Inflatable cushion for supporting an extremity

An inflatable cushion for elevation of an extremity with respect to a surface supporting the cushion including an inflatable bladder having first and second opposite ends and inner and outer faces. The bladder is equipped with an air inlet for admitting air into the bladder for inflation of the bladder which includes a valve to selectively seal and unseal the air inlet. The first and second ends of the bladder may be fastened together by cooperating fasteners attached to each end. A lining made of a soft absorbent material substantially covers the inner face of the bladder. The bladder may be inflated, wrapped around the extremity and secured by the fasteners so that the bladder completely encircles the extremity. As applied to the extremity, the inner face of the bladder faces inwardly with the lining disposed between the bladder and the extremity and engaging the extremity. An area of the inner face underlying the extremity resiliently deforms under the weight of the extremity such that the weight of the extremity is supported substantially uniformly over the underlying area. The outer face of the bladder faces outwardly with a portion of the outer face engaging the surface.

BACKGROUND OF THE INVENTION 
This invention relates generally to medical devices for supporting 
extremities and more specifically to an inflatable cushion for elevated 
support of an extremity. 
Elevation of an extremity has several well known therapeutic applications, 
including reducing swelling by encouraging gravitational flow of blood out 
of the extremity. Moreover, supporting the extremity away from other 
surfaces, such as a bed mattress, prevents the occurrence of bed sores and 
promotes the healing of damaged tissue. In the past, elevation of the 
extremities has been accomplished primarily through the use of pillows or 
cushions, used individually or stacked to achieve an appropriate 
elevation. Air mattresses, padded boots and padded socks have been used to 
cushion the extremity at a pressure point (e.g., the back of the heel or 
the elbow) to prevent the occurrence of bed sores. 
Bed sores are a common problem among patients, and particularly older 
patients, who are confined to bed with a limited ability to move. Pillows, 
padded boots and padded socks are relatively soft and deformable, but they 
lack resiliency so that the weight of the extremity tends to be supported 
over a small area of the extremity, causing a pressure point. Although air 
mattresses are resilient, a disproportionately high amount of its weight 
is supported over a small area of the extremity such as the heel or elbow. 
Other devices, such as small inflatable annular rings can support the heel 
or elbow away from the bed, but these devices still support the weight of 
the extremity over such a small area that circulation around the heel or 
elbow often is cut off. The existence of the pressure point causes pain in 
the extremity because of the concentration of force on a small surface 
area of the extremity. The presence of a pressure point leads to break 
down of the skin tissue causing a bed sore, and the presence of an open 
wound raises the potential for infection. 
If the extremity can be moved the pressure point may be changed, but the 
pain will only recur in time. Moreover, movement of the extremity can 
cause the extremity to fall off the pillows or cause a stack of pillows to 
fall over. This is particularly a problem when a patient must have his 
extremity elevated for an extended period of time and changes position in 
bed periodically to maintain comfort. In addition, the patient's skin may 
have an allergic reaction to the material of the pillow, padded boot or 
padded sock. 
SUMMARY OF THE INVENTION 
Among the several objects of the present invention may be noted the 
provision of an inflatable cushion for elevation of an extremity which 
supports the extremity comfortably, preventing the occurrence of pressure 
points; the provision of such a cushion which maintains elevation despite 
movement of the extremity; the provision of such an inflatable cushion 
which prevents breakdown of skin contacting the cushion; the provision of 
such an inflatable cushion which reduces the chance of an allergic 
reaction of the skin contacting the cushion; the provision of such an 
inflatable cushion which inhibits growth of infectious bacteria adjacent 
the skin; the provision of such an inflatable cushion which is washable 
and requires little space to store when not in use; the provision of a 
cushion which is lightweight; and the provision of such an inflatable 
cushion which is inexpensive and thus readily afforded by individuals. 
