Patent Description:
The present invention generally relates to masks for use in communicating a flow of breathing gas to an airway of a patient.

There are numerous situations where it is necessary or desirable to deliver a flow of breathing gas non-invasively to the airway of a patient, i.e., without intubating the patient or surgically inserting a tracheal tube in their esophagus. For example, it is known to ventilate a patient using a technique known as non-invasive ventilation (NIV). It is also known to deliver continuous positive airway pressure (CPAP) or variable airway pressure, which varies with the patient's respiratory cycle, to treat a medical disorder, such as sleep apnea syndrome, in particular, obstructive sleep apnea (OSA), chronic obstructive pulmonary disease (COPD), or congestive heart failure (CHF).

Non-invasive ventilation and pressure support therapies involve the placement of a patient interface device, which is typically a nasal or nasal/oral mask, on the face of a patient to interface the ventilator or pressure support system with the airway of the patient so that a flow of breathing gas can be delivered from the pressure/flow generating device to the airway of the patient.

Typically, patient interface devices include a mask shell or frame having a cushion attached to the shell that contacts the surface of the patient. The mask shell and cushion are held in place by a headgear that wraps around the head of the patient. The mask and headgear form the patient interface assembly. A typical headgear includes flexible, adjustable straps that extend from the mask to attach the mask to the patient.

<CIT> discloses an interface assembly including an interface, such as a mask, that is secured to a head using a headgear assembly. The headgear assembly can include at least one halo portion and a plurality of straps. The headgear assembly can include both a front halo portion and a rear halo portion. In some arrangements, the headgear and mask define an adjustable closed loop. In some arrangements, the headgear can include one or more rigid portions that contact the user's face to at least partially isolate a seal of the mask from tightening forces applied to the headgear. In some arrangements, the mask is an oral-nasal mask and the headgear applies a force to the mask comprising an upward force component. In some arrangements, the headgear can be contoured to the user's head.

<CIT> provides a nasal cushion for a mask assembly for delivering pressurised gas to the nose of a subject for treatment with continuous positive air pressure. The nasal cushion includes a self-supporting side wall defining a nose-receiving cavity; the side wall extending from a first end to a second end. The side wall is formed continuously with a thin membrane extending inwardly from a second end of the side wall into the nose-receiving cavity for sealingly engaging the nose, upper lip and cheeks of a subject. The side wall has continuously varying thickness. The first end of the side wall is adapted to engage a mask frame. The invention further provides a mask assembly for delivering pressurised gas to a patient, the assembly including a nasal cushion for sealing against the nose, cheek and-lip area the nasal cushion as described, a frame for receiving the nasal cushion, and a headgear, the headgear including a rigid arm for positioning behind the ear of a patient.

<CIT> discloses a patient interface device that includes a mask and a headgear component for attaching the patient interface device to the head of a patient. The headgear component includes a strap and an attachment element provided between the mask and the strap. The attachment element has a mask attachment portion coupled to the mask, a strap attachment portion coupled to the strap, and a flexible linkage portion provided between the mask attachment portion and the strap attachment portion. The flexible linkage portion is more flexible than both the mask attachment portion and the strap attachment portion to enable the mask attachment element to flex, bend, and/or twist along multiple axes to conform to particular facial contours of the patient.

<CIT> discloses a patient interface device that includes a mask with a shell having a recess defined therein, thereon, or by a material coupled thereto and a headgear component for attaching the patient interface device to the head of a patient. The headgear component includes a strap and an attachment element provided between the mask and the strap, wherein the attachment element has a strap attachment portion coupled to the strap and a mask attachment portion disposed in the recess in a manner that selectively couples the headgear component to the mask.

Because such masks are typically worn for an extended period of time, a variety of concerns must be taken into consideration. For example, in providing CPAP to treat OSA, the patient normally wears the patient interface device all night long while he or she sleeps. One concern in such a situation is that the patient interface device is as comfortable as possible, otherwise the patient may avoid wearing the interface device, defeating the purpose of the prescribed pressure support therapy. It is also important that the interface device be simple to put on and taken off by a patient so that a patient would be more likely to utilize the device as prescribed.

