Note: Descriptions are shown in the official language in which they were submitted.
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ACXGROUND OF THE INVENTION
~he present invention relates to orthopedic devices
Ifor supporting body portions and a method of fitting these
1~ devices. ~Sore particularly, the invention relates to inexpen-
'sive, easily formed, removable casts, braces or supports which
provides comfortable patient fitting as well as providing better
support and stability than previously available removable ortho-
pedic supports.
Numerous materials have been used or proposed for
orthopedic casts, splints, and braces. The conventional material j
is Plaster of Paris. Mixtures of Plaster of Paris and water are
¦Iformable and moldable when wet but harden upon drying. Other
materials which have been used for orthopedic supports include
¦ numerous synthetic resins, e.g., plastics. Some of these synthe-
tic materials are soft for shaping and forming until subjected to
a liquid polymer cure while others may cured by subjection to
ultra-violet radiation. ~ large family of synthetic resins are
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thermoplastic; tnat is, they may be heat-softened and harden upon
cooling.
The following United States patents are examples of the
orthopedic device art:
Patent No. Patentee
2 759 475 Van Swaay
2 781 757 Hauser et al.
2,800,129 Van Swaay
3,089,486 Pike
1~ 3,302,642 Allen
3,490,444 Larson
3,501,427 Edenbaum
3,662,057 Webster et al.
3,819,796 Webster et al.
1~ 3,996,219 Mercer et al.
4,Q06,741 Arluck
4,019,505 Wartman
4,226,230 Potts
The materials used for previous orthopedic devices such
as casts, splints, and braces have significant shortcomings. For
example, Plaster of Paris is inconvenient to use because it
undergoes irreversible hardening and hence cannot be reformed.
Casts made with Plaster of Paris are heavy and bulky, yet the
material crumbles readily. Further, supports made of Plaster of
Paris generally cannot be readily removed and replaced. Hence
bathing with a Plaster of Paris cast causes problems because the
plaster deteriorates when wet.
Other materials which have been used to form orthopedic
supports also have physical properties which make them unde-
~0 sirable. For example, mixing of plastics to obtain polymeriza-
tion for proper hardening often requires considerable care and
~lundesirable clean-up. A number of materials are not easily
moldable while others require cumbersome wrappings, e.g., with
l~bandages, thereby prohibiting easy removal for bathing or comfort
3~ 1I purposes.
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So~e previously used materials have additional dif-
ficulties because of insufficient strength, brittleness, dimen-
sional instability, or lack of thermal softening satisfactory for
forming directly on a limb or other body member to be supported.
Many of the thermoplastic materials which have been suggested for
use in orthopedic devices require molding temperatures so high
that bulky, cumbersome thermal padding must be used to prevent
damage to the skin.
Many other materials that are therr,~omoldable at lower
temperatures lose their dimensional stability at too low a tem-
perature to be useful. For example, one currently used brace,
tradenamed WARM'N ~ORM, uses a thermoplastic sandwich such as
disclosed in the Arluck U.S. Patent No. 4,006,741. This thermo-
plastic sandwich can be molded simply by immersing in a hot wate~
1~ bath. This type of heating obviates the potential problem of
blistering skin caused by too high a temperature but this brace has
the problem tha~ if it is left in a car on a hot day, the support
member loses all dimensional stability and has to be remolded to
conform to the body contours. This device also lacks sufficient
~U structural support to properly protect the body portion.
Accordingly, an object of the invention is to provide
an improved orthopedic device for protecting and supporting body
portions such as limbs or torso. Another object of the invention
is to provide an orthopedic device for supporting body portions
2~ which is easily fitted and moldable upon the patient without
danger of injury. A further object of the invention i5 to pro-
vide a process for fitting an orthopedic device to a body portion
¦ ~hich is quick, easy, and requires as little manlpulation of the
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patient as possible. Fitting the device to the body portion in
this manner is more comfortable for the patient and allows braces
or other supports to be fitted and reformed as needed by lab
technicians.
Other specific objects of the invention include the
attainment of an orthopedic splint, brace, cast or like support
that is easy to form, that can be thermoformed directly on the
limb or other body portion to be supported after softening by dry
heat, that can be formed with a relatively high degree of
cleanliness and hence requires little clean-up, that is readily
softened and may be resoftened to improve fit or accomodate
changes in size of the body portion due to swelling, that is
relatively comfortable for the patient to wear because of its
light weight and proper support, that has a relatively high
1~ degree of dimensional stability after forming, that is suf-
ficiently strong to resist crumbling, cracking, abrasion, and
like breakage, that can be formed for relatively .easy temporary
removal and subsequent replacement, and that is highly resistant to
water damage. Materials forming the orthopedic support should be
~U compatible for long term contact with the patient. The orthope-
dic device of the present invention is versatile enough that it
can be used to support almost any body portion, e.g., limbs or
torso, yet is inexpensive and easy to mold.
