Note: Descriptions are shown in the official language in which they were submitted.
CA 02478162 2004-08-20
1
ORTHOPEDIC BRACES AND CASTS WITH
AERATING ARRANGEMENTS
This invention relates to braces for supporting and putting pressure on
a person's or animals' body part, venting devices for use with orthopedic
casts or braces, and supporting and ventilating devices for a walking cast.
In order to treat certain injuries in the lower extremities of a human's or
animal's body, such as a bone fracture or severe sprain, it is known to
immobilize the region of the injured body part completely by the use of a
molded plaster or resin cast. However, once the injured body part has begun
to heal and has stabilized, it is known that a more rapid recovery can
sometimes be obtained by gradually and progressively permitting the injured
body part to bear some weight and to undergo some exercise. In the latter
stage of recovery, an orthopedic brace may be used.
In one such known brace, there is a shaped rigid outer shell on the
inside of which is provided an inflatable liner or air cell to engage and to
apply
pressure to the body part or limb. For example, in the brace of U.S. Patent
No. 5,577,998 issued November 26, 1996 to Aircast, Inc., the brace includes
a rear outer shell member having a vertical portion that extends up the lower
part of the user's leg and a horizontal portion that extends under the foot, a
frontal outer shell member that covers the front of the lower leg and the top
of
the foot, and air cells disposed within a liner of the brace. Flexible straps
are
used to secure the rear and frontal shell members securely about the lower
leg and foot. Using a brace of this type, the ankle and leg are sufficiently
supported that the wearer of the brace can walk. Because the wearer is able
to walk and carry out certain allowed exercises, this can lead to a more rapid
complete healing of the injured part than would be the case if such a brace
were not used.
A common and well known problem with the use of rigid casts made of
plaster or fiberglass is the lack of ventilation to the skin area under the
cast
and this can also be a problem with a brace, particularly when the liner of
the
brace is not constructed in a fashion to provide adequate air ventilation. A
lack of air to the skin area can cause discomfort and irritation to the
patient. A
variety of different structures and methods have been proposed in the past for
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providing air ventilation to the skin under a cast. It is known, for example,
to
provide cast venting devices in the form of a woven fabric with an elongate
tube or similar air passageway in contact with the skin and over which the
6 plaster of paris mix or fiberglass casting material can be placed to form
the
cast. Also, it is known to provide a device for forcing air under the cast,
one
such device being an air pump equipped with a suitable delivery mechanism.
In my co-pending Canadian patent application No. 2,467,154 filed May
12, 2004, there is described an improved cast venting device that may
comprise either two elongate strips or two layers of flexible material, at
least
12 one of these layers being porous. The strips or layers are spaced apart
from
each other and are parallel. Flexible spacer members are arranged between
the strips or layers and connect them together and these members form air
passageways between the adjacent spacers. A preferred material for the
inner porous layer or both layers is ethyl vinyl acetate (EVA), this material
having numerous small holes distributed evenly over its surfaces.
18 There is described herein a brace for providing therapeutic pressure to
a person's or animal's body part, this brace including both a rigid exterior
shell
and an interior liner which provides air passageways to allow air circulation.
Thus, this brace may be more comfortable for a user to wear, particularly for
an extended period of time.
There is also described herein a venting device for use with a cast or
24 brace which is made of two half sections that can be combined to enclose
the
body part. This venting device includes two spaced apart inner and outer
layers of flexible, resilient material and spacer members arranged between
and connecting the two layers. Air passageways are formed between the
spacer members.
There is further described herein a supporting and ventilating device
30 for a walking cast that includes a base plate formed with air passageways
formed in its top surface and these passageways can allow air to flow through
a porous sole layer adapted to cover the base plate.
According to one aspect of the invention, a walking brace for providing
therapeutic pressure to a person's lower leg includes a rigid exterior shell
adapted to fit around at least a major portion of the lower leg
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and having interior and exterior surfaces and two opposite sides. The shell is
perforated over a substantial portion of each of the interior and exterior
surfaces so as to allow air to pass through the shell between the surfaces. An
6 interior resilient liner is arranged in the shell to cushion the major
portion of
the lower leg. The liner includes two spaced-apart inner and outer layers of
flexible material that extend substantially parallel to each other and spacer
members arranged between and connecting the inner and outer layers. At
least the inner layer is porous so as to allow air to pass through the inner
layer. The spacer members form air passageways between adjacent spacer
12 members so that air can pass along the passageways to allow air circulation
in the liner and through the inner layer during use of the brace. The brace
includes at least one connector for securing the brace to the lower leg and a
strap bridge for each strap connector, which is mounted on the exterior shell.
Preferably at least the inner layer of the liner is elastomeric, is made of
ethyl vinyl acetate (EVA), and has numerous holes distributed evenly over
18 inner and outer surfaces thereof and extending through the inner layer.