As one aspect of the invention a mask structured to be coupled to a head of a patient with a headgear for use in communicating a flow of breathing gas to an airway of a patient is provided. The mask comprises a patient interface including: a faceplate, and a cushion having a first end coupled to the faceplate and an opposite second end that is structured to sealingly engage a portion of a face of the patient about one or more airways of the patient. The mask also comprises a frame including: a first arm member having a first end coupled to the patient interface via a first coupling arrangement and an opposite second end structured to be coupled to the headgear, and a second arm member having a first end selectively coupled to the patient interface via a second coupling arrangement and an opposite second end structured to be coupled to the headgear, wherein the second coupling arrangement requires a lesser uncoupling force to uncouple than the first coupling arrangement.

The first frame member may be coupled to the faceplate of the patient interface, and the first end of the second frame member may be coupled to the faceplate of the patient interface.

The first coupling arrangement may provide for the first end of the first arm member to be selectively coupled to the faceplate.

The first end of the cushion and the faceplate may be coupled via over molding.

The first coupling arrangement may comprise: a post member extending outward from the faceplate along a central axis; and an aperture defined in the first end of the first arm member correspondingly shaped to receive the post member.

The post member may include a first feature that interacts with a corresponding second feature of the aperture to constrain the post member within the aperture.

The first feature may comprise a flared region and the second feature is a may be a recessed portion defined in the aperture.

When viewed along the central axis, the post member may have an elongated cross-section.

The second coupling arrangement may comprise: a ridge extending from the first end of the second arm member; and a groove defined in the faceplate that is structured to receive the ridge therein.

The groove may include a plurality of segments comprising: a first segment, a second segment extending generally parallel to the first segment, and a third segment extending between, and generally perpendicular to, the first segment and the second segment, wherein the ridge includes a plurality of segments comprising: a first segment, a second segment extending generally parallel to the first segment of the ridge, and a third segment extending between, and generally perpendicular to, the first segment of the ridge and the second segment of the ridge, and wherein the first, second and third segments of the ridge are sized and positioned to correspondingly engage the first, second and third segments of the groove.

The ridge may comprise a mechanical hook that engages a portion of the groove.

The mechanical hook may comprise an inward angled surface which engages a cooperative angled surface of the groove when the ridge is disposed in the groove.

The mechanical hook may comprise an inward extending protrusion disposed adjacent, and defined in-part by, an outward extending recess that hooks around a protrusion extending into the groove.

The second coupling arrangement may further comprise a first magnetic element positioned in the faceplate and a second magnetic element correspondingly positioned in the second arm member such that the first magnetic element and the second magnetic element are positioned adjacent to each other and attracted toward each other which the ridge is disposed in the groove.

It is to be expressly understood, however, that the drawings are provided for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.

As used herein, the singular form of "a", "an", and "the" include plural references unless the context clearly dictates otherwise. As used herein, the statement that two or more parts or components are "coupled" shall mean that the parts are joined or operate together either directly or indirectly, i.e., through one or more intermediate parts or components, so long as a link occurs. As used herein, "directly coupled" means that two elements are directly in contact with each other. As used herein, "fixedly coupled" or "fixed" means that two components are coupled so as to move as one while maintaining a constant orientation relative to each other. As used herein, "selectively coupled" means that two elements are coupled in a manner that can be uncoupled and coupled again without requiring any special tool or tools and without causing damage to either of the elements. As used herein, "permanently coupled" means that two elements are coupled in a manner that cannot be uncoupled without causing damage to one or both of the elements and/or modifying the arrangement in a manner such that the elements cannot be recoupled in the original manner without the use of further materials. For example, elements that are glued, welded, or otherwise bonded would be example of elements that are "permanently coupled".

As used herein, the word "unitary" means a component is created as a single piece or unit. That is, a component that includes pieces that are created separately and then coupled together as a unit is not a "unitary" component or body. As employed herein, the statement that two or more parts or components "engage" one another shall mean that the parts exert a force against one another either directly or through one or more intermediate parts or components. As employed herein, the term "number" shall mean one or an integer greater than one (i.e., a plurality) and the singular form of "a", "an", and "the" include plural referents unless the context clearly indicates otherwise.

