Canadian Patents Database / Patent 2216791 Summary

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(12) Patent: (11) CA 2216791
(54) English Title: AIR BED WITH FLUIDIZED BEAD SURFACE AND RELATED METHODS
(54) French Title: LIT A MATELAS D'AIR ET A SURFACE FLUIDISEE DES BOURRELETS ET PROCEDES S'Y RAPPORTANT
(51) International Patent Classification (IPC):
  • A47C 17/00 (2006.01)
  • A47C 21/04 (2006.01)
  • A47C 27/00 (2006.01)
  • A47C 27/08 (2006.01)
  • A47C 27/10 (2006.01)
(72) Inventors :
  • VRZALIK, JOHN H. (United States of America)
  • LEININGER, PETER A. (United States of America)
  • HICKS, RONALD B. (United States of America)
(73) Owners :
  • HUNTLEIGH TECHNOLOGY LIMITED (United Kingdom)
(71) Applicants :
  • KINETIC CONCEPTS, INC. (United States of America)
(74) Agent: OSLER, HOSKIN & HARCOURT LLP
(74) Associate agent: OSLER, HOSKIN & HARCOURT LLP
(45) Issued: 2005-07-12
(86) PCT Filing Date: 1996-04-24
(87) Open to Public Inspection: 1996-10-31
Examination requested: 1997-09-29
(30) Availability of licence: N/A
(30) Language of filing: English

(30) Application Priority Data:
Application No. Country/Territory Date
08/428,689 United States of America 1995-04-25

English Abstract





A therapeutic patient treatment
bed (20) with features to enhance the
care and comfort of burn patients and
others subject to extensive recuperative
periods. Among the features are
patient engaging fluidized bead surfaces
(22) integral with the upper surfaces
(27) of air cushions (21) provided
by an air bed (20). Detachable
conformation of the fluidized bead
surfaces (22) is also provided.


French Abstract

Cette invention concerne un lit (20) destiné au traitement thérapeutique de patients, lequel possède des caractéristiques permettant d'améliorer tant les soins prodigués à des patients brûlés, ou à tout autre sujet ayant besoin de longues périodes de récupération, que leur confort. Parmi ces caractéristiques, on peut citer les surfaces fluidisées de bourrelets (22) entrant en contact avec le patient, lesquelles font partie intégrante des faces supérieures (27) des coussins d'air (21) que comporte un lit à matelas d'air (20). Cette invention prévoit également une configuration détachable desdites surfaces fluidisées (22) des bourrelets.


Note: Claims are shown in the official language in which they were submitted.



21

CLAIMS

What is claimed is:

1. A therapeutic patient treatment bed having an inflatable patient support,
wherein said inflatable patient support comprise:
an inflatable air cushion having an upper surface; and
fluidizable solid medium integrally associated with the upper surface of said
air cushion,
such that air used to inflate said air cushion also acts to fluidize said
solid medium.

2. The patient treatment bed as set forth in claim 1 wherein the fluidizable
solid
medium is contained by an air-permeable pouch positioned on the upper surface
of said air
cushion.

3. The patient treatment bed as set forth in claim 2 wherein said air cushion
includes an inflatable chamber and said pouch comprises a layer of air-
permeable fabric
positioned between said inflated chamber and a quantity of the fluidizable
solid medium.

4. The patient treatment bed as set forth in claim 2 wherein said pouch is
removably secured to the upper surface of said air cushion.

5. A therapeutic patient treatment bed comprising:
a plurality of inflatable air cushions collectively forming an inflatable
patient support,
at least one of said inflatable air cushions including a chamber and
comprising an air permeable
sheet positioned between said chamber and a quantity of fluidizable
microspheres, such that
air within said chamber is directed through said air-permeable sheet in a
manner which tends to
fluidize said microspheres.

6. The therapeutic patient treatment bed of claim 5, wherein:
said inflatable air cushion include an inflatable chamber defined by two types
of
material, including an air-permeable fabric and a relatively impermeable
second fabric; wherein
said air-permeable sheet is composed of said air-permeable fabric.


22



7. The patient treatment bed as set forth is claim 6 a second one of said
inflatable air cushions defines a second inflatable chamber and also a sheet
of air-
permeable fabric positioned between said second inflatable chamber and a
quantity of fluidizable
microspheres such that air inflating said said chamber is directed through the
associated air-
permeable fabric is a manner which tends to fluidize the second quantity of
fluidizable
microspheres.

8. The patient treatment bed as set forth in claim 6 wherein an air supply for
inflating the second inflatable chamber is controllable separate from the air
supply for inflating
the first inflatable chamber, thereby enabling a first flow of fluidizing air
for the first quantity of
fluidizable microspheres to be controlled separately from a second flow of
fluidizing air for the
second quantity of fluidizable microspheres.

9. The patient treatment bed as set forth in claim 8 further comprising mean
for
pulsating the first flow of air relative to the second flow of air.


Note: Descriptions are shown in the official language in which they were submitted.


CA 02216791 1997-09-29
WO 96133641 PCT/US96/OS704
1
s Air Bed with Fluidized Bead Surface and Related Methods
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION.
The present invention relates to therapeutic beds and, more particularly, to
therapeutic
beds of the type having an air cushion support together with an integral
fluidized bead surface.
2. BACKGROUND.
The care of patients requiring extensive recuperative periods presents many
extraordinary challenges which have not been adequately addressed in the past.
Not the least
of these challenges is providing a patient support surface that is both sturdy
and easy to use,
while simultaneously providing preventive therapy and intervention for the
numerous
complications associated with extended confinement to bed. Burn victims, for
instance,
typically require extremely low patient interface pressures, high air flow, as
well as lnw shear
forces. It is well-known in the art that two of the most ideal patient support
surfaces for the
immobile patient are low-air-loss beds and fluidized bead beds. Low-air-loss
bed and mattress
examples are described in U.S. Pat. Nos. 5,005,240 (KINAIR) and 5,022,110
(FIRSTSTEP).
2o Examples of bead beds are described in U.S. Pat. Nos. 4,564,965
(CLIIVITRON), 5,008,965
(FLUIDAlR), and 5,036,559 (ELEXIS).
Conventional bead beds typically include a bathtub-like tank filled with
medical-grade
silicone microspheres (or 'beads'. Each individual bead typically has a soda-
Iime core
encased within a silicone sphere approximately 100 microns in diameter. A
diffuser board is
2 s positioned horizontally at the base of the tank, separating two
compartments within the tank --
an upper compartment which contains the beads and a smaller, Iower compartment
which
serves as a plenum chamber filled with air for fluidizing the beads. With
appropriate blowers
and temperature control systems, air is blown into the plenum chamber, from
which the
SUBSTITUTE SHEET (RULE 26)