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Further features and advantages of the present braces will
become apparent from the following detailed description of
preferred embodiments taken in conjunction with the accompanying
drawings.
6 In the drawings,
Figure 1 is a perspective view showing the front and left
sides of a walking brace constructed according to the invention;
Figure 2 is a partially exploded perspective view of the
walking brace of Figure 1, this view showing a rigid sole member
and a perforated top sole separated from bottom layers of the
12 brace and omitting the frontal section of the brace;
Figure 3 is a perspective view similar to Figure 2 but with a
layer of an inner liner removed to illustrate underlying support
structure, this view omitting 30 the rigid sole member and the top
sole;
Figure 4 is a perspective view of the frontal shell that can be
18 used with the walking brace apparatus of Figures 1 and 2;
CA 02478162 2004-08-20
Figure 5 is a perspective view showing the front and left sides of a
second embodiment of walking brace, its frontal shell also being omitted for
sake of illustration;
5 Figure 6 is an isometric, exploded view showing a small portion of
individual components of a preferred venting device;
Figure 7 is an isometric view showing the venting device of Figure 6
with the components assembled and connected;
Figure 8 is an isometric exploded view showing a small portion of
components for an alternative form of venting device;
Figure 9 is a perspective view of a bottom section of a walking brace of
the invention, this view showing a detachable foot piece partly removed from
a bottom section of the brace;
Figure 10 is a perspective view showing the front and right sides of a
venting device for an orthopedic cast, this device being shaped to fit around
the foot and ankle of a patient;
Figure 11 is a vertical cross-section of a venting device extending
around a patient's foot and ankle, with a rigid cast extending around the
venting device;
Figure 12 is a vertical cross-section taken along the line Xll-XII of
Figure 11 and showing the patient's five toes surrounded by the venting
device;
Figure 13 is a vertical cross-section of a walking cast using a
supporting and ventilating device constructed according to another aspect of
the invention;
Figure 14 is another vertical cross-section of a walking cast wherein
the front of the foot is covered by the cast;
Figure 15 is a transverse vertical cross-section of the walking cast, this
view being taken along the line XV-XV of Figure 14;
Figure 16 is a perspective view showing the top, front and right sides of
a venting device for a cast, this device being fitted around a person's elbow
in
a bent position;
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Figure 17 is a perspective view showing the top and front end of
another version of a venting device for a cast, this version being fitted
around
a person's wrist area; and
Figure 18 is a side view of an air cell and hose connector that can be
used in the walking brace of Figures 1 to'3.
A preferred form of walking brace 10 for providing therapeutic pressure
to a person's body part, namely a lower portion of a person's leg, is shown in
Figure 1. It will be appreciated that although a walking brace is illustrated,
it is
also possible to employ a brace constructed in accordance with the invention
which is not a walking brace but is adapted for use on a body part other than
the lower leg. Also although the illustrated walking brace 10 is adapted for
use
on the lower leg of a person, it will be appreciated by those skilled in the
art
that a brace constructed in accordance with the invention can also be used on
an animal's body part.
The brace 10 includes a rigid exterior shell indicated generally by
reference 12, this shell being adapted to fit around at least a major portion
of
the body part, in this case, the lower portion of a person's leg, including
his or
her foot, and has an interior surface 14 (visible in Figure 3) and an exterior
surface 16. The preferred exterior shell includes a rigid front shell section
18
adapted to cover a frontal area of the lower leg and a top surface of the foot
of a person. This front shell section is detachably secured to a rear shell
section 20 shown by itself in Figure 2. This rear shell section forms the
remainder of the exterior shell 12. As shown in Figures 1 to 3, the exterior
shell, including both the front and rear shell sections 18 and 20, are
perforated over a substantial portion of each of the interior and exterior
surfaces 14 and 16 so as to allow air to pass through each shell section
between these surfaces. These perforations are indicated at 22. Both the
front and rear shell sections can be made either from a suitably rigid and
tough plastic that can be molded to have the desired perforations or can be
made of a suitably strong metal such as aluminum or stainless steel. In either
case, the thickness of the shell should be sufficient to provide the required
rigidity so that the walls of each shell section will not bend to any
significant
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7
extent. In other words, each shell section is made sufficiently rigid so that
the
overall exterior shell can serve its function as a brace that will support the
enclosed body part and not permit undesirable movement thereof. The edge
section 24 of the rear shell section 20 can be made as a solid plastic or
metal
strip that is smoothed and rounded so as not to provide a hazard to the user.
6 Similarly, the front shell section 18 can have solid edge strips 26 provided
along curved right and left edges and top and bottom solid edge strips 28 and
30.
