Patent Description:
NIV masks commonly are used on patients who also require an NG, NJ and/or OG tube for feeding or delivery of medication. Traditionally, NIV masks are not designed for use in combination with an NG, NJ and/or OG tube and, as such, the efficacy of the NIV therapy can be compromised when such a combination is desired.

Traditional NIV masks have a silicone or thermoplastic elastomer (TPE) seal/cushion that conforms to a patient's face in order to create an air-tight seal. These cushions generally are flexible but not to an extent that allows the cushion to conform to very small features. In circumstances where an NG, NJ and/or OG tube is desired to be used in combination with an NIV mask, it is typical for the mask to be placed over the top of the tube(s). The tube(s) lift the cushion away from the patient's face, creating gaps around the tube that cause the seal to be broken and allow leaks to occur.

There are several techniques currently used to minimize gaps and to reduce leaks. These techniques include strapping the mask tighter onto the patient, using an adhesive pad to fill the gaps between the tube, cushion and patient's face, or passing the NG, NJ and/or OG tube through a port in the mask. Strapping the mask tighter can be uncomfortable for the patient and can lead to pressure-related skin damage. It also is possible that the NG, NJ and/or OG tube may be deformed by the tight fit of the mask and this could lead to blockages within the tube. The use of an adhesive pad creates extra work for the clinician who is fitting the NG tube or other tube and mask because it is another component that has to be fitted and aligned. In addition, the pad may not be successful in blocking the gaps effectively if the tube is too large or small or if the tube and/or the pad are misaligned. Passing the NG, NJ and/or OG tube through a port in the mask eliminates any breaks in the seal caused by the tube but often requires the tube to be removed in order to remove the mask. Removing and replacing NG, NJ and/or OG tubes can be uncomfortable and can cause irritation to the patient.

<CIT> discloses a non-invasive ventilation patient interface comprises a frame, a facial skin interface, and a self-sealing tube insertion region. The frame is configured for coupling with a head strap system, where head strap system is configured for supplying a securing force to secure the patient interface in a position over a respiratory opening of a patient. The facial skin interface is coupled with the frame and configured for interfacing with facial skin of the patient and sealing the patient interface about the respiratory opening in response to the securing force. The self-sealing tube insertion region is coupled with the facial skin interface and configured for self-sealing about a tube disposed between the facial skin and the facial skin interface, such that the securing force is diverted around the tube while the tube is inserted in the self-sealing tube insertion region.

<CIT> discloses a flow-inflating respiratory face mask is disclosed that includes a thin, pliant skirt that surrounds the base of the face mask. The skirt inflates automatically when the face mask receives external pressurized air. The skirt is compliant, soft, and adapts easily to the topography of the face which produces a good fit and adds to the comfort of the patient. <CIT> relates to a mask for delivery of gas, such as oxygen, useable in a naso-gastric intubation procedure without disruption of the seal between the mask and the face of the patient.

The systems, methods and devices described herein have innovative aspects, no single one of which is indispensable or solely responsible for their desirable attributes. Without limiting the scope of the claims, some of the advantageous features will now be summarized.

Certain features, aspects and advantages of the embodiments include a respiratory mask with a cushion that is designed to accommodate an NG, NJ and/or OG tube passing between the mask and a patient's face. The cushion has specific thin regions that are designed to conform to the geometry of an NG, NJ and/or OG tube, which regions can help to reduce or minimize leak-causing gaps that might be otherwise created between the cushion and the patient's face.

In some configurations, a cushion for a respiratory mask includes a face contacting portion and at least one thin region at least partially within the face contacting portion. The thin region is adapted to accommodate the placement of a tube between the face contacting portion and a face of a user.

In some configurations, in use, the at least one thin region is adapted to conform to a shape of the tube while substantially maintaining an adequate seal with the face of the user.

In some configurations, the at least one thin region is located on a lateral side of the face contacting portion.

In some configurations, the at least one thin region comprises a thin region on each lateral side of the face contacting portion.

In some configurations, the thin region on one lateral side is a relatively larger thin region and the thin region on the other side is a relatively smaller thin region.

In some configurations, the at least one thin region comprises two or more thin regions on one lateral side of the face contacting portion. In some configurations, a first thin region and a second thin region of the two or more thin regions are spaced apart from one another. In some configurations, the first thin region and the second thin region are spaced apart along a perimeter of the face contacting portion. In some configurations, the two or more thin regions comprise at least one relatively larger thin region and at least one relatively smaller thin region.

In some configurations, the at least one thin region extends in a direction from an inner edge of the face contacting portion toward an outer edge of the face contacting portion.