CA 02216791 1997-09-29
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2
s pressurized air is forced upwardly through the difruser board and fizrther
(often in bubble-like
manner) through the beads, giving the beads a liquid-like quality. A filter
sheet is draped over
the top of the tank to contain the beads while allowing the upward passage of
air. The patient
can lie either directly on the filter sheet or on a second cover sheet.
Despite the liquefied state ,
of the beads, the patient remains buoyant because of the relative density of
the beads.
l o Although such bead beds may actually provide the most therapeutic surface
from the
standpoint of pressure and microclimate at the patient interface (i.e.,
interface between patient
and mattress), conventional bead beds have many drawbacks. Traditionally, bead
bed
manufacturers have thought that a significant depth of beads was required in
order to provide
an adequate patient support with good fluidization. Fluidizing the resulting
volume of beads
is inherently required heavy-duty blowers and related equipment, not to
mention the extra
structural requirements for the frames of such beds. Conventional bead beds
are extremely
heavy (approximately 2,000 pounds), which not only makes them difficult to
maneuver, but
also requires that they be used only in buildings having extremely sturdy
support. Second-
story placement in wood-frame houses is typically avoided without assessment
by a structural
2 o engineer. The poor maneuverability and excessive weight may also present
risks to caregivers
who are not properly trained in safely maneuvering such heavy objects.
Handling a patient in a conventional bead bed is also plagued with difficulty,
largely
because caregivers must reach down into the tank and lift the patient up or
out for handling.
The teaching of U.S. Pat. No. 5,008,965 attempted to address this situation by
providing
25 separate air bladders within the bead compartment for displacing the beads
upwardly, hence,
lifting the patient relative to the tank. Still others, such as illustrated in
U.S. Pat. No.
5,036,559 (ELEXIS), have attempted to address the problem by providing
deflatable or
otherwise collapsible tank walls instead of the traditionally rigid walls.
Related difficulty is
SUBSTITUTE SHEET (RULE 26)


CA 02216791 1997-09-29
WO 96133641 PCT/US96/05704
3
faced by the patient who is attempting to sit up in such beds. Although foam
wedges and the
like are often used to help prop up the patient, props present the obvious
downfall of
interfering with the therapeutic benefits of the bead surface. Using props
also renders such
products more difficult to manipulate than conventional hospital beds which
have automatic
bed functions such as head-up, Trendelenberg and the like.
to Air beds, on the other hand, eliminate many of these problems. Not only are
the
mattresses ofthe air beds lighter due to the lighter supporting medium (i.e.,
air versus beads),
but lighter-duty supportive equipment and structural members are needed as
well. Moreover,
air beds permit many of the user-friendly features of standard hospital beds,
such as sit-up,
Trendelenberg, and the like, not to mention retractable side rails and
radioluminescence. The
extra space beneath the patient surface also allows not only for extra
storage, but also for
adding accessory therapeutic units such as percussion and hyper-hypothermia
treatment.
Many other advantages and disadvantages of low-air-loss beds and air fluidized
bead
beds will be understood by those of ordinary skill in the art, especially
after reviewing this
specification.
2 o SUMMARY OF THE INVENTION
It is a fundamental object of the present invention to improve over the prior
art,
including to provide a therapeutic patient treatment bed and related methods
which facilitate
the care and comfort of bed-ridden patients, while simultaneously addressing
the complications
associated with immobility.
This and other objects are addressed by providing a therapeutic patient
treatment bed
wherein the patient support surface comprises an air cushion with integral
fluidized bead
surfaces. The beads may be fluidized by the same air flow as is utilized for
inflating the patient
support air cushion. Unlike many prior bead beds, the invention described
herein allows the
SUBSTITUTE SHEET RULE 26)


CA 02216791 1997-09-29
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4
patient support surface to be positioned as desired, providing a lightweight,
full-featured
fluidized bead bed. Moreover, because air flow can be compartmentalized into a
plurality of
air bags or cushions, each with independent bead surfaces, the present
invention also enables a
wide variety of additional surface therapies not previously available with
bead beds, including ,
pulsation, percussion, and kinetic therapies. The fluidized bead surfaces may
also be
z o detachable for facilitating infection control procedures.
Many other objects, features, variations and advantages of the invention will
be evident
from a review of the further descriptions herein, particularly when reviewed
by one of
ordinary skill in the art with the benefit of the accompany drawings, appended
claims and the
prior art.
i5 BRIEF DESCRIPTION OF TFIE DRAWINGS
FIG. 1 is a perspective view of a patient treatment bed 20 (absent its cover
sheet)
configured and operatively inflated for typical use, which comprises a
presently preferred
embodiment of the present invention.
FIG. 2A is a perspective view of an air bag 21 of the bed 20 shown in FIG. 1.
2 o FIG. 2B is a partial cross-sectional view of the airbag 21 shown in FIG.
2A.
FIG. 3A is a partially-exploded perspective view of an air bag 171, which is
an
alternate embodiment of the air bag 21 shown in FIGS. 2A-B.
FIG. 3B is a partial cross-sectional view of the air bag 171 shown in FIG. 3A,
including its fluidized bead pouch 172, taken along lines 3B-3B in FIG. 3A..
25 FIG. 4A is a partially-exploded perspective view of an air bag 121, which
is a second
alternative of the air bag 21 shown in FIGS. 2A-2B.
FIG. 4B is a cross-sectional view of the airbag cap 30 as shown in FIG. 4A.
SUBSTITUTE SHEET (RULE 26)


