U.S. patent application number 12/771189 was filed with the patent office on 2010-11-11 for internal structural configurations of bladders used in patient support systems.
This patent application is currently assigned to SPAN-AMERICA MEDICAL SYSTEMS, INC.. Invention is credited to James R. O'Reagan.
Application Number | 20100281618 12/771189 |
Document ID | / |
Family ID | 43061421 |
Filed Date | 2010-11-11 |
United States Patent
Application |
20100281618 |
Kind Code |
A1 |
O'Reagan; James R. |
November 11, 2010 |
INTERNAL STRUCTURAL CONFIGURATIONS OF BLADDERS USED IN PATIENT
SUPPORT SYSTEMS
Abstract
A bladder comprising an outer and inner surface having a length,
height and width, first and second ends, and an internal volume. A
support structure is disposed within the bladder and has a length,
width, height as well as an inner and outer region. The outer
region of the support structure comprises support projections which
define openings in the outer region of the support structure. The
support projections have an engaging end which contacts the inner
surface of the bladder and exerts force upon the inner surface of
the bladder. The support projections maintain the internal volume
of the bladder in a no-load sate. The openings in the support
structure allow air to move freely in the bladder versus a solid
support structure lacking openings. This aids in distribution of
air within the bladder and provides air-like pressure management
and comfort in addition to the structural support provided by foam
inserts.
Inventors: |
O'Reagan; James R.; (Greer,
SC) |
Correspondence
Address: |
DORITY & MANNING, P.A.
POST OFFICE BOX 1449
GREENVILLE
SC
29602-1449
US
|
Assignee: |
SPAN-AMERICA MEDICAL SYSTEMS,
INC.
Greenville
SC
|
Family ID: |
43061421 |
Appl. No.: |
12/771189 |
Filed: |
April 30, 2010 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61176555 |
May 8, 2009 |
|
|
|
Current U.S.
Class: |
5/709 |
Current CPC
Class: |
A61G 7/05769 20130101;
A61G 7/05715 20130101 |
Class at
Publication: |
5/709 |
International
Class: |
A47C 27/10 20060101
A47C027/10 |
Claims
1. A patient support system for the prevention and treatment of
decubitus ulcers, said patient support system comprising: a foam
shell defining an internal cavity; a plurality of air cells housed
in said internal cavity; and a cover encasing said foam shell;
wherein said plurality of air cells respectively each comprises a
bladder and an internal support structure comprised of resilient
material and only partly in contact with said bladder.
2. A patient support system as in claim 1, wherein: said bladder
comprises an outer and inner surface having a length, height and
width, first and second ends, and an internal volume; and said
support structure is disposed within said bladder and has a length,
width, height, and an inner and outer region.
3. A patient support system as in claim 2, wherein said outer
region includes support projections which define openings in said
outer region of said support structure.
4. A patient support system as in claim 3, wherein said support
projections each have an engaging end which contacts said inner
surface of said bladder and exerts force upon said inner surface of
said bladder, so as to maintain the internal volume of said bladder
whenever said patient support system is in a no-load sate.
5. A patient support system as in claim 2, wherein said support
structure comprises in a range generally from about 60% to about
90% of said bladder internal volume.
6. A patient support system as in claim 2, wherein said support
structure comprises one of a single piece or multi-piece construct
with support projections extending outwardly from said inner region
thereof.
7. A patient support system as in claim 2, wherein said support
structure extends one of the full length of said bladder or extends
only partially along the length of said bladder.
8. A patient support system as in claim 2, further including a
plurality of support structures enclosed within respective
bladders.
9. A patient support system as in claim 4, wherein: said support
projections extend radially outward from said inner region, spaced
either evenly or with varying spacing; and said engaging end of a
support projection comprises one of a point, a convex rounded
surface, a concave rounded surface, a flat surface, or combinations
thereof.
10. A patient support system as in claim 2, wherein each of said
bladders includes fluid comprising at least one of gas, liquids,
and relatively viscous liquids.
11. A patient support system as in claim 2, wherein said support
structure includes a cross-section which is one of star shaped, cog
or gear shaped, cross shaped, and convex shaped with truncated
projections.
12. A patient support system as set forth in claim 1, wherein: said
plurality of air cells are oriented from head-to-foot within said
foam shell; said cover includes a mattress topper; and said foam
shell is a multi-piece foam shell comprising foam bolsters, a foam
header and a foam footer.
13. A patient support system as set forth in claim 1, further
including an airflow unit for providing inflationary airflows to
said air cells.
14. A patient support system as set forth in claim 1, further
including a plurality of air tubes interconnected among said air
cells, for shifting air from cells under more pressure to cells
under less pressure, for equalizing pressure over the surface of a
patient received on said patient support system.
15. A patient support assembly, comprising: plural patient support
cylinders; a resilient foam perimeter surrounding said air
cylinders; an upper foam topper covering said air cylinders; and a
surrounding cover; wherein said cylinders respectively include
fluid and foam inserts having support projections supporting
associated of said cylinders; and said cylinders are positioned one
of generally longitudinally and generally laterally within said
resilient foam perimeter.
16. A patient support assembly as in claim 15, wherein: said
cylinders comprise static air cylinders; and said assembly further
includes pneumatic valving operatively interconnected to said air
cylinders for selectively introducing air and removing air
therefrom, so that said air cylinders may be selectively and
periodically recharged to a desired initial air pressure while
otherwise providing a static, unpowered assembly.
17. A patient support assembly as in claim 15, wherein said
cylinders comprise actively adjustable air cylinders.
18. A patient support assembly as in claim 15, wherein: said
cylinders respectively comprise bladders formed of resilient
material; and said support projections have an engaging end which
contacts the inner surface of said bladders and exerts force upon
said respective inner surfaces so as to maintain an internal volume
of said bladders in a no-load state.
19. A support system including a plurality of fluid receiving
cells, with each of said cells including at least one foam insert
having internal support structure only partly in contact with an
associated cell.
