U.S. patent application number 15/651957 was filed with the patent office on 2018-01-04 for breathing assistance apparatus.
The applicant listed for this patent is Fisher & Paykel Healthcare Limited. Invention is credited to Fiona Elizabeth Cresswell, Lewis George Gradon, Mark Joseph Haycock, Daniel Mahon, Alastair Edwin McAuley, Christopher Earl Nightingale, Nicholas Charles Alan Smith.
Application Number | 20180001047 15/651957 |
Document ID | / |
Family ID | 27484393 |
Filed Date | 2018-01-04 |
United States Patent
Application |
20180001047 |
Kind Code |
A1 |
McAuley; Alastair Edwin ; et
al. |
January 4, 2018 |
BREATHING ASSISTANCE APPARATUS
Abstract
A CPAP system for supplying humidified gases to a user is
disclosed in which various interfaces are described for gas
delivery. A mask cushion including a deformable cushion and thin
sheath is described.
Inventors: |
McAuley; Alastair Edwin;
(Auckland, NZ) ; Nightingale; Christopher Earl;
(Auckland, NZ) ; Gradon; Lewis George; (Auckland,
NZ) ; Haycock; Mark Joseph; (Te Awamuto, NZ) ;
Smith; Nicholas Charles Alan; (Auckland, NZ) ; Mahon;
Daniel; (Auckland, NZ) ; Cresswell; Fiona
Elizabeth; (Auckland, NZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fisher & Paykel Healthcare Limited |
Auckland |
|
NZ |
|
|
Family ID: |
27484393 |
Appl. No.: |
15/651957 |
Filed: |
July 17, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14136930 |
Dec 20, 2013 |
9707368 |
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15651957 |
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|
12410863 |
Mar 25, 2009 |
8613279 |
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14136930 |
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11928779 |
Oct 30, 2007 |
8602029 |
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12410863 |
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10456661 |
Jun 6, 2003 |
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11928779 |
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10297951 |
Mar 25, 2003 |
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PCT/NZ01/00110 |
Jun 14, 2001 |
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10456661 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 16/16 20130101;
A61M 16/0816 20130101; A61M 16/0616 20140204; A61M 16/0066
20130101; A61M 16/1095 20140204; A61M 16/0825 20140204; A61M
2016/0039 20130101; A61M 16/0488 20130101; A61M 16/0069 20140204;
A61M 16/06 20130101; A61M 16/0057 20130101; A61M 16/109 20140204;
A61M 16/08 20130101; A61M 16/065 20140204; A61M 16/1065 20140204;
A61M 2205/42 20130101; A61M 16/0493 20140204; A61M 16/0495
20140204; A61M 16/0666 20130101; A61M 16/0683 20130101; A61M
16/0638 20140204; A61M 16/1045 20130101; A61M 16/0622 20140204 |
International
Class: |
A61M 16/08 20060101
A61M016/08; A61M 16/10 20060101 A61M016/10; A61M 16/00 20060101
A61M016/00; A61M 16/04 20060101 A61M016/04; A61M 16/06 20060101
A61M016/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 14, 2000 |
NZ |
505154 |
Jun 14, 2000 |
NZ |
505156 |
Dec 20, 2000 |
NZ |
509039 |
Mar 12, 2001 |
NZ |
510520 |
Claims
1. (canceled)
2. An elbow connector adapted to connect a patient interface with a
supply of gases, the elbow connector comprising: a hollow body
having an inlet and an outlet, the hollow body defining an air flow
channel, the inlet configured to be in fluid communication with the
supply of gases in use and the outlet configured to be in fluid
communication with the patient interface in use; a wall of the
hollow body defining the air flow channel, the wall being
cylindrical, the cylindrical wall having a proximal portion closest
to a user and a distal portion furthest from the user, the
cylindrical wall also having a curved portion that bends in a first
direction such that a length of the distal portion is longer than a
length of the proximal portion, the distal portion comprising a
flexible thin portion along the curved portion of the cylindrical
wall such that the flexible thin portion is curved in two
dimensions; and the thin portion comprising a plurality of
apertures configured to externally vent gases exhaled by the
user.
3. The elbow connector of claim 2, wherein the elbow connector has
at least a portion formed from polycarbonate.
4. The elbow connector of claim 2, wherein the elbow connector has
at least a portion formed from Hytrel plastic.
5. The elbow connector of claim 2, wherein the apertures have
rounded peripheries.
6. The elbow connector of claim 2, wherein the plurality of
apertures are configured to reduce noise caused by venting of the
gases exhaled by the user.
7. The elbow connector of claim 2, wherein the plurality of
apertures are arranged in a circle.
8. The elbow connector of claim 7, wherein the flexible thin
portion is circular.
