Patent Description:
Comfort and effectiveness remain a continuing challenge for engineers and designers of the interface between a mechanical ventilator and a patient. Such patient interfaces are currently employed for a variety of purposes including the delivery of non-invasive ventilation or for the delivery of pressurized air to persons who suffer from sleep disordered breathing conditions such as Obstructive Sleep Apnea (OSA). In non-invasive positive pressure ventilation, a supply of air at positive pressure is provided by a blower to a patient interface through an air delivery conduit. The patient interface may take the form of a nasal mask, nose & mouth mask, full face mask or nasal prongs.

A mask may comprise (i) a rigid or semi-rigid portion which attaches directly to the air delivery conduit and (ii) a soft patient contacting portion. The rigid or semi-rigid portion, known as a shell or frame, may define a nose-receiving cavity, or a mouth covering chamber. Other forms of patient interface, such as nasal cannulae, comprise a pair of nasal prongs, nasal inserts or nozzles.

The soft patient contacting portion is typically known as a cushion or membrane and is generally shaped during manufacture to match the facial contours of a patient in order to provide the optimum seal.

An inherent characteristic of patient interfaces such as nasal masks or nozzle assemblies is that they do not seal the mouth region. A number of patients thus find that during sleep when muscles relax, mouth leak may occur. Alternatively some patients are naturally mouth breathers and thus find a nasal patient interface ineffective. Mouth leak is undesirable as among other difficulties, it may result in noise, increased treatment pressure to compensate for the leak or an increased load on the nasal passages and potentially nasal obstruction or a runny nose.

Patient interfaces such as full face masks or nose and mouth masks address this issue by sealing, around both the nose and the mouth. Since nasal bridge anthropometry varies greatly between patients, the soft patient contacting portion or cushion must adapt to the shapes of individual patients. Typically this is not achieved for the entire range of patients and some form of leak occurs. The problem is heightened during sleep when the jaw moves and the head position changes. This action can often serve to dislodge the mask and cause leak. Since leak can be noisy and results in less-effective treatment, users often compensate by tightening the headgear more than is required. This is detrimental for patient comfort and can cause skin breakdown.

A further problem encountered by patients who are using full face, nasal or nose and mouth masks is that the portion of the patient interface that seals around the nasal bridge prevents the patient from wearing spectacles. Additionally it may give the sensation of being closed in, leading to a feeling of claustrophobia, particularly when combined with a mouth-sealing portion. A further disadvantage is that any leaks that may occur can affect the sensitive area surrounding the eyes.

One form of nasal assembly known as a nasal puff is described in <CIT>). This device has a pair of nasal puffs together with a plenum chamber held in place with a harness assembly adapted to be worn over the head of the patient. The device does not provide a mouth seal.

Another form of known nozzle assembly is described in <CIT>). The patent discloses a device with nares elements mounted on an inflatable plenum chamber. Again this does not provide any structure for sealing the mouth.

One typical example of a known nasal mask is described in <CIT>). This has a ballooning seal in order to fit the patient's nose and facial contours but does not provide a mouth seal.

International publication number <CIT>), describes a mask system for delivering air to a user including a suspension mechanism. This suspension mechanism allows relative movement between a face-contacting portion and a mask shell.

A known example of a full face mask is described in <CIT>). Whilst providing a facial contour and sealing mechanism that incorporates both the nasal and mouth, this mask cannot flex to adapt to changes in jaw movement and head position throughout the night.

A known example of a nose and mouth mask is described in <CIT>).

<CIT>) describes a mouthpiece which seals the oral cavity against 'mouth leak'. This mouthpiece includes both intra-oral and extra-oral sealing means and can be kept in place without the need for straps. International patent <CIT>) describes a similar mouthpiece for supplying humidified gases to a user.

<CIT>) describes an oral device for improving a patient's breathing together with a connecting post that provides a standard interface to a CPAP patient interface. The oral device is said to extend the lower jaw of the patient and thus open the breathing passage. The oral device is clenched between the teeth which may lead to discomfort and if mask pressures are high can lead to the slow creep of gums around the teeth due to the sustained load.

<CIT>) describes a cylindrical air chamber held in position by a mouth portion that extends between the lips and teeth. The mouth portion may prove irritating and lead to discomfort when used for long periods.

The following documents are also disclosing oro-nasal patient interfaces, <CIT>, <CIT> and <CIT>.

A problem with patient interfaces which incorporate oral appliances is that they can be uncomfortable for patients. Therefore, a need has developed in the art to address the problems of the prior art.

In accordance with a first aspect of the disclosure there is provided a comfortable, effective patient interface which provides a supply of air or breathable gas to a patient's nasal passages and which prevents or reduces mouth leak.

In accordance with a second aspect of the disclosure there is provided a patient interface which can accommodate movement of the jaw of the patient.

In accordance with another aspect of the disclosure there is provided a patient interface that provides an effective seal with both the patient's mouth and the patient's nasal passages.

In one form the disclosure comprises a mouth covering chamber, a nozzle assembly and a structure to provide flexibility therebetween.

Another aspect of the disclosure relates to reducing contact area when compared to most known full face masks. This allows a far reduced headgear tension to be applied, significantly improving patient comfort. Patient comfort is further enhanced since the patient is less likely to feel claustrophobic, particularly with the removal of any mass that is close to the eyes.

In accordance with another aspect of the disclosure there is provided a patient interface adapted to connect to an air delivery conduit.

In accordance with another aspect of the disclosure there is provided a patient interface comprising a first chamber which incorporates a mouth covering chamber, a second chamber which incorporates a nozzle assembly and a flexible element connecting the first and second chambers.

In accordance with another aspect of the disclosure there is provided a patient interface comprising a mouth covering chamber, a pair of nozzles and a flexible attachment member therebetween.

In accordance with yet another aspect of the disclosure there is provided a patient interface comprising a mouth covering chamber and a pair of nozzles flexibly attached thereto. The mouth covering chamber incorporates a rigid portion defining the mouth covering chamber and a resilient or compliant patient-contacting portion. The pair of nozzles are mounted upon the patient-contacting portion.

In accordance with yet another aspect of the disclosure there is provided a patient interface comprising a mouth receiving assembly and a pair of nozzles flexibly attached thereto. The mouth receiving assembly incorporates a rigid portion defining a mouth covering chamber, a gusset portion and a patient-contacting portion. The pair of nozzles are mounted upon a flexible component of the patient-contacting portion.

In accordance with yet another aspect of the disclosure there is provided a patient interface with a strap routed around the top of the ears.

These and other aspects of the disclosure will be described in or apparent from the following detailed description of preferred embodiments, in which like elements designate like parts.

<FIG> illustrate a first embodiment of the present disclosure. As shown in <FIG>, a headgear assembly <NUM> includes a patient interface having a dual chamber assembly <NUM> including an upper chamber <NUM> and a lower chamber <NUM>. As shown in <FIG>, the lower chamber <NUM> is in a disconnected position, while <FIG> shown the upper and lower chambers in a connected position.

Referring to <FIG>, the upper chamber <NUM> includes a nozzle assembly <NUM> supported by a frame including a first connector on each lateral end thereof, as described in <CIT>. The nozzle assembly <NUM> is secured to the frame via a clip <NUM> which in this embodiment supports a pressure measurement port <NUM>. The nozzle assembly <NUM> may include a pair of nozzles <NUM> (see <FIG> and <FIG>).

One or more inlet conduits <NUM> is supplied with breathable gas under pressure via a joint <NUM> coupled to an air delivery tube, which in turn is communicated with a blower or air delivery device. The lower chamber <NUM> is connected to the joint <NUM> via an inlet conduit <NUM>. The joint <NUM> may include three branches (see <FIG>) for connection to the inlet conduits <NUM> and <NUM>.

Each inlet conduit <NUM> is connected to an elbow connector <NUM>, which is preferably connected to yoke <NUM> of strap <NUM> of headgear assembly <NUM> via a locking portion <NUM>. Each elbow connector <NUM> is coupled to a second connector <NUM>. Each respective first connector of the frame may be selectively rotated with respect to the second connectors <NUM> to allow the nozzle assembly <NUM> to be adjusted according to patient requirements, to achieve the best fit.