20. A support system as in claim 19, wherein: said support
structure comprises in a range generally from about 60% to about
90% of the interior of an associated cell; and said support
structure includes a cross-section which is one of star shaped, cog
or gear shaped, cross shaped, and convex shaped with truncated
projections.
21. A support system as in claim 19, wherein said fluid comprises
at least one of gas, liquids, and relatively viscous liquids.
22. A support system as in claim 19, further including: a foam
shell surrounding said plurality of fluid receiving cells; and a
cover encasing said foam shell; wherein said support system
comprises one of a mattress, a mattress overlay, an ergonomic
chair, a car seat, and a packaging arrangement for products.
Description
PRIORITY CLAIM
[0001] This application claims the benefit of previously filed U.S.
Provisional Patent Application entitled "Internal Structural
Configurations of Bladders Used in Patient Support Systems,"
assigned U.S. Ser. No. 61/176,555, filed May 8, 2009, and which is
incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
[0002] This subject matter generally relates to internal structural
configurations for bladders used in support surfaces for
preventing, reducing, and/or treating decubitus ulcers, also known
as pressure sores or bedsores.
BACKGROUND OF INVENTION
[0003] The present subject matter generally relates to bladders and
air cylinders used in patient support surfaces and more
particularly to combinations of foam and air or fluid technologies
which are selected so as to lend themselves to certain common
modular assembly features, in the context of improved performance
and/or costs.
[0004] Particularly in the field of healthcare, there has been a
long felt and profound need to provide pressure relief for immobile
or otherwise confined patients. For a tremendous variety of
reasons, many patients must withstand long periods of bed rest or
other forms of confinement, such as use of a wheelchair or other
accommodating but restrictive support arrangement. In those
instances, there is a tremendous risk that exposure to excess
pressure, or longer term exposure to relatively lower pressure
levels, can result in painful and even dangerous sores and other
conditions in addition to decreased oxygen uptake, loss of bone
mass, loss of skin integrity, loss of appetite, and decreased
cardiovascular functioning.
[0005] Literally an entire segment of the healthcare industry is
directed to the study and treatment of various tissue traumas, such
as decubitus ulcers. Tissue damage can be monitored and rated, with
progressively higher ratings warranting more involved treatment
approaches. For example, the Braden Scale is an assessment tool for
determining a patient's risk level for incurring skin breakdown.
Consequently, the healthcare industry perceives and evaluates
treatment options on the basis of their ability to address
conditions at such different stages or ratings.
[0006] Healthcare costs, generally, as well as patient well being
may be greatly affected by the degree of pressure relief for
patients confined to beds for significant periods of time. Pressure
sores (e.g. decubitus ulcers), potentially leading to infections
and other worsened conditions or complications can occur from
prolonged pressure exposure, such as experienced by those confined
to beds, whether in a hospital, nursing home, or private residence.
Considerable efforts have been made to provide mattress systems or
patient support surfaces which effectively redistribute and
equalize pressure forces at the interactions between the patient
and the support surface. Generally speaking, the more sophisticated
techniques for achieving such pressure reductions are relatively
more involved and therefore more expensive to manufacture and/or
use. Certain generally effective techniques involve the use of
elongated air tubes or cylinders variously combined with foam
pieces. Examples of embodiments having a plurality (such as four)
of generally longitudinal elongated air tubes are set forth in
commonly owned U.S. Pat. Nos. 5,070,560 and 5,412,821. Such patents
include the use of relatively stiffened lateral slats to help
convey and redistribute forces laterally from one air tube to
another. Such redistribution takes place over relatively limited
areas of contact between the respective elements. While such
approach is generally effective, one aspect of the present subject
matter seeks to improve on the redistribution and equalization of
pressure forces in the context of using such elongated air tubes
and to otherwise improve the function thereof.
[0007] Typically, various support systems have made use of
resilient support bodies, such as strips or blocks of foam, or some
other support bladder containing a specific fluid. Mattress
technologies, in general, have often made use of other resilient
support media, such as springs, slats, or various support fillers,
such as ticking. Different gases, often such as air, or various
liquids have been used, including relatively viscous liquids, such
as gels. In some instances, combinations of the above various
technologies have been used.
[0008] One aspect of support systems, especially concerning those
for use with recumbent patients, is that they are faced with
distinctly different loading requirements along the longitudinal
axis thereof. In other words, certain body areas of a patient will
be heavier than others, thereby generally requiring greater support
in such longitudinal areas if pressure relief is to be
optimized.
[0009] As a result, various support pads have sought to provide
sectionalized support. One such resilient foam pad making use of a
uniform patterned surface, though with differential resilient
support responsive to different loads, is U.S. Pat. No. 5,007,124
entitled "Support Pad with Uniform Patterned Surface."
[0010] As foam surface patterns become more sophisticated, there is
a corresponding increase in the difficulty of producing such
articles. One example of a three section foam mattress is U.S. Pat.
No. Des. D336,400, entitled "Foam Mattress Pad." Another example of
a still more complicated foam mattress surface, typically requiring
a computer controlled cutting machine for production, is U.S. Pat.
No. 4,862,538, entitled "Multi-Section Mattress Overlay for
Systemized Pressure Dispersion."
[0011] Still further examples of various resilient foam support
pads and the like, and certain aspects of manufacture thereof, are
shown by U.S. Pat. Nos. 4,603,445; 4,700,447; Des. D307,688; Des.
D307,689; Des. D307,690; 5,025,519; Des. D322,907; and 5,252,278.
Generally speaking, as support surface designs become more
entailed, they become more difficult and more expensive to produce.
At the same time, regardless of the manufacturing cost, they
provide a generally static or preset response to loading changes,
i.e., changes in the weight of the patient being supported in a
specific region of the pad. Such variations may occur due to the
variations among patients, or simply to the movement of an
individual patient.
