Yoke for headgear

Abstract

To provide a yoke and headgear assembly for use in a respiratory system.SOLUTION: A headgear assembly 3000 for a respiratory system, the headgear comprising a yoke 100 formed at least in part from an elastomeric material. The yoke is configured to be stretched under tension to attach the yoke to the headgear assembly.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates generally to a respiratory system for delivering respiratory therapy to a patient. More particularly, the present disclosure relates to a yoke and headgear assembly for use in a respiratory system. [Background technology]

[0002] Respiratory masks are used to deliver respiratory therapy to the airways of individuals suffering from any of a number of respiratory diseases or conditions, including, but not limited to, continuous positive airway pressure (CPAP) therapy and non-invasive ventilation (NIV) therapy.

[0003] CPAP therapy can be used to treat obstructive sleep apnea (OSA), a condition in which a patient's airway becomes intermittently blocked during sleep, preventing the patient from breathing for periods of time. The interruptions in breathing, or apneas, result in the patient waking up. As a result of the repetitive and frequent apneas, patients are only occasionally able to achieve a sufficient, restorative night's sleep.

[0004] CPAP therapy involves delivering a supply of continuous positive airway pressure to a patient's airway via a breathing mask, which acts as a splint within the patient's airway, holding it in an open position so that the patient's breathing and sleep are uninterrupted.

[0005] Respiratory masks typically include a patient interface and headgear. The patient interface is configured to deliver a supply of continuous positive airway pressure to the patient's airway via a cushion module, which typically includes 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, and direct nose and mouth masks, which form an airtight seal against the nose and / or mouth. The cushion module is held in place on the patient's face by the headgear. To maintain an airtight seal, the headgear should provide support for the patient interface so that it is held in a stable position against the patient's face during use. Such respiratory masks can also be used to deliver NIV and other therapies.

[0006] As shown in FIG. 1, a yoke can be used to form a connection point between the headgear and the cushion module. The yoke has an intermediate region located between two ends, each of which is typically attached to the free end of a front strap of the headgear. Headgear that includes a yoke can generally be referred to as closed-loop headgear because the back strap, front strap, and yoke of the headgear are connected together to form a closed loop. The shape and width of the yoke determine the position of the end of the yoke (and its connection to the front strap of the headgear) relative to the patient's face. If the yoke is too flat and wide, a moment arm can be created, reducing the stability of the cushion module on the patient's face, as shown in FIG. 2. This problem can be exacerbated if the patient has a small head or a particularly narrow face. To overcome this problem, the yoke can be curved to position the end of the yoke closer to the patient's face, as shown in FIG. 3. However, if the yoke is curved too much, the end can dig into the patient's cheek, especially when rotational forces are applied to the yoke due to patient movement, as shown by the dashed line in FIG. 3. The ends of the yoke may also dig into the patient's cheeks if the head at the end of the yoke is large or if the facial contours are substantially flat. Summary of the Invention

[0007] The systems and devices described herein have innovative aspects, none of which is essential or solely responsible for the desired attributes of such systems and devices. Without limiting the scope of the claims, some of the advantageous features are summarized below.

[0008] In a first aspect, the present invention provides a headgear assembly for a patient interface of a respiratory system, the headgear comprising at least one strap for wrapping around a user's head and a yoke coupled to an end of the at least one strap, the yoke being formed at least in part from an elastomeric material, the yoke comprising at least one engagement member configured to be attached to at least one retention member of the patient interface.

[0009] Preferably, the headgear comprises a back strap connected to a pair of front straps, and the yoke comprises a middle region located between two side regions terminating at ends of the yoke, the ends of which are configured to connect to the free ends of the front straps.

[0010] Optionally, the yoke is formed entirely from an elastomeric material.

[0011] In one form, the yoke has an upper surface, a lower surface, a front surface, and a rear surface, and the upper and / or lower and / or rear surfaces of the yoke are provided with a pair of stepped regions, each step region separating a middle region from a respective side region. Optionally, each stepped region includes transition walls separating the middle region from the side regions, each transition wall forming an abutment surface configured to align with a corresponding abutment surface in a channel of the frame of the patient interface. Preferably, the abutment surfaces face each other and slope outwardly toward the distal ends of the yoke.

[0012] In one form, the side regions of the yoke are substantially rigid.

[0013] Optionally, each side region of the yoke comprises a washer box housing. In one form, the yoke comprises at least one collection chamber for receiving one or more filaments from the automatically adjustable headgear system.

[0014] In one form, the yoke has ends, each end connected to a headgear connector assembly, the headgear connector assembly including a washer box housing and a connector configured to connect to a front strap of the headgear.

[0015] In another form, the yoke has ends, each connected to a connector configured to connect to a front strap of the headgear.

[0016] Optionally, the yoke comprises substantially rounded edges.

[0017] In one form, the engagement member of the yoke includes an aperture and the retention member includes an arm configured to be received within the aperture.

[0018] In a second aspect, the present invention provides a breathing system comprising a patient interface comprising a mask assembly and a headgear assembly according to any one of the preceding claims.

[0019] In one form, the mask assembly comprises a seal and frame assembly, the frame having a front and a back, the front of the frame comprising a yoke channel extending laterally across the frame, the yoke channel configured to receive a yoke of a headgear assembly.

[0020] Optionally, the yoke channel has an upper surface, a lower surface, and a rear surface, the edges of the upper and lower surfaces each forming a lip defining a front opening of the channel, the lips of the channel projecting toward each other such that the maximum distance between the lips is less than the maximum distance between the upper and lower surfaces of the channel.

[0021] 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, giving the channel a substantially C-shaped cross-section.

[0022] Preferably, the yoke channel includes one or more retaining members configured to retain the yoke within the channel.

[0023] Optionally, each retention feature comprises a tab that intersects the yoke channel and projects at least partially forward of the yoke when the yoke is positioned within the channel.

[0024] In one form, the mask assembly includes a frame having a front and a back surface, with one or more retention members projecting from the front surface of the frame for engaging with one or more engagement members of the yoke.

[0025] Optionally, the mask assembly comprises a frame with a pair of arms, the arms protruding from left and right sides of the frame, and the yoke comprises at least one pair of openings, the distance between the openings being less than the distance between the arms.

[0026] In one form, each yoke opening provides access to a pocket or loop provided in the yoke, and each arm is configured to pass through a respective yoke opening and engage the pocket or loop.

[0027] In a third aspect, the present 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 retain the yoke to the patient interface at a first fastening point; pulling the yoke against the first fastening point until a second engagement member located at or near a second end of the yoke is substantially aligned with a second retention member located on the second side of the patient interface; while holding the yoke under tension, engaging the second retention member with the second engagement member; and releasing the yoke.

[0028] Also disclosed herein is a headgear assembly for a breathing system, the headgear including a back strap connected to a pair of front straps and a yoke formed at least in part from an elastomeric material, the yoke including a middle region located between two side regions terminating at distal ends of the yoke, the distal ends of the yoke configured to connect to free ends of the front straps of the headgear.

[0029] In one form, the yoke is formed entirely from an elastomeric material.

[0030] In one form, the yoke has an upper surface, a lower surface, a front surface, and a rear surface. The upper and / or lower and / or rear surface of the yoke can be provided with a pair of stepped regions, each step region separating a middle region from a side region. In one form, each stepped region includes a transition wall separating the middle region from the side region. The transition walls form abutment surfaces configured to align with corresponding abutment surfaces in the channel of the frame of the patient interface. Optionally, the abutment surfaces are angled toward each other in a direction from the front to the rear of the yoke.

[0031] In one form, the side regions of the yoke are substantially rigid.

[0032] Preferably, each side region of the yoke includes a washer box housing. In this configuration, the yoke can include at least one collection chamber for receiving one or more filaments from the automatically adjustable headgear system.

[0033] In one form, each end of the yoke is coupled to a headgear connector assembly including a washer box housing and a strap connector configured to couple to a front strap of the headgear. Alternatively, each end of the yoke is coupled to a connector configured to couple to a front strap of the headgear.

[0034] In one form, the yoke can have substantially rounded edges. In this form, the yoke can be configured to engage a frame, the frame having a yoke channel with a substantially C-shaped transverse cross-section.

[0035] Also disclosed herein is a breathing system comprising a patient interface with a cushion module and a headgear assembly according to the first aspect of the present invention.

[0036] In one form, the cushion module comprises a seal and frame assembly, the frame may have a front and a back surface, the front surface of the frame comprising a yoke channel extending laterally across the frame, the yoke channel being configured to receive a yoke of a headgear assembly.

[0037] In one form, the yoke channel has an upper surface, a lower surface, and a rear surface. The edges of the upper and lower surfaces may each form a lip that defines a front opening of the channel. The lips of the channel may project toward each other such 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, giving the channel a substantially "C-shaped" cross-section.

[0038] In one form, the yoke channel includes a plurality of retention features configured to retain the yoke within the channel, and each retention feature may optionally include a tab that intersects the yoke channel and projects at least partially forward of the yoke when the yoke is positioned within the channel.

[0039] Also disclosed herein is a respiratory mask system comprising a frame as disclosed herein and a yoke as disclosed herein, wherein the frame and yoke can comprise any feature or combination of features described herein.

[0040] Embodiments of systems, components, and methods of assembly and manufacturing are now described with reference to the accompanying figures. Like numbers refer to like or similar elements throughout the accompanying figures. While several embodiments, examples, and illustrations are disclosed below, those skilled in the art will appreciate that the invention described herein goes beyond the specifically disclosed embodiments, examples, and illustrations and can encompass other applications of the invention as well as obvious modifications and their equivalents. The terminology used in the description presented herein is not intended to be construed as limiting or restrictive, merely because it is used in conjunction with the detailed description of certain specific embodiments of the invention. Additionally, embodiments of the present invention may comprise several novel features, no feature being solely responsible for its desirable attributes or essential to practicing the invention described herein.

