U.S. patent application number 14/136163 was filed with the patent office on 2015-02-19 for cushion for patient interface.
This patent application is currently assigned to ResMed Limited. The applicant listed for this patent is ResMed Limited. Invention is credited to Aaron Samuel DAVIDSON, Matthew EVES, Robin Garth HITCHCOCK, Susan Robyn LYNCH, David John WORBOYS.
Application Number | 20150047643 14/136163 |
Document ID | / |
Family ID | 36677304 |
Filed Date | 2015-02-19 |
United States Patent
Application |
20150047643 |
Kind Code |
A9 |
DAVIDSON; Aaron Samuel ; et
al. |
February 19, 2015 |
CUSHION FOR PATIENT INTERFACE
Abstract
A cushion for a patient interface that delivers breathable gas
to a patient includes a base wall structured to be connected to a
frame, an underlying support cushion extending away from the base
wall towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane is adapted to form a continuous seal on the patient's
face. The underlying cushion has a spring-like connection with the
base wall. The underlying cushion and/or base wall define a spring
constant that varies along a length of the seal.
Inventors: |
DAVIDSON; Aaron Samuel;
(Sydney, AU) ; HITCHCOCK; Robin Garth; (Sydney,
AU) ; EVES; Matthew; (Sydney, AU) ; WORBOYS;
David John; (Jilliby, AU) ; LYNCH; Susan Robyn;
(Maitland, AU) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ResMed Limited |
Bella Vista |
|
AU |
|
|
Assignee: |
ResMed Limited
Bella Vista
AU
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20140144449 A1 |
May 29, 2014 |
|
|
Family ID: |
36677304 |
Appl. No.: |
14/136163 |
Filed: |
December 20, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13688931 |
Nov 29, 2012 |
8613281 |
|
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14136163 |
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13537876 |
Jun 29, 2012 |
8485192 |
|
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13688931 |
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|
11793981 |
Jun 25, 2007 |
8220459 |
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PCT/AU06/00032 |
Jan 12, 2006 |
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13537876 |
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60643130 |
Jan 12, 2005 |
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60724303 |
Oct 7, 2005 |
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Current U.S.
Class: |
128/206.24 |
Current CPC
Class: |
A61M 16/06 20130101;
A61M 16/0611 20140204; A62B 18/08 20130101; Y10T 29/49 20150115;
A61M 16/0616 20140204; A61M 16/0622 20140204 |
Class at
Publication: |
128/206.24 |
International
Class: |
A61M 16/06 20060101
A61M016/06 |
Claims
1-20. (canceled)
21. A cushion for a patient interface that delivers breathable gas
to a patient, the cushion including at least a nasal bridge region,
a side of nose region, an upper cheek region and a lower cheek
region, the cushion comprising: a base wall structured to be
connected to a frame; an underlying cushion extending away from the
base wall towards the patient's face when the cushion is worn; and
a membrane provided to substantially cover at least a portion of
the underlying cushion, the membrane including at least a nasal
bridge region and a side of nose region adapted to form a
continuous seal on a nasal bridge region and a side of nose region
of the patient's face, respectively, wherein the cushion has a
spring configuration such that the underlying cushion is configured
to move with respect to the base wall in accordance with a spring
characteristic of the spring configuration and apply a spring force
against the membrane when a force by the frame is applied to the
underlying cushion when the cushion is worn, and wherein a lateral
component of the spring characteristic is relatively more stiff in
the side of nose region of the cushion and relatively less stiff in
the lower cheek region of the cushion.
22. The cushion according to claim 21, wherein the membrane also
includes an upper cheek region, a lower cheek region and a chin
region adapted to form a continuous seal on an upper cheek region,
a lower cheek region, and a chin region of the patient's face when
the cushion is worn.
23. The cushion according to claim 22, wherein the cushion has a
relatively more stiff spring characteristic in the side of nose
region and a relatively less stiff spring characteristic in the
upper cheek region.
24. The cushion according to claim 21, wherein the underlying
cushion is configured such that, when the cushion is worn, a
lateral component of the spring force in the side of nose region of
the cushion is greater than a lateral component of the spring force
in the lower cheek region of the cushion.
25. The cushion according to claim 21, wherein the underlying
cushion in the side of nose region of the cushion is angled with
respect to a bottom of the frame and thereby configured to cause
the spring force against the membrane in the side of nose region of
the cushion to be substantially perpendicular to the patient's skin
surface in the side of nose region of the patient's face when the
cushion is worn.
26. The cushion according to claim 25, wherein the underlying
cushion in the side of nose region of the cushion is angled in the
range of about 15-30 degrees with respect to the bottom of the
frame.
27. The cushion according to claim 26, wherein the underlying
cushion in the side of nose region of the cushion is angled about
22 degrees with respect to the bottom of the frame.
28. The cushion according to claim 21, wherein the spring force in
the side of nose region of the cushion is directed at an angle with
respect to the spring force in the lower cheek region of the
cushion.
29. The cushion according to claim 21, wherein the spring force in
the side of nose region of the cushion is directed at an angle with
respect to the spring force in the upper cheek region of the
cushion.
30. A cushion for a patient interface that delivers breathable gas
to a patient, the cushion including a nasal bridge region, the
cushion comprising: a base wall structured to be connected to a
frame; an underlying cushion extending away from the base wall
towards the patient's face when the cushion is worn; and a membrane
provided to substantially cover at least a portion of the
underlying cushion, the membrane including a nasal bridge region
and a chin region adapted to form a continuous seal on a nasal
bridge region of the patient's face, respectively, wherein the
cushion has a spring configuration such that the underlying cushion
is configured to move with respect to the base wall in accordance
with a spring characteristic of the spring configuration and apply
a spring force against the membrane when a force by the frame is
applied to the underlying cushion when the cushion is worn, and
wherein a lateral component of the spring characteristic is
relatively more stiff in a first portion of the cushion that is
relatively proximal the nasal bridge region of the cushion and
relatively less stiff in a second portion of the cushion that is
relatively distal the nasal bridge region of the cushion when the
cushion is worn.
31. The cushion according to claim 30, wherein the underlying
cushion is configured such that, when the cushion is worn, a
lateral component of the spring force in the first portion of the
cushion is greater than a lateral component of the spring force in
the second portion of the cushion.
32. The cushion according to claim 30, wherein the membrane also
includes a side of nose region, an upper cheek region, a lower
cheek region and a chin region adapted to form a continuous seal on
a side of nose region, an upper cheek region, a lower cheek region,
and a chin region of the patient's face when the cushion is worn,
and wherein the first portion of the cushion is a side of nose
region and the second portion of the cushion is an upper check
region and/or a lower check region.
33. The cushion according to claim 32, wherein the cushion has a
relatively more stiff spring characteristic in the side of nose
region and a relatively less stiff spring characteristic in the
lower cheek region.
34. The cushion according to claim 32, wherein the underlying
cushion in the side of nose region of the cushion is angled with
respect to a bottom of the frame and thereby configured to cause
the spring force against the membrane in the side of nose region of
the cushion to be substantially perpendicular to the patient's skin
surface in the side of nose region of the patient's face when the
cushion is worn.
35. The cushion according to claim 34, wherein the underlying
cushion in the side of nose region of the cushion is angled in the
range of about 15-30 degrees with respect to the bottom of the
frame.
36. The cushion according to claim 35, wherein the underlying
cushion in the side of nose region of the cushion is angled about
22 degrees with respect to the bottom of the frame.
37. The cushion according to claim 32, wherein the spring force in
the side of nose region of the cushion is directed at an angle with
respect to the spring force in the lower cheek region of the
cushion.
38. The cushion according to claim 32, wherein the spring force in
the side of nose region of the cushion is directed at an angle with
respect to the spring force in the upper cheek region of the
cushion.
Description
CROSS-REFERENCE TO APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No.
13/688,931, filed Nov. 29, 2012, pending, which is a continuation
of U.S. Ser. No. 13/537,876, filed Jun. 29, 2012, now U.S. Pat. No.