9. An elbow connector adapted to connect a patient interface with a
supply of gases, the elbow connector comprising: a hollow body
having an inlet and an outlet, the hollow body defining an air flow
channel, the inlet configured to be in fluid communication with the
supply of gases in use and the outlet configured to be in fluid
communication with the patient interface in use, the hollow body
comprising a thin portion positioned along a curved portion of the
elbow connector, the thin portion being thinner in cross section
than an adjacent portion of the hollow body, the thin portion
comprising a plurality of apertures configured to externally vent
gases exhaled by the user.
10. The elbow connector of claim 9, wherein the material that forms
the elbow connector has an increasing flexibility with a decreasing
thickness.
11. The elbow connector of claim 10, wherein the elbow connector
comprises at least a portion formed from polycarbonate.
12. The elbow connector of claim 11, wherein the thin portion is
more flexible than the remainder of the hollow body.
13. The elbow connector of claim 10, wherein the elbow connector
comprises at least a portion formed from Hytrel plastic.
14. The elbow connector of claim 13, wherein the thin portion is
more flexible than the remainder of the hollow body.
15. The elbow connector of claim 9, wherein the thin portion is
located in a distal portion of the hollow body positioned away from
the user in use.
16. The elbow connector of claim 15, wherein the plurality of
apertures are arranged in a circle.
17. The elbow connector of claim 16, wherein the thin portion is
circular.
18. The elbow connector of claim 17, wherein the apertures have
rounded peripheries.
Description
INCORPORATION BY REFERENCE
[0001] This application is a Divisional of U.S. patent application
Ser. No. 14/136,930, filed Dec. 20, 2013, which is a Continuation
of U.S. patent application Ser. No. 12/410,863, filed Mar. 25,
2009, now U.S. Pat. No. 8,613,279, which is a Continuation-In-Part
of U.S. patent application Ser. No. 11/928,779 filed Oct. 30, 2007,
now U.S. Pat. No. 8,602,029, which is a Continuation of U.S. patent
application Ser. No. 10/456,661 filed on Jun. 6, 2003, now
abandoned, which is a Divisional of U.S. patent application Ser.
No. 10/297,951, which received a 371 filing date of Mar. 25, 2003,
now abandoned, which is a 371 filing of PCT/NZ01/0011.0 filed on
Jun. 14, 2001. Each of the aforementioned patents/applications is
hereby incorporated by reference.
FIELD OF INVENTION
[0002] This invention relates to patient interfaces particularly
though not solely for use in delivering CPAP therapy to patients
suffering from obstructive sleep apnea (OSA).
BACKGROUND OF THE INVENTION
[0003] In the art of respiration devices, there are well known
variety of respiratory masks which cover the nose and/or mouth of a
human user in order to provide a continuous seal around the nasal
and/or oral areas of the face such that gas may be provided at
positive pressure within the mask for consumption by the user. The
uses for such masks range from high altitude breathing (i.e.,
aviation applications) to mining and fire fighting applications, to
various medical diagnostic and therapeutic applications.
[0004] One requisite of such respiratory masks has been that they
provide an effective seal against the user's face to prevent
leakage of the gas being supplied. Commonly, in prior mask
configurations, a good mask-to-face seal has been attained in many
instances only with considerable discomfort for the user. This
problem is most crucial in those applications, especially medical
applications, which require the user to wear such a mask
continuously for hours or perhaps even days. In such situations,
the user will not tolerate the mask for long durations and optimum
therapeutic or diagnostic objectives thus will not be achieved, or
will be achieved with great difficulty and considerable user
discomfort.
[0005] U.S. Pat. No. 5,243,971 and U.S. Pat. No. 6,112,746 are
examples of prior art attempts to improve the mask system U.S. Pat.
No. 5,570,689 and PCT publication No. WO 00/78384 are examples of
attempts to improve the forehead rest.
[0006] Where such masks are used in respiratory therapy, in
particular treatment of obstructive sleep apnea (OSA) using
continuance positive airway pressure (CPAP) therapy, there is
generally provided in the art a vent for washout of the bias flow
or expired gases to the atmosphere. Such a vent may be provided for
example, as part of the mask, or in the case of some respirators
where a further conduit carries the expiratory gases, at the
respirator. A further requisite of such masks is the washout of gas
from the mask to ensure that carbon dioxide build up does not occur
over the range of flow rates. In the typical flow rates in CPAP
treatment, usually between 4 cm H.sub.2O to 20 cm H.sub.2O, prior
art attempts at such vents have resulted in excessive noise causing
irritation to the user and any bed partners.