[0041] Certain terminology may be used in the following description for purposes of reference only and, therefore, such terminology is not intended to be limiting. For example, terms such as "top" and "bottom" refer to directions in the drawings to which reference is made.

[0042] Terms such as "top," "bottom," "upper," "lower," "front," "rear," "left," "right," "back," and "side" indicate the orientation and / or location of a component or portion of an element within a consistent, yet arbitrary, coordinate system that becomes apparent by reference to the text and associated drawings that describe the component or element under discussion. Additionally, terms such as "first," "second," and "third" may be used to describe separate components. Such terminology may include the terms specifically mentioned above, derivatives thereof, and terms of similar import. [Brief explanation of the drawings]

[0043] [Figure 1] FIG. 1 is a perspective view of a mask assembly including a headgear assembly with a yoke, a seal assembly, and a frame assembly. [Figure 2]FIG. 10 is a schematic plan view of a patient interface including a yoke for connecting headgear to a cushion module of the interface, illustrating how a poorly fitting yoke can shift relative to the patient's face. [Figure 3] FIG. 10 is another schematic plan view of the patient interface, illustrating how a poorly fitting yoke can shift relative to the patient's face. [Figure 4] FIG. 1 is a front view of one embodiment of a frame with a yoke channel. [Figure 5] FIG. 5 is a front view of the frame of FIG. 4 with the yoke coupled within the yoke channel. [Figure 6] FIG. 1 is a top view of one form of yoke having stepped regions on its top, back, and bottom surfaces, showing hidden details including a washer box housing and a pair of hollow collection chambers within the body of the yoke. [Figure 6A] 7 is a cross-sectional side view of the yoke of FIG. 6 taken along line BB, showing a tubular collection chamber within the yoke. [Figure 7] FIG. 10 is a rear perspective view of one form of a yoke with a connector assembly attached. [Figure 8] FIG. 8 is a front perspective view of the yoke and connector assembly of FIG. 7. [Figure 9] FIG. 10 is a perspective view of another configuration of a yoke and frame in which the yoke is elastomeric and has rounded edges configured to fit within a yoke channel having a substantially "C-shaped" cross section. [Figure 10] 8 is a schematic cross-sectional side view of one form of yoke channel having a substantially "C-shaped" cross-section to receive the rounded edged yoke shown in FIG. 7. FIG. [Figure 11] FIG. 10 is a front view of another configuration of the yoke and frame, in which the frame includes a retention feature in the form of a tab for retaining the yoke within the yoke channel of the frame. [Figure 12]FIG. 10 is a perspective view of one form of yoke and frame in which the frame includes a retaining member in the form of an opening and the yoke includes an engaging member in the form of a protrusion or hook configured to engage the opening in the frame to retain the yoke to the frame. [Figure 13] 7 is a top view of the yoke of FIG. 6 having a middle region located between two side regions and showing a guide surface that is sloped at the transition region between the middle and side regions. [Figure 14] 6 is a cross-sectional view taken through line AA of FIG. 5 showing a frame having curved channels with guide surfaces that are angled to engage with guide surfaces of a corresponding yoke. [Figure 15] 10A-10C are top perspective views of various configurations of a yoke and one configuration of a frame, in which the frame has a yoke channel with an abutment surface for engaging a yoke having a substantially corresponding abutment surface. [Figure 16A] 10A-10C illustrate how the elastomeric yoke fits into the yoke channel of the frame. [Figure 16B] 10A-10C illustrate how the elastomeric yoke fits into the yoke channel of the frame. [Figure 16C] 10A-10C illustrate how the elastomeric yoke fits into the yoke channel of the frame. [Figure 17] FIG. 10 is a side perspective view showing with arrows how the ends of the yoke of the present invention can bend substantially vertically. [Figure 18] FIG. 10 is a front perspective view of yet another form of elastomeric yoke attached to a form of frame assembly. [Figure 19] FIG. 19 is a side perspective view of the frame assembly of FIG. 18. [Figure 20A] 20 shows how the elastomeric yoke of FIG. 18 is attached to the frame assembly of FIGS. 18 and 19. FIG. [Figure 20B] 20 shows how the elastomeric yoke of FIG. 18 is attached to the frame assembly of FIGS. 18 and 19. FIG. [Figure 20C]20 shows how the elastomeric yoke of FIG. 18 is attached to the frame assembly of FIGS. 18 and 19. FIG. [Figure 21] FIG. 10 is a perspective view of an adjustable yoke and frame assembly in which the yoke provides an adjustment system to provide a comfortable fit for the user. [Figure 22] FIG. 10 is a perspective view of another form of frame for attachment to a yoke. [Figure 23] FIG. 10 is a perspective view of yet another form of frame that provides an adjustment system for attachment to a yoke. [Figure 24] 10A-10C illustrate a portion of one form of frame assembly and a portion of a yoke having a pocket that engages a retaining member or arm of the frame. [Figure 25] 1 is a schematic cross-sectional view of one embodiment of an elastomeric yoke having a pocket or loop for receiving a portion of a frame. [Figure 26] FIG. 10 is a cross-sectional view of another form of an elastomeric yoke having at least one pocket formed between two fabric layers, showing a yoke opening formed in the first fabric layer to allow a retaining member access to the opening to the pocket. [Figure 27] 13A-13C illustrate yet another form of frame assembly to which an elastomeric yoke can be attached, the frame assembly including a single retaining member or arm for engaging an opening in the yoke. [Figure 28A] 28 shows how the elastomeric yoke of FIG. 27 is attached to the frame of FIG. 27. FIG. [Figure 28B] 28 shows how the elastomeric yoke of FIG. 27 is attached to the frame of FIG. 27. FIG. [Figure 29] FIG. 10 is a schematic top view showing with arrows how the ends of the yoke of the present invention can bend substantially horizontally. [Figure 30A] FIG. 10 is a cross-sectional view of the washer box / directional lock housing of the adjustable headgear assembly showing the directional lock in a locked configuration. [Figure 30B]FIG. 10 is a cross-sectional view of the washer box / directional lock housing of the adjustable headgear assembly showing the directional lock in a locked configuration. [Figure 30C] FIG. 10 is a cross-sectional view of the washer box / directional lock housing of the adjustable headgear assembly showing the directional lock in an open configuration. [Figure 30D] FIG. 10 is a cross-sectional view of the washer box / directional lock housing of the adjustable headgear assembly showing the directional lock in an open configuration. DETAILED DESCRIPTION OF THE INVENTION

[0044] 4-29, the present invention relates to a respiratory mask system 1000 for delivering respiratory therapy to a patient. The mask system 1000 may include a patient interface 2000 and may include a headgear assembly 3000. The headgear assembly 3000 may include an elastomeric yoke 100 for attaching the headgear 3000 to the patient interface 2000. The yoke 100 may be integrally formed with one or more straps of the headgear 3000, or the yoke may be removably coupled to one or more straps of the headgear.

[0045] In one form, the patient interface 2000 comprises a seal and frame assembly. The seal 2100 may comprise a front or distal surface 2110 and a back or proximal surface 2120. The back surface 2120 of the seal 2100 may be configured to substantially seal against the patient's face during use. The seal 2100 may be configured to cover the patient's mouth, nose, or both. In one form, the seal 2100 comprises nasal pillows that substantially seal against the patient's nares. In another form, the patient interface 2000 is a non-sealing interface, such as a nasal cannula configured for high-flow therapy.

[0046] The frame 2200 of the patient interface 2000 can be configured to attach the patient interface 2000 to the headgear 3000. In one form, as shown in FIGS. 1 , 4 , 5 , and 13 , the frame 2200 comprises a body 2210 having a first surface or front surface 2211 and a substantially opposing second surface or back surface 2212. The frame 2200 can also comprise a gas inlet 2220 configured to be attached to a gas conduit 4000 for delivering gas to the patient through the patient interface 2000. Optionally, the frame 2200 can also comprise one or more outlet ventilation holes 2200. The elastomeric yoke 100 is typically configured to attach the headgear 3000 to the frame 2200.

[0047] In one form, the front surface 2211 of the frame includes a yoke channel 210 configured to receive at least a portion of the yoke of the headgear assembly 3000. The yoke channel 210 can extend from left to right across at least a portion of the front surface 2211 of the frame 2200.

[0048] 4, 5, and 10, the yoke channel 210 may be defined by a first wall 211 that, in use, forms an upper surface, a second wall 212 that forms a lower surface substantially opposite the first wall 211, and a third wall 213 that forms a back surface extending between the first wall 211 and the second wall 212. The channel 210 may have two side regions 210a, 210b, each located at opposite ends of the channel 210, with a middle region 210c located substantially centered between the two side regions 210a, 210b.

[0049] In one form, the height H2 of the back surface 213 of the channel 210 can be substantially defined by the distance between the top wall 211 and the bottom wall 212 of the channel 210. In the middle region 210c of the channel 210, the maximum height of the channel 210 can be less than the maximum height of the channel 210 in one or both side regions 210a, 210b. For example, the top surface 211 or the bottom surface 212 of the channel 210 can be curved or sloped toward the opposing surface 212, 211 to form a peak located substantially at a midpoint along the length of the channel 210.

