Note: Descriptions are shown in the official language in which they were submitted.
CA 02593342 2007-07-26
PATIENT SUPPORT SURFACES
This application is a division of Canadian patent
application serial No. 2,309,751 filed 13 November 1998 as the
Canadian national phase application corresponding to
International application No. PCT/US98/24310 filed 13 November
1998.
BACKGROUND OF THE INVENTION
.The present.invention relates generally to improved patient
support surfaces and more particularly to combinations of foam
and air technologies which are selected so as to lend themselves
to certain common modular assembly features, in the context of
improved performance and/or costs.
Healthcare costs generally as well as patient well being
may be greatly effected by the degree of pressure relief for
patients confined to beds for significant periods of time.
Pressure sores (eg. 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 epeaking, the more sophisticated techniques for
achieving such p'ressure reductions are relatively more involved
and therefore more expensive to manufacture and/or use.
Examples of embodiments having four generally longitudinally
elongated air tubes are set forth in commonly owned U.S. Patent
No. 5,070,560 issued on December 10, 1991, and U.S. Patent No.
5,412,821 issued on May 9, 1995. Such patents include the use
of relatively stiffened lateral slats to help convey
CA 02593342 2007-07-26
2
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 invention seeks
to improve on the redistributiqn and equalization of
pressure forces in the context of using such elongated
air tubes and to otherwise improve the function
thereof.
Another aspect of patient support surfaces
generally relates to patient safety.., Specifically,
through either voluntary or involuntary movement (such
as during sleep), patients may tend to move around on
a support surface, includimg movement towards the edge
of such surface. Many bed~ systems have .large metal
rails or other similar devices to- help prevent
accidental injury in the event that a patient
inadvertently rolls off of the patient support
surface.= Such barriers or other buildups may prove
awkward and obstructive whenever it is otherwise
desired to assist a patient with entry to or egress
from a bed.
Another aspect of patient safe interaction involves
a potential tendency for some air mattress systems to
"roll" or boost a patient forward as they are seated
on the edge of a support surface. Such situation
could cause a patient to tend to lose balance if they
egress from a bed unassisted. Again, obstructions or
buildups put in place to help prevent such occurrences
otherwise interfere with desired patient transfers or
edge-of-bed sitting.
Still another particular aspect of patient support
surfaces relates to the relatively high degree of
pressure forces which are placed on the heels of a
patient. The relatively excessive pressures focused
CA 02593342 2007-07-26
3
on the heels are often difficult forces to be
effectively accommodated by many existing patient
support systems. Such is particularly true where a
system seeks to address* total comfort from a balanced
perspective, as opposed to focusing on heel pressure
reduction. Hence, excessive or undesired heel
pressure levels remain, resulting in patient
discomfort and/or negative health consequences.
Another general limitation of static non-powered
air tube technology relates to potential tube air
loss. Ordinarily, there are no mechanisms for
compensating for any air losses or other causes of
pressure/inflation changes from the original
specifications established/by the manufacturer.
$VNIIMARY OF THE IPiVENTION
The present invention recognizes and addresses
various of the foregoing problems, and others,
concerning patient support surfaces. Thus, broadly
speaking, a principal object of this invention is
improved patient support surfaces. More particularly,
a main concern is improved patient support surfaces of
the type involving combinations of foam and air
technology. It is therefore another particular object of the
present invention to provide an overall construction
for a grouping of different patient support surfaces
involving combinations of foam and air technology
which are facilitated by modular assembly components.
It is another general object of the present
invention to provide perimeter foam construction
techniques which cooperate with improved tube/foam
CA 02593342 2007-07-26
4
interface components to collectively improve combined
foam and air technology construction for both improved
comfort and maximized structural integrity.
Another general object of the present invention is
to provide improved patient support surfaces with
reference to patient safety. More specifically, it is
an object to facilitate safer transfers and more
stable edge-of-bed sitting. Iii such context, it is an
object to provide patient support surfaces which
gently prompt a patient towards the center of the bed
without requiring awkward buildups o:r structures which
would otherwise obstruct entry to or egress from such
patient support surfaces. -
Still a further more paiticular object of the
present invention is to provide inner bolster and foam
topper constructions which work in concert with
integrated air tubes or cylinders. More specifically,
it is an object to provide interlocking, integrated
designs-which provide flexible, progressive support
while maximizing structural integrity of the overall
.patient support surface.
It is another object to provide improved heel
comfort by redistributing and equalizing loads to more
relatively pressure-tolerant lower legs and calves.
It is a particular object to achieve such improved
heel comfort and improved patient health by providing
particular sloping heel pressure relief sections
incorporated into various embodiments of foam mattress
toppers integrally built into different embodiments of
patient support surfaces in accordance with this
invention.
