Patent Description:
Respiratory interfaces or masks are used to provide respiratory gas or gases, such as air in CPAP therapy, including in for example VPAP and BiPAP systems, or NIV, or high flow rate therapy, for example.

Commonly a respiratory interface comprises a mask frame to which for example headgear attaches which holds the interface in position on the user's head when worn, and a seal module (sometimes also referred to as a cushion or cushion module) configured to couple to the mask frame and interface to a user's mouth and/or nose to deliver respiratory gases to the user. A respiratory interface may comprise a nasal, oral, or oro-nasal (also referred to as full face) seal module. In turn an interface may be an indirect interface which covers the nose, mouth, or both, or a direct interface such as an interface comprising nasal nozzles or pillows or similar which enter into and seal against or within the nares of the wearer or cannula which non-sealingly enter the nares. The seal module can be formed entirely or almost entirely of a soft material which is comfortable against the wearer's face, such as commonly a silicone material, or the seal module may comprise a rigid or semi-rigid frame interfacing part formed of a rigid or semi-rigid material and which couples to the mask frame and a seal part formed of a relatively soft material.

Typically the seal module couples mechanically to the mask frame via a friction fit, snap fit, or other interference fit, of formations on the seal module and mask frame to one another. The seal module couples detachably to the mask frame so that it can be removed for cleaning or so that different sizes of seal module may interface with the mask frame. Prior art arrangements are known from <CIT>, which discloses a respiratory mask having a magnetically supported cushion, <CIT>, which discloses a patient interface, and <CIT>, which discloses a magnetic coupling assembly.

Subject-matter referred as embodiments, arrangements, aspects and/or disclosures which do not fall under the scope of the claims are not part of the invention.

In broad terms in one aspect the invention comprises a respiratory interface comprising:.

In broad terms an arrangement comprises a seal module for a respiratory interface, the seal module configured to couple to a mask frame and interface to a user's mouth and/or nose to deliver respiratory gases to the user, and comprising at least one magnet or ferrous part associated with the seal module to magnetically couple the seal module to the mask frame.

In one form the respiratory interface may include magnets associated with the seal module provided at left and right sides of the seal module and magnets associated with the mask frame are provided at left and right sides of the mask frame. Preferably, magnets associated with the seal module or mask frame are provided to the seal module or mask frame with movement in a direction in which the seal module and mask frame interface so that on offering together the seal module and mask frame magnets associated with the seal module or mask frame move toward the magnets associated with the mask frame or seal module. Preferably the seal module is formed of a soft material. The seal module may comprise a frame interfacing part formed of a rigid or semi-rigid material and which couples to the mask frame and a seal part formed of a relatively soft material. The seal module may be an indirect or direct nasal seal module or an oro-nasal seal module.

In broad terms another arrangement comprises a seal for a respiratory interface, the seal module configured to interface to a user's mouth and/or nose to deliver respiratory gases to the user, and comprising at least one magnet or ferrous part associated with the seal to magnetically hold a first part of the seal in position relative to another part of the seal or a part of a frame of the respiratory interface. Preferably multiple magnets or ferrous parts associated with the seal or a frame to magnetically hold a first part of the seal in multiple selectable adjustment positions of the first part of the seal relative to another part of the seal or a part of a frame of the respiratory interface. Preferably, the seal comprises a frame interfacing part formed of a rigid or semi-rigid material and which couples to a mask frame and a seal part formed of a relatively soft material. In one form the magnet or magnets comprise particulate magnetic material, that is preferably embedded in soft material of the seal module.

In broad terms another arrangement comprises a respiratory interface comprising a mask frame and a seal as above.

In broad terms another arrangement comprises a respiratory interface and/or headgear, comprising a first part and a second part which in use are coupled together, wherein at least one of the first part and second part comprise a magnet or magnets for magnetic coupling of the first part and second part together which comprise a particulate magnetic material embedded in the first part and/or second part. In one form the particulate magnetic material is embedded in the first part and/or second part by moulding. Preferably, one of the first part and second part is a seal module and the particulate magnetic material is embedded in soft material of the seal module.

In broad terms another arrangement comprises a respiratory interface comprising: a first seal part configured to interface to one of a user's mouth and nose to deliver respiratory gases to the user, and a second seal part configured to interface to the other of a user's mouth and nose to also deliver respiratory gases to the user, and a magnetic coupling system arranged to magnetically couple the first and second seal parts to one another or to a common mask frame and so that at least one of the first and second seal parts is detachable from the other or from common mask frame.

Preferably, at least one magnet associated with one of the first or second seal parts or the mask frame and at least one magnet associated with another of the first or second seal parts or the mask frame are provided to the seal parts or mask frame such that they attract when the seal parts are coupled to each other or to the mask frame in a predetermined correct orientation and repel in any orientation other than said predetermined correct orientation.

In broad terms another arrangement comprises a respiratory interface comprising:.

In broad terms another arrangement comprises a magnetic coupling system arranged to magnetically couple a conduit to a fitting or another conduit, comprising a first annular part configured to receive a second annular part over the first annular part, comprising:.

In broad terms another arrangement comprises headgear for a respiratory interface, comprising:.

In broad terms another arrangement comprises a headgear for a respiratory interface, or headgear and a respiratory interface together, comprising:.

In broad terms another arrangement comprises headgear for a respiratory interface, or headgear and a respiratory interface together, comprising: a first headgear part comprising a first magnet at or towards an end thereof, a second headgear part comprising a second magnet at or towards an end thereof, or a mask comprising a second magnet on a part of the mask, arranged to magnetically couple the first headgear part to the second headgear part or mask, and a decoupling tool comprising a third magnet and insertable between the first and second magnets when the first headgear part and the second headgear part or mask are coupled, to at least assist in de-coupling same.

In a further form headgear for a respiratory interface may be provided, or headgear and a respiratory interface together, comprising: a first headgear part having an inflatable portion, a second headgear part, a magnetic coupling system arranged to magnetically hold the first and second headgear parts together, a decoupling mechanism comprising a pump associated with the inflatable portion, wherein activation of the pump causes the inflatable portion to inflate, causing the first and/or second part to move away from the other part.

Preferably, the second headgear part has an inflatable portion and activation of the pump causes the inflatable portion to inflate. In one form the parts move away from each other by one or both of the parts moving from a curved configuration to a relatively straight configuration. A substantial portion of each or both of the first and second headgear parts may be inflatable. Preferably the first headgear part and the second headgear part overlap when held together by the magnetic coupling system.

In a further form the respiratory interface or headgear according to any one of the previous aspects or arrangements comprises a magnet or magnets comprising a segment of solid (non-particulate) magnetic material or a magnet or magnets comprising particulate magnetic material. Preferably the particulate magnetic is material embedded in a part of the respiratory interface or headgear. This may comprise a mask frame and a separate seal module. Preferably the seal module comprises a frame interfacing part formed of a rigid or semi-rigid material and which couples to a mask frame and a seal part formed of a relatively soft material. In one form the interface may comprise an indirect nasal seal or direct nasal seal or an oro-nasal seal. A respiratory interface or headgear having features according to any aspect described herein may comprise any features/integers in combination.

Interfaces of the invention may be used in continuous positive airway pressure (CPAP) systems for providing a heated and optionally also humidified air stream to a user (U) through the interface worn by the user, or alternatively in other forms of respiratory systems, such as for example VPAP (Variable Positive Airway Pressure) systems, BiPAP (Bi level Positive Airway Pressure) systems, or in non-invasive ventilation (NIV), or high flow rate (not necessarily also above ambient pressure) therapy, for example, and are described herein generally with reference to CPAP therapy by way of example only. The interfaces may be useful particularly for CPAP therapy at air pressures in the range about <NUM> to about <NUM> H<NUM>O. However the interfaces may also be used in in systems or therapy in which the air or other gases are not heated and/or humidified.

In this specification the term "comprising" means "consisting at least in part of". When interpreting a statement in this specification and claims that includes "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted similarly.

Embodiments are described with reference to the accompanying drawings, by way of example and without intending to be limiting, in which:.

Interfaces to which this disclosure relates can be used in the field of respiratory therapy. In some embodiments, the interfaces may have particular utility with forms of positive pressure respiratory therapy. For example, an interface can be used for administering continuous positive airway pressure ("CPAP") treatments, variable positive airway pressure ("VPAP") treatments and/or bi-level positive airway pressure ("BiPAP") treatments. The interface can be compatible with one or more different types of suitable CPAP systems.

<FIG> show a respiratory interface comprising frame <NUM> and seal module <NUM>. The frame <NUM> can be rigid, substantially rigid or semi-rigid. For example, the frame can be at least partially made of a metal or rigid plastic, such as acrylic or polycarbonate or high-density polyethylene. The seal module <NUM> is a separate component from the frame <NUM> and couples to the user-facing side of the frame to assemble the interface for use, and is detachable from behind the frame for cleaning of the seal module for example. In the arrangement shown in <FIG> and <FIG> the seal module covers a user's mouth and nose to deliver respiratory gases to the user. Alternatively the seal module may cover the nose only or mouth only, or comprise nasal nozzles or pillows or similar which enter into and seal against or within the nares of the wearer, or cannula which non-sealingly enter the nares. In further arrangements the seal module may cover the mouth and also comprise nozzles or pillows which enter the nares.