[0050] 10 , the maximum height H1 of the front opening 214 of the yoke channel 210 (i.e., the distance between the edges of the channel at the front surface of the frame) can be less than the maximum height H2 between the upper wall 211 and the lower wall 212 of the interior of the yoke channel 210. For example, the height H1 of the channel opening 214 can be less than the height H2 of the rear surface 213 of the channel 210. In some embodiments, the maximum height H1 of the channel opening 214 is less than the maximum height H2 of the interior of the channel 210 only in the intermediate region 210c of the channel.

[0051] In one form, the lower surface 212 of the yoke channel 210 may be angled inwardly toward the rear surface 213 of the channel.

[0052] In one form, the top surface 211 of the yoke channel may be angled inwardly toward the back surface 213 of the channel 210 .

[0053] In one form, the depth of the lower surface 212 of the yoke channel 210 can be substantially defined by the distance between the back surface 213 of the channel and the front edge 212a of the lower surface 212, where the lower surface 212 meets the front surface 2211 of the frame 2200. In one form, the depth of the lower surface 212 of the yoke channel can be greater in areas adjacent the retaining member 220 or abutment surface 221 (which retain the yoke within the yoke channel) than at the lateral ends of the intermediate region 210c of the channel or the side regions 210a, 210b or ends 215a, 215b of the channel 210. In another form, the depth of the lower surface 212 can taper toward the ends of the yoke channel 210.

[0054] In one form, the depth of the lower surface 212 tapers from a first depth adjacent the abutment surface 221 of the yoke channel 210 to a second depth at the lateral ends 215 a , 215 b of the yoke channel 210 .

[0055] Frame 2200 and yoke channel 210 may be substantially curved from left to right to somewhat match the curvature around the patient's nose or mouth. Alternatively or additionally, frame 2200 and / or yoke channel 210 may be angled or curved downward from top to bottom, toward or away from the seal or patient's face.

[0056] The headgear assembly 3000 of the respiratory mask system 1000 is used to hold the patient interface 2000 to the patient's face. The headgear assembly 3000 is typically attached to the patient interface 2000 and wrapped tightly around the back of the patient's head to seal the patient interface 2000 to the patient's face.

[0057] The headgear assembly 3000 can include an elastomeric yoke or collector 100 configured to attach the headgear 3000 to the frame 2200 of the patient interface 2000, as best shown in Figures 1, 5-13, 15-18, 20A-20C, 21, and 24-29. The yoke is configured to be stretched under tension to attach the yoke to the headgear assembly.

[0058] The elastomeric yoke 100 can be stretchable and / or flexible and can be configured to attach to straps 3100 of a headgear assembly 3000. In the embodiment shown in FIG. 1 , the headgear assembly 3000 comprises an assembly of straps 3100 including a back strap 3110 configured to wrap around the back of a patient's head, an upper strap 3120 configured to wrap over the patient's head, and a pair of front straps 3130 configured to extend along the patient's cheeks in use. In one form, each front strap 3130 is attached to the back strap 3110 of the headgear assembly 3000 by a back connector 3140. In another form, the back straps 3110 comprise side extensions that form the front straps 3130 that extend along the patient's cheeks in use.

[0059] Each front strap 3130 can have a free end to which a connector 3140 can be attached. Each connector 3140 can engage a complementary strap connector 101 located on the yoke 100. The connection between the front strap 3130 and the yoke 100 can be any suitable form of connection, such as a snap-fit ​​connection, a screw and thread connection, or a hook-type connection. FIGS. 1, 5-13, 15-18, 20A-20C, 21, and 24-29 show various forms of elastomeric yoke 100 that can be used to attach the headgear assembly 3000 to the frame 2200. The yoke 100 includes a substantially elongated body 110 having ends 115a, 115b that can be configured to connect to headgear straps. For example, a strap connector 101 can be located at or near each end of the yoke 100.

[0060] The elastomeric yoke 100 can be configured to attach any suitable headgear assembly 3000 to the frame 2200. For example, in some forms, as shown in FIGS. 6 and 6A , the yoke 100 can form a collector for filaments used in an automatically adjustable headgear system 3000, such as those described in International Publication No. WO 2016 / 043603 and International Application No. PCT / NZ2014 / 000074, which are incorporated herein by reference. In this form, each side region of the yoke 100 can include a housing 102 or washer box that includes a washer mechanism (also referred to as a directional lock) for the automatically adjustable headgear system. The washer mechanism / directional lock can be configured to frictionally engage the filaments during headgear extension, but allow relatively frictionless movement during headgear retraction. The washer box / directional lock housing 102 may comprise a substantially hollow recess formed in a side region of the yoke / collector 100 to receive the directional lock and filament of the automatically adjustable headgear system 3000 within the yoke body 110.

[0061] 30A-30D show one form of an automatically adjustable headgear system including a directional lock / washer mechanism within a housing / washer box, first and second locking elements (e.g., washers 1820, 1822), and a filament / core member 1830. The directional lock housing includes a first chamber 1840 and a second chamber 1842 configured to receive a first lock washer 1820 and a second lock washer 1822, respectively. In the illustrated arrangement, the first chamber 1840 and the second chamber 1842 are separated by an interior wall 1812 of the housing 1810. However, in other arrangements, the first chamber 1840 and the second chamber 1842 are not necessarily physically separate spaces and can be part of a single chamber. The directional lock housing 1810 includes two end walls 1814, which, together with an inner wall 1812, define an elongated core opening / hollow recess 1860 for passage of the filament / core member 1830. The core openings 1860 are substantially aligned with one another. The core opening 1860 in the end wall 1814 shown on the right side of the figure is larger than the core openings in the inner wall 1812 and end wall 1814 shown on the left side of the figure. This allows for control of the path of the filament / core member 1830 through the housing 1810. The first chamber 1840 and the second chamber 1842 are each bounded by the inner wall 1812, one of the end walls 1814, and a pair of side walls 1816, which extend between the end walls 1814 of the housing 1810. The first chamber 1840 and the second chamber 1842 are configured to be open at one or both of the top and bottom of the housing 1810 .

[0062] The first chamber 1840 and the second chamber 1842 each have a pair of aligned washer retainers 1850 on opposing sidewalls 1816 of the housing 1810. Each pair of washer retainers 1850 is configured to pivotally retain one of the first lock washer 1820 or the second lock washer 1822 within the respective first chamber 1840 or second chamber 1842. The washer retainers include a circular bushing 1852 and an elongated slot 1854, where the circular bushing 1852 intersects with the bottom of the housing to form an entrance. The entrance is configured to allow the first lock washer 1820 and / or the second lock washer 1822 to be received in the washer retainer 1850. The slot 1854 extends radially from the circular bushing 1852 toward the top of the housing 1810.

[0063] The first washer 1820 and the second washer 1822 each include a cylindrical shaft 1824 and an arm 1826 extending from the shaft 1824. The cylindrical shaft 1824 has substantially the same width W, while the housing 1810 and the arm 1826 are narrower to fit within the first chamber 1840 and the second chamber 1842. In the illustrated arrangement, the arm 1826 includes a first section 1872 and a second section 1874, where the first section 1872 extends radially or orthogonally from the cylindrical shaft 1824 and the second section 1874 extends at an obtuse angle from the end of the first section 1872. The first section 1872 of the arm 1826 of the first washer 1820 is shorter than the first section 1872 of the arm 1826 of the second washer 1822. The angle between the first section 1872 and the second section 1874 of the arm 1826 of the first washer 1820 is greater than the corresponding angle of the second washer 1822. These angles can be selected so that the second section 1874 of one or both of the first washer 1820 and the second washer 1822 substantially flush against a corresponding wall of the housing 1810 (e.g., the interior wall 1812 and the end wall 1814, respectively) at one location on the washers 1820, 1822. The second section 1874 of the arm 1826 includes a centrally located circular opening 1876 configured to receive the core member 1830. The first chamber 1840 and the second chamber 1842 are different sizes depending on the size of the washers they are to accommodate, i.e., the first chamber 1840 is smaller than the second chamber 1842 because the first washer 1820 is smaller than the second washer 1822.

[0064] The cylindrical shafts 1824 of the first and second lock washers 1820, 1822 have substantially the same diameter as the circular bushings 1852 of the washer retainer 1850 and are configured to be received and retained in a snap-fit ​​arrangement by the circular bushings 1852. The snap-fit ​​arrangement is provided by an entrance to the circular bushings 1852 that is narrower than the diameter of the cylindrical shafts 1824. The slots 1854 of the washer retainer 1850 are configured to allow the entrances to flex open to increase the ease with which the first and second lock washers 1820, 1822 can be pressed into the entrances and assembled to the housing 1810. After being assembled within the first chamber 1840 and second chamber 1842 of the housing 1810, the first washer 1820 and second washer 1822 can pivot rearward and forward about a central axis extending through the cylindrical shaft 1824.

[0065] The filament / core member 1830 is configured to pass through the core opening 1860 in the housing 1810 and the openings 1876 in the first and second washers 1820 and 1822. Applying tension to the core member 1830 causes the first and second lock washers 1820 and 1822 to pivot rearward and / or forward between the locked and / or open positions. FIGS. 30A and 30B show the directional lock in a locked configuration, with a force being applied to the core member 1830 toward the left side of the figure (indicated by the arrow). A force applied to the core member 1830 in this configuration causes the first and second lock washers 1820 and 1822 to pivot in a counterclockwise direction, thereby creating a nonlinear or serpentine path for the core member 1830 through the directional lock 1800 and restricting movement of the core member 1830. 30C and 30D show the directional lock in an open configuration, with a force being applied to the core member 1830 in a direction toward the right of the figure (indicated by the arrow). In this configuration, the first lock washer 1820 and the second lock washer 1822 are pivoted in a clockwise direction, such that the circular opening 1876 and the core opening 1860 are aligned in a substantially straight line. This provides a smooth path for the core member 1830 to pass substantially freely through the directional lock 1800.