A system <NUM> adapted to provide a regimen of respiratory therapy to a patient is generally shown in <FIG> positioned on the head of a patient (not numbered). System <NUM> includes a pressure generating device <NUM> (shown schematically); a mask <NUM> shown disposed on, and secured to, the head of a patient (not numbered) with a headgear <NUM>; and a patient circuit <NUM> (partially shown schematically) coupled between pressure generating device <NUM> and mask <NUM>. Pressure generating device <NUM> is structured to generate a flow of breathing gas and may include, without limitation, ventilators, constant pressure support devices (such as a continuous positive airway pressure device, or CPAP device), variable pressure devices (e.g., BIPAP®, Bi-Flex®, or C-Flex™ devices manufactured and distributed by Philips Respironics of Murrysville, Pennsylvania), and auto-titration pressure support devices. Headgear <NUM> may be of any suitable arrangement and/or material as the example headgear <NUM> shown in the FIGS. It is thus to be appreciated that headgear <NUM> is provided in the FIGS. solely for exemplary purposes only to show one example of how mask <NUM> may be secured to the head of a patient therewith.

Patient circuit <NUM> is structured to communicate the flow of breathing gas from pressure generating device <NUM> to mask <NUM> which then communicates the flow of breathing gas to an airway of the patient. Typically, patient circuit <NUM> includes a conduit or tube which couples pressure generating device <NUM> and mask <NUM>. In the example embodiment illustrated in <FIG>, patient circuit <NUM> includes a flexible conduit <NUM> (shown partially schematically) and an elbow <NUM> coupled to mask <NUM>.

Continuing to refer to <FIG>, and additionally <FIG>, mask <NUM> includes a patient interface <NUM> and a frame <NUM> coupled thereto that is structured to secure patient interface <NUM> to the head of the patient via headgear <NUM>, which is also coupled to frame <NUM> as discussed further below. Patient interface <NUM> includes a faceplate <NUM>, to which patient circuit <NUM> is coupled, and a cushion <NUM>. In the example embodiment illustrated in <FIG>, faceplate <NUM> is formed from a rigid or semi-rigid material (e.g., without limitation, silicone, plastic), however it is to be appreciated that other suitable materials may be used without varying from the scope of the present invention. Cushion <NUM> on the other hand is formed from a soft conformable material (e.g., without limitation, silicone) and includes a first end <NUM> that is coupled to faceplate <NUM> generally at or about a peripheral edge (not numbered of faceplate <NUM>.

Cushion <NUM> further includes a second end <NUM>, disposed opposite first end <NUM>, that is structured to sealingly engage a portion of the face of a user about one or more airways of the user. Cushion <NUM> may be selectably coupled to faceplate <NUM> or may be generally permanently coupled (e.g., via over molding). In the example embodiment shown in <FIG>, cushion <NUM> engages the face of a user about the nose and thus both nostrils of the user, however, it is to be appreciated that embodiments of the present invention may be employed with other cushion arrangements (e.g., without limitation, nasal pillows, oral/nasal mask) without varying from the scope of the present invention. Together faceplate <NUM> and cushion <NUM> define a user cavity (not numbered) that is structured to receive the flow of gas produced by pressure generating device <NUM> and communicated thereto by patient circuit <NUM>.

As mentioned above, mask <NUM> includes frame <NUM> that is coupled to patient interface <NUM> and to headgear <NUM> for securing patient interface <NUM> to the head of the patient. More particularly, frame <NUM> is formed from a semi-rigid or other suitable material (e.g., without limitations, plastic, fabric covered plastic, silicone reinforced with plastic, etc.) and includes a first arm member <NUM> coupled to, and extending outward in a first direction from patient interface <NUM> and a separate second arm member <NUM> coupled to, and extending outward from patient interface <NUM> in a second direction generally opposite the first direction. In order to provide for patient interface <NUM> to be readily disposed/secured on - and subsequently be unsecured/removed from - the head of the patient, at least one of arm members <NUM> or <NUM> is/are selectively coupled to patient interface. If both arm members <NUM> and <NUM> are selectively coupled to patient interface <NUM> (which desirably allows for patient interface to be swapped out from frame <NUM> and headgear <NUM> for cleaning or replacement ), one of arm members <NUM> or <NUM> is selectively coupled to patient interface <NUM> in a manner that requires a lesser force to uncouple (i.e., a lesser uncoupling force) than the other arm member <NUM> or <NUM> from patient interface <NUM>.

