Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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- BACXÇROUND OF THE INVENTION
lhe present invention relates to an a:Lr sac for use on a
low air loss patien~ support system. More particularly, it
relates to an air sac for use on a low air loss bed such as
the bed disclosed in my co-pending application Serial No.
905,553 having integral means for retaini~g a patient on the
air sac when the patient is movad toward the ends thereof.
Such a bed can be used to advantage for the prevention of bed
. sores and the ~ollection of fluid in the lungs of bedridden
patients.
A number of patentsj both U.S. and foreign, disclose air
mattresses or cushions comprised o~ sets of cells which are
alternately inflated and de~lated to support a patient first
on one group of air cells and then the other group. Those
15 patents include the following U.S. patents: 1,772,310,
: ~,245,909, 2,998,817, 3,3gO,674~ 3,467,081, 3,587,568,
3,653,083, 4,068,334, 4,175,297, 4,193,149, 4,197,837,
4,225,989, 4,347,633~ 4,391,009, and 4,472,847, and the
following ~oreign patents: G.B. 959,103, Australia 401,767,
23 and ~erman 24 46 935, 29 19 438 and 28 07 038. None of the
devices discLosed in those patents rolls or alternately moves
the patient supported thereon to further distribute the
patient' 5 body weight over additional air cushions or cells
or to alternately relieve the pre~sure under portions of the
~ 25 patient 9 5 body. :
: There are; also a number ~f patents which disclose an
inflatable device o~her than an air mattress or cushion but
~: which involve alternately supplying air to a set of cells and
then to another set of ceLls. Those patents include U.S.
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patent nos. 1l14~,560, 3,595,223, and 3,867,732, and G.B.
Patent No. 1,405,333. Of those patents, only the British
patent discloses the movement of the body with changes in air
pressure in the cells of the device. None of those
references disclose an apparatus which i5 adaptable for usP
in a low air loss patient support system.
~ ritish Patent No. 946,831 discloses an air mattress
having inflatable elongated sacs which are placed side-by-
side and whiçh are in fluid communication with each other. A
valve is provided in the conduit connecting the insides of
the two sacs. Air is supplied to both sacs in an amount suf-
ficient to support the patient, thereby raising the patient
off the bed or other surface on which the air mattress rests.
Any imbalance of the weight distribution of the patient
; 15 causes the air to be driven from one sac to the other, allow-
ing the patient to turn toward the direction of the now
deflated sac. An automatic changeover valve, the details of
which are not shown, is said to then inflate the deflated sac
while deflating the sac which was originally inflated, there-
by rocking the patient in the other direction.
The device disclosed in that patent is limited in its
ability to prevent bed sore~ because when the patient rocks
onto the deflated sac, there may be insufficient air to
support the patien~ up off the bed or other surface on which
~he air mattress rests, resulting in pressure being exerted
against the patient's skin which is essentially the same as
the pressure that would have been exerted by the board or
- other surface without the air mattress. Even if there wers
enough air left in the deflated sac to support the patient,
if the air ma~tress were constructed in a low air 105s
configura~ion, the air remaining in the sac would be slowly
lost from the sac until the patien~ rested directly on the
bed or other surface with the same result. Finally, that
device is not adaptable for use on a bed having hinged sec-
tions corresponding to the parts of the patient's body lyingon the bed so that the angle of inclination of the various
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sections of the bed can be adjusted for the pa~ient's comfort
or for therapeutic reasons.
The present invention is characterized by a number of
advantages over the prior art devices, including the ability
to maintain air pressure, the ability to quickly and easily
replace one or more of the air sacs while the low air loss
bed is in operation, and the ease of adjustment of the air
pressure in the air sacs.
It i5, therefore, an object of the present invention to
provide a low air loss, water ~apor permeable air sac which
is comprised of a substantially rectangular enclosure
constructed of a water vapor permeable material, means for
connecting the inside of the enclosure with a source of gas
for inflating the enclosure, means for releasably securing
the enclosure to a low air loss bed, integral means for
: moving a patient resting on ~he top surface of the
rectangular enclosure towards the end thereof when the
enclosure i5 inflated, and integral means at the end of the
rectangular enclosure toward which the patient is moved for
retaining the patient on the top surface of the enclosure.