In the arrangement shown the interface comprises an elbow <NUM> by which an air delivery conduit couples to the interface, and in the arrangement shown the elbow couples to the frame <NUM> via a ball joint but alternatively the elbow may swivel about one axis only, or the air delivery conduit may couple directly to the interface without an elbow. The seal module <NUM> comprises an aperture into the seal module by which respiratory gases (hereinafter, air) enter the seal module from the elbow or conduit direct.

At least the part of the seal module <NUM> which contacts the user's face is formed of a soft material, such as a silicone material for example, to comfortably seal against the user's face. All or substantially all of the seal module may be formed from this material, which may be thicker towards and where the seal module interfaces with the frame to provide some structural support to the thinner face contacting part of the seal module, or alternatively as in the arrangement shown a forward part of seal module ie a frame interfacing part or shell part <NUM>, may be formed of a rigid material such as acrylic or polycarbonate or high-density polyethylene, or a semi-rigid material (while seal part <NUM> which contacts the user's face is formed of the softer material). Alternatively again only a smaller part or parts of the seal module which connect the seal module to the frame may be formed of a rigid or semi-rigid material, such as a ring part around the air entry aperture into the seal module for example. Seal part <NUM> may be overmoulded, welded to shell part <NUM> or may attach to part <NUM> by permanent or detachable clipping including snap fitting, for example.

Arrangements of the interface may comprise one or more vent holes for expelling exhaled air. One or more vent holes may be provided in the seal module or elbow <NUM> for example.

Arrangements of the interface may comprise an anti-asphyxia valve, in an elbow for example or elsewhere on the interface. Headgear generally indicated at <NUM> holds the interface in position on the user's head when worn. In the arrangement shown the headgear comprises left and right lower straps <NUM> and left and right upper straps <NUM>, which extend from a rear part <NUM> of the headgear, along the left and right sides of the user's head below and above the ears to couple to the frame <NUM> of the interface. The upper straps <NUM> couple to the top of a forehead support <NUM> of the frame <NUM>, but in other arrangements may extend downwardly from above the ears, below the eyes, to connect to a frame not having a forehead support. Optionally the headgear may also comprise a top strap such as a crown strap <NUM> or forehead strap, and/or an occipital loop, and the headgear may be in various other forms. For example headgear may comprise only a rear strap and a crown or forehead strap, and a single strap along either side of the user's head or face to the mask. The rear part <NUM> of headgear can comprise a generally annular component comprising a back strap, a top strap and a pair of upright straps. The headgear may be formed from parts attached together, using for example ultrasonic welding, or may be a single unitary pieces (not formed from separate attached parts). The length of one or more of the headgear straps may be adjustable. Headgear is commonly formed at least in part from a soft flexible material such as a cloth covered foam material such as BREATHE-O-PRENE® material for example, but may be formed from any other suitable material, such as in whole or part from a semi-rigid plastics material for example which may optionally be covered with a softer material. The headgear may be formed from parts attached together, using for example ultrasonic welding, or may be a single unitary piece (not formed from separate attached parts). The headgear may comprise one or more rounded edges, formed in any suitable manner, for example by applying heat and pressure to edges of the headgear. The headgear assembly can be configured to directly couple to the mask assembly without the use of clips. In some configurations, the pair of upper side straps and the pair of lower side straps can comprise ends with fasteners that loop through headgear attachments on the mask assembly and the fasteners can be configured to couple with complementary fasteners on the sides of the pair of upper side straps and the pair of lower side straps. Further disclosure regarding headgear is at the end of this description.

In the arrangement shown the seal module <NUM> couples to the mask frame <NUM> at or around aperture <NUM> in the front of the seal module through which air enters the seal module in use. When the seal module <NUM> is correctly fitted to the mask frame <NUM> seal module aperture <NUM> aligns with a corresponding aperture <NUM> through the mask frame from the elbow or conduit, through which air passes to the seal module. In the arrangement shown aperture <NUM> through the mask frame also defines the socket in the mask frame which receives the ball joint end of elbow <NUM>. A magnetic coupling system couples the seal module <NUM> and mask frame <NUM>, to hold the seal module on the mask frame. <FIG> is a front view of the seal module and <FIG> is a rear view of the mask frame ie shows the side of the mask frame which interfaces with the seal module. Magnets 121a, 122a, 123a and 124a are associated with rim portion <NUM> around of aperture <NUM> through the seal module. For example the magnets may be embedded in this rim portion during plastic moulding of the seal module. Magnets 121b, 122b, 123b and 124b are provided in rim portion <NUM> around the aperture through the mask frame, and again may for example be embedded in this rim portion <NUM> during plastic moulding.

The magnets in the seal module and frame are positioned so that when the seal module is positioned against the mask frame in the correct orientation of the seal module and mask frame relative to one another, magnetic attraction will hold the seal module on the mask frame. Thus each pair of magnets 121a-121b, 122a-122b, 123a-123b, and 124a-124b, are provided so that the opposite poles of each pair face one another when the seal module is correctly oriented relative to the mask frame, and then magnetic attraction holds the seal module and mask frame together. It is preferred to provide magnets in both the seal module and mask frame, but alternatively magnets may be provided in the seal module only and a ferrous component or components provided in the mask frame (about aperture <NUM>), or vice versa, or some magnets may be provided in each of the seal module and mask frame and also ferrous components at other locations in each of the mask frame and seal module. At least one magnet or ferrous component is provided in the seal module and at least one ferrous component or magnet in the mask frame, or at least one magnet in each of the seal module and mask frame. In the arrangement shown four magnets are provided in each of the seal module and mask frame, approximately equi-distantly spaced about the apertures <NUM> and <NUM> as described.

In at least some arrangements at least two magnets are provided in the seal module <NUM> and at least two matching magnets in the mask frame <NUM>, and the two magnets in the seal module have opposite poles facing the mask frame and the same for the two magnets in the mask frame facing the seal module. For example in the arrangement shown in <FIG>, magnets 121a and 122a in the seal module <NUM> have north poles facing the mask frame, and magnets 123a and 124a have south poles facing the mask frame. Magnets 121b and 122b in the mask frame <NUM> have south poles facing the seal module and magnets 123b and 124b in the mask frame have north poles facing the seal module. Thus in the correct orientation of the seal module and mask frame relative to one another all magnets attract, to hold the seal module on the mask frame, but if the seal module is offered to the mask frame in at least one or more incorrect orientations, the magnets repel. The magnets may be arranged so that a seal module will couple to the mask frame only in one (correct) orientation of the seal module relative to the mask frame. Such an orientation may be achieved by an asymmetrical arrangement of magnets upon the seal module, coupling to an identical asymmetrical arrangement of opposite pole magnets upon the mask frame.

<FIG> shows another arrangement of an interface, in which magnet 130a on a right hand side (as the interface is worn) of seal module <NUM> has its north pole facing mask frame <NUM> and magnet 131a on a left side of the seal module has its south pole facing the mask frame. Magnet 130b on right side of the mask frame <NUM> has its south pole facing the seal module <NUM> and magnet 131b on left side of the mask frame has its north pole facing the seal module <NUM>. Two such magnets are provided in each of the seal module <NUM> and mask frame <NUM>. The seal module <NUM> will only magnetically couple to the mask frame <NUM> when the seal module is offered to the mask frame <NUM> in the correct orientation, such that magnet 130a is opposite magnet 130b and magnet 131a opposite magnet 131b. In other orientations of the seal module relative to the mask frame, either the magnets will not align so that there will be no magnetic attraction of the seal module to the mask frame, or in a reversed (upside down) orientation of the seal module, magnets 131a and 130a in the seal module will face magnets 130b and 131b in the mask frame and the magnets will magnetically repel, so that the seal module and mask frame cannot be coupled together, making it apparent to the user that the orientation of the seal module relative to the mask frame is incorrect. Unless otherwise indicated in this and later figures similar reference numerals as in <FIG> indicate similar components.

<FIG> is a schematic view of a seal module <NUM> which comprises nozzles 101a and interfacing part of a mask frame <NUM> of an interface of another arrangement, such as a frame rim <NUM>, and <FIG> are schematic views of magnet parts of the seal module and mask frame in correct and incorrect orientations relative to one another respectively. Three magnets 141a, 142a and 143a are provided in the seal module <NUM>, and three magnets 141b, 142b and 143b in opposite locations in the mask frame. Magnets 141a and 142a in the seal module have similar poles facing the mask frame eg north poles. Magnet 143a in the seal module has an opposite pole facing the mask frame (opposite to magnets 141a and 142a) eg south pole. Similarly in the mask frame magnets 141b and 142b have similar poles facing the seal module eg south poles, and magnet 143b has an opposite pole facing the seal module eg north pole. Thus the seal module and mask frame will attract only in one (correct) orientation of the seal module relative to the mask frame, as illustrated by <FIG> - correct orientation, and 7C - incorrect orientation.