By having only one arm member <NUM> or <NUM> selectively coupled, or one arm member <NUM> or <NUM> selectively coupled with a lesser uncoupling force, the one arm member <NUM> or <NUM> may be uncoupled from patient interface <NUM> to provide for mask <NUM> to be removed from the patient or installed on the patient while the patient interface <NUM> is still coupled/secured with frame <NUM> and headgear <NUM> by the other arm member <NUM> or <NUM>. If both arm members <NUM> and <NUM> were uncoupleable with generally the same force, patient interface <NUM> would tend to undesirably completely uncouple from frame <NUM> and headgear <NUM> and fall from the patient (typically to the floor adjacent the patient's bed).

As discussed immediately below, in the one example embodiment shown in <FIG>, each of arm members <NUM> and <NUM> are selectively coupled to faceplate <NUM> of patient interface <NUM>, with second arm member <NUM> being selectively coupled via an arrangement that provides for second arm member <NUM> to be uncoupled from faceplate <NUM>, and thus patient interface <NUM>, more easily (i.e., with a lesser force) than first arm member <NUM>. It is to be appreciated, that one or more of the coupling locations (i.e., on one or both of faceplate <NUM> and/or cushion <NUM>) and/or coupled arrangements described in conjunction with such embodiment may be varied without varying from the scope of the present invention. It is also to be appreciated that the one of arm member <NUM> or <NUM> that is more easily/readily uncoupled from patient interface <NUM> may be varied without varying from the scope of the present invention.

Continuing to refer to <FIG>, and additionally <FIG>, the coupling between each of arm members <NUM> and <NUM> of frame <NUM> and patient interface <NUM> will now be described in detail. As shown in <FIG>, first arm member <NUM> of frame <NUM> includes a first end 40A that is structured to be coupled to patient interface <NUM> via a first coupling arrangement <NUM> and at least one second end 40B (also 40C in the one example shown) disposed opposite first end 40A that is structured to be coupled (preferably via an adjustable arrangement) to headgear <NUM>. Similarly, second arm member <NUM> of frame <NUM> includes a first end 42A that is structured to be coupled to patient interface <NUM> via a second coupling arrangement <NUM> and at least one second end 42B (also 42C in the one example shown) disposed opposite first end 42A that is structured to be coupled (preferably via an adjustable arrangement) to headgear <NUM>. Although each of the example arm members <NUM> and <NUM> shown in <FIG> includes two opposite ends 40B, 40C and 42B and 42C, it is to be appreciated that the number of opposite ends may vary (e.g., <NUM>, <NUM>, etc.) without varying from the scope of the present invention.

Referring now to <FIG>, first coupling arrangement <NUM> includes a post member <NUM> that is coupled to, or formed as a portion of, faceplate <NUM> and extends outward therefrom along a central axis <NUM> and is structured to interact with a correspondingly shaped aperture <NUM> defined in first end 40A of first arm member <NUM> of frame <NUM>. Post member <NUM> may be formed from thermoplastic or other suitable material or materials and depending on the materials used may formed as a hollow member (such as shown) or as a solid member. Post member <NUM> includes a first feature <NUM> that interacts with a corresponding second feature <NUM> of aperture <NUM> to constrain/couple (either selectively or permanently) post member <NUM> within aperture <NUM>. In the one example shown, first feature <NUM> is a flared region that interacts with second feature <NUM> formed as a recessed portion of aperture <NUM>, however, it is to be appreciated that other features <NUM>, <NUM> may be utilized without varying from the scope of the present invention.

In the example shown in the figures, post member <NUM> (and correspondingly aperture <NUM>) has an elongated cross-section when viewed along axis <NUM> such that when post member <NUM> is positioned in aperture <NUM> of first arm member <NUM> rotation of first arm member <NUM> with respect to faceplate <NUM> (and thus patient interface <NUM>) is limited/prevented to a degree or less. As an alternate embodiment to the arrangement shown in the figures, the elements of first coupling arrangement <NUM> may be reversed (i.e., post <NUM> on first arm member <NUM> and aperture <NUM> defined in faceplate <NUM>) without varying from the scope of the present invention.

Continuing to refer to <FIG>, second coupling arrangement <NUM> includes a groove <NUM> defined in faceplate <NUM> that is structured to receive a ridge <NUM> extending from first end 42A of second arm member <NUM>. As shown in <FIG>, in the illustrated example groove <NUM> includes a plurality of segments including: a first segment 60A, a second segment 60B extending generally parallel to first segment 60A, and a third segment 60C extending between, and generally perpendicular to, first and second segments 60A and 60B. Similarly, ridge <NUM> includes a plurality of corresponding segments including: a first segment 62A, a second segment 62B extending generally parallel to first segment 62A, and a third segment 62C extending between, and generally perpendicular to, first and second segments 62A and 62B. Similar to the function of the elongated cross-sections of first coupling arrangement <NUM> previously discussed, each of first and second segments 60A, 60B and 62A, 62B of first coupling arrangement <NUM> serve to limit/prevent rotation of second arm member <NUM> with respect to faceplate <NUM> (and thus patient interface <NUM>) to a degree or less.