CA 02216791 1997-09-29
WO 96/33641 PCT/US96/05704
5 FIG. 4C is a partial cross-sectional view of the main part 29 of the air bag
21 shown in
FIG. 4A.
FIG. 4D is a partial cross-sectional view of an alternative embodiment 29' of
the main
part 29 shown in FIG. 4C, from the same perspective as shown in FIG. 4C.
FIG. 5 is a perspective view of an alternate embodiment 320 of the invention.
Zo FIG. 6 is a more detailed perspective view of the mattress 320 of the
alternate
embodiment shown in FIG. 5, absent its frame 319 and cover sheet 380.
FIGS. 7A and 7B are views of the unassembled upper wall 27 and filter sheets
41 and
42 of bead pouch 22.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Although most aspects of the invention described and claimed herein could be
embodied in many different types of beds, mattresses and/or cushions, the bed
20 shown in
FIG. 1 is considered to be a presently preferred embodiment of that invention.
Referring to
FIG. 1, there is shown a patient treatment bed 20 that is uniquely suited for
treatment of burn
patients and other patients subject to extensive recuperative periods. Bed 20
includes a frame
19 supporting a plurality of patient support air bags 21, which are uniquely
adapted with bead
pouches 22. One fairly basic aspect of the invention can be embodied in one or
more cushions
such as patient support air bags 21, operatively associated with one or more
fluidized bead
containment pouches 22 and means for fluidizing the same, all of which may or
may not be
mounted on a frame such as frame 19.
2s One advantage of the invention is that it can be implemented as a
relatively simple
upgrade to a pre-existing air support. Typically, the only change needed will
be to replace one
or more of the air cushions of the pre-existing support with new cushions that
are specially-
adapted to implement the present irwention. In some cases, however, it may be
that additional
SUBSTITUTE SHEET (RULE 26~


CA 02216791 2002-11-O1
6
blower capacity is needed due to the relatively large amount of air required
to fluidize the
bead pouches 22 as compared to the amount of air that may be needed to sustain
inflation of
the pre-existing support. Those of skill in the art will understand how to
increase blower
capacity, such as by adding an additional blower or redirecting existing
blowers. The term
'host platform" is used in this description to refer to the pre-existing
support. Modifications to
the host platform may be described in detail, whereas unmodified details will
be described
only to the extent desired for reference.
The host platform 20 may be any of a number of commercially available patient
air
supports, preferably low-air-loss patient treatment beds. Host platform 20 of
the preferred
embodiment comprises a low-air-loss bed presently commercialized under the
trademark
'KINAIR III," commercially available from Kinetic Concepts, lnc. of San
Antonio, Texas
('KCf). 'fhe KiNAIR Ill bed is described in substantial detail in U.S. Pat.
No. 5,005,240,
dated April 9, 1991. Other suitable host platforms include, but are not
limited to, those
marketed by KCI under the trademarks 'HOMEKAIR," 'THERAPULSE" and 'BIODYNE IL"
All of these platforms are commercially available from Kinetic C'.oncepts,
Inc. The
'fHERAPULSE bed is described in substantial detail in U.S. Pat. No. 5,044,029,
dated
September 3, 1991. The BIODYNE II bed is described in substantial deiail in
U.S. Pat. No.
5,142,719, dated September l, 1992. Other host platforms might include
wheelchairs with
therapeutic air cushions or stand-alone therapeutic air mattresses mounted on
any desired
support.
As suggested above, the principal difference between bed 20 and a commercially
available KINAIR III bed is the adaptation of its air bags 21 to include
fluidizable bead
pouches 22. A simple form of such an adapted air bag 21 can be made by cutting
a rectangular
hole in the upper surface of an existing KINAIR III air bag and sewing a
similarly-shaped, air-


CA 02216791 2002-11-O1
permeable bead pouch 22 over the hole. An air bag 21 made in such manner is
shown in Figs.
2A & B, as part of a presently preferred embodiment of the invention.
Conventional stitching
techniques can be used to provide a smooth outer surface for the adapted bag
21. For instance,
although it is stated to sew the bead pouch "over" the hole, it will be
understood by those of
skill in the art that an acceptable technique for minimizing exposed edges
would be to sew (or
otherwise attach) the pouch from the inside of air bag 21, around the
perimeter of the
rectangular hole 39 in the air bag's upper surface 27. Conventional seam-
sealing techniques
can also be used to minimize toss of air through the seams 40a-40d, as well as
any other seams
in bag 21, to minimize any unnecessary air leaks in the air bag 21. Such a
construction enables
the air bag 21 enclosure to serve as an effective plenum chamber for
fluidizing the beads
within the bead pouch 22; the space 48 enclosed by air bag 21 is, hence,
referred to as the
"plenum space" 48.
Refernng to FIGS. 2A & B, each adapted air bag 21 includes bead pouch 22
formed
integally therein. Such integral construction ensures simplicity of
manufacture and use, while
minimising any excessive loss of air, as might be more likely with a two-part
construction.
The air bag 21 can be disinfected through laundering With a dilute bleach
solution in the same
manner as conventional air bags. Due to the inclusion of the bead pouch 22,
adequate drying
of the air bag 21 may require operative connection of the air bag 21 to a host
platform. Such
operative connection helps dry the beads by virtue of the air blowing through
beads 200.
Although the exact length of time needed to dry the beads 200 may vary, twenty-
four hours
will generally be more than adequate. The drying time should be however long
it takes to dry
the beads so they can be adequately fluidized, while also respecting any
infection control
concerns.