[0066] Optionally, the yoke 100 includes at least one hollow collection chamber 104 for receiving at least one filament / core member of the adjustable headgear system 3000. The hollow collection chambers 104 can open into and extend between the washer box housings 102. For example, each hollow collection chamber typically aligns with and couples with a respective core opening 1860 of the washer box / directional lock housing to form a pathway for the filament / core member 1830, such that the filament / core member 1830 can extend through the core opening 1860 and the collection chamber in the yoke. In one form, as shown in FIG. 6A , the yoke 100 can include two hollow collection chambers 104a, 104b, each configured to receive the filament of the adjustable headgear system 3000 without interfering with the filaments or washer boxes of other adjustment mechanisms of the headgear. In one form, as shown in Figure 6A, each collection chamber 104a, 104b comprises a hollow tube for receiving a filament. The tube(s) can be overmolded into the yoke 100 when the yoke is manufactured.

[0067] In another form, each end of the yoke 100 can be attached to a strap connector 101 or connector assembly, which includes both a washer box housing 102 and a strap connector 101 configured to attach the yoke 100 to the headgear 3000. In this form, the washer box housing 102 and / or connector 101 can be made separately from the yoke 100 and configured to attach to the ends of the yoke in any suitable configuration, such as a snap-fit ​​configuration or by, for example, overmolding.

[0068] 7 and 8, a washer box housing 102 is attached to each end of the yoke 100 and a headgear strap connector 3140 is attached to each washer box housing 102. Again, any suitable form of attachment can be used, such as, for example, a snap-fit ​​arrangement, magnetic coupling, or overmolding.

[0069] The elastomeric yoke 100 can have a front surface 111, a back surface 112, a top surface 113, and a bottom surface 114. The height of the yoke can be defined by the distance between the top and bottom surfaces of the yoke, and the length of the yoke can be defined by the distance between ends 115 of the yoke.

[0070] In one form, the yoke 100 may be tapered or curved along the length of the yoke 100 and may include a middle region 110c located between two side regions 110a, 110b. In one form, the side regions 110a, 110b form a pair of arms that extend from the middle region 110c and terminate at the ends of the yoke 100.

[0071] In one form, the cross-section of the yoke 100 can vary along the length of the yoke 100. For example, in one form, the height of the yoke's middle region 110c is less than the height of the yoke's side regions 110a, 110b, forming a yoke with a narrower middle region 110c and flared ends 115. By narrowing the yoke's middle region 110c, the height of the yoke channel 210's middle region 210c can be made lower, thereby providing additional space in the frame body 2210 for locating a larger gas inlet 2220 and, optionally, outlet ventilation holes 2200.

[0072] The elastomeric yoke 100 can be formed from any suitable material or combination of materials that allows the yoke to stretch and flex. For example, the yoke 100 can be formed from a rubberized material, silicone, or an elastomer.

[0073] The yoke 100 can be configured to engage at least one retention member 220 of a frame 2200 of the patient interface 2000 for attaching the yoke 100 to the frame.

[0074] In one form, the yoke can include one or more engagement members 120, and the frame can include one or more retention members 220 that engage the yoke's engagement member(s) to retain the yoke 100 to the frame 2200. Typically, the engagement members 120 of the yoke 100 and the retention members 220 of the frame are configured to hold the yoke 100 under tension when the yoke 100 is attached to the frame 2200. The engagement members 120 and the retention members 220 can take many different forms. If the frame includes a yoke channel, the yoke channel 210 can include one or more retention members 220 intended to prevent the yoke 100 from being unintentionally removed from the yoke channel 210.

[0075] In one form, the walls 211, 212, 213 of the yoke channel 210 can act as retaining members, such as by being shaped to form retaining members, by retaining the yoke 100 within the channel 210 under clamping or frictional forces. For example, the yoke 100 can be dimensioned to have a height greater than the height of at least a portion of the channel 210 when in an unstretched configuration. By stretching the yoke 100, the yoke body 110 becomes thinner and can fit within the channel 210. When the yoke 100 is released to its unstretched state, the height of the yoke again increases, causing the upper and lower yoke surfaces 113, 114 to press against the upper and lower channel surfaces 211, 212, retaining the yoke 100 within the channel 210 under clamping and / or frictional forces. The elastomeric material can provide additional grip or can be textured to provide further grip.

[0076] In another form, as shown in FIGS. 9 and 10 , the yoke 100 includes rounded edges. The rounded edges can improve the aesthetic appeal of the yoke and how it feels in a patient's hand. The softer look and feel of a yoke with rounded edges can be particularly appealing in a bedroom environment. In this embodiment, the washer box housing 102 can be coupled directly between the yoke 100 and the strap connector 101 at each end of the yoke, rather than being integrally formed at the ends of the yoke. The strap connector 101 and the washer box housing 102 can be formed separately from the yoke 100 and configured to be attached together by any suitable attachment system, such as a snap-fit ​​arrangement or overmolding. Both the yoke 100 and the strap connector 101 are preferably made from an elastomeric material, so that both parts are flexible and substantially soft to the touch.

[0077] In one form, at least a portion of the yoke channel 210 has a substantially rounded "C-shaped" cross-section configured to substantially correspond to a yoke 100 having substantially rounded edges. The "C-shaped" profile of the channel 210 can extend substantially along the entire length of the channel 210, or can be provided only in the middle region 210c of the channel or only in the side regions 210a, 210b of the channel. Preferably, the "C-shaped profile" is provided at least in the middle region 210c of the channel. For example, as shown in FIG. 10 , at least a portion of the yoke channel 210 can have a substantially "C-shaped" cross-section, with the height H1 of the opening 214 at the front of the channel being less than the maximum internal height H2 of the yoke channel. In this configuration, the edges of the upper and lower surfaces 211, 212 of the channel each form a lip that defines the front opening 214 of the channel. The lips of the channel 210 project toward each other such that the distance between the lips is less than the maximum distance between the upper and lower surfaces 211, 212 of the channel. In one form, the upper and lower surfaces 211, 212 of the channel are substantially concave along the length of the channel 210, such that the maximum distance between the upper and lower surfaces 211, 212 is found at the midpoint of the curvature. In one form, at least the intermediate region 210c of the yoke channel has a substantially “C-shaped” transverse cross-section with longitudinally concave upper and lower surfaces 211, 212. Providing a yoke channel 210 in which at least a portion of the yoke channel has a substantially “C-shaped” transverse cross-section can facilitate improved retention of a yoke 100 having a substantially “C-shaped” transverse cross-section in the yoke channel 210 because the retention force is applied to a larger surface area of ​​the yoke, i.e., at least along the length of the intermediate region 210c of the yoke, rather than just to the shoulder 119 or abutment surface 121.

[0078] In the original state of the yoke 100, the height of the yoke 100 (i.e., the maximum distance between the top and bottom surfaces of the yoke) is greater than the height H1 of the channel opening 214, but less than the internal height H2 of the channel 210, and can be substantially the same as, or slightly greater. The resilience of the stretchable / elastomeric yoke 100 means that the yoke can be stretched across the frame 2200 of the patient interface 2000 to a smaller height so that it fits into the narrow front opening 214 of the yoke channel. When stretching the round yoke 100 across the frame 2200, the yoke can also be twisted slightly so that one of the top surface 113 or bottom surface 114 of the yoke first enters the opening 214 of the yoke channel 210. This reduces how much the yoke 100 needs to be stretched to fit through the opening 214. The yoke 100 can then be pushed all the way into the channel 210 and released, and the yoke will return to its original, unstretched state. The surface of the unstretched yoke 100 presses against the surface of the channel 210 to retain the yoke within the lip-like channel, after which the yoke 100 is stretched to become thinner and then pulled out of the channel 210. In this manner, the walls 211, 212, 213 of the yoke channel 210 can act as retaining members to retain the yoke 100 within the yoke channel 210.

[0079] 11, the frame 2200 can include at least one retaining member 220 in the form of a protrusion 222 configured to engage with a recess 122 formed in the yoke 100 when the yoke is positioned in the yoke channel 210. Alternatively, as shown in FIG. 12, the frame 2200 can include a retaining member in the form of a recess 224 configured to engage with an engaging member in the form of a protrusion 124, such as an arm or hook, provided on the yoke 100 when the yoke is located on the frame.

[0080] In yet another form, as shown in FIG. 11 , the yoke channel 210 can include a retention member 220 in the form of a protruding tab 222 that at least partially intersects the front opening 214 of the yoke channel and protrudes above the front surface 111 of the yoke when the yoke is positioned within the channel 210.

[0081] Other suitable forms of retaining members may be used to help secure the yoke within the yoke channel. For example, the yoke and frame may each include hooks configured to engage with each other.

[0082] Optionally, one or more walls 211, 212, 213 of the yoke channel 210 may be specially shaped to form a retaining member 220, such as an abutment surface 221, configured to abut or engage with an engaging member 120, such as an abutment surface 121, of the yoke 100 to retain the yoke within the yoke channel 210.

[0083] For example, as shown in Figures 13-17, the yoke 100 can include at least one engagement member 120 in the form of an abutment surface 121 configured to fasten to a corresponding retaining member 220 in the form of an abutment surface 221 on the frame. The yoke abutment surface 121 can face generally toward an imaginary vertical line passing through the center of the yoke 100 and can protrude from the back surface 112 and / or the top surface 113 and / or the bottom surface 114 of the yoke body 110. Similarly, the yoke channel 210 can include at least one complementary retaining member in the form of an abutment surface 221 facing generally away from the imaginary vertical line passing through the center of the channel 210 and provided on the back wall 213 and / or the top wall 211 and / or the bottom wall 212 of the yoke channel 210, respectively.

