Patent Description:
Interfaces can be used to provide respiratory gases to a user under positive pressure. In configurations in which a nose of a user is covered, the nasal mask typically will overlie a bridge of the nose. Generally, a single seal will circumscribe a portion of the nose of the user.

Such nasal masks commonly are secured to a head of the user with headgear having a t-piece frame that connects to the seal member. In order to sufficiently reduce leakage, the headgear typically is tightened, which results in an elevated pressure being exerted on a bridge of a user's nose. In other words, as the headgear is tightened, the silicone seal typically applies a progressively increasing load on the bridge of the nose. The pressure can be a source of discomfort and, in some circumstances, can lead to pressure sores over time. <CIT> describes a seal assembly having a seal that is over-moulded to a plastic clip. The plastic clip has a series of holes around its perimeter. During manufacture, over moulding of the seal to the clip causes the seal material to flow through the series of holes. During manufacture, the seal material is cured. Once cured, the seal is mechanically linked to the plastic clip via the holes, providing a mechanical joint between the clip and the seal. The holes are located through a raised ridge running around the inside or outside perimeter of the clip.

It is an object of the present disclosure to provide one or more constructions and/or methods that will at least go some way towards improving on the above or that will at least provide the public or the medical profession with a useful choice.

In one aspect, a seal member for an interface assembly comprises a face contacting surface. The face contacting surface comprises an edge that at least partially defines an opening. The face contacting surface also comprises a first cheek surface and a second cheek surface. The first cheek surface comprises a first thickened portion and the second cheek surface comprises a second thickened portion.

Preferably, the first and second thickened portions are formed on an interior surface of the seal member.

Preferably, a distal portion of the seal member is overmoulded onto a clip member. Preferably, the clip comprises a feature that receives a complementary feature of an interface frame. Preferably, the clip member tapers in a distal direction.

In one aspect, a seal member for an interface assembly comprises a face contacting surface. The face contacting surface comprises an edge that at least partially defines an opening. The face contacting surface also comprises an upper lip contacting surface, a first cheek surface and a second cheek surface. A sidewall extends distally of the face contacting surface. The sidewall comprises a first lower corner proximate a transition from the upper lip surface to the first cheek surface. The sidewall comprises a second lower corner proximate a transition from the upper lip surface to the second cheek surface. The first lower corner and the second lower corner have a thicker cross-section compared to portions of the sidewall located vertically above the first lower corner and the second lower corner.

In one aspect, a seal member for an interface assembly comprises a face contacting surface. The face contacting surface comprises an edge that at least partially defines an opening. The face contacting surface also comprises an upper lip contacting surface, a first cheek surface and a second cheek surface. A sidewall extends distally of the face contacting surface. The sidewall comprises a first thickened band extending along a portion corresponding to the first cheek surface and a second thickened band extending along a portion corresponding to the second cheek surface.

Preferably, the sidewall of the seal member has a thicker cross section distal of the first and second thickened bands relative to a cross section proximal of the first and second thickened bands.

In one aspect, headgear for an interface assembly comprises a body. A first lower strap and a second lower strap extend away from the body. A first upper strap and a second upper strap extend away from the body. The first lower strap comprises a first lower strap centerline. The second lower strap comprises a second lower strap centerline. A first upper strap comprises a first upper strap centerline. The first and second lower strap centerlines intersect each other before intersecting the first upper strap centerline.

Preferably, the second upper strap comprises a second upper strap centerline and the first upper strap centerline corresponds to the second upper strap centerline.

Preferably, an intersection of the first lower strap centerline and the second lower strap centerline is offset from the first upper strap centerline by a distance of about <NUM>.

Preferably, the first lower strap centerline intersects the first upper strap centerline at a location about <NUM> from a location where the second lower strap centerline intersects the first upper strap centerline.

Preferably, the first upper strap centerline and a second upper strap centerline correlate to each other and do not intersect the entire body of the headgear.

Preferably, the first lower strap centerline extends at an angle relative to the first upper strap centerline with the angle being between about <NUM> degrees and about <NUM> degrees.

In one aspect, an elbow for use with an interface assembly comprises a body having a proximal end and a distal end. The proximal end and the distal end are at an angle relative to each other and a bend is defined at a transition from the proximal end to the distal end. The bend comprises a plurality of exhaust holes. The plurality of exhaust holes are integrally formed with the body of the elbow.

In one aspect, an elbow for use with an interface assembly comprises a body having a proximal end and a distal end. The proximal end and the distal end are at an angle relative to each other and a bend is defined at a transition from the proximal end to the distal end. The bend comprises a plurality of exhaust holes. One or more of the exhaust holes comprises a conical first portion and trumpet shaped second portion.

Preferably, the conical first portion is an inner portion and the trumpet shaped second portion is an outer portion.

Preferably, the exhaust holes are integrally formed in the body.

In one aspect, an interface assembly comprises a frame with a seal removably connected to the frame. The seal is configured in accordance with any described and/or shown herein.

In one aspect, an interface assembly comprises a frame with headgear removably connected to the frame. The headgear is configured in accordance with any described and/or shown herein.

In one aspect, an interface assembly comprises a frame with a conduit connector being connected to the frame. The conduit connector comprises an elbow that is configured in accordance with any described and/or shown herein.

In one aspect, an interface assembly comprises a frame with a seal and headgear removably connected to the frame. The seal is configured in accordance with any described and/or shown herein and the headgear is configured in accordance with any described and/or shown herein.