Another object of the present invention is to provide an
air sac with a single opening which can be quickly and easily
detached from an air bed to allow the easy replacement of the
air sac, even while khe bed is in operation.
Another object of the present invention is to provide an
:~ air sac for use on a low air loss bed capable of rolling a
patient back and forth on the bed while safely retaining the
patient thereon.
Other objects and advantages will be apparent to those
of skill in the art from the following disclosure.
SUMMARY OF THE INVENTION
These objects and advantages are accomplished in the
pres~nt invention by providing an air sac for use on a low
:~ air loss bed having a plurali~y of transversely mounted air
sacs mounted thereon comprising an enclosure for supporting a
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patient and distributing pressure over the body of the
patient to prevent pressure points and means for connecting
the inside of the enclosure with a source of gas for inflat-
ing the enclosure with gas. The enclosure ~s provided with
means for securing the enclosure to a low air loss bed and
means for moving a patient supported thereon toward one end
of the enclosure when the air sac is inflated. The air sac
is also provided with integral means for retaining the
pa~ient supported on the top surface of the enclosure when
the patient is moved toward the end of the enclosure.
BRIEF DESCRIPTION OF T~E DRAWINGS
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Figure 1 is a perspective view of a low air los~ bed
having the presently preferred embodiments of the air sac of
the present invention mounted thereto.
Figure 2 is a cross-sectional view of the bed of Fig. 1,
showing an air sac with a second air sac therebehind taken
along the lines 2-2 in Fig. 1, the second air sac being shown
in shadow lines for purposes of clarity.
Figure 3 is an end view of a presently preferred
embodiment of an air sac for use on the low air loss bed of
Fig. 1.
Figure 4 is an end view of another presently preferred
embodiment of an air sac for use on the low air loss bed of
Fig. 1.
Figure 5 is an end view of another presently preferred
embodiment of an air sac for use on the low air loss bed of
Fig. 1.
Figure 6 is an end view of another presently preferred
embodiment of an air sac for use on the low air loss bed of
FigO 1.
Figures 7A-7~ are an end view of a patient supported
upon the top surface of the air sacs of the low air loss bed
of the present inv~ntion (7D), as that pati~nt is rocked
toward one side of he frame of ~he low air loss bed (7A),
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then ~oward the other side (7C) or supported on the air sacs
when all air sacs are fully inflated (Fig. 7B).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Fig. 1, there is shown a ~ed 10 including a
frame 12. The frame 12 is comprised of a plurality of sec-
tions 14', 14'', 14''' and 14'''', hinged at the points 44',
44'' and 44''', and end members 16. The frame 12 is provided
with headboard 20 at one end and a foot board 21 at the othex
end.
The air sacs 58 ar substantially rectangular in shape,
and are constructed of a coated fabric or similar material
through which water vapor can move, but which water and other
liqui~s will not penetrate. The fabric sold under the
trademark "GORE-TEX" is one such suitable material.
Referring to Figs. 1-6, air sacs of different
configuration are shown for use according to the location at
which they are mounted on the frame 12 of bed 10. For
instance, some of the air sacs mounted to the feet baseboard
46 are of the configuration designated at reference numeral
32~o Likewise, some of the air sacs mounted to the fee~
baseboard 46 are of the configuration designated at reference
numeral 322, and all the air sacs mounted to leg baseboard 48
and seat baseboard 50 are of th~ configuration designated at
reference numeral 322. Alternatively, some or all of the air
sacs designated at reference numeral 322 can be replaced with
air sacs of the configuration shown at reference numeral 325
(see Fig. 4) or 337 Isee Fig. 6). Some of the air sacs shown
at reference numeral 322 are also mounted to head baseboard
52, as are air sacs of the configuration shown at reference
n~mexal 58.