CA 02216791 2002-11-O1
g
One alternative embodiment of air bag 21 is described further herein as air
bag 171,
with reference to FIGS. 3A & B. Such alternative air bag 171 utilizes a bead
pouch 1?2 that is
adapted to be removed from a pocket 198' in the end wall 17~ of the air bag
171. The pouch
172, therefore, can be removed and disinfected or disposed of separate from
any low-air-loss
components. Another alternative embodiment of air bag 21 is described further
herein as air
bag 121, with reference to FIGS. 4A-D. Such alternative air bag 121 also
utilizes a two-part
construction for its bead pouch 122. Air bag 121 is different, though, in that
its bead pouch
122 is embodied in a removable cap 130 for air bag 121.In such alternative,
the bead
containment pouch 122 is removed from the air bag 121 by removing the cap 130
as a whole,
so that the pouch 122 can then be disinfected or disposed of separate from any
low-air-loss
components. Other embodiments are also disclosed.
Each of the air bag embodiments 21, 171 and 121 are made from the same basic
fabrics -- a low-air-loss material and a filter sheet material. The low-air-
loss material in the
preferred embodiment is a polymer-coated nylon material commercially available
under the
IS trademark 'GORE-TEX" from W.L. Gore & Associates, Inc. of Elkton, Maryland.
Such
lowair-loss material has very little air permeability yet has a moisture vapor
transmission rate
in excess of 4700 glm2124 hours. In the preferred embodiment, the filter sheet
fabric is
constructed of 63-micron monofilament polyester fiber thread with 40-micron
nominal mesh
opening and 15% open area. The filter fabric is commercially available from
Tetko, Inc. of
Briarcliff Manor, NY. One possible alternative that might be considered is to
use a similar
multifilament fabric rather than the monofilament. Other suitable alternatives
will be evident
to those of skill in the art.
Regarding the construction of the air bag embodiments 21, 171 and 121, there
are
several common elements. Although most of such common elements are also common
with


CA 02216791 2002-11-O1
9
the commercially-available KINAIR III air bags, beef reference is made to each
of such common
elements (referring to reference numerals used in FIG. 2A). Air bag 21, to
begin with, is formed
to have the general shape (when inflated) of a rectangular prism, as shown in
FIG. 2A. Air bag 21
has six generally rectangular walls 23-28, which may be considered as three
pairs of opposed
similar walls: opposite side walls 23 and 24, opposUe end walls 25 and 26, and
opposite top and
bottom walls 27 and 28. Each of such walls 23-28 is formed primarily of the
iow-air-loss material
referenced above, cut in pieces that are stitched (or otherwise joined) to
adjacent pieces along
their adjoining edges. As will be understood by those of ordinary skill in the
art, particularly with
reference to a commercially-available KINAIR III air bag, certain walls may
actually be formed
from the same piece of material as another wall, while other walls may be
formed of a
combination of one or more pieces of material. The edges between two adjoining
walls, hence,
may not in actuality constitute seams between fabric pieces. The sheet of
material which forms
the top wall 27. for instance, actually extends beyond each of its edges 27a-
27d shown in F1G.
2A. Fabric-gathering seams and conventional stitching techniques are used to
generally form each
1~ of the four corners 27e-27h of upper wall 27. That same piece of fabric
which forms upper wall
27, further, extends partially down each of the opposite side walls 23 and 24
and each of the
opposite end walls 25 and 26 to a seam (not shown) with an adjoining piece of
fabric slightly
above the level of baffle 34. Again, such sewing techniques and the general
construction for the
various walls 23-28 of air bag 21 will be evident to those of ordinary skill
in the art, particularly
with reference to commercially-available air sacs. It is also noted that in
certain alternative
embodiments it may be desired to form the air cushions in different shapes,
such as the cutout
shape of the BIODYNE air sacs, or the relatively flat (or 'low profile') shape
of the air sacs used
in products such as the DYNAPULSETM product, also available through Kinetic
Concepts, Inc.


CA 02216791 2002-11-O1
Still referring to common elements of the air bag embodiments 21, 171 and 121,
as well
as the KINAIR III air bags, each air hag 21, 171 and 121 also has a post 43
and an air inlet 44
operatively secured to the bottom wall 28 thereof, as is standard for KINAIR
IlI air bags, for
attachment to the host platform 20. Such hardware 43 and 44 are standardly
employed in a
5 manner which allows entry of air into a space 48 defining the largest-volume
portion of the air
bag 21, such air being blown by blowers such as standardly included in the
host platform 20.
Each air bag 21 further comprises a baffle 34, also constructed of low-air-
loss fabric, although
less costly alternative fabrics may be desired as air permeability and low
skin shear benefits are
not necessary for baffle 34. Baffle 34 functions to ensure the desired
prismatic shape of the
10 inflated bag 21 (i.e., that of a rectangular prism). The baffle 34 is sewn,
or attached by other
equivalent means, at its edge 35 to the inside surface of the front side wall
23 of the air bag 21.
The baffle 34 is similarly sewn, or attached by other equivalent means, at its
edge 36 to the inside
surface of the rear side wall 24 of the air bag 21. The end-to-end length of
baffle 34 as measured
from edge 37 to edge 38 is sufficiently less than the end-to-end length of air
bag 21, as measured
from end 25 to end 26. That shorter length allows substantial air flow around
the baffle. Said air
flow is as depicted by arrows (including arrows 33a-c in FIGS. 2A & B). The
preferred
embodiment provides a minimum 4-inch opening between end wall 25 and edge 37
as well as end
wall 26 and edge 38.
Further understanding of the hardware 43-44 and sewing techniques utilized in
the
preferred embodiment may be gathered to some extent with reference to U.S.
Pat. No. 5,062,171,
dated November 5, 1991.
Referring to FIG. 2B, there is shown a sectional view of a fluidized bead
containment
pouch 22 (viewed on the vertical plane 2B-2B indicated in FIG. 2A). 'fhe bead
containment
pouch 22 is substantially rectangular from above (rectangular shape generally
visible in Fig.