8,485,192, which is a continuation of U.S. Ser. No. 11/793,981,
filed Jun. 25, 2007, now U.S. Pat. No. 8,220,459, which is the US
national phase of international application PCT/AU2006/000032,
filed 12 Jan. 2006, which designated the U.S. and claims the
benefit of U.S. Provisional Application Nos. 60/643,130, filed Jan.
12, 2005, and 60/724,303, filed Oct. 7, 2005, each of which is
hereby incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a cushion for a patient
interface, the patient interface being used in the treatment, e.g.,
of Sleep Disordered Breathing (SDB) with Non-Invasive Positive
Pressure Ventilation (NPPV).
BACKGROUND OF THE INVENTION
[0003] The use of NPPV for treatment of SDB such as Obstructive
Sleep Apnea (OSA) was pioneered by Sullivan (see U.S. Pat. No.
4,944,310). Apparatus for the treatment of SDB involves a blower
which delivers a supply of air at positive pressure to a patient
interface via a conduit. The patient interface may take several
forms, such as a nasal mask assembly and a nasal and mouth mask
assembly. Patients typically wear a mask assembly while sleeping to
receive the NPPV therapy.
[0004] Mask assemblies typically comprise a rigid shell or frame
and a soft face-contacting cushion. The cushion spaces the frame
away from the patient's face. The frame and cushion define a cavity
which receives the nose or nose and mouth. The frame and cushion
are held in position on the patient's face by a headgear assembly.
The headgear assembly typically comprises an arrangement of straps
which pass along both sides of the patient's face to the back or
crown of the patient's head.
[0005] U.S. Pat. No. 5,243,971 (Sullivan and Bruderer) describes a
nasal mask assembly for Continuous Positive Airway Pressure (CPAP)
having a ballooning/molding seal that conforms with the patient's
nose and facial contours. The mask assembly has a face-contacting
portion mounted to a shell which is sized and shaped to overfit the
nose region of the patient. The face-contacting portion is in the
form of a distendable membrane which is molded from an elastic
plastic material. The distendable membrane and the shell together
define a chamber. Pressurized gas admitted to the chamber causes
the membrane to distend outwardly from the patient's face. The
contents of this patent are hereby incorporated by reference.
[0006] U.S. Pat. No. 6,112,746 (Kwok et al.) describes a nasal mask
assembly and a mask cushion therefor. The contents of this patent
are hereby incorporated by reference. The cushion comprises a
substantially triangularly-shaped frame from which extends a
membrane. The frame has an edge by which the cushion is affixed to
a mask body. The membrane has an aperture into which the patient's
nose is received. The membrane is spaced away from the rim of the
frame, and its outer surface is of substantially the same shape as
the rim.
[0007] The cushion of a patient interface can play a key role in
the comfort and effectiveness of therapy. There is considerable
variation in facial size and shape which can mean that a mask
designed for one type of face may not be suitable for another. For
example, an Asian-type nose tends to have a lower nasal bridge
whereas a Caucasian-type nose has a higher nasal bridge. Using the
wrong cushion can lead to excessive leak and discomfort. While
creating customized cushions for every patient may solve some
fitting issues, customized masks are very expensive. Thus,
manufacturers seek to develop cushions which provide a comfortable
and effective seal for a range of facial sizes and shapes.
SUMMARY OF THE INVENTION
[0008] One aspect of the invention is to provide a patient
interface having a cushion that provides more comfort to the
patient while maintaining an effective seal.
[0009] Another aspect of the invention is to provide a comfortable
cushion for a patient interface which fits a wide range of facial
shapes and sizes.
[0010] Another aspect of the invention relates to a cushion
including an underlying cushion and a membrane, wherein the
underlying cushion and the membrane have a substantially flat
portion in a nasal region of the cushion.
[0011] Another aspect of the invention relates to a cushion
including a base wall, an underlying cushion and a membrane,
wherein the base wall and underlying cushion have a cross-sectional
configuration that provides a variable spring constant around the
perimeter of the cushion.
[0012] Another aspect of the invention relates to a patient
interface wherein the base wall and the frame connection of the
cushion are internally offset with respect to the most external
cushion point, e.g., external membrane surface.
[0013] Another aspect of the invention relates to a cushion
including a base wall and underlying cushion that are inclined or
angled in a side of nose region of the cushion.
[0014] Another aspect of the invention relates to a cushion having
a substantially constant mouth width irrespective of its face
height.
Another aspect of the invention relates to a cushion for a patient
interface that delivers breathable gas to a patient. The cushion
includes a base wall structured to be connected to a frame, an
underlying support cushion extending away from the base wall
towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane includes nasal bridge, cheek, and chin regions adapted
to form a continuous seal on nasal bridge, cheek, and chin regions
of the patient's face, respectively. The nasal bridge region and
adjacent two cheek regions define an intersection or apex. The
membrane in the nasal bridge region has a height at the apex or
intersection that is greater than a height in an adjacent portion
of the cheek region.
[0015] Another aspect of the invention relates to a cushion for a
patient interface that delivers breathable gas to a patient. The
cushion includes a base wall structured to be connected to a frame,
an underlying support cushion extending away from the base wall
towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane is adapted to form a continuous seal on the patient's
face. The underlying cushion has a spring-like connection with the
base wall. The underlying cushion and/or base wall define a spring
constant that varies along a length of the seal.
[0016] Another aspect of the invention relates to a cushion for a
patient interface that delivers breathable gas to a patient. The
cushion includes a base wall structured to be connected to a frame,
an underlying support cushion extending away from the base wall
towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane is adapted to form a continuous seal on the patient's
face. One of the membrane and the underlying cushion includes an
external surface that defines an outer width of the cushion, and
the base wall is internally offset with respect to the external
surface.
[0017] Yet another aspect of the invention relates to a cushion for
a patient interface that delivers breathable gas to a patient. The
cushion includes a base wall structured to be connected to a frame,
an underlying support cushion extending away from the base wall
towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane includes at least nasal bridge and side of nose
regions adapted to form a continuous seal on nasal bridge and side
of nose regions of the patient's face, respectively. The base wall
and the underlying cushion in the side of nose region are inclined
or angled with respect to a bottom of the frame.
[0018] Yet another aspect of the invention relates to a cushion for
a patient interface that delivers breathable gas to a patient. The
cushion includes a base wall structured to be connected to a frame,
an underlying support cushion extending away from the base wall
towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane includes nasal bridge, side of nose, upper cheek,
lower cheek and chin regions adapted to form a continuous seal on
nasal bridge, side of nose, upper cheek, lower cheek, and chin
regions of the patient's face, respectively. An inner edge of the
membrane defines an aperture that receives the patient's nose and
mouth. A lower portion of the aperture that receives the patient's
mouth has a mouth width that remains substantially constant
irrespective of a face height of the cushion.
[0019] Yet another aspect of the invention relates to a cushion for
a patient interface that delivers breathable gas to a patient. The
cushion includes a base wall structured to be connected to a frame,
an underlying support cushion extending away from the base wall
towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane is adapted to form a continuous seal on the patient's
face. At least a portion of the underlying cushion and/or base wall
has a lower portion including a spring configuration that defines
displacement of the cushion with respect to a force applied from
the frame.
[0020] Still another aspect of the invention relates to a method of
designing a series of mask assemblies. The method includes
providing a first cushion adapted to fit a larger range of patients
and providing a second cushion adapted to fit a smaller range of
patients. Each of the first and second cushions includes an
aperture that receives at least the patient's mouth. The aperture
of the first and second cushions have the same width.
[0021] Still another aspect of the invention relates to a cushion
for a patient interface that delivers breathable gas to a patient.
The cushion includes a base wall structured to be connected to a
frame, an underlying support cushion extending away from the base
wall towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane includes at least a nasal bridge region adapted to
form a continuous seal on a nasal bridge region of the patient's
face. The membrane forms an elongated ridge in the nasal bridge
region. The elongated ridge has sloping sides that meet to form an
elongated crest. Each of the sloping sides is angled from a crest
centerline in the range of 30-60.degree. and the crest has a radius
of curvature in the range of 1.0-5.0 mm.