As best shown in <FIG>, where the upper and lower chambers are disassembled, a first portion <NUM> of the lower chamber <NUM> maybe connected to a second portion <NUM> of the upper chamber <NUM>. Connection may be achieved via a conduit <NUM> (See <FIG>), or preferably a flexible element that connects the upper chamber <NUM> to the lower chamber <NUM>. The flexible element may comprise one or more thin silicone conduits through which air can pass. It may take the form of any other flexible element through which air can pass however, examples including a spring <NUM> (Fig. If), bellows <NUM> (<FIG>) or piston mechanism <NUM> (Fig. lh). The flexible element provides a range of adjustment to adapt to the different geometry of a wide range of patients and in addition allow for any movement of their jaw and head position during sleep. The conduit need not be flexible if adjustment can occur via flexibility of the cushions of the upper and lower chambers.

Connection between the upper and lower chambers may take several forms, keeping in mind that one main purpose is to maintain the position of the upper chamber <NUM> relative to the patient's mouth. To that end, the connection may take the form of a mechanical fastener, such as VELCRO®, snaps, connectors, etc. For example, the top or second portion <NUM> of the upper chamber <NUM> may include a hook portion of VELCRO®, while the bottom or first portion <NUM> of the upper chamber <NUM> may include the loop portion of VELCRO®. In other forms, the connection may be provided via metal or plastic rivets and/or by use of adhesives. In the case of rivets, flexibility could be provided by virtue of the compliant and flexible portions of the cushions of the respective upper and lower chambers that are fastened together. In other forms, the lower chamber <NUM> may be connected to a portion of the headgear, or to the inlet tubes <NUM>. Moreover, it is not necessary that air can pass between the upper and lower chambers <NUM>, <NUM>, as each has an independent source of pressurized air.

As shown in <FIG>, the lower chamber <NUM> includes a rigid polycarbonate frame <NUM> which defines a mouth covering chamber <NUM> (see <FIG>) and a soft (e.g., compliant, resilient) silicone cushion <NUM> which contacts the patient and forms a seal. The lower chamber <NUM> closely resembles the mouth chamber and mouth cushion described in <CIT>. However it may take a variety of forms, such as described in <CIT>. The cushion <NUM> may be attached to the frame <NUM> by connecting a base edge of the cushion <NUM> to the frame <NUM>, e.g., via adhesives and/or a tongue and groove arrangement. In another form, connection may be achieved by stretching the cushion <NUM> over the outer edge of the frame <NUM>.

The inlet conduit <NUM> is structured to deliver breathable gas into the lower chamber <NUM>. The inlet conduit <NUM> may be inserted into an aperture of the frame <NUM>, in which case the tube <NUM> may be held in place by friction alone, as best shown in <FIG> and ld. Alternatively, the inlet conduit <NUM> may be connected to a swivel assembly (not shown) which in turn is connected to the frame <NUM>. In another alternative, one or more suitable headgear straps (not shown) can be used to support the lower chamber <NUM> such that it can move or pivot relative to the upper chamber without the need for connection thereto or a flexible element.

<FIG> and <FIG> show a second embodiment of the disclosure. In this embodiment, the lower chamber <NUM> does not have a direct inlet conduit, like the inlet conduit <NUM> in <FIG>, but instead the air is directed to the upper chamber <NUM> via the inlet conduits <NUM> only. Air travels through the flexible element, i.e., through first and second surfaces <NUM> and <NUM>, from the upper chamber <NUM> to the lower chamber <NUM>, for example, thus allowing both nose and I mouth breathing. <FIG> best showed the position where the flexible element would be located between the first and second surfaces <NUM>, <NUM>.

<FIG> shows one example of how the upper and lower chambers <NUM>, <NUM> may communicate with one another. A mechanical fastener <NUM> includes first and second parts <NUM> and <NUM>. The first part <NUM> may take the form of a thin plate attached to an inside surface 37a of the second part <NUM> formed on the upper chamber <NUM>. The first part includes an aperture <NUM>. The second part <NUM> may include a thin plate positioned on the inside surface 36a of the first part <NUM> formed on the lower chamber <NUM>. The second part <NUM> includes one and preferably a plurality of arms <NUM> extending through the upper and lower chambers <NUM>, <NUM>. The arms <NUM> are resiliently flexible so that shoulder <NUM> on each arm <NUM> may be secured against a top surface 92a of the first part, thereby locking the entire assembly together while allowing gas to flow between the upper and lower chambers <NUM>, <NUM>. The arms <NUM> may be formed so as to cut through the upper and lower chambers <NUM>, <NUM> upon assembly, thereby creating the through hole. The assembly may provide for multiple holes if desired.

In <FIG> and <FIG>, a plug <NUM> covers an aperture of the frame <NUM> where an inlet conduit could be placed. Therefore, the joint <NUM> in <FIG> need not include a separate branch for the conduit <NUM>, or the branch could be plugged.

In a third embodiment of the disclosure, as shown in <FIG> and <FIG>, inlet air is directed directly to the lower chamber <NUM> through a swivel assembly <NUM>. The upper chamber <NUM> does not have any inlet conduits but instead the air is directed to the upper chamber <NUM> by traveling through a conduit extending from the first surface <NUM> to the second surface <NUM>. The use of a swivel assembly <NUM> has the advantage that the inlet conduit (not shown, but connected to end <NUM> of swivel assembly <NUM>) can be routed from any direction. Further, nozzle assembly <NUM> need not be provided with second connectors <NUM> and elbow connectors <NUM> as shown in <FIG>. Instead, a pair of plugs <NUM> may be placed into each end of the nozzle assembly <NUM>, as described in <CIT> and entitled "Nasal Assembly".

<FIG> schematically show a fourth embodiment of the invention. In this embodiment, the mouth covering chamber <NUM> and the nozzle assembly <NUM> form one chamber with inherent flexibility of the soft silicone cushion <NUM> upon which the nozzles <NUM> are mounted providing for movement and changes in alignment between the two. This embodiment of the invention achieves the advantage of minimizing the volume of the patient interface which is positioned between the nares and the upper lip.

<FIG> illustrate yet another embodiment of the disclosure. As can be seen from <FIG>, a swivel assembly <NUM> provides air from an air delivery tube (not shown) and supplies it to the mouth covering chamber <NUM> (best shown in <FIG>). The cushion <NUM> is connected to the rigid frame <NUM> of the mouth covering chamber <NUM> via a cushion clip <NUM>. As best shown in <FIG>, the nozzles <NUM> are connected or provided directly to the outer face contacting portion of the cushion <NUM> which takes the form of a thin silicone membrane <NUM>. The membrane <NUM> performs the dual function of forming a seal around the lips of a patient and additionally supporting the nozzles <NUM>. The inherent flexibility of the membrane <NUM> provides a range of adjustment to adapt to the different geometry of a wide range of patients and in addition allows for any movement of their jaw and head position during sleep. It should be noted that whilst this embodiment describes nozzles <NUM> of a similar form to those disclosed in <CIT>, they may take the form of any nasal prongs insertable into each nare. As shown in <FIG>, the patient interface can easily be attached via clips <NUM> to a headgear assembly <NUM> in order to secure the patient interface to the patient. The headgear <NUM> includes an intermediate strap 31a extending between clip <NUM> and connector <NUM>. The clip <NUM> and its connection to frame <NUM> resemble the clip/frame described in <CIT>.

<FIG> schematically illustrate a fifth embodiment of the invention. In this embodiment the patient interface includes a mouth covering chamber <NUM> incorporating a rigid frame <NUM>, a gusset portion <NUM> and a soft cushion <NUM>. The nozzles <NUM> are connected directly to the outer face contacting portion of the cushion <NUM> which takes the form of a thin silicone membrane <NUM>. The gusset portion <NUM> includes a flexible membrane and has a first side attached to the frame <NUM> and a second side attached to the cushion <NUM>, as shown in <FIG>. Pressure within the patient interface acts upon the increased surface area of the gusset portion <NUM> projected on the patient's face so as to provide a sealing force for the soft cushion <NUM> against the patient's face. In addition the gusset portion <NUM> acts to effectively isolate or decouple the rigid frame <NUM> from the soft cushion <NUM>. In these respects, the gusset portion <NUM> acts in a similar manner to that described in International publication number <CIT>).