CA 02216791 2002-11-O1
11
2A) and comprises rectangular top and bottom filter sheets 41-42. Unless
sheeas 41 and 42 can be
readily made together as a seamless pouch, sheets 41 and 42 are sewn or
otherwise joined to each
other around their perimeters (i.c., along edges 40a-40d) in a substantially
sealed manner so as to
form a substantially closed pouch for containing beads 200. In the preferred
embodiment, filter
sheets 41 and 42 are constructed of the same filter sheet fabric as described
previously herein. By
making pouch 22 seamless or by providing sealed seams 40a-d, leakage of beads
200 from pouch
22 can be minimized. Once filled with beads 200 to the desired extent and
sealed closed, the
pouch 22 is then sew (or otherwise attached) to the upper wall 27 of air bag
21, around the
perimeter of hole 39.
The preferred size of upper and lower filter sheets 41 and 42 (and, hence,
pouch 22) will
be best understood from the description of the preferred method for making
pouch 22. With
reference to FIGS. 7A & 7B, there is shown a plan view of the cut-outs for the
upper wall 27 and
bead pouch 22, respectively. As mentioned, the rectangular hole 39, which is
cut out of upper
wall 27, is a substantially rectangular hole. The preferred dimensions of such
hole are 5 inches
(along edges 39c&d of hole 39) by 23 inches (along edges 39a&b of hole 39).
The pouch 22
begins at a single piece 86 of filter sheet fabric cut in the shape as shown
in FIG. 7B. The overall
dimensions of piece 86 arc nominally 49 inches (in length) by 61/2 inches (in
width), although
lower sheet 42 is tapered in its primary dimension to 4 inches. The dimensions
401 - 406 of
piece 86 are 15112, 4112, 41/2, 4, 61/2 and 24112 inches, respectively. Once
piece 86 is cut as
shown in FIG. 7B, the piece is folded along its center line 87. Then, edge 41a
is sewn (inside out)
to edge 42a and edge 41b is sewn (inside out) to edge 42b, to give the pouch
22 its basic shape.
Then, the assembly is pulled right side out and filled with beads 200 (not
shown in FIG. 7B)
through an opening formed between edges 41c and 42c, after which the same
edges 41c and 42c
are sewn and sealed. The seams formed by the unions of edges 41a-c and 42a-c,
and a


CA 02216791 1997-09-29
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12
s final edge formed by the fold 87, are then sewn and sealed to upper wall 27
along the
perimeters of hole 39. The result produces a bead pouch 22 that is slightly
tapered along its
midsections. Given the amount of material used by seams (approximately 1/4
inch for each '
seam), the final width of lower filter sheet 42 which is exposed to the beads
200 is ,
approximately 3 inches at its narrowest point and 5 inches at its longitudinal
ends adjacent to
1 o seams 40c&d. The remaining dimensions of FIGS. 7A&B are as shown therein.
The resulting size is generally such that in every air bag 21 on bed 20
included a pouch
22, then the entire patient could be supported on the bead pouches 22. Certain
ones of air
bags 21 may have differently sized pouches 22, or may not have pouches at all.
In the bed 20
illustrated in Fig. 1, for instance, head air bags 98 have shorter pouches
(only about 10 inches
1s long), and the last air bag 99 does not have a pouch 22 at all. Further,
air bags with and
without pouches 22 can be mixed and matched along the length of the bed 20 to
achieve a
desired surface. For patients with local burns, for instance, the fluidized
bead surface may be
limited to that region of the patient where the burn is located, while the
rest of the patient is
supported on conventional KinAir III air bags. In other cases, the bead
surface may be limited
2 o to the seat section as that is where weight concentration is greatest. In
any case where
pouches 22 are included in a given air bag 21, however, the upper sheet 41 is
preferably about
2 inches wider than the Lower sheet 42, for reasons mentioned elsewhere
herein.
The beads 200 contained in each bead pouch 22 are preferably medical grade
microspheres of the type commonly employed in air fluidized bead beds. Such
beads range in
2s size from 50 to 150 microns in diameter and are commercially available from
a number of
. sources, including Potters Industries, Inc. of Carlstadt, New Jersey. A
single bead pouch 22
preferably contains about a two pounds of beads, although quantities of bead
material from '/4
to 30 pounds or more per air bag may be suitable. The bead pouch 22 is also
not completely
SUBSTITUTE SHEET (RULE 26)


CA 02216791 2002-11-O1
13
filled, so that the beads are free to fluidize therein. Consequently, when air
flows through bead
pouch 22 without a patient supported thereon, the upper filter sheet 42 tends
to billow
upwardly, forming an air space 201 above the beads 200.
The pouch 22, hence, is integrated with air bag 21 in a manner that encourages
air
flow from space 48, through pouch 22, tending to fluidize any quantity of
beads 200 within
pouch 22. Because the low-air-loss GORE-TEX fahric has very low air
permeability, the air
that inflates the air bag 21 tends to flow, more particularly, from plenum 48,
through the lower
filter sheet 42, through the beads 200 and excess space 201, and on through
the top filter sheet
41, as suggested by arrow 33c. By using the same air for bead fluidization as
is used to inflate
the air bag 21, greater fluidization is achieved in those pressure zones in
which air bags are
inflated to higher pressures, which usually occurs with those air bag zones
supporting heavier
body portions (such as a patient's seat section). Hence greater fluidization
is provided where it
tends to be needed most -- beneath the locations where the interface pressures
are also
greatest.
It is also noted, however, that lower filter sheet 42 may require some degree
of air
flow restriction in order to prevent excessive loss of air from within air bag
21. The balance of
the amount of air flow that will be desired through lower f7lter sheet 42 will
depend on a
variety of circumstances, including the blower capacity of the host platform
20, the volume of
beads 200 in each air bag 21, and the number of air bags 21 which are adapted
with bead
pouches 22. In one preferred embodiment, it has been found that air-
impermeable strips
89a&b may be adhered to the outer surface of lower filter sheet 42 to reduce
and concentrate
air flow through lower filter sheet 42. Such strips 89a&b are preferably
composed of
commercially available sealing tape such as is used for waterproofing grommets
in the clothing
industry. Suitable sealing tape is a'/<-inch T'eflonT"' sealing tape
commercially available through