[0022] Still another aspect of the invention relates to a cushion
for a patient interface that delivers breathable gas to a patient.
The cushion includes a base wall structured to be connected to a
frame, an underlying support cushion extending away from the base
wall towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane includes at least a nasal bridge region adapted to
form a continuous seal on a nasal bridge region of the patient's
face. The nasal bridge region of the membrane includes a contoured
portion that curves inwardly towards a cavity of the cushion along
a radius to terminate at an inner edge of the membrane. The
contoured portion has a free end that is angled with respect to a
face contacting plane of the cushion in the range of
30-50.degree..
[0023] Still another aspect of the invention relates to a cushion
for a patient interface that delivers breathable gas to a patient.
The cushion includes a base wall structured to be connected to a
frame, an underlying support cushion extending away from the base
wall towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane is adapted to form a continuous seal on the patient's
face. The underlying cushion and/or base wall has a question-mark
or sickle shape.
[0024] Still another aspect of the invention relates to a cushion
for a patient interface that delivers breathable gas to a patient.
The cushion includes a base wall structured to be connected to a
frame, an underlying support cushion extending away from the base
wall towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane is adapted to form a continuous seal on the patient's
face. The underlying cushion has an arcuate configuration including
an arc length greater than 16 mm.
[0025] Still another aspect of the invention relates to a cushion
for a patient interface that delivers breathable gas to a patient.
The cushion includes a base wall structured to be connected to a
frame, an underlying support cushion extending away from the base
wall towards the patient's face in use, and a membrane provided to
substantially cover at least a portion of the underlying cushion.
The membrane is adapted to form a continuous seal on the patient's
face. The membrane includes a thickness that varies along a length
of the seal.
[0026] Still another aspect of the invention relates to a cushion
for a patient interface that delivers breathable gas to a patient.
The cushion includes a base wall structured to be connected to a
frame and a membrane adapted to form a continuous seal on the
patient's face. At least a portion of the base wall includes a
tapered portion that tapers towards the membrane.
[0027] Still another aspect of the invention relates to a mask
system including a set of at least two cushions arranged to suit
different face sizes, wherein the at least two cushions have
substantially the same width.
[0028] 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
[0029] The accompanying drawings facilitate an understanding of the
various embodiments of this invention. In such drawings:
[0030] FIGS. 1-9 illustrate a cushion for a patient interface
constructed according to an embodiment of the present invention and
showing exemplary dimensions of an embodiment;
[0031] FIGS. 10-14 are cross-sectional views through the cushion
shown in FIG. 5;
[0032] FIG. 15 is a front view of the cushion shown in FIGS. 1-9
that illustrates various regions of the cushion;
[0033] FIGS. 16-17 illustrates another size of the cushion shown in
FIGS. 1-9;
[0034] FIGS. 18-19 illustrates yet another size of the cushion
shown in FIGS. 1-9;
[0035] FIGS. 20-21 illustrates still another size of the cushion
shown in FIGS. 1-9;
[0036] FIG. 22 is a cross-sectional view through the cushion shown
in FIGS. 1-9 that illustrates parameters that can modify a spring
characteristic of the underlying cushion;
[0037] FIGS. 23-29 are cross-sectional views through the cushion
shown in FIG. 15 and showing exemplary parameters of an embodiment,
the cross-sectional views illustrating the underlying cushion
only;
[0038] FIGS. 30A-30N are cross-sectional views illustrating
alternative embodiments of a cushion according to the present
invention;
[0039] FIG. 31-32 are graphs illustrating the general relationship
between Force and Displacement for embodiments of the cushion shown
in FIGS. 1-9 and a known cushion commercially sold under the name
of UltraMirage.RTM. Full Face by ResMed. Ltd.;
[0040] FIG. 33 is a graph illustrating the general relationship
between Force and Displacement for various cross-sections of the
cushion shown in FIGS. 23-29;
[0041] FIG. 34A illustrates a spring length for the cushion shown
in FIGS. 1-9, and showing exemplary dimensions of an embodiment
according to the present invention;
[0042] FIG. 34B illustrates a spring length for a known cushion
commercially sold under the name of UltraMirage.RTM. Full Face by
ResMed. Ltd., and showing exemplary dimensions of the
UltraMirage.RTM. Full Face;
[0043] FIG. 35 is a side view of the cushion shown in FIGS.
1-9;
[0044] FIGS. 36-37 are cross-sectional views through the cushion
shown in FIG. 35;
[0045] FIG. 38 is a front view of the cushion shown in FIGS. 1-9
illustrating a flat portion thereof;
[0046] FIG. 38B is a graph illustrating the general relationship
between Force and Displacement in a nasal bridge region for
embodiments of the cushion shown in FIGS. 1-9 and a known cushion
commercially sold under the name of UltraMirage.RTM. Full Face mask
by ResMed. Ltd.;
[0047] FIGS. 39-40B are front and cross-sectional views of an
embodiment of the cushion shown in FIGS. 1-9, and showing exemplary
dimensions of an embodiment according to the present invention;
[0048] FIGS. 41-45 are perspective views of an embodiment of the
cushion shown in FIGS. 1-9 illustrating the rolling action of the
nasal bridge region in use;
[0049] FIGS. 46-53 illustrate a known cushion commercially sold
under the name of UltraMirage.RTM. Full Face by ResMed. Ltd.;
[0050] FIGS. 54-58 illustrate a cushion for a patient interface
according to another embodiment of the present invention and
showing exemplary dimensions of an embodiment;
[0051] FIGS. 59-63 are cross-sectional views through the cushion
shown in FIG. 54;
[0052] FIG. 64 is a cross-sectional view of a portion of the
cushion shown in FIGS. 54-58 (in solid lines) overlaid with a
cross-section of a known cushion commercially sold under the name
of UltraMirage.RTM. Full Face by ResMed. Ltd. (only relevant
portions of the UltraMirage.RTM. cushion may be shown in dashed
lines, i.e., there may be other different portions not shown);
[0053] FIG. 65 is a cross-sectional view of a portion of the
cushion shown in FIGS. 54-58 showing exemplary dimensions of an
embodiment according to the present invention;
[0054] FIGS. 66-69 are cross-sectional views through the cushion
shown in FIG. 54, and showing exemplary dimensions of an embodiment
according to the present invention;
[0055] FIGS. 70-71 are plan and cross-sectional views,
respectively, of the cushion shown in FIG. 54, and showing
exemplary dimensions of an embodiment according to the present
invention;
[0056] FIGS. 72-76 illustrate a cushion for a patient interface
according to another embodiment of the present invention;
[0057] FIGS. 77-83 illustrate a cushion for a patient interface
according to another embodiment of the present invention;
[0058] FIGS. 84-90 illustrate a cushion for a patient interface
according to another embodiment of the present invention;
[0059] FIG. 91 illustrates an alternative cushion cross-section to
that shown in FIG. 34A;
[0060] FIG. 92 illustrates another alternative cushion
cross-section to that shown in FIG. 34A;
[0061] FIG. 93 illustrates an alternative cushion arrangement to
that shown in FIG. 15;
[0062] FIGS. 94A-94C are a set of views depicting a horizontal
cross-section through the nasal bridge region of the cushion of
FIG. 35; and
[0063] FIGS. 95A-95C are a set of views depicting a horizontal
cross-section through the nasal bridge region of the prior art
cushion of FIG. 51.
DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS
[0064] FIGS. 1-14 illustrate a cushion 10 constructed according to
an embodiment of the present invention. The cushion 10 is adapted
to be removably or permanently connected (e.g., via mechanical
and/or adhesive fastening) to a frame of a patient interface
structured to deliver breathable gas to a patient. In an
embodiment, the cushion 10 may be co-molded to a frame of a patient
interface. In another embodiment, the cushion may form part of a
frame with an outer support structure, e.g., ResMed's Hospital
Nasal Mask. The cushion 10 provides a seal with the patient's face
during use.