In some configurations, the at least one thin region extends downwardly relative to a horizontal axis from an inner end portion to an outer end portion. In some configurations, the at least one thin region extends downwardly at an angle of between about <NUM> degrees and about <NUM> degrees.

In some configurations, the cushion includes a smooth transition in thickness between the at least one thin region and an adjacent portion of the face contacting portion. In some configurations, the transition is substantially linear.

In some configurations, a thickness of the at least one thin region is between about <NUM> percent and about <NUM> percent of a thickness of an adjacent portion of the face contacting portion. In some configurations, the thickness of the at least one thin region is between about <NUM> percent and about <NUM> percent of the thickness of the adjacent portion of the face contacting portion.

In some configurations, end portions of the at least one thin region are rounded.

In some configurations, the inner end portion of the at least one thin region is spaced outwardly from the inner edge of the face contacting portion.

In some configurations, the outer end portion of the at least one thin region is spaced inwardly from the outer edge of the face contacting portion.

In some configurations, the tube is a feeding tube.

In some configurations, the cushion comprises a visual alignment indicator that indicates a proper location of the tube.

In some configurations, a patient interface includes a cushion comprising a face contacting portion and at least one thin region at least partially within the face contacting portion. The thin region is adapted to accommodate the placement of a tube between the face contacting portion and a face of a user.

In some configurations, the cushion is adapted to create a seal around the user's nose and/or mouth.

In some configurations, the cushion is configured such that an upper portion of the cushion can be deflected forward relative to a lower portion of the cushion.

In some configurations, a headgear retains the patient interface on the head of a user. In some configurations, a frame portion interfaces with the headgear and the cushion interfaces with the frame portion.

In some configurations, the cushion comprises a relatively soft portion defining the face contacting portion and a relatively rigid portion facing away from the relatively soft portion.

In some configurations, the at least one thin region comprises two or more thin regions on one lateral side of the face contacting portion.

In some configurations, the at least one thin region extends downwardly relative to a horizontal axis from an inner end portion to an outer portion.

In some configurations, the cushion includes a smooth transition in thickness between the at least one thin region and an adjacent portion of the face contacting portion.

In some configurations, the patient interface includes a visual alignment indicator that indicates a proper location of the tube.

Throughout the drawings, reference numbers can be reused to indicate general correspondence between reference elements. The drawings are provided to illustrate example embodiments described herein and are not intended to limit the scope of the disclosure.

In circumstances where NG, NJ and/or OG tubes are used in combination with NIV masks, undesirably high leak rates are a common occurrence. Having high leak rates can compromise the quality of therapy that a patient receives and the methods currently used to remedy the leaks can result in undesirable side-effects. Certain features, aspects and advantages of the disclosed embodiments seek to provide a useful alternative to currently known approaches of addressing and reducing these leaks.

The following description of certain features, aspects and advantages of certain embodiments refers to respiratory masks designed and configured to be used, or adapted for use, in combination with an NG tube; however, it is to be understood that the mask also can be used in combination with an NJ tube, both an NG tube and an NJ tube, which is more common, or any combination of an NJ tube, NG tube or OG tube. The respiratory masks can also be used, or adapted for use, with other types of tubes that are desired to pass between the mask cushion or seal and the patient's skin. Therefore, references to NG tubes herein can also refer to NJ tubes, OG tube, other tubes (e.g., fluid draining tubes) or any combination of NG tubes, NJ tubes, OG tube and other tubes.

The illustrated respiratory masks are NIV masks; however, the features, aspects and advantages described herein can be applied to other types of masks, as well. Certain features, aspects and advantages of the present masks are described in relation to providing therapy to adults; however, it also is possible to apply certain features, aspects and advantages of the present disclosure to respiratory masks for any age group, including but not limited to neonatal, infant and pediatric patients.

<FIG> illustrates a user or patient <NUM> wearing a respiratory (e.g., NIV) mask <NUM> in combination with an NG tube <NUM>. The illustrated mask <NUM> includes a mask body or interface <NUM>, which includes a cushion or seal <NUM> that contacts the user's face and surrounds the user's nose and/or mouth. The interface <NUM> also includes or is connected to a conduit connector <NUM> that allows the interface <NUM> to be connected to one or more gases conduits (not shown). In the illustrated arrangement, the conduit connector <NUM> is in the form of an elbow. A headgear <NUM> is coupled to the interface <NUM> and retains the interface <NUM> in position on the user's face.