The walking brace 10 also includes an interior resilient liner 32
arranged in the exterior shell 12 to cushion the body part. The liner 32 is
perforated with numerous small passageways 34 over at least a substantial
12 portion thereof so as to allow air to pass readily between the inner
surface 36
of the liner and its exterior surface. In the illustrated embodiment, all of
the
inner surface of the liner is perforated in this manner.
The front shell section 18 can have its inner surface covered with a
single layer of the resilient liner material. Also, an upper portion 38
extending
to the top of the walking brace and a front portion 40 of the rear shell
section
18 20 can be covered with a single layer of the liner material. This material
can
be about 1/8th inch thick and preferably is elastomeric in nature. One
preferred material for this liner is ethyl vinyl acetate (EVA) formed with
numerous holes distributed evenly over inner and outer surfaces thereof and
extending through the layer. Thus, except for a central portion of this brace
(see below), air is able to pass freely through both the perforated outer
shell
24 12 and then through the liner 32. This type of perforated liner is believed
to be
an improvement over the liner used in the walking brace of U.S. Patent No.
5,577,998, for example. A difficulty with known liners is that they are made
of
a soft material which will compress substantially when compressed (as is
normal when they are used under a brace). This squeezing and compression
of the liner can prevent or substantially reduce any air circulation through
the
30 liner. The preferred EVA material is stronger, more sturdy, and less likely
to
collapse in a way that prevents air circulation.
Preferably the walking brace is provided with one or more inflatable,
plastic liners or air cells described below. These air cells 42 are located in
a
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8
central or ankle portion 44 of the brace. The area covered by one of these air
cells is indicated in part by the dash line 43 in Figure :3 The air cells can
be
constructed as illustrated and described in U.S. Patent No. 5,577,998 issued
November 26, 1996 to Aircast, Inc. Figure 18 illustrates one side of such an
air cell 42. It may or may not contain resilient foam as described in that
6 patent. There can be one of these air cells provided on each side of the
rear
shell section 20 for a total of two of these air cells or there can be a
single air
cell only which can extend along both sides and the back of the patient's
ankle. It will be understood that with the use of these air cells, the
therapeutic
pressure that is applied to the body part can be adjusted, as desired.
However, each air cell 42 is made of an imperforate, flexible plastic material
12 that does not allow air to flow from the outer surface of the air cell to
the inner
surface. Each air cell is made of two sheets of flexible plastic sealed around
their perimeter and can have a flexible hose connector 51 extending from the
cell to the exterior of the shell. The connector 51 terminates in a closable
port
53 and links the interior of the cell to atmosphere. The connector is made of
flexible plastic tubing. A closeable sealing device is provided at the port 53
to
18 trap air in the cell.
The present walking brace 10 is provided with a liner section in the
region of these air cells which is able to provide adequate air circulation to
the
central portion of the brace. In particular, in this region, the liner has
two,
spaced-apart layers of flexible material, including an inner layer 46 and an
outer layer 48, which can be seen clearly in Figure 3. These layers extend
24 substantially parallel to each other in a non-stressed state, for example,
when
the brace is not being used-and there is no pressure being, applied to the
inner surface of the liner by a person's lower leg, including his or her
ankle.
Because these layers are preferably made of a flexible, elastomeric material,
they will of course bend and distort to some extent when the brace is being
used in order to conform to and match the contour of the person's lower leg,
30 ankle and foot. The liner in the central portion of the brace also includes
spacer members 50 which are most clearly visible in Figure 3. These
members 50 are arranged between and connect the inner and outer layers
and they form air passageways 52 between adjacent spacer members so that
CA 02478162 2004-08-20
9
air can pass along said passageways to allow air circulation in and through
this central portion of the liner during use of the brace. The spacer members
can take a wide variety of forms and are not limited to the versions
illustrated
in the drawings. For example, a variety of suitable spacers are illustrated
and
described in the applicant's co-pending Canadian patent application No.
6 2,467,154 filed May 12, 2004.
With reference now to Figures 6 to 8 of the drawings, there is shown
therein two different versions of liner construction for the central portion
of the
brace, both of these versions employing the aforementioned inner and outer
layers, with at least the inner layer 46 being porous. Although the outer
layer
48 could also be porous, it is preferably imperforate in the region of the air
cell
12 42 which itself is imperforate. In this way the circulating air in this
section of
the liner is directed through the inner layer 46. In one preferred embodiment
of the two layer liner, the layers are approximately 118th inch apart. As
indicated, the preferred material for the inner layer 46 is EVA and this
material
can also be used for the outer layer 48, if desired. Another porous,
elastomeric material that can be used for at least the inner layer 46 is sold
18 under the trade-mark NyplexTMIn the embodiment of Figures 6 and 7, the
spacer members between
the layers are elongate, parallel spacer members 50' that are spaced equal
distances apart as shown. These members 50' can extend from one side
edge of the rear shell section 20 to the opposite side edge and the air
passageways 52' formed between the spacer members can be open ended at .
