NZ754381B2 - A foam-based interfacing structure method and apparatus - Google Patents
A foam-based interfacing structure method and apparatus Download PDFInfo
- Publication number
- NZ754381B2 NZ754381B2 NZ754381A NZ75438109A NZ754381B2 NZ 754381 B2 NZ754381 B2 NZ 754381B2 NZ 754381 A NZ754381 A NZ 754381A NZ 75438109 A NZ75438109 A NZ 75438109A NZ 754381 B2 NZ754381 B2 NZ 754381B2
- Authority
- NZ
- New Zealand
- Prior art keywords
- cushioning component
- connection portion
- component
- interfacing structure
- foam
- Prior art date
Links
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Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
- A61M16/06—Respiratory or anaesthetic masks
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
- A61M16/06—Respiratory or anaesthetic masks
- A61M16/0605—Means for improving the adaptation of the mask to the patient
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
- A61M16/06—Respiratory or anaesthetic masks
- A61M16/0605—Means for improving the adaptation of the mask to the patient
- A61M16/0616—Means for improving the adaptation of the mask to the patient with face sealing means comprising a flap or membrane projecting inwards, such that sealing increases with increasing inhalation gas pressure
- A61M16/0622—Means for improving the adaptation of the mask to the patient with face sealing means comprising a flap or membrane projecting inwards, such that sealing increases with increasing inhalation gas pressure having an underlying cushion
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
- A61M16/06—Respiratory or anaesthetic masks
- A61M16/0605—Means for improving the adaptation of the mask to the patient
- A61M16/0633—Means for improving the adaptation of the mask to the patient with forehead support
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
- A61M16/06—Respiratory or anaesthetic masks
- A61M16/0683—Holding devices therefor
- A61M16/0688—Holding devices therefor by means of an adhesive
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M2207/00—Methods of manufacture, assembly or production
- A61M2207/10—Device therefor
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M2209/00—Ancillary equipment
- A61M2209/02—Equipment for testing the apparatus
Abstract
respiratory mask to provide a supply of pressurized air to the entrance of the airways of a patient for treatment of sleep disordered breathing including a frame, and an interfacing structure comprising a connection portion (3234) and a cushioning component (3232). The connection portion is of reduced hardness or increased flexibility compared to the frame. The cushioning component is at least partially constructed from a foam material and is configured to directly engage and form a seal with a region of the patient’s face in the vicinity of an entrance to the patient’s airways. An interior of the interfacing structure at least partially forms a cavity to receive at least a portion of the patient’s nose in use. A connection portion attachment surface (3500) of the connection portion is joined to a cushioning component attachment surface of the cushioning component. At least one of the following parameters of the interfacing structure varies around a perimeter of the interfacing structure and at least contributes to a roll-in effect of the cushioning component: 1) an amount of offset between an inner edge of the connection portion attachment surface and an inner edge of the cushioning component attachment surface; 2) a cross-sectional profile of the connection portion; 3) an offset of an apex (3600) of a cross-sectional profile of the cushioning component; and 4) an angle of the connection portion attachment surface in a radial direction of the interfacing structure. uced hardness or increased flexibility compared to the frame. The cushioning component is at least partially constructed from a foam material and is configured to directly engage and form a seal with a region of the patient’s face in the vicinity of an entrance to the patient’s airways. An interior of the interfacing structure at least partially forms a cavity to receive at least a portion of the patient’s nose in use. A connection portion attachment surface (3500) of the connection portion is joined to a cushioning component attachment surface of the cushioning component. At least one of the following parameters of the interfacing structure varies around a perimeter of the interfacing structure and at least contributes to a roll-in effect of the cushioning component: 1) an amount of offset between an inner edge of the connection portion attachment surface and an inner edge of the cushioning component attachment surface; 2) a cross-sectional profile of the connection portion; 3) an offset of an apex (3600) of a cross-sectional profile of the cushioning component; and 4) an angle of the connection portion attachment surface in a radial direction of the interfacing structure.
Description
James & Wells Ref: 505071DIV1/60
A FOAM-BASED INTERFACING STRUCTURE METHOD AND APPARATUS
CROSS-REFERENCE TO APPLICATION
This application claims the benefit of Australian Provisional Patent
Application Nos. AU 2008904769, filed September 12, 2008, and AU 2008904778, filed
September 15, 2008, each of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to an interface between a human and a piece of
equipment, for example respiratory devices that include a foam-based interfacing structure.
BACKGROUND OF THE INVENTION
In a number of fields, such as respiratory therapy, apparatus for delivery of
therapy includes a rigid component and a soft, cushioning component positioned between a
patient and the rigid component.
In the case of a respiratory device, the rigid component may be a mask frame
defining a nose and/or mouth-receiving chamber. The mask frame may include a flange
around its periphery or other connecting means.. The cushioning component may be glued or
otherwise coupled to the flange or connecting means.
The cushioning component may form aa seal with the skin of the patient in
some forms of respiratory therapy. In other devices, for example headphones, it may not be
necessary for aa seal to be formed.
SUMMARY OF THE INVENTION
A first aspect of the invention is to provide a mask assembly with a foam
interfacing structure.
Another aspect of the invention is to provide a mask assembly with a foam
interfacing structure where at least a part of the foam (e.g., an unskinned part of the foam) is
in direct contact with the skin of the mask user.
1524123
James & Wells Ref: 505071DIV1/60
Another aspect of the invention is to provide a mask assembly with a foam
interfacing structure where the foam is unskinned and has a cellular structure of the foam in
direct contact with the skin of the mask user.
Another aspect of the invention is to provide a mask assembly with a
removable foam interfacing structure.
Another aspect of the invention is to provide a mask assembly with at least
two different types of removably replaceable interfacing structures.
Another aspect of the invention is to include a softer interfacing structure
having portion adapted for engagement with a more rigid component.
Another aspect of the invention is to provide a respiratory mask assembly
including a frame and an interfacing structure wherein the interfacing structure includes a
foam-based cushion component and a clip portion adapted for removable engagement with
the frame portion.
Another aspect of the invention is to provide a support structure for a
cushioning component wherein the support structure supports the cushioning element on one
side and allows movement on another side.
Another aspect of the invention relates to a cushion for a respiratory mask
including a clip portion and a cushioning component wherein the cushioning component is
constructed from a foam material and the clip portion is narrower than the cushioning
component.
Another aspect of the invention relates to a respiratory mask assembly
including a frame having a channel and an interfacing structure including a clip portion
adapted for interference seal and retention in the channel. The interfacing structure includes
a cushion component constructed from foam and having a wider width than the clip portion.
Another aspect is a foam-based cushioning component preferably having a
first cross-section in a nasal bridge region, a second cross-section in a lip region and a third
cross-section in the cheek region.
Another aspect is a method of manufacturing a cushioning component, e.g.,
die cutting and/or machining, etc.
Another aspect is a method of insert molding a clip component to a cushioning
component to form an interfacing structure.
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James & Wells Ref: 505071DIV1/60
Another aspect is a cushioning component for use with a mask, wherein the
cushioning component is constructed of foam material. A patient contacting surface, that is
adapted to contact a patient, in use, may have a rounded cross sectional profile and a base
surface opposed to the patient contacting surface.
Another aspect is a removable interfacing structure for use with a mask
including a cushioning component constructed of foam material wherein a patient contacting
surface that is adapted to contact a patient, in use, has a rounded cross sectional profile and a
base surface opposed to the patient contacting surface is joined to a clip portion, and wherein
the clip portion is adapted to be removably joined to a frame of the mask.
Another aspect is a mask including a removable interfacing structure and a
frame, wherein the interfacing structure includes a clip portion and a cushioning component
constructed of foam material having a patient contacting surface that is adapted to contact a
patient, in use, has a rounded cross sectional profile and a base surface opposed to the patient
contacting surface is joined to the clip portion, and wherein the clip portion is adapted to be
removably joined to a frame of the mask.
Another aspect is a mask including a frame and an interfacing structure,
wherein the interfacing structure includes a clip portion joined to cushioning component, and
wherein the frame is more rigid than the clip portion and the clip portion is more rigid than
the cushioning portion.
Another aspect is a cushioning component for use with a mask, wherein at
least a portion of the cross section of the cushioning component includes an inner side
defined by the side facing the centre of the mask, an outer side defined by a side facing away
from the centre of the mask and a base side facing the frame or clip portion, wherein the
length of outer side is greater than the inner side.
Another aspect is an interfacing structure for a mask including a clip portion
joined to a cushioning component, wherein an upper surface of the clip portion is joined to a
base surface of the cushioning component and wherein at least a portion of the upper surface
is angled to provide a moment force on cushioning component, when force is applied into the
cushioning component.
Another aspect is an interfacing structure for a mask including a clip portion
joined to a cushioning component, wherein an upper surface of the clip portion is joined to a
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James & Wells Ref: 505071DIV1/60
base surface of the cushioning component and wherein the cross sectional width of the clip
portion is less than the cross sectional width of the cushioning component.
Another aspect is a cushioning component for use with a mask, wherein at
least a portion of the cross section of the cushioning component includes an inner side
defined by the side facing the centre of the mask, an outer side defined by a side facing away
from the centre of the mask and a base side facing the frame or clip portion, wherein the outer
side further includes at least an upper and a lower portion, wherein the upper portion is
positioned at a reduced angle in comparison to the lower portion.
Another aspect is a nasal mask including a frame removably connected to an
interfacing structure, wherein the interfacing structure includes a cushioning component
constructed of foam material, and wherein the height of the interfacing structure is reduced in
relation to region that is adapted to contact the upper lip region of a patient’s face.
One aspect of the present technology relates to a respiratory mask including a
frame, a foam cushion and a substructure. The mask includes a nose receiving cavity. The
cushion includes at least two sides: an inner side wall, which may be a wall at least partially
facing the cavity; and an outer side wall. The foam cushion is soft and conforming. The
substructure is constructed from a more rigid material. The foam cushion is adapted to form a
seal with at least one region of a face of a patient. In use the foam cushion is supported by the
substructure. A connecting surface of the substructure is defined. A patient side of the foam
cushion is defined. A non-patient side of the cushion is defined. In use the non-patient side of
the cushion is arranged adjacent the connecting surface of the substructure. In one form the
foam cushion is glued to the substructure. In another form the foam cushion is insert moulded
with the substructure. A first region of the face is defined as a corner of the mouth of the
patient. A second region of the face is defined as a chin region, or alternatively a lip region of
the face of the patient. An interior region of the cushion is defined as the region or cavity into
which a nose of a patient is inserted in use.