Generally, an inflatable cushion constructed according to the principles of 
the present invention comprises, an inflatable bladder having first and 
second opposite ends and inner and outer faces. The first and second ends 
of the bladder may be releasably fastened together by fastening means. 
Inlet means provided for admitting air into the bladder for inflation of 
the bladder may be selectively sealed and unsealed by selective sealing 
means. Lining means made of a soft absorbent material substantially covers 
the inner face of the bladder. The bladder is adapted to be inflated, 
wrapped around the extremity and secured by the fastening means such that 
the bladder completely encircles the extremity. When applied to the 
extremity, the inner face of the bladder faces inwardly with the lining 
means disposed between the bladder and the extremity and engaging the 
extremity. An area of the inner face underlying the extremity resiliently 
deforms under the weight of the extremity such that the weight of the 
extremity is supported substantially uniformly over the underlying area of 
the inner face. The outer face of the bladder faces outwardly with a 
portion of the outer face engaging the surface. 
Other objects and features of the present invention will be in part 
apparent and in part pointed out hereinafter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings, an inflatable cushion of the present invention, 
indicated in its entirety by the numeral 10, is shown to include an 
elongate bladder 12 made of a flexible, air impermeable material (e.g., 
vinyl) and having a first end 13 and a second end 14 longitudinally 
opposite the first. Fastening means indicated generally at 16 is provided 
for releasably fastening the first and second ends 13, 14 of the bladder 
together. The bladder 12 further includes an inner face 18 and an outer 
face 20, the directions "inner" and "outer" describing the relationship of 
the faces when the cushion 10 is applied to an extremity as described 
below. The bladder 12 of the preferred embodiment is approximately 32 
inches long and 7 inches wide, although the precise dimensions are not 
critical to the invention. Inlet means, including a tube 24 projecting 
outwardly from an opening the bladder 12, is provided for admitting air 
into the bladder for inflating the bladder. A valve (broadly "selective 
sealing means") incorporated in the tube 24 allows the inlet means to be 
selectively sealed, by pushing the tube inwardly toward the bladder 12, or 
unsealed by pulling the tube outwardly from the bladder. The valve is a 
push-pull valve, model no. 320-AC, sold by Halkey-Roberts, Inc. of St. 
Petersburg, Fla. A lining 28 (broadly "lining means") comprising an 
elongate piece of lambs wool or similar soft absorbent material 
substantially covers the inner face 18 of the bladder. 
The cushion 10 is particularly designed and constructed for elevation of an 
extremity (e.g., a leg L as shown in FIG. 1) with respect to a surface S, 
such as a mattress, supporting the cushion. In the following, the cushion 
10 of the present invention will be described as applied to the leg L. 
However, it is to be understood that the cushion 10 may be used to elevate 
any of the extremities. The bladder 12 may be inflated by pulling out the 
tube 24 to open the valve and forcing air into the bladder through the 
tube. Although the bladder 12 is preferably filled with air, it is to be 
understood that the inflation of the bladder 12 as described herein may 
include filling the bladder with any gas or with a liquid. The bladder 12 
may then be wrapped around the leg L and its first and second ends 13, 14 
secured together by the fastening means 16 so that the bladder 12 
completely encircles the leg. As applied to the leg, the inner face 18 of 
the bladder 12 faces inwardly toward the leg with the lining 28 being 
disposed between the inner face and the leg and engaging the leg. An area 
A of the inner face 18 underlying the lining 28 and the leg L and 
supporting the leg is illustrated by an outline in phantom in FIG. 2. This 
area A of the inner face 18, supported by the air inflating the bladder 
12, resiliently deforms under the weight of the leg such that the weight 
of the leg is supported substantially uniformly over the area A and no 
pressure points are present. The cushion 10 is applied to the fleshy 
portion of the leg generally at the calf which lacks any bony 
protuberances. By supporting the leg away from the normal pressure point 
(i.e., the heel) at a fleshy portion of the leg, the weight of the leg is 
applied uniformly over the area A of contact with the cushion. 