24 both ends to allow maximum air circulation. Generally, the number of spacer
members provided should be. such as to prevent collapse of the air
passageways formed between them during use of the venting device.
Although it is possible that the air passageways 52' can be open ended at
only one side of the brace, it is preferable for both ends of these
passageways to be open.
30 In the variation of the venting device shown in Figure 8, the spacer
members 60 comprise a plurality of relatively small blocks (preferably solid)
arranged in a plurality of parallel longitudinal rows. The preferred blocks
have
flat top sides 62 and flat bottoms 64 making them easier to bond to the
i.
CA 02478162 2004-08-20
adjacent layers by means of a suitable adhesive. An advantage of using
these small blocks 60 as spacer members is that the air gaps 66 formed
between the blocks in each row permit air circulation in the direction
perpendicular to the length of the blocks. Also, by using these blocks , the
ability of the venting device to bend in order to conform to the interior of
the
6 shell 12 can be enhanced. It will be understood that the spacer members 50,
50' and 60 can be constructed from a variety of flexible materials, including
flexible plastics. In one preferred embodiment, the spacer members are also
made of ethyl vinyl acetate (EVA) so that they will bend and stretch in the
same manner as the inner and outer layers 46, 48 (assuming the latter are
made of the same material).
12 A variety of "EVA" type products are available and can be used in the
construction of the double layer venting device in the brace. These include
Volara 4ETM, AliplastTM (both of 23 durometer), P-CelHTM (20 durometer for
diabetics), and Microcell PuffTM (25 durometer). Another suitable, flexible
material for this venting purpose is Poronh"', a medical 4708 urethane
polymer.
18 Turning now to the construction of the bottom of the walking brace 10,
the user's sole is supported by a rigid base plate adapted for mounting in the
walking cast and shaped and sized to support firmly and comfortably at least
a major portion of a sole of the user's foot. This brace plate can be made of
a
variety of substantially rigid supporting materials, including cork and a
strong
plastic. As shown clearly in Figure 2, the preferred plate 65 has a network of
24 open topped air passageways 66 formed in its top surface 68. The base plate
also has aperture means for allowing air-to flow into and out of these air
passageways when the base plate is mounted in the walking cast. The
illustrated aperture means comprises several apertures 70 formed in the front
ends of lengthwise extending passageways 66. The base plate 65 is also
referred to herein as a rigid sole member.
30 The walking brace is also provided with an inner, flexible sole layer 72
covering the rigid sole member 65. This sole layer which can also be made of
EVA, if desired, is perforated with numerous small air holes 74 to permit air
to
flow between the air passageways 66 and a top surface 76 of the sole layer.
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11
The sole layer 72 should be sufficiently strong and rigid to bridge over
the air passageways 66 while at the same time being sufficiently flexible and
elastomeric to provide a comfortable surface for the sole of the user's foot.
It
should also have sufficient strength that it is not pushed down into the
passageways 66 by the weight of the user's foot in a manner which would
6 block the air flow through the passageways 66.
The bottom surface 80 of the base plate 65 can be rounded to form a
convex curve from toe to heel as shown or it can be flat. In any event, its
shape must match that of an adjacent surface 82 of a further support layer 84
on top of which the base plate 65 can be mounted. The layer 84 can be made
of a suitable, wear resistant plastic or rubber material which optionally can
be
12 reinforced, if desired. In a particular preferred embodiment of the walking
brace, there is a detachable foot piece 86 which can be made of a tough,
elastomeric material and which is mounted on the foot section of the brace,
for example, on the bottom of the support layer 84. This foot piece 86
preferably has a bottom surface 88 which is adapted to engage the ground
during use of the brace, for example, by having a plurality of gripping ribs
or
18 ridges 90 formed thereon. The detachable nature of the foot piece 86 is
illustrated in Figure 9 wherein the foot piece has been partially removed from
the bottom of the foot'brace by transverse, sliding movement. Although the
foot piece 86 can be detachably connected to the brace in a variety of ways,
the illustrated foot piece has a number of parallel, transverse connectors 92
formed integrally on the top surface. These slide into and out of respective
24 grooves 94 formed along the bottom of the support layer 84 and constructed
to capture the connectors 92,-,which can have a rounded transverse cross-
section. In order to maintain the foot piece 86 in its normal position for
use, a
friction fit can be provided between the connectors 92 and the surface of the
grooves 94. Alternatively, a mechanical connector, such as a locking pin or
one or more short screws can be used to hold the foot piece 86 securely in
30 place. A particular advantage of having a detachable foot piece of this
type is
that, when it is not required, for example for sleeping or resting, the foot
piece
can be removed by the patient to make the walking brace lighter and more
comfortable for such purposes. Of course, it will be understood by those
CA 02478162 2004-08-20
12
skilled in the art that it is not necessary to have a detachable foot piece 86
and, for example, the bottom layer of the walking brace can be simply the
support layer 84 made with a suitable bottom surface.