[0065] In the illustrated embodiment, the cushion 10 forms a part
of a full-face mask. Specifically, the cushion 10 provides a seal
around the patient's nose and mouth to enable the delivery of
breathable gas to the patient's nose and mouth. However, aspects of
the present invention may be applicable to other breathing
arrangements, e.g., a nasal mask, a mouth mask, etc. The cushion 10
may be used with a gusset as described in U.S. patent application
Ser. No. 10/655,622, incorporated herein by reference in its
entirety.
[0066] The cushion 10 is structured to provide a more comfortable
fit for a wide range of facial shapes and sizes. Also, the cushion
10 is structured to provide a better seal and reduce the risk of
leakage as discussed below.
[0067] As illustrated in FIGS. 1-14, the cushion 10 includes a
non-face-contacting portion 12 structured to be connected to a
frame of the patient interface, e.g., via a friction-fit, a
tongue-and-groove arrangement, etc., and a face-contacting portion
14 structured to engage the patient's face.
[0068] As best shown in FIGS. 5 and 15, the face-contacting portion
14 of the cushion 10 preferably has a generally triangular shape
and is structured to continuously contact nasal bridge, side of
nose, upper cheek, lower cheek, and chin regions of the patient.
However, the face-contacting portion 14 may have other suitable
shapes, e.g., a generally trapezoidal shape. In the illustrated
embodiment, as best shown in FIG. 15, the cushion 10 includes a
nasal bridge region 16 to provide a seal along the patient's nasal
bridge, a pair of cheek regions 15 to provide a seal along the
patient's nose, cheek, and mouth, and a chin region 20 to provide a
seal along the patient's chin. The pair of cheek regions 15 may be
further defined as a pair of side of nose regions 17 to provide a
seal along the sides of the patient's nose, a pair of upper cheek
regions 18 to provide a seal along upper cheeks of the patient, and
a pair of lower cheek regions 19 to provide a seal along the
patient's lower cheeks and the sides of the patient's mouth.
Width of Cushion in Lower Cheek Regions and Ratio of Face Width to
Height Across Mask Sizes
[0069] The cushion 10 may be provided in various sizes in order to
accommodate various facial sizes. For example, FIGS. 16-21
illustrate embodiments of the cushion 10 in three other sizes. In
an embodiment, the cushion 210 shown in FIGS. 16-17 may represent a
extra small size, the cushion 310 shown in FIGS. 18-19 may
represent a small size, the cushion 10 shown in FIGS. 1-14 may
represent a medium size, and the cushion 410 shown in FIGS. 20-21
may represent a large size. As illustrated, the mouth widths w3,
w1, w2 and w4 of the cushions 10, 210, 310, 410 are substantially
constant irrespective of their face heights h3, h1, h2 and h4.
[0070] Specifically, the cushion 10 defines an aperture 22 that
receives the patient's mouth. In a preferred embodiment, the lower
portion of the aperture 22 has a constant width for all cushion
sizes, e.g., 60 mm. However, the width of the lower portion of the
aperture 22 may be almost constant, e.g., in a range of 5 mm, for
all cushion sizes. For example, the width of the lower portion of
the aperture 22 of the cushion 10 may be 60 mm.+-.5. In contrast,
the width of the lower portion of the aperture 722 of a known
cushion 700 commercially sold under the name of UltraMirage.RTM.
Full Face by ResMed. Ltd. is 60 mm for a large size, 54 mm for a
medium size, and 52 mm for a small size. The UltraMirage.RTM.
cushion 700 is shown in FIGS. 46-53.
[0071] Anthropometric data has indicated that mouth widths for
patients with relatively small faces are not necessarily narrower
than mouth widths for patients with relatively large faces. Hence,
all faces generally have the same mouth width. Thus, the aperture
22 in the cushion 10 is made sufficiently wide to accommodate a
wide range of patients and remains constant or almost constant,
e.g., a range of 5 mm, regardless of the change in face height of a
mask to fit larger faces. This can be seen in the substantially
constant cushion geometry around the lower cheek and chin regions
of the different cushion sizes, and thus the varying width to
height ratios of the different cushion sizes. For example, the
lower portion of the aperture 22 of each of the cushions 10, 210,
310, 410 has substantially the same width.
Base Wall, Underlying Cushions, and Membrane
[0072] As best shown in FIGS. 9 and 10-14, the face-contacting
portion 14 of the cushion 10 includes a base wall 28, a pair of
underlying support cushions 30 extending away from the base wall
28, and a membrane 32 provided to substantially cover at least a
portion of the underlying cushions 30 and provide a sealing
structure for the face contacting portion 14. The base wall 28 and
underlying cushions 30 provide a support structure for the membrane
32.
[0073] As illustrated, the underlying cushions 30 are preferably
provided on lateral sides of the base wall 28 only, e.g., in the
side of nose, upper cheek, and lower cheek regions 17, 18, 19,
although the underlying cushions 30 could be joined and
substantially surround the patient's nose and also the lower lip or
chin region. The underlying cushions 30 add rigidity to the
membrane 32 at the sides of the patient's mouth and cheeks. While
it is preferable that the membrane 32 be thinner than the
underlying cushions 30, they could have the same thickness or the
membrane could be thicker than the underlying cushion. Also, the
elimination of an underlying cushion in the chin region 20 allows
the cushion 10 to more deeply engage with the patient's face in
this region without subjecting the patient's chin region 20 to
excessive pressure. That is, there is no underlying cushion to
restrain the movement of the membrane 32 in this region, which may
improve the seal in this region and adjacent regions. Additionally,
the elimination of an underlying cushion in the chin region 20
enables the cushion 10 to accommodate more facial shapes and
provides more flexibility and allows for movement or opening of the
mouth.
[0074] In the illustrated embodiment, the face-contacting portion
14 of the cushion has a double-walled construction, i.e., membrane
32 and underlying cushion 30, in the side of nose, upper cheek, and
lower cheek regions 17, 18, 19, and a single-walled construction,
i.e., membrane 32, in the nasal bridge and chin regions 16, 20 as
shown in FIGS. 10-14. The single wall construction at the top and
bottom of the cushion 10 helps to accommodate high landmarks, e.g.,
pointed chin, by allowing the center of the cushion 10 to flex.
This flexibility accommodates more patients with the same cushion.
However, the cushion 10 may have any other suitable construction,
e.g., single walled, double walled, triple walled or more walled
construction, in any suitable region of the cushion 10, e.g.,
cheek, chin, nasal bridge. For example, the underlying cushion 30
may extend around the entire perimeter of the cushion 10. Also, the
underlying cushion 30 could be completely removed.
[0075] As shown in FIGS. 10-14, the membrane thickness may vary in
the different regions of the cushion 10. As illustrated, the
membrane in the nasal bridge region 16 and upper cheek region 18 is
0.3 mm thick which transitions to 0.5 mm thickness in the upper
cheek region 18 and maintains this thickness in the lower cheek and
chin regions 19, 20. This arrangement provides greater
compliance/stretch across the nasal bridge by providing a thinner
membrane. This stretch is not required at the lower regions and
here the thicker membrane is less likely to vibrate on the patient
face in use.
Internally Offset Base Wall and Frame Connection
[0076] Another aspect of the invention relates to the size and
configuration of the base wall 28, underlying cushion 30, and
membrane 32 of the cushion 10. FIGS. 48-50 illustrate the base wall
728, underlying cushion 730, and membrane 732 of the
UltraMirage.RTM. cushion 700. As illustrated, the cushion 10 has a
different cross-sectional profile than the UltraMirage.RTM. cushion
700.
[0077] For example, as best shown in FIGS. 11-13, the base wall 28
and the frame connection 29 are internally offset with respect to
the most external cushion point 39, e.g., external surface of
membrane or underlying cushion. In contrast, the base wall 728 and
frame connection 729 of the UltraMirage.RTM. cushion 700 are not
offset with respect to the most external cushion point 739 (see
FIGS. 48-50). As a result of this inward movement, the base width
of the cushion 10 is narrowed, e.g., by about 5 mm or 2.5 mm per
base, which provides a less obtrusive cushion and saves material
which means less weight and cost. Also, the narrower cushion 10
provides less free length for the cushion 10 to bulge outwardly in
use, thus helping to minimize or eliminate leakage.