Yet another present object is to provide an
embodiment of static non-powered patient support
surface which is nonetheless able to be "recharged" in
the field. In other words, it is an object to achieve
CA 02593342 2007-07-26
s recalibration of etatic air cylinders in the field at
various periodic"intervals of use (such as a certain
number of months), to return their inflation
specifications to the original manufacturer specs.
It is anothtr,object to provide a modular assembly
chassis which may be used in common with a number of
different embodiments of patient support surfaces
(such as involving progressively.sophisticated
technologies) for creating a line of surface products
based on the efficiency of common features. In such
context, it is an object to formulate constructions
which inherently provide improved patient protection
against unintended rolling near the edge of the
patient support surface or/unintended forward pitching
from the edge of the support surface during entry
thereto or egress therefrom.
Additional objects and advantages of the invention
are set forth in, or will be apparent to those of
ordinary pkill in the art from, the detailed
description herein. Also, it should be further
appreciated that modifications and variations to the
specifically illustrated and discussed features and
steps or materials and devices hereof may be practiced
in various embodiments and uses of this invention
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.
Still further, it is to be understood that
different embodiments, as well as different presently
preferred embodiments, of this invention may include
various combinations or configurations of presently
CA 02593342 2007-07-26
. . . ' .. ., '
6 =
disclosed features, elements, or steps, or theit
equivalents (including combinatione of features or
steps or configurations thereof not expreeely shown in
the figures or stated in the detailed deecription).
One exemplary embodiment of the present invention
relates to improved patient support surfaces having
perimeter bolster features which facilitate structural
integrity and patient protectiQn. Other present
exemplary embodiments include combinations of inner
bolster features and foam toppers with underside
features for engaging and capturing prepositioned
longitudinal and/or lateral placed aircylinders, for
improved patient support surface integrity and
performance. ~
Yet other exemplary constructions comprising
present exemplary embodiments include foam toppers
which have integrally incorporated therawith a sloping
heel preesure relief section for improved'patient heel
health.
Still further, other present exemplary embodiments
include various combinations of the foregoing features
so as to result in a modular assembly common to
different embodiments of static or dynamic and/or non-
powered or powered patient support surface
constructions.
.Still further exemplary embodiments relate to the
methodology involved with such exemplary foregoing
mattress embodiments which comprise static non-powered
air cylinder configurations. More particularly, such
methodology relates to the ready ability to recharge
such static air cylinders "in the field" (such as at a
hospital or nursing home facility or even at a private
residence) so as to reestablish the original
manufacturer's inflation specifications.
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'
Those of ordinary skill in the art will better
appreciate the features and aspects of such
embodiments and methodologies, and others, upon review
of the remainder of the specification.
BRlalr DEBciRIpTION OF TSls DR]1WIN(~S
A full and enabling disclosiire of the present
invention, =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:
Figure 1 is a generally top and pgrtial side
perspective view, in partial cutaway, of a patient
support surface in accordan~ce with the present
invention, and primarily illustrating certain modular
.aseembly aspects thereof;
Figure 2 is an exploded generally top and mostly
end perspective view of a portion of a firat
embodiment of,the subject invention (with an outer
cover thereof removed), primarily relating to a
rechargeable static, non-powered patient support
surface;
Figure 3A.is a cross sectional representation,
taken generally along';,the position of the section line
3A-3A of present Figure 2 (otherwise shown in an
exploded view) as such embodiment in part would appear
in assembled form;
Figure 3B is an enlarged partial view of the cross
section of present Figure 3A, shown=during exemplary
reaction of such arrangement during patient use
thereof, for improved controlled entry to or egress
from the exemplary patient support surface;
Figure 4 is an enlarged partial perspective view of
an external segment of the embodiment of Figure 2,
represented during practice of the present methodology
CA 02593342 2007-07-26
s '
for recharging such static, non-powered patient
support surface embodiment of present Figure 2;
Figure 5-is an isolated, enlarged side elevational
view of sloping heel pressure relief section features
which may be integrally incorporated into foam topper
components in accordance with the subject,invention;
Figure 6 is an exploded generally top=and mostly
end perspective view similar to that of present Figure
2 (and aleo with an outer cover thereof removed), but
representative of a portion of a dynamic, non-powered
patient support surface embodiment, comprising a
second embodiment of a patient support surface in
accordance with the subject=invention;
Figure 7 is an exploded;generally top and mostly
end perspective view of a portion of a.third
embodiment of a patient support eurface in accordance
with the subject invention (also with an outer cover
thereof removed), primarily related to a dynamic,
powered'embodiment thereof, where the power and
control elements are primarily external to the overall
construction;
Figure 8 is an exploded, generally top and mostly
end perspective view of a portion of a fourth
embodiment of a patient support surface in accordance
with the subject invention (also with an outer cover
thereof removed), primarily related to a dynamic,
powered embodiment wherein the power and control
features are primarily integrated into the overall
construction, which also incorporates lateral air
cylinder placements; and
Figure 9 is an exploded, generally top and mostly
end perspective view of .a portion of a fifth
embodiment of a patient support surface in.accordance
with the subject invention (also with an outer cover
thereof removed), primarily related to a dynamic,
CA 02593342 2007-07-26
9
powered embodiment wherein the power and control
features are primarily integrated into the overall
construction, which- also incorporates longitudinal air
cylinder placements.