CA 02216791 1997-09-29
WO 96/33641 PC'TIUS96/05704
14
s the W. L. Gore Company. Strips 89a&b (and similar strips sealing seams
40a&b) preferably
around the entire length of bead containment pouch 22 on the lower surface of
lower filter
sheet 42. Such configuration of sealing strips 89a-d leaves three sections 88a-
c of lower filter
sheet 42 unobstructed for free flow of fluidizing air therethrough. Due to the
3-inch width of
lower filter sheet 42, sections 88a-c end up being three strips of
unobstructed filter sheet
1o running the length of bead containment pouch 22. Each of strips
corresponding to sections
88a-c are approximately '/a-inch wide, although that width dimension will
flare toward the
ends 40c and 40d of bead containment pouch 22 as the bead containment pouch
itself flares as
well.
It is noted that once the air has passed through pouch 22, its direction of
flow is
15 determined based on other factors. For instance, if a conventional, high-
air-loss cover sheet is
used, some of the fluidizing air will pass through the cover sheet while the
remainder will be
diverted to the sides of the bed 20 by that cover sheet. If a cover sheet is
not used, then more
of the fluidizing air would tend to rise upwardly around the patient's body.
It is also noted that the profile shape of the pouch 22 (i.e., the cross-
sectannal shape
2 o such as shown in Fig. 2B) depends on a variety of factors. Such factors
include but are not
limited to the size of the bead pouch 22, the relative porosity of the filter
sheets 41 and 42, the
air pressure within plenum space 48, the quantity of beads 200 within pouch
22, and the
patient weight. In many cases, the bead pouch 22 tends to arch upwardly due to
the pressure
within air bag 21, in contrast to the cigar-like shape shown in Fig. 2B. Two
practical concerns
2 s with this occurrence are (i) that the beads 200 might migrate downward at
the sides of the
pouch 22 due to gravity, and (ii) that the arching might restrict free
fluidization =by
compressing the beads between the upper and lower filter sheets 41 & 42. One
contemplated
way of reducing such concerns is the inclusion of a vertical baffle (not
shown) spanning
SUBSTITUTE SHEET (RULE 26)


CA 02216791 2002-11-O1
between the lower filter sheet 42 and the horizontal baffle 34, in the same
general manner as
illustrated in Fig. 4D. Another technique that is preferred is to make the
upper filter sheet 41
wider and longer than the lower sheet 42 (approximately 2 inches in each
dimension) so that the
lower sheet 42 tends to be more taut (and, hence, less arched) than the upper
sheet 41. Yet
5 another technique is to increase the volume of the beads 200 in a given air
bag 21, such as by
starting the bead pouch 22 at the level of baffle 34, with beads filling up
roughly the entire upper
third of the air bag 21.
Although simple, the construction of air bag 21 might be found to be less than
ideal
for disinfecting on a routine basis. Referring to FIGS. 3A-4D, alternate
embodiments of air
10 bag 21 are shown which allow detachment of bead pouch 22 (or its
equivalent) so that the
bead containment pouch may be disinfected separately.
The first of such alternatives is shown in pigs. 3A & B as air bag 171. Air
bag 171 is
adapted with a removable bead pouch 172. The removable pouch 172 consists only
of its
upper and lower filter sheets 191 and 192 and the beads 200 contained
therehetween. Rather
15 than being permanently sewn to air bag 171, pouch 172 is inserted within
(and removable
from) a pocket 198' near the upper wall 177 of air bag 171. Access to the
pocket 198' is
provided through an opening 199 in the end wall 175 of the air bag 171. for
minimizing loss
of air pressure through opening 199, the opening 199 may be covered and/or
sealable by a
VelcroT"' flap (not shown) or the like. The pocket 198' is formed of two
layers of filter sheet
material 197 and 198 just beneath the upper wall 177 of the air bag 171.
Layers 197 and 198
are joined by conventional techniques along the opposite edges 177a and 177b
of upper wall
177 to form pocket 198'. 'fhe upper wall 177 is also provided with a
rectangular filter sheet
panel 189 for allowing free flow of air through bead pouch 172. An alternative
of air bag 171
excludes the upper filter sheet layer 197 of pocket 198'.


CA 02216791 1997-09-29
WO 96/33641 PC'T/LTS96/05704
16
s With such construction, the pouch 172 can be removed and disinfected or
disposed of
separate from the low-air-loss components of air bag 171. Such low-air-loss
components can
then be disinfected using standard laundering techniques for air bags. The
bead containment
pouch 172 may be disinfected by infection control techniques which are
standard and well-
known in the art for fluidized bead systems. Such infection control procedure
may involve
1 o destroying the filter sheet layers 191 and 192 of the pouch 172 and
pouring the beads 200
through a sieve screen into a conventional decontamination tank.
Decontamination can then
be achieved by a thermal process of heating the beads to 122°F for at
least 24 hours. Further
benefits of such removable conformation of bead pouch 172 will be apparent to
those of skill
in the art.
1 s A second basic type of alternative to air bag 21 is shown in Figs. 4A-C as
air bag 121.
Like air bag 171, air bag 121 also has a two-part construction adapted with a
removable bead
pouch 122 to facilitate infection control. The removable pouch 122, however,
is embodied in
a removable cap 130 that fits over the top of a main part 129 of air bag 121.
The main part
129 can be disinfected through laundering in the same manner as with
conventional air bags,
2 o and the cap 130 can be disinfected separately. Although the particular
technique used for
disinfecting the cap should be chosen based on the effectiveness of each
technique, it is
presently thought that adequate disinfection may be achieved by placing the
entire cap 130 into
a conventional microsphere decontamination unit, together with a separate bead
lot. Such a
decontamination is intended to raise the temperature of the cap above
120°F for more than a
25 24-hour period. Other disinfection techniques, such as chlorination, gamma
radiation and/or
autoclaving, may be considered as additional alternatives.
The main part 129 of air bag 121 is much like the construction of a standard
KinAir III
air bag, except that the main part 129 includes a filter sheet panel 147 and
Velcro tabs 131a-d.
~51~8ST1TUTE SHEET (RULE 26)