In one form, a part of the connecting surface in use adjacent the first region is
structured in to direct a corresponding portion of the foam cushion in an inward direction
towards the interior region of the cushion in the first region in use. The cross-section of the
cushion defines a radial axis and a longitudinal axis is normal to said radial axis. Preferably,
at least a portion of the foam cushion is adapted to rotate towards the centre of the mask
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James & Wells Ref: 505071DIV1/60
about said longitudinal axis when pressure is applied into the cushion by the patient’s face
and wherein at least a portion of the outer side wall of said cushion is adapted to form a seal
against the face of a patient.
Wherein portions of the cushion rotate or roll inwards towards the centre of
the mask. The feature of rolling or rotating inwards may prevent or limits the possibility of
the seal “blowing out” when air pressure is applied to the mask cavity. “Blowing out” is
defined by the seal between the cushion and the patient’s face breaking due to pressure
exerted by air pressure lifting the cushion from a sealing relationship with the face.
In one form, a part of the connecting surface in use adjacent the second region
is structured to direct the foam in an outward direction away from the interior region of the
cushion in the second region in use. The cross-section of the cushion defines a radial axis and
a longitudinal axis is normal to said radial axis. Preferably, at least a portion of the foam
cushion is adapted to rotate away from the centre of the mask about said longitudinal axis
when pressure is applied into the cushion by the patient’s face and wherein at least a portion
of the outer side wall of said cushion is adapted to form a seal against the face of a patient.
Preferably, further portions of the cushion may rotate inwards or outwards
relative to the centre of the mask in positions defined as being proximal to the patient’s chin.
In regions or portions of the cushion that can rotate or roll inwards and outwards, this rotation
may allow for seal to accommodate different sizes of chin and/or accommodate moderate
amounts of mouth or jaw movement that may otherwise destruct the seal formed between the
mask and the patient’s face.
Another aspect of the present technology is a foam cushion for a respiratory
mask wherein the cushion includes a face-contacting portion arranged in use to be adjacent
the face of the patient.
Preferably in at least some regions of the face contacting portion, a cross
section of the cushion tapers from a wider cross-section to a narrower cross-section closer to
the face. The tapered portion defines an inside surface adjacent an interior of the cushion and
an outside surface. The inside surface and the outside surface may be adjacent, in another
form they may be non-adjacent. The inside and outside surfaces may be arranged at an acute
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James & Wells Ref: 505071DIV1/60
angle with respect to one another. In one form in cross-section the outside surface is longer
than the inside surface in certain regions of the cushion, preferably in the nasal bridge region,
or in the cheek region, or more preferably in both. In one form the inside and outside surfaces
have the same length in a chin region. In one form in a lip region the inside surface is longer
than the outside surface in cross-section.
In one form, the cushion is structured to at least partially form a seal on an
outside surface of a face in a chin region of the cushion. We have found that a tapered sealing
portion may improve the seal.
Other aspects are directed to methods for manufacturing the foam cushioning
elements described above.
Other aspects, features, and advantages of this invention will become apparent
from the following detailed description when taken in conjunction with the accompanying
drawings, which are a part of this disclosure and which illustrate, by way of example,
principles of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings facilitate an understanding of the various
embodiments of this invention. In such drawings:
Fig. 1 shows a side view of a mask assembly including a foam interfacing
structure according to an embodiment of the invention;
Fig. 2 shows a schematic diagram of a channel of a portion of a mask frame
and a clip portion of an interfacing structure retained by an interference fit according to an
embodiment of the invention;
Figs. 3a, 3b, and 3c show a range of rib engagement fitting arrangements
between a mask frame and a clip portion of an interfacing structure according to
embodiments of the invention;
Fig. 4a shows a patient contacting side of an interfacing structure according to
an embodiment of the invention;
Fig. 4b shows a bottom view of the interfacing structure of Fig. 4a;
Fig. 4c shows a top view of the interfacing structure of Fig. 4a;
Fig. 4d shows a side view of the interfacing structure of Fig. 4a;
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James & Wells Ref: 505071DIV1/60
Fig. 4e shows a frame contacting side of the interfacing structure of Fig. 4a;
Fig. 4f shows a patient contacting side isometric view of the interfacing
structure of Fig. 4a;
Fig. 4g shows a frame contacting side isometric view of the interfacing
structure of Fig. 4a;
Fig. 5a is a plan view showing a die cut interfacing structure wherein the clip
portion includes a slot for engagement with the frame according to an embodiment of the
invention;
Fig. 5b is an isometric view of the interfacing structure shown in Fig. 5a;
Fig. 5c is an assembly view of the interfacing structure shown in Fig. 5a with a
mask frame;
Fig. 6a shows a cross-section from a prior art nasal mask with foam cushion;
Fig. 6b shows a detail in the nasal bridge region of the mask of Fig. 6a;
Fig. 7a shows an elevation view detail from the frame side of the interfacing
structure shown in Fig. 4e;
Fig. 7b is a cross-section along line 7b-7b of Fig. 7a;
Fig. 7c is a cross-sectional view showing the interfacing structure of Figs. 7a
and 7b in use;
Fig. 8 is a cross-sectional view showing the assembly of the interfacing
structure of Figs. 7a and 7b and a frame according to an embodiment of the invention;
Figs. 9a to 9d show various views of a foam-based interfacing structure
according to an embodiment of the present invention;
Figs. 10a to 10c show various views of a foam-based interfacing structure
according to another embodiment of the present invention;
Figs. 11a to 11c show various views of a foam-based interfacing structure
according to another embodiment of the present invention;
Figs. 12a to 12f show various views of a foam-based interfacing structure
according to another embodiment of the present invention;
Fig. 13 is a perspective view of a clip portion according to an embodiment of
the present invention;
Figs. 14a to 14f show various views of a foam-based interfacing structure
according to an embodiment of the present invention;
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James & Wells Ref: 505071DIV1/60
Figs. 15a to 15e show various views of a cushion-to-frame component of the
interfacing structure shown in Figs. 14a to 14f;
Figs. 16a to 16i show various views of the cushioning component of the
interfacing structure shown in Figs. 14a to 14f;
Figs. 17a to 17h illustrate a tool and manufacturing process for manufacturing
an interfacing structure according to an embodiment of the present invention;
Figs. 18a to 18c show various views of a tool for molding a clip portion
according to an embodiment of the present invention;
Fig. 19 is a front view of a further embodiment of a full face cushioning
component;
Figs. 20-25 depict various cross-sectional views of the embodiment shown in
Fig. 19;
Fig. 26 is a front view of a further embodiment showing an interfacing
structure for use with a full face mask including a cushioning component and clip portion;
Figs. 27-32 depict various cross-sectional views of the embodiment shown in
Fig. 26. Fig. 29 defines a horizontal plane of connection between the cushion and the clip
portion.In Figures 30 to 32 the plane of connection is at an angle with respect to the
horizontal, In Fig. 30 the plane of connection is at a downward angle when moving from the
outside to the inside of the interfacing portion, in Fig. 32 the plane of connection is at an
upward angle when moving from the outside to the inside of the interfacing portion.
Fig. 33 is a perspective view of full face interfacing structure including a
cushioning component and clip portion;
Fig. 34 is a side view of the embodiment shown in Fig. 33;
Fig. 35 is a top view of the embodiment shown in Fig. 33;
Fig. 36 is a bottom view of the embodiment shown in Fig. 33;
Fig. 37 is a back view of the embodiment shown in Fig. 33;
Fig. 38 is a front view of the embodiment shown in Fig. 33;
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Fig. 39 is a front view of a further embodiment of a interfacing structure for
use with a nasal mask;
Fig. 40 is a top view of the embodiment shown in Fig. 39;
Fig. 41 is a bottom view of the embodiment shown in Fig. 39;
Fig. 42 is a side view of the embodiment shown in Fig. 39;
Fig. 43 is a back view of the embodiment shown in Fig. 39;
Fig. 44 is a front view of a further embodiment of an interfacing structure for
use with a nasal mask;
Figs. 45-47 depict various cross-sectional views of the embodiment shown in
Fig. 44;
Fig. 48 is a chart showing exemplary material properties for a cushion
component according to an embodiment of the invention;
Fig. 49 is a chart showing exemplary material properties for a clip portion
according to an embodiment of the invention;
Figs. 50-1 to 57-2 illustrate alternative mechanisms for attaching a clip portion
to a frame according to embodiments of the invention;
Figs. 58 and 59 illustrate the rolling effect of a cushioning component
according to an embodiment of the invention;
Figs. 60-1 to 60-8 illustrate different parameters and apparatus for testing air
permeability according to an embodiment of the invention;
Fig. 61 illustrates apparatus for testing hardness according to an embodiment
of the invention;
Figs. 62-1 to 62-2 illustrate different parameters and apparatus for testing
tensile strength according to an embodiment of the invention;
Figs. 63-1 to 63-4 illustrate different parameters and apparatus for testing tear
resistance according to an embodiment of the invention; and
Fig. 64 illustrates apparatus for testing total mask flow according to an
embodiment of the invention.
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DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS
The following description is provided in relation to several embodiments
which may share common characteristics and features. It is to be understood that one or
more features of any one embodiment may be combinable with one or more features of the
other embodiments. In addition, any single feature or combination of features in any of the
embodiments may constitute additional embodiments.
In this specification, the word “comprising” is to be understood in its “open”
sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the
sense of “consisting only of”. A corresponding meaning is to be attributed to the
corresponding words “comprise", "comprised" and "comprises" where they appear.
The term "air" will be taken to include breathable gases, for example air with
supplemental oxygen.
The term “seal” will be taken to mean to reduce the flow of air between the
pressurized interior of the mask and the ambient conditions to a level sufficient to maintain a
therapeutic pressure in the airways to effect treatment. Hence in some cases, there may be an
air tight seal, in other cases there may be a small leak.
1. INTRODUCTION
A mask assembly used to facilitate the delivery of a supply of air or breathable
gas to the entrance of the airways of a patient typically includes a generally soft, conforming
interfacing structure, at least a portion of which is in contact with the patient's face and a
stabilizing structure that positions and retains the interfacing structure in a suitable position
with respect to the patient. The mask assembly typically includes some form of anchor point
to which various components may be connected, or about which they may be arranged. In
this specification, this anchor point will be referred to as the frame.
By way of example, the stabilizing structure of the mask assembly may be
called “headgear” and both the headgear and interfacing structure may be connected to a
frame. In some forms of mask, the boundary lines between the different components may be
blurred. For example, aspects of frame and headgear may be combined.