[0012] One example of a pressure relief support system utilizing
fluid filled chambers is shown by U.S. Pat. No. 5,070,560, entitled
"Pressure Relief Support System for a Mattress." In such patent,
sealed longitudinal air cylinders are provided in the shape of a
mattress, otherwise having various transverse slats and/or foam
strips or members. Such a support system offers air dispersion
pressure treatment in a static design which avoids the relative
extremely high cost and other negative factors often associated
with active air bed systems.
[0013] Highest rated pressure relief support systems typically
involve beds having a plurality of fluid filled chambers, the
internal pressures of which are maintained at a constant pressure
by a relatively higher technology dynamic system approach.
Specifically, each fluid filled support element may be associated
with its own control valve, alternately permitting ingress and
egress of fluid. Various pressure sensitive detection devices
typically may be utilized in a feedback control system for
determining that an excess pressure condition (or a subpressure
condition) exists. Thereafter, the control technology is operative
for bleeding off excess pressure by selected valving operation
(such as dumping excess fluid into a reservoir arrangement) or for
actively pumping in additionally needed fluid.
[0014] As such, the above higher technology systems require various
motors, pumps, valving systems, sensory feedback arrangements, and
control systems for all the foregoing. Due to their complicated
construction and design, such beds are typically more expensive
with respect to initial purchase or rental cost. They can also be
complicated and expensive to maintain due to the prospect of
failure of numerous moving mechanical parts, and due to the
extensive training which an operator or maintenance person would be
required to undergo.
[0015] Also, there is the prospect of highly undesired heat
transfer to a patient, due to operation to the above-referenced
motors, pumps and other systems. Still further, the construction
and design of such overall systems often require specialized bed
frames not otherwise usable with typical mattresses.
[0016] Typically, air or fluid flows among the bladders disposed in
a patient support surface in response to the weight of the body to
equalize pressure throughout the system, provide a constant,
uniform distribution of safe pressures beneath the patient, and
prevent bottoming out of the support surface. The bladders are air
or liquid filled, as discussed above, or may be a bladder with a
foam insert such as those described by Giori et al. in U.S. Pat.
No. 6,922,863, Michiels in U.S. Pat. No. 4,407,031, Bondie et al.
in U.S. Pat. No. 6,588,038, Stinson et al. U.S. Pat. No. 5,388,292,
Stolpman et al. US RE38,135.
[0017] The existing bladders used in patient support platforms,
either air, liquid or air/liquid/foam filled, while providing a
surface for a patient, have various failings. Air or fluid filled
bladders achieve, through volume modulation, a very soft feel for
the user. However, air or liquid filled bladders are subject to
deflation if pierced while in use as well as "hammocking" or
"bottoming out" wherein the patient comes to rest on the substrate
beneath the bladder due to insufficient support. The problem with
pressurized air supported surfaces is that if air were allowed to
escape the pressurized chamber, the support surface would collapse
and cause a hammock effect.
[0018] Bladders that use foam inserts within an air filled bladder
fail to provide the measure of comfort associated with an air or
liquid filled mattress. Foam adjusts to the patient's body's
pressure points locally by the density of the foam increasing as
the foam is compressed by pressure from the patient's body.
Further, too soft of a foam can mimic the hammock or bottoming out
experienced with air or liquid filled bladders. Moreover, the foam
inserts impede the flow of air through the bladder, thus preventing
or significantly slowing the ability of the support surface to
adjust to the patient. Also, an undesirable characteristic of
open-cell flexible polyurethane foam is that it can potentially
solidify in a full vacuum-state, a so-called `compression set`
(CS). If too much air is removed from the cellular structure of
foam, it will harden in its densest state and subsequently no
longer be able to self-inflate and regain its loft, even partially.
CS becomes critical when foam has been compressed for an extended
period of time.
[0019] There exists a need for a simplified design for bladders or
air cylinders used in patient support systems which give the
clinician the needed options in addressing integrity of the skin
and deep tissues. A need exists to provide a bladder which is
simple to construct as well as providing a method of equalizing
pressure over the surface of the body by means of interconnected
air-filled tubes that shift air from tubes under more pressure to
tubes under less pressure. This allows greater immersion of the
body into the mattress, which decreases pressures under any single
point, and distributes pressures over as great an area as possible.
There also exists a need to combat the aforementioned failings
associated with air filled, liquid filled and air/liquid/foam
filled bladders by providing a bladder that combines the support
and comfort of an air or liquid mattress with the structural
support provided by a foam insert without diminishing the ability
of the patient support surface to rapidly adjust to pressure
changes.
[0020] The disclosure of all U.S. patents noted in this
application, above or hereinafter listed, are fully incorporated
herein by reference to the extent not inconsistent herewith.
SUMMARY OF THE INVENTION
[0021] The present subject matter recognizes and addresses various
of the foregoing problems, and others, concerning the bladders or
air cylinders present in patient support surfaces. Thus, broadly
speaking, a principal object of this subject matter is improved
patient support surfaces via improved bladders. More particularly,
a main concern is improved patient support surfaces of the type
involving bladders or air cylinders using combinations of foam and
air or liquid technology. Such patient support surfaces are
provided for receiving a patient thereon, and have at least one
adjustable fluid support bladder with fluid therein. Multiple fluid
support bladders may be used in additional embodiments and various
forms of foams and fluids may be practiced throughout all such
embodiments.
[0022] The present subject matter is directed to a bladder
comprising an outer surface, an inner surface, a length, a height,
a width, and first and second ends. The bladder has an internal
volume. There is a support structure disposed within the bladder
wherein the support structure comprises a length, a width, a
height, an inner region, and an outer region wherein the outer
region of the support structure comprises support projections which
define openings in the outer region of the support structure. The
support projections have an engaging end which contacts the inner
surface of the bladder and exerts force upon the inner surface of
the bladder to maintain the internal volume of the bladder in a
no-load state. A no-load state is the condition of the patient
support surface when a patient is not present on the surface.