[0084] In another form, at least one abutment surface can be located on the frame outside the yoke channel to press against a corresponding abutment surface on the yoke.

[0085] The abutment surfaces 121, 221 of the yoke and / or frame can be configured to assist a user in accurately positioning the yoke 100 within the frame's yoke channel 210. Optionally, the abutment surfaces 121, 221 of the yoke and / or frame can be configured to ensure that the yoke 100 is properly oriented up and down within the yoke channel 210.

[0086] The yoke 100 and the frame 2200 preferably each include a pair of abutment surfaces 121, 221. For example, each side of the yoke 100 may include an abutment surface 121a, 121b, preferably located at the side regions 110a, 110b of the yoke or at the transition region between the intermediate region 110c and the side regions 110a, 110b. Similarly, the left and right sides of the yoke channel 210 may include abutment surfaces 221a, 221b, respectively, preferably located at the side regions 210a, 210b of the channel or at the transition region between the intermediate region 210c and the side regions 210a, 210b.

[0087] In one form, as shown in Figures 13 and 15, the yoke 100 can have a stepped profile, such that the side regions 110a, 110b are larger than the middle region 110c. As shown in Figures 14 and 15, the yoke channel 210 of the frame 2200 can have a substantially corresponding stepped profile, such that the side regions 210a, 210b of the yoke channel 210 are larger than the middle region 210c of the yoke channel 210. Each abutment surface 121, 221 is preferably located in a transition region between the middle region 110c, 210c and the side regions 110a, 110b, 210a, 210b of the yoke 100 and yoke channel 210. For example, the top surface 113 of each side region 110a, 110b of the yoke can have a step or shoulder 119, such that the height of the middle region 110c of the yoke can be smaller than the height of the side regions 110a, 110b. Each step / shoulder 119 comprises a transition surface between the intermediate region 110c and the adjacent side region 110a, 110b. The transition surface may define an inclined or substantially perpendicular abutment surface 121 between the top surface 113 of the intermediate region 110c and the top surface 113 of the side region 110a, 110b.

[0088] Each abutment surface 121 of the yoke can be configured to substantially align with a corresponding abutment surface 221 of the yoke channel in the frame 2200. For example, the side regions 210a, 210b of the top wall 211 of the yoke channel can have a correspondingly shaped stepped profile to form a step or shoulder 216, such that the height of the yoke channel 210 at the side regions 210a, 210b is greater than the middle region 210c. Each step / shoulder 216 provides a transition surface between the middle region 210c of the channel 210 and the adjacent side region 210a, 210b. The transition surface can define an inclined or substantially perpendicular abutment surface 221. Preferably, the abutment surfaces 121, 221 of the yoke and yoke channel should substantially complement each other. Thus, the inclined abutment surface 121 of the yoke should be configured to abut the corresponding inclined abutment surface 221 of the yoke channel. Similarly, the substantially orthogonal abutment surface 121 of the yoke should be configured to abut the substantially orthogonal abutment surface 221 of the yoke channel.

[0089] In other forms, the lower surface 114 or rear surface 212 of the yoke and channel may have at least one stepped or sloped transition surface to provide the abutment surface 121, 221 as described above.

[0090] In yet another form, the stepped or sloped transition surface can extend from the lower surface 114, 212 of the yoke and channel around the upper surface 113, 211 and rear surface 112, 213. Alternatively, the stepped or sloped transition surface can be formed on the lower surface 114, 212 and rear surface 112, 213 of the yoke and channel, or on the lower surface 114, 212, rear surface 112, 213, and upper surface 113, 211 of the yoke and channel.

[0091] In one form, as shown in Figures 5, 7, 8, 13, 15, and 17, the upper surface 113 and / or lower surface 114(s) of the yoke can be configured to provide a pair of abutment surfaces 121 that slope inwardly toward each other in a direction from the front surface 111 to the back surface 112 of the yoke. As shown in Figures 4, 5, 14, 15, and 17, the abutment surfaces 221 of the yoke channel 210 can optionally be positioned at a corresponding slope relative to the upper surface 211 and / or lower surface 212(s) of the channel.

[0092] In this configuration, as shown in Figures 13 and 14, the minimum distance W between the abutment surfaces 121 of the yoke should be less than the maximum distance W1 between the abutment surfaces 221 of the yoke channel or frame. In this configuration, to fit the yoke 100 into the yoke channel 210, the yoke 100 is stretched so that the middle region 110c of the yoke is longer than the middle region 210c of the channel. After the stretched yoke 100 is fitted into the channel 210, the yoke can be released to its unstretched state. When the yoke 100 contracts to its unstretched state, the abutment surfaces 121 of the yoke contract toward the abutment surfaces 221 of the yoke channel 210, clamping the abutment surfaces 221 under tension and holding the yoke in place within the channel 210.

[0093] As will be appreciated, when the yoke 100 is fitted within the yoke channel 210, the stepped or angled profiles of the abutment surfaces 121, 221 of the yoke and yoke channel should be substantially consistent in angle and position.

[0094] The engagement member(s) 120 of the yoke and the retention member(s) 220 of the frame 2200 can each form a hinge point about which at least the end of the yoke 100 can bend so that when the yoke is attached to the headgear front straps 3130, the angle of each front strap can conform to the patient's physiology. For example, the abutment surfaces 121, 221 of the yoke and yoke channel can each form a hinge point about which at least the end of the yoke 100 can bend to form a comfortable respiratory mask system 1000 that fits well on the patient's face.

[0095] In some forms, the yoke 100 can be configured to provide one or more guides 118, such as guide surfaces, configured to abut one or more corresponding guides, such as guide surfaces 218, of the frame 210, to help the patient accurately position the yoke 100 in the frame 210. For example, the guide surfaces 118, 218 can include tapered leads on the surfaces of the yoke 100 and the yoke channel 210. In some forms, the guide surfaces 118, 218 can also act as abutment surfaces 121 / 221 to help retain the yoke 100 within the yoke channel 210, as described above. For example, the yoke 100 can include one or more shoulders 119, as described above, and the yoke channel 210 can include a substantially corresponding profile. One or more surfaces of the shoulders 119 of the yoke and yoke channel can form guide surfaces 118, 218 that can help the patient guide the yoke into the correct position within the yoke channel.

[0096] In some embodiments, the yoke and frame each preferably include at least two guide surfaces, preferably one guide surface at or near each side region of the yoke and frame.

[0097] At least one guide / guide surface 118 is preferably provided on the back surface 112 and / or top surface 113 and / or bottom surface 114 of the yoke. Similarly, at least one corresponding guide / guide surface 218 may be provided on the back wall 213 and / or top wall 211 and / or bottom wall 212 of the yoke channel. Additionally or alternatively, at least one guide / guide surface may be located on the frame 2200 outside the yoke channel.

[0098] In one form, the yoke can include one or more protrusions extending from the rear and / or top and / or bottom surfaces of the yoke, and each of the protrusions can include at least one guide surface configured to abut a corresponding guide surface on the frame.

[0099] Guide surface 118 of yoke 100 can be substantially perpendicular to adjacent surfaces 112, 113, 114 of yoke body 110, or can be inclined at an angle between 0 and 90 degrees from the adjacent surfaces. For example, if guide surface 118 is located on top surface 113 of the yoke, guide surface 118 can be inclined at an angle between 0 and 90 degrees relative to top surface 113. Similarly, guide surface 218 of yoke channel 210 can be substantially perpendicular to adjacent surfaces of the yoke channel, or can be inclined at an angle between 0 and 90 degrees from the adjacent surfaces of the yoke channel 210.

[0100] In one form, an overmolding may be located at or near each end 115 or side region 110 a, 110 b of the yoke. One or more edges of the overmolding may form one or more guide surfaces 118.

[0101] Regardless of the configuration of guide / guiding surfaces used, it is preferable that the guide surface(s) 118 of the yoke 100 substantially correspond to the guide surface(s) of the frame 2200 so as to accurately guide the yoke 100 into the yoke channel 210.

[0102] The guide / guiding surfaces 118, 218 provide indicators that can assist the patient in properly centering and aligning the yoke 100 within the channel 210. The indicators provided by the guide surfaces 118 can be particularly useful when the guide surfaces are provided on shoulders 119, 216 of the yoke and yoke channel, each of which has a substantially right-angled, stepped profile. This is because it is less likely for the patient to misalign when the shoulders 119, 216 have a right-angled angle. In some forms, the yoke 100 and channel 210 can be configured such that when the yoke 100 is mated into the channel 210, contact between the yoke and channel guide surfaces 118, 218 can provide tactile feedback to the patient that the yoke has been properly aligned and retained within the yoke channel.

[0103] 17, the yoke front surface 111 is preferably smooth and can be configured to be substantially flush with the frame front surface 2211 when the yoke 100 is properly fitted within the yoke channel 210. In this configuration, the flushness of the yoke and frame front surfaces 111, 2211 can provide a useful indication to the patient that the yoke 100 is correctly positioned within the channel 210.

[0104] In one form, substantially the entire body of the elastomeric yoke 100 can be elastic. In yet another form, only a portion of the yoke 100 is elastic. For example, only a portion of the yoke 100 can be formed from an elastomeric material.