The walking brace 10 of Figure 1 is also provided with two, three or
more connectors for securing the brace on the body part. Shown in Figure 1
6 are two preferred VelcroTM type strap connectors 96 and 98. These strap
connectors can be similar to or the same as those illustrated and described in
the aforementioned U.S. Patent No. 5,577,998. Each strap connector is
provided with a strong, plastic buckle 100 at one end. Provided on one side of
the strap along an elongate section 102 are numerous fiber loops forming the
loop portion of the Velcro fastener. An end section 104 of each strap is
12 covered on one side with numerous small plastic hooks forming the hook
portion of the Velcro fastener. These small hooks can be formed on the same
side of the strap as the loops on the strap section 102. It will be understood
that each strap can be secured in the usual fashion to hold the front shell
section 18 in place and to apply pressure to the leg or foot by inserting an
end
106 of the strap through a hole formed in its respective buckle 100 and then
18 pulling the strap tight by pulling the end section 104 back along the
section
102 and attaching the hooks to the loops. Although only two strap connectors
are shown in Figure 1, it will be understood that a third strap connector can
be
provided on the foot section 110 of the brace. This strap connector can be
constructed in a similar manner to the strap connectors 96 and 98 (except
that it is divided into separate buckle and VelcroTM sections) and operates in
a
24 similar fashion to press the horizontally extending portion of the front
shell
section against the top of the. user's foot Also, although not visible in the
drawings, each strap connector can be held in place by one or two suitable
pin connectors which connect the respective strap or strap section to the rear
shell section 20. In the case of the two upper strap connectors 96, 98, a
single pin connection can be provided for each in the centre of the back of
the
30 shell section.
In order to prevent the strap connectors (which can be quite wide) from
interfering with the air circulation through the exterior shell, strap bridges
can
be provided as shown in Figures 1 to 3. The rear shell section 20 can have
CA 02478162 2004-08-20
13
two, curved plastic bridges 112 and 114 that extend completely around the
two sides and back of this shelf section. Each bridge can be formed with
outwardly projecting edge flanges 116 and 118 that help to hold the
respective strap in place as and when it is secured around the exterior shell.
Each bridge is supported at spaced apart locations to elevate its inner
surface
6 above the exterior surface of the rear shell section. In particular, bridge
supports 120 and 122 are provided at opposite ends of each of these bridges
and connect the bridge span to each front edge section of the rear shell. It
will
be understood that one or more additional bridge supports can be provided
along the length of each bridge between the end supports 120 and 122. No
bridge need be provided in the foot section of the rear shell section 20 since
12 each of the two sections of the strap (not shown) for the foot section can
simply be connected to the top edge section of the rear shell in this region.
Also, there can be provided three bridge sections 125 to 127 on the
front shell section 18. Again, the span of each of these bridge sections is
spaced from the front, perforated surface of the front shell section. This gap
can be seen clearly at 128 below the bridge section 127 in Figure 1. Again,
18 the span of each bridge section is supported in an elevated position by
bridge
supports 130 and 132 located on opposite ends of the span. Preferably the
bridge sections 125 to 127 can be provided with edge flanges 134 and 136 to
help maintain the secured strap connector in place on the bridge section.
Turning now to Figure 5, there is illustrated therein an alternative form
of walking brace indicated generally at 160. This walking brace can be
24 constructed in a similar manner to walking brace 10 of Figure 1, except for
the
differences noted hereinafter.. It will be appreciated that, although not
shown
in Figure 5, this walking brace is also equipped with three or more strap
connectors similar to those shown in Figure 1 to secure the brace on the
lower leg and foot of a patient. A primary difference between the brace 160
and the brace 10 of Figure 1 is that this brace has a lower leg section 162
and
30 a foot section 164 which are pivotably connected to one another by two
pivot
joints 166 and 168. The lower leg section, which in use extends generally
vertically, is adapted to cover at least a portion of a person's lower leg
above
his or her ankle. A major portion of the person's foot rests on the sole layer
72
CA 02478162 2004-08-20
14
of the foot section. In the illustrated brace 160 there is an open area 170
located at the rear of the user's ankle and extending between the two pivot
joints. It will be understood that pivot joints 166, 168, of the type
illustrated are
per se known in the walking brace art and according a detailed description
herein is believed unnecessary. The purpose of these pivot joints is to permit
6 the operating angle of the foot section (as defined by the top of layer 72)
to be
adjusted by the medical personnel relative to the generally vertical position
of
the lower leg section 162. For example, in the case of some injuries, it may
be
necessary for the patient's foot to initially extend at a downward angle to
the
normal horizontal position and the brace 160 can be set at a position which
permits this. Once the brace has been set in the required position, a known
12 securing mechanism is provided that prevents further pivotal movement at
the
joints 166, 168. Later, after the injury has had some time to heel, the
relative
angle of the foot section can be adjusted again by the doctor or other medical
practitioner. In such case, the foot section can be pivoted to a position that
will bring the user's foot closer to or to the normal horizontal position.