[0078] As illustrated, a lower portion of the underlying cushion 30
has a more arcuate, e.g., semi-circular, question-mark,
sickle-shape, configuration that defines a space 34 below a lower
portion of the underlying cushion 30 and adjacent the base wall
28.
[0079] In the illustrated embodiment, the widest or most external
cushion point is the external surface of the underlying cushion 30
and the base wall 28 and frame attachment 29 are offset internally
with respect to this. Thus, by the design of the cushion 10 and in
particular the underlying cushion curvature, the frame is attached
at a narrower point and thus the frame itself is narrower. This
arrangement has significant advantages in terms of the frame
weight, perceived bulk, and size. This arrangement may also
minimize the dead space within the mask which will help to reduce
CO.sub.2 rebreathing.
[0080] Moreover, the space 34 below the underlying cushion 30
allows a greater range of movement of the underlying cushion 30 to
add more flexibility to the underlying cushion 30 and hence the
membrane 32 in use. Specifically, the space 34 below the underlying
cushion 30 enables more displacement of the underlying cushion 30
using substantially the same space restraints as the
UltraMirage.RTM. cushion 700, for example. Additionally, the space
34 allows more displacement of the underlying cushion 30 before
bottoming out, therefore reducing discomfort. Thus, this
arrangement provides a more gradual force, improves comfort, and
allows a wider range of patients to achieve seal.
Variable Spring Constant
[0081] As illustrated, the underlying cushion 30 has a spring-like
connection with the base wall 28 such that the underlying cushion
30 can move with respect to the base wall 28. That is, the
underlying cushion 30 is movable into the space 34 (the underlying
cushion 30 is also movable into the space 33). Thus, a spring force
is provided when a frame force is applied and the underlying
cushion 30 is resiliently moved back into its initial position when
the frame force is released. The underlying cushion 30 and/or base
wall 28 may have any suitable spring constant, and the spring
constant may be varied anywhere along its length, e.g., by tapering
and/or varying the thickness of the base wall 28, varying the
thickness of intermediate and/or lower portions of the underlying
cushion 30. Also, the spring-like connection may extend along the
whole underlying cushion 30 or the spring-like connection may be
localized in certain regions such as the cheekbone region.
[0082] Thus, a spring characteristic is molded with the base wall
28 and underlying cushion 30 of the cushion 10 which allows a
continuously variable spring constant to be incorporated into the
base wall 28 and underlying cushion 30, e.g., the wall stiffness
can be varied at each cushion region to suit the sealing
requirements in each region which may vary due to the underlying
facial structure of the patient.
[0083] The spring characteristics of the base wall 28 and
underlying cushion 30 may be modified by varying a number of
characteristics shown in FIG. 22. For example, the spring
characteristics may be modified by varying the underlying cushion
height h, the thickness t, the radius r, and the underlying cushion
offset c. It is to be understood that these parameters are merely
exemplary, and other parameters may be varied to modify the spring
characteristics of the base wall 28 and underlying cushion 30.
[0084] FIGS. 23-29 illustrate parameters of an embodiment of the
underlying cushion 30 and base wall 28 to achieve desired spring
characteristics. As illustrated, the underlying cushion 30 and base
wall 28 is configured to provide a variable spring constant around
the perimeter of the cushion 10. That is, the spring constant of
the underlying cushion 30 and base wall 28 differs along the side
of nose, upper cheek, and lower cheek regions 17, 18, 19. Although
specific parameters of the cushion 10 are shown in FIGS. 23-29, it
is to be understood that these parameters are merely exemplary and
other parameters are possible depending on application.
[0085] In the nasal bridge region 16 (e.g., see FIG. 10), no
underlying cushion 30 is provided in order to provide high
flexibility and the ability to conform to a variety of facial
shapes. However, in an embodiment, there may be an underlying
cushion 30 with a very soft spring characteristic in this
region.
[0086] In the side of nose regions 17 (see FIGS. 23-24), an
underlying cushion 30 and base wall 28 with a fairly stiff spring
characteristic is provided in order to provide lateral stability to
squeeze the side of the patient's nose and keep the membrane 32 in
contact with the underlying cushion 30. As illustrated, this
arrangement is achieved by a relatively thick underlying cushion,
short height, and tight radius. In an embodiment of the section
shown in FIG. 23, h may be 12 mm, r may be 5 mm, t may be 2-3 mm, b
may be 4 mm, w1 may be 11.5 mm, and w2 may be 8 mm. In an
embodiment of the section shown in FIG. 24, h may be 14 mm, r may
be 6-7 mm, t may be 2.5 mm, b may be 4 mm, w1 may be 11.5 mm, w2
may be 9.5 mm, and a may be 22.degree.. It is to be understood that
these dimensions and ranges are merely exemplary and other
dimensions and ranges are possible depending on application.
[0087] Also, as best shown in FIG. 24, the base wall 28 and
underlying cushion 30 in the side of nose regions 17 have been
rotated by about 22 degrees with respect to the bottom of the
frame. That is, the base wall 28 and underlying cushion 30 are
inclined or angled in the side of nose regions 17 of the cushion
10. This arrangement further increases the lateral stability and
allows the force on the membrane to be applied perpendicular to the
skin surface at the side of the patient's nose. This further helps
to keep the membrane 32 in contact with the patient's skin and
prevent any air leaks. In further embodiments, this angle may vary
from 15 to 30 degrees.
[0088] In the upper cheek regions 18 (see FIGS. 25-26), the
underlying cushion 30 and base wall 28 have a stiffness that is
less than that provided in the side of nose regions 17 but stiffer
than that provided in the lower cheek regions 19 due to the
geometry of the underlying cushion, this is provided to suit the
firmer bone structure of the upper cheeks. In an embodiment of the
section shown in FIG. 25, h may be 12-15 mm, preferably 13.5 mm, r
may be 5 mm, t may be 2 mm, b may be 3 mm, and w1 may be 11.5 mm.
In an embodiment of the section shown in FIG. 26, h may be 12-15
mm, preferably 13.5 mm, r may be 5 mm, t may be 2 mm, b may be 3
mm, and w1 may be 11.5 mm. It is to be understood that these
dimensions and ranges are merely exemplary and other dimensions and
ranges are possible depending on application.
[0089] In the lower cheek regions 19 (see FIGS. 27-29), the
underlying cushion 30 and base wall 28 has a relatively low spring
constant. That is, the underlying cushion 30 in the lower cheek
regions 19 is fairly soft since the fleshy cheek region of the
patient deforms readily to form a seal with the cushion at
relatively low forces. As illustrated, this arrangement is achieved
by a greater height h, larger radii r, and a thinner underlying
cushion wall. In an embodiment of the section shown in FIG. 27, h
may be 14 mm, r1 may be 5 mm, r2 may be 7 mm, t may be 1.5-2 mm, b
may be 3.5 mm, and w1 may be 11.5 mm. In an embodiment of the
section shown in FIG. 28, h may be 16.5 mm, r1 may be 6-7 mm, r2
may be 8 mm, t may be 1.5 mm, b may be 3.5 mm, and w1 may be 11.5
mm. In an embodiment of the section shown in FIG. 29, h may be 17.5
mm, r1 may be 6-7 mm, r2 may be 9-10 mm, t may be 1.5 mm, b may be
3.5 mm, and w1 may be 11.5 mm. It is to be understood that these
dimensions and ranges are merely exemplary and other dimensions and
ranges are possible depending on application.
[0090] In the chin region 20 (see FIG. 14), no underlying cushion
30 is provided, although a very flexible spring region may be used.
The chin region 20 provides an unconstrained membrane region that
allows for lateral movement, mouth opening or movement, and a range
of facial shapes.