[0105] In one form, as shown in FIG. 15 , the yoke 100 includes a stretchable middle region 110c comprising an elastomeric material and rigid or semi-rigid side regions 110a, 110b. In one form, at least some portions of the yoke's side regions 110a, 110b can be substantially rigid to provide additional stability to the yoke 100 and enhance engagement between the yoke 100 and the frame 2200. The substantially rigid portions of the yoke can provide improved structure and stability to the headgear front straps 3130 while maintaining flexibility due to the flexibility of the connection with the elastomeric middle region 110c, allowing for variable angle adjustment of the front straps 3130, as shown in FIGS. 17 and 29 . In some forms, the side regions 110a, 110b can each include a washer box housing 102 for holding a washer mechanism used in the automatically adjustable headgear system 3000, as described above.

[0106] In one form, the substantially rigid portion of the yoke can be configured to provide tactile feedback to indicate to the patient that the yoke 100 is properly seated within the yoke channel 210. The tactile feedback can be in the form of, for example, a clicking noise or a tactile click or engagement sensation.

[0107] The elastomeric nature of the yoke 100 allows the yoke to be manipulated (such as by stretching the yoke longitudinally) to fit within the yoke channel 210 and to hold the yoke in place within the channel 210.

[0108] One process for fitting one form of elastomeric yoke 100 into yoke channel 210, as shown in FIGS. 16A-16C, includes the following steps. 1. Press the first end 115a of the yoke 100 into the corresponding first end of the yoke channel 210. If the yoke includes a shoulder 119 and an abutment surface 121 that may be formed on the yoke shoulder 119, the process of fitting the elastomeric yoke 100 into the yoke channel 210 may also include aligning the first abutment surface 121a of the yoke first shoulder 119a to abut the first abutment surface 221 of the corresponding first shoulder 216a of the yoke channel 210. As shown in FIG. 16B, frictional forces should now hold the first end of the yoke 100 within the channel 210. 2. Wrap the free second end 115b of the yoke 100 across the front opening of the yoke channel 210 and onto the other side of the frame 2200. 3. Pull the free second end 115b of the yoke 100 laterally away from the frame 2200 to stretch the yoke 100 so that the second abutment surface 121b of the yoke is closer to the second end of the yoke channel 210 than the second abutment surface 221b of the yoke channel 210. 4. Push the second end 115b of the yoke 100 into the second end of the yoke channel 210 and release the yoke 100. When the yoke is released, the tension on the yoke is reduced, causing the yoke to contract and the second abutment surface 221b of the yoke 100 to clamp against the second abutment surface 221b of the yoke channel 210, as shown in FIG. 16C.

[0109] The yoke 100 should now be retained within the channel 210, securing the frame 2200 to the headgear 3000. The free ends of the yoke 100 protrude from the lateral ends 215a, 215b of the yoke channel 210 and can be attached to the free ends of the headgear front straps 3130.

[0110] In at least one embodiment, one process for fitting the elastomeric yoke 100 into the yoke channel 210 includes: holding or forcing the first end 115a of the elastomeric yoke 100 into the corresponding first end 215a of the yoke channel 210; applying tension to the yoke 100, such as by longitudinally stretching the yoke, to change at least one dimension, shape, and / or configuration of the yoke; placing or forcing the yoke 100 into position within the yoke channel 210; Releasing the tension and engaging the yoke 100 with a retaining member 220, such as an abutment surface 221 or one or more walls of the yoke channel.

[0111] In at least one embodiment, at least one size, shape, and / or configuration of the yoke 100 is a change in yoke cross section or yoke length.

[0112] In at least one embodiment, applying tension to yoke 100 to change at least one dimension, shape, and / or configuration of the yoke results in an elongation and / or lengthening of the yoke. In such an embodiment, a distance W between first abutment surface 121 a and second abutment surface 121 b of yoke 100 can be greater than a distance W1 between first abutment surface 221 a and second abutment surface 221 b of yoke channel 210.

[0113] In at least one embodiment, releasing the tension on the yoke 100 contracts or reduces the length of the yoke such that the second abutment surface 121b of the yoke abuts the second abutment surface 221b of the yoke channel 210. In at least some configurations, the first and second abutment surfaces 121a and 121b of the tensioned yoke apply a compressive force to the first and second abutment surfaces 221a and 221b of the yoke channel 210, thus retaining the yoke 100 within the yoke channel 210.

[0114] In at least one embodiment, the yoke channel 210 has a "C-shaped" cross-section. Applying tension to the yoke 100 to change at least one dimension, shape, and / or configuration of the yoke reduces the height of the yoke 100 below the height H1 of the "C-shaped" cross-section yoke channel opening 214.

[0115] In at least one embodiment, applying tension to the yoke 100 to change at least one dimension, shape, and / or configuration of the yoke allows the yoke to pass through the yoke channel opening 214 when under tension.

[0116] In at least one embodiment, the step of releasing the tension on the yoke 100 and engaging the yoke with the retaining member 220 returns the height of the yoke 100, which was stretched forward, to its original state, and then the upper surface 113 and lower surface 114 of the yoke press against the upper surface 211 and lower surface 212 of the yoke channel, retaining the yoke 100 within the yoke channel 210.

[0117] 18-27, an elastomeric yoke 100 can include a body 110 comprising an elongated strip of elastomeric material. The yoke can be formed at least partially, and preferably entirely, from an elastomeric material, such that the elastomeric portion of the yoke 100 can be configured to extend longitudinally along the length of the yoke 100. In some forms, the elastomeric portion of the yoke 100 can also be configured to extend laterally along the height of the yoke 100.

[0118] Yoke 100 may also include at least an engagement member 120 in the form of a yoke opening 125 formed in the body 110 of yoke 100. Each yoke opening 125 may pass through yoke 100 from the front surface 111 to the back surface 112 of the yoke, or to a midpoint or a point between the front surface 111 and the back surface 112 of a multi-layer yoke, such as a two-layer yoke.

[0119] The one or more yoke openings 125 may be formed in the yoke using any suitable method, such as, for example, using a punch to form the yoke opening(s), laser cutting or blade cutting the opening(s), or three-dimensionally weaving the yoke to form the one or more openings 125 in the yoke.

[0120] Each yoke opening 125 is configured to receive a retaining member 220 of a frame 2200 of the patient interface 2000. The retaining member 220 may be a protruding arm 223, such as a post, a catch, or a hook, that protrudes from the frame and is configured to be at least partially received within the yoke opening 125. The frame may include a single retaining member 223 for engaging a single yoke opening 125. Alternatively, the frame 2200 may include two or more retaining members 223 for engaging two or more yoke openings 125. In yet another form, the yoke 100 may provide an adjustable fit by including multiple yoke openings 125 for engaging one or more retaining members 223 of the frame, as shown in FIG. 21 .

[0121] Each yoke opening 125 is configured to be positioned over a protruding arm 223 of the frame 2200, such that at least a portion of the arm 223 is retained within the yoke opening 125. The arms 223 preferably extend through the yoke opening 125 and protrude from the front surface 111 of the yoke.

[0122] In one form, the patient interface 2000 can include a pair of arms 223 projecting from the left and right sides of the frame 2200, and the yoke 100 can include at least one pair of openings 125. The distance between the openings 125 can be less than the distance between the arms 223, such that when the yoke is attached to the frame by placing the arms 223 through the openings 125, the yoke is held to the frame under tension.

[0123] 18-21 show one form of respiratory mask system 1000 including an elastomeric yoke 100 with at least one pair of yoke openings 125 for engaging a pair of protruding arms 223 on a frame 2200 of a patient interface 2000. In this form, the yoke 100 has a substantially elongated shape and is configured to extend along the length of the yoke 100 when under tension. A yoke opening 125 is provided in each side region 110a, 110b of the yoke 100.

[0124] In one form, the frame 2200 can include a yoke channel 210 located on the front surface 2211 of the frame body 2210. An arm 223 can protrude from each end 215a, 215b of the yoke channel 210. Each arm 223 preferably includes a rounded end to help guide the arm 223 through its respective yoke opening 125 without catching or tearing in the yoke. This configuration is particularly useful when the yoke is formed from a stretchy fabric.

[0125] The yoke 100 is configured to reside at least partially within the yoke channel 210 such that the upper and lower surfaces 211, 212 of the yoke channel 210 can abut or be adjacent to the respective upper and lower surfaces 113, 114 of the yoke. The yoke channel 210 helps prevent the yoke 100 from sliding upward or downward on the frame 2200. In this manner, the yoke 100 can be substantially centered on the frame 2200 to help prevent the yoke from warping relative to the frame 2200.

[0126] In another form, the yoke can be configured to press against the front face of the frame and be held to the frame under tension, and the frame does not necessarily include a yoke channel.

[0127] 18 and 20A-20C includes a pair of yoke openings 125, one located in each side region 110a, 110b of the yoke such that when the yoke is positioned along the yoke channel 210, the yoke opening 125 is located adjacent to a protruding arm 223. In one form, as shown in FIG. 20A, each yoke opening 125 is in the form of a slot, and each arm 223 is in the form of a narrow tab that protrudes through a corresponding yoke opening / slot 125 in the yoke 100.

[0128] A method for attaching the yoke 100 to the frame 2200 is shown in FIGS. 20A-20C. As a first step, the yoke 100 is positioned near the front surface 2211 of the frame. One end of the yoke 100 is then attached to the frame by pulling the yoke over the frame and the first arm 223a, so that the first arm 223a protrudes through the first yoke opening 125a, as shown in FIG. 20B. The elastomeric yoke is then stretched along the length of the yoke, pulling it across the frame 2200 and yoke channel 210, aligning the second arm 223b with the second yoke opening 125b. The tension on the yoke 100 is then at least partially released, allowing the second arm 223b to protrude through the second yoke opening 125b. The yoke is now attached to the frame as shown in FIG. 20C. When the yoke 100 is held in the frame 2200, the middle region of the yoke 100 located between the yoke openings 125a, 125b preferably remains slightly stretched under tension. In this manner, the yoke 100 is pulled taut across the frame 2200, providing a snug fit and holding the patient interface 2000 on the patient's face.