Air sacs 58, 322, 325, 328, and 337 are constructed in
the form of a substantially rectangular enclosure, at least
the top surface 323 of which is constructed of water vapor
: permeable ma~erial as described above. Air sacs 58, 322,
325, 328 and 337 are provided with means for connecting the
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inside of the air sac enclosure to a source of gas (not
shown) to inflate the enclosure with gas in the form of the
nipple 23 ~see Figs. 2-6) which extends through the hole 54
in baseboard 50 into a gas manifold 80 mounted to baseboard
50 as shown in Fig. 2. An O-ring 68 i5 provided to seal
nipple 23 in hole 54, and extension tab 15 fits under screw
13 to hold air sac 322 in place. Aix sac 58, 322, 325, 328,
or 337 is also provided with means for releasably securing
the air sac enclosure to the low air loss bed 10 in the form
10 of a post 32, having retainer 34 on the end thereof, which
extends through hole 54 to engage the underside of baseboard
50.
Means is provided for moving a patient 348 tsee Figs.
7A-7D) supported on air sacs 322, 325, 328, or 337 toward one
side of frame 12 when air sacs 322, 325, 328, or 337 are
inflated and for retaining the patient 348 on the top surface
: 323 of air sacs 322, 325, 328, or 337 when patient 348 is
rolled or rocked towards one side of frame 12 or the other.
The means for moving patient 348 supported on air sacs 322,
325, 328, or 337 toward one side of frame 12 when the air
sacs 322, 325, 328, or 337 are inflated ~omprises a cutou~
324 in the top 323 of the substantiallv rectangular shape of
each of the air sacs 322, 325, 328 or 337.
Each air sac 322, 325, 328, or 337 is also provided with
means for retaining a patient 348 on the top surface 323 of
the air sac 322, 325, 328, or 337 when patient 348 is rolled
toward the side ~f frame 12 by the inflation of air sacs 322,
325, 328, or 337 in the form of a pillar 326 which is
integral with each air sac 322, 325, 328, or 337 and which~
when inflated, projects upwardly to form the end and corner
of the substantially rectangular enclosure of air sac 322,
325, 328, or 337O
As shown in Fig. 1, a plurality of air sacs 58, 322,
: 325, 328 and/or 337 i5 mounted transversely on the ~rame 12
of bed 10. The air sacs 322, 325, 328, or 337 are divided
into a first set in which the pillar 326 and cutout 324 are
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closer to one side of bed fxame 12 than the other and a
second set of air sacs 322, 325, 328, or 337 in which the
pillar 326 and cutout 324 are closer to the second side of
the bed frame 12. The air sacs 322, 325, 328, or 337 of the
first set and the air sacs 322, 325, 328, or 337 of the
second set alternate with each other along the length of
baseboards 46, 48, 50, and 52. As will be explained, the
first set of air sacs 322, 325, 328, or 337 is inflated with
air from a gas source (not shown), thereby causing the
patient 348 supported thereon to be rolled toward ~he first
side of bed frame 12 and then deflated while the second set
of air sacs 322, 325, 328, or 337 is inflated, thereby moving
the patient 348 supported thereon toward the other side of
bed frame 12 (see Fig. 7A-7D). The air pressure in the sets
of air sacs is monitored by gauges 241.
~The air sacs 58 which are mounted on head baseboard 52
;are provided with a flat top surface 323 so that the head of
patient 348 is retained in a relatively constant position
while the body of patient 348 is alternately rolled first
toward one si.de of the bed frame 12 and then back toward the
other side of bed frame 12. Referring to Fig. 3, an air sac
58 is shown for use under the head of patient 348. ~ir sac
58 is substantially rectangular in shape, but is provided
with a slanted top surface 323 in the area 331 adjacent to
corners 448. The total height of air sac 58 i~ less than the
height of air sacQ 322, 325, 328, and 337 because when
patient 348 lies upon air sacs 322, 325, 328, and/or 337, the
heavier portions, i.e., the portions of the body other than
the head, sink into those air sac~ 322, 325, 328, and/or 337
as shown in Fig. 7D. When the patient 348 sinks into air sacs
322, 325, 328, and/or 337, the head rests evenly on air sacs
58 because the head does not sink into air sacs 58 as far as
the other portions of the patient's body sinks into the air
sacQ 322, 325, 328, or 337 on which the rest of the body is
supported.