In one aspect, an interface assembly comprises a frame with a seal connected to the frame and a conduit connector being connected to the frame. The conduit connector comprises an elbow. The seal is configured in accordance with any described and/or shown herein and the elbow is configured in accordance with any described and/or shown herein.

In one aspect, an interface assembly comprises a frame with headgear connected to the frame and a conduit connector connected to the frame. The conduit connector comprises an elbow. The headgear is configured in accordance with any described and/or shown herein and the elbow is configured in accordance with any described and/or shown herein.

In one aspect, an interface assembly comprises a frame with a seal and headgear connected to the frame and a conduit connector connected to the frame. The conduit connector comprises an elbow. The seal is configured in accordance with any described and/or shown herein. The headgear is configured in accordance with any described and/or shown herein. The elbow is configured in accordance with any described and/or shown herein.

These and other features, aspects and advantages of the present technology will now be described with reference to the drawings of a preferred embodiment, which embodiment is intended to illustrate and not to limit the invention, and in which figures:.

An interface <NUM> that is arranged and configured in accordance with certain features, aspects and advantages of the present technology can provide improvements in the delivery of CPAP therapy, for example but without limitation. In particular, the sealing interface <NUM> may exhibit improved sealing characteristics while limiting pressure applied to a bridge of a nose of a user.

It will be appreciated that the interface <NUM> can be used with any delivery device used in respiratory care generally, including with a ventilator, but the sealing interface <NUM> will be described with reference to use in a humidified CPAP system. The delivery systems also could be VPAP (Variable Positive Airway Pressure), BiPAP (Bi level Positive Airway Pressure) or any other form suitable for use in respiratory therapy.

It will also be appreciated that various features, aspects and advantages of the patient interface <NUM>, while being described in the context of a nasal mask, can be used with any other interface configuration, including oronasal masks and full face masks sealing around the user's nose and mouth, oral masks sealing around the user's mouth, and nasal pillows or other types of masks sealing under the user's nose, for example but without limitation.

With reference to <FIG>, a humidified Continuous Positive Airway Pressure (CPAP) system <NUM> is shown. The illustrated CPAP system <NUM> provides humidified and pressurised gases to the user U through the interface <NUM>, which is connected to a humidified gases transportation pathway or inspiratory conduit <NUM>.

The inspiratory conduit <NUM> is connected to an outlet <NUM> of a humidification chamber <NUM>, which is adapted to contain a volume of water <NUM>. The inspiratory conduit <NUM> may contain a heating configuration (not shown), such as heater wires, for example but without limitation. The heating configuration can heat the walls of the inspiratory conduit <NUM> to reduce condensation of humidified gases within the inspiratory conduit <NUM>.

The humidification chamber <NUM> preferably is formed from a plastics material and may have a highly heat conductive base (e.g., an aluminum base) that is in direct contact with a heater plate <NUM> of a humidifier <NUM>. The humidifier <NUM> employs a controller <NUM> or the like. The controller may comprise a microprocessor-based controller that executes computer software commands stored in an associated memory, for example but without limitation.

The controller <NUM> receives input commands from multiple sources, including a user input interface <NUM> (e.g., a dial). The user input interface <NUM> enables the setting of a predetermined value (e.g., a preset value) of humidity, temperature or other characteristic of the gases supplied to the user U. The controller <NUM> also may receive input from other sources. For example, temperature and/or flow velocity sensors <NUM>, <NUM>, which are connected through a connector <NUM> in the illustrated configuration, can communicate with the controller <NUM>. In addition, a heater plate temperature sensor <NUM> can communicate with the controller.

In response to the user set humidity or temperature value, which can be input via the user interface <NUM>, in combination with other inputs, the controller <NUM> determines when and/or to what level the heater plate <NUM> should be energized to suitably heat the water <NUM> contained within the humidification chamber <NUM>. As the volume of water <NUM> within the humidification chamber <NUM> is heated, water vapour begins to fill the volume of the humidification chamber <NUM> above a surface of the water <NUM>. The water vapour passes out of the outlet <NUM> of the humidification chamber <NUM> with a flow of gases (e.g., air) that is provided from a gases supply <NUM> (e.g., a blower), which enters the humidification chamber <NUM> through an inlet <NUM>.

The gases supply <NUM> preferably includes a flow generator <NUM>, which can be a variable speed fan or can include a variable pressure regulator. In the illustrated configuration, the flow generator <NUM> comprises a variable speed fan. The flow generator <NUM> preferably draws air or other gases through an inlet <NUM>. The flow generator <NUM> can be controlled by a controller <NUM> or can be controlled by the controller <NUM>, for example but without limitation. The controller <NUM> may control the fan speed, the regulated pressure or the like according to any suitable criteria. For example, the controller <NUM> may respond to inputs from the controller <NUM> and a user set value (e.g., a preset value) of pressure and/or fan speed, which can be set with a user interface <NUM> (e.g., a dial).

With reference now to <FIG> and <FIG>, the interface <NUM> generally comprises a mask assembly <NUM>. The mask assembly <NUM> generally comprises a frame <NUM>, a seal <NUM> and a clip <NUM> that is used to secure the seal <NUM> to the frame <NUM>. The mask seal <NUM> and the clip <NUM> can be separately formed and secured together or, in some configurations, the mask seal <NUM> and the clip <NUM> can be integrated into a single component. In the illustrated configuration, the mask seal <NUM> is overmoulded onto the mask seal clip <NUM>. A connector <NUM> connects a breathing conduit (not shown) to the mask frame <NUM>.