[0129] The retaining members / arms 223 and yoke openings 125 can be located in any suitable location on the frame 2200 that allows the yoke 100 to be attached to the frame 2200 in a stable position and hold the yoke under tension. For example, a pair of yoke openings can be located in the mid-region of the yoke for attachment to corresponding arms 223 located in the yoke channel 210 or the mid-region of the frame 2200.

[0130] 27, the bottom wall 212 of the yoke channel 210 can include a guide 218 that forms a tongue that extends downward from the yoke channel 210. The guide 218 helps the user accurately position the yoke 100 within the yoke channel 210 by facilitating the sliding of the yoke 100 up and into the channel 210. After the yoke 100 is properly positioned within the channel 210, the top wall 211 of the yoke channel prevents the yoke 100 from sliding further up the frame 2200.

[0131] In some configurations, the frame of the patient interface need not include a yoke channel capable of retaining the yoke. The yoke 100 can alternatively be attached to a retention member 220 formed on the front surface of the frame. For example, the arms 223 can protrude from the front surface 2211 of the frame 2200 in any suitable location. The arms 223 and corresponding yoke openings 125 in the yoke are preferably configured to hold the yoke under tension when the yoke is engaged with the arms. In one configuration, as shown in FIG. 22 , at least one arm 223 protrudes from opposite left and right sides of the frame 2200. In other configurations, two or more arms 223 can protrude from the left and right sides of the frame 2200. For example, FIG. 23 shows a frame 2200 with a first pair of lower retention members / arms 223 a, 223 b, with the arms 223 a, 223 b protruding from the left and right sides of the frame 2200. The frame 2200 also includes a second pair of upper retaining members / arms 223c, 223d, which are positioned above the lower arms 223a, 223b and project from the left and right sides of the frame 2200, respectively. In this configuration, the corresponding yoke can include a pair of upper and lower yoke openings 125. In this configuration, two yoke openings are positioned one above the other in each of the left and right side regions 110a, 110b of the yoke to engage with the respective left and right arms 223a, 223b of the frame. Alternatively, the yoke 100 can have at least one engagement opening 125 located in each side region of the yoke, as shown in FIGS. 18 and 21. Each opening 125 can selectively engage with one of the lower pair of arms 223a, 223b or one of the upper pair of arms 223c, 223d. In this configuration, the yoke and frame provide an adjustable fit for the user.

[0132] In either configuration, the yoke 100 can be attached to the frame 2200 by engaging the yoke opening(s) 125 in one side region of the yoke with the arm(s) 223 on the corresponding side of the frame, then stretching the yoke along its length, aligning the other yoke opening(s) in the other side region of the yoke with the other arm(s) on the other side of the frame, and then fitting the other arm(s) through the selected other yoke opening(s) and releasing the yoke, as shown in Figures 20A-20C.

[0133] As shown in FIG. 21, when the yoke 100 includes a series of yoke openings 125 extending along at least a portion of the length of the yoke, and the frame 2200 includes one or more arms 223, the user can select which yoke opening engages with the arm(s) in order to adjust the yoke to provide a comfortable fit.

[0134] 24-26 show a portion of the frame body 2210a and alternative forms of the yoke including engagement member / yoke openings 125 configured to engage with retention members / arms 223 of the frame to attach the yoke 100 to the frame 2200. In these forms, the yoke includes at least one pocket or loop, and preferably at least two pockets or loops 129, for receiving and engaging one or more arms 223 of the frame.

[0135] In the embodiment shown in FIGS. 24 and 26 , the yoke 100 comprises a multi-layered elastomeric body. As shown, the yoke preferably comprises two fabric layers 127, 128 extending substantially along the length of the yoke. However, in other configurations, the yoke can comprise three or more fabric layers. The yoke 100 also comprises a pair of openings 125, one opening 125 located in each side region 110 a, 110 b of the yoke. Each opening 125 provides access to a pocket 129 in the yoke 100. The pocket 129 is formed by a gap 126 present between the fabric layers 127, 128. For example, if the yoke 100 comprises two fabric layers, the first inner fabric layer 127 can include a yoke opening 125 that provides access to the gap 126 formed between the first layer 127 and the second outer fabric layer 128. If the yoke comprises three or more fabric layers, the yoke openings may be formed only in the inner layer to provide access to the pocket gaps between the inner layer and adjacent layers, or may be formed through two or more fabric layers to provide access to the pocket gaps between the deeper layers of the yoke. In these configurations, the fabric layers preferably extend substantially along the length of the yoke.

[0136] Alternatively, only some regions of the yoke, such as the side regions, may include multiple fabric layers. Preferably, two fabric layers are provided in each side region 110a, 110b. For example, in the embodiment shown in FIG. 25, the yoke 100 may include a first elastomeric fabric layer 128 extending substantially across the length of the yoke. A second, inner fabric layer 127 is provided in each side region 110a, 110b of the yoke, thus providing each side region with two fabric layers. A space or gap 126 is provided between the two layers 127, 128 in each side region 110a, 110b. Each gap 126 is accessible by at least one yoke opening 125, which may be formed through the inner fabric layer. Alternatively, as shown, the yoke opening 125 may be provided at the inner edge of the inner fabric layer 127. For example, a gap 126 can be formed between the two layers 127, 128 at a point near the middle region 110c of the yoke where the inner layer 127 terminates. This gap 126 can be created by sewing, bonding, welding, or otherwise attaching the top and bottom edges of the two fabric layers 127, 128 together, but leaving the inner edge of the inner fabric layer 127 unattached to the other fabric layer 128. Alternatively, other configurations for creating a yoke opening 125 at the edge of each inner layer can be used, such as 3D knitting the yoke to have two or more fabric layers 127, 128 in the side regions 110a, 110b. The yoke opening 125 provides access to the inner gap 126 for forming a pocket 129 in the yoke.

[0137] In yet another configuration, as shown in FIG. 25 , the yoke 100 can include two or more fabric layers 127, 128 at two or more locations along the length of the yoke. In this configuration, the yoke 100 can include a first fabric layer 128 that extends substantially along the length of the yoke. Loops 130 of the second fabric layer 127 can also be provided in the side regions 110 a, 110 b or along the length of the yoke 100. For example, the yoke can include a pair of loops 130, one loop 130 located in each side region 110 a, 110 b of the yoke. Alternatively, the yoke 100 can include two or more loops 130 in each side region 110 a, 110 b, or multiple loops 130 extending across the length of the yoke 100, to provide multiple attachment / anchor points that engage one or more retention members 223 to allow for an adjustable fit. As mentioned above, the inner edges of the loops 130 can provide yoke openings 125 that provide access to the gap between the looped fabric 127 and the first fabric layer 128. The loops 130 act similarly to pockets 129 in that each loop can receive and retain a retention member 223 between the two fabric layers 127, 128.

[0138] Each pocket 129 or loop 130 is configured to receive a corresponding retention member 223 therein. In this configuration, the yoke can be attached to the frame whether or not the frame includes a yoke channel. The fabric layers may be made of the same or different materials. For example, the inner fabric layer may be softer than the outer layer to provide additional comfort to the user.

[0139] The pockets 129 / loops 130 may be formed by any suitable method. In one form, the yoke 100 may be three-dimensionally knitted to include the pockets or loops. In another form, the yoke 100 may include an inner material layer 127 and an outer material layer 128 joined together, such as by bonding, welding, stitching, welding, or other methods. The yoke openings 125 may be formed in the inner layer 127, and the pockets may be formed between the inner layer 127 and the outer layer 128. Each pocket 129 may include an open area between the inner layer 127 and the outer layer 128 of the yoke 100, as shown in FIGS. 24-26. The open areas may be located adjacent to each yoke opening 125 and between the yoke opening and the end 115 of the yoke.

[0140] In each of these embodiments, the frame and yoke can be sized so that when the yoke is attached to the frame, the intermediate region of the yoke (i.e., the region between the retaining members) is held under tension. The tension helps hold the yoke in place relative to the frame. To accomplish this, the yoke openings can be spaced apart a distance less than the distance between the retaining members / arms.

[0141] One method of attaching a yoke to a patient interface involves a user positioning a first engagement member located at or near a first end of the yoke adjacent to a first retention member of a patient interface, such as the frame of a mask assembly. The first retention member can be located on a first side of the patient interface, such as the left side. The first retention member is engaged 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, and then substantially aligns a second engagement member located at or near a second opposite end of the yoke with a second retention member located on a second side, such as the right side, of the patient interface. The user then engages the second engagement member with the second retention member while holding the yoke under tension. The yoke is then released, at least partially relieving the tension on the yoke. However, it is preferred that the yoke remain under at least some tension to help hold the yoke to the patient interface.

[0142] In a more specific example of a method for attaching the yoke to the patient interface, a user presses one end of a first retaining member / arm 223 into a first yoke opening 125, hooking the arm 223 around the yoke opening to form a first anchor point. The user then stretches and deforms the yoke, placing it under tension, and the user snaps the second yoke opening 125 around the other / second retaining member 223. The user then releases the yoke, relieving at least some of the tension on the yoke. If, when the yoke is in its natural, unstretched state, the distance between the yoke openings of the yoke is less than the distance between the first and second retaining members on the left and right sides of the patient interface, the yoke will remain under tension while attached to the patient interface. The tension in the yoke helps hold the yoke securely in place relative to the patient interface.