CA 02216791 2002-11-O1
17
Cap 130 includes the bead containment pouch 122 and Velcro tabs 132a-d. 'The
shape and
construction of cap 130 is such that it fus snugly over the main part 129 when
the main part
L29 is inflated, with tabs 132a-d positioned to mate with tabs l3la-d for
releasably securing
the cap 130 in place. Once so positioned, cap 130 positions bead pouch 122
over the fflter
sheet panel 147, so that air escaping through panel 147 is directed through
pouch 122, tending
to fluidize the beads 200 therein. To optimize fluidization, Velcro tabs 132a-
d and 131a-d may
be enlarged or replaced with other connections providing a better seal.
Improving such seal
ensures that the only significant escape for air from the air bag 121 is
through bead pouch 122.
The size of the panels 147 and pouch 122 is much the same as that of the pouch
22 in the first
embodiment, although panel 147 is preferably narrower than pouch 122.
With reference to FIG. 417, an alternative construction of main part 129 is
shown,
designated as 129'. Particularly, main part 129' includes a vertical baffle
149 coextensive with
the conventional horizontal baffle 227'. Vertical baffle 149 spans is joined
by stitching
between the centerline 150 of panel 147 to form a trough-like crease along the
top of main part
129'. Such trough-like crease not only tends to bias beads 200 toward the
centerline 150, but
its stitched joinder increases fluidization (by introducing stitch holes in
panel 147) along the
centerline 150 where the beads 200 are drawn.
Referring to FIGS. 5 ltc 6, there is shown an alternate embodiment 320 of the
bed 20
shown in FIGS. 1-2B. Bed 320 generally consists of an air mattress 318 (and
related
components) mounted on a standard bed frame 319. The mattress 318 is sectioned
into three
basic support cushions 318a, 318b, and 318c, as is standard for a variety of
mattress and
mattress overlay products. Each basic support cushion 318a, b or c is supplied
with air flow
from a standard air supply unit 315 through corresponding supply hoses 316a-e.
Each cushion
includes a series of six vertical baffles (not numbered) to ensure retention
of a relatively flat


CA 02216791 2002-11-O1
18
shape. Examples of such patient support mattress systems are found in the
commercially
available FIRSTSTEP SELECT''"", HOMEKAIR DMST"' and DYNAPULSET'" products,
each
commercially available through Kinetic Concepts, Inc_ The particular system
illustrated in
Figs. 5 & 6 is a modified FIRSTSTEP SELECTTM unit. As with the previously-
described
embodiments, the mattress 318 is substantially the same as the commercial
version of that
product. The only significant difference being the addition of lluidizable
bead containment
pouches 322a-c and any additional blowers that might be needed (if any) to
fluidize the same.
As will be evident to those of skill in the art, the size of the bead
containment pouches 322a-c
can be varied as desired. For instance, in 1'ig. 6, it is shown that the size
of the pouch 322b
positioned for supporting the seat section of a patient is larger than the
other two pouches
322a&c . Thus, greater therapy can be provided in the seat section (or in any
other areas)
where the therapeutic need is greater. The particular method of adapting the
cushions 321a-c
with an appropriate number of bead containment pouches 22 is not critical but
will be
understood from an understanding of the preferred embodiment of air bag 21.
Another
variation (not shown) of bed 320 can be made by replacing substantially all of
the top surface
of the mattress 318 with a single fluidizable bead pouch.
The invention described herein allows combination of a fluidized bead patient
support
surface, well-known in the art to be an ideal patient support surface, with
the advantages of
low-air-loss beds. Such advantages will be evident to those skilled in the art
and include, but
are not limited to, vertical and/or articulated displacement of the patient
support surface, side
to side rotation of the patient, automatic percussion of the patient's chest
area, and built-in
scales, all of which are welt-known in the art and may be described in the
literature available
for the commercial products KINAIR III, HOMEKAIR, THERAYULSE and EIODY1VE II.


CA 02216791 1997-09-29
WO 96/33641 PCTlUS96105704
19
s Unique advantages afforded by each of the many l3os'sible host platforms 20
for
implementation of the invention described herein will also be apparent to
those skilled in the
art. Said advantages will generally vary with the basic capabilities of the
chosen host platform
20. One of the more interesting has been found by using air bags like air bag
21 to replace the
air bags of a THERAPULSE bed, commercially available through Kinetic Concepts,
Inc.
io Utilization of the THERAPULSE bed as host platform 20 allows the caregiver
to establish
various pressures within air bags 21 corresponding to differing regions of the
patient's body,
and also allows automatic pulsation of bead fluidization. A caregiver can,
thus, vary the level
of fluidization for different parts of the body, and also pulse that
fluidization as well. Although
the air bags 21 as a whole generally become softer at lower pressures, the
beads 200 generally
15 become more stiff with lower degrees of fluidization. Hence, pulsing the
fluidization with the
THERAPULSE as host platform 20 will cause the beads 200 in the air bags 21 to
vary from
soft, to stiff, to soft, and so on. Not only will adjacent air bags 21 vary in
opposite phase (as is
normal for THERAYULSE pulsation), but stiffness of the bead pouch 22 surface
will vary in
opposition to the air pressure in the air bag 21 as a whole.
2 o Another alternative embodiment, which is not shown in the drawings, is
adapted to
provide a dedicated air flow for purposes of fluidizing the beads 200 in each
air bag 21. The
concept for this alternative is to allow separate control of the air supply
directed to the plenum
used for fluidizing the bead pouch 22 and to reduce the size of that plenum
chamber. With a
smaller, separately controlled plenum, the pressure of the air fluidizing the
beads can be
2 s increased to achieve greater fluidization without increasing the pressure
of the air bag 21 as a
whole. To do this, a separate inflatable chamber is defined within air bag 21
directly adjacent
the bead pouch 22. The inflatable chamber serves as the plenum for fluidizing
the bead pouch
22, and a separate air supply is directed to that plenum. The construction of
the separate
SUBSTITUTE SHEET (RULE 26)