The interface <NUM>, conduit connector <NUM> and headgear <NUM> can take on many different forms. For example, the interface <NUM> can be a nasal interface, which covers only the user's nose, or a full face interface, which covers both the nose and mouth. Although a full face interface <NUM> is illustrated, the present disclosure can apply to other interface types in which a tube is desired to be passed between the interface cushion or seal and the user's face. The interface <NUM> can include or omit a forehead rest. In addition, the interface <NUM> (and, in some arrangements, the conduit connector <NUM>) can be a one-piece structure or, as illustrated, can be an assembly of several components. The illustrated interface <NUM> includes a cushion module <NUM>, which in some configurations includes a relatively rigid housing <NUM> and the relatively soft seal <NUM>. The interface <NUM> also includes a frame <NUM>, which can support the cushion module <NUM> and can provide connection or anchor locations for the headgear <NUM>. The headgear <NUM> can be of any suitable arrangement, including single loop or multi loop arrangements.

It is typical for the NG tube <NUM> to be run from the nose towards the cheek and out the side of the mask <NUM>. In a conventional mask, as illustrated by the dashed lines in <FIG>, this arrangement can result in the formation of gaps between the mask seal and a corresponding surface of the user's face <NUM>. While flexible, the conventional cushion is not capable of conforming to the geometry of the tube <NUM> to a degree necessary to prevent undesirably high rates of gas leakage through the gaps between the cushion and the user's face <NUM>. Instead, a relatively large length of the cushion lifts away from the user's face <NUM> and curves over the tube <NUM> leaving gaps on either side of the tube <NUM> where leaks can occur. In general, the larger the diameter of the NG tube <NUM>, the larger the size of the gaps.

Certain features, aspects and advantages of the present embodiments seek to reduce the gaps that form between the mask cushion <NUM> and the surface of the user's face <NUM> when an NG tube <NUM> is used by providing a conformable or compliant region <NUM> in the mask cushion <NUM> that can conform to the NG tube <NUM> to a degree sufficient to create or maintain an adequate seal with the user's face <NUM>. The conformable or compliant region <NUM> can be of any suitable arrangement to increase the conformability or compliance of a portion of the cushion <NUM> relative to adjacent or surrounding portions of the cushion <NUM>. As described herein, the conformable or compliant region <NUM> can be or comprise a region of thinned material or a region of different material, among other possible arrangements.

Preferably, the conformable or compliant region <NUM> can allow the present cushion <NUM> to create or maintain a better seal with the user's face <NUM> than a conventional mask cushion. In some configurations, the present cushion <NUM> can accommodate an NG tube <NUM> with less gas leakage between the cushion <NUM> and the user's face <NUM> in comparison to a conventional cushion. In some configurations, the present cushion <NUM> can accommodate an NG tube <NUM> with no or substantially no gas leakage between the cushion <NUM> and the user's face <NUM> or gas leakage that is below a rate considered to be detrimental to the prescribed therapy. In some configurations, the leak rate with the present cushion <NUM> accommodating an NG tube <NUM> within the conformable or compliant region <NUM> is equal to or less than about <NUM>/min at a normal pressure or flow rate range for the prescribed (e.g., NIV) therapy. In some configurations, the leak rate is less than about <NUM>/min, less than about <NUM>/min or less than about <NUM>/min.

<FIG> illustrates a profile view of an NG tube <NUM> passing between the cushion <NUM> and the user's face <NUM>. The conformable or compliant region <NUM> creates a tube path that is more compliant and flexible than the surrounding or adjacent portions of the cushion <NUM>. In some configurations, the conformable or compliant region <NUM> is more compliant and flexible than any other portion of the cushion <NUM>. <FIG> illustrates how the conformable or compliant region <NUM> stretches and deforms around the tube <NUM>, which results in much smaller gaps at the side of the tube <NUM> than a cushion not having the specially configured tube paths. The size of the gaps will be largely dependent on the tube size that is being used. In <FIG>, it is evident that the mask cushion <NUM> does not lift away from the face <NUM> to accommodate the NG tube <NUM> to the same degree as a traditional mask cushion that does not include tube paths.

The NG tube <NUM> has a cross-sectional dimension or diameter <NUM> extending in a direction away from the user's face <NUM>. Preferably, the conformable or compliant region <NUM> allows the cushion <NUM> to contact or conform to at least a substantial portion of the NG tube <NUM> that is not in contact with the user's face <NUM>. In some configurations, the conformable or compliant region <NUM> allows the cushion <NUM> to remain in contact with or conform to at least the outer one-third <NUM> of the surface of the NG tube <NUM> that is opposite the user's face <NUM>. In some configurations, the conformable or compliant region <NUM> allows the cushion <NUM> to remain in contact with or conform to at least the outer one-half <NUM> of the surface of the NG tube <NUM>. In some configurations, the conformable or compliant region <NUM> allows the cushion <NUM> to remain in contact with or conform to at least the outer two-thirds <NUM> of the surface of the NG tube <NUM>. In some configurations, the conformable or compliant region <NUM> allows the cushion <NUM> to remain in contact with or conform to a substantial entirety of the surface of the NG tube <NUM> that is not in contact with the user's face <NUM>.