[0143] In yet another form, the frame 2200 can include a single retaining member 220. The retaining member preferably defines a protruding arm 223 that is substantially centrally located on the front surface 2211 of the frame body 2210. The corresponding yoke 100 can include an engagement member in the form of a yoke opening 125 that is substantially centrally located along the length of the yoke 100. The frame 2200 may or may not include a yoke channel 210 for receiving the yoke 100.

[0144] For example, as shown in FIGS. 27, 28A, and 28B, the frame can include a yoke channel 210 having an upper surface 211, a lower surface 212, and a rear surface 213, as described above. A retaining member 223, such as an arm, anchor point, or post, can protrude from the rear surface 213 in an intermediate region of the yoke channel 210. The retaining member / arm 223 can include a stem 228 and a capped end 229 that is wider, longer, or both wider and longer than the stem 228. For example, the end 229 of the arm 223 can include a peripheral flange that protrudes outward beyond the periphery of the stem 228. In one form, the width of the arm 223 extends along a portion of the length of the yoke channel 210, as shown in FIG. 27, giving the arm a substantially elongated width. In another form, the arm 223 can be mushroom-shaped or any other suitable shape to engage the yoke opening 125.

[0145] 27, an elastomeric yoke 100 having a substantially centrally located yoke opening 125 can be provided for attachment to a frame 2200. The yoke 100 can be configured to extend along the length of the yoke 100 such that the yoke opening 125 can fit over the capped end of the arm 223 to retain the axle of the arm 223 within the yoke opening 125.

[0146] 28A and 28B show a method of attaching the yoke 100 to a patient interface. In this method, a user positions the engagement member of the yoke adjacent to the retention member of the patient interface, such as the frame of a mask assembly. The user then hooks the engagement member around the retention member to hold the yoke in place.

[0147] More specifically, a user can push one end of elongated retaining member / arm 223 into yoke opening 125, hooking the arm around the yoke opening to form a first anchor point. The user then stretches and deforms the yoke, placing the yoke under tension, and the user stretches yoke opening 125 to reach around the other end of elongated retaining member 223. The user then releases the yoke, relieving at least some of the tension on the yoke. The yoke returns to substantially its natural, unstretched state, in which yoke opening 125 is smaller than capped end 229 of arm 223 and therefore cannot be separated from arm 223 without stretching and pulling over capped end 229.

[0148] In other forms, the yoke may be attached to other areas of the patient interface, for example, the yoke may be attached to one or more retaining members of a seal of the patient interface.

[0149] The elastomeric material of the yoke 100 allows the yoke 100 to bend substantially horizontally and / or substantially vertically. For example, the yoke 100 can bend toward or away from the frame body 2210 and the patient's face. Correspondingly, the yoke 100 allows the connection between the headgear 3000 and the frame 2200 to be flexible, thereby allowing the ends of the front straps 3130 to bend toward or away from each other. The dashed lines in FIG. 29 show how the ends 115 of the yoke 100 can bend substantially horizontally, while the arrows in FIG. 17 show how the ends 115 of the yoke 100 can bend substantially vertically. Each side of the yoke 100 can bend independently of the other side, such that a force applied to one side is decoupled from the other side. This means that the yoke 100 can be particularly suitable for patients who sleep on their side, as it can flex when one side of the yoke 100 is pressed against a pillow without breaking the seal between the frame seal 2100 and the patient's face, for example.

[0150] The flexibility of the elastomeric yoke 100 also allows the yoke to conform to different facial shapes and widths. For example, the ends 115 of the yoke can be flexible or can be attached directly or indirectly to flexible elastomeric connectors 101, 3140, so that the ends 115 of the yoke or the ends of the yoke and connector assembly can flex toward or away from each other, or up or down relative to the mid-region 110c of the yoke. This flexibility prevents the yoke ends 115 or connectors 101, 3140 from digging into the patient's face.

[0151] The flexible yoke 100 can also improve the stability of the patient interface 2000 on the patient's face. For example, if the yoke 100 includes protruding rigid ends 115 and the ends of the yoke get caught in bedding, a bending moment can be created, potentially causing the patient interface 2000 to rotate on the patient's face. By providing a flexible yoke 100, the ends 115 of the yoke can bend and move independently from the middle region 110c of the yoke. Thus, even if the yoke ends 115 get caught in bedding, the flexibility of the yoke 100 allows the patient interface 2000 to remain in a desired position on the patient's face.

[0152] The elastomeric yoke 100 can also be relatively easily coupled to the frame 2200. For example, if a respiratory mask system includes the yoke 100 and the frame 2200 having a yoke channel 210 for receiving the yoke, the yoke 100 and yoke channel 210 can be configured to provide a tactile or haptic feedback to the patient when the yoke 100 is properly fitted within the channel 210.

[0153] The soft feel of the elastomeric material of the yoke 100 also makes the yoke 100 and headgear 3000 more comfortable to handle and may imply that the entire headgear can be washed.

[0154] The elastomeric yoke allows the headgear assembly of the respiratory system to be easily removed from the patient interface / mask assembly without requiring laborious removal of components of the headgear assembly and mask assembly. In some forms, a user can remove the yoke and headgear from the mask assembly with one hand. Once removed, the yoke and headgear assembly can be cleaned. If the yoke and headgear are made entirely from fabric, the headgear assembly with the yoke can be easily cleaned without having to worry about sensitive non-fabric components.

[0155] The simple nature of the elastomeric yoke of the present invention provides a minimally complicated and aesthetically pleasing appearance to the headgear that holds the yoke. The headgear can also be lightweight.

Claims

1. 1. A headgear assembly for a patient interface of a respiratory system, the headgear assembly comprising: at least one strap for wrapping around a user's head; and a yoke coupled to an end of the at least one strap, the yoke being at least partially formed from an elastomeric material; and the yoke comprising at least one engagement member configured to be attached to at least one retention member of the patient interface.

2. 2. The headgear assembly of claim 1, wherein the headgear assembly comprises a back strap connected to a pair of front straps, the yoke comprising an intermediate region located between two side regions terminating at ends of the yoke, the ends of the yoke configured to connect to the free ends of the front straps.

3. 3. The headgear assembly of claim 1 or 2, wherein the yoke is formed entirely from an elastomeric material.

4. A headgear assembly as described in any one of claims 1 to 3, wherein the yoke has an upper surface, a lower surface, a front surface, and a rear surface, and the upper surface and / or the lower surface and / or the rear surface of the yoke are provided with a pair of stepped regions, each step region separating the middle region from each side region.

5. 5. The headgear assembly of claim 4, wherein each stepped region includes a transition wall separating the middle region from the side regions, each transition wall forming an abutment surface configured to align with a corresponding abutment surface in a channel of a frame of a patient interface.

6. The headgear assembly of claim 5 , wherein the abutment surfaces face each other and slope outwardly toward the distal end of the yoke.

7. The headgear assembly of claim 2 , wherein the side regions of the yoke are substantially rigid.

8. The headgear assembly of claim 7 , wherein each side region of the yoke includes a washer box housing.

9. The headgear assembly of claim 8 , wherein the yoke includes at least one collection chamber for receiving one or more filaments from an automatically adjustable headgear system.

10. A headgear assembly according to any one of claims 1 to 7, wherein the yoke has ends, each end being connected to a headgear connector assembly, the headgear connector assembly comprising a washer box housing and a connector configured to connect to a front strap of the headgear.

11. A headgear assembly according to any preceding claim, wherein the yoke has ends, each end connected to a connector configured to connect to a front strap of the headgear assembly.

12. A headgear assembly according to any preceding claim, wherein the yoke has substantially rounded edges.

13. A headgear assembly according to any preceding claim, wherein the engagement member of the yoke comprises an aperture, and the retaining member comprises an arm configured to be received within the aperture.

14. A breathing system comprising a patient interface comprising a mask assembly and a headgear assembly according to any one of claims 1 to 13.

15. 15. The respiratory system of claim 14, wherein the mask assembly comprises a seal and frame assembly, the frame having a front and a back, the front of the frame comprising a yoke channel extending laterally across the frame, the yoke channel configured to receive the yoke of the headgear assembly.

16. 16. The breathing system of claim 15, wherein the yoke channel comprises an upper surface, a lower surface, and a rear surface, the edges of the upper and lower surfaces each forming a lip defining a front opening of the channel, the lips of the channel projecting toward each other such that the maximum distance between the lips is less than the maximum distance between the upper and lower surfaces of the channel.

17. 17. A respiratory system according to claim 16, wherein the upper and lower surfaces of the channel are substantially concave along at least a portion of the length of the channel, giving the channel a substantially C-shaped cross-section.

18. A breathing system according to any one of claims 14 to 17, wherein the yoke channel comprises one or more retaining members configured to retain the yoke within the channel.

19. 20. The respiratory system of claim 18, wherein each retention feature comprises a tab that intersects the yoke channel and projects at least partially forward of the yoke when the yoke is positioned within the channel.

20. 15. The respiratory system of claim 14, wherein the mask assembly comprises a frame having a front and a back, one or more retention members projecting from the front of the frame for engaging with one or more engagement members of the yoke.

21. 18. A breathing system according to any one of claims 14 to 17, wherein the mask assembly comprises a frame having a pair of arms projecting from left and right sides of the frame, and the yoke comprises at least one pair of openings, the distance between the openings being less than the distance between the arms.

22. 1. A method of attaching a yoke to a patient interface, comprising: 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 retain the yoke to the patient interface at a first fastening point; pulling the yoke against the first anchor point until a second engagement member located at or near a second end of the yoke is substantially aligned with a second retention member located on a second side of the patient interface; engaging the second retention member with the second engagement member while holding the yoke under tension; releasing the yoke; A method comprising:

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