[0007] Various approaches have been developed in the prior art to
attempt to reduce the noise when CPAP therapy is provided. For
example, in PCT Patent Application number WO98/34665 it has been
proposed that the vent include a resilient plug with rounded edge
apertures to reproduce noise. However, this is not entirely
effective in eliminating the extra noise created by a vent at the
mask.
[0008] In common with all attempts to improve the fit, sealing and
user comfort is the need to avoid a concentrated flow of air at any
portion of the respiratory tracts. In particular with oral masks or
mouthpieces it is a disadvantage of prior art devices that the oral
cavity may become overly dehydrated by use of the device, causing
irritation and possible later complications.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to attempt to
provide a patient interface which goes some way to overcoming the
abovementioned disadvantages in the prior art or which will at
least provide the industry with a useful choice.
[0010] In a first aspect the present invention consists in a
patient interface for delivering a supply of gases to a user
comprising:
[0011] a hollow body including a gases inlet and a gases delivery
aperture, said gases delivery aperture having a periphery, said
gases inlet in use in fluid communication with a supply of
gases,
[0012] a resilient inner cushion,
[0013] a flexible sealing sheath adapted to engage with said
periphery and at least partially covering said resilient inner
cushion.
[0014] Preferably said resilient inner cushion is adapted to deform
substantially independently of said flexible sealing sheath.
[0015] Preferably said resilient inner cushion is a polyurethane
cushion.
[0016] Preferably said flexible sealing sheath substantially
covers, and is substantially thinner than, said resilient inner
cushion.
[0017] Preferably said hollow body has a flange at least partially
around the interior of said hollow body, said flange and said
interior forming a cavity adapted to house in use a part of said
resilient inner cushion.
[0018] Preferably said flexible sealing sheath holds the resilient
inner cushion in place within said patient interface.
[0019] Preferably said flexible sealing sheath is scented.
[0020] Preferably said flexible sealing sheath is scented with a
vanilla scent.
[0021] In a second aspect the present invention consists in a
patient interface capable of supplying gases to a user
comprising:
[0022] a resilient pad,
[0023] a flexible sealing sheath, adapted to engage about said
resilient sealing pad, said flexible sealing sheath having a
periphery and a channel in said periphery,
[0024] a hollow body including a gases inlet and a gases delivery
aperture, said hollow body having a lip at said gases delivery
aperture capable of fitting into said channel of said flexible
sealing sheath thereby enabling said flexible sealing sheath to be
releasably secured to said hollow body.
[0025] Preferably said flexible sealing sheath holds said resilient
inner cushion in place within said patient interface.
[0026] Preferably said flexible sealing sheath is scented.
[0027] Preferably said flexible sealing sheath is scented with a
vanilla scent.
[0028] To those skilled in the art to which the invention relates,
many changes in construction and widely differing embodiments and
applications of the invention will suggest themselves without
departing from the scope of the invention as defined in the
appended claims. The disclosures and the descriptions herein are
purely illustrative and are not intended to be in any sense
limiting.
[0029] In this specification where reference has been made to
patent specifications, other external documents, or other sources
of information, this is generally for the purpose of providing a
context for discussing the features of the invention. Unless
specifically stated otherwise, reference to such external documents
is not to be construed as an admission that such documents, or such
sources of information, in any jurisdiction, are prior art, or form
part of the common general knowledge in the art.
[0030] The invention consists in the foregoing and also envisages
constructions of which the following gives examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Preferred forms of the present invention will now be
described with reference to the accompanying drawings.
[0032] FIG. 1 is a block diagram of a humidified continuous
positive airway pressure (system) as might be used in conjunction
with the present invention,
[0033] FIG. 2 is an illustration of the nasal mask in use according
to the preferred embodiment of the present invention,
[0034] FIG. 3 is a side elevational view of the mouthpiece as being
used by a patient,
[0035] FIG. 4 is a perspective view from above of the
mouthpiece,
[0036] FIG. 5 is a perspective view from one side and from an
inward direction of the mouthpiece of FIG. 4,
[0037] FIG. 6 is a cross-section of the mouthpiece of FIG. 4,
[0038] FIG. 7 is a cross sectional view of the mouthpiece of FIG. 4
and a user with the mouthpiece in place to demonstrate the location
and positioning thereof in relation to the main features of the
user's anatomy,
[0039] FIG. 8 is a perspective view of the mouthpiece with the
outer flap in place,
[0040] FIG. 9 is a perspective view of the outer flap bent
back,
[0041] FIG. 10 is a cutaway view of the mouthpiece with the outer
flap in use,
[0042] FIG. 11 is a perspective view of the outer flap including
the ventilation apertures and moisture barrier,
[0043] FIG. 12 shows the outlet vent sleeve installed on the
elbow.