With reference now to <FIG>, the seal <NUM> is shown from the rear, which is the surface that bears against a face of the user. The seal <NUM> comprises a face contacting surface <NUM>. As shown in <FIG>, the face contacting surface <NUM> preferably comprises an edge <NUM> that at least partially defines an opening <NUM>. In the illustrated configuration, the edge <NUM> surrounds the opening <NUM>. The opening <NUM> is designed to accommodate at least the lower portion and tip of a nose of the user. Preferably, the opening <NUM> is generally T-shaped, albeit an inverted T-shape.

The face contacting surface <NUM> generally comprises a lip surface <NUM>, which is adapted to contact the face of the user at a location above the vermillion border and below the nares. The face contacting surface <NUM> also comprises two separate cheek surfaces <NUM>, which extend between the lip surface <NUM> of the face contacting surface <NUM> and a lateral surface <NUM> of the face contacting surface <NUM>. The cheek surfaces <NUM> can contact the medial cheek surface of the user and/or the lateral nose surface of the user. The lateral surface <NUM> can extend over the nose of the user to connect the two cheek surfaces <NUM>. Other configurations are possible.

As shown in the sectioned perspective view of <FIG>, the face contacting surface <NUM> preferably comprises the thinnest cross section of material in the seal <NUM>. The face contacting surface <NUM> advantageously can easily deform to substantially seal against the facial contours of the user, including one or more of the upper lip, the medial cheek, the lateral nose and the bridge of the nose. Advantageously, the thin cross section of the face contacting surface <NUM> over the lips of the user allows for increased stretchability and results in minimal pressure being applied to the region above the lips of the user. The seal <NUM> can have any suitable configuration. In the illustrated embodiment, the seal <NUM> is an inflating type. As such, the pressure contained within the seal <NUM> can urge the face contacting surface <NUM> against the face of the user.

With reference again to <FIG>, the illustrated seal <NUM> also comprises two thickening panels <NUM>, which are shown in hidden lines. The panels <NUM> generally are positioned along upper portions of the cheek surfaces <NUM>, close to a transition from the cheek surfaces <NUM> to the lateral surface <NUM>. The panels <NUM> can be formed on an interior surface of the seal <NUM>. The panels <NUM> represent locally thickened regions that have been found to enhance the sealing capability of the seal <NUM>. It presently is believed that the panels <NUM> increase a lateral pressure against the lateral nose surface of the user, which allows pressure from the seal <NUM> to better contour to the shape of the nose of the user. In other words, the panels <NUM> may cause a pinching effect on the lateral sides of the nose of the user to allow the pressure from the seal <NUM> to better contour to the shape of the nose of the user.

With reference to <FIG> and <FIG>, the inside surface of the seal <NUM> further comprises at least one thickened band <NUM>. While a single thickened band <NUM> is shown in <FIG> and <FIG>, in some configurations, two or more thickened bands or thickened regions can be provided keeping in mind a desire to achieve the characteristics provided by the thickened band <NUM>.

The illustrated thickened band <NUM> is positioned along a sidewall <NUM> of the seal <NUM>. The sidewall <NUM> extends forwardly from the face contacting surface <NUM>. The band <NUM> preferably comprises a larger lower region <NUM> on an inside of each lateral side of the seal <NUM> and a thinner connecting rib <NUM> that extends between the lower regions <NUM> by wrapping around the upper portion of the inside of the seal <NUM>. When the seal <NUM> receives pressure from the system <NUM>, the thickened band <NUM> helps to reduce the likelihood of, and/or the degree of, the sidewall <NUM> ballooning outward. Ballooning outward of the sidewall <NUM> can cause undesired changes in a shape of the seal <NUM>, which can adversely impact performance of the seal <NUM>.

With reference to <FIG>, the sidewall <NUM> preferably comprises a thin walled proximal portion <NUM> (i.e., close to the face of the user) and a thin wall distal portion <NUM> (i.e., away from the face of the user). The thin walled proximal portion <NUM> is connected to the thin walled distal portion <NUM> with the thickened band <NUM>. Preferably, the face contacting surface <NUM> forms a flange that curls inward from the thin walled proximal portion <NUM>. More preferably, the face contacting surface <NUM> tapers away from the proximal portion <NUM> of the sidewall <NUM>.

With reference to <FIG> still, the distal portion <NUM> curls inward toward the clip <NUM> at a shoulder <NUM>. In some configurations, the distal portion <NUM> curls inward toward a rim <NUM> at the shoulder <NUM>. In the illustrated configuration, the rim <NUM> is overmoulded with a portion of the clip <NUM>.

The shoulder combined with the thin wall distal portion <NUM> and the thickened band <NUM> allows the seal <NUM> to exhibit a rolling action similar to that disclosed in <CIT>, <CIT>, <CIT>, <CIT> and International Patent Application No. <CIT>. The rolling action is represented rather schematically in <FIG> by the dash-dot line and indicated by reference letter R. The distal portion of the seal <NUM> can pivot about a hinge point H while the distal most portion will roll over itself in the region of the shoulder, as indicated by the rolled portion R shown in dash-dot line in <FIG>.

The thin wall distal portion <NUM> and the tighter radius of the shoulder <NUM> helps to cause a controlled buckling and rolling of the seal <NUM>. In addition, when under pressure from the system <NUM>, the internal pressure facilitates the rolling action by reducing the likelihood of the seal sticking upon itself in the rolling region. Moreover, the stiffened band <NUM> extends downward toward the hinge point H but need not extend below the hinge point H. The stiffened band <NUM> also acts as a limit to the degree to which the distal portion <NUM> can roll and deform. Thus, the distal portion <NUM> can only roll until the thickened band <NUM> abuts the rim <NUM>.