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The air sacs 328 ~oun~ed on the foot baseboard 46 are
also provided with a cutout 324 and pillar 326 as described
for the air sacs 322. Additionally, ~ir sacs 328 are pro-
vided with a hump 330 so that the legs of patient 348 are
relatively restrained from movement during the alternate back
and forth movement of patient 348, thereby helping to retain
the patient 348 on the top surface 323 of air sacs 58, 322,
325, 328, and 337 as well as helping to distribute the
pressure exerted against ~he skin of pat:ien~. 348 over an
increased area. Referring to Fig. 5~ there is shown an end
view of an air sac 328 having hump 330 formed in the top
surface 323 thereof. As can be seen, when air sac 328 is
inflated, hump 330 and pillar 326 project upwardly to help
prevent the rolling of patient 343 too far to one side of air
sac 328 or the other.
As noted above, some of the air sacs mounted to foot
baseboard 46, and preferably all the air sacs mounted to legs
baseboard 48 and seat baseboard S0, are of the configuration
shown in Fig. 2 at reference numeral 322. Alternatively, air
sac 322 is constructed in the configuration shown at
reference numeral 325 of Fig. 4 or reference numeral 337 of
Fig. 6. Air sac 325 is provided with cutout 324 of approxi-
mately the same depth as the cutout 324 of air sacs 322, 328
and 337, but the top surface 323 of air sac 325 in the area
329 is less than the slope of the top surface 323 in the area
329 of air sac-~ 322, 328, and 337. Air sac 325 is also
provided with an area, indicated by reference numeral 327, in
which the slope of the wall of cutout 324 is reversed. The
corner 335 of air sac 325 acts as a balance point as shown in
FigsO 7A and 7C as the patient 348 is alternately rolled from
one end of the air sac 325 to the other such tha the body
weight of patient 348 is used to assist in the rolling of
patient 348 towards each end of air sac 325. To further
distribute the pressure exerted by air sac 325 against the
shoulder and hip of patient 348 when the patient is rolled to
the position shown in Figs. 7A and 7C, the cutout 324 is
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provided with a sloped portion, indicated at reference
numeral 339, of the wall of pillar 326^ Air sac 325, in
conjunction with the adjustment of the air pressure in the
air sacs 58, 322, 328, and/or 337, is used under different
portions of the body of patient 348 to increase or decrease
the extent and speed with which patient l48 is rolled from
one side of bed frame 12 to the other. Fox instance, air sac
325 is particularly well-suited for use under the shoulders
of a patient 348.
It will be understood by those skilled in the art who
have the benefit of this disclosure that, although patient
348 is shown supported on air sacs having the configuration
shown at reference numeral 325 in Figs. 7A-7D~ the patien
348 can also be alternately rolled back and ~orth when
supported on any of the air sacs 322, 328, or 337.
Regardless of the configuration utilized, when one set of air
sacs 322, 325, 328 or 337 is inflated, one side of patient
348 drops into cutout 324, causing the patient 348 to roll
toward one end of the air sac 322, 328, 328, or 337. As that
20 set of air sacs 322, 325, 328, and/or 337 is deflated and the
second set of air sacs 322, 325, 328/ and/or 337 is inflated,
patient 328 is first returned to the horizontal position
shown in Fig. 7D and then rolled toward the other end of air
sacs 322, 325, 328, and/or 337.
As noted above, each of the air sacs 58, 322, 325~ 328,
and 337 forms a substantially xectangular enclosure, the
dimensions of the rectangle being approximately 18 x 39
; inches when unin1ated. When inflated, the enclosure
mea~ures approximately 16 x 36 inches. Each is provided with
30 a baffle 460 attached to the inside of side walls 61 (see
Figs. 1 and 2~ which holds the side walls 61 against bowing
when the air sac 58, 322, 325, 328, or 337 is inflated. Each
of the corners 448 has a radius of curvature of approximately
three inches, and the depth of cutou~ 324 in the direction
shown by line 451 ran~es from approximately eight to
approximately thirteen inches, the presently preferred
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dimension being about ten inches. The dimension of pillar
326 of air sacs 325, 328, and 337 in the direction shown by
line 450 ranges from approximately five to approximately
twelve inches, the presently preferred dimensions being from
about seven to about twelve inches. That range of dimensions
along line 450 gives pillar 325 sufficient bulk, and
therefore suffici nt rigidity when inflated, to prevent, in
conjunction with baffle 460, the forcing of the pillars 326
ou~wardly from the sides of the bed frame 12 when both se~s
of the air sacs 58, 322, 325, 328, and 337 are inflated
either partially, i.e., when patient 348 i.s in the position
shown in Fig. 7D, or fully inflated, as when patient 328 is
in the position shown in Fig. 7B. The configuration of air
sac 325 (see Fig. 4) is even more effective at preventing
that out~ard movement of pillar 326 because of the sloped
portion 339 of the wall of pillar 326 toward the bottom of
cutout 324, and it will be understood by those skilled in the
art who have the benefit of this disclosure that any or all
of the pillars 326 of air ~acs 322, 328 or 337 can be
provided with a similarly sloped portion 339.