Interfaces of the invention may rely solely on magnetic coupling of the seal module to the mask frame in use of the interface. Alternatively a magnetic coupling system may supplement, and be provided in addition, to mechanical coupling between the seal module and the mask frame, such as a friction fit, snap fit, or other interference fit, of formations on the seal module and mask frame to one another, either around the airway path through the mask frame into the seal module, or at other locations on the seal module and mask frame.

In some arrangements the interface may rely predominantly on mechanical coupling to hold the seal module on the mask frame, and a magnetic coupling system as described may be provided primarily to indicate correct and incorrect alignment of the seal module and mask frame when the user brings them together, so that coupling can only occur when the seal module and mask frame are offered to one another in correct alignment.

<FIG> are schematic views of an arrangement of a respiratory interface in which magnets associated with the seal module and mask frame are provided not directly around the airway path, but at left and right sides of the seal module and mask frame. In this arrangement one or more magnets, such as magnets 151a, 152a, and 153a, are provided on the left side <NUM> of the seal module, which couple to one or more magnets (or ferrous parts), such as and magnets 151b, 152b and 153b, on the side of a left part <NUM> of the frame of the mask. Similar magnets are provided on the right side of the seal and corresponding right side of the frame (not shown). The magnets attract when the seal module and mask frame are correctly aligned relative to one another. Around the airway path connection ie the connection of an air entry aperture centrally positioned into the seal module <NUM>, to an aperture through mask frame <NUM> from the conduit <NUM>, formations may be provided for a mechanical connection between the seal module and mask frame, to hold or assist in holding the seal module to the mask frame, or alternatively coupling of the seal module to the mask frame may rely primarily on the magnetic coupling system and simply a gas seal may be provided between the seal module air gases entry aperture and the mask frame to prevent air leakage. In the arrangement shown the seal is an under-nose indirect seal but may be any other seal type as previously described.

<FIG> are schematic cross-section views of interfacing parts of a seal module and mask frame of an interface of an embodiment of the invention. The objective of this embodiment is to produce an audible sound (eg 'click') on attachment and detachment of the seal module to/from one another. The interfacing parts of the seal module and mask frame are shown connected in <FIG>, near connected in <FIG>, and apart in <FIG>. In this embodiment magnet or magnets <NUM> associated with the seal module <NUM> for example about the periphery of an air entry aperture into the seal module, are mounted to the seal module such that they can move relative to the balance of the seal module, in the direction of the arrow in <FIG> between the magnet position shown in <FIG>, and the magnet position shown in <FIG>. For example the magnet(s) <NUM> may be embedded in a part 101e of the seal module designed to contact the mask frame <NUM>, which part of the seal module is formed of a stretchable material. For example the seal module may be moulded from a soft synthetic elastic material; the magnets are embedded in the soft material; and the soft material around the magnets is elastically stretchable so that the magnets can move relative to the balance of the seal module. Alternatively the magnets may be captured on for example a rim of the seal module by an elastically stretchable fabric cover.

<FIG> shows the seal module <NUM> connected or coupled to the mask frame. <FIG> shows the seal module and mask frame separated. The normal position of the seal magnet(s) is as shown in <FIG>. When the seal module is offered to the mask frame, as the seal module approaches the position shown in <FIG> relative to the mask frame, and continues to approach the mask frame, magnetic attraction will pull the magnet(s) of the seal module towards the magnet(s) <NUM> of the mask frame, stretching the magnet(s) <NUM> of the seal module away from the balance of the seal module as shown in <FIG>, until they contact the mask frame (then pulling the seal module fully towards the mask frame to the fully coupled position shown in <FIG>). As the seal module is brought towards the frame, at a break point at which the magnetic attraction of the seal and frame magnets to one another exceeds the elastic retractive force of the elastic part or stretchable fabric cover 101e of the seal module, the seal magnet(s) <NUM> will snap from the position of <FIG> to that of <FIG> and the impact of the seal module magnet(s) against the frame or frame magnets may produce an audible click. Similarly when the seal module is pulled from the mask frame ie the seal module is moved from the position shown in <FIG> to that shown in <FIG>, the magnet(s) <NUM> of the seal module will come away from the mask frame and snap back into position as shown in <FIG> which may again producing an audible click. The magnet(s) (or ferrous part(s)) on the frame are elastically movably mounted, or the magnets on both the seal module and frame. It may be advantageous that the magnet(s) movement as described produces an audible sound on coupling and uncoupling as an indicator to the user but in other embodiments the same structures as described may be employed but designed to couple and uncouple silently.

<FIG> are schematic cross-section views of interfacing parts of a seal module and mask frame of an interface of another arrangement, separated in <FIG> and connected in <FIG> is a schematic exploded view of magnet parts of the seal module and mask frame and a gel pad between as will be further described. This arrangement is similar to others previously described in which magnets or magnets and one or more ferrous components are provided on a seal module <NUM> and mask frame <NUM> about the airway path through the interface. In this arrangement a ring <NUM> of a compressible material is provided on the seal module <NUM> forward of the magnet(s) <NUM> about the seal module gases entry aperture <NUM> as shown. The compressible ring <NUM> may for example comprise a ring of captured gel ie gel captured in an annular membrane, or a compressible synthetic material or rubber ring for example. <FIG> shows the seal module <NUM> and mask frame <NUM> separated and <FIG> shows the seal module and mask frame coupled. When the seal module and mask frame are coupled the compressible ring <NUM> is between the magnet(s) <NUM> and <NUM> on the seal module and the mask frame, and may be compressed slightly. This may assist in ensuring an airtight seal between the seal module and mask frame for example.

In the arrangement shown a single magnet is provided on each of the seal module and mask frame, each in the form of a ring magnet as shown in <FIG>. Alternatively the magnets <NUM> and <NUM> on one or both of the seal module and mask frame may comprise two or more curved segments which collectively define a ring around the airway path through each of the seal module and mask frame, or alternatively again the magnets may be multiple smaller individual magnets as shown for other arrangements.

In each case and in any embodiment of the invention, a magnet or magnets may comprise a segment of solid (non-particulate) magnet material, or alternatively a particulate magnetic material ie particles of a magnetic material embedded by plastic moulding for example, for example in the seal module or mask frame. Particulate material may form a ring magnet as in <FIG> or multiple individual magnets as in other arrangements.

<FIG> show a further arrangement of seal module to mask frame magnetic coupling that allows a method of replacing or switching seal modules without removal of headgear from a user.

<FIG> is a rear view of a mask frame <NUM> i.e. shows the side of the mask frame which interfaces with the seal module, comparable to <FIG>; meanwhile <FIG> is a front view of a seal module <NUM> for covering the nose and mouth of a user, comparable to <FIG>. Magnets 121a and 122a are set into recesses on the seal module <NUM>. The magnets 121a and 122a are located on opposite sides of an aperture <NUM> through the seal module <NUM>. Surfaces of the magnets are flush with an outer surface of the seal module. This outer surface is a surface of radial flanges associated with a rim portion <NUM> of the seal module around the aperture <NUM>. In the illustrated form magnets 121a and 122a are arranged opposite each other at a lower portion of the rim portion <NUM>. The positions of the magnets 121a and 122a may be described as being at approximately four and eight o'clock positions respectively. The seal module also comprises a locator 121c in an upper portion. The locator is in an uppermost position upon the seal module <NUM>. The position of the locator 121c may be described as being at approximately a <NUM> o'clock position. The magnets 121a and 122a are equidistantly spaced from the locator 121c.

Corresponding magnets 121b and 122b are likewise set into recesses in the mask frame <NUM>. The magnets are located on opposite sides of an aperture through the mask frame. The magnets 121b and 122b on the mask frame are located so that they will be opposed to and engaged with respective magnets 121a and 122b on the seal module <NUM> when the seal module is joined to the mask frame. Surfaces of the magnets are flush with an inner surface of the mask frame. This inner surface is a surface of radial flanges associated with a rim portion <NUM> of the mask frame around the aperture. In the illustrated form magnets 121b and 122b are arranged opposite each other at a lower portion of the rim portion <NUM>. The positions of the magnets 121b and 122b may be described as being at approximately four and eight o'clock positions respectively. The mask frame also comprises a locator 121d in an upper portion. The locator is in an uppermost position upon the mask frame. The position of the locator 121d may be described as being at approximately a <NUM> o'clock position. The magnets 121b and 122b are equidistantly spaced from the locator 121d.

Although the illustrated arrangement shows the seal module and mask frame having two magnets and a single locator, it is to be appreciated that in other arrangements, the seal module and mask frame could each have <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or more magnets and/or <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or more locators.