In place of, or in addition to, having multiple segments 60A-60C and 62A-62C, second coupling arrangement <NUM> may include a mechanical hook or interlock arrangement (not numbered), which in the example shown in <FIG> is an inward angled surface <NUM> provided on ridge <NUM> that engages a cooperative angled surface <NUM> of groove <NUM>. Angled surface <NUM> is disposed at an angle θ less than <NUM>° from a pull vector T that would be exerted on second arm member by tightening of headgear <NUM>. It is thus to be appreciated that angled surface <NUM> functions generally as a hook when second arm member <NUM> is tensioned in the direction T (<FIG>) by tightening of headgear <NUM>.

An example of an alternative mechanical hook or interlock arrangement is shown in <FIG>, which is a similar view as that shown in <FIG> and in which similar elements are shown labeled with similar numbering as <FIG> and not described again. In such example embodiment as shown in <FIG>, instead of an inward angled surface <NUM>, ridge <NUM>' includes an inward extending (i.e., generally back toward the majority of second arm member <NUM>') protrusion 70A positioned at a peak (not numbered) of ridge <NUM>' disposed adjacent, and defined in-part by, an outward (i.e., generally away from the majority of second arm member <NUM>') extending recess 70B. Together protrusion 70A and recess 70B function generally as a mechanical hook that hooks around a protrusion <NUM> extending into segment 60C' of groove <NUM>' (i.e., into segment 60C' away from the majority of second arm member <NUM>').

As shown in <FIG> and <FIG>, second coupling arrangement <NUM> further includes a first magnetic element <NUM> positioned in faceplate <NUM> and a second magnetic element <NUM> correspondingly positioned in second arm member <NUM> such that first and second magnetic elements are attracted toward each other. In the example shown in <FIG> and <FIG>, each of magnetic elements <NUM> and <NUM> comprise magnets, however, it is to be appreciated that one of magnetic elements <NUM> and <NUM> may instead be a material to which a magnet would be attracted without varying from the scope of the present invention. As an alternate embodiment to the arrangement shown in the figures, the elements of second coupling arrangement <NUM> may be reversed, i.e., groove <NUM> defined in first arm member <NUM> and ridge <NUM> defined in faceplate <NUM>, without varying from the scope of the present invention. It is to be appreciated that in such alternate version, angled surface <NUM> of ridge <NUM> would be on the opposite side of ridge <NUM> and angled toward a center plane of faceplate <NUM> in order to provide a hook onto which second arm member <NUM> would hook (and resist tensioning of second arm member in the direction T shown in <FIG>).

From the foregoing it is thus to be appreciated that embodiments of the present invention provide improved coupling arrangements for use in securing a patient interface device to the head of a patient that may be readily coupled or uncoupled by a patient.

Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the scope of the appended claims.

The word "comprising" or "including" does not exclude the presence of elements or steps other than those listed in a claim. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. In any device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain elements are recited in mutually different dependent claims does not indicate that these elements cannot be used in combination.

Claim 1:
A mask (<NUM>) structured to be coupled to a head of a patient with a headgear (<NUM>) for use in communicating a flow of breathing gas to an airway of a patient, the mask comprising:
(a) a patient interface (<NUM>) including:
a faceplate (<NUM>), and
a cushion (<NUM>) having a first end coupled to the faceplate and an opposite second end that is structured to sealingly engage a portion of a face of the patient about one or more airways of the patient; and
(b) a frame (<NUM>) including:
a first arm member (<NUM>) having a first end coupled to the patient interface via a first coupling arrangement (<NUM>) and an opposite second end structured to be coupled to the headgear, and
a second arm member (<NUM>) having a first end selectively coupled to the patient interface via a second coupling arrangement (<NUM>) and an opposite second end structured to be coupled to the headgear, characterized in that the second coupling arrangement requires a lesser uncoupling force to uncouple than the first coupling arrangement.