Referring to Fig. 2, the dimension of the top surface
: 323 of air sac 322 along lin~ 459 is approximately nineteen
inches. Top surface 323 then drops off into cut out 324 in a
curve 464 of approxLmately a three inch radius along surface
~ 25 32g. The dimension of cutout 324 in the direction shown by
:~ line 462 ranges from abou~ five to about ten inches,
: depending upon the dimension of pillar 326 in the direction
of line 450, the presen~ly preferred dimension being
approximately seven inches.
Referring to Fig. 4, the dimensio~ of cutout 324 in the
direction shown by line 452 is approximately five to ten
in~hes. The slope of the reversed portion 327 of the top
surface 323 of air sac 325 is determined by the dimension of
line 461, which in a presently preferred embodiment is
between two and five inches, depending upon th~ dimen~ion of
lines 450 and 452, all of which can be varied depending upon
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the particular operating mode desired and the weight and size
of patient 348.
The dimensions of air sac 328 (Fig~ 5) are as follows.
As noted above, the dimension o pillar 326 in t~e direction
5 of line 450 can be varied from about five to about twelve
inches, as can the dimension of cutout 324 in the direction
of line 452, depending upon the dimension of line 450. The
dimension of hump 330 on air sac 328 in the direction shown
by line 454 is approximately ~ive inc:hes, and in the
direction shown by line 45S, the dimension is approximately
two inches. The dimension of surface 3330 as shown by line
458 is approximately fourteen inches.
~ eferring now to air sac 337 (Fig. 6), the dimension of
the surface 3~9 in the direction shown by line 453 is
approximately twenty inches, and that surface 329 drops off
into cutout 324 in a curve 455 of approximately a three inch
xadius along a surface 466 having a steeper slope than the
surface 32~. The dimension of pillar 326 and cutout 324 can
be varied as described above with reference to air sacs 322,
325 and 328.
The use of individual air sacs 58, 322, 325, 328, or 337
; ra~her than a single air cushion which runs the length of ~ed
frame 12 allows the replacement of individual sacs should one
develop a leak, need cleaning or o~herwi~e need attention.
When it is desired to remove an individual air sac 58, 322,
325, 328, or 337 from its xespective baseboard 46, 48, 50, or
52, post 32 and retainer 34 are removed from hole 54 (see
Fiq. 2). Nipple 23 is then rotated until extension tab 15
rotates out of engagement with screw 13 and nipple 23 is then
pulled firmly to remove it from hole 54.
The hump 330 in air sacs 32g provides a longitudinal
barrier along the top surface of the air sacs 378 such ~ha~
~ one of the legs of patient 348 is retained on either side of
; ~hat longitudinal barrier even during the alternatiny in-
flation and deflation of the air sacs 328. In this manner,
the hump 330 prevents patient 348 from rolling too far to one
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end of air sac 328 or the other. Further, the legs of
patient 348 do not slide and/or rub together while patient
348 is being alternately rolled from one side of the bed
frame 12 to the other. It will be understood by those
skilled in the art that the air sacs 328 havinq the humps 330
therein can be replaced by air sacs 322, 325, or 337
depending upon the type of therapy and the extent of motion
desired for a particular patient.
Although the present invention has been described in
terms of the Xoregoing preferred embodiments, this descrip-
tion has been provided by way of explanation only and is not
to be construed as a limitation of the invention, the scope
of which is limited only by the following claims.
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