U.S. patent application number 10/022466 was filed with the patent office on 2003-06-19 for adherent orthotic pad.
Invention is credited to Gilman, Thomas H., Glaeser, Christopher T..
Application Number | 20030110662 10/022466 |
Document ID | / |
Family ID | 21809739 |
Filed Date | 2003-06-19 |
United States Patent
Application |
20030110662 |
Kind Code |
A1 |
Gilman, Thomas H. ; et
al. |
June 19, 2003 |
Adherent orthotic pad
Abstract
An orthotic pad is disclosed for reducing pressure and shear
stresses on dermal and muscle tissue in treatment areas extending
over bony prominences. This pad includes a hydrocolloid-containing
adhesive body having oppositely-facing non-parallel first, and
second major surfaces. The pad is formed of a soft, deformable and
shape-recoverable adhesive material in which particles of at least
one moisture-absorbing and moisture-swellable hydrocolloid material
are dispersed. The first surface of the pad is contoured to match
that of the treatment area for adhesively engaging and covering
such area, and the second surface has a developed shape for
corrective redistribution of external forces exertable against the
treatment area to prevent further damage from pressure or shear
forces, promote the healing process and, in appropriate cases,
provide orthopedic correction.
Inventors: |
Gilman, Thomas H.; (Spring
Grove, IL) ; Glaeser, Christopher T.; (Grayslake,
IL) |
Correspondence
Address: |
MARSHALL, GERSTEIN & BORUN
6300 SEARS TOWER
233 SOUTH WACKER
CHICAGO
IL
60606-6357
US
|
Family ID: |
21809739 |
Appl. No.: |
10/022466 |
Filed: |
December 13, 2001 |
Current U.S.
Class: |
36/43 ; 36/140;
36/71; 36/93 |
Current CPC
Class: |
A43B 7/226 20130101;
A43B 17/102 20130101; A43B 7/1464 20220101; A43B 7/141
20130101 |
Class at
Publication: |
36/43 ; 36/140;
36/71; 36/93 |
International
Class: |
A43B 013/38; A43B
023/00 |
Claims
1. An orthotic pad for reducing pressure and shear stresses on
dermal and muscle tissue in a selected treatment area extending
over a bony prominence, comprising a hydrocolloid-containing
adhesive body having oppositely-facing non-parallel first and
second major surfaces and comprising a soft, deformable and
shape-recoverable adhesive material in which particles of at least
one moisture-absorbing and moisture-swellable hydrocolloid material
are dispersed; said first surface being contoured to match the
contour of said treatment area for adhesively engaging and covering
said area; said second surface having a selected shape different
than said contour of said first surface; and a protective layer
covering said second surface.
2. The orthotic pad of claim 1 in which said protective layer is of
substantially uniform thickness and conforms with said surface
shape of said second surface.
3. The orthotic pad of claims 1 or 2 in which said protective layer
is flexible.
4. The orthotic pad of claims 1 or 2 in which said protective layer
is rigid.
5. The orthotic pad of claims 1 or 2 in which said second surface
is generally planar.
6. The orthotic pad of claims 1 or 2 in which said second surface
is non-planar and of a developed shape for corrective
redistribution of external forces exertable against said treatment
area.
7. A foot orthotic for reducing pressure and shear stresses on
dermal and muscle tissue in and about a wound area of treatment,
comprising a hydrocolloid-containing adhesive body having
oppositely facing non-parallel first and second major surfaces and
comprising a soft, deformable and shape-recoverable adhesive
material in which particles of at least one moisture-absorbing and
moisture-swellable hydrocolloid material are dispersed; said first
surface being contoured to match the contour of said treatment area
for adhesively engaging covering said area; said second surface
having a selected shape different than said contour of said first
surface; and a protective layer covering said second surface.
8. The foot orthotic of claim 7 in which said protective layer is
of said substantially uniform thickness and conforms with said
surface shape of said second surface.
9. The foot orthotic of claims 7 or 8 in which said second surface
is generally planar.