[0091] Thus, the cushion 10 may be configured to provide different
vertical and/or lateral stiffness in different regions of the
cushion. For example, the side of nose regions 16, 17 are laterally
stiffer than the other regions in order to provide more lateral
stability at the patient's nose.
Alternative Embodiments of Base Wall and Underlying Cushion
[0092] FIGS. 30A-30N illustrate alternative embodiments of the base
wall 28 and the underlying cushion 30. Each of these embodiments
provides an arrangement that allows flexibility of the underlying
cushion 30 in use. In FIG. 30A, the underlying cushion 30 defines
an enclosed space 60 that may optionally be filled with pressurized
air, foam, gel, or elastomeric material and adapted to dampen
movement of the underlying cushion 30 in use. In FIG. 30B, the
space 34 below the underlying cushion 30 is within the interior of
the breathing cavity. Also, the underlying cushion 30 has an
arcuate shape that curves away from the interior of the breathing
cavity towards the base wall 28. However, the underlying cushion 30
may have any other suitable shape. For example, the underlying
cushion 30 in FIG. 30C has a bulbous shape, which may be solid or
hollow. In FIG. 30D, the underlying cushion 30 has a general
Z-shape. In FIGS. 30E and 30F, the underlying cushion 30 has a
bulbous shape (which may be solid or hollow), and the space 34
below the underlying cushion 30 has a ramped configuration. In
FIGS. 30C, 30E, and 30F, the bulbous shape may optionally be filled
with pressurized air, foam gel, or elastomeric material and adapted
to dampen movement of the underlying cushion 30 in use. In FIG. 30E
the ramped configuration of the space 34 is adapted to direct the
underlying cushion 30 downwardly into the base wall 28 in use, and
in FIG. 30F the ramped configuration of the space 34 is adapted to
direct the underlying cushion 30 inwardly towards the breathing
cavity in use. In FIGS. 30G, 30H, and 30I, the underlying cushion
30 has a general T-shape. Also, in FIGS. 30H and 30I, the base wall
28 defines an enclosed space 62 below the T-shaped underlying
cushion 30. The enclosed space 62 may be optionally filled with
pressurized air, foam, gel, or elastomeric material and adapted to
dampen movement of the underlying cushion 30 in use. Moreover, the
spring constant may be varied by varying the pressure within the
enclosed space 62. Additionally, the lower surface of the space 62
may have a ramped configuration (as shown in FIG. 30H) adapted to
direct the underlying cushion 30 inwardly towards the breathing
cavity in use. The lower surface of the enclosed space 60 in FIG.
30A may also have a ramped configuration for directing the
underlying cushion 30 in use. In FIGS. 30J and 30K, the underlying
cushion 30 has an elongated section length for soft spring
characteristics. FIG. 30L illustrates a single wall construction
with an underlying cushion 30 and no membrane. In FIG. 30M, the
space 34 below the underlying cushion 30 is greatly increased. In
FIG. 30N, a spring construction is provided below the base wall
28.
Displacement Provided by Underlying Cushion
[0093] The space 34 allows more displacement of the underlying
cushion 30 for a predetermined amount of force when compared to the
UltraMirage.RTM. cushion 700. That is, the underlying cushion 30
provides more movement for a given force. For example, FIG. 31
illustrates the general relationship between Force and Displacement
for the cushion 10 and the UltraMirage.RTM. cushion 700. As
illustrated, the curve for the cushion 10 is flatter than the
exponential-type curve of the UltraMirage.RTM. cushion 700. Thus,
the underlying cushion 30 is less stiff and more compliant when
compared to the UltraMirage.RTM. cushion 700. It is noted that the
space 34 could be filled with a gel, silicone or other structure to
vary the spring characteristic that it provides.
[0094] Further, as illustrated in FIG. 31, the point B.sub.10 at
which the cushion 10 is fully compressed or bottomed-out is at a
greater displacement than the point B.sub.700 at which the
UltraMirage.RTM. cushion 700 is bottomed-out. Moreover, the
bottom-out point B.sub.10 occurs at a greater force than the
bottom-out point B.sub.700. Thus, the cushion 10 increases the
force required to bottom-out, and provides a wider range of
adjustment. Additionally, FIG. 31 illustrates an example of maximum
and minimum comfortable sealing forces, which provides an example
force range necessary to achieve seal. As illustrated, the range of
displacement A.sub.10 within this force range for the cushion 10 is
substantially larger than the range of displacement A.sub.700
within this force range for the UltraMirage.RTM. cushion 700. Thus,
the cushion 10 allows a wide range of adjustment or displacement to
achieve seal, and ensures that the sealing force is substantially
less than the bottom-out force so that the cushion does not have to
bottom-out to seal.
[0095] FIG. 32 illustrates another embodiment of the relationship
between Force and Displacement for the cushion 10 and the
UltraMirage.RTM. cushion 700. In this embodiment, the linear
portion of the curve for cushion 10 has a greater slope than the
linear portion of the curve for cushion 10 in FIG. 31. The
difference in slope may be attributed to a difference in spring
constants of respective underlying cushions 30. Thus, the cushion
represented in FIG. 31 provides more displacement for a given force
than the cushion represented in FIG. 32. Also, the curve for the
cushion 10 in FIG. 32 intersects with the curve for the
UltraMirage.RTM. cushion 700, such that the force of cushion 10 is
higher at lower displacement, to ensure a seal, and lower at higher
displacement, to maintain comfort for a longer range of
displacement.
[0096] FIG. 33 illustrates another embodiment of the relationship
between Force and Displacement for the cushion 10. In this
embodiment, typical curves for the different regions of the cushion
10 are shown. Specifically, one curve represents the cross-sections
of FIGS. 23-24 in the side of nose region 17, another curve
represents the cross-sections of FIGS. 25-27 in upper cheek and
lower cheek regions 18, 19, and yet another curve represents the
cross-sections of FIGS. 28-29 in the lower cheek region 19. As
illustrated, the cushion 10 is softer or less stiff in the lower
regions of the cushion 10.
Extended Spring Length of Underlying Cushion
[0097] FIGS. 34A and 34B illustrate the extended length of the
flexible underlying cushion 30 which is used to provide a softer
spring characteristic in selected regions of the cushion 10 when
compared with a typical prior art cushion, e.g., the
UltraMirage.RTM. cushion 700. The length a to b can deform, thus
providing a spring characteristic. As illustrated, the length a to
b of the cushion 10 (FIG. 34A) is considerably longer when compared
to the UltraMirage.RTM. cushion 700 (FIG. 34B) due to the curvature
of the underlying cushion 30. In the illustrated embodiment, the
length a to b of the cushion 10 is 22.84. However, in an
embodiment, the length a to b of the cushion 10 may be in the range
of 16-30, preferably 20-25, most preferably 22-24. In another
embodiment, the length a to b of the cushion 10 may be in the range
of 16-20. The length b to c is fairly rigid and does not deform to
provide a spring characteristic. The added length in the cushion 10
has been achieved by the arcuate shape of the underlying cushion 30
and the space 34 is a result of this shape. This added length adds
flexibility and a greater range of movement to the cushion 10.
FIGS. 30J and 30K illustrate other embodiments for achieving a
longer section length.
Configuration of Membrane in Nasal Bridge Region
[0098] The membrane 32 is structured to form an effective seal
around nasal bridge, side of nose, upper cheek, lower cheek, and
chin regions 16, 17, 18, 19, 20 of a patient. Another aspect of the
invention relates to the configuration of the membrane 32 in the
nasal bridge region 16 of the cushion 10, which has been structured
to improve sealing and comfort in this region.