[0044] FIG. 13 shows the outlet vent sleeve in isolation,
[0045] FIG. 14 shows the elbow in isolation,
[0046] FIG. 15 shows the one piece elbow outlet vent interior,
[0047] FIG. 16 shows the one piece elbow outlet vent exterior,
[0048] FIG. 17 shows a cross section of the mouthpiece with a
dispersing filter,
[0049] FIG. 18 shows a perspective view of the mask with
cushion,
[0050] FIG. 19 is a cutaway view of the mask showing the
cushion,
[0051] FIG. 20 is a cutaway view of the periphery of the outer
membrane,
[0052] FIG. 21 is a cutaway view of the periphery of the mask body
portion,
[0053] FIG. 22 shows a make with the forehead rest on a user,
and
[0054] FIG. 23 shows the forehead rest in isolation.
DETAILED DESCRIPTION
[0055] The present invention provides improvements in the delivery
of CPAP therapy. In particular a patient interface is described
which is quieter for the user to wear and reduces the side leakage
as compared with the prior art. It will be appreciated that the
patient interface as described in the preferred embodiment of the
present invention can be used in respiratory care generally or with
a ventilator but will now be described below with reference to use
in a humidified CPAP system. It will also be appreciated that the
present invention can be applied to any form of patient interface
including, but not limited to, nasal masks, oral masks and
mouthpieces.
[0056] With reference to FIG. 1 a humidified Continuous Positive
Airway Pressure (CPAP) system is shown in which a patient 1 is
receiving humidified and pressurised gases through a patient
interface 2 connected to a humidified gases transportation pathway
or inspiratory conduit 3. It should be understood that delivery
systems could also be VPAP (Variable Positive Airway Pressure) and
BiPAP (Bi-level Positive Airway Pressure) or numerous other forms
of respiratory therapy. Inspiratory conduit 3 is connected to the
outlet 4 of a humidification chamber 5 which contains a volume of
water 6. Inspiratory conduit 3 may contain heater wires (not shown)
which heat the walls of the conduit to reduce condensation of
humidified gases within the conduit. Humidification chamber 5 is
preferably formed from a plastics material and may have a highly
heat conductive base (for example an aluminium base) which is in
direct contact with a heater plate 7 of humidifier 8. Humidifier 8
is provided with an electronic controller 9 which may comprise a
microprocessor based controller executing computer software
commands stored in associated memory.
[0057] Controller 9 receives input from sources such as dial 10
through which a user of the device may, for example, set a
predetermined required value (preset value) of humidity or
temperature of the gases supplied to patient 1. The controller may
also receive input from other sources, for example temperature
and/or flow velocity sensors 11 and 12 through connector 13 and
heater plate temperature sensor 14. In response to the user set
humidity or temperature value input via dial 10 and the other
inputs, controller 9 determines when (or to what level) to energise
heater plate 7 to heat the water 6 within humidification chamber 5.
As the volume of water 6 within humidification chamber 5 is heated,
water vapour begins to fill the volume of the chamber above the
water's surface and is passed out of the humidification chamber 5
outlet 4 with the flow of gases (for example air) provided from
blower 15 which enters the chamber through inlet 16. Exhaled gases
from the patient's mouth are passed directly to ambient
surroundings in FIG. 1.
[0058] Blower 15 is provided with variable speed fan 21 which draws
air or other gases through blower inlet 17. The speed of variable
speed fan 21 is controlled by electronic controller 18 (or
alternatively the function of controller 18 could carried out by
controller 9) in response to inputs from controller 9 and a user
set predetermined required value (preset value) of pressure or fan
speed via dial 19.
Nasal Mask
[0059] According to a first embodiment of the present invention the
patient interface is shown in FIG. 2 as a nasal mask. The mask
includes a hollow body 102 with an inlet 103 connected to the
inspiratory conduit 3. The mask 2 is positioned around the nose of
the user 1 with the headgear 108 secured around the back of the
head of the patient 1. The restraining force from the headgear 108
on the hollow body 102 and the forehead rest 106 ensures enough
compressive force on the mask cushion 104, to provide an effective
seal against the patient's face.
[0060] The hollow body 102 is constructed of a relatively
inflexible material for example, polycarbonate plastic. Such a
material would provide the requisite rigidity as well as being
transparent and a relatively good insulator. The expiratory gases
can be expelled through a valve (not shown) in the mask, a further
expiratory conduit (not shown), or any other such method as is
known in the art.
Mask Cushion
[0061] Referring now to FIGS. 18 and 19 in particular, the mask
cushion 1104 is provided around the periphery of the nasal mask
1102 to provide an effective seal onto the face of the user to
prevent leakage. The mask cushion 1104 is shaped to approximately
follow the contours of a patient's face. The mask cushion 1104 will
deform when pressure is applied by the headgear (not shown) to
adapt to the individual contours of any particular user. In
particular, there is an indented section 1150 intended to fit over
the bridge of the user's nose as well as a less indented section
1152 to seal around the section beneath the nose and above the
upper lip.