<FIG> illustrates a profile view of the mask cushion <NUM> of <FIG> being used without an NG tube <NUM>. <FIG> illustrates that the conformable or compliant region <NUM> sits largely against and contacts the user's skin <NUM> when there is no NG tube <NUM> present. The external surface of the conformable or compliant region <NUM> can be shaped such that the conformable or compliant region <NUM> or tube path substantially follows the same contours as the rest of the mask cushion <NUM>. Such a configuration helps the conformable or compliant region <NUM> to seal with the patient's face <NUM>, which will create preferably no more than a negligible leak path in the absence of an NG tube <NUM>. It is beneficial for the conformable or compliant region <NUM> to substantially follow the geometry of the rest of the cushion <NUM> because such a configuration will make the mask <NUM> more versatile and suitable for use on a wider range of users than otherwise possible. For example, the illustrated mask <NUM> can be used on any user or patient requiring NIV therapy, regardless of the need for use with tubes. Preferably, the patient-facing or contacting surface of the conformable or compliant region <NUM> and the patient-facing or contacting surface of the adjacent or surrounding portions of the cushion <NUM> define a continuous or uninterrupted surface. That is, preferably, there is no slit or other interruption in the patient-facing or contacting surface within or adjacent to the conformable or compliant region <NUM>.

In some configurations, there may be a slight step in the external surface of the cushion <NUM>. The slight step can be intentional or a result of the materials, configuration or manufacturing process used to create the conformable or compliant region <NUM>. The step can be small enough that it will generate minimal leaks. The conformable or compliant region <NUM> may be flexible enough to inflate under the air pressure that is applied by the therapy such that the ballooning portion will fill any gaps that a step in the surface may otherwise cause.

As described above, the conformable or compliant region <NUM> can be of any suitable arrangement that provides for conformance to the type or size of the tube <NUM> or tubes intended for use with the mask <NUM>. In some configurations, the conformable or compliant region <NUM> is substantially more conformable or compliant than surrounding or adjacent portions of the cushion <NUM>. In some configurations, the increased conformability or compliance is at least partially the result of using a different material in the conformable or compliant region <NUM> relative to surrounding or adjacent portions of the cushion <NUM>. For example, the increased conformability or compliance can be achieved through the localized use of a more elastic and flexible material. The different material can have a higher elasticity or different modulus of elasticity compared to the material of surrounding or adjacent regions of the cushion <NUM>. Materials can include a different grade of silicone that is less hard or a more flexible TPE, for example but without limitation. In some configurations, the different material can also have a different thickness (e.g., less thickness) compared to the material of surrounding or adjacent regions of the cushion <NUM>. The different material can be coupled to the material of surrounding or adjacent regions of the cushion <NUM> by any suitable process, which can include adhesive or chemical bonding or a co-molding or over-molding process, for example and without limitation, or any other appropriate method. In arrangements in which different material is utilized for the conformable or compliant region <NUM>, the different material can extend beyond the conformable or compliant region <NUM>. For example, such an arrangement can provide a greater surface area overlap for bonding of the two materials to one another.

In some configurations, the conformable or compliant region <NUM> is or comprises a region of thinned material. In the illustrated arrangements of <FIG>, the conformable or compliant region <NUM> comprises a region of thinned material that is the same material as the material of surrounding or adjacent regions of the cushion <NUM>. Thus, the thinned material region can be unitarily formed with surrounding or adjacent regions of the cushion <NUM>. Hereinafter, the conformable or compliant region <NUM> may be referred to as a thin region or thinned region. However, in view of the alternative structures for the conformable or compliant region <NUM>, such references to a thin region can also generally include other types of conformable or compliant regions, as well. The conformable or compliant region <NUM> can define a tube path or tube paths that accommodate the passage of the NG tube <NUM> or other tubes between the cushion <NUM> and the user's face <NUM> and, thus, can also be referred to herein as a tube path. In some configurations, the tube path or tube paths <NUM> are formed to be thinner than the adjacent portions of the cushion <NUM>. In some configurations, the tube path or tube paths <NUM> are formed to be thinner than any other portion of the cushion <NUM>.