Other objects and features of the invention will be
apparent from the drawing and the following description.
S~MMARY OF THE INVENTION
This invention is based, in part, on the discovery that
`Certain selected themoformable ;ateFial5 may be molded into a
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support panel having properties which permit construction of an
improved orthopedic device. These materials provide satisfactory
molding properties at elevated temperatures while retaining
excellent strength, rigidity, and resiliency at room temperature.
S When placed in properly designed supporting bel~s, support panels,
formed of these materials produce the improved orthopedic devices
of the invention.
The purpose of the improved orthopedic device is to
protect and support a body portion. The device includes a web
adapted to encircle body portion to be supported and formed of a
resilient, stretchable material. The web has interior and
exterior surfaces, the interior closest to the body portion being
supported. The device also includes a cinch strap adapted for
tightening the device about the body portion and a heat barrier
lj forming a pocket with the interior surface of the web to hold a
structural support panel. ~referably, the heat barrier has an
inner layer which contacts the body portion, a middle layer
forrning a thermal barrier and cushloning pad, and an outer layer
which, together with the web, forms the surfaces of the pocket.
~U Preferable materials include nylon for the inner layer, a
polyether foam for the middle layer, and nylon adapted to
withstand temperatures of up to about 400F for the outer layer.
Most preferably, the three layers of the heat barrier are flame
bonded.
The orthopedic device includes a structural support
panel adapted to fit into the pocket formed by the heat barrier
jand the web. The structural support panel ls formed of a
~material substantially flexible and moldable at forming tem- i
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peratures of between about 220F and 375F while remaining
substantially rigid, resilient and shape retaining at ambient
temperature. Preferred materials for the structural support are
copolymers, blends, grafts, and alloys of acrylates, methacryla-
I tes, polycarbonates, and polyvinyl chlorides, most preferably an
alloy of polyvinyl chloride and polymethylmethacrylate. Optimum
structural support panels have a modulus of elasticity of about
100,000 - 500,000 psi at ambient temperature, and which falls to
about 30-500 psi at forming temperatures. Most preferably, the
1~ structural support panel should be constructed of a material
having a Rockwell R hardness of about 90, a Rockwell L hardness
of about ~5 and a Shore D Durometer hardness of about 75.
The invention also includes a process for fitting an
orthopedice device to a body portion. The process starts by
1~ ; fitting a removable belt about the body portion. The belt is
substantially similar to the orthopedic device as previously
described except without the structural support panel; that is,
~ the belt consists of a web, a cinch strap, and a pocket with a
¦ heat barrier on the inner side. After fitting the removable belt
2U ¦ about the body portion, a thermoformable structural support
¦ panel, having properties previously described, is heated to be-
! tween about 220F and 350F until the panel becomes pliable and
8ubstantially moldable. The heated support panel is then placed
within the pocket of the belt with the belt on the body portion.
~5 IThe resilience or ela8ticity of the belt starts molding the support
¦panel and pressure is applied to the exterior of the belt to
¦enhance molding the support panel to conform to the body portion.
The support panel is allowed to cool in place until the panel is
rigid, resilient, and 8hape-retaining. Preferably, manual pressure
~ is used to mold the support panel.
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The process of the invention permits simple, quick,
;safe and reliable forming of the orthopedic support on a body
portion. The discomfort normally experienced by a patient in
fitting a brace is alleviated; in fact, the patient will normally
feel a slight soothing warmth as the device is being molded. The
¦ device is readily removable which allows the patient to bathe or
;wash the body portion thereby promoting patient comfort. The
support panel can be remolded in a very short time, e.g., about 5
I minutes, which allows the device to be used to accomodate changes
in size of the body pGrtion, e.g., due to swelling, and permits
ease of remolding the brace to the body portion for optimum
patient comfort.
The fol]owing description and the drawing will further
illustrate the efficacy of the invention.