[0099] Specifically, as shown in a preferred embodiment in FIG. 36
and in an alternative embodiment in FIG. 68, the membrane 32 forms
an elongated ridge 35 in the nasal bridge region 16 wherein sloping
sides 36 meet to form an elongated crest 38. Each of the sloping
sides 36 is angled from the crest centerline in the range of
30-60.degree., preferably about 47.degree.. The crest 38 has a
radius of curvature in the range of 1.0-5.0 mm, preferably about
2.5 mm. As illustrated, the underlying cushion 30 has been
eliminated from beneath the membrane 32 in the nasal bridge region
16, which allows the membrane 32 in this region to freely move
between the underlying cushions 30 provided in the side of nose
regions 17. As discussed in greater detail below, this membrane
configuration allows the creation of a steeply inverted section
upon engagement with the patient's nose, which improves fit,
comfort, and seal in the nasal bridge region 16. In contrast, the
UltraMirage.RTM. cushion 700 is relatively flat in this region (see
FIG. 52).
[0100] As shown in a preferred embodiment in FIG. 37 and in an
alternative embodiment in FIG. 69, the forward end 40 of the
elongated ridge 35 has an arcuate configuration. The forward end 40
is structured to engage the patient's nasal bridge region and has a
radius of curvature in the range of 1.5-7.0 mm, preferably about
4.0 mm.
Sharp Cross-Sectional Profile of Nasal Bridge Region
[0101] As shown in FIG. 10, the membrane 32 in the nasal bridge
region 16 has a sharper cross-sectional profile than the
corresponding portion of the UltraMirage.RTM. cushion 700 (see FIG.
48). Specifically, the membrane 32 provides a large contoured
portion that curves inwardly towards the cavity of the cushion
along a radius to terminate at an inner edge of the membrane 32.
This arrangement more closely follows the contour or curvature of
the patient's nasal bridge region. In the illustrated embodiment,
the membrane 32 is angled with respect to a face contacting plane
of the cushion, e.g., in the range of 30-50.degree.. In contrast,
the corresponding angle of the UltraMirage.RTM. cushion 700 is
about 6.degree.. This arrangement provides more comfort and a
better fit for the patient.
Flat Portion in Nasal Bridge Region
[0102] As best shown in FIG. 38, the nasal bridge region 16 has a
substantially flat portion 50, e.g., on the apex of the membrane
curvature, in elevation view that may deform to provide a more
comfortable fit for a wide range of patients, e.g., from flatter
nasal bridges to sharper nasal bridges.
[0103] Specifically, one aspect of the invention is to provide a
membrane 32 in the nasal bridge region 16 that will accommodate
"flat faces", e.g., those patient's with a low nasal bridge. In
order to achieve this, the cushion 10 has an upper point A which is
higher than or level with points B (see FIG. 38). This height in
the nasal bridge region 16 is combined with a rolled edge that
keeps the surface area of the membrane 36 substantially flat
against the patient's nasal bridge. Keeping the surface area of the
membrane 36 substantially flat against the patient's nasal bridge
prevents leaks at the edge of the membrane.
[0104] The rolled edge also allows movement to accommodate higher
nasal bridges. This arrangement is achieved without "stretching"
the membrane which can lead to discomfort and patient sores. For
example, the displacement of the cushion 10 at the nasal bridge
region 16 may be greater than about 40 mm, e.g., 41 mm. In
contrast, the UltraMirage.RTM. cushion 700 provides displacement of
about 20 mm in the nasal bridge region. At these displacements, the
membrane becomes quite taut, i.e., the point on the force vs.
displacement graph where the force begins to rise sharply for a
small displacement (see FIG. 38B).
[0105] The displacement values of the cushion in the nasal bridge
region for some prior art cushions are as follows:
[0106] ResMed.TM. Activa.RTM. Nasal Cushion--16 mm
[0107] Respironics Comfort Full Face Cushion--26 mm
[0108] ResMed Bubble Nasal Mask Cushion--43 mm
[0109] Healthdyne Soft Series Nasal Mask Cushion--17 mm
[0110] The above displacement values are by no means an accurate
representation of what nose depth the cushion will cover. Rather,
these displacement values are only an indication of the flexibility
and/or range of the membrane. Thus, the cushion 10 provides an
arrangement that is much more flexible and/or rangy than the
UltraMirage.RTM. cushion 700, for example.
[0111] The force vs. displacement graph of membrane 32 in the nasal
bridge region 16 has a large displacement for relatively low
forces. For example, as shown in FIG. 38B, the displacement
provided by the cushion 10 in the nasal bridge region 16 is larger
than that provided by the UltraMirage.RTM. cushion 700. This allows
the cushion 10 to accommodate relatively deep nasal bridges in use.
Also, the molded (undeformed) cushion state of the UltraMirage.RTM.
cushion 700 (i.e., no force applied) does not comfortably
accommodate a relatively flat or shallow nasal bridge. In an
embodiment, the membrane of the cushion 700 blows out to meet
patient's faces with shallow nasal bridges. Thus, the cushion 10
also accommodates a wider range of nasal bridge shapes than the
UltraMirage.RTM. cushion 700.
[0112] Further, as shown in FIG. 36, the profile of the membrane is
more sharply peaked as compared to a flat profile or a saddle shape
(e.g., compare with UltraMirage.RTM. cushion 700 in FIG. 52). Also,
as shown in FIG. 35, flat portion in the nasal bridge region 16
extends along a relatively flat plane P1, and this plane P1 is
angled at an angle A with respect to the plane P2 that defines the
frame connection.
[0113] Thus, the shape (e.g., peak), the rolled edge, and the
height, in the nasal bridge region 16 provide large displacement at
relatively low forces. This arrangement accommodates a wider range
of patients, e.g., from those with a low nasal bridge to those with
a high nasal bridge, while maintaining a seal against the patient's
face with little force on the membrane.
[0114] It is noted that the cushion height may vary around the
cushion perimeter to vary flexibility or cushion displacement in
different regions of the cushion. A reference dimension 940 for
measurement of the cushion height (which may also be referred to as
the membrane height)--i.e. the height between the apex of the
membrane to where it meets the underlying cushion--is shown in FIG.
94C. A reference dimension 950 for measurement of the cushion
height of the prior art cushion is shown in FIG. 95C.
Aperture in Membrane
[0115] As shown in FIGS. 39-40B, the inner edge of the membrane 32
defines the aperture 22 that receives the patient's nose and mouth.
As illustrated, the aperture 22 has a generally triangular shape.
Also, the apex of the aperture 22 has a rounded notch 42, e.g.,
keyhole. The notch 42 improves the seal with nasal bridge regions
of various sizes and shapes, particularly patients with sharp
noses. The notch 42 has a radius of curvature in the range of
1.5-6.0 mm, preferably about 3.0 mm. This rounded keyhole shape has
a length, e.g., the keyhole shape extends outwards from an interior
portion of the cushion, of at least 3.0 mm, as shown in FIG.
40A.
Rolling Action of Nasal Bridge Region of Cushion in Use
[0116] FIGS. 41-45 include hand-marked lines applied to the outer
surface of the nasal bridge region 16 of the cushion 10 to
illustrate the rolling action of the nasal bridge region 16 of the
membrane 32 upon engagement with the patient's nose. As described
above, the membrane 32 in the nasal bridge region 16 includes
sloping sides 36 that meet to form an elongated crest 38 as shown
in FIG. 41. As the patient's nasal bridge (simulated using a small
rod) is engaged with the nasal bridge region 16 of the membrane 32
(see FIG. 42), the membrane 32 creates a steeply inverted section
44 wherein the sloping sides 36 invert their position as the
membrane 32 moves between the underlying cushions 30 provided in
the side of nose regions 17. As the membrane 32 comes more into
contact with the patient's nasal bridge, the leading edge 46 of the
inverted section "rolls" towards the top of the cushion 10 as the
membrane 32 conforms to the patient's face as shown in FIG. 43.
This structure is advantageous since it allows the cushion 10 to
accommodate patients having a wide range of nasal profiles,
including those with relatively low and relatively high root depth
at the nose. FIGS. 44 and 45 show the nasal bridge region 16 of the
membrane 32 in its completely inverted position. The creation of
the steeply inverted section 44 upon engagement with the patient's
nose provides a better seal and reduces the risk of creasing and/or
folding and associated discomfort and leaks. That is, this
configuration encourages rolling instead of creasing which can be
detrimental to patient comfort and seal.