[0062] In FIG. 19 we see that the mask cushion 1104 is composed of
an inner foam cushion 1110 covered by an outer sealing sheath 1112.
The inner cushion 1110 is constructed of a resilient material for
example polyurethane foam, and can deform independently of outer
sealing sheath 1112 in order to enable it to distribute pressure
evenly along the seal around the user's face formed by sealing
sheath 1112. Inner cushion 1110 can also act as a secondary seal.
The inner cushion 1110 is located around the outer periphery 1114
of the open face 1116 of the hollow body 1102. The open face 1116
acts as a gases delivery aperture to deliver gases to a user.
Similarly the outer sheath 1112 may be commonly attached at its
base 1113 to the periphery 1114 and loosely covers over the top of
the inner cushion 1110.
[0063] In the preferred embodiment, shown in FIGS. 19 to 21 the
bottom of the inner cushion 1110 fits into a generally triangular
cavity 1154 in the hollow body 1102. The cavity 1154 is formed from
a flange 1156 running mid-way around the interior of the hollow
body.
[0064] The outer sheath 1112 fits in place over the cushion 1110,
holding it in place. The sheath 1112 is secured by a snap-fit to
the periphery 1114 of the hollow body. In FIGS. 20-21 the periphery
1114 is shown including an outer bead 1158. The sheath 1112
includes a matching bead 1159, whereby once stretched around the
periphery, the two beads engage to hold the sheath in place.
Forehead Rest
[0065] In the preferred embodiment of the present invention the
nasal mask 2102 includes a hinged forehead rest 2106 (seen in FIGS.
22 and 23). The attachment of the forehead rest 2106 to the nasal
mask 2102 effectively allows the forehead rest 2106 to move freely
in proximity to the user but with no lateral movement.
[0066] In one form shown in FIG. 23, pins 2130 are provided mounted
on a base 2132 attached to the nasal mask 2102. These pins 2130 are
co-axial within cylinders 2131 mounted on a bridge member 2136.
[0067] At the top end 2142 (around the user's forehead) of the
bridge member 2136 harnessing slots 2138 are provided which allow
straps from the headgear to be inserted to secure the mask to the
headgear. For the users comfort one or more resilient cushions 2140
are provided underneath the top end 2142 of the bridge member 2136,
which rest on the forehead of the user. The cushion 2140 might be
constructed of silicon or any foam materials as is known in the art
for providing cushioning.
[0068] For example the forehead rest 2106 described previously may
include a weakened section at its base 2132 which allows the
joining member 2136 to pivot from the nasal mask 2102. The bridge
member extends up to the forehead of the user. In a further
alternative the mask may include a vertical upwardly extending
inlet. In this case the member 2136 is hinged at its base 2132 to
either side of the inlet passage. Again the member would then
extend to the forehead. Alternatively any well-known form of hinge
can be used to provide the pivoting action.
Mouthpiece
[0069] Now with reference to a further inlet embodiment of the
present invention the patient interface 2 is shown in FIGS. 3 to 10
as a mouthpiece. In this embodiment, the mouthpiece 50 includes a
vestibular shield 49 being a generally flat and generally
rectangularly-shaped member in front elevation having a curved
profile that reflects the curvature of a user's jaw and in turn the
curvature of the labial vestibule region. A gases passageway
extends through the vestibular shield from an inlet 51 to an outlet
52 in much the same way as with the earlier embodiments. In the
preferred embodiment the inlet 51 is provided by a flattened
oval-shaped connector 53. The outlet 52 has an even more laterally
extended flattened oval shape 54. The major differences between the
mouthpiece 50 and the embodiments described above are provided on
the inner face of the vestibular shield. Most prominently, the
mouthpiece 50 includes a tongue depressor 55 extending from the
inner face of the vestibular shield 49. The operation of the tongue
depressor will be described further on with reference to FIG. 5.
The tongue depressor includes a vertical stiffening flange 56
centrally located on its upper surface and extending from the gases
outlet 52. In use gases flow easily around the stiffening flange 56
effectively bifurcating the gases outlet 52. The tongue depressor
55 further includes a pair of vertically extending spacers 57 which
in use may abut against the roof of the wearer's mouth and ensure
that the tongue cannot completely block the air passageway. In the
mouthpiece 50 the sealing effect of the vestibular shield 49
against the lips of the user is enhanced by providing teeth
abutments of significantly increased thickness than the raised area
of the earlier embodiments. In particular, an upper teeth abutment
58 and a lower teeth abutment 59 are provided, with the lower teeth
abutment 59 protruding further from the inner face of the
vestibular shield 49 than the upper teeth abutment 58. This
difference serves to match the typical over-bite of most users. The
abutments 58 and 59 are not required to be wider than the gases
outlet 52.