Locating features 121c and 121d may have any suitable mating profiles that enable the locating features to inter-engage with each other. The profiles for the locating features may be shaped with keys that limit fitment between the locating features to particular orientations. The locator 121c on the seal module is a projection (male part) that projects forwardly of the seal module. The locator 121d on the mask frame is a recess (female part) that extends into the mask frame. The recess locator 121d is configured to receive the projection locator 121c. It is to be appreciated that in other arrangements, the locator on the seal module may be a recess and the locator on the mask frame may be a projection. The locator projection 121c has a wedge shape. That is, the locator projection 121c tapers as it extends away from the seal module. Such a wedge shape enables guidance of the locator projection into the locator recess and subsequent engagement of the magnets even when the seal module and mask frame are not perfectly aligned.

When the seal module is coupled to the mask frame, the receipt of the projection locator 121c in the recess locator 121d provides resistance to rotation of the seal module relative to the mask frame about the seal module aperture. However, the inter-engagement of the locators provides no limitation to linear movement of the seal module away from the mask frame. The engagement of the respective magnets 121a,b and 122a,b on the seal module and the mask frame, provides resistance to the linear movement of the seal module away from the mask frame but is weak at resisting rotation of the seal module relative to the mask frame about the seal module aperture. Accordingly, the locators and magnets provide a combination of mechanical and magnetic engagements to hold the seal module to the mask frame. The locators and magnets provide threshold resistance to disengagement of the seal module from the mask frame under rotation or linear forces. The threshold rotation force in a direction about the seal module aperture to cause disengagement is higher than the threshold linear force.

<FIG> shows a nasal seal module 101a that otherwise has the same configuration of magnets 121a, 122a and locating feature 121c about a rim portion <NUM> as the full nose/mouth seal module <NUM> of <FIG>. In this way it is compatible to be coupled with the rear of the same mask frame <NUM> shown in <FIG>.

<FIG> illustrate a method that can be implemented using the mask frame <NUM> and seal module components <NUM> and 101a and, particularly, a method of swapping seal module components without removal of the headgear.

A user U is shown in <FIG> wearing headgear and a nasal seal module 101a in place upon mask frame <NUM>. Headgear can be exemplified according to principles disclosed in the Applicant's <CIT>, e.g. paragraphs [<NUM>] - [<NUM>], [<NUM>] - [<NUM>], wherein with respect to patient interfaces that seal on the face of the user, the interface (e.g., mask) in cooperation with the user's face creates a sealed chamber. Pressurized breathing gases are delivered to the sealed chamber, which generates a force tending to move the mask away from the user's face. This force is generally equal to the (projected) seal area multiplied by the positive pressure and is often referred to as the "blow-off force. A function of the headgear is to restrain the mask in response to the blow-off force to keep the mask in equilibrium sealed against the face of the user. The blow-off force stresses the headgear in an attempt to elongate it, which places the headgear under tension.

In addition, the headgear applies a force to the user's head over an area with which the headgear is in contact. The force applied to the contact area can be referred to as the "skin pressure" of the headgear. As the air pressure within the chamber defined by the seal or the combination of the seal and the frame increases, the force applied by the headgear attempts to restrain the interface assembly from lifting from the face. As such, the force applied by the headgear generally will increase to oppose the increasing force resulting from the increasing pressure within the mask. The blow-off forces will vary for different types and sizes of interfaces at any given pressure. Nevertheless, at lower pressures, or no pressure in the case of cannulas, less force is required to oppose the blow-off forces.

Accordingly, headgear assemblies preferably can be designed to achieve a "balanced fit. " In some configurations, the headgear assemblies generally comprise a stretch component (also referred to as elastic), a non-stretch component (also referred to as inelastic or non-elastic), a mechanism that restricts extension of the headgear, and a coupling that can join the headgear assembly to the mounting points, for example but without limitation. In at least some configurations, the balanced fit can be achieved by creating a substantially non-stretch path to resolve the stresses in the headgear when in use or in response to normal operational forces (e.g., blow-off and/or hose pulls forces, plus a reserve, if desirable). At higher forces than seen in use, the headgear can exhibit stretch-like behaviour for donning. In some configurations, the headgear assembly may not include a stretch component. For example, the headgear could be manually extended and retracted.

The stretch components, when present, can have any suitable configuration. The stretch components can be any component that has a tensile modulus of less than about <NUM> MPa. The tensile modulus is the mathematical description of the tendency to be deformed elastically (i.e., non-permanently) along an axis when forces are applied along that axis; tensile modulus is the ratio of stress to corresponding strain when a material behaves elastically. In some configurations, the stretch component can be a coated, spun yarn material and the stretch component can include materials such as, but not limited to, rubber and spandex or elastane (e.g., LYCRA). In some configurations, the stretch component can be a strap or a combination of straps. In some configurations, the stretch component can be formed of a stretchable or elastic material. In some configurations, the stretch component enables the headgear to be expanded or lengthened and the stretch component also provides a retraction force that serves to contract or shorten the headgear. The contraction, or shortening, can occur as a result of the elastic properties of the stretch component. The contraction, or shortening, allows the headgear to more closely match the user's head circumference (plus the size of the mask). Generally, the headgear length is defined by a relaxed length and the headgear seeks to return to that length and it is this returning toward the relaxed length after elongation that is meant by contraction unless otherwise apparent.

The non-stretch components can serve as a stretch limiter. The non-stretch components can have any suitable configuration. In some configurations, the non-stretch components have a higher modulus of elasticity compared to the stretch components. The stretch components can be any component that has a tensile modulus of more than about <NUM> MPa. In some configurations, the non-stretch components restrict elongation of the headgear due to forces that are lower than a specified yield force. In some configurations, the yield point of the non-stretch material is higher than any anticipated loading to be applied to the headgear. In some configurations, the non-stretch components resist elongation of the headgear once the headgear has been fitted to the head. In some configurations, the non- stretch components resist elongation of the headgear once the headgear has been fitted to the head and the CPAP pressure has been applied to the mask. Thus, in some configurations, the non-stretch components (in some cases, in combination with the mechanisms discussed below) can thwart or resist elongation of the stretch components at least when CPAP pressure is applied. In the case of a cannula, the non-stretch components can resist the movement of the cannula under the influence of external forces, such as hose pull.

The mechanism can be any suitable mechanism that can limit expansion or elongation of the headgear when a force lower than a specified yield force is applied to the headgear. In some configurations, the mechanism operates without an effort by the user (e.g., the mechanism is automatic). That is, in at least some configurations, the mechanism can automatically move or switch to a mode in which extension or expansion is limited below the specified yield force. However, effort may be required for the user to don the mask, such as effort above the yield force to extend the headgear. In some configurations, the mechanism can apply a motion resistance force that can limit the extension or expansion of the headgear when a force lower than the specified yield force is applied to the headgear. In some such configurations, the motion resistance force can be a friction force. The specified yield force, that is, the force at which the headgear mechanism's motion resistance forces are overcome and elongation of the headgear becomes possible, may be determined by (<NUM>) the maximum blow-off force that is possible for the specific mask in use when a range of about <NUM>-<NUM> cmH20 pressure is anticipated and (<NUM>) a reserve to allow for any pulling of the CPAP hose and differences in user fit preferences. The reserve, generally defined as the difference between the lengthening or extension force and the maximum balanced fit force, can provide a buffer above the balance fit force, in which additional forces can be applied to the headgear without substantial elongation of the headgear occurring. The reserve force component can compensate for any additional force, such as hose pull, that may act to pull the headgear from the user's head. In some configurations, the motion resistance force can be applied to restrict extension of the headgear while releasing to allow retraction or contraction of the headgear. In some configurations, the mechanism can use one-way friction to lock or otherwise secure the headgear length. For example, the length can be secured using a factional force that can only be overcome by a force that exceeds the blow-off force with minimal extension. Such mechanisms can be referred to herein as a directional locking arrangement or directional lock. The term "lock" as used herein is intended to cover mechanisms that secure the headgear length in response to certain forces, such as blow-off forces and/or hose pull forces. A "lock" does not necessarily secure the headgear length in response to all forces. Preferably, in some configurations, the retention force of the lock ("lock force") can be overcome, such as by manually-applied forces during the application portion of the fitment process.

To remove the interface while wearing the headgear described below, the seal can be pulled forward with a force greater than the mechanism's maximum holding force. This causes the headgear to lengthen and which enables the seal to be pulled away from the face and over the user's head. Once removed, the lack of forces on the headgear will cause the headgear to automatically retract to its relaxed size.