[0023] In one exemplary embodiment, the support structure comprises
less than 90% of the internal volume of the bladder. In other
embodiments, it may comprise less than 80% whereas in further
embodiments it may comprise less than 70% or even less than 60%. In
one preferred embodiment, it may comprise about 80%. More broadly,
it is to be understood by those of ordinary skill in the art that
the present subject matter is intended as having a foam-to-air
ratio relatively as low as possible while still being able to have
the foam component to restore the unloaded volume of the tube. So,
for various embodiments depending on their specifics, it is
understood that such ratio will vary.
[0024] An exemplary support structure in accordance with the
present subject matter can be a single piece or multi-piece
construct with support projections extending outward from the inner
region. The support structure may extend the full length of the
bladder or extend only partially along the length of the bladder.
In another embodiment, there is more than one support structure
enclosed within the bladder. In still another present exemplary
embodiment, the inner region of the support structure defines a
cavity in the interior of the inner region. In still another
exemplary embodiment, the inner region of the support structure
defines more than one cavity in the inner region of the support
structure. The cavities can extend partially or entirely through
the length of the support structure.
[0025] With respect to the support projections, these may extend
radially outward from the inner region. In one embodiment, there
are at least three support projections extending from the inner
region. In other embodiments, more than three, such as four, fix or
six or more support projections extend from the inner region. In
accordance with the present subject matter, the spacing of the
support projections with respect to one another can vary. They may
be spaced evenly apart with respect to one another or they may be
randomly spaced with respect to one another.
[0026] In yet another embodiment, the bladder has support
projections comprised of a base which is integral with the inner
region of the support structure, a body which has a length and
extends away from the base, and the engaging end has a terminal
area which engages the inner surface of the bladder. In further
embodiments, the support projection may have a uniform width along
substantially all of its length. In other embodiments, the support
projection may taper along its length toward the terminal
point.
[0027] In another embodiment, the terminal area on a support
projection can be a point, a convex rounded surface, a concave
rounded surface, a flat surface, or combinations thereof. Moreover,
different support projections may have different terminal ends. For
example, in an embodiment with six support structures, three could
have terminal areas that are points, one a concave rounded surface
and two flat surfaces in order to aid with defining the structure
of the bladder.
[0028] In yet another embodiment, the bladder is in a patient
support surface and has an exterior, an interior, a length, a
height, a width and first and second ends. The bladder is flexible
and can expand and contract. There is a support enclosed within the
interior of the bladder. The support may comprise an inner core and
outer projections extending radially from the inner core. The outer
projections may define a space between each outer projection and
the next adjacent outer projection. The outer projections may each
have engaging ends which engage the interior of the bladder and
keep the bladder expanded by exerting an outward force when the
bladder is in a no load state.
[0029] In yet another embodiment, there is a modular patient
support assembly comprising plural patient support air cylinders.
The air cylinders comprise an outer surface, an inner surface, a
length, a height, a width, first and second ends. The air cylinders
have an internal volume. There is a support structure disposed
within the air cylinders wherein the support structure comprises a
length, a width, a height, an inner region, an outer region wherein
the outer region comprises support projections which define
openings in the outer region of the support structure. The support
projections have an engaging end which contacts the inner surface
of the air cylinders and exerts force upon the inner surface of the
air cylinders and maintain the internal volume of the air cylinders
in a no-load state. There may be a resilient foam perimeter
surrounding said air cylinders and supplemental inner bolsters
provided within an inside perimeter defined by said resilient foam
perimeter. There is also an upper foam topper covering said air
cylinders and including underside multiple curved projections
interoperative with said air cylinders for positional stabilizing.
A surrounding cover may also be utilized.
[0030] Another present general object is to provide a fully
self-adjusting pressure relief system which optimizes pressure
dispersion, while still using a relatively inexpensive and simple
designs so as to obviate the need for motors, control systems, or
specialized bed frames or training associated with its use and,
maintenance.
[0031] Yet another object is to provide a pressure relief support
system which is self-adjusting to allow for more even body weight
distribution, thereby improving the reduction of pressure on the
tissue and skin of a user. At the same time, it is an object to
provide a self-adjusting technology which may be customized, as
desired, for different patient uses, and for different alternate
uses.
[0032] More specifically, it is a present object to provide a
self-adjusting pressure relief technology which is usable with
virtually any type of fluid (gas, liquid, relatively viscous
liquids), and which is usable in a variety of settings.
Specifically, it is intended to provide such self-adjusting
technology usable in both medical and commercial fields, including
both mattress-related technologies and seating technologies, as
well as others. In the area of medical uses, it is intended to
provide a system and improved technology which is usable in space
critical circumstances, such as involving X-ray, operating room, or
NMR technology uses. It is intended for the present technology to
be equally applicable to critical care situations, emergency room
gurneys, ambulance stretchers, and medical seating systems of all
types, such as wheelchairs or geriatric chairs.
[0033] It is another present object to provide a self-adjusting
technology with the advantages of active (i.e., dynamic)
fluid-based systems, but with such simplicity that the technology
may be extended to every day consumer products, such as ergonomic
chairs and car seats, as well as consumer mattress replacement
systems, mattresses and mattress overlays (as would also be
applicable in the medical field).
[0034] It is a still further object of the present subject matter
to provide a technology capable of being customized to provide
specialized support surfaces, such as for pregnant women, or for
amputees or other persons requiring nonconventional support needs
for either sitting or sleeping or bed rest.
[0035] Still further, it is a present object to provide improved
technology applicable in a broad sense virtually to any
circumstance of bodies in rest. For example, such technology may be
incorporated into specialized pillows, such as in the case of head
injuries involving swelling or other weight changes. Likewise, the
present technology would be equally applicable to packaging
arrangements (such as for fragile equipment) where it is desired to
minimize or limit pressures associated with transfer shock or the
like.