In addition, by positioning the thin walled proximal portion <NUM> between the stiffened band <NUM> and the face contacting surface <NUM>, the thin walled proximal portion <NUM> can deform slightly during donning of the mask assembly <NUM>. Preferably, the thin walled proximal portion <NUM> may deform to some degree before the distal portion <NUM>. The rolling effect provides an enhanced comfort level for the user. Advantageously, the rolling effect allows the shape of the seal <NUM> to change to accommodate a wide range of nasal bridge heights while maintaining minimal changes to load.

With reference to <FIG>, a graphical depiction is provided of test data showing a difference provided by the rolling effect. Two masks, a prior art nasal mask sold by Fisher & Paykel Healthcare under the trademark Zest™ was compared to a prototype mask having a rolling effect. Deformation of the masks in the nose bridge region was shown as a function of the force required to create the deformation. As illustrated, over a full range of deformation, the prototype mask remained well below <NUM> N while the prior art mask exceeded <NUM> N of force over the same range of deformation. Moreover, as shown in <FIG>, at all distances of deformation, the prototype mask was well below the prior art mask. Thus, the total force from no displacement to full displacement of the prototype mask was about <NUM> N. Moreover, the increase in force experienced over the final <NUM> (e.g., <NUM> to <NUM> displacement) of displacement was less than about <NUM> N.

With reference to <FIG>, an alternative embodiment of an interface assembly <NUM> includes a seal <NUM> having at least one lower thickened band <NUM> in addition or alternative to the thickened band <NUM>. With the exception of the at least one lower thickened band <NUM> and other features described below, the interface assembly <NUM> of <FIG> is the same as or similar to the interface assembly <NUM> of <FIG>. Therefore, the same reference numbers are used to denote the same or corresponding components or features in both embodiments. With particular reference to <FIG>, preferably, lower thickened band <NUM> is provided in addition to the thickened band <NUM>. The lower thickened band <NUM> is located within a lower portion of the seal <NUM> and, preferably, within a lower half of the seal <NUM> and/or below the thickened band <NUM>. The thickened band <NUM> is positioned along a lower portion of the sidewall <NUM> of the seal <NUM> and preferably is generally or substantially aligned in a fore-aft direction with the thickened band <NUM>. However, in other arrangements, the bands <NUM>, <NUM> could be offset from one another in the fore-aft direction. In other alternative arrangements, a portion or all of the thickened bands <NUM> and/or <NUM> could be arranged generally or substantially in a horizontal plane when the seal <NUM> is in an upright position (oriented as in <FIG>). In some such arrangements, one or more thickened bands <NUM> and/or <NUM> could extend generally or substantially in a lateral direction of the seal <NUM>. For example, a single thickened band <NUM> or <NUM> could be provided, which, in some arrangements, could be generally or substantially at a mid-line of the seal <NUM>. Alternatively, two or more thickened bands <NUM> or <NUM> could be provided, which, for example, could be spaced above and below a mid-line of the seal <NUM>. Furthermore, a combination of one or more generally or substantially lateral bands and one or more generally or substantially vertical or circumferential bands could be provided.

The illustrated band <NUM> preferably comprises a larger upper region <NUM> on an inside of each lateral side of the seal <NUM> and a thinner connecting rib <NUM> that extend between the larger upper regions <NUM>. The upper regions <NUM> and/or the connecting rib <NUM> preferably are generally similar in shape to the lower region <NUM> and rib <NUM> of the band <NUM>. However, in the illustrated arrangement, the band <NUM> is scaled down to a somewhat smaller size than the band <NUM> to correspond to the lower portion of the seal <NUM> being somewhat thinner (in a fore-aft direction) than an upper portion of the seal <NUM>. Preferably, the band <NUM> performs a substantially similar or identical function to the band <NUM>. For example, the band <NUM> preferably reduces the likelihood and/or degree of the sidewall <NUM> ballooning outward and allows a lower portion of the seal <NUM> to exhibit a rolling action in a manner similar or identical to that described above with respect to the band <NUM>.

With reference now to <FIG>, three different cross sections are illustrated on a lower right portion of the illustrated seal <NUM>. A lower most cross section, which is proximate to a corner of the illustrated seal <NUM>, carries reference letter A. A slightly higher cross section carries reference letter B and an even higher cross section carries reference letter C. As illustrated, the intermediate cross section B is substantially thicker than the two adjacent cross sections A, C. Although the three cross sections A, B, C are relatively close together, the wide differences in thickness results in the ability to create localized loading against the face of the user.

It presently is believed that the face of the user can tolerate more loads or pressure in certain regions compared to other regions. By increasing the thickness of the side wall <NUM>, forces can be better transmitted through the sidewall <NUM> from the clip <NUM> to the face contacting surface <NUM>. Similarly, reduced thicknesses in the side wall <NUM> results in less force being transmitted between the clip <NUM> and the face contacting surface <NUM> through the side wall. In some configurations, it is believed that the face of the user can better tolerate pressure in the region of the maxilla, just below the zygomatic progress. For this reason, the lower corner regions <NUM> comprise a region of increased thickness (e.g., section B). When coupled with a forehead contact point provided by the frame <NUM>, a triangle support can be defined among the two lower regions <NUM> of the seal <NUM> and the forehead contact point. The triangular support provides a stable platform on the face that can help resist dislodging during use.