In some configurations, the headgear applies a three phase force extension fit profile. In the application phase, the headgear is stretched to go over the head of a user. A load curve features a steep rise in load for the initial extension of the headgear that then transitions to a generally constant, flat extension curve as the headgear is further stretched to accommodate larger head circumferences. In the adjustment phase, the headgear retracts and returns from a stretched condition until a desired fit is achieved. The load curve shows an initial decrease in load as the headgear retracts to fit onto the user's head and also illustrates a low load force as the headgear further retracts to fit the user's head circumference. In the third phase, the balanced fit phase, the headgear adjusts to hold its position on the user's head as CPAP pressure is applied. The load curve illustrates that a rise in load force of the headgear balances with the blow-off force due to the CPAP pressure and also resists additional forces, such as hose pull. In the case of a cannula arrangement, a balanced fit can be achieved at the end of phase two, and phase three typically will only be initiated if and when an external force, such as hose pull, is experienced.

As discussed above, the load curve will have a steep rise because the headgear has initial resistance to stretch as it is stretched to accommodate the user's head. The initial resistance can relate to overcoming the resistance that will resist elongation. Once the load has reached a yield force of the mechanism of the headgear, the load curve transitions to a substantially flat, generally constant extension curve as the headgear stretches further with little increase in load force for greater amounts of headgear extension.

In the second phase, the headgear has been sufficiently stretched or elongated to fit over the user's head and the headgear has been released into position. Once a desired positioning has been achieved, the headgear returns from the stretched condition (e.g., over-elongated position) and the load force sharply declines. After this reduction in force due to retraction of the headgear to fit the user's head, the load curve remains low <NUM> as the headgear remains fitted to the user's head. The headgear that typifies many features, aspects and advantages of the present invention features a first high load required to cause elongation and a second lower load at which the headgear contracts. In other words, the headgear contracts at a lower load than required to cause elongation and a hysteresis is the provided effect. In some configurations, the headgear has a delay in length change while the force changes dramatically when changing from an elongation mode to a contraction mode. In some configurations, the change in length of the interface circumference (including the headgear assembly) lags behind changes in load (i.e., force) when the interface length changes from elongation to contraction. Moreover, in some configurations, during elongation, as the force increases, the length increases more than the decrease in length during the decrease in force.

A balanced fit is achieved in the balanced fit phase, in which the force of the headgear balances the blow-off force of the CPAP pressure. As mentioned above, the headgear adjusts to hold its length as CPAP pressure is applied. The load curve will show the rise in the load force that balances the blow-off force. The balanced fit produces a higher load than the retraction force of the headgear. The balanced fit component is the increasing force in the strap of the headgear that provides an equal and opposite force to the blow-off force. However, this force is also lower than the lengthening or extension curve. In some configurations, the slope of the balanced fit section is related to, influenced by, or can be substantially the same as the rise and/or the decline in the load force during retraction of the headgear. In some configurations, the slope of the balanced fit section is steeper than the slope in the decline in the load force. In some configurations, the slope of the balanced fit section is greater than the slope in the initial rise during lengthening of the headgear.

<FIG> shows the process of removing nasal seal module 101a, ie, by gripping a lower part of mask frame <NUM> and pulling it away from the face of user U, while it remains strapped to the head, to naturally form a gap G, against the bias of an elastic portion of a headgear strap and by decoupling of the magnetic connection of the type described herein.

Still with reference to <FIG> the seal module 101a is then gripped at its accessible, bottommost, end and pulled toward the face of user U, thereby breaking the engagement between magnets 121a/121b and 122a/122b respectively. Nasal seal module 101a can then be decoupled from the posterior of the frame and removed through gap G between the user's face and mask frame <NUM>. The force applied by the user U to achieve disengagement has to overcome the threshold forces that resist such disengagement. Disengagement can be achieved by 'peeling' the seal module away from the mask frame. By this process, the locator projection acts as a pivot whereby the seal module is pivoted upwardly about the locator projection to break the engagement between the magnets. Pivoting about the locator projection is facilitated by the wedge shape of the projection and that the height of the projection is less than the height if the locator recess.

With gap G still open a replacement seal module <NUM> can be inserted into the space in front of the face and connected to the rear side of the frame. The replacement seal module <NUM> may be the same type of seal module or a different type. For example, the replacement module may be a full face seal module where the original seal module is a nasal seal module. Mask frame <NUM> is then released to close gap G so that the replacement seal is brought into engagement with the user's face. Magnetic connections 121a/121b and 122a/122b respectively join frame <NUM> to the 'replacement' seal module <NUM>, aided by locating features 121c/121d to correctly orient the components and the magnets themselves which will tend to pull the assembly into place by magnetic forces. In particular, wedge shaped locator 121c approaches locator recess 121d to guide mask frame <NUM> into position against seal module <NUM> before or at the same time as the corresponding magnets begin to engage by magnetic attraction.

In the illustrated form magnetic connections 121a to 121b etc. allows for the seal module <NUM>/101a to be quickly and easily swapped out without the need to completely remove the full headgear or operate any complicated clipping means. Magnets being located at the lower part of the aperture with a locating feature at the top enables a seal module to be 'peeled' away by a relatively small force. Furthermore, magnets pull the parts into correct alignment, such that initial alignment does not need to be perfect between the rear/posterior of the mask frame and front/anterior of the seal module. The magnetic attachment system as described allows seal modules to be interchanged in the dark; e.g. where a user may want to change between a full face and nasal mask during the night for comfort. It is intended that the conduit aperture is located in such a place that when the mask frame <NUM> is connected to either the nasal or full face module, the apex/bridge of the seal module will be in the same place relative to a user's facial geometry.

<FIG> and <FIG> show, and illustrate the operation of, a seal comprising at least one magnet or ferrous part associated with the seal to hold a first part of the seal in position relative to another part of the seal or part of the mask frame of the respiratory interface, to magnetically hold an adjustment position of a part of the seal. In the arrangement shown multiple magnets and/or ferrous parts are provided in a nasal bridge part <NUM> of the seal, to hold in the nasal bridge part of the seal in a selected adjustment position. The nasal bridge part <NUM> of the seal is compliant as indicated by arrow C in <FIG>, <FIG>, enabling the nasal bridge part of the soft flexible seal to move forward of its normal position shown in <FIG>, to for example either of the two positions shown in <FIG>, to accommodate users with different depths of nasal bridge, so that the seal does not place excessive pressure on the nasal bridge area of the nose of the wearer. Such a compliant nasal bridge is described in our international patent publication <CIT>.

Magnets 201a and 202a are embedded in a forward part of the soft moulded material of the nasal bridge portion of the seal which moves to provide nasal bridge compliance of the seal, and magnets 201b and 202b are embedded in an adjacent (non-moving) part of the seal for example a shell part of the seal module formed of a relatively harder material (as escribed in relation to <FIG> for example). The magnets particularly in the thin wall section flexing or folding nasal bridge part of the seal may comprise zones of embedded particulate material moulded in the silicone or other soft material from which the seal is formed, which extend transversely across the nasal bridge part of the seal from left to right for example (magnetic lines). The magnets are arranged with their poles oriented such that magnets will attract in defined discrete positions of adjustment. Two such positions are shown in <FIG>. If the nasal bridge part of the seal is moved from the 'normal' position of <FIG>, to the position of <FIG>, to accommodate a medium depth nasal bridge user, in the position of <FIG> magnets 201a embedded in the nasal bridge portion of the seal and 201b embedded in the non-moving part of the seal, will align to hold the seal in this position of adjustment. However if the user pushes the nasal bridge part of the seal further forward, to the position shown in <FIG>, to accommodate a higher depth nasal bridge, a different pair of magnets namely magnets 202a embedded in the nasal bridge portion of the seal and 202b embedded in the non-moving part of the seal, will align also as shown, or instead, to hold this adjustment position.

The arrangement shown has two positions of magnetic hold of adjustment but in other arrangements magnets may be provided in the seal and/or frame to provide three or more, on only one, magnetic adjustment hold position.

In the arrangement shown the compliant nasal bridge is provided in the seal module of an interface comprising a mask frame and separate seal module but such a magnetic adjustment system of the nasal bridge may be provided in the compliant nasal bridge of a seal which is non-detachable from the mask frame for example a seal which is permanently overmoulded to the mask frame.

<FIG> is a schematic side view of an arrangement of a respiratory interface comprising a nasal seal part and an oral seal part which are detachably magnetically coupled. The interface comprises an oral seal first part <NUM> to deliver gases through the mouth, supplied in the arrangement shown to the interface via conduit <NUM>, and a nasal seal second part <NUM> to deliver gases to the nose also. The nasal seal part <NUM> may be an indirect or direct nasal seal as described. A magnetic coupling system magnetically couples the oral seal part <NUM> and nasal seal part <NUM> together to form, when coupled, a combined oro-nasal seal.

In the arrangement shown the oral seal part <NUM> comprises magnets <NUM> around an upper peripheral part and the nasal seal part comprises magnets <NUM> around a lower peripheral part, both on left and right sides and across the front of the seal, or alternatively a single strip magnet in each seal part instead of discrete magnets as shown, or embedded particulate magnetic material, embedded in the seal during moulding for example, which magnetically couple the seal parts together or embedded particulate magnetic material, embedded in a soft synthetic insert <NUM> during plastic moulding for example.