10. The foot orthotic of claims 7 or 8 in which said second surface
is non-planar and of a developed shape for corrective
redistribution of external forces exertable against said treatment
area.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
[0001] Pressure ulcers are areas of skin death caused by excessive
pressure or shear, either one of which will close off the flow of
blood in the skin vessels. In general, the risk of tissue death is
increased with higher levels of pressure or shear stress, and with
longer duration of the pressure or shear insult.
[0002] Bony prominences are concentrators of pressure, and so skin
over these areas on the body is especially at risk to pressure
injury. Such areas where bone is not padded much by muscle also can
be areas where high shear stresses in the skin are encountered, as
a person sits, lies, or stands on a surface.
[0003] In healthy individuals, the body is constantly repositioned
so as to relieve areas of excessive pressure and shear. Even in
sleep, an individual senses the need to reposition the body to
relieve pressure and shear, and does so many times throughout the
night.
[0004] Certain individuals are impaired in their ability to either
sense the need to reposition, or in their ability to do so. For
example, an individual who is recovering from hip surgery may feel
the need to move to another position as he/she lies bed, but may be
unable to do so. Other individuals may be so critically ill that
they are not aware of the need to reposition their bodies to
relieve areas of the skin circulation that are compromised by
pressure or shear stresses. Such patients are especially prone to
developing ulcers in the sacrum, coccyx, and heel areas.
[0005] An extreme case is the individual that has no sensation in
the skin at all, such as a paraplegic. These people cannot feel the
skin that is in contact with a chair's surface, and so are very
likely to develop pressure ulcers on the skin where they sit every
day. They simply have no way of knowing when it is necessary to
reposition themselves, or to know when the repositioning was
effective. Such patients often develop pressure ulcers over the
ischium.
[0006] Diabetic individuals have this same problem with their feet.
Their disease results in peripheral neuropathy, where the nerves of
the feet no longer function. Since their sensory nerves are not
functioning, they cannot know when pressure or shear has become
excessive in their feet. An object in the shoe that is causing a
pressure ulcer is unnoticed. Excessive pressure over a metatarsal
bone is unnoticed. Shear due to a certain pattern of walking, or
due to an unfavorable shoe fit, is unnoticed.
[0007] The motor neurons in the feet of diabetics are also affected
by the disease, and this can lead to muscle deformities. These
muscle problems will alter the structure of the foot, so the foot
is positioned in an abnormal way during walking. This leads to
areas of the skin that see abnormally high pressure and shear as
the person walks. The muscle abnormalities can also lead to an
altered gait, or way of walking, so that both feet are affected by
an abnormality developed in one foot.
[0008] To deal with these problems, diabetics are often given
custom orthotics in the form of relatively rigid shoe inserts that
are made to match the surface of the bottom of the foot on one
side. The other side of the orthotic is designed to contact the
shoe surface in such a way as to help correct for the foot
deformity and resulting gait abnormality. Using the orthotic in the
shoe helps to normalize the way pressure and shear are distributed
on the foot during walking. However, such custom orthotics are
neither adhesive nor absorbent. As a result, the orthotics may
easily become misaligned with the bottom of the foot to which they
are custom designed to fit, thereby potentially compounding the
problem.
[0009] Diabetics seem to be especially sensitive to shear damage.
Their blood vessels are more fragile than those of normal
individuals, so shear stress can cause bruising more easily in
diabetics. This is a problem in the foot, because shear is a normal
part of the walking process.
[0010] Once a pressure ulcer has developed, treatment will fail
unless the pressure and shear issues are resolved. For example, in
diabetics, if an ulcer is present on the plantar surface of the
foot, this ulcer will not heal unless measures are taken to ensure
that toe ulcer area is protected from pressure and shear damage
during walking. Even very brief episodes of excessive pressure or
shear can damage the very fragile tissue, and set the healing
process back. It is not practical to ask a patient to refrain
completely from walking for the months required to heal an ulcer.
Orthotics can help, but even an evening trip to the bathroom in
bare feet can cause significant damage to the wound site.