To permanently attach the seal <NUM> to the clip <NUM>, overmolding can be used. With reference to <FIG>, the clip <NUM> is shown without the seal <NUM> attached. The clip <NUM> can be formed of any suitable rigid or semirigid material. In one configuration, the clip <NUM> is formed from a polycarbonate material. Because the seal <NUM> preferably is formed from a silicone material and because the clip <NUM> is formed from a polycarbonate material, a retention structure <NUM> has been provided on the clip <NUM> to allow the seal <NUM> to be secured overmoulded onto the clip <NUM>. In other words, the silicone material of the seal <NUM> generally does not adhere to the polycarbonate material of the clip <NUM> so the seal <NUM> is retained on the clip <NUM> by positively locking the silicone material around features of the retention structure <NUM>.

The retention structure <NUM> of the clip <NUM> is formed at a proximal end <NUM> of the clip <NUM>. While the illustrated retention structure <NUM> is integrally formed with the clip <NUM>, the two could be separately formed and secured together in any suitable manner. The integrated construction, however, provides improved manufacturability and a more durable finished product.

The retention structure <NUM> comprises a plurality of posts <NUM> that define a plurality of slots <NUM>. Preferably, the posts <NUM> are spaced about a peripheral surface <NUM> that defines an opening <NUM> at the proximal end of the clip <NUM>. More preferably, the posts <NUM> are substantially equally spaced about the peripheral surface <NUM>. Even more preferably, the posts <NUM> are spaced about the peripheral surface <NUM> such that a ratio of approximately <NUM>:<NUM> is defined between the posts <NUM> and the intervening slots <NUM>. The <NUM>:<NUM> ratio has been found to maximize a strength of connection between the seal <NUM> and the clip <NUM>.

With continued reference to <FIG> and <FIG>, the retention structure <NUM> preferably comprises at least one distal surface <NUM> and at least one proximal surface <NUM> that are generally parallel to each other. In the illustrated configuration, the at least one distal surface <NUM> comprises a ring-like surface that encircles the proximal end <NUM> of the clip <NUM> while the at least one proximal surface <NUM> comprises a plurality of ends of the posts <NUM>. The parallel surfaces <NUM>, <NUM> help to minimize compression and resulting distortion from the clamp forces experienced during the overmoulding process.

Moreover, as shown in <FIG> and <FIG>, the slots <NUM> generally are enclosed by a ring <NUM>. In the illustrated configuration, the ring <NUM> encircles an outside of the posts <NUM> at the distal end of the posts <NUM>. Other configurations also may be possible. The illustrated construction, however, provides a simple to manufacture construction.

With reference to <FIG>, a distal end <NUM> of the clip <NUM> is configured to mount to the frame <NUM>. Preferably, the clip <NUM> is easily mounted to the frame <NUM> and easily removed from the frame <NUM> such that cleaning of the clip <NUM> and attached seal <NUM> can be facilitated. More preferably, the distal portion <NUM> is adapted to seal with a surface of the frame <NUM>. Even more preferably, a distal surface <NUM> is adapted to seal against a surface of the frame <NUM>.

With reference still to <FIG>, the distal portion <NUM> of the clip <NUM> comprises one or more recesses <NUM>. Preferably, the recesses <NUM> also are designed to seal against the frame <NUM>. In particular, the low profile frame <NUM> comprises one or more protrusions <NUM> that extend rearward toward the clip <NUM>. To provide a close fit and to reduce the profile of the assembly <NUM>, the recesses <NUM> in the clip <NUM> advantageously accommodate these protrusions.

With reference to <FIG> and <FIG>, the frame <NUM> and the clip <NUM> preferably connect together in an airtight or sealed relationship. In the illustrated configuration, the frame <NUM> comprises a mounting boss <NUM> that extends toward the clip <NUM>. The mounting boss <NUM> comprises an outer surface <NUM> over which an inner surface <NUM> of the distal end <NUM> of the clip <NUM> slides. Preferably, the connection between the boss <NUM> and the distal end <NUM> of the clip <NUM> is a taper fit. More preferably, the connection comprises a <NUM>:<NUM> medical taper, which provides a sealing surface to minimize leakage between the two components. Even more preferably, the taper connection comprises an interference fit with <NUM> of travel when measured from a rear face <NUM> of the frame <NUM> to the distal surface <NUM> of the clip <NUM>. While the outer surface <NUM> of the illustrated boss <NUM> and the inner surface <NUM> of the illustrated distal end <NUM> are generally cylindrical, other shapes are possible.

With reference to <FIG>, the alternative interface assembly <NUM> includes a modification of the removable mounting arrangement between the clip <NUM> and the frame <NUM>. In particular, the mounting boss <NUM> comprises a wall portion that is intermittent or non-continuous around its circumference. Preferably, a proximal end (i.e., closest to the user) includes at least one and preferably a plurality of recesses or notches <NUM> that extend toward a distal end of the mounting boss <NUM> to facilitate the connection of the clip <NUM> to the frame <NUM>. In particular, the notches <NUM> allow the wall portions of the boss <NUM> in between the notches <NUM> to flex inwardly to effectively reduce the diameter of the mounting boss <NUM> during assembly of the clip <NUM> to the frame <NUM>. In the illustrated arrangement, the notches <NUM> are generally or substantially triangular in shape and four notches <NUM> are provided. However, other shapes (e.g., generally or substantially rectangular, square, trapezoidal, semicircular) and numbers (e.g., <NUM>, <NUM>, <NUM>, <NUM> or more) of notches <NUM> can be used. In addition, preferably the notches <NUM> are spaced unevenly around the circumference of the mounting boss <NUM>. In the illustrated arrangement, the notches <NUM> are arranged in an upper pair and a lower pair in which the circumferential distances between the individual notches <NUM> of the upper and lower pairs are less than the circumferential distances between a notch <NUM> of the upper pair and the adjacent notch <NUM> of the lower pair. Preferably, in other respects, the mounting boss <NUM> of the interface assembly <NUM> of <FIG> is similar to the mounting boss <NUM> of the interface assembly <NUM> of <FIG>, including the taper fit, for example.