The interfacing structure may perform two or more functions: (i) a cushioning
function, performed by a cushioning component, and (ii) an interconnection function,
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performed by a cushion-to-frame component or clip portion. Generally, in this specification
the term “clip” or “clip portion” may describe the aforementioned clip portion or a cushion to
frame component for securing the cushioning component to a frame of a mask.
Forming the interfacing structure from two separate elements enables each to
have different properties, such as different densities or air permeabilities as suits their
different roles, as will be described in more detail in the following sections. Furthermore, the
different properties of different materials can act to influence the other component. For
example, a more rigid clip or cushion-to-frame portion can act as a support structure for a
softer cushioning component.
However, in another embodiment, the interfacing structure may be constructed
from a single component with different properties in different regions of the interfacing
structure. Furthermore, the interfacing structure may be formed from more than two
components.
The interfacing structure may be constructed and arranged to apply air or
breathable gas to both the nose and mouth (a “nose & mouth” or “full-face” mask), or to the
just the nose (a “nose” or “nasal” mask), or just the mouth (a “mouth” mask).
The statement “more rigid” may be understood to mean less flexible and/or
stiffer.
2. CUSHION COMPONENT
2.1 Material
In one form, the cushioning component may be made from an unskinned, low
density, permeable foam. In a preferred embodiment, the cushion component is constructed
from a low resilience viscoelastic polyurethane foam. The cushioning component material
may be manufactured from a free rising slabstock foam process. In other embodiments the
material may be manufactured by other processes such as molding or other known processes
used to produce soft and cellular materials. One or more fabrication steps (known as
conversion techniques) may then be applied to the material to partially or completely form
the geometry of the cushion component. These conversion techniques are described herein
and in other related specifications referenced herein. Such a foam material and conversion
techniques are disclosed in PCT Publication Nos. , published January 31,
2008, and , published June 19, 2008, each of which is incorporated herein
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by reference in its entirety. In one form, the cushioning component may be formed in whole
or in part by a known method such as die cutting. Die cutting is disclosed in PCT
Application , filed March 4, 2009. In another form the cushioning
component may be formed in whole or in part by using other methods such as those disclosed
in AU 2008904769 and AU 2008904778.
Most foam material production techniques produce a material that has a
substantially skinned material such that the density of the material at the surface is greater
than the density of the material’s bulk (internal) properties. The utilization of particular
manufacturing techniques, such as foam conversion processes involving cutting, may allow
the production of a unskinned cushioning component such that the bulk properties of the
cellular material are exposed at the surface of the cushioning component, providing a number
of advantages to the design, manufacture and performance of the mask assembly.
The unskinned cushion component provides improved sealing, comfort and fit
range performance, sealing properties sufficient to not require a silicone membrane, and a
unskinned mask assembly that allows utilization of the bulk properties of the unskinned
material, e.g., porosity for breathability, fine cell structure for a comfortable feel.
2.2 Shape
The interfacing structure is preferably constructed and arranged to have a three
dimensional shape defined in part by a locus of points surrounding and complementary to the
entrance to the relevant airways. Furthermore, the interfacing structure has a cross-section
chosen at different points around its perimeter to provide efficacy and comfort by being
suitably shaped to adapt and conform to the face of the user forming a compression-type seal.
In another configuration, a flap-type seal is formed.
The shape of the interfacing structure may be adapted to allow the cushioning
component to provide a better fit and seal against the face of the patient.
In an embodiment, the geometry of the cushion may be at least partly
determined by the geometry of the frame to which it is to be attached. For example, the
general shape of a small size cushion may be different than the general shape of a large size
cushion because the small and large size frames may be different, e.g., the small may be more
stout or wide while the large may be more elongated and thinner.
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2.2.1 Full Face Mask
Figs. 16g to 16i show various cross-sections through one embodiment of the
cushioning component 932 (origin of cross section shown in Fig. 16f). Fig. 19 shows an
alternative embodiment of the present invention with corresponding cross sections in Figs.
-25.
Figs. 33-38 depict a further preferred embodiment of a interfacing structure
wherein the interfacing structure includes a co-molded or otherwise attached cushioning
component and a clip portion
Preferably, the full face masks depicted in this specification may have
cushioning components about 105-110 mm in width (as measured from the outer most edges
of the base surfaces); and a length of between 120-150 mm.
Nasal Bridge Region
As shown in Fig. 16g, the cross section at the nasal bridge region NB is
generally triangular. The cross section at the nasal bridge region NB may also be another
other reasonable shape, such as generally rectangular, oval, octagonal etc. In addition, it is
possible for the cross section at the nasal bridge region to include a shape with generally
rounded or curved corners. The cross section at the nasal bridge region may also be an
irregular shape. Fig. 20 shows an alternative cross section for the nasal bridge region.
There is a radius r1 at the apex 2010 of the cross section, that may be
relatively small or sharp radius at the nasal bridge region NB. For example, radius r1 may be
between 1 to 4 mm. This relatively small or sharp radius at radius r1 provides the advantage
that the cushioning component is kept away from the patient's eyes, especially when the
cushioning component is compressed and inflated with air pressure in use. The relatively
small or sharp radius at radius r1 may also enable minimal contact of the mask with the
patient’s skin, so as to make the mask feel more comfortable and less obtrusive.
As best shown in Fig. 20, apex 2010 of the generally triangular cross section
may be skewed or offset. The apexes or the corners of the generally triangular cross sectional
may be rounded to promote a better fit with the patient and/or a better seal. This offset is
shown on Fig. 20, where apex 2010 and center line 2015 are spaced by distance 2020.
Distance 2020 may be preferably around 1-2mm at the position proximal to the patient’s
nose. The comparable offset in the cushioning component about the portion adapted to cover
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the bottom lip of the patient is preferably 8mm. The comparable offset in the cushioning
component about the portion adapted to cover the cheeks of the patient is preferably 1.25mm.
Fig. 20 demonstrates an offset towards the inner edge of the cushioning component.
Alternatively the apex may be skewed, or over the outer edge of the cushioning component.
Additionally, the generally triangular cross section of the cushioning portion
may also additionally be defined has having three sides: an inner side which faces into the
centre of the mask; an outer side facing away from the centre of the mask and a base surface,
which may be adapted to be joined to a clip portion, at least in part.
The outer side of surface of the cushioning portion is generally adapted to be
longer than the inner surface. This may allow the cushioning component to, in effect, roll,
bend or move inwards. The rolling motion leads to an extension of the sealing surface formed
between the skin of the patient and the cushioning component. As the cushioning component
is depressed, the contact region against the patient’s skin is lengthened from the minimum
contact point which is the apex to at least partially extending along the outer surface or side
of the cushioning component.
For example, the apex of the triangle that contacts the user’s face (Fig. 58)
enables the cushion component 932 to deflect or roll such that if the apex is towards the inner
part of the cushion component, the cushion component will roll inwards and over the clip
portion 934 about hinge point 939. Air pressure AP from the CPAP device (Fig. 59) acts on
the back of the rolled section of the cushion component 932 such that the air pressure forces
the cushion component into sealing engagement on the patient’s face.
The rolling effect or the turning moment force, when the mask is pressed onto
the face, can be also increased or assisted the positioning or shape of the clip portion attached
to the cushioning portion. Preferably, the clip portion 3234 may be joined to the base surface
of the cross section of the cushioning component. More preferably, the clip is mounted
proximal to the outer side of the cushioning component, and provides little or no support
relative to the inner side of the cushioning component. Preferably, the clip portion may not
generally support the inner side of the cushioning component.
Preferably, the clip portion includes a stepped configuration when viewed in
accordance with its cross section. In Figs. 27-32, a preferred clip portion is joined to a
cushioning portion. The stepped configuration is adapted to mate with a corresponding
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groove, slot or recess in the frame to provide aa seal. In this embodiment, the step formation
is oriented towards the outer side of the cushioning component for ease of use by the patient.
Preferably, the clip portion is joined to the cushioning component by an upper
side. The upper side of the clip portion may be shaped to assist with: sealing of the
cushioning component; comfort; and/or the aforementioned rolling effect of the cushioning
component. In Figs. 30-31, the upper side of the clip portion has been angled towards the
centre of the mask by lengthening the outer side of the clip portion relative to the shorter
inner side of the clip portion. This angling of the upper surface of the clip portion is adapted
to aid or assist in the rolling in effect of the cushioning component. Additionally, in the
embodiments shown in Figs. 26-32, the angled upper side of the clip portion has been
included on the lower corners of the mask. For example, as shown in Figs. 30 and 31, the
upper surface of the clip portion is angled to enhance rolling and sealing in lower cheek and
lip regions (e.g., a1 and a2 between about 0-20°). As shown in Fig. 32, the angle of the upper
surface in the chin region (e.g., a3 between about 0-20°) is oriented opposite that in the lower
cheek and lip regions (e.g., the bottom lip region ) (Figs. 30 and 31), e.g., for
manufacturability.
Preferably, the upper corner which is adapted to engage the nasal bridge of the
patient, the upper surface of the clip portion is flat and not angled towards to the centre of the
mask. This is generally because the region around the nose doesn’t require as much “roll” as
the sealing area against the sides of the nose is relatively long compared the regions around or
about the cheeks of the patient. This feature is demonstrated in Figs. 27 and 28.
Preferably, the nasal bridge region also includes a modification to the base
surface, wherein the base surface has been reduced or shortened to thereby reduce the volume
of foam material rolled inwards at the nasal bridge.
Fig. 32 depicts the interfacing structure wherein the upper surface of the clip
surface has been angled outwards relative to the centre of the mask. This reduces the effect of
“roll in” in the predetermined regions including this outwardly disposed angle of the upper
surface. Generally, the outwardly disposed angle of the upper surface is suitable for regions
requiring reduced “roll in” such as around the bottom lip or around the upper lip (in the nasal
mask configurations). Another way to regulate “roll in” is by changing the amount of
overhang of the cushioning component with respect to the clip portion.
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As shown in Fig. 16f, the inner apex 2050 of the cushion has the radius of
curvature of between 3 to 10mm (most preferably 3-5mm). This is similarly shown in Fig. 19,
where the inner apex 2050 of the cushion has the radius of curvature. The size of this radius
may affect the durability, and more specifically the tear strength of this region.
As shown on Figs. 16g and 20, inner edge 2090 may have an angle 2100 from
the base of the cushioning component. Angle 2100 may influence the amount of the
cushioning component that may contact the patient. For example, angle 2100 shown in Fig.