The outer face 20 of the bladder 12 faces outwardly and a portion of the 
outer face engages the surface S on which the leg L is supported. Because 
the bladder 12 completely encircles the leg, the cushion 10 will 
continually support the leg in its elevated position with respect to the 
surface S despite movement of the leg. This is of particular advantage to 
a person who must lie down for extended periods of time with his leg 
elevated. In order to remain comfortable, the person must move his body to 
shift the portions of this body which contact the supporting surface (e.g, 
bed mattress) which will inevitably result in movement of the elevated leg 
L. The cushion 10 of the present invention allows movement of the leg to 
occur while maintaining the appropriate elevation of the leg. Encirclement 
of the leg L by the cushion 10 also provides a barrier preventing 
inadvertent contact of the leg L with the other leg. This is particularly 
important when the leg is healing from tissue damage (e.g., burns), to 
prevent pain and/or further damage to the tissue. 
To facilitate bending of the inflated bladder 12 necessary for wrapping the 
cushion 10 around the leg L, the bladder has been constructed with a 
plurality of inflatable sections 36 separated by regions indicated 
generally at 38 which retain their flexibility despite inflation of the 
bladder (FIG. 3). As shown in FIG. 4, the bladder 12 further includes 
internal opposing walls designated 40 and 42 respectively, which are 
connected together at their edge margins to define the airtight interior 
of the bladder. To form the flexible regions 38 of the bladder, portions 
of the walls 40, 42 directly opposite each other are joined together in 
two places along the length of the bladder 12 to form sealed rectangular 
pockets 44 extending transversely of the bladder. The sealed pockets 44 
remain uninflated despite inflation of the bladder 12. It is to be 
understood that a cushion may have greater or fewer than two flexible 
regions and still fall within the scope of the present invention. Because 
the sealed pockets 44 do not inflate despite inflation of the remaining 
portions of the bladder 12, they remain flexible and bend easily as the 
cushion 10 is wrapped around the leg L. 
The flexible regions 38 also include passage means 48 for fluid 
communication between adjacent sections 36 of the bladder 12. The sealed 
pockets 44 do not extend the entire width of the bladder 12 and each of 
their longitudinal ends are spaced from a corresponding longitudinal edge 
of the bladder. This space between the ends of the sealed pockets 44 and 
corresponding adjacent edges of the bladder 12 defines the passage means 
48 through the flexible regions 38. Thus, the entire bladder 12 may be 
inflated from a single air inlet means (tube 24) in one of the sections 
36. Although the passage means 48 are inflated, they constitute only a 
small portion of the flexible region 38 and therefore do not, despite 
their inflation, add any appreciable rigidity to the flexible regions. 
The lining 28 of synthetic lamb's wool provides a soft, comfortable surface 
for engagement of the leg L with the cushion L which prevents irritation 
and breakdown of the skin tissue contacting the cushion 10. Therefore, 
infection caused by breakdown of skin tissue is avoided. Moreover, the 
synthetic lamb's wool is a hypo-allergenic material which protects the 
skin from an allergic reaction despite extended contact with the lining 
28. Growth of infectious bacteria on the skin is inhibited by the lining 
28. Persons wearing the cushion 10 for extended periods will excrete body 
fluids (e.g., sweat) inside the cushion. The absorbent lining material 
draws away from the skin sweat and other body fluids which would otherwise 
promote bacteria growth on the skin leading to infection. The lining 28 
may be made of other absorbent, hypo-allergenic material and still fall 
within the scope of the present invention. The lining 28 is releasably 
attached to the inner face 18 of the bladder by three straps 52 spaced 
longitudinally of the bladder 12 and by snap fasteners 53 close to the 
first and second ends 13, 14 of the bladder. The straps 52 extend 
transversely across the bladder 12 and are attached at their opposite ends 
to corresponding longitudinal edge margins of the bladder. The lining 
material is washable. Thus, the lining 28 may easily be removed, washed 
and reattached for repeated use over a long period of time. 