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 invention.
DLTAILED DRSCRIPTSON QF TSE PRgFBRRZD MMODIM1dT8
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 subject
invention as otherwise disc,losed herewith, including
,
features as referenced in the figures. Figure 1 is a
generally top and partial'side perspective view of a
patient support surface generally 10 showing an
arrangement in accordance with the subject invention.
Patient support surface 10 and generally all other
similar embodiments in accordance with this invention
include=an exterior fitted cover 12. Cover 12 may
comprise various fabrics, such as a stretch fabric of
different materials. As understood by those of
ordinary skill in the.art, such fabric may be provided
with other technological features, such as for
minimizing moisture buildup, while yet being fluid
proof, cleanable, self-deodorizing, and/or treated
with a permanent antimicrobial agent. Pleated design
may be provided also for full integration with shear-
relieving surfaces of foam toppers contained therein.
Turning handles may be optionally provided.
Figure 1 represents an overall view for the purpose
of illustrating that patient support surface 10 may
comprise anirrangement suitable for modular assembly.
In particular, a perimeter bolster 14 is illustrated
CA 02593342 2007-07-26
in dotted line as enclosed within covering 12. Such
bolster 14 may include a pair of opposing longitudinal
elements.16 and 18 and an opposing pair of end rails
or elements 20 and 22 integrally associated therewith.
Preferably, perimeter bolster 14 comprises resilient
polyurethane materials with selected characteristics.
The several components 16, 18, 20, and 22 thereof may
be joined by gluing or the like,.as well understood by
those-of ordinary skill in the art.
Ae further shown in partial cutaway in present
Figuze 1, a foam topper generally 24 may be integrally
included within patient support surface 10.
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. It ie to be
understood that a number of longitudinal cuts or
channels may also optionally be provided (as
represented generally by dotted lines 28) for improved
shear-relief,performance or other improved features.
Such longitudinal features 28 may be practiced in any
of the embodiments herewith, though for clarity they
are represented only in present Figure 1.
As will-be well understood by those of ordinary
skill in the art, the combination of lateral channels
26 and longitudinal channels or cuts 28 results in a
plurality of separate upright support elements, the
size and construction of which may vary=over the
surface of topper 24 so as to provide selected support
characteristics. Examples of such various.
arrangements as may be practiced in combination with
the subject invention are discussed throughout
commonly owned U.S. Patent Nos. 4,862,538; 5,025,519;
CA 02593342 2007-07-26
11
5,252,278; and 5,580,504.
Figure 1 further represents in the partial cutaway
exposure thereof the fact that foam topper 24 may be
provided with particular underside features for
accommodating and receiving an air cylinder(s). In
particular, the end generally 30 of an exemplary
longitudinal. air cylinder is represented as positioned
near one end of patient support surface 10. Different
numbers and sizes of generally longitudinal air
cylinders may be practiced, and as will be further
understood with reference below to additional figures.
Laterally-positioned air cylinders may also be
practiced with variations of the subject invention.
Area 32 illustrated in present Figure 1 represents
a closeable patch or flap which may be selectively
opened for access to various aspects of the contained
features of a given embodiment. For example,
connecting air tubing may pass between exemplary air
cylinder 30 and a faceplate contained under flap 32,
with such faceplate having a valve for accessing the
interior environment of air cylinder 30. In some
embodiments, closeable flap 32 may serve as a cover
for electrical connections as well as pneumatic
c.onnections or other features to be accessed for
either operational, manufacturing, or maintenance
purposes.
It is to be understood from Figure 1 that the
interior contents, such as foam topper 24 and air
cylinder 30 (and other air cylinders) may be varied or
modified in given embodiments so as to create a
modular assembly involving cover 12, perimeter bolster
14, and other components common to several different
embodiments. Specific examples of such embodiments
CA 02593342 2007-07-26
12
are discussed in greater detail below with reference
to other figures.
Figure 2 is an exploded generally top and mostly
end perspective view of a portion of a first exemplary
embodiment generally 34.of a patient support surface
in accordance with the subject invention. Outer cover
12 is removed for clarity. Features in common with
Figure 1 and other embodiments-are marked with like
reference characters, without further specific
discussion.