[0036] One present exemplary embodiment relates to a patient
support system for the prevention and treatment of decubitus
ulcers. Such an exemplary patient support system may preferably
comprise a foam shell defining an internal cavity; a plurality of
air cells housed in such internal cavity; and a cover encasing such
foam shell. With such exemplary arrangement, preferably such
plurality of air cells respectively each comprises a bladder and an
internal support structure comprised of resilient material and only
partly in contact with such bladder.
[0037] Another present exemplary embodiment may relate to a patient
support assembly, comprising plural patient support cylinders; a
resilient foam perimeter surrounding such air cylinders; an upper
foam topper covering such air cylinders; and a surrounding cover.
Preferably, in such exemplary arrangement, such cylinders
respectively include fluid and foam inserts having support
projections supporting associated of such cylinders; and such
cylinders are positioned one of generally longitudinally and
generally laterally within such resilient foam perimeter.
[0038] In yet another present exemplary embodiment of the present
subject matter, a support system may preferably include a plurality
of fluid receiving cells, with each of such cells including at
least one foam insert having internal support structure only partly
in contact with an associated cell.
[0039] Additional objects and advantages of the present subject
matter are set forth in or will be apparent to those of ordinary
skill in the art from the detailed description which follows. Also,
it should be further appreciated that modifications and variations
to the specifically illustrated and discussed features, steps or
materials hereof may be practiced in various embodiments and uses
of this subject matter without departing from the spirit and scope
thereof, by virtue of present reference thereto. Such variations
may include, but are not limited to, substitution of equivalent
means and features, materials or steps for those shown or
discussed, and the functional or positional reversal of various
parts, features, steps, or the like.
[0040] Still further, it is to be understood that different
embodiments, as well as different presently preferred embodiments,
of this subject matter may include various combinations or
configurations of presently disclosed features, steps, or elements,
or their equivalents (including combinations of features or steps
or configurations thereof not expressly shown in the Figures or
stated in the detailed description). Also, it is to be understood
that various features from one embodiment; as illustrated,
discussed or suggested, may be combined with or substituted for
features of other disclosed or suggested embodiments, within the
spirit and scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] A full and enabling disclosure of the present subject
matter, including the best mode thereof, directed to one of
ordinary skill in the art, is set forth in the specification, which
makes reference to the appended Figures, in which:
[0042] FIG. 1 is an exploded view of a prior art device wherein
representative bladders are shown in relation to other elements,
collectively comprising a patient support surface;
[0043] FIG. 2 is a perspective view of a prior art device wherein
representative bladders are shown in relation to other elements,
collectively comprising a patient support surface;
[0044] FIG. 3A is a top plan view of a prior art device wherein
representative bladders are disposed parallel to the user's body in
a patient support surface;
[0045] FIG. 3B is a top plan view of a prior art device wherein
representative bladders are disposed perpendicular to the user's
body in a patient support surface;
[0046] FIG. 4 is a perspective view of one exemplary embodiment of
the present subject matter, showing exemplary support structure and
an enclosing bladder;
[0047] FIG. 5A is a perspective view of one embodiment of the
present subject matter illustrating an exemplary support structure
without an enclosing bladder;
[0048] FIG. 5B is a perspective view of another embodiment of the
present subject matter, showing an alternative exemplary support
structure without an enclosing bladder, where such exemplary
support structure has a four point star cross-sectional
configuration;
[0049] FIG. 5C is a perspective view of yet another embodiment of
the present subject matter showing an alternative exemplary support
structure without a bladder, where such exemplary support structure
has a cog or gear-shaped cross-sectional configuration;
[0050] FIG. 5D is a perspective view of a further embodiment of the
present subject matter showing an alternative exemplary support
structure without a bladder, where such exemplary support structure
has a cross-shaped cross-sectional configuration;
[0051] FIG. 6 is an end elevation view of one end of the exemplary
support structure and bladder as shown in present FIG. 4, and
illustrating engagement of such exemplary support structure with
the interior of such exemplary bladder;
[0052] FIG. 7A is an end elevation view of one end of an
alternative embodiment of the support structure and bladder as
generally shown in present FIG. 4, wherein such exemplary support
structure has support projections with convex shaped engaging ends,
based on truncated projections; and
[0053] FIG. 6B is an end elevation view of one end of a further
alternative embodiment of the support structure and bladder
generally as shown in present FIG. 4, wherein such exemplary
support structure has a five pointed star shaped support structure
with pointed engaging ends.
[0054] Repeat use of reference characters throughout the present
specification and appended drawings is intended to represent same
or analogous features, elements, or steps of the present subject
matter.
[0055] It is to be understood that the present language is by way
of example and description only and is not intended to limit the
broader scope of the present subject matter as otherwise disclosed
herewith, including features as referenced in the Figures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0056] Reference will now be made in detail to presently preferred
embodiments of the present subject matter, examples of which are
discussed in conjunction with the accompanying drawings. Such
examples are provided by way of an explanation of the present
subject matter, not limitation thereof. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present subject matter, without
departing from the spirit and scope thereof. For instance, features
illustrated or described as part of one embodiment can be used on
or in another embodiment to yield a still further embodiment. Still
further, variations in selection of materials and/or
characteristics may be practiced, to satisfy particular desired
user criteria. Thus, it is intended that the present subject matter
cover such modifications and variations as come within the scope of
the present features and their equivalents.
[0057] Particularized definitions used herewith include:
ILD--Indentation Load Deflection or IFD--Indentation Force
Deflection--measure of the stiffness of open-cell foam which
measures conformability or ability to immerse the patient to
distribute weight as well as measures the compressibility or the
ability to support the patient and prevent bottoming out. Measured
as the number of pounds needed to indent a
4''.times.12''.times.12'' sample of the foam with a 50 square inch
circular plate a certain distance. 25% ILD/IFD--indents the foam
25% of the way through the sample, or 1''. 65% ILD/IFD--indents the
foam 65% of the way through the sample, or 2.5''. No-Load
State--the condition of the patient support surface when a patient
is not present on the surface.