The clip <NUM> and frame <NUM> of <FIG> preferably also includes an interference or interlocking arrangement <NUM> that assists in maintaining the connection between the clip <NUM> and the frame <NUM> and/or increases the force required to separate the clip <NUM> from the frame <NUM>. Such an arrangement desirably reduces the likelihood of unintentional or undesired separation of the clip <NUM> and frame <NUM>. Preferably, one of the clip <NUM> and frame <NUM> comprises at least one protrusion and the other of the clip <NUM> and frame <NUM> comprises at least one recess sized and shaped to accommodate the protrusion. In the illustrated arrangement, the clip <NUM> includes a pair of protrusions <NUM> and the frame <NUM> includes a complementary pair of recesses <NUM>; however, this arrangement could also be reversed. Preferably, the protrusions <NUM> are located on the top and bottom of the inner surface <NUM> of the distal end <NUM> of the clip <NUM> and the recesses <NUM> are located on the top and bottom of the outer surface <NUM> of the mounting boss <NUM> of the frame <NUM>. In the illustrated arrangement, the protrusions <NUM> and recesses <NUM> are diametrically opposed from one another and each is elongated in a circumferential direction of the respective surfaces <NUM> and <NUM> to maximize the length of the interfering or interlocking surfaces tending to inhibit separation of the frame <NUM> and clip <NUM> and minimize the length in the axial direction.

Preferably, the frame <NUM> of the interface assembly <NUM> of <FIG> includes at least one recess <NUM> that, in use, accommodates the distal portion <NUM> of the clip <NUM>. In the illustrated arrangement, the frame <NUM> includes a pair of recesses <NUM> that are positioned on opposing sides of the mounting boss <NUM> and interact with the clip <NUM> to inhibit or prevent rotation of the clip <NUM> relative to the frame <NUM>. Preferably, lower ends of the recesses <NUM> are positioned close to the mounting boss <NUM> and upper ends of the recesses <NUM> extend laterally outward away from the mounting boss <NUM>. In comparison to the clip <NUM> of <FIG>, at least a portion of a circumference of the distal portion <NUM> of the clip <NUM> of <FIG> has a smaller wall thickness. The clip <NUM> of <FIG> transitions to a larger wall thickness portion at a shoulder <NUM>, which defines a distally-facing surface <NUM>. Preferably, the surface <NUM> contacts an end surface <NUM> of the recesses <NUM> in addition to the distal surface <NUM> contacting the frame <NUM>, as illustrated in <FIG>, to assist in creating a seal between the clip <NUM> and the frame <NUM>. In addition, the contact between the surface <NUM> and the end surface <NUM> can define a completely connected position between the clip <NUM> and the frame <NUM>. The shoulders <NUM> can be defined by the recesses <NUM> of the clip <NUM> and, thus, can be coextensive with the recesses <NUM>. Engagement of the recesses <NUM> and the recesses <NUM> can inhibit or prevent rotation of the clip <NUM> relative to the frame <NUM>. In other arrangements, the shoulders <NUM> could circumscribe a greater distance than the recesses <NUM> or a single shoulder <NUM> could circumscribe the entire distal portion <NUM>.

With reference to <FIG> and <FIG>, the boss <NUM> preferably surrounds an inner surface <NUM> that defines a socket for a ball connection <NUM> to the connector <NUM>. In the illustrated configuration, the connector <NUM> generally comprises an elbow <NUM> and a swivel <NUM>. The swivel <NUM> can be used to connect to the inspiratory conduit <NUM> or other breathing tube. Preferably, the elbow <NUM> is connected to the frame <NUM> with the joint defined by the ball <NUM> and the socket <NUM> while the swivel <NUM> is connected to the elbow with a cantilevered bump configuration <NUM>.

The joint defined by the ball <NUM> and the socket <NUM> preferably enables a limited range of pivotal movement. In some configurations, the ball <NUM> can pivot up to about <NUM> degrees relative to the socket <NUM>. Other ranges of pivotal movement also can be defined if desired.

In the illustrated configuration, the ball <NUM> is pressed into the socket <NUM> of the frame <NUM> from the side of the frame <NUM> having the rear face <NUM>. In other words, the elbow <NUM> is fed through the socket <NUM> and the ball <NUM> is pressed into engagement with the socket <NUM>. In such a configuration, the elbow <NUM> is unlikely to be easily disassembled from the frame <NUM> by the user.

On the other hand, the swivel <NUM> is designed to be easily removed from the elbow <NUM>. Preferably, the swivel <NUM> is fully rotatable about its axis relative to the elbow <NUM> and the swivel <NUM> can be removed axially from the elbow <NUM> with as little as about <NUM> N of force. Moreover, the connection between the elbow <NUM> and the swivel <NUM> preferably is designed to reduce leakage at the connection. In the illustrated configuration, leakage is maintained at less than about <NUM> to about <NUM>/min at <NUM> H<NUM><NUM>.