In addition to being an exploded view, it is to be
understood that Figure 2 (and figures as sim'ilarly
illustrated, such as Figure,s 6, 7, 8, and 9) are
partially cutoff so as to lirimarily_ahow one end of an
exemplary subject patient support surface. Therefore,
it is to be understood that each such embodiment, such
as in Figures 2, 6, 7, 8, and 9 are at least partially
represented by the more complete view of present
Figure 1, which shows the full perimeter and size of
an exemplary patient support surface. In'other words,
it is to be further understood that additional
features of the embodiment partially shown in Figure 2
(as well as those partially shown in Figures 6, 7, 8,
and 9, respectively) as needed for a complete device
are otherwise illustrated in the overall illustration
of Figure 1, or otherwise disclosed herein by the
specification or other figures.
Figure 2 represents the exemplary use of four
longitudinal air cylinders 36, 38, 40, and 42. Each
such air cylinder has a respective end 44, 46, 30 and
48, at which a connection is made with a respective
section of air tubing 50, 52, 54, and 56. Such air
tubing interconnects with the interior of the
respective air cylinders to facilitate initially
CA 02593342 2007-07-26
= 13
establi'shing the air pressure therein and/or later
adjusting such amount of air pressure.
As represented by way of example in the embodiment
of present Figure 2, air tubing 50 and 54 are
interconnected with-a single tube 58 which emerges at
a valved opening 60.in a faceplate 62 situated under
closeable flap 32, formed in and through bolster
element 18 of perimeter bolster-14. Similarly, air
tubing 52 and 56 interconnect with a single line of
air tubing 64 which emerges at its own respective
valve. output 66 also formed in faceplate 62. While
the exemplary construction of present Figure 2
illustrates that the four air cylinders are linked in
such two interlaced pairs,:it is to.be understood that
the.respective air tubing'elements 50, 52, 54, and 56
could likewise be separately terminated in their own
respective valving elements found in faceplate 62, or
alternativery combined in other ways.
As will be discussed in greater detail below,
selective access via flap 32 to valves 60 and 66
enables the air pressure within air cylinders 36, 38,
40, and 42 to be adjusted.
Another aspect of the modular assembly of the
subject invention is represented in present Figure 2
15 by 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
0 the curvature of respective air cylinders 36 and 42.
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.
CA 02593342 2007-07-26
14
Figure 2 further represents additional aspects of
the present modular assembly, particularly as relates
to features formed on the underside surface generally
80 of 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 plii'rality 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 gen~rally top sides of the
respective air cylinders 36, 38, 40,.- and 42, such that
the depending elements 82, 84, and 86 work into the
areas between the respective air cylinders, as
discussed in greater detail below and as otherwise
represented in Figures 3A and 3B.
The resulting combination cradles and surrounds the
air cylinders, 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.
Figure 3A illustrates a generally cross-sectional
view of the Figure 2 embodiment, when assembled, so as
to show the placement relationship among the air
cylinders and various modular foam components.
referenced above. The locations of foam topper 24,
perimeter bolster components 16 and 18, and inner or
side bolsters 68 and 70 are all distinguished by the
use of differentiated cross hatching, as will be well
CA 02593342 2007-07-26
understood by those of ordinary skill in the art. For
the sake of clarity, certain reference characters and
lead lines are omitted,'such as referring to the
specific arches 88, 90, 92, and 94 and the depending
5 elements 82, 84, and 86. A general outward path of an
exemplary air tube ie represented in dotted line by
air tube 64. It is to be understood that the
discussion above with reference. to Figure 2 is fully
applicable to such features as set forth in present
10 Figures 3A, -or as otherwise presented in other
figures. -
More particularly represented in the cross-
sectional view of present F.igure 3A are wide welds 96,
98, and 100, which are credted for holding together
15 adjacently respective pairs of air cylinders. In
other words, the weld 96 existing between air
cylinders 36 and 38 helps to prevent relative lateral
separation of such air cylinders as a force is
directed there against, for example, generally in the
direction of force arrow 102.
Yn general, the air cylinders are integrally formed
so as to be reinforced, fabricated from, for example,
high tinsel woven nylon fabric fused to heavy gauge
polymeric film.' While welds 96, 98, and 100
strengthen the arrangement of respective air
cylinders, they also permit each air cylinder to react
independently to patient movement.
Yet another advantageous support feature which may
be practiced in accordance with the subject invention
is represented by present Figure 3A. In particular,
the overall support strategy achieved with the
structural arrangement-of present Figure 3A may be
enhanced by utilizing foam having different support
characteristics. For example, in relation to each
other, perimeter bolster 14 (only components 16 and 18
CA 02593342 2007-07-26
16
thereof are represented in Figure 3A) 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. For specific examples,
it will be understood by those of ordinary skill in
the art that various nomenclatures may describe
support characteristics of a given piece of foam. in
this*instance, ILD is intended to refer to the known
characteristic of so-called indentation load
deflection. Indentation load deflection (ILD) may be
defined as the number of pounds of pressure needed to
push a 50 square inch circular plate into a pad a
given percentage deflectiofi thereof. For example, a
25 percent ILD of 30 pounds would mean that 30 pounds
of pressure is required to push a 50 square inch
circular plate into a four inch pad a distance of one
inch (i.e., 25 percent of the original, unloaded
thickness).