Due to its location between the cushion <NUM> and the frame <NUM>, the gusset portion <NUM> also acts to decouple the nozzles <NUM> mounted upon the soft cushion <NUM> from the rigid frame <NUM>. This provides further flexibility within the patient interface which has the advantages previously described of allowing the interface to adjust to the geometry of different patients and allowing for any jaw or head movement during sleep. A further advantage of the gusset portion <NUM> is that it allows the face contacting portion, e.g., membrane <NUM>, of the cushion <NUM> increased freedom to deform in accordance with the contours of the mouth region than does a direct connection between the cushion <NUM> and rigid frame <NUM>. Thus the cushion <NUM> may "wrap around" the mouth region as required.

The gusset portion <NUM> of the embodiment shown in <FIG> is a partial gusset portion in that it is arranged at the chin portion of the mouth covering chamber <NUM>. Alternatively the gusset portion <NUM> may fit around the entire circumference of the rigid frame <NUM>. An embodiment of this is shown in <FIG>. As can be seen from <FIG>, the embodiment includes an inlet swivel assembly <NUM>, a frame <NUM>, a gusset portion <NUM> and a soft cushion <NUM> with nozzles <NUM> mounted thereon.

<FIG> shows the components disassembled, although the swivel assembly <NUM> and frame <NUM> are shown in an assembled state that could be disassembled in an alternative embodiment. The headgear clips <NUM>, cushion clip <NUM> and cushion <NUM> with gusset portion <NUM> can also be seen in <FIG>. The clip <NUM> may include one or more resilient tabs <NUM> that engage with corresponding recesses <NUM>, one of which is shown on frame <NUM>.

Two alternative cushions, 42A and 42B without gussets are displayed in <FIG>. It should be noted that each of the nozzles <NUM> on cushion 42B includes a simple mound rather than containing a single flexible pleat as do the nozzles on cushion <NUM> and cushion 42A. The nozzles <NUM> may also include a plurality of corrugations and in general the nozzles may take the form of a nasal puff as described in <CIT>), or as in other known nasal cannulae, such as prongs that extend into the nares. Further nozzle alternatives are described in <CIT> and entitled "Nasal Assembly.

<FIG> show an alternative embodiment of a patient interface assembled to a headgear assembly <NUM> via clip <NUM> that is selectively adjustable in a rotational sense with respect to yoke <NUM> attached to strap <NUM>, as described in <CIT>. Each clip <NUM> includes opposed arms <NUM> that may resiliently flex towards one another to allow engagement and disengagement of claws <NUM> formed on arms <NUM>. The claws <NUM> may lockingly engage with corresponding structure or a receptacle <NUM> formed on or as part of frame <NUM>. In this embodiment, the receptacle <NUM> may be moved, flexed or pivoted with respect to a portion 38a of the frame <NUM>, e.g., along pivot axis <NUM>. <FIG> shows the clips <NUM> in different angular positions.

<FIG> is an exploded view of clip <NUM>, receptacle <NUM> and portion 38a of frame <NUM>. The portion 38a may be attached to (e.g., via glue) or formed as an integral part of the frame <NUM>. The receptacle <NUM> includes side chambers 68a for receiving claws <NUM> and a central chamber 68b for receiving central tab <NUM> of clip <NUM>. The receptacle <NUM> may be attached to portion 38a, e.g., via a pin and slot assembly. For example, the receptacle <NUM> may include opposed arms <NUM> each including a pin <NUM>. Each pin <NUM> can be received within an end <NUM> of a C-shaped channel <NUM>. At least one of the arms <NUM> or the C-shaped channel <NUM> may flex to allow assembly and disassembly. Of course, other arrangements for allowing relative movement are possible.

Alternative headgear may be used, i.e., this embodiment is not limited to the headgear assembly shown in <FIG>. Vents <NUM> for the removal of excess carbon dioxide are shown in <FIG>. The vents <NUM> may be formed on an elastic insert, as described in <CIT>. <FIG> shows an enlarged patient-side view of the cushion <NUM> in isolation.

<FIG> shows an alternative form of headgear with an occipital strap <NUM>, a coronal strap <NUM> and a depending strap <NUM> that is routed to the top of the ears. The headgear straps <NUM>, <NUM>, <NUM> may be rigid or may be constructed from a laminated foam material such as Breath-O-Prene™. In one form the headgear straps may be constructed from a combination of a soft comfortable material, such as Breath-O-Prene and a stiffening yoke <NUM> constructed from a polymer, such as nylon, as described in International Patent Application <CIT>. Angular adjustment between the rigid frame <NUM> and the headgear, such as that may be achieved via the arrangement shown in <FIG>.

<FIG> show the patient interface supported by spectacles-type headgear <NUM>. One strap <NUM> is used as a hook mechanism behind the ear. The strap <NUM> may be extended to wrap around the head and apply a force inwards towards the head, as shown in <FIG>, or the wrap around portion may be eliminated as shown in <FIG>. <FIG> shows an additional stabilizing band <NUM> around the neck. The headgear straps may be formed of any suitable material such as textile, plastic or semi-rigid assemblies. The headgear assembly has the advantage that it covers the minimum head area and therefore is more comfortable than many traditional designs. In order to improve patient comfort, the headgear may also require adjustment to suit the head circumference and ear height. It may also be applied to alternative forms of patient interface such as nasal prongs or nose masks.

<FIG> illustrate another embodiment of a patient interface. As illustrated, the patient interface includes a cushion <NUM> and a pair of nozzles <NUM> flexibly mounted to the cushion <NUM>. The patient interface is formed as a one-piece structure such that the cushion <NUM> is integrally formed in one-piece along with the nozzles <NUM>. For example, the cushion <NUM> and nozzles <NUM> may be formed in an injection molding process as is known in the art. Also, the cushion <NUM> and nozzles <NUM> form one chamber with flexibility between the cushion <NUM> and nozzles <NUM> to provide for movement and changes in alignment between the two.

The cushion <NUM> includes a non-face-contacting portion and a face-contacting portion. The non-face-contacting portion is structured to be removably and replacably attached to a rigid frame associated with the air delivery tube. The non-face-contacting portion may be removably and replacably attached to the frame in any suitable manner, e.g., cushion clip, friction or interference fit, and/or tongue-and-groove arrangement, as is known in the art. However, the non-face-contacting portion may be permanently attached to the frame, e.g., by glue and/or mechanical fastening means.

As best shown in <FIG> and <FIG>, the face-contacting portion of the cushion <NUM> includes a side wall <NUM>, a pair of underlying support rims <NUM> extending away from the side wall <NUM>, and a membrane <NUM> provided to substantially surround the rims <NUM> and provide a sealing structure for the face contacting portion. The side wall <NUM> and rims <NUM> provide a support structure for the face contacting portion. Also, as best shown in <FIG>, the face-contacting portion is contoured to follow generally the curvature of the patient's face.

The membrane <NUM> is structured to form a seal around the lips of a patient. In the illustrated embodiment, the membrane <NUM> has a substantially flat profile. In use, the edge <NUM> of the flat-profiled membrane <NUM> is the first point of contact with the patient's face. As the membrane <NUM> comes more into contact with the patient's face, the membrane <NUM> conforms to the patient's face with good contact at the inner edge <NUM> thereof, which reduces the possibility of pressurized air coming between the skin and the edge <NUM>, thereby improving the integrity of the seal. Also, the edge <NUM> of the membrane <NUM> contacts the face and fully extends or stretches the membrane <NUM>, thereby eliminating any wrinkles. A more rounded membrane profile provides a tangential contact with the patient, potentially providing a leak path under the membrane when air pressure is applied. Further, the membrane <NUM> extends further than the edges of the rims <NUM> to prevent the rims <NUM> from being a source of irritation (e.g., see <FIG>).

The inner edge of the membrane <NUM> defines an aperture <NUM> that receives the patient's lips. As best shown in <FIG>, the aperture <NUM> has a generally oval shape. However, the aperture <NUM> may have any other suitable shape to accommodate variations in the shape of a patient's mouth.