[0011] One strategy that has been tried with success in these
situations is the total contact cast. A doctor encloses the foot in
a plaster cast designed so that walking will not result in further
damage to the wound area. This is, in a sense, an orthotic that is
always in place, and in fact cannot be removed except by the
doctor. There are some disadvantages to the total contact cast,
however. One cannot reach the wound for dressing changes. One
cannot inspect the wound, and the skin around the wound, for
developing problems. The cast itself can cause pressure points if
it is not optimally applied, and again this cannot be detected
without removing and then reapplying the cast. Applying the cast is
a time consuming process that requires some skill.
[0012] An important aspect of this invention therefore lies in
providing an orthotic device that is particularly effective in
eliminating or reducing pressure and shear stresses on dermal and
muscle tissues in treatment areas extending over bony prominences.
The device takes the form of an adhesive absorbent pad with a
body-contacting surface contoured to conform with the skin surface
in the area of treatment and with an opposite surface of a
different shape determined by the surfaces or objects to be engaged
and the deformities if any to be corrected. Specifically, the pad
includes an adhesive body or layer of a soft, deformable and
shape-recoverable, pressure-sensitive adhesive material in which
particles of at least one moisture-absorbing and moisture-swellable
hydrocolloid material are dispersed. The oppositely-facing major
surfaces of the pad are non-parallel, with an adhesive body-facing
first surface being contoured to match the shape of the treatment
area and the oppositely-facing second surface having a developed
shape for corrective redistribution of external forces directed
against the area of treatment. The second surface of the adhesive
body is covered by a tough, durable protective layer which may be
either flexible or rigid and may, if desired, be extended to cover
the side edge surfaces of the adhesive body as well.
[0013] Other features, objects and advantages of the invention will
become apparent from the specification and drawings.
DRAWING
[0014] FIG. 1 is a longitudinal sectional view of an adhesive foot
orthotic embodying this invention.
[0015] FIG. 2 is a vertical sectional view taken along line 2-2 of
FIG. 1.
[0016] FIG. 3 is a sectional view taken along line 3-3 of FIG.
1.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
[0017] Referring to the drawings, FIGS. 1-3 depict an adherent
orthotic pad 10 for treatment of a foot 11, and particularly for
protective treatment of a wound 12, such as a pressure ulcer, along
the plantar surface of the foot extending over a bony prominence at
the metatarsal joint. While a foot orthosis is illustrated, it is
to be understood that the invention is not limited to an orthotic
pad for treatment of the foot. The drawings show only one
embodiment of the invention, but other embodiments may include
adherent orthotic pads for treatment areas where dermal and muscle
tissue have developed pressure ulcers such as, for example, the
sacrum, coccyx, elbow, or any other part of the body exposed to
pressure or shear insult resulting from the concentration and
extended duration of external pressures producing circulatory
insufficiencies and tissue death.
[0018] The pad comprises a hydrocolloid-containing adhesive body 13
and a protective outer covering 14. The body is formed entirely of
a soft, deformable, pressure-sensitive, hydrocolloid-containing
adhesive composition, commonly referred to as a skin barrier
composition, that is generally non-flowable, retains its integrity
upon hydration, and has shape-recovering properties. It must be
capable of adhering to the skin for extended periods, but the
adherence must not be so aggressive as to risk skin injury or
irritation during use and at the time of removal. It should also
have sufficiently high cohesive strength to resist disintegration
throughout its duration of use and to remain intact at the time of
removal so that little or no residue remains adhered to the
skin.
[0019] Such adhesive skin barrier compositions are known for use in
ostomy and wound care and typically comprise a discontinuous phase
composed of particles of one or more hydrocolloids dispersed
throughout a continuous water-insoluble elastomeric adhesive phase.