[0058] While in accordance with the present subject matter no
particular measurements are contemplated as necessary or required
with respect to the outward forced applied by the support
projections on the inner surface of the bladder, the present
subject matter does consider the "preload" on the star (or other
design) tips based on the amount of interference between the tube
diameter and the star "diameter". For example, the present subject
matter may encompass a range of designs, from the radius of the
star being 10% larger than the radius of the tube to the radius of
the star being 20% smaller than the radius of the tube, or even
designs outside of such range. In general, those of ordinary skill
in the art will appreciate that one of the trade-offs to be
considered in any given embodiment is the level of functionality
desired versus the desired cost of manufacturing for a particular
foam-in-tube design, all of which variations are intended as being
encompassed by the present disclosure.
[0059] Applicant hereby incorporates by reference, in their
entirety, U.S. Pat. Nos. 6,782,574 and 6,223,369, to the extent not
inconsistent herewith.
[0060] FIG. 1 is an exploded generally top and mostly end
perspective view of a prior art patient support surface wherein a
plurality of generally longitudinally-place bladders 100 are shown
in relation to other elements comprising a patient support surface.
U.S. Pat. Nos. 6,223,369 and 6,782,574 disclose a patient support
surface into which presently disclosed bladders could be
incorporated and are hereby incorporated fully by reference.
Patient support surface 34 includes a foam topper 24 which may be
integrally included within the patient support surface.
Particularly, the upper support surface of such foam topper may
include a variety of constructions designed and intended to
facilitate pressure relief. Pressure relief, for example, may be
provided by a number of lateral cuts or channels generally 26
formed in such surface as illustrated in solid line. Another aspect
of the patient support surface is a pair of inner bolsters 68 and
70, which run longitudinally along the lengthwise axis of patient
support surface 34. As illustrated, each inner bolster 68 and 70
has a respectively inwardly facing concave surface 72 and 74 which
interacts with part of the curvature of respective air bladders
200. Still further, each concave face 72 and 74 is provided with at
least one respective curved slot 76 and 78, respectively, therein,
for purposes as further discussed below.
[0061] Patient support surface 34 also includes perimeter bolster
components 16 and 18. These may be of relatively more dense
material for relatively greater support than side or inner bolsters
68 and 70, which in turn may be of relatively greater density or
firmer support than foam topper 24. As shown, a plurality of
depending elements 82, 84, and 86 constitute projections which
approximate inverted contoured triangles. Otherwise formed in the
underside surface 80 of foam topper 24 are a plurality of
downwardly facing arches generally 88, 90, 92, and 94. As will be
understood by those of ordinary skill in the art, such respective
arches run along the longitudinal length of foam topper 24 formed
in the underneath side 80 thereof. Likewise, the underside arches
interact and interface with the generally top sides of the
respective bladders 100, such that the depending elements 82, 84,
and 86 work into the areas between the respective bladders 100. The
resulting combination cradles and surrounds the bladders, providing
an interlocked, integrated design having flexible, progressive
support while maximizing structural integrity. Such integrated
structural integrity includes the beneficial tube capturing effects
of the side or inner bolsters 68 and 70, as well as the beneficial
effects of perimeter bolster 14 as shown by present FIG. 2.
[0062] FIG. 2 is a generally top and partial side perspective view,
in partial cutaway, of a prior art patient support surface.
[0063] FIGS. 3A and 3B are respective top plan views of prior art
devices, representing bladders 100 can be disposed parallel to the
user's body in a patient support surface 34, or with bladders
generally 102 disposed perpendicularly to the user's body.
[0064] It is to be understood that any of the various exemplary
support structure and enclosing bladders disclosed herewith per
present subject matter may be variously incorporated in place of
bladders 100 and/or 102 of the foregoing exemplary patient support
surfaces. Likewise, present exemplary support structure and
enclosing bladders may be utilized in conjunction with other forms
of patient support surfaces, or in other entire arrangements.
[0065] FIG. 4 is a perspective view of one embodiment of the
present subject matter showing an exemplary support structure 216
and a representative enclosing bladder 200. It is to be understood
that the various exemplary support structures of the present
subject matter may be utilized in conjunction with such enclosing
bladders, as desired for different present embodiments, all of
which in turn may be used in the representative patient support
surfaces described herein, or in other combinations.
[0066] The exemplary support structure generally 216 of present
FIG. 4 can be formed from any suitable composition including foam,
plastic, meltblown or spunblown materials or other suitable
structural materials known to those skilled in the art. One
presently preferred example may be polyurethane foam or even a
combination of different density/ILD polyurethane foams that are
laminated together. For example, one may use HR11 Ca Dark Green
polyurethane made by NCFI, 2#/ft3, 13 ILD Ca117. Other non-limiting
examples may include the following, selected also in conjunction
with the turn angle when needed and the desired level of comfort.
Several of the more important properties are stated below in
density and ILD, for three different examples regarding three
different kinds of foam for the Star Chamber air cylinders:
TABLE-US-00001 Exemplary Foam Density ILD HR11 Ca Dark 2.0 pounds
per cubic foot 13 pounds Green PRS35 Ca Tan 2.25 pounds per cubic
foot 35 pounds UC11 1.5 pounds per cubic foot 14 pounds
[0067] Examples of particularly suitable foams include
polyethylene, polyurethane, polyester, straight chain or
cross-linked varieties of each as well as combinations of
polyethylene, polyurethane, and polyester foams. Preferably the
foam will have a density range of about 1.5 to about 2.5
lbs/ft.sup.3 and an IFD/ILD range of about 12 to about 15. The foam
can be either an open cell or a closed cell type foam. With an open
cell foam, air flows through the foam cells as the air travels from
one chamber to another. With a closed cell foam, air on the surface
of the foam is allowed to flow between the foam and bladder 200.