16f may be larger than angle 2100 shown in Fig. 20, such that more of the cushioning
component in Fig. 16f may contact the patient’s face than that of Fig. 20. Preferably, angle
2100 may be about 90-95 degrees. The angle of the outer side or edge meeting the base
surface is preferably between 78-83. Preferably, the angle by which the outer side meets with
the base surface is generally less than the angle formed between the inner side and the base
surface.
The most preferred maximum width of the nose bridge region (as measured
along the base surface) is 22mm and most preferred maximum height of the cushioning
component at the nose bridge position is approximately 24 mm.
Bottom Lip Region
As shown in Fig. 16g, the cross section at the bottom lip region BL may
preferably be generally trapezoidal. The cross section at the bottom lip region BL may also be
another other reasonable shape, such as generally rectangular, oval, octagonal etc. In
addition, it is possible for the cross section at the bottom lip region to include a shape with
generally rounded or curved corners. The cross section at the bottom lip region may also be
an irregular shape. Fig. 25 demonstrates this feature in a cross section for the bottom lip
region.
Preferably, in the embodiment depicted in Fig. 25, the apex 950 is skewed
towards the centre of the mask, the outer side or surface of the cushioning component at the
region that is adapted to contact the bottom lip region of the patient. The outer side has been
divided into an upper and a lower portion, wherein the upper portion is at a reduced angle in
respect to the lower portion. The apex 950 is adapted to rest or engage the cleft formed
between the bottom lip of the patient and lower extremity of the chin. The upper portion is
adapted to engage the patient’s face at a position lower and extending away from the cleft.
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Thereby providing an increased sealing surface between: the patient’s face at the location
between the bottom lip and the lower extremity of the chin; and the outer side of the
cushioning component.
As best shown in Fig. 16g and 25, the patient contacting surface 940 is
generally flat or has a larger radius r2 when compared to the nasal bridge region radius r1.
This arrangement aids in comfort and increases the length of the sealing surface such that a
better seal may be maintained.
In Fig. 25, the radius r2 at the apex of the cushion is preferably about 5mm.
Alternatively, patient contacting surface 940 may have apex 950 that may first
contacts the patients face and anchors the cushion in the dimple of the chin or curvature
between the lower lip and chin region. Apex 950 may have a relatively small radius r2 when
compared to that radius r2 shown in Fig. 16g. Radius r2 may be about 5mm. Patient
contacting surface 940 may also have a kink or inflexion 960 that may generally match the
approximate curvature of the chin so as to rest the cushion on the chin to sealingly engage the
cushion with the patient. This kink 960 also allows apex 950 to flex inwards towards the
centre of the cushion, and outwards away from the centre of the cushion, so as to
accommodate movement of the patient’s chin or jaw. For example, it is possible for patients
to drop their jaw during sleep, so in order to maintain a seal with the patient, the mask must
be able to move with the patient’s jaw. This arrangement further enables a greater fit range of
patients, i.e. kink 960 may flex either inwards or outwards on a patient’s jaw depending on
the length and depth of their chin, other facial features etc.
Additionally, as shown in Figs. 16g and 25, the internal wall 942 of the
cushioning component is arranged substantially vertical or normal to the face of the patient in
use as demonstrated by angle 2150. This arrangement reduces the likelihood of the foam
cushioning component touching the patient's bottom lip when compressed in use, a problem
that may occur for larger faces within each size range.
The preferred maximum width of the cushioning component as measured in
respect of the base surface is generally about 35mm in relation to the bottom lip region. The
preferred maximum height of the cushioning component is generally about 26mm in relation
to the bottom lip region.
In Fig. 25, the angle formed between the outer side and base surface is
approximately between 80-90 degrees; and the angle formed between the inner side and the
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base surface is approximately between 90 to 100 degrees. Preferably, the angle by which the
outer side meets with the base surface is generally less than the angle formed between the
inner side and the base surface.
Side of Nose Region
As shown in Fig. 16h, the cross section at the side nose SN is generally
triangular. The cross section at the side nose region SN may also be another other reasonable
shape, such as generally rectangular, oval, octagonal etc. In addition, it is possible for the
cross section at the side nose region to include a shape with generally rounded or curved
corners. The cross section at the side nose region may also be an irregular shape. Figs. 21
and 22 show an alternative cross section for the side of nose region.
Fig. 16h shows a cross-section of the cushioning component in a side of nose
region SN. Similar to the nasal bridge region NB as shown in Fig. 16g, the cross section is
generally triangular. However the triangular cross section is skewed or biased towards the
inner edge of the cushioning component. This arrangement aids with sealing because inner
wall 944 abuts the side of the patient’s nose in use, thereby increasing the sealing surface.
This is similarly demonstrated in Figs. 21 and 22.
Preferably, the outer side is longer than the inner side. Also preferably, the
angle formed between the outer side and the base surface is generally less than the angle
formed between the inner side and the base surface.
The most preferred maximum width of the side of nose region (as measured
along the base surface) is 22mm and most preferred maximum height of the cushioning
component at the side of nose position is approximately 24mm.
Cheek Region
As shown in Fig. 16i, the cross section at the cheeks C is generally trapezoidal
or triangular. The cross section at the cheeks region C may also be another other reasonable
shape, such as generally rectangular, oval, octagonal etc. In addition, it is possible for the
cross section at the cheeks region to include a shape with generally rounded or curved
corners. The cross section at the cheeks region may also be an irregular shape. Figs. 23 and
24 show an alternative cross section for the cheek region.
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Fig. 16i shows a cross-section of the cushioning component in a cheek region
C. As illustrated, the contacting surface or apex 946 where the cushioning component
contacts the patient's cheek is similar to that at the bottom lip region BL as shown in Fig. 16g.
The cross section is generally triangular, and may have a smaller top surface 946 when
compared to the top surface 940 of the bottom lip region BL. This arrangement aids sealing
around the patient's cheeks in use and increases the comfort of the interfacing portion, while
reducing the bulk of the interfacing portion at the cheek region C.
A similar arrangement is shown in Figs. 23 and 24. However, as shown in Fig.
24, inflexion 950 changes the curvature of the side wall of the cushion so that it may hinge or
bend inwards. This may increase the ability for the cushion to seal on the patient’s face when
in use.
Preferably, the outer side of cushioning component is longer than the inner
side. Also preferably, the angle formed between the outer side and the base surface is
generally less than the angle formed between the inner side and the base surface.
The most preferred maximum width of the cheek region (as measured along
the base surface) is 23mm and most preferred maximum height of the cushioning component
at the cheek region is approximately 24mm.
Additionally, when the clip portion is joined or mounted to the cushioning
component, the apex of the cushion is additionally offset towards the centre or middle of the
mask. In the described embodiments, the apex may be offset to the extent that it overhangs
the point formed between the inner side and the base surface.
2.2.2 Nasal Mask
Figs. 39 to 47 show an alternative embodiment of the present invention.
Cushion component 4000 may be used as a nasal mask that only covers the nose of the
patient in use, and is positioned on the nose bridge, side of nose, cheeks and or upper lip
region and may not cover the patient’s mouth.
Preferably, the cushioning component of the nasal mask shown in respect of
these embodiments is preferably: 70-75mm in length (when measured from the outer most
edges of the base surface of the cushioning component); and the width of the cushioning
component is approximately 75-80mm.
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Nasal Bridge Region, Side of Nose Region and Cheek Region
The nasal bridge region 4200, side of nose region 4300 and cheek region 4400
may be generally similar to that described above for a full face cushion.
The preferred height of the cushioning component at the region designated to
correspond to the nasal bridge of the patient is approximately 22mm. The height of the
cushioning component at the position designated to meet the side of the nose is
approximately 25-27mm. The height of the cushioning component at the position designated
to meet the patient’s cheek regions is approximately 27mm.
The preferred width of the cushioning component in the side of nose regions is
typically about 20mm. Whereas the preferred width of the cushioning component in the
cheek regions is typically about 18mm.
Upper Lip Region
As shown in Figs. 39 and 41, cushion component 4000 may have an upper lip
region 4100 that has a dip or region of reduced height (when viewed from a side view as
shown in Fig. 41) relative to the height of other regions 4200. This feature may accommodate
various upper lip regions of patients whilst avoiding accidental occlusion of the nares. The
overall reduction in the amount of foam material may reduce the risks for patients.
The preferred width of the cushioning component in the upper lip region is
typically about 16mm. The width of the cushioning component in the upper lip region may be
-20mm. The width of the cushioning component in the upper lip region may be 15-20mm.
The width of the cushioning component in the upper lip region may be 12-20mm. The width
of the cushioning component in the upper lip region may be 10-15mm. The width of the
cushioning component in the upper lip region may be 10-18mm. The width of the cushioning
component in the upper lip region may be 10-14mm.
The preferred height of the cushioning component at the region designated to
correspond to the upper lip of the patient is approximately 18mm. The height of the
cushioning component in the upper lip region may be 10-20mm. The height of the cushioning
component in the upper lip region may be 10-25mm. The height of the cushioning component
in the upper lip region may be 15-20mm. The height of the cushioning component in the
upper lip region may be 16-23mm.
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Fit Range
Because of the wide range of sizes and shapes of different people's faces, it is
a continual challenge for mask designers to determine the least number of mask shapes
required to fit the broadest range of patients. In one ideal form, a single mask shape would fit
all patients.
A mask assembly in accordance with the invention provides an improved fit
range. This maybe preferably achieved by combining a more comfortable and compliant
material with a more anatomically neutral geometry that seals against a wider range of facial
anatomy for a given shape.
The versatility of a chosen cushion shape, and hence its fit range performance,
is also enhanced by the ‘hovercraft’ behavior exhibited by the cushion. In this context the
“hovercraft’ behavior is generally defined by the air pressure in the cavity of the mask when
the air pressure in cavity of the mask is greater than the outside environmental air pressure
and thereby allows the mask to float on the face of the wearer. The pressure seal is preferably
formed by the cushioning component. This feature may enhance the ease and speed of fitting
the mask.
When pressurized with air the cushion material has extra extensibility
compared to other known cushion materials. The soft flexible cells in the foam material
effectively stretch when inflated allowing the material the freedom to enlarge. This allows the
cushion material to have an extra dimension of conformability over other cushion materials
known in the art e.g. silicone, by being able to expand and morph to facial anatomy when
inflated with air pressure. This is, in part, also achieved by combining an expandable open-
cellular structure in direct communication with the air that is providing the positive airway
pressurization. It is the flow of air through the sealing material that forms a fine layer of
pressurized air between the facial skin, and the flexible nature of the cushion material that
enables this hovercraft effect, hence making it easier to fit to the face. The foam being less
sticky than silicone also has a significant advantage in achieving an easy, fast and
comfortable fit.