Using a 25 percent ILD characteristic for
description purposes, perimeter bolster 14 (including
all elements 16, 18, 20, and 22 thereof) may comprise
about a 54 pound ILD, while side or inner bolsters 68
and 70 may each compripe about a 50 pound ILD and
while foam topper 24 comprises about a 35 pound ILD.
Such arrangement results in further beneficial
advantages, as discussed in greater detail below with
reference to Figure 3B.
Figure 3B represents an enlarged, partial view of
the generally right hand portion of the illustration
of present Figure 3A. In other words, such further
cross-sectional view is provided to show interaction
=with a diagrammatic representation of a patient
generally 104 who is seated on the edge of the patient
support surface generally 34. As diagrammatically
CA 02593342 2007-07-26
17
represented, the buttocks generally .106 of patient 104
.is eituated'on the upper surface of patient support
surface 34,'while the upper leg portions generally 108
are draped over a side or lateral edge generally 110
of patient support surface 34. Such position permits
the lower,legs generally 112 to hang over the side of
the patient support surface with the feet (not shown)
touching or above a floor surfkce.
Figure 3B represents an exemplary position of a
patient 104 'when sitting on (i=e=, partially over) the
edge 110 of the patient support siurface 34. Such
position may either be=desired as a stable temporary
position, or may occur during the intermediate stages
of entry onto or egress from the patient support
surface 34. In either of 'such cases;"Figure 3B
represents a number of features in accordance with the
subject invention which help to maintain a stable
support environment for the patient, for improved
patient safety. In other words, the resulting
structure and.practice of the present invention
results in roll protection, to prevent a patient from
being artificially accelerated in the direction of
arrow 114 as the patient's center of gravity passes
over the top point generally 116 of air cylinder 42.
Both the overall construction of the arrangement of
present Figure 3B, as well as the differential foam
characteristics which may be utilized, contribute to
the patient protective features described herein.
As represented in present Figure 3B, the relatively
- denser materials comprising perimeter bolster elements
16 and.side or inner bolster 70 deflect relatively
less than the deflection which occurs in relatively
softer (i.e., less dense) material of foam topper 24.
Also, when comparing Figure 3A with Figure 3B, it will
be understood by those of ordinary skill in the art
CA 02593342 2007-07-26
18
that the generally circular slot 78 formed in the
concave face 74 of side bolster 70 distorts or
otherwise deflects so as to permit controlled reaction
of air cylinder 42. 'The result is safer patient entry
and egress with maximized structural integrity, all in
an embodiment which lends itself to multiple
variations f'or modular assembly of different models
within an entire product line of related patient
support surfaces.
Ariother consequence of the patient protection
features described herewith relates to the safety of
the patient while laying down on the patient support
surface. As well understoo.d by those of ordinary
skill in the art, patients! often voluntarily or
involuntarily move on a patient support surface. Such
movpment can lead to situations where patients
approach the edge of a patient support surface. The
"edge" features described above in such circumstance
operate so as to gently prompt the patient towards the
center of the bed, but without requiring awkward
buildups or blocking elements which would otherwise
obstruct entry or egress. Hence, the resulting
arrangement in accordance with the subject invention
also facilitates safer resting and safer (i.e., better
controlled) transfers between a patient support
surface and, for example, a transporting gurney.
Another aspect of the subject invention is that
variations of the different components may be
practiced. For example, the singular generally
circular slot 78 for bolster 70 may potentially be
replaced in some embodiments with plural slots and/or
slots of different basic shapes.
Likewise, different dimensions may be practiced.
For example, side bolster 70 (and opposite side
bolster 68) may have a.height and depth of about 5
CA 02593342 2007-07-26
19
inches for each such dimension. In such instance, the
radius of curvature for curved concave face 74 may be
in a range of from about 2 inches to about 3 inches,
while the radius of curvature for circular slot 78 is
- about three-quarters of an inch. Variations of-all
such features may be practiced, so long as the basic
illustrated structure functions as described.
Figure 4 shows a greatly enlarged, isolated view of
a portion.of the exterior cover 12, focused on the
closeable flap 32 and faceplate 62 therebeneath, such
as described above with general reference to present
Figures i.and 2. In the example shown,. a pair of
valve elements 60 and 66 provide pneumatic access to
the interior of air cylinders 36, 3B, 40, and 42. As
understood by those of ordinary skill in-.the art, such
valves may preferably comprise check valves which
normally remain closed until,penetrated by a needle,
inserted for the purposes of bleeding off air or
adding aix to the enclosed environment.