The seal parts may be attached to one another or coupled, and detached from one another, so that the interface may be used with both seal pats together or with the oral seal part only. In an alternative arrangement the conduit may connect to a nasal seal part so that an oral seal part may be magnetically coupled to or detached from the nasal seal part enabling the nasal seal part to be used alone.

In the arrangement shown the two seal parts <NUM> and <NUM> magnetically couple together but in an alternative arrangement one or both of the seal parts may also or alternatively magnetically couple to a common mask frame, again so that one or other of the seal parts may be detached to enable the interface to be used as an oral-only, or nasal-only, interface if the other seal part is detached.

In some arrangements the magnetic coupling system comprises at least one magnet associated with one of the first and second seal parts or mask frame and at least one ferrous part associated with one of the first and second seal parts or mask frame. In other arrangements the magnetic coupling system comprises magnets associated with each of the first and second seal parts or one of the first and second seal parts and the mask frame. In some arrangements at least one magnet associated with one of the first or second seal parts or the mask frame and at least one magnet associated with another of the first or second seal parts or the mask frame are provided to the seal parts or mask frame such that they attract when the seal parts are coupled each other or to the mask frame in a predetermined correct orientation and repel in any orientation other than said predetermined correct orientation.

<FIG> is a perspective view from above of an arrangement of an oral insert configured to be retained in a user's mouth when a mask is worn, to assist in retaining the mask in position on the face of the user. Oral insert <NUM> is configured to be retained at least in part on the teeth of the user. In the arrangement shown the oral insert <NUM> has an approximate U-shape as shown, and comprises an upwardly facing open channel <NUM>, so that it is configured to be retained on the left right and front upper teeth of the user when worn. When worn the oral insert <NUM> remains attached to the teeth securely, but is shaped and sized so as to be as minimally invasive and as maximally comfortable as possible. The insert may be formed of a material which is soft but has some structural rigidity, such as a silicone material for example. The dimensions across the upwardly facing channel <NUM> are such that the insert will remain wedged on the teeth.

The insert comprises magnets <NUM> spaced around its forward periphery as shown, or alternatively a single magnetic strip may extend around the front periphery of the insert. The magnets or magnetic strip may comprise a solid magnet or magnets or embedded particulate magnetic material, embedded in a soft synthetic insert <NUM> during plastic moulding for example.

A corresponding magnet or magnets are provided on a mask (not shown in <FIG>) particularly the seal or cushion at the left and right sides of in the upper lip region or across the upper lip region, so that when the oral insert <NUM> is in place on the user's teeth, and the mask is placed in the correct location on the face, the mask will magnetically couple to the oral insert <NUM> to at least assist in retaining the mask in position on the face of the user. This may be in addition to headgear coupled to the mask, so that the magnetic system stabilises the mask on the face for example, or in some arrangements the interface does not also comprise headgear and the magnetic coupling system through the oral insert <NUM> solely retains the mask in position when worn by the user.

In arrangements the magnetic coupling system comprises at least one magnet associated with one of the mask or oral insert and at least one ferrous part associated with the other of the mask or oral insert. In arrangements the magnetic coupling system comprises magnets associated with both of the mask or oral insert.

<FIG> is a longitudinal cross-section part view of a conduit connected to the end of an elbow of a mask by a magnetic coupling system according to an arrangement, and <FIG> is a longitudinal cross-section part view similar to <FIG> but in which only a part of the conduit is shown in cross-section. In these figures flexible conduit <NUM>, for example from a CPAP machine to a respiratory interface, comprises at one end a rigid or semi-rigid annular part or fitting <NUM>, which is received over a rigid or semi-rigid annular fitting <NUM> which is part of or attached to the interface. For example part <NUM> may be the lower end of an elbow connecting to the mask, or may be a fitting on the bottom end of a short lead in tube forming part of the mask. Annular magnets <NUM> are embedded in the part <NUM>, for example during plastic moulding of the part <NUM>, and corresponding annular magnets <NUM> are embedded in the part <NUM> during moulding of this part for example. There may be one or more magnets in each part, which may be discrete ring or segmented ring or magnets or embedded particulate magnetic material magnets. The magnets <NUM> and <NUM> are positioned, and part <NUM> has a slight internal taper and part <NUM> a slight external taper, so that when the parts <NUM> and <NUM> are brought together the magnets will align and magnetically couple part <NUM> on the end of conduit <NUM> to the part <NUM> on the bottom end of the elbow or mask lead in tube. The magnetic coupling may or may not form a frictionless or near frictionless swivel ie the part <NUM> can rotate about the longitudinal axis of the coupling without becoming detached from the part <NUM>.

In the arrangement shown the magnet coupling system is between conduit <NUM> and part <NUM> which is described above as at the bottom end of an elbow or lead in tube to a mask but alternatively part <NUM> may be comprising a fitting such as a fitting of a CPAP machine for coupling a conduit to a CPAP machine or in any other context, or may be provided at the end of another length of conduit, for coupling together two conduit lengths, for example.

In arrangements the magnetic coupling system comprises at least one magnet associated with one of the conduit to the mask and the mask or a lead in tube to the mask and at least one ferrous part associated with another of the conduit to the mask and the mask or a lead in tube to the mask. In arrangements the magnetic coupling system comprises magnets associated with both of the conduit to the mask and the mask or a lead in tube to the mask.

In arrangements at least one magnet associated with one of the conduit to the mask and the mask or a lead in tube to the mask and at least one magnet associated with another of the conduit to the mask and the mask or a lead in tube to the mask are provided to the conduit and the mask or a lead in tube to the mask such that they attract when the conduit and the mask or a lead in tube to the mask are coupled each other or to the mask frame in a predetermined correct orientation and repel in any orientation other than said predetermined correct orientation.

<FIG> and <FIG> schematically show components of an arrangement of a respiratory interface having a magnetic coupling system <NUM> for connecting a conduit to a mask or to a lead in tube to the mask to deliver respiratory gases to the user. The illustrated components of the respiratory interface are a seal module <NUM> and elbow <NUM>. The seal module <NUM> and elbow <NUM> may have the features and operation of earlier described arrangements, except the differences described below.

<FIG> are schematic views of magnet parts of the seal module <NUM> and elbow <NUM> in incorrect and correct orientations relative to one another respectively. When the seal module <NUM> and the elbow <NUM> are correctly oriented (<FIG>), the outlet aperture <NUM> of the elbow and the inlet aperture <NUM> of the seal module are aligned. As shown in <FIG> this involves alignment of the apertures' <NUM>, <NUM> central axis. <FIG> shows the misalignment of the apertures' <NUM>, <NUM> central axis when the seal module and the elbow are incorrectly oriented.

The magnetic coupling system <NUM> comprises two annular magnets <NUM>, <NUM> provided in the seal module <NUM> with a space between them. One magnet is a coupling magnet <NUM> and one magnet is a repulsing magnet <NUM>. Both magnets <NUM>, <NUM> surround and are spaced from the inlet aperture <NUM> of the seal module <NUM>. The magnetic coupling system <NUM> also comprises an annular magnet <NUM> in the elbow <NUM> in a location such that it will align with the coupling magnet <NUM> on the seal module <NUM> when the elbow is correctly orientated with respect to the seal module. In the arrangement shown, the elbow <NUM> has a flexible flange <NUM> and the annular magnet <NUM> is provided at or near a periphery of the flexible flange <NUM>. The flange <NUM> extends outwardly from the elbow <NUM> and extends around the perimeter of the elbow. Although it is to be appreciated that in other arrangements the flange only extends around a portion of the elbow or comprises a plurality of flange segments that are distributed about the perimeter of the elbow. The flange <NUM> is located close to the outlet aperture <NUM> of the elbow. The flange <NUM> is configured to be positioned over a portion of the seal module's external surface surrounding the inlet aperture <NUM>. The flexibility of the flange enables the flange to conform to the shape of the seal module's external surface and form a seal.

Although in the illustrated arrangements of <FIG> the magnets <NUM>, <NUM>, <NUM> are shown as unitary annular magnets, in other arrangements one or more of the magnets comprises two or more magnets in an annular arrangement. Any or all of the annular magnets <NUM>, <NUM>, <NUM> can be made from a soft magnetic material, such that it is conformable to the geometry of the seal module <NUM>. A soft magnet may provide an airtight connection between the seal module <NUM> and the elbow <NUM>.

The coupling magnet <NUM> in the seal module <NUM> has an opposite pole (for example north) to the magnet <NUM> of the elbow <NUM> (for example south). The repulsing magnet <NUM> will have the same pole as the magnet <NUM> of the elbow <NUM> (for example south). Thus, the seal module <NUM> and elbow <NUM> will attract only in one (correct) orientation and/or position of the seal module <NUM> relative to the elbow, as illustrated by <FIG> - incorrect orientation, and 38b - correct orientation. Further, when in the incorrect orientation, the magnets <NUM>, <NUM>, <NUM> will encourage the elbow <NUM> to move towards the correct orientation and/or position. This will occur if the elbow <NUM> is correctly aligned and is then moved or knocked. That is, the elbow <NUM> is self-centring or self-locating. If a user places the elbow <NUM> near the seal module <NUM>, the magnets <NUM>, <NUM>, <NUM> will encourage the elbow <NUM> towards the correct orientation.