It will be further understood that the walking brace 160 is not equipped
18 with any air cells 42 in the ankle region of the brace. Accordingly, the
liner 32'
in this embodiment can comprise a single layer of flexible, porous material,
such as perforated EVA. In this case, the liner 32' comprises at least two
separate sections, including an upper section 172 covering the inside surface
of the lower leg section 162 and a lower section 174 which can include a strip
around the back of the heel.
24 Figures 10 to 12 illustrate a venting device 180 constructed according
to another aspect of the invention. This venting device can be used with an
orthopedic cast or brace, including a walking brace. The venting device
comprises two half sections 182 and 184 which form a complete venting
device when combined together to enclose a person's or animal's body part.
In Figures 10 to 12, the illustrated body part is a person's ankle, including
at
30 least most of the person's foot. Each half section has a length extending
from
one end 186 thereof to an opposite end 188 thereof,and a width W (indicated
in Figure 12) which can vary. Each half section is preformed, for example, by
a heating and shaping procedure, so as to fit closely around a respective
CA 02478162 2004-08-20
curved side of a particular body part, for example, the curve side 190 of the
lower leg.
Each half section comprises two spaced-apart layers of flexible
resilient material that extend substantially parallel to each other. Thus,
there
is an inner layer 192 and an outer layer 194. The resilient material of at
least
6 the inner layer 192 is porous although it is possible for both layers to be
porous as illustrated in Figure 10. As in the venting devices illustrated in
Figures 6 to 8, the venting device 180 also has spacer members indicated at
196 arranged between and connecting the two layers 192 and 194. The
spacer members form numerous air passageways 200 between adjacent
spacer members so that air is free to pass along these passageways from
12 one or more open ends of the passageways located at at least one of the two
ends of the respective half section. In the venting device 180 of Figure 10,
these passageways are open at both the end 186 and the opposite end 188,
thereby allowing good air circulation.
Figure 11 illustrates a variation of the venting device 180 covered by a
rigid plaster or fiberglass cast 202. The venting device 180 of Figure 11
differs
18 from that shown in Figurel0 in that the device covers the toes of the foot
(a
version used if the cast itself covers the toes). The cast can either be
formed
as shown in solid lines so as not to cover the toes of the patient or it can
be
extended as indicated by dash line 204 to cover the toes of the patient. In
the
latter case, unless provision is made for forming openings in the cast; then
the passageways formed by the venting device 180 are open only at upper
24 end 186. Also, it will be understood that when this venting device 180 is
used,
the two half sections 182, 184 are placed around the selected body part so
that they meet along respective lengthwise extending edges 206 and 208 and
surround the body part. Once the venting device is in place, the cast or brace
is applied over the venting device as shown in Figures 11 and 12 so that the
venting device is pressed against the body part and the cast or brace.
30 In the illustrated preferred embodiment of this venting device, each half
section 182, 184 is substantially U-shaped in widthwise cross-section (as can
be seen clearly in Figure 12), although the shape of the U can vary
substantially depending upon the section of body being covered. It will also
be
CA 02478162 2004-08-20
16
seen that each half section 182, 184 is bent at 210 in the lengthwise
direction,
for example, in the region of the ankle. It will be appreciated that this
particular form of venting device is particularly useful where a venting
device
is required that extends around a bent body part such as an ankle or elbow.
Figure 16 illustrates another venting device formed and sized to fit
6 around a patient's elbow connecting upper arm section 213 to forearm 215.
As in the venting device of Figure 10, the venting device 212 also comprises
two half sections 216 and 218 which join along lengthwise extending edges
located at 220.
Figure 17 illustrates another embodiment of venting device 222 which
is shaped and sized to fit the curved surface of the wrist region formed
12 between forearm 224 and fingers 226. Again, this venting device 222 is
constructed in a manner similar to the venting devices 180 and 212 and
comprises two half sections 228 and 230 that are joined along lengthwise
edges at 232.
It will be appreciated that the venting devices 180, 212 and 222 can all
be constructed using two flexible layers in the manner illustrated in Figures
6
18 to 8. Again, a preferred material for the inner layer 192 is ethyl vinyl
acetate
(EVA) formed with numerous, small perforations distributed over its inner and
outer surfaces and the same material can also be used for the outer layer
194, although there is no need for the outer layer to be perforated in the
case
of a venting device for a cast. The spacer members 196 can be similar in their
construction and layout to the spacer members 50' shown in Figure 6. That is,
24 they can be solid, elongate members that extend in the lengthwise direction
of
their respective half section. Of course, it is not necessary for the spacer
members to extend the entire length of the half section but there can be two,
three or more elongate spacer members aligned with one another, separated
by suitable gaps and together extending from one end 186 of the half section
to the opposite end 188.