In this instance, it is to be understood that air
cylinders 36, 38, 40, and 42 are operative in a
static, non-powered arrangement, such that there is no
escape or entry of air intended relative to such air
cylinders during normal operation thereof. In other
words, as situated, they operate to redistribute and
equalize air pressure along the length of the
respective air cylinders, without escape or entry of
any air during such operation. On the other hand, air
is introduced into such air cylinders whenever they
are originally outfitted at a manufacturer's location,
to suit original manufacturing specifications. In
other words, they are initially inflated to a
predetermined level.
In this instance, the respective air cylinders may
be "recharged" so as to be returned to their original
CA 02593342 2007-07-26
manufacturer's specification. In this way, any
interim leakage, for example, which may occur over
several months time during use, or due to atmospheric
differences, may be corrected in the field, such as at
5 a hospital, nursing home, or in a home healthcare
environment.
As represented by present Figure 4, any air source
may be utilized, but one preferred approach is for use
simply of a hand air pump generally 118 provided with
10 an insertion needle 120 for penetrating either valve
60 or 66 in relation to their respectively associated
air cylinders. As will be readily'understood by those
of ordinary skill in the art, handle 122 may be
utilized for forcing air o~ t through openings
15 associated with the forward or distal end of needle
120 after such needle is inserted as shown in Figure
4. In this manner, by using either valve 60 or 66,
additional air may be introduced into any of the
respbctive air cylinders.
20 As part of the practice of the present methodology
in accordance with this invention, the pump operator
need not be aware of the precise amount of air being
introduced, such that over inflation will actually
occur. Further in accordance with this invention, a
precalibrated relief valve generally 124 associated
with its own penetration needle 126 may be utilized
for bleeding off any excess air down to the
predetermined manufacturer's specification for the air
pressure within the respective cylinders.
In other words, all the operator (such as a nurse
or technician or home user) need do relative to a
given valve 60 or 66 is pump air in with pump 118 and
then subsequently bleed excess air off with
precalibrated valve 124. In this manner, the air
pressure within the respective air cylinders of the
CA 02593342 2007-07-26
21
static, non-powered embodiment is "recharged" or
returned to the original manufacturer's specification,
all without requiring sophisticated equipment or
technique. Moreover, the procedure takes only several
simple steps, which facilitates routine scheduled
practice of the method. The result is a highly
affordable air and foam mattress system for providing
a patient support surface. Such'procedures may also,
be.practiced during initial set-up, to insure no air
losses after shipment, or as part of the initial air
pressurization of the air cylinders -- in place of
such operation by the manufacturer.
Velcrol" components (well,known hook and fabric
features) generally 128, o'r snaps, or the like may be
utilized for selectively closing and opening flap 32
relative to faceplate 62. All such features will be
well understood by those of ordinary skill in the art
without requiring additional disclosure.
Figure 5 represents an isolated, enlarged view of
an exemplary sloping heel pressure relief section of a
foam topper 24 in accordance with the present
invention. Such heel pressure relief features may be
practiced in a foam topper integrally.incorporated
with patient support surfaces as illustrated in
accordance with this invention, or as part of a
separate foam topper added to the top of existing
mattresses.
Specifically, Figure 5 illustrates a side
elevational view of a portion of mattress topper 24
intended to support the heel and upper leg portion of
an exemplary patient generally 104. The upper leg
area generally 108 is supported on a "regular" portion
of mattress topper 24, as otherwise represented in the figures. Lateral cross
cuts or channels 26 may be
provided, as well as air circulation channels 130 at
CA 02593342 2007-07-26
22
the base of such cuts 26. Longitudinal cuts or
chaanels 28 may be practiced (Figure 1) but are not
seen in this view.
in the area of lower leg 112 and the area of heel
132 of foot generally 134, a number of particular
features are provided in section generally 136 of
mattress topper 24. For example, an overall angular
slope is introduced to a portibn*of the upper support
surface generally 138 of mattress topper 24, as
represented by angle generally 140. While such exact
angle may vary in a range, such as from about 4
degrees to about 10 degrees (other angles may be
practiced), approximately a.6 degree angle is
preferred in some embodiments.
A portion of such angled surface area includes a
generally flat upper support surface 142, which
extends down to a base portion or height generally
144, below which the thickness of the base 144 does
not further reduce. In other words, there is a
minimum base thickness which is maintained, despite an
angled upper surface 138 for the sloping heel pressure
relief section generally 136.
As represented best by present Figure 5, the
sloping portion is primarily achieved by a reduction
in the size and shape of the respective supporting
elements or line of elements, for example, elements
146. The progressive reduction thereof may also be
accompanied with a relatively increased size in the
circular channels 148 so as to facilitate even greater
independence of the respective elements 146 and a
greater level of air circulation for the removal of
moisture, such as perspiration. All such features
collectively achieve a redistribution or transference
of load generally from heel section 132 more onto the
greater pressure-tolerant lower legs and calves
CA 02593342 2007-07-26
23
generally 112. As a result, heel pressures are
reduced while providing greater foot support and
comf ort .