As described above in relation to other arrangements, interfaces may rely solely on magnetic attraction of the seal module <NUM> to the elbow <NUM>. In alternative arrangements a magnetic coupling system supplements, and is provided in addition to, other coupling systems as described above. In some arrangements, the interface relies predominantly on mechanical coupling to hold the seal module <NUM> relative to the elbow <NUM>, and a magnetic coupling system as described is provided primarily to self-centre the seal module <NUM>.

<FIG> schematically shows an arrangement of headgear for a respiratory interface, comprising headgear parts and a magnetic coupling system arranged to magnetically couple headgear parts to one another.

In the arrangement shown the headgear comprises a rear strap <NUM> and top or crown strap <NUM>, which couple magnetically to the ends of left and right side straps or side arms <NUM> from mask <NUM>, which extend in use across the left and right sides of the face of the wearer. In the arrangement shown landing parts 503a are provided at the ends of side straps or arms <NUM>. The left and right ends of rear strap <NUM> comprise a magnet or magnets and the left and right ends of top strap <NUM> each comprise a magnet or magnets, as do the landing parts 503a of left and right side straps or arms <NUM>, so that the ends of the rear strap <NUM> and top strap <NUM> can be coupled to the ends 503a of the side straps or arms <NUM>, to assemble the headgear for use as shown.

In arrangements the first and second, and optionally third or third and fourth headgear parts, comprise at least one magnet at or towards one end thereof and at least one ferrous part at or towards another end thereof.

The magnets may be discrete solid magnets or comprise embedded particulate magnetic material.

Headgear in any form such as bifurcated or four point headgear having both top and bottom side straps to the interface on left and right sides, may be formed in whole or part as described so that for example headgear may have a top strap which is attached to the rest of the headgear magnetically and can be removed if desired by the user.

In arrangements at least two magnets associated with one of one of the first and second, and optionally third or third and fourth headgear parts and another with another of the first and second, and optionally third or third and fourth headgear parts, are provided to the headgear parts such that they attract when the headgear parts are coupled in a predetermined correct orientation and repel in any orientation other than said predetermined correct orientation.

<FIG> show arrangements of headgear for a respiratory interface comprising a magnetic coupling system to magnetically couple headgear straps or parts together.

In <FIG> straps <NUM> and <NUM> adjustably connect together. Strap <NUM> carries protrusion <NUM> having a magnet or magnets associated therewith such as embedded in the strap at and within the protrusion during moulding of a plastic strap for example, or embedded in a separate plastic part in turn bonded to a strap of soft material strap such as Breath-O-Prene® or similar material strap for example. Strap <NUM> carries a series of adjacent apertures <NUM> each having a small annular magnet embedded in the strap around the aperture. The magnet in protrusion <NUM> and associated with apertures <NUM> are oriented such that when the protrusion <NUM> is entered into one of the apertures <NUM> it will magnetically attract to and couple to the strap.

<FIG> shows a similar arrangement in which protrusion <NUM> is provided on the underside of the end of strap <NUM>, and recesses <NUM> which are optionally semi-connected to form a channel with corrugated sides as shown, are provided in the end of strap <NUM>. Whereas in the arrangement of <FIG> the apertures <NUM> may penetrate completely through the strap end, in the arrangement of <FIG> the apertures <NUM> are blind and magnet or magnetic particulate material alternatively are embedded during plastic moulding of the strap for example in the base of the apertures <NUM>. This arrangement also comprises a loop <NUM> through which the strap end <NUM> passes before connecting to strap <NUM>.

Alternatively the magnetic protrusion <NUM> or <NUM> may be provided at or towards the end of a side strap which couples to a mask or forehead rest part of a mask, and apertures <NUM> or <NUM> provided on the left and right sides of the mask body or forehead rest, to couple the side straps to the mask body or forehead rest in the same way.

In arrangements the first headgear part comprises at least one magnet or at least one ferrous part associated with said protrusion and the second headgear part or mask comprises at least one magnet or at least one ferrous part associated with said one or more recesses. In arrangements the headgear comprises the first headgear part comprises at least one magnet associated with said protrusion and the second headgear part or mask comprises at least one magnet associated with said one or more recesses.

<FIG> shows an arrangement of headgear for a respiratory interface comprising a magnetic coupling system, and a decoupling tool.

In the arrangement shown magnet <NUM> is provided at or towards the end <NUM> of strap <NUM>. For example magnet <NUM> may be a solid or particulate material magnet embedded within a plastic moulded strap end <NUM> of strap <NUM> which may otherwise be of a softer strap material for example. Magnet <NUM> is similarly embedded in another strap end or headgear part, or a mask body including forehead rest, for example. Decoupling tool <NUM> is provided, comprising solid or particulate material magnet <NUM> embedded therein. When the decoupling tool <NUM> is inserted between the strap ends or the strap and mask part, to decouple same, specifically in the example shown between magnet <NUM> and magnet <NUM>, in the correct orientation, doing so will tend to force the strap ends or the strap and mask part, specifically in the example shown the magnets <NUM> and <NUM>, apart decoupling the same. For example the decoupling tool <NUM> may be slid along the inside face of strap <NUM> and strap end <NUM> towards magnet <NUM> and <NUM> in use.

Preferably the decoupling tool <NUM> comprises a visual indicator on an exterior thereof indicating a correct orientation for inserting the decoupling tool <NUM> between the straps and mask or two straps. For example the decoupling tool may have a colour or word or shape embedded in or marked on the surface of one or both sides, such as 'inside' and 'outside' or similar, or the decoupling tool may be formed in a shape which indicates to a user the correct orientation relative to the parts being decoupled in which the tool should be used. In a further arrangement the decoupling tool <NUM> may have a tapered/sharp leading edge in order to initially prise apart coupled magnets, with decoupling of magnets <NUM> and <NUM> further assisted by an embedded magnet <NUM> as the tool is manually pushed therebetween.

With reference to <FIG>, another arrangement of headgear for a respiratory interface is shown. The interface may have the features and operation of earlier described arrangements, except the differences described below. The headgear comprises a first headgear part having an inflatable portion, a second headgear part, a magnetic coupling system arranged to magnetically hold the first and second headgear parts together. The first headgear part and second headgear part are left and right side arms <NUM> respectively. The arms <NUM> are in the form of straps. The first left and right side arms <NUM> overlap when engaged.

<FIG> shows a cross-section of an arm <NUM> that is free of magnetic material. <FIG> having a magnet <NUM>. The left and right side arms <NUM> both comprise magnet free portions and portions with one or more magnets <NUM>. As described in relation to other arrangements, each magnet <NUM> may be a solid or particulate material magnet embedded within a plastic moulded strap end of the strap which may otherwise be of a softer strap material for example.

The headgear has a decoupling mechanism that moves the arms and decouples the magnets. The decoupling mechanism comprises a pump associated with the inflatable portion that is arranged such that activation of the pump causes the inflatable portion to inflate, causing the first and second parts to move relative to each other. The pump is a squeeze pump that causes the inflatable portion to inflate by being squeezed by a user. The pump is preferably formed as part of the mask <NUM>, but may be provided as part of the arms <NUM> or other part of the interface or headgear.

In the arrangement shown, the left and right side arms <NUM> both have an inflatable portion and activation of the pump causes the inflatable portion of both arms to inflate. The arms <NUM> move away from each other by one or both of the arms moving from a curved configuration (<FIG>) to a relatively straight configuration (<FIG>). In the arrangement shown, a substantial portion or the entire length of each or both of the arms <NUM> is inflatable. As shown in <FIG> the inflatable portion of the arm(s) is provided by a hollow core <NUM> formed in the arms.

With reference to <FIG>, another arrangement of headgear for a respiratory interface is shown. The interface may have the features and operation of earlier described arrangements, except the differences described below. In <FIG>, the arms <NUM> adjustably connect together. Both straps have magnets <NUM> associated therewith such as embedded in the arms <NUM> during moulding of a plastic strap for example, or embedded in a separate plastic part in turn bonded to a strap of soft material strap such as Breath-O-Prene® or similar material strap for example. The magnets <NUM> in each arm <NUM> are oriented such that when the straps overlap, they will magnetically attract to each other. In alternative arrangements, one of the arms <NUM> has magnets and the other strap has at least one ferrous portion. <FIG> is a schematic view of the headgear of <FIG> in a relatively large sized configuration, and <FIG> is a schematic view of the headgear of <FIG> in a relatively small sized, in-use configuration.