2.3 Method of Manufacturing
The following manufacturing techniques may be used to create a range of
shapes and cross-sections as may be required for different facial shapes. Since the cushioning
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component is preferably made from unskinned foam, one or more cutting processes may be
used to create the part, such cutting processes including die cutting, and/or machining, etc.
Alternatively the cushioning component may be molded with measures taken in the process
to minimize the skin on the foam component, or the skin being subsequently removed from
the molded component in a post process e.g. machined. Preferably, the foam material used in
the herein described embodiments may be an open and closed cell foam. The foam material
used may be an open cell foam. The foam material used may be a closed cell foam.
2.3.1 Die Cutting
In the illustrated embodiment shown in Figs. 4a-4g, both an inside surface and
an outside surface of the foam cushion component 232 are die cut. This typically results in
generally straight cut edges. The cushion in these embodiments may have a generally
rectangular cross section, where the top surface is generally substantially parallel to the
patient’s face in use, and the inner and outer side surfaces are generally perpendicular to the
patient’s face in use. It may be possible to die cut the foam using additional processing steps
to create a non-rectangular cross section, e.g. the use of shims. The die cutting of a cushion
component then from a flat sheet of foam results in a flat backed cushion component which
may subsequently take the shape of a clip that it is assembled to e.g. glued. The foam cushion
is therefore deformed into its final intended shape.
To create a curved backed cushion, that for example matches the shape of a
curved clip without stretching or deformation, the cushion component may be die cut from a
foam sheet that is cut into a curved shape rather than a flat sheet. The curved sheets may be
formed from a known process referred to as contour cutting, where a foam block is cut into
curved sheets by being fed into an oscillating blade that changes position and orientation
during the cutting process.
In addition to die cutting or in the alternative, the cushioning component, e.g.,
as shown in Figs. 9a to 12f, may be cut into a three-dimensional shape or geometry using the
techniques described in AU 2008904769 and AU 2008904778.
Figs. 9a to 9d illustrate a foam-based interfacing structure 430 including a
foam cushion component 432 and a clip portion 434. Outer wall 400 may include contours
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and curvature incorporated into the design. The inner, patient contacting wall (or orifice) 402
may be die cut as known in the art. Again, this typically results in straight cut edges (e.g., see
Figs. 9b and 9d).
Figs. 10a to 10c illustrate a foam-based interfacing structure 330 including a
foam cushion component 332 and a clip portion 334, wherein the cushion component 332
includes localized regions with curvature or ridges, e.g., ridges 350 along cheek regions of
the cushion component, a curvature 352 along the nasal bridge region of the cushion
component, etc. In addition, the cushion component 332 is contoured along the chin region
of the cushion component. The straight die cut inner and outer edges remain perpendicular to
the patient’s face in use similar to the previous embodiment.
Figs. 11a to 11c illustrate a foam-based interfacing structure 530 where a
localized region 552 in the cushion component 532 at the nasal bridge has been raised, e.g.,
formed with a curved surface.
Figs. 12a to 12f illustrate another embodiment in which a foam-based
interfacing structure 630 including a foam cushion component 632 and a clip portion 634,
wherein the foam cushion component 632 includes a slab of foam that is cut using methods
known in the art. This process may be repeated in order to cut the outer wall 600 of the
cushion component and then the inner, patient contacting wall (or orifice) 602 of the cushion
component.
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3. CLIP COMPONENT
3.1 Material
The cushion-to-frame component may be made from a material that has
greater structural integrity than the cushioning component. In a preferred embodiment the
clip is made from polyurethane foam that has higher hardness, higher density, and lower
permeability than the foam used for the cushioning component. The clip/cushion-to-frame
component may be formed in a mould giving rise to a harder, denser, lower permeability
foam having a skin. In an alternatively preferred embodiment, the clip may be constructed of
a non-foamed polymer, for example (but not limited to), nylon, polycarbonate,
polypropylene.
Preferably, the clip portion or clip component may be of reduced hardness or
increased flexibility in comparison to the frame portion of the mask to which it is to
connected or secured with.
3.2 Shape
The clip 934 is shown generally in Fig. 13, and in more detail in Figs. 15a-
15e. The clip 934 is generally shaped in order to align with the frame. However, the general
curvature of the clip 934 can be altered to suit the frame to which it is to be fitted. The
general curvature of the clip may also be used to shape the cushion component. Since the
cushion component is made from compliant foam, it will readily adapt to the shape of the clip
when joined together. An example of where this may be an advantage is when the cushion
component is made to have a flat back (from a flat foam sheet as described previously) and is
given its final shape by assembly (e.g. glued) to a clip that gives the cushion its intended
shape (e.g. curved).
The clip may also be made flat. The cushion can therefore also be made with a
flat back to match the clip. The overall intended shape of the interfacing structure
(combination of clip and cushion) can therefore be alternatively achieved by the flat clip and
cushion being deformed and retained into a curved frame. This embodiment allows clip to be
manufactured flat which can have several advantages including ease of handling and
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alignment during manufacture, packaging and transportation. The clip can therefore be
formed by alternative methods e.g. die cutting from flat sheet material.
The clip may also be made curved. This may be achieved by several means
including molding directly into a curved shape, die cutting from curved (contour cut) sheet,
or heat forming a flat clip die cut from a thermoformable material. Having the clip curved
allows ease of alignment and assembly to a curved frame, as well as giving the cushion a
curved shape if the cushion is made from a process that results in it having a flat back.
In a preferred embodiment the clip is made from molded polyurethane. The
cushion contacting surface 935 is generally smooth so that it can continuously join and seal to
the underside of the cushion. Cushion contacting surface 935 has a lip 935a to enable
alignment of the clip to the frame.
Frame contacting surface 937 has three alignment tabs 938 protruding from its
surface that engage with the frame. There may be any number of alignment tabs 938 to aid
the patient in aligning the interface structure with the anchoring structure. It should also be
appreciated that the clip need not have alignment tabs 938 to engage the clip with the frame.
The clip may also be made to incorporate features that engage the frame to aid
retention of the interfacing structure to the frame. Examples include, but are not limited to,
surface roughening, ribs, notches, snaps etc.
3.3 Method of Manufacturing
The clip component may be separately formed as will be now described, or
insert molded as will be described later in this specification.
By way of example, Figs. 18a to 18c illustrate a tool to mold a clip portion by
itself, where the clip portion may subsequently be attached to the cushion component, e.g., by
an adhesive or simply adhesion between the clip and cushion component. As illustrated, the
tool includes a top half 1560 and a bottom half 1565 which are adapted to be joined together
to form the clip portion. As shown in Fig. 18b, the tool provides a curved parting line PL
between the top and bottom halves 1560, 1565.
The bottom half 1565 includes a cavity 1567 adapted to receive the material
(e.g., foaming mixture) that will form the clip portion. Also, the center section 1568 of the
bottom half 1565 accommodates a separate insert that acts as a manual ejection feature after
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molding. The top half 1560 provides a surface 1562 that will form the side of the clip portion
for interfacing or joining with the cushion component.
The top and bottom halves 1560, 1565 of the tool are constructed and/or
arranged to facilitate demolding of the clip portion from the tool so that the clip portion will
not adhere to the tool. For example, the top and bottom halves 1560, 1565 may be
constructed of a material from which the mold material (e.g., foaming mixture) may be
removed (e.g., high density polypropylene, silicone). Alternatively, a demolding agent (e.g.,
wax) may be provided to the top and bottom halves to facilitate demolding.
An alternative demolding aid may be a release film that lines the tool and
releases from the clip material easily after molding. In a preferred embodiment the release
film may double, in whole or in part, as the packaging for the interfacing structure such that
the product leaves the molding process already packaged. In another embodiment the clip
includes a tab at one or a number of locations that facilitates gripping of the part for
demolding during the manufacturing process. This tab feature may also double as an
alignment feature for assembly and a gripping feature for disassembly for the user of the
mask assembly.
In another embodiment the clip may include a tab feature that includes an end
of life indicator for the interfacing structure.
4. SUB-ASSEMBLY
4.1 Relative position
In accordance with an embodiment of the invention, a range of different
arrangements of clip portions and cushion components may be provided. For example, the
width of the clip portion may preferably match or be less than the maximum width of the
cushion component, the width of the cross section of clip portion may be less than the width
of the cross section of the cushion component. In these different configurations with different
relative widths, the clip portion provides different forms of support to the cushion
component.
Wherein the width of the cross section of the clip portion is less than the width
of the cross section of cushion component, the clip portion and cushion component may be
arranged such that (i) the outer perimeter of the clip portion and cushion component align
(hides hardness of clip portion and provides desired freedom of movement in the cushion
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component), (ii) the inner perimeter of the clip portion and the cushion component align, or
(iii) neither the inner or outer perimeter of the clip portion and the cushion component align.
Similarly, wherein the width of the clip portion is greater than the width of the
cushion component, the clip portion and cushion component may be arranged such that (i) the
outer perimeter of the clip portion and cushion component align, (ii) the inner perimeter of
the clip portion and cushion component align, or (iii) neither the inner or outer perimeter of
the clip portion and the cushion component align.
When the width of the clip portion is less than the width of the cushion
component and the outer perimeter of the clip portion aligns with the cushion component, the
cushion component may preferably be more able to flex in regions or directions not having a
clip portion next to it than in regions having a clip portion adjacent to it or supporting it. For
example, where the cushion component overhangs the clip portion, that overhanging region
of the cushion component has more freedom to move. This arrangement can be more
comfortable and more able to adapt to different geometries of a person, and provide the
correct vectors to seal the cushion component against the face.
Preferably, the clip portion is to be joined to a cushioning component by a
base surface of the cushioning component. It may also be preferably to arrange the clip
portion to support the external extremity (relative to the circumference of the mask) of the
base surface and to have no or little support inner extremity of the base surface.
When used as part of a respiratory mask, it may be preferable that the inner
portion of the cushion component overhang the clip portion. In this arrangement in use, the
face of the patient may engage with an unsupported inner edge of the softer cushion
component causing it to bend and conform to the individual patient's shape. When the mask
engages a patient’s face, the cushioning component may roll inwards towards the centre of
the mask when pressure is applied on the mask towards the patient’s face.