For example, <FIG> illustrate another embodiment of a patient interface. Similar elements are indicated with similar reference numerals. As illustrated, the upper edge of the aperture <NUM> has an arcuate protruding portion. Also, as shown in <FIG> and <FIG>, the upper side of the side wall has an arcuate configuration that corresponds with the arcuate configuration of the upper edge of the aperture <NUM>. Thus, the plan profile of the cushion <NUM> shown in <FIG> and <FIG> is curved and has a shape similar to a smile. This configuration helps stability by more closely following the patient's facial geometry and prevents roll since the cushion <NUM> is higher at the sides. That is, the cushion shown in <FIG> has a greater height than the cushion shown in <FIG>, which helps with stability. However, the shorter height of the cushion shown in <FIG> has a shorter profile and is therefore less obtrusive to the patient. For example, the cushion in <FIG> may have a height of about <NUM> and the cushion in <FIG> may have a height of about <NUM>. However, the cushion may have any other suitable height. The cushion <NUM> also has a membrane <NUM> with a substantially flat profile (e.g., see <FIG>), which provides an enhanced seal as described above.

As best shown in <FIG>, the rims <NUM> are preferably provided on lateral sides of the side wall only <NUM>. The rims <NUM> add rigidity to the membrane <NUM> at the sides of the patient's mouth or cheeks. As illustrated, each rim <NUM> has a general C-shape and extends inwardly into the cavity of the cushion <NUM>. While it is preferable that the membrane <NUM> be thinner than the rim <NUM>, they could have the same thickness. For example, in <FIG>, <FIG>, the side wall thickness may be about <NUM>, which tapers to about <NUM> at the edges of the membrane. In <FIG> and <FIG>, the side wall thickness may be about <NUM>, which tapers to about <NUM> at the edges of both the rim and the membrane. However, the side wall, rim, and membrane may have any other suitable thicknesses.

As shown in <FIG>, the inside surface of the membrane <NUM> is spaced from the outside surfaces of the rims <NUM> so that the membrane <NUM> can accommodate small variations in the shape of the patient's mouth without undue force and can account for small movement of the patient interface relative to the patient during use, while maintaining an effective seal. The spacing between the rim <NUM> and the membrane <NUM> may have any suitable size. Moreover, the rim <NUM> may extend around the entire perimeter of the side wall, or may have any other suitable configuration to support the membrane <NUM>.

In the illustrated embodiment, the face-contacting portion of the cushion <NUM> has a double-walled construction, i.e., membrane and rim, in the region of the cheeks and a single-walled construction, i.e., membrane, under the nozzles <NUM> and in the region of the chin and/or lower lip. The single wall construction at the top and bottom of the cushion <NUM> helps to accommodate high landmarks, e.g., pointed chin, by allowing the center of the cushion <NUM> to flex. This flexibility accommodates more patients with the same cushion <NUM>. Also, the single wall construction under the nozzles <NUM> alleviates space constraints and potential occlusion of the nasal air path by a rim. However, the cushion <NUM> may have any other suitable construction, e.g., single walled, triple walled or more walled construction, in any suitable region of the cushion <NUM>, e.g., cheek, chin, under nozzles. For example, <FIG> illustrates an embodiment of a patient interface substantially similar to the patient interface shown in <FIG>. In contrast, the patient interface includes a rim <NUM> that extends around the entire perimeter of the cushion <NUM> as indicated by the dashed line. Also, the rim <NUM> could be completely removed. <FIG> illustrates an embodiment of a patient interface substantially similar to the patient interface shown in <FIG> (nozzles omitted for clarity purposes). In contrast, the side wall <NUM> of the cushion <NUM> has a slightly different perimeter geometry. The cushion <NUM> also has a membrane <NUM> with a substantially flat profile (e.g., see <FIG>), which provides an enhanced seal as described above.

The side wall of the cushion <NUM> supports the pair of nozzles <NUM>. Similar to the above embodiments, the nozzles <NUM> may have a similar form to those disclosed in <CIT>, however they may take the form of any nasal prongs insertable into each nare.

As illustrated, each nozzle <NUM> includes a conduit <NUM> that interconnects each nozzle <NUM> with the cushion <NUM> and allows breathable gas to pass from the chamber defined by the cushion <NUM> to the nozzles <NUM>. As shown in <FIG>, <FIG> and <FIG>, the conduits <NUM> and nozzles <NUM> attached thereto are angled with respect to the side wall to properly position the nozzles <NUM> with the nasal passages of the patient. For example, the angle θ in <FIG> and <FIG> is referred to as the alar angle, the angle α in <FIG> and <FIG> is referred to as the nostril angle, and the angle β in <FIG> and <FIG> is referred to as the naso-labial angle. As illustrated, the angle θ is substantially the same in <FIG> and <FIG>, the difference being that the angle θ in <FIG> is defined by the nozzles <NUM> whereas the angle θ in <FIG> is defined by the side wall <NUM>. The angles θ, a, and β may have any suitable value and may be determined from anthropometric data. For example, the angle θ may be between <NUM>°-<NUM>°, the angle α may be between <NUM>°-<NUM>°, and the angle β may be between <NUM>°-<NUM>°. These angles are merely exemplary and should not be limiting. Also, the nozzles <NUM>, conduits <NUM>, and side wall <NUM> may have any suitable configuration to properly position the nozzles <NUM> with respect to the nasal passages of the patient.

Also, the conduits <NUM> may have different lengths to accommodate different patients. For example, the conduits <NUM> illustrated in <FIG> are longer than the conduits <NUM> illustrated in <FIG>. The longer conduits of <FIG> provide more nozzle flexibility, whereas the shorter conduits of <FIG> allow more direct transfer of forces from the side wall support to the nozzles. The conduits <NUM> may have any suitable length and may be suitably varied to accommodate various patients, e.g., with varying length between the patient's nose and upper lip. For example, in an embodiment, the nozzles <NUM> are about <NUM> long, which allows good flexibility and articulation while still allowing the nozzles <NUM> to be loaded adequately to effect seal.

<FIG> illustrate an embodiment of a patient interface wherein the nozzles have been removed so that the patient interface includes a cushion <NUM> only. The cushion <NUM> may have a structure similar to the cushions described above, e.g., side wall <NUM>, a pair of rims <NUM> extending away from the side wall <NUM> in the cheek regions, and a membrane <NUM>. However, the cushion <NUM> may have any other suitable structure to seal around a patient's mouth.

<FIG> illustrate embodiments of a patient interface that include a cushion <NUM> and a pair of nozzles <NUM> that are blocked from fluid communication with the chamber defined by the cushion <NUM>. In <FIG>, the nozzles <NUM> are blocked at entrance to the cushion <NUM>. That is, the upper portion of the side wall <NUM> is not provided with any openings that communicate with the nozzles <NUM>. In <FIG>, the nozzles <NUM> are blocked at the nozzle tips. That is, the nasal opening of the nozzle <NUM> is blocked so that gas cannot pass through the nozzles <NUM>. The pressure within the nozzles <NUM> aids the seal within the nasal passages of the patient. In another embodiment, a set of plugs may be inserted into the nozzles <NUM>, e.g., at the top or bottom of the nozzles, to block nasal flow. In these embodiments, the nozzles <NUM> simply seal the patient's nasal passages, and gas is delivered to the patient's mouth only. The blocked nozzles may also serve to stabilize the cushion and help with alignment.

<FIG> illustrate an embodiment of a patient interface that includes a cushion <NUM> and a pair of nozzles flexibly mounted to the cushion <NUM> (nozzles omitted for clarity purposes). As illustrated, the cushion <NUM> includes a side wall <NUM> incorporating a gusset portion <NUM>, a pair of rims <NUM> extending away from the side wall <NUM>, and a membrane <NUM> to substantially surround the rims <NUM> and provide a sealing structure for engagement with the patient's face.

Similar to the embodiments in <FIG>, the rims <NUM> are provided on the lateral sides of the side wall <NUM> only (e.g., see <FIG> and <FIG>). However, a rim may be provided around the entire perimeter of the side wall, or at any other suitable portion of the side wall, e.g., chin portion of the cushion. Also, similar to the embodiments in <FIG>, the side wall thickness may be about <NUM>, which tapers to about <NUM> at the edges of both the rim and the membrane. The thickened side wall helps to support the nozzles in proper position.

As best shown in <FIG>, <FIG>, the gusset portion <NUM> is provided on the lateral sides of the side wall <NUM> and the lower wall of the side wall <NUM> (adjacent the patient's chin). However, the gusset portion <NUM> may be provided around the entire perimeter of the side wall. Similar to the gusset portion described above in <FIG>, for example, the gusset portion <NUM> provides further flexibility within the patient interface to allow the interface to adjust to the geometry of different patients, allow for any jaw or head movement during sleep, and allow the membrane <NUM> of the cushion <NUM> increased freedom to deform in accordance with the contours of the mouth region without disturbing nozzle seal. Also, the gusset portion <NUM> could be replaced by a flexible spring, or any other suitable structure that would add flexibility.