30 As indicated, another suitable, flexible material for the inner and outer
layers is NyplexTM.
It will be understood that the venting devices 180, 212 and 222 can
either be custom formed so as to fit snuggly around a particular patient's
body
CA 02478162 2004-08-20
17
part, or they can be preformed in a number of standard sizes so that the
medical practitioner or doctor must select a particular, available size that
fits
his patient's body part sufficiently closely. It will, of course, be
understood that
if a chosen preformed venting device does not initially fit sufficiently close
around the body part, it generally is possible to trim one or more half
sections
6 so that that when the two half sections are combined, a sufficiently close
fit is
obtained.
One available procedure for manufacturing a venting device such as
that shown in Figures 10 to 12 is to shape a single layer, for example, the
inner layer of the venting device, on a suitable mold and, once shaped as
required, to heat the layer to a suitably high temperature that the layer
takes
12 on the shape of the mold and retains this shape once cooled. Spacer
members are then applied to the shaped layer in the desired manner, forming
the required air passageways between them. Then a second layer of flexible
material, normally the outer layer, is added, and is connected, for example,
by
adhesive, to the spacer members. This outer layer can then be suitably
heated so that it also will tend to retain the required shape. The two halves
of
18 the venting device can be made in this manner and, once completed, they are
placed around the body part so that they meet along their respective
lengthwise edges as shown in Figures 10, 16 and 17.
Turning now to the ventilated casts shown in Figures 13 and 14, these
are both walking casts provided with a supporting and ventilating device
constructed in accordance with a further aspect of the invention. The walking
24 cast 240 of Figure 13 is open at the front so that the patient's toes and a
portion of the venting device project from the front end of the cast. In the
walking cast 242 of Figure 14, the front end of the cast is substantially
enclosed. The supporting and venting device includes a rigid base plate 244
in the cast of Figure 13. This base plate has a bottom surface 246 which
forms a convex curve from its heel end to its toe end. This base plate is
30 shaped and sized to support firmly at least the major portion of a sole 248
of
the foot 250. The base plate has a network of open topped air passageways
252. These passageways can, for example, comprise several longitudinally
extending passageways that connect the illustrated transversely extending
CA 02478162 2004-08-20
18
passageways. Alternatively, the passageways can be laid out in the manner
of the passageways 66 shown in Figure 2, if desired. Several air
passageways (indicated in dash lines) can be provided at 254 to connect the
passageways 252 to the front surface of the base plate, thus allowing air to
circulate into and out of the passageways 252 when the base plate is
6 mounted in the walking cast.
Mounted on top of the base plate is a flexible sole layer 256 which can
either be flat or contoured (as shown) to fit the contour of the sole of the
foot..
This sole layer extends from a rear end 258 located at the heel of the user to
a front end 260 located at the toe of the user. If desired, the sole layer can
be
turned up at each end as shown. The sole layer is adapted to cover
12 substantially the top surface of the base plate and it is porous to permit
air to
flow between the air passageways 252 and a top surface 262 of the sole
layer. Preferably the sole layer 256 is elastomeric and is made of ethyl vinyl
acetate (EVA). One preferred material for the base plate is a suitable rigid
plastics material. It will also be seen that with this walking cast
arrangement,
the base plate is substantially covered and supported by the bottom of the
18 cast at 264.
The supporting and ventilating device of Figure 13 includes a flexible
venting. arrangement indicated generally at 266 connected to the base plate
244 and adapted to cover at least a top and sides of the foot 250 prior to
application of the cast material to form the walking cast. The preferred
venting
arrangement 266 is capable of circulating air to at least the top and sides of
24 the foot and includes two, substantially parallel layers of flexible
material at
268 and 270. At least the inner layer 270 is perforated and the preferred
material for this inner layer is EVA. The outer layer 268 can also be
perforated EVA material. By using perforated material for the outer layer (at
least in the toe region), air is able to circulate between the two layers and
to
exit from and enter into the passageways formed between the two layers in
30 the frontal region indicated at 272. In this frontal region, a front
section of the
outer layer 268 projects from the front end of the rigid cast. Located between
the two layers 268 and 270 are a number of elongate spacer members 274.
These spacer members can be made of EVA or NyplexTM and preferably
CA 02478162 2004-08-20
19
they extend in the lengthwise direction from top end 278 to the bottom end of
the venting arrangement. In this way, air is able to flow through the
passageways and reach the inner layer 270. This venting arrangement can be
attached by stitches located at 280 and 282 to the base plate.