[0070] A notch 60 is provided centrally in the upper edge of the
vestibular shield 49 to accommodate the upper frenal attachment. A
slight bead 61 is provided around the edge of the vestibular shield
49 for user comfort, with the vestibular shield 49 otherwise being
very thin for additional suppleness.
[0071] Referring particularly to FIG. 6, in its preferred form the
mouthpiece 50 is preferably formed by over moulding a soft and
supple material part 70 over a stiffer material part 67. These can
generally be termed the shield part and the passageway-forming
insert. The passageway-forming insert preferably includes a pair of
upper and lower vertical flanges 63 and 64 to fully engage within
the supple material. The passageway forming insert 67 includes the
vertically extending stiffening flange 56 of the tongue depressor
55, together with a curved planar portion 71 forming the backbone
of the tongue depressor 55. The vertically extending spacers 57 are
of the soft and supple material and are part of the over-moulding
70, as are the upper and lower teeth abutments 58 and 59.
[0072] Referring now to FIG. 7, use of the mouthpiece according to
FIGS. 4 to 6 is depicted. With the present mouthpiece 50, the upper
and lower lips 85, 86 are further distended by the abutment action
of the abutments 75, 76 against the upper and lower teeth 87, 83
respectively, thus forming a seal of greater pressure between the
lips 85, 86 and the upper and lower portions 74, 73, respectively,
of the vestibular shield 49. A lower face 77 of the tongue
depressor 55 impinges if necessary on the upper surface 72 of the
tongue 90 and retains the tongue in the lower portion of the mouth.
This ensures a clear gases outlet 52 from the gases passageway
through the vestibular shield. The vertically extending spacers 57,
if forced by pressure from the tongue, will engage against the roof
78 of the user's mouth and maintain a clear air passageway. This
stops the sleeping patient unconsciously blocking the oral
passageway and reverting to nasal breathing.
[0073] Referring now to FIGS. 8 and 9 of the present invention a
mouthpiece is illustrated including an extra-oral sealing flap 110.
The flap 110 in its natural bias is tapered, the wide open end of
which is shaped to conform to the facial contours around the
outside of the mouth of a user. The narrow end joins to a
cylindrical section, which is designed to slide over the inlet port
114 of the mouthpiece 112. While this is one method of attachment
the flap 100 might also be constructed as an integral part of the
mouthpiece 112. The flap 110 needs to be constructed of flexible
material, therefore materials such as silicone rubber can be
employed to fashion the flap.
[0074] The outer flap 110 is seen in FIG. 9, in a bent back
position. It will be appreciated that when the mouthpiece 112 is
being inserted into the mouth of a user, the outer flap 110 is
intended to be in this bent back position to aid insertion. Prior
to insertion, the outer flap is bent back by simply pressing on its
outer periphery 116, until it snaps into the bent back position, in
which it will stay unaided.
[0075] In FIG. 10 we see the outer flap 110 in use with the
mouthpiece 112 in the mouth 117 of a user 119. Once correctly
positioned in the mouth 116, the outer flap 110 may be adjusted
into its operational position by pressing on its outer periphery
116 until it snaps back to press against the outside of the mouth
118. Due to the relative position of the vestibular shield 122 and
the outer flap 110, the outer flap 110 is unable to fully reach its
natural bias and thereby inflicts a compressive force on the
outside of the mouth 118.
[0076] It will be appreciated that as well as providing a
substantially airtight seal the addition of the outer flap provides
enough compressive force on the mouth to keep the mouthpiece and
conduit in place without the need for straps. This allows the
administering of CPAP therapy to be considerably less obtrusive
than traditional methods.
[0077] In a further additional improvement shown in FIG. 11, the
outer flap 300 is shown in perspective. Included are ventilation
apertures 302, 303 either side of the gases port 304, which are
surrounded by a ridge 306 acting as a moisture barrier. The
apertures 302,303 are provided such that any excess moisture
leaking from the mouth will migrate to the apertures where they may
evaporate. Small vents in the conduit may be used to direct small
amounts of pressurised gas at the apertures to aid evaporation. The
ridge 306 is included to ensure that no moisture migrates further
into the sealing region 308, as this would be detrimental to the
sealing properties of the flap.