<FIG> illustrate the cushion module <NUM> separate from other portions of the mask <NUM>. As described, the cushion module <NUM> comprises the housing <NUM> and the seal or cushion <NUM>. In the illustrated arrangement, the conformable or compliant region <NUM> of the seal <NUM> is or comprises a thin region. Preferably, the thin region <NUM> is defined by the seal wall, which thin region <NUM> is more capable of conforming to the tube <NUM> relative to surrounding, adjacent or other portions of the cushion <NUM>. The cushion <NUM> generally has a patient face contacting portion or side <NUM> and a portion or side <NUM> forward of the face contacting portion <NUM>. The face contacting portion <NUM> is generally rearward-facing and contacts the user's face <NUM>. The face contacting portion <NUM> can deform when placed into contact with the user's face <NUM> and an entirety of the rearwardly-facing portion may not contact the face of all users or under all circumstances or therapies. In the illustrated configuration, an upper portion of the cushion <NUM> can be deflected forwardly relative to a lower portion of the cushion <NUM> to better accommodate variations in the nasal geometry of potential users. Examples of such an arrangement are disclosed in Applicant's <CIT>. The cushion <NUM> can be made from one or more generally flexible materials, such as silicone or a TPE, for example but without limitation.

A location of the thin region <NUM> is illustrated by an outline on an exterior surface of the cushion <NUM> in <FIG> and <FIG>. However, preferably, the thin region <NUM> is defined by a recess <NUM> defined by an interior surface of the cushion <NUM>, as illustrated in <FIG>. The geometry of the thin region <NUM> can be configured or adapted to conform to a size or shape of the tube(s) intended for use with the mask <NUM>. In some configurations, the thin region <NUM> can be positioned at least partially or entirely within the face contacting portion <NUM> of the cushion <NUM>. With reference to <FIG>, the thin region <NUM> extends generally in a direction from an inner edge <NUM> of the face contacting portion <NUM> towards an outer edge <NUM> of the face contacting portion <NUM>. In some configurations, the thin region <NUM> can be spaced from one or both of the inner edge <NUM> and the outer edge <NUM>. In some configurations, as illustrated in <FIG>, the thin region <NUM> can extend beyond the outer edge <NUM> of the face contacting portion <NUM> and into the forward portion <NUM> of the cushion <NUM>.

In some configurations, the thin region <NUM> is angled relative to a horizontal axis <NUM> of the cushion <NUM> or cushion module <NUM>. A vertical axis <NUM> can bisect the cushion <NUM> or cushion module <NUM> in a vertical direction and the horizontal axis <NUM> is perpendicular to the vertical axis <NUM> and extends in a lateral direction of the cushion <NUM> or cushion module <NUM>. An axis <NUM> of the thin region <NUM> and the horizontal axis <NUM> can define an angle therebetween of between about <NUM> degrees and about <NUM> degrees, or more if desired. In one configuration, the angle between the axis <NUM> and the horizontal axis <NUM> is about <NUM> degrees. In the illustrated arrangement, an inner end <NUM> of the thin region <NUM> closer to the centerline or vertical axis <NUM> is higher than an outer end <NUM> of the thin region <NUM> that is further from the centerline or vertical axis <NUM>. Such an arrangement accommodates the typical path of the NG tube <NUM> as illustrated in <FIG>. However, the thin region <NUM> can be provided in other orientations to suit other applications, as desired. For example, an oro-gastric (OG) tube may extend through the cushion <NUM> at about <NUM> degrees or generally along the horizontal axis <NUM>. Thus, the specific orientation of the thin region <NUM> can be selected as desired in view of the particular tube, tube orientation or other relevant factors.

The thin region <NUM> can have any suitable size or shape to configured or adapted to conform to a size or shape of the tube(s) intended for use with the mask <NUM>. In the illustrated arrangement, the thin region <NUM> defines substantially linear side edges <NUM> and <NUM> extending between the inner end <NUM> and the outer end <NUM>. The side edges <NUM> and <NUM> can be substantially parallel to one another. The axis <NUM> can be defined as a line parallel to an equidistant from the side edges <NUM>, <NUM>. In some configurations, one or both of the inner end <NUM> and the outer end <NUM> can have a rounded or substantially semi-circular profile, as shown in <FIG> and <FIG>. This geometry will result in the thicker side-wall structure of the cushion <NUM> butting up to the circumference of the NG tube <NUM>, and the thin region <NUM> deforming between the thicker side-wall and the tube <NUM>. The thin region <NUM> can be thin enough to deform and stretch over an NG tube <NUM> for which the mask <NUM> is intended or approved for use without significantly lifting the cushion <NUM> away from the patient's face <NUM>. In some configurations, no lift or substantially no lift will occur. The rounded geometry of the ends <NUM>, <NUM> of the conforming region <NUM> can minimize the likelihood of the NG tube <NUM> being deformed or constricted by the relatively thicker adjacent wall portion of the cushion <NUM>.