Upon impact or load, the air contained within the closed cells is
also compressed.
[0068] The exemplary support structure 216 comprises a length 218,
a width 220, a height 222 and has a volume and can assume any shape
known to those skilled in the art. Particularly preferable shapes
include those comprising projections extending from a central core
or central region such as a star or gear shape. Support structure
216 also comprises support structure first face 224 and support
structure second face 226. The foam can have either an open or a
closed cell structure. In one preferred embodiment, an open cell
structure is used. As shown by respective FIGS. 5A-5D, exemplary
alternative shapes respectively 217, 219, 221, and 223 of the
support structure 216 are envisioned.
[0069] As shown by FIG. 6, the exemplary support structure 216 also
comprises an inner region generally 228 with support projections
230 extending outwardly from inner region 228. Such support
projections 230 preferably define openings generally 232. Openings
232 are unbounded by the support structure 216 in at least one
direction. For purposes of example only, when the openings 232 are
in the shape of a triangle, the base of the triangle (which would
face toward the inner surface of the bladder 200) is open and not
enclosed by the support structure 216, while the sides of the
triangle are otherwise enclosed by the support structure 216.
[0070] The support projections 230 and openings 232 comprise outer
region generally 234, which is the region of the bladder comprised
of the support projections 230 and the openings 232 they
define.
[0071] Openings 232 can extend the length of the support structure
216. Each opening 232 is defined by two support projections 230. In
an alternative embodiment, openings 232 may only extend partially
through a present support structure, such as structure 216 (or any
other present embodiments). In a further embodiment, openings 232
may originate at both support structure first end 224 and support
structure second end 226, and may be offset with respect to one
another as the openings 232 extend the length of the support
structure 216.
[0072] Support projections 230 have an engaging end 236 located
away from the inner region 228 which comprises the portion of the
support structure 216 not including the support projections 230 and
the openings 232 they define.
[0073] In a further embodiment, inner region 228 may define a
cavity 238 which can extend throughout the length of support
structure 216. Alternatively, cavity 238 may only extend partially
along the length of support structure 216. Cavity 238 may be any
shape known to those of skill in the art but is representatively
illustrated in FIG. 6 as a circle for illustrative purposes only.
In a further embodiment, cavity 238 may be present on support
structure first face 224 and support structure second face 226,
present on one or the other or present on neither yet contained
within support structure 216 in a "hollow" configuration.
[0074] Support projections 230 also have a support projection base
240 as illustrated by the dashed line PB on FIG. 6 and a support
structure body length 241 illustrated by dashed line BL on FIG. 6.
In a preferred embodiment, support projections 230 are integral
with support structure inner region 228. Support projections 230
also have a support projection body 242 which extends generally
away from inner region 228. Support projection body 242 ends with
terminal area 244. Terminal area 244 may comprise a point, a convex
rounded surface, a concave rounded surface, a flat surface or
combinations thereof, or other. For example, in one embodiment
wherein support structure 216 comprises five support projections,
two may have a terminal area 244 that is a point, one terminal area
may be a convex rounded surface, and two terminal areas may be a
flat surface.
[0075] As shown by FIG. 4, the bladder 200 encloses the support
structure 216. The bladder 200 can be made of any suitable material
known in the art including but not limited to plastic, polymers,
meltblown or spunblown material, cloth, rubber, or coated fabrics.
One exemplary embodiment of bladder material may comprise Stevens
polyurethane film; ST 2592. Others may so involve, for example,
ST3380 and ST3382, all of which have various lists of different
characteristic (for example, durometer, permeability, melt point,
etc) which may variously be considered by those of ordinary skill
in the art whenever implementing particular embodiments in
accordance with the present subject matter. Similarly, various
thicknesses may be practiced in accordance with the present subject
matter, with some preferred examples falling into a range of about
12 mils to about 15 mils. Urethane coated nylon is among some of
the preferred embodiment materials while urethane is preferred in
some instances because it inherently permits viewing of the
star-shaped insert (or other internal component) upon inspection,
while urethane coated nylon would not provide such feature. The
bladder 200 comprises an outer surface 202, an inner surface 204, a
length 206, a height 208, a width 210, and a first end 212 and a
second end 214. The bladder 200 may be opaque or clear. In certain
embodiments, the bladder 200 has a column shape but may also have a
cigar shape, rectangular, or other shape known to those skilled in
the art. It is understood that the volume of the bladder 200 will
be calculated based on the shape of the particular embodiment being
measured as known to those skilled in the art. For purposes of
example only, in instances where the shape is columnar, volume will
be calculated as pi multiplied by the radius squared multiplied by
the length of the column. In rectangular or square embodiments,
volume is calculated as length multiplied by width multiplied by
height. It is further understood that in some embodiments bladder
height and width may be equal or they may be different, e.g., in
ellipsoid shaped bladders. Bladder 200 is intended as representing
all such variations of the present subject matter.
[0076] In one present exemplary embodiment, the support structure
first face 224 contacts bladder first end 212, and support
structure second face 226 contacts bladder second end 214. In other
embodiments, support structure first face 224 and second face 226
do not contact bladder first end 212 and bladder second end 214. In
still another embodiments, support structure first face 224 or
second face 226, or both, may comprise support projections 230
which extend outward from each face to engage bladder first end 212
and bladder second end 214, respectively. Either first end 212 or
second end 214 may have a connection (not shown) as known to those
skilled in the art made with a respective section of tubing (not
shown). Such air tubing interconnects with the interior of the
bladder to facilitate initially establishing air pressure therein
and/or later adjusting such amount of air pressure.