Initial tack, usually referred to as dry tack, is provided by the
continuous phase but, because such a barrier material is occlusive
or non-breathable, adherence to the skin would be disrupted by
perspiration if it were not for the dispersed hydrocolloids which
absorb fluids and thereby maintain and possibly enhance adhesive
attachment to the skin. U.S. Pat. Nos. 5,492,943 and 4,551,490
disclose suitable water-absorbing and swellable hydrocolloid gums
including sodium carboxymethylcellulose, pectin, gelatin, guar gum,
locust bean gum, gum karaya, and mixtures thereof. The elastomers
used in the continuous phase commonly include polyisobutylenes,
which may be either of relatively low viscosity average molecular
weight (about 36,000 to about 58,000) or of higher molecular weight
(for example 750,000 to 2,350,000). The elastomer phase may also
contain a styrene block co-polymer component to help provide
extensibility and recovery from modular strains. While proportions
may vary, such skin barrier compositions generally have a
hydrocolloid content within the range of about 35% to 70% by weight
of the total composition and an elastomeric adhesive phase in the
range of about 20% to 40% of that total. In addition, such a
composition may include hydrocarbon plasticizers consisting of
petrolatum or mineral oil, and suitable tackifying and antioxidant
agents. For more detailed information concerning such skin barrier
compositions, reference may be had to the abovementioned patents,
the disclosures of which are incorporated by reference herein.
[0020] A characteristic aspect of an orthotic pad embodying this
invention lies in the fact that the two major surfaces of the
adhesive body 13 are of different shape or contour and are
non-parallel, resulting in a body of differing thickness or depth
throughout its outline area. A first or body-facing surface 13a is
shaped to match the contour of the body part to which the adhesive
orthotic pad is to be adhered, whereas the second or outwardly
facing surface 13b is of a different shape designed for corrective
redistribution of external forces exertable against the body part.
If the adherent pad takes the form of a foot orthotic as shown,
then the second surface 13b may be substantially planar, matching
that of a floor or other planar support surface upon which the
patient's foot may be placed. However, in the case of a patient
having foot deformities that tend to produce abnormally high
pressure and shear areas when the patient stands and walks, the
outwardly facing surface 13b of the pad may be of developed shaped
to help correct defects in the patient's gait. By redistributing
external forces applied to the foot so that localized areas of
excessive pressure or shear over bony prominences are avoided, the
formation of pressure ulcers in such areas may be prevented and the
healing of ulcers in such areas may be promoted.
[0021] Protective layer 14, also referred to herein as a protective
layer 14, or simply a covering 14, covers the outer surface 13b of
the adhesive layer and matches the shape or contour of that
surface. In a preferred embodiment, the protective layer or cover
also extends upwardly about the side edges or surfaces 13c of the
adhesive layer as shown in the drawings. Covering 14 may be formed
of any tough and durable material capable of withstanding contact
with external objects and surfaces, and the covering can be
flexible or rigid. A tough flexible polymeric film, such as one
formed of a polyolefin, is believed suitable, but other materials,
such as fabrics of natural and synthetic fibers, may be used. The
protective covering layer 14 is of generally uniform thickness
throughout its full extent, but its outwardly-facing surface may be
patterned or textured to prevent slipping and provide traction upon
engagement with a support surface. Preferably, the protective layer
14 is rigid and textured for foot orthotics, and rigid and smooth
for orthotic pads intended for use elsewhere on the body.
[0022] Any of a number of methods may be used to form the foot
orthotic 10 so that its body-facing surface 13 matches the contour
of the full treatment area which the orthotic is to adhesively
engage--in this case, the entire underside of a patient's foot.
Such methods include making a plaster cast of the foot, using that
cast to make a positive mold, and then molding the body of skin
barrier material about one side of the positive mold. Other methods
include using a laser scanner combined with 3D CAD software to
develop a positive mold that duplicates the treatment surface to be
protected and then using that mold to produce an orthotic in which
a surface of the adhesive body matches the surface to which the
orthotic is to be adhered. While the term "matching" is used to
describe the contour of the body-facing surface of the adhesive pad
or device, ordinarily where the body surface to be treated has a
wound with a substantial depression or cavity 12, the surface of
the adhesive pad is formed to span that depression or cavity (as
shown in FIGS. 1 and 2) rather than project into the wound.
[0023] While in the foregoing, an embodiment of the invention has
been disclosed in detail for purposes of illustration, it will be
understood by those skilled in the art that many of these details
may be varied without departing from the spirit and scope of the
invention.
* * * * *