To secure the cushion 10 to the leg, the bladder 12 is provided with a 
first flexible fastening flap 56 at the first end 13 of the bladder and a 
second flexible fastening flap 58 at the second end 14 of the bladder 12. 
The fastening means 16 preferably comprises a hook and loop type fastener 
(commonly referred to by the trademark VELCRO). The fastener includes 
first and second fastener elements indicated at 60 and 62, respectively. 
Each fastener element comprises a rectangular sheet of hook and loop 
material. The first fastener element 60 is carried by the first fastener 
flap 56 on the inner face 18 of the bladder (FIG. 2), and the second 
fastener element 62 is carried by the second fastener flap 58 on the outer 
face 20 of the bladder (FIG. 3). When the bladder 12 is wrapped around the 
leg, the first flap 56 overlaps the second flap 58 so that the fastening 
elements 60, 62 may be engaged to hold the cushion 10 around the leg. The 
fastening elements are elongate so that the diameter enclosed by the 
cushion 10 may be changed according to the size of the leg and to the 
desired tightness. The compartmentalization of the bladder 12 into three 
sections leaves gaps between the leg and bladder when the cushion 10 is 
wrapped around the leg. The adjustability of the cushion 10 and the 
provision of gaps helps to assure that the cushion will not cut off the 
flow of blood to the foot. 
In view of the above, it will be seen that the several objects of the 
invention are achieved and other advantageous results attained. More 
specifically, it may be seen that the inflatable cushion 10 of the present 
invention supports the elevated extremity comfortably on a cushion of air. 
The inner face 18 of the inflated bladder 12 may resiliently deform under 
the weight of the extremity to support the weight of the extremity 
substantially uniformly over the area of the inner face of the bladder 
underlying the extremity, which prevents the occurrence of pressure points 
on the extremity. Pressure points cause pain, because the weight of the 
extremity is supported on only a small area of the extremity, as well as 
irritation and breakdown of the skin tissue. The flexible regions 38 of 
the bladder 12 and fastening means 16 allow the cushion 10 to be easily 
wrapped around the extremity and secured on the extremity so that although 
the person wearing the cushion may move around on the supporting surface 
S, elevation of the extremity is maintained. The ability to maintain 
elevation despite movement of the extremity provides a considerable 
advantage over elevating the extremity by propping it on a pillow or the 
like. The pillow, unlike the cushion 10, has no attachment to the 
extremity, and thus will not move with the extremity. Therefore, it is 
likely, as the persons moves to find a comfortable body position, that the 
extremity will occasionally fall from the pillow causing pain and 
annoyance. Further, the cushion 10 supports the extremity away from the 
bony protuberances, such as the heel, so that the weight of the extremity 
can be distributed uniformly over its area of contact with the cushion. 
The cushion 10 encircles the extremity so that as the extremity is turned 
a new portion of the outer face 20 of the bladder engages the surface S to 
maintain elevation of the extremity. The lining 28 made of synthetic 
lamb's wool which contacts the extremity is soft, absorbent and 
hypo-allergenic to prevent breakdown and infection of the skin. When not 
in use, the bladder 12 can be deflated and the cushion 10 folded into a 
compact configuration for storage. The cushion 10 of the preferred 
embodiment described herein weighs only 6.8 ounces when inflated with air 
and thus it comfortable to wear. The cushion 10 of the present invention 
is simply designed and made of inexpensive materials so that it is 
affordable for the average individual. Thus, persons such as diabetics 
suffering from chronic swelling may use the inflatable cushion of the 
present invention in their own home for reliable comfortable elevation of 
the swollen extremity. 
As various changes could be made in the above constructions without 
departing from the scope of the invention, it is intended that all matter 
contained in the above description or shown in the accompanying drawings 
shall be interpreted as illustrative and not in a limiting sense.