Stabilized mask

A patient interface device includes a cushion defining a cavity therein, the cushion having a first side and an opposite second side. An aperture is formed in the second side and provides access to the cavity, the aperture having a periphery adapted to sealingly engage about the nostrils of a patient when the cushion is disposed on the face of a patient. The patient interface device further includes a pair of stabilizing members coupled to, and extending from, the cushion, each stabilizing member being adapted to contact the face of the patient in the adjacent nasal region below the orbital bone ridge in such a manner that strapping forces, which would otherwise be directed near the nares of the patient, are instead concentrated onto the patient's maxilla.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to nasal masks, and, more particularly, to nasal masks having stabilizing elements.

2. Description of the Related Art

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 the esophagus. For example, it is known to ventilate a patient using a technique known as non-invasive ventilation. It is also known to deliver continuous positive airway pressure (CPAP) or variable airway pressure, such as a bi-level pressure that varies with the patient's respiratory cycle or an auto-titrating pressure that varies with the monitored condition of the patient. Typical pressure support therapies are provided to treat a medical disorder, such as sleep apnea syndrome, in particular, obstructive sleep apnea (OSA), or congestive heart failure.

Non-invasive ventilation and pressure support therapies involve the placement of a patient interface device including a mask component on the face of a patient. The mask component may be, without limitation, a nasal mask that covers the patient's nose, a nasal cushion having nasal prongs that are received within the patient's nares, a nasal/oral mask that covers the nose and mouth, or a full face mask that covers the patient's face. The patient interface device interfaces the ventilator or pressure support device 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. It is known to maintain such devices on the face of a wearer by a headgear assembly having one or more straps adapted to fit over/around the patient's head.

Patients that require pressure support therapy are often confronted with the problem of finding a suitable patient interface device. In finding a suitable patient interface device, such patients frequently struggle with issues relating to the seal and stability of the patient interface device, the comfort of the patient interface device, the size/weight of the patient interface device and the sizing of the patient interface device. These challenges, if not addressed properly, can compromise the patient's compliance with the prescribed therapy.

Nasal masks often appeal to patients as such masks offer attractive advantages to patients due to the fact that they tend to be lighter, provide reduced facial contact, and tend to not restrict the patient's field of vision. Conventional nasal masks typically are one of two primary configurations. Pillows masks are the most commonly adopted configuration and are typically comprised of two channels projecting directly into the separate nasal cavities of the patient. Mounted atop these two channels are soft, compliant, pillows that seal generally in and around the patient's individual nostrils. Additionally, these two channels are conjoined in a central manifold which receives that piped pressure from a pressure delivery system to which the mask is coupled. The arrangement of such pillows generally serves to anchor such masks to a patient's face.

The second common configuration utilizes a cradle cushion. Attached directly to the central manifold, a cut-out is applied which allows both nostrils to receive pressure while simultaneously sealing on the periphery of the nostril openings and upper lip. This configuration has generally not been received in the market place as well as the pillows mask. Without having pillows to anchor the mask, the mask commonly becomes very unstable. One way to resolve this problem is to add support to the headgear to hold the cushion firmly in place, unfortunately there is a negative connotation with hard or bulky material that is used to create this support. Continued focus on reducing the form factor of the cradle cushion has resulted in further reduction in stability of the mask. As stability reduces, air leakage occurs and patients are forced to apply more strapping force, which significantly reduces the comfort of the mask and compliance for patients.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a patient interface device that overcomes the shortcomings of conventional designs. The patient interface device comprises: a cushion defining a cavity therein, the cushion having a first side and an opposite second side; an aperture formed in the second side providing access to the cavity, the aperture having a periphery adapted to sealingly engage about the nostrils of a patient when the cushion is disposed on the face of the patient; and a pair of stabilizing members coupled to, and extending from, the cushion, each stabilizing member being adapted to contact the face of the patient in the adjacent nasal region below the orbital bone ridge in such a manner that strapping forces, which would otherwise be directed near the nares of the patient, are instead concentrated onto the patient's maxilla.

The stabilizing members may be disposed on opposite sides of the aperture. Each of the stabilizing members may be integrally formed with the cushion. Each of the stabilizing members may be bounded by a grooved portion which is structured to allow each stabilizing member to articulate with respect to the cushion. The grooved portion may comprise a baffle. The grooved portion may comprise a locally thinned wall section. The stabilizing members may be formed separately from, and selectively coupled to, the cushion. Each stabilizing member may comprise a cavity formed therein. Each cavity may be in communication with the cavity of the cushion and each cavity may be adapted to be inflated by one or both of the applied system pressure and the exhalation pressure of the patient. Each cavity may be filled with one or more of a low durometer gel or foam. The cushion may comprise a generally cradle shaped elongate hollow body and the first side may be is of a generally convex shape and the opposite second side may be of a generally concave shape. The patient interface device may further comprise a generally rigid elongated front portion coupled to the front side of the cushion, the front portion having a first end, an opposite second end and an aperture disposed therebetween, wherein the aperture is adapted to be coupled to a patient circuit and wherein each of the first end and opposite second end may be adapted to be selectively coupled to a headgear for use in securing the patient interface device to the head of a patient. The front portion may be coupled to the front side of the cushion via a hollow articulating portion. The hollow articulating portion may include an inward curved U-shaped portion disposed along an upper portion thereof.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

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” shall mean that the parts are joined or operate together in a manner such that the components may be separated or uncoupled and then recoupled as desired.