With reference to <FIG>, a distal end <NUM> of the elbow <NUM> preferably comprises two or more cut out regions or recesses <NUM>. The recesses <NUM> can have any suitable shape and, in the illustrated configuration, the recesses <NUM> comprise a semicircular configuration that extends upward into the distal end <NUM> of the elbow <NUM>. The distal end <NUM> of the elbow <NUM> also comprises at least one bump <NUM>, and preferably two or more bumps <NUM>. Preferably, each of the bumps <NUM> extends around an arc of about <NUM> degrees. More preferably, each of the bumps <NUM> is generally centered between two recesses <NUM> and each of the bumps <NUM> extends about <NUM> degrees around an outer surface of the distal end <NUM> of the elbow <NUM>.

The swivel <NUM> preferably is generally cylindrical in configuration. As shown in <FIG>, the swivel <NUM> has an inwardly extending ridge <NUM>. The ridge <NUM> preferably encircles the entire inner surface. In some configurations, the ridge <NUM> can be interrupted. Preferably, however, the ridge <NUM> does not have any interruptions large enough to accommodate the entire bump <NUM> such that the ridge <NUM> and the bump <NUM> can cooperate to keep the swivel <NUM> mounted over the distal end <NUM> of the elbow <NUM>. When assembling the swivel <NUM> to the elbow <NUM>, the recesses <NUM> allow the bumps <NUM> to deflect inward such that the bumps <NUM> can slide over the ridge <NUM> and then snap back outward to secure the bumps <NUM> under the ridge <NUM>. For this reason, the distance from a shoulder <NUM> (see <FIG>) to the top of the bump <NUM> (shown as X in <FIG>) is substantially equal to or slightly larger than a distance from a proximal end <NUM> of the swivel (see <FIG>) to the bottom edge of the ridge <NUM>.

With reference now to <FIG>, the elbow <NUM> preferably comprises a plurality of integrally formed exhaust holes <NUM>. While the exhaust holes <NUM> could be formed on a separate insert that is secured to the elbow <NUM>, integrally forming the exhaust holes <NUM> provides a cleaner aesthetic appearance and provides simplified assembly of the interface assembly <NUM>. The exhaust holes preferably are formed on a surface of the elbow <NUM> that is on an outside of the turn from the proximal end, which has the ball <NUM>, toward the distal end <NUM>. Other configurations are possible.

With reference to <FIG>, the exhaust holes <NUM> preferably comprise a two part configuration. A proximal end <NUM> of one or more of the exhaust holes <NUM> forms a conical shaped depression into an inner surface <NUM>. In other words, the proximal end <NUM> of one or more of the exhaust holes <NUM> comprises a countersink-shaped surface. A distal end <NUM> of one or more of the exhaust holes <NUM> comprises a trumpet-shaped surface. In other words, the distal end of one or more of the exhaust holes <NUM> comprises a part of an hourglass shape. Preferably, the conical shape of the proximal end <NUM> and the trumpet shape of the distal end <NUM> are generally axially aligned and feature a smooth transition between the two shapes. More preferably, all or substantially all of the exhaust holes <NUM> have this configuration. Even more preferably, the axial centerlines of all or substantially all of the exhaust holes <NUM> are generally parallel to each other.

With continued reference to <FIG>, the proximal ends <NUM> of the exhaust holes <NUM> preferably define a conical surface that, when viewed in cross section, are substantially parallel to an axial centerline CL of the proximal end of the elbow. In other words, the axial centerline CL generally correlates to a direction of insertion and removal of a die or insert during manufacture. More preferably, when viewed in cross-section, the proximal ends <NUM> of the exhaust holes have at least one sidewall (when viewed in section) that, when viewed in section, will extend generally parallel to (see reference line PL) or extend generally skewed relative to parallel such that the surface extends away from parallel in moving in a proximal direction (i.e., as the proximal end <NUM> expands). In this manner, the proximal ends <NUM> of all or a substantial portion of the exhaust holes <NUM> can be formed from a single insert while allowing the insert to be easily withdraw. In some configurations, the insert or die can be withdrawn through the distal end <NUM> of the elbow and the exhaust holes <NUM> have surfaces that are suitably configured for such a direction of insertion and removal of the insert.

Preferably, the wall thickness (i.e., a distance between the inner surface <NUM> and the outer surface <NUM>) is approximately <NUM>. In such a configuration, the proximal end <NUM> (i.e., the conical portion in <FIG>) is approximately <NUM> while the distal end <NUM> (i.e., the trumpet portion in <FIG>) is approximately <NUM>. Other dimensions and configurations are possible. The illustrated configuration has been found to suitably reduce a noise level associated with the air stream exiting the exhaust holes <NUM>.

With reference again to <FIG>, one or more headgear clips <NUM> are shown attached to the frame <NUM>. In the illustrated configuration, two headgear clips <NUM> are secured to the frame <NUM>. The frame <NUM> generally comprises an ear <NUM> that is associated with each headgear clip <NUM>. The ears <NUM> preferably extend generally laterally outward from the inner surface <NUM> that defines the socket for the elbow <NUM>.

As illustrated in <FIG>, each of the ears <NUM> includes a post <NUM> while each of the clips <NUM> includes a hook <NUM>. The hook <NUM> and the post <NUM> provide an easily connectable and disconnectable configuration. Preferably, the clips <NUM> are symmetrical such that a single clip can be used on both the left and the right sides of the frame <NUM>.

In some configurations, a slight interference can be provided between the hook <NUM> and the post <NUM> such that the hook <NUM> is less likely to inadvertently disengage during use. In some configurations, the hook <NUM> and the post <NUM> can be shaped such that disengagement is easier with the hook <NUM> in certain angular orientations about the post <NUM> (e.g., pivoting the hook <NUM> about the post <NUM> and away from the seal <NUM> can allow easier separation due to a profile of the post <NUM>). Moreover, because the hook <NUM> is capable of pivoting relative to the post <NUM>, the angular orientation of the clip <NUM> relative to the frame <NUM> can be varied such that differing shapes of heads can be easily accommodated.