Interface Connection
[0078] Attention is now directed to FIG. 3. It has been found that
an additional factor in the effectiveness of any patient interface
2 is the manner in which the interface is connected to the
breathing circuit 41. The weight of the breathing circuit 41, and
any attempted movement of one other of the breathing circuit 41 and
the interface 2 relative to the other, is one of the largest
influences tending to dislodge the interface 2. It must be noted
that the interface 2 must remain in positron and maintain a seal
during all sleep, when the user has no muscle tone.
[0079] The connection 40 as provided in the present invention
between the breathing circuit 41 and the interface 2 decouples the
interface 2 from the breathing circuit 41. As a result, the
connection 40 is effective in reducing the forces placed on the
interface 2 by the breathing circuit 41 when the user moves around
during sleep. In the preferred sleeping position, the breathing
circuit 41 is laid across the chest 43 of the user, and may be
scented to the user's bed clothes or sleeping garments. The
breathing circuit 41 is preferably laid on the chest of the user to
take the weight of the breathing circuit 41 off of the interface
2.
[0080] To connect between the gases outlet 42 which is vertical
when the user is lying on his or her back and the breathing circuit
41 which is generally horizontal, an L-shaped elbow 45 is
incorporated in the connection 40. The elbow 45 may be incorporated
in the interface 2. The elbow 45 is formed at a right angle and
provides a positive pressure on the interface 2. The elbow 45 may
include a swivel joint and may be disconnected from gases outlet
42. The connection 40 further includes an extremely flexible
connecting tube 46 provided between the elbow 45 and the breathing
circuit 41. The connecting tube 46 is preferably connected to the
breathing circuit 41 by a swivel joint 48 for reasons described
herein. The breathing circuit 41, while flexible, will necessarily
be stiff enough to maintain its integrity over comparatively long
lengths, while the connecting tube 46, being only a short length,
for example 10 centimeters, merely has to span between the user's
mouth and chest, and can thereby be made in a manner that would not
be suitable for long lengths. Furthermore, as a result of the short
length of the connecting tube 46, the connecting tube 46 does not
need to incorporate significant insulation or heating capability.
The connecting tube 46 may be formed from a thin plastic membrane
supported over a helical or double helical or corrugated supporting
ribs. In such a case, the support makes the connection tube 46
laterally flexible and resistant to torsion. The elbow swivel joint
45 allows for movement of the connection tube 46 relative to the
interface 2. The swivel joint 48 allows for movement of the
connection tube 46 relative to the breathing circuit 41. It is to
be understood that one or both of the swivel joints 45, 48 could be
eliminated, but the preferred embodiment includes swivel joint
48.
Outlet Vent
[0081] The present invention will now be described with reference
to the various different embodiments previously described. In order
to reduce the noise caused by expiratory gases being expelled from
the patient interface 2, the present invention is illustrated in
FIGS. 12 to 17 with the elbow connector (previously designated as
45) including an outlet vent. It would be appreciated by one
skilled in the art that the elbow connector as described herein
will be equally applicable to all proceeding embodiments and all
other forms of patient interface for delivering CPAP therapy.
[0082] Referring particularly now to FIGS. 12 to 14, the elbow
connector is illustrated including a flexible sleeve 400 which fits
overtop of the elbow connector. The sleeve 400 is preferably
constructed of silicon, but it will be appreciated by one skilled
in the art that a number of other flexible materials will be
equally applicable. The sleeve 400 includes locating indents 402
which once installed on the elbow connector match up with and lock
into locating notches 404 on the elbow connector. The location is
necessary so that the outlet aperture 406 in the elbow connector
always matches up with the outlet vents 408 in the outlet sleeve
400. This then prevents the undesirable situation where the sleeve
could slip and the outlet vents 408 not match up with the outlet
aperture 406 with resulting consequences to the patient.
[0083] Referring now to FIGS. 15 and 16, the present invention is
shown with a one-piece elbow. In this case the elbow is preferably
constructed of either "Hytrel" plastic or polycarbonate. In this
fashion the elbow connector is manufactured to have a thin portion
410 surrounding the outlet vents 412 in comparison to the remainder
of the elbow connector which is considerably thicker. The
properties of the material chosen for the elbow connector are such
that its flexibility is dependent on its thickness. Therefore in
the thin portion 410 the elbow connector is relatively flexible and
in the remainder is relatively rigid. Accordingly the outlet vents
412, which are also rounded on their periphery are formed in a
flexible portion, and therefore achieve the desirable low noise
properties when expiratory gases are vented there through.
Flow Diffuser
[0084] Referring now particularly to the use of mouthpieces, a
further improvement is shown in FIG. 17. It is documented that when
CPAP therapy is delivered to patients they often complain of drying
of the airways and resulting irritation and discomfort. In
particular when a concentrated airflow of under humidified gases
flows past the oral or nasal cavities, or the airway of the user
then drying and irritation may occur. Accordingly the present
invention as illustrated in FIG. 17 includes a mouthpiece with a
flow diffuser 500.