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). As employed herein, the term “and/or” shall mean both alternatives (i.e., “and”) or just one of the alternatives (i.e., “or”).

Embodiments of the present invention provide improved stability to masks used in delivering a flow of a treatments gas to the airway of a patient. Particular exemplary embodiments address constraints in reducing the size of a cradle mask by providing a number of structures which enhance stability and reduce movement of the mask with respect to the face of a patient.

FIGS. 1-8illustrate an exemplary embodiment of a patient interface device10according to the principles of the present invention. Referring toFIG. 1, patient interface device10is shown disposed on the face (not numbered) of a patient and schematically connected to a pressure support system12via a patient circuit14, which communicates gas from pressure support system12to patient interface device10. Patient circuit14is any device, such as flexible tubing, that carries the flow of gas from the pressure/flow generator in pressure support system12to patient interface device10. Pressure support system12is any conventional ventilation or pressure support system. Examples of such pressure support systems include, but are not limited to, a ventilator, a continuous positive airway pressure (CPAP) device, or a variable pressure device, e.g. an auto-titrating device, proportional assist ventilation (PAV®) device, proportional positive airway pressure (PPAP®) device, C-Flex™ device, Bi-Flex™ device, or a BiPAP® device manufactured and distributed by Philips Respironics of Murrysville, Pa., in which the pressure provided to the patient varies with the patient's respiratory cycle so that a higher pressure is delivered during inspiration than during expiration, or other pressure support device.

Patient interface device10includes a cushion16sized and configured to span at least a portion of a patient's face while remaining below the patient's eyes when patient interface device10is disposed on the face of a patient, such as shown inFIGS. 1 and 2. Cushion16comprises a generally cradle shaped elongate hollow body defining a cavity18therein and includes a generally convex shaped front side20and a generally concave shaped rear side22, as shown in the top view ofFIG. 4. An opening24, disposed in rear side22, provides access to cavity18. The periphery (not numbered) of opening24is adapted to sealingly engage about the nostrils of a patient when patient interface device10is disposed on the face of a patient.

Patient interface device10further includes a generally rigid elongated front portion28having a first end30, an opposite second end32and an aperture34disposed therebetween which is adapted to be coupled (either directly or indirectly) to patient circuit14via any suitable coupling mechanism. As perhaps best shown in the front view ofFIG. 2, front portion28is wider than body portion16. A coupling mechanism, such as the snap like coupling mechanisms36illustrated in the FIGS., is provided at or about each of first and second ends30and32for selectively coupling patient interface device10to a headgear (not shown) used in securing patient interface device10to the head of a patient. It is to be appreciated that a variety of coupling mechanisms, slots, or other suitable coupling arrangements may be employed in conjunction with any of a large variety of headgear assemblies for securing patient interface device10to the head of a patient without varying from the scope of the present invention.

Referring to the side and sectional side views ofFIGS. 5 and 6, front portion28is coupled to rear side22of cushion16via a hollow articulating portion40having an inward curved U-shaped portion42(FIG. 6) disposed along an upper portion thereof. It is to be appreciated that such arrangement allows for one or both of cushion16and front portion28to generally be able to move one or more of up, down, and side-to-side with respect to the other of cushion16and front portion28via flexure of articulating portion40. As can be readily appreciated from the sectional view ofFIG. 6, treatment gas received at aperture34from pressure support system12via patient circuit14(as previously discussed) is communicated to cavity18within cushion16via hollow articulating portion40. As shown in the example embodiment illustrated inFIGS. 1-8, patient interface device10may be formed from a single integral elastomeric material (e.g., without limitation, silicone). In example embodiments, materials having a durometer in the range of about 30 Shore A to about 60 Shore A have been utilized. It is to be appreciated, that the present invention also contemplates that patient interface device10may be formed from multiple components formed from the same or different materials which are then coupled together, either permanently or selectively.

In order to help stabilize patient interface device10, and more particularly cushion16on the face of a patient, cushion16further includes a pair of stabilizing members50disposed on generally opposite sides of opening24. As shown inFIGS. 1and2, each stabilizing member50is adapted to contact the face of a patient in the adjacent nasal region generally below the orbital bone ridge in such a manner that strapping forces, which would otherwise be directed near the nares of the patient, are instead concentrated onto the patient's maxilla.FIGS. 14A-14C, respectively, show non-limiting examples of different regions or areas of contact A, B, C that embodiments of stabilizing members50may make on a patient's face. Region A (FIG. 14A) is an example of a support area which generally provides high stability from hose torque/weight in all directions. Regions B and C are examples of support areas of lesser size than region A (and therefore generally reduce the profile of the associated mask) and focus more on supporting against downward hose torque.