Each clip <NUM> includes a slot <NUM> defined trough a main body <NUM> of the clip <NUM>. The slot <NUM> is sized and configured to accommodate a lower strap <NUM> of a headgear assembly <NUM>. Preferably, the lower strap <NUM> loops through the slot <NUM> and folds back over itself. More preferably, the lower strap <NUM> includes a hook and loop fastener portion such that the lower strap <NUM> loops through the slot <NUM>, folds back over itself and is secured to itself. Other configurations also can be used.

The headgear assembly <NUM> also comprises a pair of top straps <NUM> and a pair of upper straps <NUM>. The top straps <NUM>, the upper straps <NUM> and the bottom straps <NUM> preferably meet at a central body <NUM>. Moreover, each of the straps <NUM>, <NUM>, <NUM> preferably terminates with a tab <NUM> that can form a portion of a hook and loop fastener. The tabs <NUM> can be ultrasonically welded onto the ends of the straps <NUM>, <NUM>, <NUM>.

Together, the straps <NUM>, <NUM>, <NUM> and the body <NUM> define the headgear assembly <NUM>. In some configurations, the headgear assembly comprises a three-layer construction, which includes layers formed of Lycra, foam and UBL (unbroken loop) materials. Advantageously, the UBL material provides a surface onto which the tabs <NUM> can stick. In some configurations, the thickness of the three-layer construction is about <NUM>.

The top straps <NUM> can be connected together with a buckle that will sit generally at the top of the head. When combined together with the buckle, the top straps <NUM> generally define a crown strap. The upper straps <NUM> loop through slots <NUM> (see <FIG>) formed in a t-piece section of the frame <NUM> and the lower straps <NUM> loop through the clips <NUM> as described above. In some configurations, the slots <NUM> in the t-piece section of the frame <NUM> have a break in the material defining the slots <NUM> such that the loop defined by the upper straps <NUM> can be attached and detached to the frame <NUM> without separating the tab <NUM> from the portion of the strap <NUM> to which the tab <NUM> is attached with the hook and loop fastener.

In the alternative interface arrangement <NUM> of <FIG>, the slots <NUM> define openings <NUM> at bottom ends of the slots <NUM> and have closed ends <NUM> at the top ends thereof. In particular, a central portion <NUM> of the frame <NUM> extends along inner sides of the slots <NUM> and transitions into an upper portion <NUM> that defines the closed ends <NUM> of the slots <NUM>. Outer portions <NUM> extend along outer sides of the slots <NUM> and terminate in inwardly-extending tabs <NUM> that extend toward the central portion <NUM>, but stop short thereof to define the openings <NUM> of the slots <NUM>. The upper closed ends <NUM> prevent the upper straps <NUM> from becoming disconnected from the frame <NUM> in an upward direction and the tabs <NUM> inhibit unintentional or undesirable disconnection of the upper straps <NUM> from the frame <NUM> in a downward direction.

The body <NUM> preferably is defined as regions that interconnect the various straps <NUM>, <NUM>, <NUM> and the regions that taper to the straps <NUM>, <NUM>, <NUM> to provide reinforcement to the intersections of the straps <NUM>, <NUM>, <NUM>. The body <NUM> can be configured to sit below the Inion point of the skull. Such a positioning on the user decreases movement of the headgear assembly <NUM> when the user turns the head. Moreover, with the straps attached a three dimensional configuration results from generally straight strap configurations. In other words, as shown in <FIG>, the lower straps <NUM> extend in a substantially straight manner from the body <NUM>. As such, a generally central line LS extends along each of the lower straps <NUM>. Similarly, as shown in <FIG>, the upper straps <NUM> also extend in a substantially straight manner from the body <NUM>. As such, a generally central line US extends along both the upper straps <NUM>. In the illustrated configuration, the central line US do not intersect the entire body <NUM>. In other words, the body has a portion that is offset from, and not intersected by, the central line US. In some configurations, the generally central lines LS are positioned at an angle relative to the generally central line US. Preferably, the angle is between about <NUM> degrees and about <NUM> degrees.

Claim 1:
A clip member (<NUM>) for an interface assembly, the clip member (<NUM>) comprising:
an opening (<NUM>) defined by a peripheral surface (<NUM>) at a proximal end (<NUM>);
a retention structure (<NUM>) formed at the proximal end (<NUM>), the retention structure (<NUM>) comprising a plurality of posts (<NUM>) spaced about the peripheral surface (<NUM>), at least one proximal surface (<NUM>) of the retention structure (<NUM>) comprising ends of the plurality of posts (<NUM>), the plurality of posts extending away from a distal end of the clip member (<NUM>) and defining a plurality of slots (<NUM>); and
a ring (<NUM>) that encircles an outside of a distal end of the plurality of posts (<NUM>),
wherein the retention structure (<NUM>) is configured to allow secure overmoulding of a separate seal member (<NUM>) onto the clip member (<NUM>),
wherein the distal end (<NUM>) of the clip member (<NUM>) is configured to mount to and be removed from a frame (<NUM>), the distal end (<NUM>) of the clip member (<NUM>) comprising a distal surface (<NUM>) that is adapted to seal against a surface of the frame (<NUM>), and
wherein the clip member (<NUM>) tapers from a larger footprint at the proximal end (<NUM>) to a smaller footprint distal thereto.