Again, it will be understood that, a variety of different types of spacer
6 members can be used to separate and connect the inner and outer layers of
the venting arrangement 266. For example, the spacer members can be
similar to the spacer blocks 60 shown in Figure 8.
The walking cast shown in Figure 14 is similar in its construction to that
of Figure 13, except for the differences noted. In this case, the rigid cast
material substantially encloses the supporting and ventilating device,
12 including a rigid base plate 244'. In Figure 14 there is shown a lengthwise
extending passageway 252' and it will be understood that there can be a
plurality of these lengthwise passageways spaced apart from one another
and interconnected by transversely extending passageways such as those
illustrated in Figure 13. Short, interconnecting passages can be provided at
286 and 288 to connect the ends of the network of passageways 252' to the
18 passageways formed by the flexible venting arrangement 266'. Additional air
can be provided through optional frontal holes located at 290 which extend
through the cast material to a front end section of the venting arrangement.
Again, a flexible sole layer 256' covers substantially the top surface of the
base plate and this sole layer is porous to permit air to flow between the air
passageways 252' and the top surface of the sole layer. The spacer members
24 292 illustrated in Figure 14 are relatively short blocks similar to the
blocks 60
of the venting device illustrated in Figure 8. These blocks permit air to
enter
and exit through the top end of the venting arrangement indicated at 296.
Stitching can be provided at 298 and 300 to connect bottom end sections of
the venting arrangement to the base plate. As illustrated in Figure 15,
stitching can also be provided at 302 and 304 along the sides of the base
30 plate in order to connect the venting arrangement along the sides. For this
purpose, the left and right side edges of the base plate can be turned
upwardly as shown to facilitate stitching.
CA 02478162 2004-08-20
An optional feature of the walking brace of Figures 1 to 3 is the use of
strong plastic or metal connecting cables 306 and 308. These can be used at
both the top and bottom of the brace in order to securely connect the front
shell section 18 to the rear shell section 20. The cables extend through holes
6 provided in these shell sections on the left and right edges of the shell
sections. The purpose of these optional cable connectors is to ensure that the
front shell section is not removed except under medical supervision and
except when authorized. It may be desirable, for example, to prevent the
patient from inadvertently or otherwise removing the front shell section on
his
own and thereby injuring himself when the brace is removed. This type of
12 cable connector is well known in the connector art and a detailed
description
herein is therefore unnecessary.
It will be appreciated that it is also possible to construct footwear
incorporating features and principles of the walking braces described above.
In particular, footwear in the nature of work shoes and safety shoes can be
constructed, which includes an exterior shell adapted to fit around at least
the
18 foot of the person having interior and exterior surfaces. This exterior
shell can
be perforated with a large number of small, closely spaced perforations in a
manner similar to the orthopedic braces shown in Figures 3 and 5. These
perforations can extend over a substantial portion of the interior and
exterior
surfaces so as to allow air to pass through the shell between the surfaces.
Also, the footwear can be provided with an interior liner arranged in the
shell
24 which can be either rigid like the above described braces or somewhat more
flexible to make the shoe or boot more comfortable to wear. This interior
liner
would cushion at least the foot of the user and, if the footwear is a boot
that
extends up the lower portion of the leg, the interior liner can be extended to
also cushion the lower leg inside the shell. The liner is perforated over at
least
a substantial portion thereof so as to allow air to pass between the inner and
outer surfaces of the liner. Unless the footwear is equipped with an
inflatable
air cell, the liner can be a single layer of an elastomeric material such as
the
above described ethyl vinyl acetate (EVA). The perforated liner allows the air
to pass between the inner and outer surfaces of the liner. The footwear can
CA 02478162 2004-08-20
21
include at least one fastener for securing the footwear on the foot, for
example, a buckle, boot lace or Velcro TM type straps.
The aforementioned footwear constructed in accordance with the
invention can also include a shell that has a rigid base plate adapted and
arranged to support the sole of the foot. This base plate and its respective
6 liner can be similar to that illustrated and described above in connection
with
Figures 3, 5 and 9. The preferred base plate would also have a network of
open topped air passageways formed in a top surface thereof and apertures
for allowing air to flow into and out of these air passageways when the
footwear is being worn on the foot. The aforementioned footwear liner can
include a flexible sole layer covering the top surface of this base plate,
this
12 sole layer being porous to permit air to flow between the air passageways
and
a top surface of the sole layer.
It will be readily apparent to one skilled in the art of orthopedic braces,
casts, and footwear that various modifications and changes can be made to
the illustrated and described braces, casts, venting devices and footwear
without departing from the spirit and scope of this invention. Accordingly,
all
18 such modifications and changes as fall within the scope of the appended
claims are intended to be part of this invention.
24