As shown in the sectional view ofFIG. 8, each stabilizing member50includes a cavity52which, in the embodiment ofFIGS. 1-8is generally inflated by one or both of the applied system pressure and the exhalation pressure of the patient.

As shown in the example patient interface device110ofFIG. 9, each stabilizing member50may be generally filled with a low durometer gel (e.g.,<10shore A), foam, or other soft material54to modify the stiffness or feel of stabilizing members on the patient's face.

FIG. 10shows a sectional view of another example patient interface device210having stabilizing members250bounded by a grooved portion56which generally allows for each of stabilizing members250to articulate with respect to cushion216. Such articulation further improves the stability of patient interface210by allowing each of stabilizing members250to displace and maintain contact with the maxilla of the patient as the patient moves throughout a sleep cycle. Each of grooved portions56may include one or more baffles/rolls or be comprised of a thinned wall section (with respect to the adjacent wall sections) which allow displacement of each stabilizing member250while also providing for such members250to return to their original position when no force is applied thereto.

FIG. 11shows a sectional view of yet another example patient interface device310having stabilizing members350which are selectively coupled to cushion316via the interaction of one or more coupling mechanisms provided on each stabilizing member350and cushion316. In the example embodiment shown inFIG. 11, such coupling mechanisms include a mushroom shaped protrusion356which extends from cushion316and is engaged by a cooperatively shaped aperture358formed in stabilizing member350. It is to be appreciated, however, that other suitable coupling mechanisms may be employed without varying from the scope of the present invention. It is also to be appreciated that such arrangement allows for the stabilizing members to be selectively replaced, if needed, or custom tailored to fit a particular patient by changing one or more of the size, texture, hardness, etc. of the stabilizing member.

Continuing to refer toFIG. 11, similar to the embodiment shown inFIG. 8, each of stabilizing members350includes a hollow cavity352in fluid communication with cavity18via a channel360formed in each mushroom shaped protrusion356. Such arrangement provides for each cavity352to be generally inflated by one or both of the applied system pressure and the exhalation pressure of the patient.

FIG. 12shows a sectional view of a further example patient interface device410similar to that shown inFIG. 11, except each selectively coupled stabilizing member450includes a sealed cavity452which is not in communication with cavity18. In such arrangement, cavity452may be filled with air of a predetermined pressure in order to provide a selected stiffness for each member450. As shown in the example patient interface510ofFIG. 13, each stabilizing member550may similarly be generally filled with a low durometer gel, foam, or other soft material554to modify the stiffness or feel of the stabilizing members550on the patient's face.

Although only one pair of stabilizing members50,150,250,350and450are included in the example embodiments ofFIGS. 8-13, it is to be appreciated that one or more of the quantity, size or shape of such stabilizing members may be modified without varying from the scope of the present invention.

As yet another stabilizing feature, the embodiment ofFIGS. 1-8further includes a number of ridges60(FIGS. 6-8) running generally between front side20and rear side22on the bottom of cushion16thus generally connecting the facial contact area to the front portion28and the headgear (not shown) coupled thereto. The localized increase in material thickness provides additional stability against patient interface device10rocking toward the nares of the patient.

FIG. 15Ais a top cross-sectional view andFIG. 15Bis a side view of a further embodiment of a patient interface device600according to the principles of the present invention. In this embodiment, patient interface device600includes a cushion610and stabilizing members612provided on each side of the cushion. In addition, the patient interface device includes a maxilla support assembly630that serves to transfer strapping forces to the maxilla supports, as indicated by arrows A. Maxilla support assembly630also helps to maintain the curvature of the cushion, i.e., prevent the cushion from collapsing as the cushion is forced against the face of the user.

Maxilla support assembly630includes a first portion632operatively coupled to a proximal end of cushion610and/or an elbow coupling602and a second portion634operatively coupled to stabilizing members612. A support member636spans between first portion632and second portion634. In this embodiment, the maxilla support assembly is intended to be as minimal as possible, and extends from the elbow coupling into a pocket (not shown) within the stabilizing member. The use of maxilla support assembly is particularly helpful in situations where the cushion is formed from a relatively low durometer.

The present invention contemplates that any portion of the maxilla support assembly630can be provided within the cavity defined by the cushion, provided in the wall of the cushion itself, provided external to the cushion, or any combination thereof. The maxilla support assembly is formed from a sufficiently rigid or semi-rigid material so as to transfer the forces to the stabilizing members. In an exemplary embodiment, at least a portion of the maxilla support assembly is flexible so as to allow flexing of the cushion as the strapping force is changed.

The maxilla support assembly can be formed from a variety of materials and can be either permanently or selectively attachable to the cushion and/or elbow coupling. In addition, the various components of the maxilla support assembly can have any one of a variety of sizes, shapes and geometries.FIGS. 16A and 16Billustrate examples of other such configurations for maxilla support assembly630aand630b.