[0085] As described in the preceding embodiments, the mouthpiece
sits with a vestibular shield 502 between the gums 504 and the lips
506 of a user. An outer flap 508 provides compressor force on the
lips 506 to keep the mouthpiece in place in the user's month. Again
the mouthpiece includes a tongue depressor 514 extending into the
user's oral cavity.
[0086] In the preceding embodiments the delivered gases would flow
through passageway 512 in the mouthpiece, causing a relatively
concentrated flow of gases to flow through the oral cavity and down
the airway. With the flow diffuser 500 fitted overtop of the
passageway 512 the flow is defused over the much larger area of the
diffuser 500, and therefore both the speed and side effects are
reduced.
[0087] Alternatively the space between the passageway 512 and the
diffuser 500 could be filled with a Humidity Moisture Exchange
(HME) material. This would allow moisture through on the
inspiratory flow put prevent it passing out an expiration. This
would further prevent against the patient's passageways drying out.
Further, if the HME material was in the form of foam, then it might
also act as the diffuser 500. It will also be appreciated that the
HME material could be used in the space 516 all the way out to the
elbow connector (not shown) to maximise its effect.
[0088] It will be appreciated that by providing such a system the
present invention effectively minimises the noise generated by the
outward flow of expiratory gases from the mask. The present
invention requires little or no maintenance. The present invention
also provides a flow diffuser for use with the mouthpiece, which
reduces any side effects of orally delivered CPAP therapy and
improves user comfort.
Scented Seal
[0089] A scent may be applied to a cushion for a patent interface.
Using the mask cushion of FIGS. 18 to 21 as an example, a scented
seal will be described. The mask cushion 1104 is composed of an
inner foam cushion 1110 covered by an outer sealing sheath 1112.
The inner cushion 1110 is constructed of a resilient material for
example polyurethane foam. The outer sheath 1112 fits in place over
the cushion 1110, holding it in place. The sheath 1112 is secured
by a snap-fit to the periphery 1114 of the hollow body. The outer
sheath 1112 is constructed of a resilient material such as
silicone, but other appropriate materials may be used. Either the
inner cushion or outer sheath can be scented so as to mask the
natural smell of the materials these are made from. This also helps
to make use of the cushion and mask more pleasant for the patient
or user. Thus increasing the compliance of use of such a mask or
patient interface.
[0090] During the moulding of the inner cushion or outer sheath a
scent may be added via a dosing unit on the moulder before the
material making up the cushion of sheath is injected into the
mould. The scent therefore mixes with the material during moulding.
Alternatively, the scent may be blended with the raw materials for
the cushion or sheath. Or the cushion or sheath may be scented by
soaking a finished product, for example, an inner cushion or outer
sheath, or other type of seal for a patient interface, in a
solution. In particular, vanilla is a scent that would be
preferred. However, other scents could also be used.
[0091] Alternatively, a scent may be sprayed or otherwise applied
to a cushion, sheath or seal.
[0092] Vanilla would be a preferred scent to be used with a patient
interface cushion or seal as it has been shown that a high
percentage of the human population like or at least do not have an
aversion to the smell of vanilla.
[0093] In a preferred form a silicone seal, similar to that of the
outer sealing sheath of FIG. 18, would be scented with vanilla.
[0094] A scent may be applied to any type of seal for a patient
interface. An example of a patient interface where the seal and/or
cushion may be scented are the full face masks of co-pending U.S.
patent application Ser. Nos. 11/368,004 and 61/104,401 of Fisher
& Paykel Healthcare Limited, the contents of which are included
herein by reference. Another example of a patient interface where a
scent may be applied to the cushion and/or seal are the nasal
cannula of co-pending U.S. patent application Ser. Nos. 10/598,026,
61/082,877 and 61/052,362 of Fisher & Paykel Healthcare
Limited, the contents of which are included herein by reference.
Yet another example is a seal and/or cushion that may be scented is
that of the nasal mask of co-pending U.S. patent application No.
61/138,194 of Fisher & Paykel Healthcare Limited, the contents
of which are included herein by reference.
Seal with Antibacterial Properties
[0095] Similar to that above, an antibacterial solution may be
applied to a cushion for a patient interface.
[0096] In much the same way as detailed above in relation to adding
a scent to a cushion an antibacterial solution could be added to a
seal so as to give it additional antibacterial properties such that
a seal having this solution in it is less likely to retain
bacteria.
[0097] So as with the above scent the antibacterial solution may be
blended with raw materials making up the scent, may be added during
the moulding of the seal through a dosing unit or be impregnated by
soaking, for example.
* * * * *