to hook the arm223around the yoke aperture and form a first anchor point. The user then stretches and deforms the yoke to place the yoke under tension as the user fits a second yoke aperture125around the other/second retention member223. The user then releases the yoke to release at least some of the tension on the yoke. Where the distances between the yoke apertures of the yoke, when unstretched in its natural state, is less than the distance between first and second retention members on opposing left and right sides of the patient interface, the yoke will remain under tension while it is attached to the patient interface. The tension in the yoke helps to hold the yoke firmly in position against the patient interface.

In yet another form, the frame2200may comprise a single retention member220. Preferably, the retention member forms a projecting arm223that is substantially centrally located on the front surface2211of the frame body2210. A corresponding yoke100may comprise an engagement member in the form of a yoke aperture125that is substantially centrally located along the length of the yoke100. The frame2200may or may not comprise a yoke channel210within which to receive the yoke100.

For example, as shown inFIGS.27,28A, and28B, the frame may comprise a yoke channel210having an upper surface211, a lower surface212, and a rear surface213, as described above. A retention member223, such as an arm, anchor point, or post for example, may project from the rear surface213at the middle region of the yoke channel210. The retention member/arm223may comprise a stem228and a capped distal end229that is wider, longer, or both wider and longer than the stem228. For example, the distal end229of the arm223may comprise a peripheral flange that projects outwardly beyond the periphery of the stem228. In one form, the arm223has a width that extends along a portion of the length of the yoke channel210to provide the arm with a substantially elongate width, as shown inFIG.27. In another form, the arm223may be a mushroom shape or any other suitable shape for engaging with a yoke aperture125.

An elastomeric yoke100having a substantially centrally located yoke aperture125may be provided for attachment to the frame2200, as shown inFIG.27. The yoke100may be configured to stretch along its length so that the yoke aperture125may be fitted over the capped end of the arm223so as to hold the stem of the arm223within the yoke aperture125.

FIGS.28A and28Bshow a method of attaching a yoke100to a patient interface. In this method, a user positions the engagement member of the yoke adjacent to the retention member on the patient interface, such as on the frame of a mask assembly. The user then hooks the engagement member around the retention member to hold the yoke in place.

More specifically, a user may push one end of the elongate retention member/arm223into the yoke aperture125to hook the arm around the yoke aperture and form a first anchor point. The user then stretches and deforms the yoke to place the yoke under tension as the user stretches the yoke aperture125to reach around the other end of the elongate retention member223. The user then releases the yoke to release at least some of the tension on the yoke. The yoke is caused to substantially revert toward its natural, unstretched state during which the yoke aperture125is smaller than the capped end229of the arm223and is therefore unable to disengage from the arm223without being stretched and pulled over the capped end229.

In other forms, the yoke may attach to other regions of the patient interface. For example, the yoke may attach to one or more retention members of the seal of a patient interface.

The elastomeric material of the yoke100allows the yoke to flex substantially horizontally and/or substantially vertically. For example, the yoke100may flex towards or away from the frame body2210and the patient's face. Correspondingly, the yoke100allows the connection between headgear3000and the frame2200to be flexible so that the ends of the front straps3130can be flexed towards or away from each other. The broken lines inFIG.29illustrate how the ends115of the yoke100may flex substantially horizontally and the arrow onFIG.17indicates how the ends115of the yoke may flex in a substantially vertical direction. Each side of the yoke100can flex independent of the other side so that a force applied to one side is isolated from the other side. This means that the yoke100may be particularly suitable for patients lying on their side because one side of the yoke100may flex, when being pressed against a pillow for example, without breaking the seal between the frame seal2100and the patient's face.

The flexible nature of the elastomeric yoke100also allows the yoke to conform to different face shapes and widths. For example, the ends115of the yoke may be flexible or may be directly or indirectly attached to flexible elastomeric connectors101,3140so that the ends115of the yoke or a yoke and connector assembly may flex toward or away from each other, or up and down relative to the middle region110cof the yoke. This flexibility prevents the yoke ends115or the connectors101,3140from digging into a patient's face.

The flexible yoke100may also improve the stability of the patient interface2000on a patient's face. For example, where a yoke100comprises projecting rigid ends115and the ends of the yoke become caught on bedding, a bending moment may result and may cause the patient interface2000to rotate on the patient's face. By providing a flexible yoke100, the ends115of the yoke may flex and move independently of the middle region110cof the yoke. Therefore, even if the yoke ends115become entangled in bedding, the flexible nature of the yoke100allows the patient interface2000to stay in the desired position on the patient's face The elastomeric yoke100may also be relatively simple to connect to the frame2200. For example, if the respiratory mask system comprises a yoke100and a frame2200having a yoke channel210for receiving the yoke, the yoke100and yoke channel210may be configured to provide a patient with tactile or haptic feedback when the yoke100is correctly fitted within the channel210.

The soft touch of the elastomeric material of the yoke100may also make the yoke100and headgear3000more comfortable to handle and may allude to the wash-ability of the headgear as a whole.

The elastomeric yoke allows the headgear assembly of the respiratory system to be easily removed from the patient interface/mask assembly without needing to laboriously disconnect components of the headgear assembly and mask assembly. In some forms, a user can detach the yoke and headgear from the mask assembly with one hand. Once detached, the yoke and headgear assembly may be washed. Where the yoke and headgear are made fully from fabric, the headgear assembly with yoke may be washed easily without concern for delicate non-fabric components.

The simplistic nature of the elastomeric yoke of the invention provides headgear bearing the yoke with a minimalist, uncomplicated aesthetically pleasing appearance. The headgear may also be lightweight.