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3RIEF DESCRIPTION OF THE DR~WING
For a fuller understanding of the nature and objects of
I the invention, reference is made to the following detailed
¦Idescription and the accompanying drawing, in which:
~, FIGURE 1 is an illustration of an orthopedice device
¦ within the scope of the invention, specifically a lumbosacral
¦back brace;
¦ FIGURE 2 illustrates the interior surface of the back
Ibrace of FIGURE l;
¦ FIGURE 3 illustrates the exterior surface of the back
2~ ¦ brace of FIGURE 1~
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FIGU~E 4 shows a cutaway view of the pocket section of
the brace illustrated in FIGURE 1 with a support panel in place,
particularly illustrating the layers of the preferred heat
barrier:
FIGURE 5 illustrates a blank for molding into a struc-
tural suppor~ panel;
FIGURE 6 illustrates a side view of the blank
ilLustrated in FIGURE 5;
FIGURE 7 illustratas a structural support panel for a
i back brace as molded fro~ the blank of FIGURES 5 and 6; and
j FIGURE 8 illustrates a back view of the structural
j support panel of FIGURE 7.
DESCRIPTION OF ILLUSTRATED EMBODIMENT
, The present invention features an orthopedic device and
1~ a process for fitting the orthopedic device to a body portion.
I Depending on the support requirements of the body portion
¦¦ encircled by the orthopedic device, the size of the structural
support panel and, accordingly, the shape and size of the thermal
barrier varies. For example, if the orthopedic device is to be
~U 1 used to support a limb, the structural support should almost
completely encircle the limb, only having an opening sufficient
that the support may be removed for bathing or examination. If,
I however, the orthopedic device is used as a support for the bac~
¦ the structural support panel does not need to ençircle the body
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As previously noted, a number of different materials
can be used for the structural support panel. These materials
include alloys, grafts, blends, and copolymers of polycarbonates,
acrylates, methacrylates, and polyvinyl chlorides. The major
I requirements for materials forming the structural support panel
are durability, scuff resistence, rigidity, resilience and shape-
; retaining properties at ambient temperature while being thermo-
moldable and substantially flexible at elevated temperatures.
The support material is, moreover, to retain its perimeter shape
1 at the elevated molding (fitting) temperature. Thermoplastic
resins having a modulus of elasticity of about 100,000 - 500,000
psi at room temperature of requirements and a modulus of elasti-
city of 30 - 500 psi at forming temperatures of about 220F to
375F fulfill other materials requirements. Preferably,
; materials used for the structural support have a Rockwell R hard-
ness of about 90, a Rockwell L hardness of about 45 and Shore D
Durometer hardness of about 75. The structural support material
should be thermoformable at temperatures of not less than about
1 220F but not more than about 375F. lf the material has
2~ ~ substantial moldabiliey at temperatures less than 220~, it may
not not hold its shape if placed in hot areas, e.g., a car trunk,
while if the material requires a much higher temperature for
moldability, the danger of burning the patient or the person
molding the brace is great. One material which has been used
¦ successfully for the structural support panel is an alloy of
polymethylmethacrylate and polyvinyl chloride produced by Rohm
and Haas called ~YDEX. This material, the exact formulation of
which is kept a trade secret by Rohm and Hass, is believed to be
a true solution of polyvinyl chloride and polymethylmethacrylate.
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Attached hereto as Appendix I is a copy of a product specification
! brochure for the Kydex material. The Kydex polymer has a Shore D
Durometer hardness of 77, a ~ockwell R hardness of 90 and a
Rockwell L hardness of 45. Its modulus of elasticity at room tem-
j perature is about 330,000 psi while at 350F, the modulus of
elasticity drops to about B0 psi. Kydex also has a tensile yield
of about 6~00 psi on the D-638 scale and is substantially scuff
resistent. While the Xydex polymer appears to be an excellent
; material for the structural support, those skilled in the art will
~ be able to determine other materials which also are well suited.
The following illustrated embodiment further explains
the invention and its efficacy. This embodiment is a lumbosacral
brace to support the back, particularly at the S-l, S-~ and L-4,
L-S area.
lS Turning to the drawing, FIGURE 1 illustrates a lum-
bosacral brace in a closed position as if encircling a body. The
, brace has four major portions: a web 10 formed of a resilient,
elastic material such as conventional three panel elastic, a
!~ cinch strap 12 formed, preferably, of a non-stretchable material,
2U ~ a heat barrier 14 which together with web 10 forms a pocket 16
jl and a structural support panel 30 formed of a material like
¦; kydex. Support panel 30 is shown in Figure 1 only as cross-
¦ hatching since it would not be seen from this perspective. The
other figures further illustrate this brace and its parts.