<FIG> illustrate embodiments of a patient interface that include a cushion <NUM> and a pair of nozzles <NUM> that are selectively mounted to the cushion <NUM>. Specifically, the nozzles <NUM> are formed separately from the cushion <NUM>, and then secured to the cushion <NUM> to construct a patient interface with both cushion <NUM> and nozzles <NUM>. This arrangement provides a greater scope of patient fitting by being able to select cushion size and nozzle size independently. Also, the nozzles <NUM> may be independently aligned with respect to the cushion <NUM> for optimal fit.

In each of the embodiments, each nozzle <NUM> includes a nozzle portion <NUM> that seals within a respective patient nasal passage and a base portion <NUM> that is mountable to the cushion <NUM>. The side wall of the cushion <NUM> includes nozzle mounting portions <NUM> structured to mount a respective nozzle <NUM>.

The nozzles <NUM> may be mounted to the cushion <NUM> in any suitable manner. For example, <FIG> illustrates an arrangement wherein the nozzle mounting portions <NUM> are in the form of inclined platforms <NUM> structured to support a respective nozzle <NUM> thereon. The base portion <NUM> of the nozzles <NUM> may be secured to respective platforms <NUM> in any suitable manner, e.g., adhesive, male/female connection, etc..

<FIG> illustrates an arrangement wherein the nozzle mounting portions <NUM> provide substantially flat mounting surfaces structured to support a respective nozzle <NUM> thereon. The base portion <NUM> of the nozzles <NUM> are secured to respective surfaces via a male/female connection mechanism. For example, each base portion <NUM> may include a protrusion that is secured within a respective opening provided in the respective nozzle mounting portion <NUM> of the cushion <NUM>. However, the nozzles <NUM> may be secured to the cushion <NUM> in any other suitable manner.

<FIG> illustrates an arrangement wherein the nozzle mounting portions <NUM> are in the form of cylindrical protrusions structured to engage within openings provided in the base portion <NUM> of respective nozzles <NUM>. However, the nozzles <NUM> may be secured to the cushion <NUM> in any other suitable manner.

As shown in <FIG>, the nozzles <NUM> are mounted to the cushion <NUM> such that the nozzles <NUM> can rotate independently to align each nozzle <NUM> with a respective one of the patient's nares. As shown in <FIG>, a ball-jointed insert <NUM> may be incorporated into the nozzles <NUM> to allow greater rotational and angular freedom and allow alignment in all directions. As shown in <FIG>, the cushion <NUM> may include angular alignment marks <NUM> to align the nozzles <NUM> with respect to the cushion <NUM>, which assists the patient in consistent setup. The marks <NUM> may have any suitable configuration, e.g., detented.

<FIG> illustrates an arrangement wherein each nozzle mounting portion <NUM> provides an opening defined by edges having a stepped configuration. The base portion <NUM> of each nozzle <NUM> has an annular recess that receives the stepped edge of the opening therein, so as to secure each nozzle <NUM> within the respective opening. The stepped edge may include one or more resilient protrusions (in dashed lines) to improve the seal between the cushion <NUM> and nozzles <NUM>. Also, the stepped edge may have multiple steps to allow for selective height adjustment. However, the nozzles <NUM> may be secured to the cushion <NUM> in any other suitable manner. Also, the nozzle <NUM> illustrated in <FIG> includes a gusset portion <NUM> that adds flexibility and articulation of the nozzle <NUM> with respect to the cushion <NUM>. It should be understood that one or more gusset portions <NUM> may be provided on each nozzle <NUM>, and the gusset portion <NUM> may have any suitable configuration to improve nozzle flexibility.

The embodiments of <FIG> allow nozzles <NUM> to be interchanged for different size patient nares, which improves seal and patient comfort. Also, it should be understood that the nozzles <NUM> could be interchanged individually, or a single insert could be provided that contains both nozzles <NUM>.

<FIG> illustrate embodiments of a patient interface that include a pair of nozzles <NUM> that are mounted to a mouth appliance <NUM>, e.g., an appliance that sits within a patient's mouth. In the illustrated embodiment, the mouth appliance <NUM> provides a mouth seal by sandwiching the inside and outside of the patient's mouth. Specifically, the mouth appliance <NUM> includes a tongue depressor <NUM>, a soft seal <NUM> that abuts against the inner surface of the patient's mouth, and a snap flap <NUM> that abuts against the outer surface of the patient's mouth to provide an endstop against the appliance being swallowed. An example of such mouth appliance is disclosed in <CIT>. The nozzles <NUM> are mounted to the mouth appliance <NUM> by a conduit <NUM> that allows gas to pass between the mouth appliance <NUM> and nozzles <NUM>. The conduit <NUM> may have a flexible or rigid construction. As shown in the embodiment of <FIG>, a mask system <NUM>, e.g., similar to a diving mask, may be incorporated into the patient interface to improve seal and to help locate the nozzles <NUM> with respect to the patient's nasal passages. Also, the tongue depressor <NUM> is optional and may be removed.

<FIG> illustrate an embodiment of a patient interface having a corrugated frame <NUM> and a cushion (not visible) with nozzles <NUM> mounted to the frame <NUM>, or to the cushion. The corrugations in the frame <NUM> add flexibility to the frame <NUM> to allow the frame <NUM> to adjust to the facial geometry of different patients and to allow for any jaw or head movement during sleep. For example, the frame <NUM> may move downwardly for jaw dropping during sleep, and may move rearwardly for receding jaw (see arrows in <FIG>). As illustrated, the corrugations are provided along a lower portion of the frame <NUM>. However, the corrugations may extend across the entire frame <NUM>. The movement may be accomplished via pivoting and/or sliding action of the corrugated frame about the sides of the frame. In this arrangement, the seal in the lower lip region is thus not compromised even if the jaw moves. Also, frame flexibility may be provided by other suitable structures, e.g., gusset portion provided in the frame. The frame <NUM> may be adjusted, e.g., by adjusting the tension in the lower straps of a headgear assembly <NUM>. Further, the corrugated configuration may be incorporated into a full-face mask.

Also, the frame <NUM> is structured such that inlet conduits <NUM> are coupled to the sides of the frame <NUM> for delivering breathable gas into the patient interface. However, one or more inlet conduits <NUM> may be coupled to the frame <NUM> in any other suitable manner, e.g., to the front of the frame.

<FIG> illustrate embodiments of patient interfaces including a cushion <NUM> and a pair of nozzles <NUM> mounted to the cushion <NUM>. The nozzles <NUM> are mounted to the cushion <NUM> to add flexibility to the nozzles <NUM> with respect to the cushion <NUM>. For example, <FIG> illustrates nozzles <NUM> mounted within respective rounded recesses <NUM> or scalloped reliefs provided in the side wall of the cushion <NUM>. The depth of the recess <NUM> may be suitably modified to provide desired variations of flexibility. For example, the recesses <NUM> may be relatively deep for greater flexibility as shown in <FIG>, or the recesses <NUM> may be relatively shallow for moderate flexibility as shown in <FIG> illustrates an embodiment wherein a radial notch <NUM> is provided in the conduit <NUM> that interconnects each nozzle <NUM> with the cushion <NUM>. The notch <NUM> adds flexibility to the conduit <NUM> which facilitates movement of the nozzle <NUM> with respect to the cushion <NUM>.

<FIG> illustrate embodiments of nozzles <NUM> having a nozzle portion <NUM> and a conduit <NUM> that interconnects the nozzle portion <NUM> with the side wall of the cushion <NUM>. As illustrated, the cross-sectional configuration of the conduit <NUM> may be varied to vary the flexibility of the nozzle <NUM>. For example, <FIG> illustrate an embodiment wherein the conduit <NUM> has a substantially constant cylindrical cross-sectional configuration along its length. <FIG> illustrate an embodiment wherein the cross-sectional configuration of the conduit <NUM> varies along its length. As illustrated, the conduit <NUM> has an elliptical cross-sectional configuration near the nozzle portion <NUM> which continuously varies to a cylindrical cross-sectional configuration near the side wall of the cushion <NUM>. Thus, the conduit has a "swept" cross-sectional configuration. In other embodiments, the nozzles <NUM> may include anatomically-shaped nozzle portions, and the nozzle portions may include openings that are off-center from the conduit opening. Preferably, the cross-sectional shape of the conduit and the nozzle opening are similar or the same, although dissimilar shapes are also possible. Also, the nozzles <NUM> may be structured to dilate the patient's nose similar to the structure shown in <FIG> of <CIT>.