For clarity in the remaining figures, such sloping
heel pressure relief section features are not
separately indicated by reference characters, though
clearly illustrated so that those of ordinary skill in
the art may understand the oriantation of the
exemplary pressure support surfaces and the exemplary
location of 'such features relative to the illustrated
embodiments. Also, the omission of,any underside
features in the exemplary illustration of present
Figure 5 is intended to represent potential use of
such sloping heel pressure.!relief section features in
embodiments of mattress toppers utili-zed directly onto
the surfaces of existing beds, and not just as
integrated into patient support surfaces, as otherwise
illustrated herein.
Figures 6,.7, 8, and 9 represent similar
perspectives of partial illustrations of exemplary
second, third, fourth, and fifth embodiments,
respectively, of patient support surfaces in
accordance with the subject invention. Each such
figure represents a generally top and mostly end
perspective view, exploded, of a portion of a
particular form of patient support surface (with the
outer cover removed). As such, each represents
certain features as being in common, which results in
advantageous modular assembly features achieved with
the present invention. For clarity and reduced
individual description, like components have the same
reference characters as those of Figure 2, and
description related to all such elements in Figure 2
is applicable to the respective Figures 6, 7, 8, and 9
to the extent that such elements are set forth
CA 02593342 2007-07-26
24
therein, without requiring additional separate
discussion.
More specifically, Figure 6 illustrates an
embodiment of.a dynamic, non-powered patient support
surface generally 150 utilizing foam topper 24,
perimeter bolster 14 (represented by elements 16, 18,
and 20 thereof), and side or inner bolsters 68 and 70.
An exemplary number (four) of longitudinal air
cylinders generally 152, 154, 156, and.158 are
provided. In essence, they may be the same as air
cylinders 36, 38, 40, and 42, except'not as long, so
as to also accommodate.within perimeter bolster 14
other elements as discussed'herein.
More specifically, added reservoirs =160 and 162 may
include.elasticized wraps '164 and 166 respectively for
comprising resiliently actuated reservoirs associated
with -respective of the air cylinders 152, 154, 156,
and 158. Air tubing 50, 52, 54, and 56 may be
individually or in pairs connected with one or more of
the elasticized reservoirs 160 and 162 (air
connections not shown for clarity). With such
arrangement, the air level in the air cylinders
dynamically reacts to changes in pressure loading, by
pressing or pumping excess air into reservoirs 160 or
162 (by the excess loading), and alternately forcing
air.back into.the air cylinders from such reservoirs
when needed (by the resiliency of the wraps), until a
dynamic balance is achieved. Such system is referred
to as being "non-powered" since the resiliency of the
elasticized wraps 164 and 166 provides for the dynamic
action, without requiring electric power.. Complete
details of such arrangements are set forth in commonly
owned U.S. Patent Nos. 5, 649, 331 and 5r652,985.
CA 02593342 2007-07-26
It is to be understood that such dynamic, non-
powered embodiment of present Figure 6 may be provided
with other numbers of air cylinders and/or air
reservoirs, all interconnected in various fashions so
as to achieve desired operation, all without change to
the basic layout, cooperation, or function of the
perimeter bolster, foam topper (with underside
features) and side bolsters. Yt'is likewise to be
understood that all such features could be positioned
.exactly as shown, without regard to the manner in
which tubing interconnections are varied. For such
reason, the exact air tubing connections which could be
niade do not need to be separately illustrated in
present Figure 6 for an adequate understanding of the
subject invention, and so are only diagrammatically
represented therein.
Figure 7 represents a dynamic, powered embodiment
of a patient support surface generally 168 in
accordance with the subject invention, wherein the
"power" components,are generally external to the
construction. In other words, the components or
features necessary to pump-additional air.into or out
of respective air cylinders 36, 38, 40, and 42
primarily are external to arrangement generally 168.
More specifically, by way of diagrammatic
representation, and intended as representational only,
a single line 170 is represented as emerging from
arrangement 168 via perimeter bolster element 18
through a faceplate 172. Interconnection is made to a
representative means 174 for powering changes to the
air within the respective air cylinders 36, 38, 40,
and 42. Individual air tubes, paired air tubes, or a
collective air tube arrangement may all be practiced,
CA 02593342 2007-07-26
26
and is intended to be represented by the single
interconnecting air tube represented by 170.
The represented means 174 represents the potential
use of various feedback sensors, pumps, electronic
controls, and valve and manifold systems as may be
needed and/or utilized as desired in a dynamic bed
system. It should be understood that reference.to
electronic controls means both_electronics and in some
instances programmable components and their operating
software. It should also be recognized that the
illustrated arrangement of plural, respective,
longitudinal air cylinders may be controlled and
operated so as to produce an alternating pressure
feature, for periodically fherapeutically stimulating
a patient. Various constructions of such features are
well known to those of ordinary skill in the art, and
form no particular aspect of the subject invention,
outside of the context as represented by present
Figure 7.