Alternative Embodiments
[0117] FIGS. 54-71 illustrate another embodiment of a cushion 510.
In each of the figures, portions of the cushion 510 that are
substantially similar to the cushion 10 are indicated with similar
reference numerals.
[0118] FIG. 64 illustrates the base wall 528, underlying cushion
530, and membrane 532 of the cushion 510 (in solid lines) in
relation to the base wall 728, underlying cushion 730, and membrane
732 of the UltraMirage.RTM. Full Face cushion 700 (in dashed
lines). As illustrated, the cushion 510 has a different
cross-sectional profile than the UltraMirage.RTM. Full Face cushion
700.
[0119] For example, the membrane 532 is connected to the underlying
cushion 530 at a position that is further inwardly and upwardly
with respect to the membrane connection of the UltraMirage.RTM.
cushion 700. This arrangement substantially removes the vertically
extending groove 731 provided in the UltraMirage.RTM. cushion 700.
Also, this arrangement narrows the width of the membrane 532, e.g.,
in the range of 0-5, preferably about 2.5 mm, with respect to the
corresponding portion of the UltraMirage.RTM. cushion 700. As a
result of this and the inward movement of the non-face contacting
portion 512, this narrows the total width of the cushion 510 by
about 5 mm, e.g., about 2.5 mm per base, which provides a less
obtrusive cushion and saves material. Also, the narrower membrane
532 provides less free length for the cushion 510 to bulge
outwardly in use, thus helping to minimize or eliminate leakage.
Further, the base wall 528 and the frame connection 529 are
internally offset with respect to the most external cushion point,
e.g., external surface of underlying cushion. FIG. 64 also shows
the longer length a to b in the cushion 510 when compared to the
UltraMirage.RTM. cushion 700.
[0120] FIG. 65 illustrates further structural details and
dimensions in one embodiment of the base wall 528, underlying
cushion 530, and membrane 532 of the cushion 510. For example, the
depth of the space 534 is in the range of 0-4.0 mm, preferably
about 3.0 mm.
[0121] FIG. 68 illustrates the elongated ridge 535 in the nasal
bridge region 516. Each of the sloping sides 536 is angled from the
crest centerline in the range of 30-60.degree., preferably about
47.degree.. The crest 538 has a radius of curvature in the range of
1.0-5.0 mm, preferably about 2.5 mm. As shown in FIG. 69, the
forward end 540 of the elongated ridge 535 has a radius of
curvature in the range of 1.5-7.0 mm, preferably about 4.0 mm.
[0122] FIGS. 70 and 71 illustrate the flat portion 550 in the nasal
bridge region 516 of the cushion 510. Also, as shown in FIG. 71,
the membrane 532 in the nasal bridge region 516 has a first portion
with a radius of curvature in the range of 50-80 mm, preferably
about 65 mm, and a second portion with a radius of curvature in the
range of 5.5-9.5 mm, preferably about 7.5 mm. In the illustrated
embodiment, the membrane 532 is angled with respect to a face
contacting plane of the cushion in the range of 30-50.degree.,
preferably about 40.degree..
[0123] FIGS. 72-76 illustrate another embodiment of a cushion 610.
As best shown in FIG. 76, the cushion includes at least a base wall
628 and a membrane 632. As illustrated, the length of the membrane
632 (e.g., membrane cross-sectional length) in a nasal bridge
region may change. For example, the membrane length may be selected
to have a shorter length L.sub.1 or a longer length L.sub.2 in the
nasal bridge region.
[0124] As shown in FIGS. 74 and 75, the membrane length controls
how far on the patient's nose the displaced cushion membrane will
sit when fitted onto the patient's face (shown by the dotted line
on the patient's facial profile). This arrangement prevents the
potential (e.g., particularly for patients with a shallow nasal
bridge depth) for any excess cushion membrane to sit too far down
on the patient's nose, which may lead to facial discomfort and skin
markings on the patient's nose.
[0125] FIGS. 77-83 illustrate another embodiment of a cushion 810.
The cushion 810 includes a base wall 828, an underlying support
cushion 830, and a membrane 832. As described above, the underlying
cushion 830 is preferably provided on lateral sides of the cushion
810 only.
[0126] The base wall 828 may be internally offset with respect to
the most external cushion point, e.g., external surface of membrane
or underlying cushion. This arrangement provides a spring
characteristic which may be varied around the cushion perimeter to
vary the cushion flexibility (lateral and/or vertical) around the
cushion perimeter, e.g., the cushion stiffness can be varied at
each cushion region to suit the sealing requirements in each region
which may vary due to the underlying facial structure of the
patient. That is, the level if bias (e.g., from "hard" to "soft")
along the sides of the cushion may be changed.
[0127] For example, FIGS. 77-83 illustrate cross-sections through
three different regions R1, R2, R3 in the cushion 810. As shown in
FIG. 81, the base wall 828, the underlying cushion 830, and the
membrane 832 cooperate to define a relatively straight external
surface 880. This provides a minimal spring component in the region
R1, e.g., hard or stiff characteristics.
[0128] As shown in FIG. 82, the base wall 828, the underlying
cushion 830, and the membrane 832 cooperate to define an external
surface 882 that transitions from a relatively straight
configuration to a curved configuration. This provides a relatively
small offset for a more flexible spring component than the region
R1.
[0129] As shown in FIG. 83, the base wall 828, the underlying
cushion 830, and the membrane 832 cooperate to define an external
surface 884 that curves outwards from the base wall 828. This
provides a relatively large offset for an optimal spring component
in the region R3, e.g., soft or flexible characteristics.
[0130] Thus, the cushion 810 may be designed to provide varying
flexibilities around its perimeter which allows the cushion 810 to
conform to a variety of facial shapes.
[0131] FIGS. 84-90 illustrate another embodiment of a cushion 910.
The cushion 910 includes a base wall 928, an underlying support
cushion 930, and a membrane 932. As illustrated, the underlying
cushion 930 is preferably provided on lateral sides of the cushion
910 only, e.g., no underlying cushion at nasal bridge and chin
regions (see FIG. 88).
[0132] As shown in FIG. 90, the base wall 928 includes a tapered
portion 990 when compared to FIG. 89, which tapers towards the
membrane 932. This arrangement may improve moldability.
[0133] FIG. 91 illustrates an alternative arrangement to the
cushion 10 of FIG. 34A (arrangement of FIG. 34A shown in dashed
lines). As illustrated, material has been removed from the side
wall 28 and the space or gap 34 has been reduced with respect to
the arrangement of FIG. 34A. This arrangement of FIG. 91 increases
displacement with respect to the previous displacement of FIG. 34A.
The increased displacement is achieved by the changed geometry in
the side wall 28. It is noted that the gap 34 may be variable or
constant around the cushion perimeter.
[0134] FIG. 92 illustrates an alternative arrangement to the
cushion 10 of FIG. 34A (arrangement of FIG. 34A shown in dashed
lines). As illustrated, some material has been removed from the
side wall 28 and the space or gap 34 has been reduced with respect
to the arrangement of FIG. 34A. This arrangement of FIG. 92
increases displacement with respect to the previous displacement of
FIG. 34A. The increased displacement is achieved by the changed
geometry in the side wall 28. This arrangement may require the
cross-section of the base wall 28 to be thickened to add stiffness
around the cushion perimeter or locally. Stiffening may be achieved
by local ribs where required.
[0135] FIG. 93 illustrates an alternative arrangement to the
cushion 10 shown in FIG. 15. As illustrated, the keyhole-shaped
cutout (for receiving the patient's nasal bridge region) may be
larger as the mask size reduces. For example, the cutout is larger
for an extra small size mask than a large size mask.
[0136] It is noted that the cross-section design of the cushion at
specific areas of the patient's face (e.g., FIGS. 23-29) may be in
the specific area or any area around the cushion perimeter. That
is, the cross-section design should not be limited to the specified
area. Also, the cross-section shown in FIGS. 91 and 92 may be
employed at any point around the cushion perimeter.
[0137] 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.
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. 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,
barriatric 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.
* * * * *