<FIG> illustrate an embodiment of a patient interfaces including a cushion <NUM> and a pair of nozzles <NUM> mounted to the cushion <NUM>. As illustrated, the nozzle conduits <NUM> have a concertina configuration, e.g., accordion-like, which adds flexibility to the nozzles <NUM> with respect to the cushion <NUM>. Specifically, the concertina configuration allows both rotational and vertical adjustment of the nozzles <NUM> with respect to the cushion <NUM>. For example, <FIG> shows a nozzle <NUM> in a neutral position, and <FIG> shows a nozzle <NUM> stretched and rotated with respect to the cushion <NUM>. The concertina configured conduit <NUM> may be constructed from a soft silicone material or a stiffer material, e.g., drinking straw material, to allow articulation and extension. This configuration allows the conduits to be adjustably positioned in a number of different positions, and maintained in position during use. Also, the nozzles <NUM> may be integrally formed in one-piece along with the cushion <NUM>, or the nozzles <NUM> may be formed separately from the cushion <NUM> and mounted thereto.

<FIG> illustrate embodiments of nozzles <NUM> for use in a patient interface. As shown in <FIG>, each nozzle <NUM> may include a gusset portion <NUM> in the conduit <NUM> that interconnects the nozzle portion <NUM> with a cushion. The gusset portion may have any suitable width. For example, <FIG> illustrates a narrower gusset portion <NUM>, whereas <FIG> illustrates a wider gusset portion <NUM>. The gusset portion <NUM> would allow articulation of the nozzle <NUM> as well as provide upward pressure of the nozzle <NUM> into the patient's nasal passage. That is, the gusset portion <NUM> allows the change in sealing force to be in accordance with the change in treatment pressure.

As shown in <FIG>, each nozzle <NUM> may include a dual wall construction. Specifically, the nozzle <NUM> includes a thin membrane <NUM> that surrounds the upper nozzle portion <NUM> to enhance the seal of the nozzle <NUM> with the patient's nasal passage. As illustrated, the upper nozzle portion <NUM> may include one or more openings <NUM> for air communication to improve inflation of the membrane <NUM>. The openings <NUM> may have any suitable shape, e.g., ring-like, and may have any suitable size. Also, as shown in <FIG>, each nozzle <NUM> may include a gusset portion <NUM> in the conduit <NUM> that interconnects the nozzle portion <NUM> with a cushion. Further, both embodiments may include more than one membrane <NUM>, thereby providing a nozzle having a three or more wall construction.

<FIG> illustrate-embodiments of support members for supporting nozzles <NUM> of a patient interface and properly aligning them with the patient's nasal passages. For example, <FIG> illustrate a support member in the form of a C-shaped spring <NUM> having openings <NUM> for receiving nozzle conduits therein. The spring <NUM> is positioned between the side wall <NUM> of the cushion <NUM> and the nozzle portions <NUM> of the nozzles <NUM>, and provides a biasing force to extend the nozzles <NUM> and maintain a substantially rigid configuration to facilitate proper alignment and seal with the patient's nasal passages. The spring <NUM> may be constructed of any suitable material, e.g., metal or polymer. Also, additional adjustment may be added to the spring, e.g., additional bending axis <NUM> that allows lateral adjustment of the nozzles.

<FIG> illustrate a support member in the form of an adjustable slider mechanism <NUM> having a mounting portion <NUM> and a support portion <NUM> with openings <NUM> for receiving nozzle conduits therein. The mounting portion <NUM> is secured to the frame <NUM> of the patient interface, e.g., by a fastener, and the support portion <NUM> is engaged with the nozzle portions <NUM> to extend the nozzles <NUM> and maintain a substantially rigid configuration to facilitate proper alignment and seal with the patient's nasal passages. As illustrated, the opening <NUM> in the mounting portion <NUM> for receiving the fastener is elongated, which allows adjustment of the mechanism <NUM> with respect to the nozzles <NUM>. Also, additional adjustment may be added to the mechanism, e.g., additional bending axis <NUM> that allows lateral adjustment of the nozzles and bending axis <NUM> to change the angle of contact between the nozzles and patient.

<FIG> illustrate a support member in the form of a wedge <NUM> having openings <NUM> for receiving nozzle conduits therein. The wedge <NUM> is positioned between the side wall <NUM> of the cushion <NUM> and the nozzle portions <NUM> of the nozzles <NUM>, and extends the nozzles <NUM> and maintains a substantially rigid configuration to facilitate proper alignment and seal with the patient's nasal passages. The wedge <NUM> may have various angles and thicknesses to achieve the optimal alignment and seal of the nozzles <NUM>. Also, additional adjustment may be added to the wedge, e.g., additional bending axis <NUM> that allows lateral adjustment of the nozzles. Further, the wedge <NUM> may be constructed of any suitable material, e.g., foam, rigid plastic, elastomeric material such as silicone.

<FIG> illustrate an embodiment of a patient interface having a cushion <NUM> and a pair of nozzles <NUM> mounted to the cushion <NUM>. As illustrated, the cushion <NUM> is shaped as a boomerang, and may include rims <NUM> extending from the side wall of the cushion <NUM>.

<FIG> illustrate an embodiment of a patient interface wherein the frame <NUM> includes extended portions <NUM> to cover the cheek regions of the patient's face. This arrangement is structured to prevent or at least control cheek blowout. Also, as illustrated, the frame <NUM> is structured such that inlet conduits <NUM> are coupled to opposing sides of the frame <NUM> for delivering breathable gas into the patient interface. However, one or more inlet conduits <NUM> may be coupled to the frame <NUM> in any other suitable manner, e.g., to the front of the frame.

<FIG> illustrate an embodiment of a patient interface wherein the frame <NUM> includes an inlet conduit <NUM> coupled to one side thereof and an anti-asphyxia valve module <NUM> coupled to the opposite side thereof. It should be understood that the inlet conduit <NUM> and module <NUM> can be interchanged.

As shown in <FIG>, the anti-asphyxia module <NUM> includes an anti-asphyxia valve <NUM> that is housed within an anti-asphyxia cap <NUM> secured to the frame <NUM>. As illustrated, the anti-asphyxia cap <NUM> includes a plurality of openings <NUM>, and the anti-asphyxia valve <NUM> includes a flexible membrane <NUM> that is movable between operative and inoperative positions. In the inoperative position (shown in solid line in <FIG>), the membrane <NUM> is spaced from the cap <NUM> so that atmospheric air can pass through the openings <NUM>. The membrane <NUM> is moved into the operative position (shown in dotted lines in <FIG>) by mask pressure and closes the openings <NUM> so that atmospheric air cannot pass through the openings <NUM>. Embodiments of such anti-asphyxia valve and anti-asphyxia cap are disclosed in <CIT>.

The anti-asphyxia valve module <NUM> has the advantage of being in close proximity to the patient's mouth. The close proximity to the mouth improves CO<NUM> washout, is good for the stability of the system (i.e., there is not a heavy weight located at a distance from the patient interface), and is fail safe if the anti-asphyxia valve module <NUM> is not attached to the device. As illustrated, the frame and/or cushion may include an exhaust vent <NUM>. Also, headgear <NUM> is attached to frame <NUM> in any suitable manner to maintain the cushion and nozzles in a desired adjusted position on the patient's face. In the illustrated embodiment, the headgear <NUM> includes a strap that extends below the ears and around the upper portion of the patient's neck, and a strap that extends in front of the ears and over the top of the patient's head. However, the headgear <NUM> may include any other suitable strap arrangement.

<FIG> illustrate an embodiment of a headgear assembly <NUM> removably coupled to the frame <NUM> of a patient interface so as to maintain the cushion and nozzles in a desired adjusted position on the patient's face. As illustrated, the headgear assembly <NUM> includes two straps each having an independent attachment to the frame <NUM>. Specifically, the headgear assembly <NUM> includes an upper strap <NUM>, a lower strap <NUM>, and a connecting strap <NUM> that interconnects the upper and lower straps <NUM>, <NUM>. Each end of the upper and lower straps <NUM>, <NUM> includes an attachment member <NUM> adjustably secured thereto. Each attachment member <NUM> is interlockable with a respective anchor 165a, 165b provided on the frame <NUM> as discussed in greater detail below.