Figure 8 represents a dynamic, powered patient
support surface generally 176 in accordance with the
subject invention,.wherein the power components
thereof are primarily internally arranged (i.e., self-
contained), and further wherein the air cylinders are
laterally positioned. Again, the embodiment of
present Figure 8 includes certain features in common
with previous embodiments, and are accordingly marked
with common reference characters, without further
discussion.
The upper surface of a foam topper generally 178
may be provided as in other embodiments (including the
sloping heel pressure relief section thereof), but has
an undersurface generally 180 which is otherwise
adjusted so that the underneath arches 190, 192, 194,
196, and the like are turned so as to be lateral
CA 02593342 2007-07-26
27
relative to the longitudinal length of the patient
support surface generally 176. Such position
corresponds with the lateral position of air cylinders
generally 198, 200, 202, and 204.
Such four air cylinders 198 through 204 may
comprise a group set of air'cylinders which are
commonly controlled for reducing pressures in the
generally lower section of a patient. An additional
grouping of lateral air cylinders (including air
cylinder 206- and other air cylinders not shown), for
example, may be provided for reducing pressures under
dynamic control in relation to the midsection of a
patient. Further air cylinders (not shown) may be
utilized in a group for dyiiamic support of the upper
portion of a patient, so that collectively a number of
sites are provided along the length of a patient for
separately dynamically controlled pressure relief.
Other arrangements may be practiced, such as four
groupb or zones of three air cylinders each, covering
respectively the head, upper torso, lower torso, and
heel sites of a patient.
A further aspect -of the embodiment of present
Figure 8 is that control means or mechanisms generally
208 may be provided contained within the arrangement
:5 uf patient support surface 176. To accommodate such
arrangement, a portion of the foam inner bolster 68
.may be cut away to provide aspace in one lateral side
adjacent the foot end of patient support surface 176.
Such control mechanism 208 may contain features as
0 similarly described above with reference to control
mechanism 174 of present Figure 7. Likewise,
interconnecting air tubes or sensor feedback paths are
not separately shown, for the sake of clarity, and due
to the fact that such features may vary among
5 different embodiments depending on the selection of
CA 02593342 2007-07-26
= 28
air cylinders,to be grouped-or not grouped for dynamic
operation. Also, it will be understood that internal
slots 76 and 78 of inner bolsters 68 and 70,
respectively, may be used for a double purpose of
providing a passageway for various of such air tube
placements, or wires or the.like for feedback
pathways.
An additional feature of present Figure 8
illustrated is use of an outside or exterior control
pendant generally 210, greatly simplified for purposes
of illustration. Such control pendant may be
electronically connected via wiring 212, which passes
through covering 12 (not shown) of patient support
surface 176 so as to inter~onnect with the control
mechanism 208 thereof. By such pendant 210, surface
176 may be programmed for different modes of
operation, such as a body site specific focus or for
an alternating pressure feature as with Figure 7,
albeit involving lateral cylinders rather than
longitudinal. Of course, any of such dynamic
embodiments may be operated for more straightforward
equalization of pressure among respective patient
sites.
Figure 9 represents a fifth embodiment of a patient
support surface generally 214 in accordance with the
subject invention, involving another version of a
dynamic, powered surface. The arrangement 214 is
similar to Figure 7 in that it makes use of
longitudinally positioned air cylinders 36, 38, 40,
and 42. At the same time, it is similar to the
embodiment of present Figure 8 because it.makes use of
internally located (i.e., self-contained) control
mechanisms 208, with an external control'pendant 210
interconnected via electrical lines 212. Other
features thereof will be understood from the use of
CA 02593342 2007-07-26
29
common reference characters and the above discussion'
of such features in"relation to other embodiments.
Also, the Figure 9 embodiment is likewise capable
of operating in various'"programmed" modes. in
addition to some of the modes discussed above, it is
capable of so-called lateral- rotation operation,
whereby a patient is literally rotated about their
longitudinal axis, up to 30 degrees, for therapeutic
stimulation.
In addition to the many variations referenced
above, it is to be further understood that other
variations may be practiced so as to combine different
features for obtaining patient support surfaces of
types not illustrated, whiYe also making use of the
L5 various foam components permitting modular assembly as
discussed above. Likewise, it is to be understood
that various of the respective illustrated embodiments
may be modified as desired. For example, specific
numbe'rs or sizes of air cylinders may be used, in
30 either longitudinal and/or lateral arrangements, or
mixed arrangements thereof. Likewise, variations may
be practiced with characteristics of different foam
components, such as varying the ILD characteristics
thereof or the constructions of certain support
:5 surfaces, such as the upper support surface of foam
topper 24. Different embodiments may also be directed
'to different sized beds (such as twin, full, queen, or
king) or to beds having different weight capacities
for special need patients. All such variations and
0 modifications are intended to come within the spirit
and scope of the subject invention.