Fig. 7a shows an elevation view detail from the frame side of the interfacing
structure 230 shown in Fig. 4e in a nasal bridge region. As shown in cross-section in Fig. 7b,
it is apparent that the width w2 of the clip portion 234 is less than the width w1 of the cushion
component 232 and that the outer perimeter of the clip portion 234 and the cushion
component 232 are aligned. An advantage of this arrangement is illustrated in Fig. 7c where
in use the nose is able to push the inner perimeter of the cushion component 232 in the
direction shown by the arrow, in a cantilever manner as well as compressing. Fig. 8 is a
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cross-section showing the clip portion 234 of the interfacing structure 230 received within the
channel 22 of a mask frame 20.
This arrangement is in contrast to prior art cushions (such as the Lifecare™
mask shown in Figs. 6a and 6b) where the inner perimeter of the cushion C abuts the frame F,
and hence it is not free to move inwardly and can only compress.
Figs. 26-32 show an alternative embodiment of the present invention. Fig. 26
shows the cross sections later shown in Figs. 27-32. Cushion component 3232 may be
attached to clip component 3234. Cushion component 3232 may be similar to that shown in
Figs. 19-25. Clip component 3234 may have upper surface 3500 that attaches to cushion
component 3232. Upper surface 3500 may be generally horizontal when in use or assembled,
as shown in Fig. 27, 28, and 29. In addition, this may position the tangent to apex 3600 of the
cushion component 3232 generally parallel to upper surface 3500. Alternatively, upper
surface 3500 may be generally curved or angled inwards towards the inner portion of the
cushion so as to angle the cushion more towards the centre of the patient’s face, as shown in
Figs. 30, 31, and 32. Therefore, tangent to apex 3600 may not be parallel to upper surface
3500. In an embodiment, the upper surface 3500 may be angled in one or more selected
regions, e.g., lower cheek or chin regions to fit patients with more narrow, shallow faces (see
Figs. 30-32).
In an embodiment, as shown in Figs. 27-32, the outer edge of the cushion
component may slightly overhang (e.g., 1 mm overhang) the clip component, e.g., for
manufacturability.
4.2 Glue
The two layers (i.e., the cushion component and the clip portion) may be
adhered to one another using polyurethane hot melt glue or cyanoacrylate.
In alternate embodiments (not shown in Figures) the cushioning portion may
be directly glued onto the frame.
4.3 Insert Molding
In a manufacturing process according to an embodiment of the present
invention, insert molding may be used to assemble the cushioning component to the cushion-
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to-frame component. An advantage of this approach include lower cost when compared to
other processes such as gluing.
Figs. 17a to 17h illustrate a tool and manufacturing process for manufacturing
an interfacing structure according to an embodiment of the present invention.
As best shown in Fig. 17a, the tool includes a first portion 1060 adapted to
receive the cushioning component that may be cut from foam slabstock and a second portion
1065 adapted to receive the foaming mixture that will form the cushion-to-frame component.
The first portion 1060 of the tool may allow a vacuum to be applied to the
cushioning component to retain it in position. For example, as shown in Fig. 17a, the walls
of the cavity that receive the cushioning component include a plurality of orifices 1062, and a
vacuum is applied to an opening 1063 in the side wall of the first portion 1060 so that the
cushioning component may be drawn into the cavity. The first portion 1060 may be sized to
provide an interference fit with the cushioning component.
The first and second portions 1060, 1065 of the tool are arranged so that there
will be a region of contact between the cushioning component and the cushion-to-frame
component such that they will adhere to one another.
At least a second portion of the tool is constructed and/or arranged to facilitate
demolding of the cushion-to-frame component that would otherwise adhere to the tool.
Preferably, this is achieved by using a tool constructed of a material from which the foam
may be removed (e.g., high density polypropylene, silicone). Alternatively, steel or
aluminum tools may be used, provided an appropriate de-molding agent can be used, such as
wax (e.g., agent that does not present biocompatibility issues).
In the illustrated embodiment as best shown in Fig. 17a, the second portion
1065 includes three parts that are removably attached to one another, i.e., an inner portion
1066(1), and outer portion 1066(2), and a ring portion 1066(3).
An insert molding manufacturing process according to an embodiment of the
invention will now be described in greater detail.
Fig. 17a illustrates the first and second portions 1060, 1065 of the tool
separated from one another. In Figs. 17b and 17c, the cushioning component 1032 is placed
in the first portion 1060 of the tool. The cushioning component 1032 may be held in place in
the first portion 1060 by a vacuum and may impart curvature on the cushioning component
via the vacuum. This may be necessary if the cushion is made from a process that gives is a
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flat backed geometry. Placement of the cushioning component 1032 may be manual or
automated. For example, the cushioning component 1032 may be sucked into the first
portion 1060 using the vacuum.
In Fig. 17d, a mixture of polyurethane (e.g. foam or elastomer) is prepared to
form the cushion-to-frame component 1034 and the high-intensity mix is poured into the
second portion 1065 of the tool. Pouring of the mix for the cushion-to-frame component
1034 may be manual or automated. If the cushion-to-frame component 1034 is made from a
foam the cavity of the second portion 1065 will only be partly filled (e.g., 25%) and during
the foaming process it will expand to fill the space and come into contact with the cushioning
component where it will adhere.
In Fig. 17e, the first and second portions 1060, 1065 of the tool are clamped
together or closed to allow the cushion-to-frame component foaming reaction to proceed in
the tool. That is, the foam for the cushion-to-frame component 1034 can rise up and
chemically bond or adhere to the foam cushioning component 1032. The choice of clip
material may enhance the bonding or adhesion process. In a preferred embodiment both the
clip and the cushion are made from polyurethane material for ideal bond integrity between
the two components. Additionally, should the cushion component have a regular, uniform,
rough, irregular or non-uniform cell structure, the clip component may infuse into gaps in the
cell structure of the cushion component, forming small mechanical bonds between the
components.
When the cushion-to-frame component 1034 has cured, the vacuum first
portion and second portion are separated as shown in Fig. 17f. In Fig. 17g, the ring portion
1066(3) at the bottom of the second portion 1065 is removed and the inner portion 1066(1) is
ejected to demold the cushion-to-frame component 1034. Fig. 17h shows the resulting
interfacing structure 1030 removed from the tool with the cushioning component 1032
adhered to the cushion-to-frame component 1034. In a preferred embodiment the cushion
component is originally flat when vacuum inserted into the top half of the tool and is bonded
to a curved clip during the insert molding process. The resultant interfacing structure then
assumes an intended curved shape.
In an alternative embodiment the cushion and clip are made flat but the
cushion is made with sufficient depth to not require curvature to suitably adapt to the face
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when worn; but rather suitably deforms to the shape of the face due to the softness and depth
of the cushion foam.
In another alternative arrangement, a film may be added to the second portion
of the tool prior to the addition of the foaming mixture. This film may be structured to
facilitate removal of the otherwise adhering cushion-to-frame component. The film may be
used to form packaging for the interfacing structure.
In an embodiment, the clip portion of the interfacing structure may be
constructed from more rigid and denser foam than the cushion component. For example, the
clip portion may be formed from nitrogen blown polyethylene, or some other biocompatible
foam having a fine cell-structure. Alternatively, the clip portion could be made from some
other polymer or rubber. In an embodiment, the clip portion is adapted to form a cushion-to-
frame engagement mechanism and to form a structural support for the cushion component.
Preferably, the cushioning component is less rigid, less stiff or more flexible
than the clip portion, which is in turn less rigid, less stiff or more flexible than the frame of
the mask. Preferably, the frame gives shape to the mask interfacing structure, wherein the
interfacing structure is relatively flexible and less rigid, overall than the frame. This feature
adds comfort and also allows the interfacing structure to be easily replaced by the patient or
user. Further improvements to the interfacing structure may be made to adapt the shape and
configuration to be disposable.
For example, Fig. 13 shows a clip portion 734 including a side 735 for
interfacing with a foam-based cushion component and a side 737 for interfacing with a mask
frame. In this embodiment, the clip portion 734 is constructed of a skinned foam and may be
formed by molding. The foam of the clip portion 734 may be harder or more dense than the
foam of the cushion component. Alternatively, the more dense or harder foam may be formed
by cutting, e.g., die cutting, machining, and/or the methods set forth in AU 2008904769 and
AU 2008904778.
This arrangement provides a one piece interfacing structure with a cushion
component adapted to engage the patient's face and a clip portion adapted to interface with
the mask frame.
In one form, a mask system may be provided that includes at least two
different forms of interfacing structure chosen from the set of foam-based cushion, silicone-
based cushion, and gel-based cushion.
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Figs. 14a to 16i illustrate an interfacing structure 930 including a cushion
component 932 and a cushion-to-frame component or clip portion 934 provided to the
cushioning component 932. Figs. 14a to 14f show the cushioning component 932 attached to
the cushion-to-frame component 934, Figs. 15a to 15e are isolated views of the cushion-to-
frame component 934, and Figs. 16a to 16i are isolated views of the cushioning component
932.
As shown in Figs. 14a to 15e, the cushion-to-frame component 934 includes a
side 935 for interfacing with the cushioning component 932 and a side 937 for interfacing
with a mask frame. The side 937 includes protrusions 938 to facilitate and/or enhance
attachment to the mask frame.
. ASSEMBLING THE FRAME AND INTERFACING STRUCTURE
The interfacing structure is constructed as described above and arranged for
removable interconnection with the rest of the apparatus, for example a respiratory mask.
The ability to removably connect the interfacing structure enables one to
replace the interfacing structure should it become soiled, damaged, uncomfortable or
otherwise aged as a result of usage. It also facilitates trial or testing of different arrays of
interfacing structures which are selected on different patients facial types or features (e.g.,
narrower face, longer nose, or longer chin, etc.) . One form of interfacing structure, for
example a foam-based interfacing structure, may be used as a form of “training” system to
allow a person to become accustomed to the sensation of wearing and using a mask. A foam-
cushion based mask may provide an initially more appealing and comfortable surface for a
new patient than a gel or silicone-based cushion. The patient may subsequently switch from
the foam-based cushion to a silicone or gel based cushion. In this way, the patient may be
more likely to adhere to therapy because they are used to the very soft comfortable feeling of
foam.
When applied to respiratory equipment, the interfacing structure is adapted for
connection with a mask frame. In use, a seal is formed between the interfacing structure and
the frame. This arrangement could be used for both nasal and full-face masks. The seal
between the frame and interfacing structure may seal better wherein the clip portion is less
rigid or more flexible than the frame.