As best shown in <FIG>, each attachment member <NUM> includes a crossbar <NUM> that enables respective end portions of the straps to be wrapped around, in a known manner. The free ends of the straps include a strip of hook material <NUM> attached thereto by stitching, for example, that engages the loop material of the remainder of the strap to secure the attachment member in place. The hook/loop arrangement, e.g., Velcro®, allows adjustment of the straps with respect to the attachment member <NUM>. Each attachment member <NUM> is in the form of a female connector that includes a relatively large lead-in opening 168a that leads into a relatively smaller attachment opening 168b.

The frame includes a main body and side frame member provided on each lateral side of the main body. The main body includes an aperture that is coupled to an inlet conduit (<NUM>) for delivering breathable gas. Upper and lower anchors 165a, 165b on each side thereof. As best shown in <FIG>, each anchor is in the form of a male connector, e.g., protruding knob. In use, each attachment member <NUM> is interlocked with a respective anchor 165a, 165b by first moving the attachment member <NUM> adjacent the respective anchor 165a, 165b such that the respective anchor 165a, 165b extends through the larger opening 168a, and then the attachment member <NUM> is moved to interlock the respective anchor 165a, 165b with the smaller opening 168b. As shown in <FIG>, the attachment members <NUM> on the ends of the lower strap <NUM> are adapted to releasably interlock with respective lower anchors 165b on the frame <NUM>, and the attachment members <NUM> on the ends of the upper strap <NUM> are adapted to releasably interlock with respective upper anchors 165a on the frame <NUM>. As shown in <FIG>, a soft flexible finger tab <NUM> is provided on the end of each attachment member <NUM> to facilitate engagement and disengagement of the attachment member <NUM> to the frame <NUM>. As illustrated, the free end of the finger tab <NUM> may include a ball-like shape.

When mounted, each attachment member <NUM> is substantially flush with the frame <NUM>. As a result, this arrangement provides no protrusions that can lead to inadvertent disengagement of the straps. Also, there are no obstructions to the patient, e.g., when sleeping on his/her side.

Also, the arrangement enables intuitive and dexterous attachment movement, permits quick release of the patient interface, and the attachment member <NUM> may be freely rotated with respect to the anchor 165a, 165b to allow the patient interface to self-align on the patient's face.

When mounted on a patient, the upper and lower straps <NUM>, <NUM> follow two vectors to effect mask stability. Specifically, the lower strap <NUM> extends below the ears and around the upper portion of the patient's neck and the upper strap <NUM> extends over the ears and around a top portion of the patient's head. The connecting strap <NUM> extends along the rear portion of the patient's head, which holds the lower strap <NUM> in place during head rotation. One or more of the straps may be flared, e.g., at the rear, in order to better conform with the contours of the patient's head which helps reduce head pressure from strap tension.

The above arrangement enables the patient interface to be balanced, e.g., by tuning the patient interface so that sufficient pressure is applied to regions of the cushion and nozzles so an adequate seal is attained. Also, the above arrangement positions the straps away from patient's face.

<FIG> illustrate another embodiment of a headgear assembly <NUM> removably coupled to the frame <NUM> of a patient interface. As illustrated, the headgear assembly <NUM> includes two straps each having an independent attachment to the frame <NUM>. Specifically, the headgear assembly <NUM> includes an upper strap <NUM> and a lower strap <NUM>. Each end of the upper strap <NUM> includes an upper locking clip 173a secured thereto and each end of the lower strap includes a lower locking clip 173b secured thereto. Each locking clip 173a, 173b is interlockable with a respective clip receiver 174a, 174b provided on the frame <NUM> as discussed in greater detail below.

As illustrated, each upper clip 173a includes a crossbar <NUM> that enables respective end portions of the upper straps <NUM> to be wrapped around, in a known manner. In the illustrated embodiment, each free end of the upper strap <NUM> is secured to the remainder of the strap, e.g., by stitching, to secure the clip in place. Also, an intermediate portion of the upper strap <NUM> includes an adjustable ladder lock arrangement <NUM> for adjustment purposes. Each lower clip 173b includes an adjustable ladder lock arrangement <NUM> that enables respective end portions of the lower strap <NUM> to be engaged, in a known manner. Each free end of the lower strap <NUM> is held in place to the remainder of the strap by a watch strap style retainer <NUM>. However, the straps may be secured to the clips 173a, 173b in any other suitable manner, e.g., Velcro®. Further, each clip 173a, 173b includes a side wall having a longitudinally extending slot <NUM> that leads into a transversely extending slot <NUM>.

The frame <NUM> includes upper and lower clip receivers 174a, 174b on each side thereof. As best shown in <FIG>, each clip receiver 174a, 174b includes a resiliently flexible tab <NUM> having a ramped surface leading to a locking shoulder <NUM> and a release projection. In use, each clip 173a, 173b is interlocked with a respective clip receiver 174a, 174b by first moving the clip receiver 174a, 174b into the respective clip 173a, 173b such that the release projection <NUM> extends through the longitudinally extending slot <NUM> until the locking shoulder <NUM> interlocks with the transversely extending slot <NUM> with a snap fit. The clip 173a, 173b may be released from the respective clip receiver 174a, 174b by depressing the release projection <NUM> until the locking shoulder <NUM> releases from the transversely extending slot <NUM>. As shown in <FIG>, the lower clips 173b on the ends of the lower strap <NUM> are adapted to releasably interlock with respective lower clip receivers 174b on the frame <NUM>, and the upper clips 173a on the ends of the upper strap <NUM> are adapted to releasably interlock with respective upper clip receivers 174a on the frame <NUM>. The clip arrangement may provide audible feedback when the clip 173a, 173b is attached to the respective clip receiver 174a, 174b.

Also, as shown in <FIG>, each clip 173a, 173b maybe rotatably engaged with the respective strap such that the clip <NUM>, 173b may be freely rotated with respect to the strap to allow the patient interface to self-align on the patient's face.

Similar to the above-described headgear arrangement, the lower strap <NUM> extends below the ears and around the upper portion of the patient's neck and the upper strap <NUM> extends over the ears and around a top portion of the patient's head.

<FIG> illustrate another embodiment of a headgear assembly <NUM> removably coupled to the frame <NUM> of a patient interface. As illustrated, the headgear assembly <NUM> includes two straps with a single point of attachment to the frame <NUM>. Specifically, the headgear assembly <NUM> includes an upper strap <NUM> and a lower strap <NUM>. One end of the upper and lower straps <NUM>, <NUM> is adjustably secured to one attachment member <NUM>, and the other end of the upper and lower straps <NUM>, <NUM> is adjustably secured to another attachment member <NUM>. Each attachment member <NUM> is interlockable with a respective anchor <NUM> provided on the frame <NUM> as discussed in greater detail below.

As best shown in <FIG>, each attachment member <NUM> is generally V-shaped and includes a upper and lower crossbars 195a, 195b that enable respective end portions of the straps <NUM>, <NUM> to be wrapped around, in a known manner. The free ends of the straps <NUM>, <NUM> include a strip of hook material attached thereto by stitching, for example, that engages the loop material of the remainder of the strap to secure the attachment member in place. The hook/loop arrangement, e.g., Velcro®, allows adjustment of the straps <NUM>, <NUM> with respect to the attachment member <NUM>. However, the straps <NUM>, <NUM> may be secured to the attachment member <NUM> in any other suitable manner, e.g., adjustable ladder-lock arrangement. Each attachment member <NUM> includes a relatively large lead-in into a relatively smaller attachment opening <NUM>.

The frame includes an anchor <NUM> on each side thereof. As best shown in <FIG>, each anchor <NUM> is in the form of a protruding knob. Moreover, each anchor <NUM> is mounted on a sliding adjustment mechanism that allows sliding adjustment of the anchor <NUM> between upper and lower portions of the frame <NUM>. Specifically, the anchor <NUM> is mounted on a slide <NUM> that is movable by a button <NUM> by sliding the button <NUM> within a slot to adjust the anchor height. The adjustment mechanism may be held in position by, e.g., frictional engagement, detents that would allow for discrete steps of movement.