<FIG> show cross-sectional views of the thin conforming region <NUM> of the cushion <NUM>. In the illustrated configuration, the internal surface of the cushion <NUM> may reduce or step down from a relatively thicker wall section to the relatively thinner and more conformable portion <NUM> to define the interior recess <NUM> while the external surface can remain substantially unchanged. In other words, the external surface is continuous and uninterrupted between the thin region <NUM> and the adjacent or surrounding portions of the cushion <NUM>. However, in some configurations, the external surface could include a recess in addition to or in the alternative to the internal recess <NUM> and ballooning a result of internal gas pressure could be relied on to create a seal with the user's face <NUM> in the absence of a tube <NUM>.

The recess <NUM> can define a length <NUM> in a direction along the axis <NUM> and a height <NUM> in a direction perpendicular to the axis <NUM>. The length <NUM> can be selected to extend along a length of the face contacting portion <NUM> that is likely to be in contact with the user's face <NUM> under typical or expected operating conditions. In some configurations, the length <NUM> is between about <NUM> and about <NUM>. The length <NUM> can vary with the size of the cushion <NUM> or can remain constant between different sized cushions <NUM>. For example, the length <NUM> can vary from about <NUM> in a small cushion <NUM> to about <NUM> or <NUM> for a large cushion <NUM>. The height <NUM> can be selected to accommodate the diameter or cross-sectional dimension of the tube(s) with which the mask <NUM> is designed or intended to be used. In some configurations, the height <NUM> is substantially equal to somewhat larger than the diameter of the maximum tube size with which the mask <NUM> is designed or intended to be used. In some configurations, the height <NUM> is between about <NUM> and about <NUM>, or between about <NUM> and <NUM>. The height <NUM> can vary with the size of the cushion <NUM>, such as about <NUM> for an extra small cushion, about <NUM> for a small and medium cushion and about <NUM> for a large cushion. Alternatively, the height <NUM> can remain constant between cushion sizes.

The thin region <NUM> defines a wall thickness <NUM> that is less than a wall thickness <NUM> of portions of the cushion <NUM> adjacent to or surrounding the thin region <NUM>. Preferably, the wall thickness <NUM> of the thin region <NUM> is less than the wall thickness <NUM>. In some configurations, the wall thickness <NUM> is about <NUM> percent to about <NUM> percent or about <NUM> percent to about <NUM> percent of the wall thickness <NUM>. In some configurations, the wall thickness <NUM> represents a reduction in thickness relative to the wall thickness <NUM> of between about <NUM> percent to about <NUM> percent, or about <NUM> percent to about <NUM> percent. For example, in some configurations, the wall thickness <NUM> can be about <NUM> or <NUM> and the wall thickness <NUM> can be between about <NUM> and about <NUM>, or between about <NUM> and about <NUM>. In some configurations, the wall thickness <NUM> is about <NUM>. The wall thickness <NUM> within the recess <NUM> is illustrated as substantially constant (not including the transition portions between the recess <NUM> and the surrounding or adjacent portions of the cushion <NUM>). However, in other arrangements, the wall thickness <NUM> can vary within the recess <NUM>.

The cushion <NUM> can define a depth <NUM> (<FIG>) in a forward-rearward direction from a rearward most point on the patient contacting portion <NUM> at a height of the thin region <NUM> and a location of the outer end <NUM> of the thin region <NUM>. Having a sufficient depth <NUM> can assist the cushion <NUM> to remain in contact with the user's face <NUM> with an NG tube <NUM> in place. However, preferably, the depth <NUM> is not too large, or the thin region <NUM> does not extend too far toward or into the forward portion <NUM> of the cushion <NUM> to avoid unnecessary weakening of the cushion <NUM>. The depth <NUM> can be related to the size of tube <NUM> with which the mask <NUM> is designed, intended or approved for use. In some configurations, the depth <NUM> is between about <NUM> and about <NUM>, or between about <NUM> and about <NUM>. The depth <NUM> can vary with the size of the cushion <NUM>, such as about <NUM> or <NUM> for an extra small cushion, about <NUM> or about <NUM> for a medium cushion and about <NUM> or <NUM> for a large cushion. Alternatively, the depth <NUM> can remain constant between cushion sizes.