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For example, Fig. 1 illustrates a mask 10 including a mask frame 20 a foam-
based interfacing structure 30 provided to the mask frame 20. As illustrated, the foam-based
interfacing structure 30 provides a foam cushion component 32 adapted to contact the
patient's face in use. In this embodiment, the foam-based interfacing structure 30 is adapted
for use with an existing mask (e.g., ResMed's Mirage Quattro mask), which allows the patient
to switch from the foam-based interfacing structure 30 to the mask's existing silicone-based
cushion if desired.
Figs. 4a to 4g show a foam-based interfacing structure 230 according to an
embodiment of the invention. As illustrated, the interfacing structure 230 includes a cushion
component or face-contacting portion 232 and a clip portion 234 provided to the cushion
component 232. In this embodiment, the clip portion 234 is adapted for an interference fit
with a mask frame, and the width of the clip portion 234 is narrower than the width of the
cushion component 232 (e.g., see Figs. 4e and 4g).
.1 Cushion-to-Frame Engagement Mechanisms
According to an aspect of the invention, the cushion-to-frame engagement and
connection mechanism provided by the clip portion may include a channel-type engagement
or rib-type engagement.
As shown in Fig. 2, the channel-type engagement includes a foam clip portion
34 that is adapted to be received within the channel 22 of a mask frame 20 with an
interference fit. The foam clip portion 34 extends around the entire perimeter of the
interfacing structure so as to form a seal and retention with the mask frame.
As shown in Figs. 3a to 3c, the rib-type engagement includes a foam clip
portion 34 with one or more slots 38 to receive inner and/or outer ribs 23, 24 of the mask
frame 20. For example, the slot to rib engagement may provide an inner frame rib
engagement (see Fig. 3a), an outer frame rib engagement (see Fig. 3b), or an inner and outer
frame rib engagement (see Fig. 3c). This arrangement provides a broader base of support for
the sealing foam.
Figs. 5a and 5b illustrate a foam-based interfacing structure 830 including a
foam cushion component 832 and a clip portion 834, and Fig. 5c illustrates the interfacing
structure 830 provided to a mask frame 20. As shown in Figs. 5a and 5b, the clip portion 834
includes a slot 838 adapted to receive a rib of the mask frame 20. Also, providing a wider
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clip portion 834 allows more stiffness and structural integrity to be provided to the clip
portion, making the clip portion easier to assemble to the mask frame.
When structured to form an interference fit with the mask frame, the clip
portion may have the following properties: appropriate rigidity (e.g., less than that of the
frame and in one form more rigid than the foam cushion component); non-porous; and/or low
compression set (the amount of deformation expressed as a percentage of original
dimensions) which a material retains after compressive stress is released (in this way, the clip
portion maintains its retention force during its usage life).
Additionally, the clip portion may include an additional extension (not shown)
that extends beyond the outer extremity of the frame which is adapted to be gripped by the
patient for easier removal of the interfacing structure. Preferably, this extension would be
positioned in a region that is easy for the patient to grip such as the nasal bridge of the mask.
Preferably, the extension will be small enough not to impede vision of the user or to affect the
overall efficiency or seal of the mask. Preferable, the extension may function as a finger grip
for the patient to remove or replace the interfacing structure, when desired.
Figs. 50-1 to 57-2 illustrate alternative mechanisms for attaching the clip
portion to the frame. In Figs. 50-1 and 50-1, the clip portion 5034 is in the form of a
microcellular polyurethane clip adapted to engage within the frame channel 5022 with an
interference fit. In Figs. 51-1 and 51-2, the clip portion 5034 is in the form of a flexible
plastic clip (e.g., Hytrel, TPE) adapted to engage the frame channel 5022 with a snap fit. The
clip portion also includes a lip seal 5035 adapted to engage the channel wall. In Figs. 52-2
and 52-2, the clip portion 5034 is in the form of a flexible plastic clip adapted to engage the
frame channel 5022 with a snap fit. The clip portion also includes a sealing element 5035
(thermoplastic elastomer that may be over molded on to the clip portion) adapted to engage
the channel wall. In Figs. 53-1 and 53-2, the clip portion 5034 is in the form of a
polyurethane clip adapted to engage within the frame channel 5022 with an interference fit.
The clip portion also includes a flexible plastic clip 5036 (assembled to the polyurethane clip)
adapted to engage the frame channel with a snap fit. In Figs. 54-1 and 54-2, the clip portion
5034 is in the form of a polyurethane clip adapted to engage within the frame channel 5022
with an interference fit. The clip portion also includes a flexible plastic clip 5036 (glued to
the polyurethane clip) adapted to engage the frame channel with a snap fit. In Figs. 55-1 and
55-2, the clip portion 5034 includes a flexible plastic clip adapted to engage the frame
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channel 5022 with a snap fit or other fitting means e.g. interference fit. In addition, the clip is
contoured such that the clip also engages the channel wall with an interference fit. In Figs.
56-1 and 56-2, the clip portion 5034 includes a flexible plastic clip adapted to engage the
frame channel with a snap fit. The clip portion also includes a foam element 5037 adapted to
cover the clip. In Figs. 57-1 and 57-2, the clip portion 5034 includes a polyurethane clip
(attached to cushion component by plastic element 5038) adapted to engage the frame
channel 5022 with a snap fit. The frame channel includes a plastic extension 5023 adapted to
engage the clip. This arrangement allows replacement of the cushion component without the
need to change the clip portion.
6. Exemplary Materials and Properties
The following provides exemplary materials and properties of the cushion
component and clip portion.
6.1 Cushion Component
In an embodiment, the cushion component may be made from polyurethane,
be resistance to hydrolysis and/or resistant to microbial attack.
In an embodiment, the cushion component may be air permeable. In an
embodiment, the cushion component may not be air permeable.
In an embodiment, the cushion component may be able to maintain its air
permeability over a period of use.
Preferably, the cushion component may not emit harmful or odorous volatiles
or particulates.
Preferably, the cushion component may be coloured and this colour may not
fade.
Fig. 48 is a chart showing exemplary material properties for the cushion
component.
In one example, properties of the foam cushion component may include:
density (relates to other foam properties and affects cost and weight of the cushion, e.g.,
higher density can reduce air permeability and higher density can increase hardness); air
permeability (flow of air through cushion contributes to total mask flow characteristic of the
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mask which may affect compatibility with PAP devices); hardness (affects comfort and
sealing performance); tear resistance (contributes to durability); tensile strength (contributes
to durability); and/or tensile stiffness (resists the deforming effects of positive air pressure
inside the mask).
6.2 Clip Portion
Fig. 49 is a chart showing exemplary material properties for the clip portion.
In one example, properties of the foam clip portion may include: density
(affects weight); air permeability (permeability of the foam itself may not be critical if it is
molded with a skin that renders it impermeable); hardness (soft and flexible enough to
assemble to the frame with an interference fit and seal against the frame);
elasticity/viscoelasticity (soft and flexible enough to assemble to the frame with an
interference fit and seal against the frame); and/or compression set (should not deform over
time to ensure easy assembly/retention).
6.3 Testing Methods
The following provides exemplary testing methods for determining material
properties.
6.3.1 Air Permeability
Air permeability is defined as “the rate of air flowing through a foam sample
(in L/min)”.
This test measures the flow through a regular shape with a constant cross
section, in a manner analogous to a cushion in real use. In the example of Fig. 60-1, the test
specimen is an annulus of foam, about 30 mm thick. The circular shape ensures that pressure
is evenly distributed and the foam inflates uniformly.
The foam sample is cut normal to cell rise direction as shown in Fig. 60-4.
The wall section of the foam specimen may be rectangular (see Fig. 60-2), but
it is possible for the wall section to have a concave outer surface and a convex inner surface
(see Fig. 60-3).
The annular foam sample is held at a defined height between two plates in a
Universal Test Machine (e.g., Instron). Air at a given pressure is directed into the centre of
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the annulus and flows out through the foam. The air flow rate and reaction force of the foam
against the plates may be measured. Fig. 60-5 is a schematic of the test set up.
As shown in Figs. 60-6, 60-7, and 60-8, the test jig used to hold the foam
consists of: an aluminum base plate that locates the foam and seals against the flat bottom
surface of foam annulus; an air inlet and pressure port in the centre of the base plate; a clear
polycarbonate top plate that seals against the flat bottom surface of foam annulus and allows
observation of the test sample; and a part glued to the top plate to connect with a load cell
attachment on the Universal Testing Machine (UTM).
Once set up, attach the top plate to the crosshead of the UTM, zero the load
cell of the UTM.
Zero the displacement of the UTM at the uncompressed height of the foam
sample, i.e., 30 mm above the base plate sealing surface.
If there is variation of 1 mm or more in the thickness of the samples, then for
each sample: (i) assemble the foam sample into the test jig; (ii) lower the crosshead just until
a positive force is read on the UTM, e.g., 0.2 N; and (iii) zero the displacement.
Lower the crosshead at 50 ± 20 mm/min until 40%compression displacement
is reached.
Immediately record the reaction force, at 0 cmH O.
Wait 60 seconds and again record the force.
Immediately but gradually adjust the flow generator to 4 cmH O (and
immediately record force and flow rate.
Wait 60 seconds and again record the force and flow rate.
Repeat steps 7 and 8 for 12 cmH O and 20 cmH O.
6.3.2 Hardness
Hardness is defines as “force required to indent a test piece of foam to a stated
percentage of its original thickness”.
Hardness may be tested using an IDM Universal Test Machine, or equivalent
(e.g., see circular flat indenter of Fig. 61)
If applicable, precondition the foam as specified in AS 2282.2-1999.
1524123
James & Wells Ref: 505071DIV1/60
Test the foam according to AS 2282.8—1999 Method A – Indentation force
on deflection test.
Report IF , the reaction force at 40 % compression after 60 seconds
indentation, H60s.
Also report the reaction force at 40 % compression after 2 seconds
indentation, H2s.
Report the sag factor or support factor, i.e., the ratio of 65% to 25% IFD value.
6.3.3 Tensile Strength
Tensile strength may be measured using an IDM Universal Test Machine, or
equivalent. See Fig. 62-1.
Test both directions, i.e., parallel to and normal to the direction of cell rise.
Apply the following deviations from AS 2282.6-1999:
Do not reject test pieces that break outside the gauge length.
Record whether the test piece did break, did not break or came out of the jaws
before maximum elongation was reached.