[0077] Alternatively, bladder 200 may be arranged in series with
other bladders with interconnections between bladders 200 to allow
air or fluid to pass from one bladder 200 to another in response to
pressure applied to the patient support surface. In addition to the
numerous support arrangement variations which may be practiced,
including longitudinal, lateral, angular, and mixed arrangements of
single or multiple air or fluid bladders 200, in accordance with
the present subject matter, it is also to be understood that
numerous self-adjusting components may be provided in accordance
with the present subject matter for use with various such support
arrangements. Further, when bladder 200 is used in series with
other bladders 200, it is understood that the plurality of bladders
200 are arranged so that preferably they do not contact one another
during various loading conditions, though contact may be involved
in some instances, when the patient support surface or other
embodiment is either loaded or unloaded.
[0078] In one present exemplary embodiment, the volume of support
structure 216 may comprise substantially all of the volume of
bladder 200. In another embodiment, support structure 216 may
comprise 90% or less of the volume of bladder 200. In other
embodiments, support structure 216 may comprise 80% or less of the
volume of bladder 200, 70% or less or even 60% or less of the
volume of bladder 200. In one preferred embodiment, it may comprise
about 80%. More broadly, as otherwise discussed herein, it is to be
understood by those of ordinary skill in the art that the present
subject matter is intended as having a foam-to-air ratio relatively
as low as possible while still being able to have the foam
component to restore the unloaded volume of the tube, which results
in varying ratios for particular embodiments depending on their
specifics.
[0079] The various embodiments of the present subject matter
disclosed herein are used to assist with increasing comfort and
stability in patient support surfaces using a combination air or
fluid filled bladder 200 and internal support structure 216. The
present subject matter can be used in conjunction with a method of
equalizing pressure over the surface of the body by means of
interconnected air or fluid-filled tubes that shift air or fluid
from bladders under more pressure to bladders under less pressure.
Such functionality allows greater immersion of the body into the
mattress, which decreases pressure under any single point, and
distributes pressure over as great an area as possible.
[0080] The present subject matter allows the support structure 216
to keep the bladder 200 expanded by the support projections 230
contacting the inner surface 204 of the support bladder 200 via
terminal area 244. Bladder 200 thus exerts force upon inner surface
204. Accordingly, bladder 200 does not collapse if air pressure in
the bladder 200 is reduced. Further, using support structure 216
which contains support structure openings 232, which are defined on
either side by support projections 230, one is able to use less
foam in constructing the support structure 216 via incorporation of
support structure openings 232.
[0081] Further, support structure openings 232 in support structure
216 provide several distinct advantages over existing systems. Such
advantages may include allowing bladder 200 (which in one exemplary
embodiment may be an air filled bladder containing foam support
structure 216) to possess the feel and support of an air mattress
as known to those skilled in the art while also maintaining the
benefits of a foam mattress. Such advantageous performance includes
increased structural support as well as protection against the
bladder 200 collapsing when air pressure is removed or if the
bladder 200 is punctured. Additional advantages include that
openings 232 serve to allow air or fluid to move more freely within
the bladder 200 as opposed to existing systems where the foam block
is a solid construct that essentially fills the interior of the air
cylinder used in such devices. In the present subject matter,
openings 232, or in alternative embodiments cavity 238 alone or in
combination with openings 232, allow air or fluid to move about in
the bladder 200 with less restriction.
[0082] Air or fluid can move within openings 232 or cavity 238
without necessitating air or fluid flow through the material
comprising support structure 216. Such advantageous functionality
prevents slowing air or fluid movement which in turn slows the
ability of the bladder 200 to react to patient movement or pressure
changes.
[0083] Embodiments of the present subject matter also help overcome
the tendency of existing patient support systems toward
"hammocking" wherein pressure accumulates toward the area of least
lateral support, often the center of a patient support surface.
This results in a hammock effect, which is uncomfortable for a
person resting on the mattress. Moreover, when air is let out of
existing patient support systems incorporating only air-filled
bladders, the entire apparatus collapses and no longer supports the
reclining body, the hammock effect being present all the way down
through partial deflation. Such characteristic can be undesirable
in a mattress because each movement of weight, such as found in a
typical person's sleeping pattern, shifts the hammock effect around
on the mattress.
[0084] Use of the present subject matter would be applicable to all
manner of seating arrangements (including partially reclined or
angled seating arrangements such as military vehicles designed to
withstand acceleration shock). Applicable seating arrangements may
include wheelchairs and geriatric care chairs of all type. Consumer
seating arrangements may also include ergonomic chairs (such as for
office workers) and automobile or transportation vehicle seating
devices of all types. In conjunction with such, there could be a
particular improvement in rider comfort, especially in long term
travel circumstances or otherwise rough ride circumstances such as
in trucks or trains.
[0085] It will likewise be understood that multiple bladders 200 in
accordance with the present subject matter may be so arranged
(i.e., combined), as desired, in either seating arrangements or
mattress or patient support systems of virtually all types. In
conjunction with medical products, such specialized mattresses may
include mattresses themselves, or mattress overlays, or mattress
replacement systems. The resulting support systems may be
specialized for X-ray, operating room, or NMR/MRI technology use.
Still further, arrangements thereof may be made for intended use in
either intensive care or regular care settings, including home
healthcare or nursing home settings. The present subject matter
would likewise be applicable to all manner of critical care
settings, as well as burn patient settings, emergency room gurneys,
and ambulance stretchers.
[0086] In addition to the many embodiments referenced above, it is
to be further understood that other variations may be practiced so
as to combine different features for obtaining bladders for use in
patient support surfaces and other supports of types not
illustrated. For example, a bladder in accordance with present
subject matter can be created with uses a low molecular weight
liquid in association with multiple support structures disposed in
a bladder. Further yet, the number and method of orienting the
bladders may be changed, such as placing bladders alongside and on
top of one another for use in a patient support surface. All such
variations and modifications are intended to come within the spirit
and scope of the present subject matter. Therefore, the spirit and
scope of the present subject matter should not be limited to the
description of the exemplary presently preferred versions contained
herein.
* * * * *