2~ I A description of the process for fitting a brace about
a body portion, e.g., the lumbosacral region, further illustrates ¦
I the invention. The body is first encircled by the orthopedic
¦ device without structural support panel 30 in place. FIGURE 2
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illustrates the interior portion of t~e belt section of the
device, that which is placed closest to the body, while FIGURE 3
shows the exterior. Heat barrier 14, which forms pocket 16 with
web 10, is placed against the body section to be supported and
web 10 encircles the front of the pa~ient with the left portion
closing first. Web 10 is fitted in place by adjustable closing
devices 18 and 18', preferably Velcro brand hook and loop
l,fastening device strips, on the two side panels of web 10. Once
j a rough adjustment is made with closing devices 18 and 18', cinch
~belt 12 is tightened about web 10. Cinch strap 12 has its own
two-part adjustable closing device, again preferably Velco,
designated 20 and 26, which is used to obtain a rough approxima-
tion of the final fit. The actual tightening is done by passing
I cinch strap 12 through buckle 24 to achieve proper tightening.
I~Once the proper adjustment of cinch strap 12 through buckle 24
has been made, all opening and closing of cinch strap 12 is
carried out using Velcro closing device 20 and 26.
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l~hile the belt portion of the orthopedic device is
llbeing fitted, structural support panel 30 can be heated to
I!molding temperature. One procedure which has been used success-
¦ fully consists of placing a blank or preformed panel 30 such as
¦is illustrated in FIGURES 5 and 6 on a dry heat device, e.g., a
¦hot plate or warming tray, until flexible, approximately 5-10
minutes. At molding temperatures of 220F-375F, structueal sup- ¦
~,5 ,port panel 30 i8 quite flexible; a mitten or glove is typically
~used for handling of this temperature. Structural support panel 3
i8 placed in pocket 16 formed by heat barrier 14 and web 10 and th~
device i~ quickly placed about the patient's body in proper posi-
tion. Cinch 12 is tightened and locked about the patient with
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Velcro closing device ~0 and 26. Tighteniny the device about the
patient starts the molding process; that is, the elastic of the web
partially molds the support panel to the body portion. The warm
and moldable structural support panel 30 is normally hand molded to
S enhance the conforming of the brace to the shape of the body por-
tion. Once structural support panel 30 is cool, normally a period
of about 5 minutes, structural support panel 30 is rigid, with
stiff resilience and shape-retaining. FIGURES 7 and 8 illustrate a
structural support panel 30' which has been molded to conform to
j the lumbosacral section of a back. During the fitting process for
this type of brace, the patient has a minimum of discomfort and
normally feels a slight warmth which is pleasant and soothing.
I After the molding process is finished, the brace is ready to wear.
~ EIGU~E 4 illustrates the heat barrier and pocket of the
1 orthopedic device. Preferably, the heat barrier consists of
three layers: an inner layer 32, a middle layer 34 formed of an
insulating material which acts as a thermal barrier, and an outer
layer 36 which forms one surface of pocket 16. Inner layer 32 is
l preferably made of nylon, e.g., a nylon tricot, and is placed
l,next to the patient's skin or clothing. Middle layer 34 can be
I any insulating material but preferably is a thin (e.g., less than
i l/B inch thick) cushioning foam such as conventional polyether
¦ifoam which has sufficient thermally insulating properties to
¦¦allow the device to be placed directly against the patient's skin
lafter the heated structural support panel is placed within pocket
¦16. Inner layer 36 must be relatively heat resistent since it
18 in direct contact with heated structural support panel 30.
l Preferably, outer surface 36 is a nylon which can withstand tem-
r ~ t e of 408-~. FI ~ ~ how structur~l .uppo
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panel 30 is placed between outer layer 36 and web 10 in pocket
16. Panel 30 is illustrated with several ventilation holes 40
which permit air cooling while patient wears the brace.
Normally, pocket 16 is sewn on three sides as illustrated in
~IG~RES 2 and 3 witn only the top open, but another orientation
I of pocket 16 which will allow easy insertion of structural sup-
! port panel 30 may be employed. The exact choice of materials for
the belt is within the knowledge of those skilled in the art.
i3elts fitting these specifications may be manufactured by various
lV ; venders; in fact, belts for a commercial version of the present
invention, tradenamed ORTIIO-MOL ~ are available from Brunswick
Medical of Boston, Massachusetts.
The orthopedic device disclosed herein allows quick,
easy fitting with maximum comfort to the patient and maximum sup- i
port while being removable, easily remoldable and easlly
cleanable. The orthopedic device of the present invention yields
superior patient comfort and is reasonable in cost to form and
fabricate. It is thus ~een that the objects set forth above are
efficiently attained by the disclosed invention.
~V 1I The process and device of the invention can be modified
in ways obvious to those skilled in the art. Accordingly, the
invention includes such modifications and variations.
I ~hat is cl;ined is:
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