In some configurations, the transition in thickness between the recess <NUM> and the adjacent or surrounding portions of the cushion <NUM> can be relatively abrupt. The abrupt transition can create a fold point that restricts deformation that may be caused by a tube to the relatively thinner region <NUM> of the cushion <NUM>. The relatively thinner region <NUM> can deform, stretch and/or bunch up until a relatively thicker wall portion is encountered, which can limit any further deformation. In other configurations, the transition in thickness can be less abrupt, as illustrated by the dashed lines at the edges of the recess <NUM> in <FIG>. A smooth or less abrupt transition may be preferred for other reasons, such as manufacturability reasons, for example. Preferably, the transition is limited to a relatively small distance from the recess <NUM> or relatively small area surrounding the recess <NUM>. For example, the transition can be substantially linear and/or can be an angle sufficient to allow the practical removal of a molded cushion <NUM> having the thin region <NUM> from a mold. In some configurations, the transition region preferably extends away from the thin region <NUM> a distance of no more than the width or length of the thin region <NUM> and, preferably, extends no more than a portion of the width or length of the thin region <NUM> (e.g., less than one-half, one-third or one-quarter of the width or length of the thin region <NUM>).

<FIG> illustrates one example of an outline of a recess or thin region <NUM> in a flattened condition. In practice, the thin region <NUM> is likely to be curved or three-dimensional in shape because many patent contacting surfaces of mask cushions are curved in lateral and/or vertical directions. In <FIG>, each end <NUM>, <NUM> of the thin region <NUM> is semi-circular in shape about a respective center <NUM>. Thus, a distance <NUM> between the centers <NUM> plus the radius of each end <NUM>, <NUM> equals the overall length <NUM> of the thin region <NUM>. In the illustrated thin region <NUM>, the side edges <NUM>, <NUM> are parallel to one another and each end <NUM>, <NUM> is of an equal radius. However, in other arrangements, the thin region <NUM> can have other suitable shapes.

In some configurations, such as that shown in <FIG>, the conforming thin regions or tube paths <NUM> can be provided in multiple locations. <FIG> shows a rear view of the cushion <NUM> with two tube paths <NUM> spaced from one another along a perimeter of the cushion <NUM> and symmetrically located on each side of the mask <NUM>. Having paths <NUM> on each side of the mask <NUM> allows for an NG tube <NUM> to be secured to either side of the patient's face <NUM>. It is common practice for NG tubes <NUM> to be alternated between a patient's nostrils in order to reduce irritation and tissue damage within the nasal passage. Having symmetrical tube paths <NUM> on the mask <NUM> enables a clinician to change the side that the NG tube <NUM> is secured to and to continue to use the same mask <NUM>. Such a configuration reduces wastage of equipment and may reduce work for the clinicians. Additionally, having tube paths <NUM> on both sides enables a cushion <NUM> to seal when both an NG tube <NUM> and an NJ tube are in simultaneous use.

Also shown in <FIG> are two different tube path <NUM> sizes. Because NG tubes <NUM> come in a variety of sizes, it is beneficial for the tube paths <NUM> to be able to conform to any size or at least commonly used sizes. It may be desired to have more than one path size in a mask <NUM> in order to cover a wider range of tube diameters with at least acceptable leak-rate performance. If a tube is too small for the tube path <NUM>, the relatively thicker wall section of the cushion <NUM> may not be able to adequately restrict the deformation of the thin region <NUM> and gaps may form, which gaps can result in leaks. The size of the tube path <NUM> can be defined to suit a certain range of tube diameters. It is desirable for the round/circular profile of the tube path <NUM> to generally correlate to or match the tube diameter, as discussed above. By closely matching or generally correlating the tube path <NUM> to the tube <NUM>, the relatively thicker wall section can force the thin region <NUM> to conform around the tube <NUM>.

It is preferable not to have too many tube paths <NUM> or tube paths <NUM> that are too large because they can reduce the structural integrity of the cushion <NUM>. The relatively thicker wall-section of the cushion <NUM> can be designed to provide structure and support to the mask <NUM>. The cushion <NUM> can be provided with structure to reduce or eliminate the likelihood of the cushion <NUM> collapsing when the mask <NUM> is strapped on to a patient <NUM>. If the cushion <NUM> collapses, leaks can occur and the rigid plastic mask frame <NUM> can be pushed against the patient's face <NUM> causing discomfort. Therefore, the number and size of tube paths <NUM> may be limited so that the structure of the cushion <NUM> is less likely to be compromised. The cushion <NUM> can include any single one or any combination of the tube paths <NUM> illustrated in <FIG>, for example. In some configurations, the cushion <NUM> can include a single tube path <NUM> on one side or a single tube path <NUM> on each side. In configurations with at least one tube path <NUM> on each side, the tube paths <NUM> can be the same size or a different size. For example, the cushion <NUM> can include a relatively smaller tube path <NUM> on one side and a relatively larger tube path <NUM> on the other side. In some configurations, the cushion <NUM> includes a small and a large tube path <NUM> on each side.