With reference to <FIG>, another arrangement of headgear for a respiratory interface is shown. This arrangement is similar to the arrangement shown and described in relation to <FIG>, except that the size of the strap is personalised to the user. In particular, the user's head will be measured and the straps will be manufactured to have the magnets <NUM> positioned in the correct location to fit the user.

In some configurations, portions of the headgear assembly can be substantially non-stretchable. For example, the back strap, top strap and upright straps can be non-stretchable such that the portion that encircles the occipital region of the users head is made from non-stretch material. In some configurations, non-stretchable portions can comprise of a substantially non-stretch insert. The non-stretch insert can be attached to the headgear assembly, for example, by over-lock stitching, by ultrasonic welding, by use of glue or other adhesives, or by any other method. In some configurations, one or more of the side straps can also be formed of a substantially inelastic or non-stretchable material. The side straps can be formed of a semi-rigid, self-supporting material such that the semi-rigid headgear assembly can assume a substantially three-dimensional shape and generally does not tangle. The non-stretchable characteristic can be achieved by embedding at least one relatively inelastic panel in the portion of the headgear assembly that is desirably non-stretchable. The panel can be formed of a relatively low-stretch material, such as a polyester Breath-O-Prene® material, for example but without limitation. In some configurations, the headgear can be semi-rigid to secure the mask assembly to the user's head. The semi-rigid headgear can be formed as a composite structure comprising a semi-rigid strap that is joined to a soft edging. For example, the soft edging can be bonded to the semi-rigid strap by plastic overmolding or by use of an adhesive. The soft edging can be butt-joined to the semi-rigid strap, without the soft edging overlapping the semi-rigid strap, to maintain the continuous profile of the semi-rigid headgear. The semi-rigid strap can define and maintain the semi-rigid headgear shape as tension is applied from the straps to pull the mask assembly towards the user's head. In other words, the semi-rigid strap can be sufficiently rigid along its planar axis to prevent its upper and lower side straps from overly deforming under tension. The semi-rigid strap can be made from a variety of rigid or semi-rigid materials, including plastic or metal. In some configurations, the semi-rigid strap is made from PVC. Especially in connection with a semi-rigid headgear assembly, it has been found that the shape holding, or self-supporting nature, can result in an overall assembly that is intuitive to fit. In particular, where the connection and/or headgear members are self-supporting such that they maintain a three-dimensional form as discussed earlier, the headgear can be fitted in the correct orientation with very little if any instruction. In a self-supporting arrangement, the tendency of the straps to not tangle also reduces the time taken to fit the overall assembly. As used herein, the term "semi-rigid" is used to denote that the headgear assembly is sufficiently stiff such that the headgear assembly can assume a three-dimensional shape with dimensions approximating the head of the user for which the headgear is designed to fit while also being sufficiently flexible to generally conform to the anatomy of the user. For example, some of the other components (e.g., side straps) of the headgear assembly may also be partially or wholly "semi-rigid" such that the components are capable of holding a three-dimensional form that is substantially self-supporting. A "semi-rigid" headgear assembly is not intended to mean that each and every component of the headgear assembly is necessarily semi-rigid. For example, the substantially three-dimensional form that the self-supporting headgear assembly may assume may relate primarily to the rear and top portions of the headgear assembly. In addition, the semi-rigid headgear assembly may include semi-rigid regions that extend forward of the ears and above the ears when placed on the head of the patient.

The upper and lower side straps can be formed of a semi-rigid material, as well. Where used herein, the semi-rigid materials can include molded plastic or sheet materials that include, but are not limited to, homogeneous plastic materials and bonded non-woven fiber materials. In some configurations, the semi-rigid properties of the materials can be achieved with high-density foam material. The dense foam material can provide some structural rigidity to the upper and lower side straps, or other portions of the headgear assembly. In some configurations, the semi-rigid material can include textiles that are semi-rigid, such as denim or hemp. In some configurations, the material can comprise a laminate structure of both conformable and semi-rigid portions, for example but without limitation. The semi-rigid straps may be of a self-supporting, resilient, substantially inelastic material, such as Santoprene, polyolefin, polypropylene, polyethylene, foamed polyolefin, nylon or non-woven polymer material for example but without limitation. In some configurations, the semi-rigid strap is formed from the polyethylene or polypropylene families. The semi-rigid strap can be formed of a material such that the semi-rigid headgear is substantially shape-sustaining under its own weight regardless of its orientation. A soft edging can cover or attach to at least a portion of the periphery of the semi-rigid strap. In some configurations, the soft edging does not cover the front or rear faces of the semi-rigid strap and is instead attached adjacent to the edge of the semi-rigid strap. For example, the thicknesses of the soft edging and semi-rigid strap can be the same at the location where they are joined together. As used herein with respect to headgear and straps, "soft" is used to describe a hand of the material, which means the quality of the material assessed by the reaction obtained from the sense touch. In addition, as used herein with respect to headgear and straps, "conformable" is used to describe the ability of the material to conform to the anatomical features of the patient (e.g., around a facial feature). In particular, a strap including at least an element of "soft" and/or "conformable" material also may be "semi-rigid" and/or axially "non-stretchable. " The soft edging can have a uniform thickness, or in some configurations, an uneven thickness. For example, in some configurations the soft edging is the same thickness as the semi-rigid strap. In other configurations, the soft edging is thinner than the semi-rigid strap, forms a bulbous end to the semi-rigid strap, or is simply thicker than the semi-rigid strap. Any one particular soft edging thickness and shape can apply to a portion or the entire semi-rigid strap, or may be combined with any other particular covering thickness and shape. Many other thickness configurations may be provided, as well. In addition, material thickness may be symmetrically or asymmetrically applied to the semi-rigid strap. For example, in some configurations the thickness of either end the soft edging is symmetrically applied to the semi-rigid strap. In some configurations the semi-rigid strap is selectively thickened to provide extra rigidity and support. Finally, in some configurations, venting through-holes are provided throughout the semi-rigid headgear (such as on the semi-rigid strap or on soft edging) to provide ventilation and sweat management.

With reference to <FIG>, a magnetic repulsing system is shown that is adapted to be incorporated into a conduit for delivering respiratory gases to a user. The conduit is connectable to a mask or to a lead in tube to the mask and comprises an inlet, an outlet, and an enclosing wall defining at least one gases passageway between said inlet and said outlet. The magnetic repulsing system is incorporated into the enclosing wall to magnetically repulse a portion of the wall from a diametrically opposite portion of the wall. In particular, the magnetic repulsing system comprises one or more magnets that are spiral or helically shaped magnets. The arrangement of <FIG> has two spiral or helically shaped magnets of which one spirals in a clockwise direction <NUM> and the other spirals in a counterclockwise direction <NUM>. In an alternative arrangement, the magnetic repulsing system comprises a single spiral or helically shaped magnet. The inner surfaces <NUM> of the magnets that face each other are the same pole and repel each other. As a consequence, the repulsion prevents or at least substantially inhibits the conduit from being crushed or compressed.

With reference to <FIG>, a magnetic system according to another arrangement that is adapted to be incorporated into a conduit for delivering respiratory gases to a user, is shown. The magnetic system is arranged to magnetically collect, i.e. automatically retract and/or retain, a portion of a length of an enclosing wall of the conduit. In particular, the adjacent surfaces <NUM> of the magnets are the opposite poles and attract each other. As a consequence, the magnet collects a length of the conduit into a shorter length. The conduit may stretch, fold, or gather between the longer and shorter lengths. As the conduit, or a portion of the conduit, is stretched or pulled, the adjacent magnet portions will initially work against the pulling force and maintain the conduit in the shorter length. However, as the pulling force is increased, the magnetic force will be overcome and the conduit, or portion of the conduit, will have the longer length. <FIG> shows a portion of conduit in which the lower portion is collected by the magnetic coupling system and the upper portion is configured such that the adjacent magnetic portions are spaced at a distance that is greater than their fields reach so the conduit is not collected.

Claim 1:
A respiratory interface comprising:
a mask frame (<NUM>),
a seal module (<NUM>) configured to couple to the mask frame (<NUM>) and interface to a user's mouth and/or nose to deliver respiratory gases to the user, and
a magnetic coupling system arranged to magnetically couple the seal module to the mask frame,
wherein the magnetic coupling system comprises at least one magnet (<NUM>) associated with one of the seal module (<NUM>) or mask frame (<NUM>) and at least one other magnet or ferrous part (<NUM>) associated with the other of the seal module (<NUM>) or mask frame (<NUM>), and
wherein the magnet or magnets and corresponding ferrous part(s) (<NUM>) are elastically movably mounted such that they can move relative to the seal module (<NUM>) and/or frame (<NUM>),
characterized in that the magnet or magnets and corresponding ferrous part(s) (<NUM>) are mounted such that the seal module and mask frame will attract only in one predetermined orientation of the seal module relative to the mask frame and repel when the seal module is offered to the mask frame in any orientation other than the one predetermined orientation.