CA 02216791 1997-09-29
WO 96/33641 PCT/US96/05704
s plenum within the air bag 21 would be designed in any manner desired,
although the simplest
approach uses the same low-air-loss material as the remainder of air bag 21.
The separate
dedicated air flow might be directed through a separate air inlet for the air
bag 21. A
collapsible air conduit within air bag 21 would also serve to direct the flow
of air from the
second air inlet to the dedicated plenum. Although conventional air conduit
may be suitable, a
1 o fabric conduit (also formed of sealed low-air-loss material) may be
adequate to serve this
purpose. By providing a separate air flow dedicated to fluidization, the
inflation of the air bag
21 as a whole could, thus, be varied independently from the fluidization of
the bead pouch 22.
Similar adaptations of the other alternative embodiments could also be made.
Many other alternatives, variations and modifications of the present invention
will be
15 evident to those of skill in the art and are contemplated to fall within
the scope of the present
invention. Although the present invention has been described in terms of the
foregoing
preferred and alternate embodiments, this description has been provided by way
of explanation
only and is not to be construed as a limitation of the invention, the scope of
which is limited
only by the following claims and any amendments thereto.
SUBSTITUTE SHEET (RULE 26)

A single figure which represents the drawing illustrating the invention.

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Administrative Status , Maintenance Fee  and Payment History  should be consulted.

Admin Status

Title Date
Forecasted Issue Date 2005-07-12
(86) PCT Filing Date 1996-04-24
(87) PCT Publication Date 1996-10-31
(85) National Entry 1997-09-29
Examination Requested 1997-09-29
(45) Issued 2005-07-12
Lapsed 2016-04-25

Abandonment History

There is no abandonment history.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Request for Examination $400.00 1997-09-29
Filing $300.00 1997-09-29
Maintenance Fee - Application - New Act 2 1998-04-24 $100.00 1998-03-17
Registration of Documents $100.00 1998-09-23
Registration of Documents $100.00 1998-09-23
Registration of Documents $100.00 1998-09-23
Maintenance Fee - Application - New Act 3 1999-04-26 $100.00 1999-04-26
Maintenance Fee - Application - New Act 4 2000-04-25 $100.00 2000-04-20
Maintenance Fee - Application - New Act 5 2001-04-24 $150.00 2001-04-10
Maintenance Fee - Application - New Act 6 2002-04-24 $150.00 2002-03-28
Maintenance Fee - Application - New Act 7 2003-04-24 $150.00 2003-03-31
Registration of Documents $100.00 2003-07-07
Maintenance Fee - Application - New Act 8 2004-04-26 $200.00 2004-04-26
Maintenance Fee - Application - New Act 9 2005-04-25 $200.00 2005-03-17
Final Fee $300.00 2005-04-26
Maintenance Fee - Patent - New Act 10 2006-04-24 $250.00 2006-03-06
Maintenance Fee - Patent - New Act 11 2007-04-24 $250.00 2007-03-08
Maintenance Fee - Patent - New Act 12 2008-04-24 $250.00 2008-03-07
Maintenance Fee - Patent - New Act 13 2009-04-24 $250.00 2009-03-18
Maintenance Fee - Patent - New Act 14 2010-04-26 $250.00 2010-03-17
Maintenance Fee - Patent - New Act 15 2011-04-25 $450.00 2011-03-17
Maintenance Fee - Patent - New Act 16 2012-04-24 $450.00 2012-03-21
Maintenance Fee - Patent - New Act 17 2013-04-24 $450.00 2013-04-01
Registration of Documents $100.00 2014-02-06
Maintenance Fee - Patent - New Act 18 2014-04-24 $450.00 2014-04-07
Current owners on record shown in alphabetical order.
Current Owners on Record
HUNTLEIGH TECHNOLOGY LIMITED
Past owners on record shown in alphabetical order.
Past Owners on Record
HICKS, RONALD B.
KCI LICENSING, INC.
KINETIC CONCEPTS, INC.
LEININGER, PETER A.
VRZALIK, JOHN H.
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.

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Abstract 1997-09-29 1 59
Description 1997-09-29 20 962
Claims 1997-09-29 2 65
Drawings 1997-09-29 7 196
Cover Page 2005-06-17 1 39
Representative Drawing 1998-01-27 1 18
Description 2002-11-01 20 882
Drawings 2002-11-01 7 188
Claims 2003-07-14 2 75
Cover Page 1998-01-27 1 54
Claims 2004-02-23 2 68
Claims 2004-11-26 2 66
Representative Drawing 2005-02-09 1 9
Assignment 1998-09-23 7 286
Assignment 1997-09-29 2 91
PCT 1997-09-29 8 306
Correspondence 1997-12-09 1 29
Prosecution-Amendment 2002-05-01 4 180
Prosecution-Amendment 2002-11-01 20 778
Prosecution-Amendment 2003-01-15 4 203
Assignment 2003-07-07 4 139
Prosecution-Amendment 2003-07-14 7 361
Prosecution-Amendment 2003-08-21 3 118
Fees 1999-04-26 1 32
Fees 2001-04-10 1 43
Fees 2000-04-20 1 44
Fees 1998-03-17 1 37
Prosecution-Amendment 2004-02-23 8 350
Fees 2004-04-26 1 38
Prosecution-Amendment 2004-06-21 2 64
Prosecution-Amendment 2004-11-26 5 164
Correspondence 2005-04-26 1 32
Assignment 2014-02-06 59 3,714