Three test pieces may be acceptable if the results are consistent (no individual
value deviates more than 20% from the mean of the three values).
Select a typical or representative results curve by inspecting the graphs. Select
a suitably linear region near the start of the curve. (The start of the curve is more
representative of real use than an extremely stretched region and also ensures the result is not
affected by the test sample sliding out of the gripping jaws.)
Calculate the change in force over a distance of at least 25 mm and divide by
the distance to obtain the stiffness value in N/mm.
For example, the curve in Fig. 62-2 is most linear near the start of the curve,
between 25 mm and 50 mm. Stiffness was calculated as follows.
k = ΔF /Δx = (F – F ) / (50 – 25)
tensile 50mm 25mm
6.3.4 Tear Resistance
Tear resistance is defined as the force required to propagate a tear in a pre-cut
sample. See Fig. 63-1.
1524123
James & Wells Ref: 505071DIV1/60
Test according to AS 2282.7-1999 with the following parameters:
The speed of separation of the jaws holding the test piece shall be 200
mm/min.
Test all three directions defined in Figs. 63-2, 63-3, and 63-4. Test and report
the tear resistance results (σ ) for each direction separately.
Apply the following deviations from AS 2282.7-1999:
Do not use a knife or blade to assist the direction of tear. Allow the foam to
tear naturally.
It may not be possible to tear a 50 mm length of foam. Tear as far as possible
up to 50 mm.
Total Mask Flow
This test measures the flow through only the foam cushion, by blocking the
mask vent all other leak paths. See Fig. 64.
The cushion is compressed by 40% of its 30 mm thickness, i.e., 12 mm.
1524123
James & Wells Ref: 505071DIV1/60
7. OTHER FEATURES
In an embodiment, a mask frame may be integrally molded or formed with the
cushion-to-frame component 1034. For example, the second portion 1065 of the tool may be
structured to mold the cushion-to-frame component together with the mask frame.
In the illustrated embodiment, a polyurethane foam cushioning component is
provided to a polyurethane foam or polyurethane elastomer cushion-to-frame component. In
an alternative embodiment, one or both of the components may be constructed of a gel
material. For example, both components may be constructed of gel, the cushioning
component may be constructed of gel and the cushion-to-frame component may be
constructed of foam, or the cushioning component may be constructed of foam and the
cushion-to-frame component may be constructed of gel.
While the invention has been described in connection with what are presently
considered to be the most practical and preferred embodiments, it is to be understood that the
invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to
cover various modifications and equivalent arrangements included within the spirit and scope
of the invention. For example the cutting techniques used for the cushioning component may
also be used for the clip component, or the interfacing structure. Also, the various
embodiments described above may be implemented in conjunction with other embodiments,
e.g., aspects of one embodiment may be combined with aspects of another embodiment to
realize yet other embodiments. Further, each independent feature or component of any given
assembly may constitute an additional embodiment. In addition, while the invention has
particular application to patients who suffer from OSA, it is to be appreciated that patients
who suffer from other illnesses (e.g., congestive heart failure, diabetes, morbid obesity,
stroke, bariatric surgery, etc.) can derive benefit from the above teachings. Moreover, the
above teachings have applicability with patients and non-patients alike in non-medical
applications.
1524123
James & Wells Ref: 505071DIV5
Claims (24)
1. A respiratory mask to provide a supply of pressurized air to the entrance of the airways of a patient for treatment of sleep disordered breathing, comprising: a frame, and an interfacing structure comprising a connection portion and a cushioning component joined to the connection portion; the connection portion being configured to attach to the frame to connect the cushioning component to the frame and being of reduced hardness or increased flexibility as compared to the frame, the cushioning component being at least partially constructed from a foam material and being configured to directly engage and form a seal with a region of the patient’s face in the vicinity of an entrance to the patient’s airways, wherein an interior of the interfacing structure at least partially forms a cavity to receive at least a portion of the patient’s nose in use, wherein a connection portion attachment surface of the connection portion is joined to a cushioning component attachment surface of the cushioning component, wherein at least one of the following parameters of the interfacing structure varies around a perimeter of the interfacing structure and at least contributes to a roll- in effect of the cushioning component: 1) an amount of offset between an inner edge of the connection portion attachment surface and an inner edge of the cushioning component attachment surface; 2) a cross-sectional profile of the connection portion; 3) an offset of an apex of a cross-sectional profile of the cushioning component; and 4) an angle of the connection portion attachment surface in a radial direction of the interfacing structure.
2. The respiratory mask of claim 1, wherein the cross-sectional profile of the connection portion in a cheek region of the interfacing structure is different than the cross-sectional profile of the connection portion in a nasal bridge region of the James & Wells Ref: 505071DIV5 interfacing structure.
3. The respiratory mask of any one of claims 1 and 2, wherein the offset of the apex of the cross-sectional profile of the cushioning component in a / the cheek region of the interfacing structure is different than the offset in a lip region of the interfacing structure.
4. The respiratory mask of any one of claims 1 to 3, wherein the connection portion attachment surface is angled inwardly towards an inner portion of the mask in at least one region of the cushioning component to assist in the rolling-in effect of the cushioning component when the mask is worn.
5. The respiratory mask of any one of claims 1 to 4, wherein the foam of the cushioning component has a density in the range of 40-70 kg/m , and an IFD hardness measured in the range of 70 to 160N at 40% compression using the AS 2282.8 testing standard.
6. The respiratory mask of any one of claims 1 to 5, wherein the foam of the cushioning component has a tear resistance in the range of 100-500 N/m, and an air permeability in the range of 1 to 16 L/min at 40% compression 20 cmH 0.
7. The respiratory mask of any one of claims 1 to 6, wherein the connection portion is configured to directly connect to the frame, the connection portion being arranged to support the foam of the cushioning component and connect the cushioning component to the frame.
8. The respiratory mask of any one of claims 1 to 6, wherein the connection portion is integrally formed with the frame.
9. The respiratory mask of any one of claims 1 to 8, wherein, in at least one region of the cushioning component, the inner edge of the connection portion attachment surface is offset outwardly from the inner edge of the cushioning component attachment surface, leaving an inner portion of the cushioning component James & Wells Ref: 505071DIV5 unsupported, to facilitate the rolling-in effect.
10. The respiratory mask of claim 9, wherein, in the at least one region of the cushioning component having the offset, a width of the connection portion is less than a width of the cushioning component such that the cushioning component overhangs the connection portion.
11. The respiratory mask of any one of claims 1 to 10, wherein an outer perimeter of the connection portion is aligned with an outer perimeter of the cushioning component.
12. The respiratory mask of any one of claims 1 to 11, wherein the connection portion comprises a material that has different material properties than the foam of the cushioning component.
13. The respiratory mask of any one of claims 1 to 12, wherein the connection portion comprises a foam material that is denser than the foam of the cushioning component.
14. The respiratory mask of claim 13, wherein the foam of the connection portion has an air permeability in the range of 0-5 L/m /s.
15. The respiratory mask of any one of claims 13 and 14, wherein the foam of the connection portion has a density in the range of 100-500 kg/m .
16. The respiratory mask of any one of claims 13 to 14, wherein the foam of the connection portion has an IFD hardness at 40% compression in the range of 10 to 100N.
17. The respiratory mask of any one of claims 1 to 16, wherein, in a cross- sectional view, the cushioning component has a rectangular, trapezoidal or triangular shape. James & Wells Ref: 505071DIV5
18. The respiratory mask of any one of claims 1 to 16, wherein the cushioning component has a triangular cross-section and includes: an inner side facing the center of the mask; an outer side facing away from the center of the mask; and a base side, which includes the cushioning component attachment surface, that is arranged to face the connection portion attachment surface.
19. The respiratory mask of claim 18, wherein, in a cross-sectional view, a length of the outer side of the cushioning component is greater than a length of the inner side of the cushioning component, to facilitate a / the rolling-in effect.
20. The respiratory mask of any one of claims 1 to 19, wherein a portion of the cushioning component has an outer surface which has positive curvature in two directions thus forming at least a partial dome.
21. The respiratory mask of any one of claims 1 to 20, wherein the angle of the connection portion attachment surface in the radial direction of the interfacing structure varies in at least a / the cheek region and / or a / the lip region of the interfacing structure.
22. The respiratory mask of any one of claims 1 to 21, wherein the cushioning component in a / the nasal bridge region of the interfacing structure has a raised profile relative to an adjacent cheek region of the cushioning component.
23. The respiratory mask of any one of claims 1 to 22, wherein the connection portion is more rigid than the cushioning component.
24. A cushion for a respiratory mask to provide a supply of pressurized air to the entrance of the airways of a patient for treatment of sleep disordered breathing, comprising: an interfacing structure comprising a connection portion, and a cushioning component, James & Wells Ref: 505071DIV5 the connection portion being of reduced hardness or increased flexibility compared to a frame of a respiratory mask to which the connection portion in use attaches, the cushioning component being at least partially constructed from a foam material and being configured to directly engage and form a seal with a region of the patient’s face in the vicinity of an entrance to the patient’s airways, wherein an interior of the interfacing structure at least partially forms a cavity to receive at least a portion of the patient’s nose in use, wherein a connection portion attachment surface of the connection portion is joined to a cushioning component attachment surface of the cushioning component, wherein at least one of the following parameters of the interfacing structure varies around a perimeter of the interfacing structure and at least contributes to a roll- in effect of the cushioning component: 1) an amount of offset between an inner edge of the connection portion attachment surface and an inner edge of the cushioning component attachment surface; 2) a cross-sectional profile of the connection portion; 3) an offset of an apex of a cross-sectional profile of the cushioning component; and 4) an angle of the connection portion attachment surface in a radial direction of the interfacing structure.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NZ770159A NZ770159A (en) | 2008-09-12 | 2009-09-03 | A foam-based interfacing structure method and apparatus |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2008904769A AU2008904769A0 (en) | 2008-09-12 | A Foam-Based Interfacing Structure Method and Apparatus | |
AU2008904769 | 2008-09-12 | ||
AU2008904778A AU2008904778A0 (en) | 2008-09-15 | A Foam-Based Interfacing Structure Method and Apparatus | |
AU2008904778 | 2008-09-15 | ||
NZ738034A NZ738034A (en) | 2008-09-12 | 2009-09-03 | A foam-based interfacing structure method and apparatus |
Publications (2)
Publication Number | Publication Date |
---|---|
NZ754381A NZ754381A (en) | 2020-12-18 |
NZ754381B2 true NZ754381B2 (en) | 2021-03-19 |
Family
ID=
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