Typically, NG tubes <NUM> are run from the underside of a patient's nose across their lip and out across the cheek. The tube <NUM> usually is secured to the nose with tape. The one or more tube paths <NUM> preferably are located on the cushion <NUM> such that they align approximately with the lower surface of a patient's nose or somewhat lower so that the tubes <NUM> can be secured to the patient <NUM> in approximately the conventional location for ease of use by the clinician. It can be beneficial for the tube <NUM> to be positioned over the soft part of a patient's cheek, anywhere below the zygomatic bone, to minimize the occurrence of pressure sores. Having the tube paths <NUM> located in such a way on the cushion <NUM> will enable clinicians to continue using traditional techniques for fitting and securing NG tubes <NUM>. In some configurations, the tube paths <NUM> are located in the lower half of the cushion <NUM> or the lower third of the cushion <NUM>. The tube paths <NUM> can be located at, near or somewhat above a widest point of a full face cushion <NUM>. In some configurations, the tube paths <NUM> are spaced above a lowermost point of an inner edge of the cushion <NUM>.

<FIG> show embodiments of a cushion module <NUM> of a mask <NUM> having visual alignment indicators <NUM>. The indicators <NUM> are intended to provide clinicians with a visual cue for aligning a mask <NUM> over the top of an NG tube <NUM> on a patient's face <NUM>. For the illustrated masks <NUM> to work effectively, it is desirable for the NG tube <NUM> to be aligned accurately with respect to the tube paths <NUM> on the mask cushion <NUM>. Misalignment may result in increased leak rates. The alignment indicators <NUM> can be in the form of an arrow and label that point towards the NG tube path <NUM>. The indicator <NUM> may be located on the cushion <NUM>, as illustrated in <FIG>, or the mask body (e.g., housing <NUM> or frame <NUM>), as illustrated in <FIG>, proximate to the tube path <NUM>. Embossing, printing, laser etching, molding or other marking techniques can be used to form the indicator <NUM> on the mask <NUM>.

Conditional language used herein, such as, among others, "can," "could," "might," "may," "e.g.," and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features or elements are in any way required for one or more embodiments.

The term "plurality" refers to two or more of an item. The term "about" or "approximately" means that quantities, dimensions, sizes, formulations, parameters, shapes and other characteristics need not be exact, but may be approximated and/or larger or smaller, as desired, reflecting acceptable tolerances, conversion factors, rounding off, measurement error and the like and other factors known to those of skill in the art. The term "substantially" means that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

Numerical data may be expressed or presented herein in a range format. It is to be understood that such a range format is used merely for convenience and brevity and thus should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also interpreted to include all of the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. As an illustration, a numerical range of "about <NUM> to <NUM>" should be interpreted to include not only the explicitly recited values of about <NUM> to about <NUM>, but should also be interpreted to also include individual values and sub-ranges within the indicated range. Thus, included in this numerical range are individual values such as <NUM>, <NUM> and <NUM> and sub-ranges such as "about <NUM> to about <NUM>," "about <NUM> to about <NUM>" and "about <NUM> to about <NUM>," "<NUM> to <NUM>," "<NUM> to <NUM>," "<NUM> to <NUM>," etc. This same principle applies to ranges reciting only one numerical value (e.g., "greater than about <NUM>") and should apply regardless of the breadth of the range or the characteristics being described.

A plurality of items may be presented in a common list for convenience. Furthermore, where the terms "and" and "or" are used in conjunction with a list of items, they are to be interpreted broadly, in that any one or more of the listed items may be used alone or in combination with other listed items. The term "alternatively" refers to selection of one of two or more alternatives, and is not intended to limit the selection to only those listed alternatives or to only one of the listed alternatives at a time, unless the context clearly indicates otherwise.

Claim 1:
A cushion (<NUM>) for a respiratory mask comprising:
a face contacting portion (<NUM>) that contacts a user's face and surrounds the user's nose and/or mouth;
at least one conformable or compliant region (<NUM>) located within the face contacting portion (<NUM>) and that is more compliant and flexible than the surrounding or adjacent portions of the cushion (<NUM>) such that the conformable or compliant region (<NUM>) stretches and deforms around a tube (<NUM>) so as to be adapted to accommodate the placement of the tube (<NUM>) between the face contacting portion (<NUM>) and a face of a user;
wherein there is no slit or other interruption in an external surface of the face contacting portion (<NUM>) within or adjacent to the conformable or compliant region (<NUM>).