In use, each attachment member <NUM> is interlocked with a respective anchor <NUM> by first moving the attachment member <NUM> adjacent the respective anchor <NUM> such that the anchor <NUM> extends through the lead-in, and then the attachment member <NUM> is moved to interlock the anchor <NUM> with the smaller attachment opening <NUM>. As shown in <FIG>, a spring mechanism <NUM> may be incorporated into the opening <NUM> so that the connection does not wear. As shown in <FIG>, each end of the frame <NUM> interlocks with a respective attachment member <NUM>, and each attachment member <NUM> secures ends of the respective upper and lower straps <NUM>, <NUM>. As illustrated, a soft flexible finger tab <NUM> is provided on the end of each attachment member <NUM> to facilitate engagement and disengagement of the attachment member <NUM> to the frame <NUM>. As illustrated, the free end of the finger tab <NUM> may include one or more protrusions for finger grip. Also, the headgear straps <NUM>, <NUM> are preferably elastic to help with fitting.

The arrangement enables intuitive and dexterous attachment movement, permits quick release of the patient interface, and the attachment member <NUM> may be freely rotated with respect to the anchor <NUM> to allow the patient interface to self-align on the patient's face.

Similar to the above-described headgear arrangements, the lower strap <NUM> extends below the ears and around the upper portion of the patient's neck and the upper strap <NUM> extends over the ears and around a top portion of the patient's head.

<FIG> illustrate another embodiment of a headgear assembly <NUM> removably coupled to the frame <NUM> of a patient interface. As illustrated, the headgear assembly <NUM> includes two straps with a single point of attachment to the frame <NUM>. Specifically, the headgear assembly <NUM> includes an upper strap <NUM> and a lower chin strap <NUM>. One end of the upper and lower straps <NUM>, <NUM> is adjustably secured to one attachment member <NUM>, and the other end of the upper and lower straps <NUM>, <NUM> is adjustably secured to another attachment member <NUM>. Each attachment member <NUM> is interlockable with a respective anchor <NUM> provided on the frame <NUM> as discussed in greater detail below.

As best shown in <FIG>, each attachment member <NUM> includes an upper clip receiver <NUM> and a lower crossbar <NUM> As illustrated, end portions of the upper strap <NUM> are secured to respective locking clips <NUM> (e.g., strap wrapped around clip cross-bar and free end of the strap is secured to the remainder of the strap by Velcro® arrangement), which are releasably interlocked with a respective upper clip receiver <NUM>. The interlocking engagement may be similar to the snap-fit clip arrangement disclosed in <FIG>. Respective end portions of the lower strap <NUM> are wrapped around a respective lower cross-bar <NUM>, in a known manner. The free ends of the lower straps <NUM> may engage the remainder of the strap via a Velcro® arrangement Each attachment member <NUM> also includes a relatively large lead-in into a relatively smaller attachment opening <NUM>.

The frame <NUM> includes an anchor <NUM>, e.g., in the form of a protruding knob, on each side thereof. The anchors <NUM> may be mounted on a sliding adjustment mechanism similar to that shown in <FIG>. In use, each attachment member <NUM> is interlocked with a respective anchor <NUM> by first moving the attachment member <NUM> adjacent the respective anchor <NUM> such that the anchor <NUM> extends through the lead-in, and then the attachment member <NUM> is moved to interlock the anchor <NUM> with the smaller attachment opening <NUM>. As shown in <FIG>, a spring mechanism <NUM> may be incorporated into the opening <NUM> so that the connection does not wear. As shown in <FIG>, each end of the frame <NUM> interlocks with a respective attachment member <NUM>, and each attachment member <NUM> secures ends of the respective upper and lower straps <NUM>, <NUM>. As illustrated, a soft flexible finger loop <NUM> is provided on the side of each attachment member <NUM> to provide a means for quick disengagement of the attachment member <NUM> from the frame <NUM>. Also, the headgear straps <NUM>, <NUM> are preferably elastic to help with fitting.

When mounted on a patient, the lower strap <NUM> extends downwardly and around the patient's chin and the upper strap <NUM> extends over the ears and around a top portion of the patient's head.

<FIG> illustrate another embodiment of a headgear assembly <NUM> removably coupled to the frame <NUM> of a patient interface. As shown in <FIG>, the headgear assembly <NUM> includes an upper strap <NUM> and a lower strap <NUM>. However, the lower strap <NUM> is optional. Also, the strap may have two-strap configuration wherein upper and lower straps <NUM>, <NUM> are incorporated into a single structure as shown in <FIG>. Each end of the straps includes an attachment member <NUM> adjustably secured thereto. Each attachment member <NUM> is interlockable with a respective anchor 238a, 238b provided on the frame <NUM> as discussed in greater detail below.

Each attachment member <NUM> may be secured to a respective end of the strap in any suitable manner, e.g., stitching, Velcro®. Also, each attachment member <NUM> includes an attachment opening.

The frame <NUM> includes upper and lower anchors 238a, 238b on each side thereof. Each anchor 238a, 238b is in the form of a protruding knob. In use, each attachment member <NUM> is interlocked with a respective anchor 238a, 238b by moving the attachment member <NUM> adjacent the respective anchor 238a, 238b such that the respective anchor 238a, 238b extends through the attachment opening.

As shown in <FIG>, the upper anchor 238a is mounted on a rotatable plate <NUM> that allows the position of the upper anchor 238a to be rotatably adjusted. This arrangement allows the angle of the patient interface with respect to the patient's face to be adjusted. Moreover, the arrangement allows the headgear assembly <NUM> to remain in the same position relative to the patient's head even as the angle of the patient interface changes. Rotation may be discrete with specific indexed positions, or rotation may be continuous with the desired position being maintained by friction.

A soft flexible finger tab <NUM> is provided on the end of each attachment member <NUM> to facilitate engagement and disengagement of the attachment member <NUM> to the frame <NUM>. As illustrated, the free end of the finger tab <NUM> may include one or more gripping protrusions.

Also, all the headgear assemblies described above may incorporate rigidizing elements (via insertion of rigid panels, stitiching, lamination, or other means) to add rigidity to the headgear assemblies to aid in mask stability.

It should be understood that the cushion <NUM> and nozzles <NUM> described above may be formed from any suitable material. For example, the cushion <NUM> and nozzles <NUM> may be formed from a gel-like material, or they may be formed from a foam-like material. Also, the cushion <NUM> and nozzles <NUM> may be formed separately from one another, or may be integrally formed as a one-piece structure.

Further, although the above embodiments are described in relation to nozzles, nasal prongs (which are inserted into the nose) and/or nasal dilators are also contemplated.

Advantages of illustrated preferred embodiments may include:.

The reduction in the area of the face across which a seal must be formed allows a single size or shape to fit a wider range of patient geometry. This is particularly advantageous for a clinician since the patient interface is both easier to fit to a new patient and potentially more forgiving of fitting errors. The independent nature of the chambers due to the flexible connection, also allows for some movement of the face during the night without loss of seal. This leads to far more stability than conventional single chamber full face masks.

The provision of flexibility allows the seal to remain throughout jaw and head position movement as well as providing adjustment for the different geometry of a wide range of patients. The task of fitting varying patient geometry is made easier by the removal of the need to seal around the complex form of the nasal bridge which is found in most of the prior art masks that seal both the nasal and oral passages. The lack of seal around the nasal bridge also allows the patient to wear spectacles.

Claim 1:
A patient interface for delivery of a flow of pressurized breathable gas to a patient for treatment of sleep disordered breathing, the patient interface comprising:
a nasal seal configured to fluidly communicate the flow of pressurized breathable gas with nasal airways of the patient when the nasal seal is applied to the patient's nose without forming a seal on a nasal bridge region of the patient's face; and
an oral seal (<NUM>) configured to sealingly engage around an exterior of the patient's mouth when applied to the patient's face, and wherein the nasal seal and the oral seal form a single breathing chamber, and
wherein the oral seal (<NUM>) includes a side wall (<NUM>), a pair of rims (<NUM>) extending away from the side wall (<NUM>), and a membrane (<NUM>) provided to substantially surround the rim (<NUM>),
wherein the membrane (<NUM>) is thinner than the rim (<NUM>),
wherein the membrane (<NUM>) is adapted to form a seal around the lips of a patient, and
wherein the rims (<NUM>) are adapted to add rigidity to the membrane (<NUM>) in regions of the patient's cheeks.