U.S. patent application number 14/338304 was filed with the patent office on 2015-03-12 for auto-accommodating therapeutic brace.
The applicant listed for this patent is Donald M. Cohen. Invention is credited to Donald M. Cohen.
Application Number | 20150073322 14/338304 |
Document ID | / |
Family ID | 46200079 |
Filed Date | 2015-03-12 |
United States Patent
Application |
20150073322 |
Kind Code |
A1 |
Cohen; Donald M. |
March 12, 2015 |
Auto-Accommodating Therapeutic Brace
Abstract
The current invention is an accommodating apparel or brace. It
is intended to be convenient and comfortable. When the brace wearer
is at rest, the brace exerts only modest forces against the body.
When the brace wearer is active, the brace tightens and diverts
load to protect the body part. The brace accommodation may include
application of stronger fixation when activity begins and which
persists as long as the activity does. It may also include
application of forces around the body part to shift load away from
the target part. The accommodation also includes relaxation of
forces applied to the wearer when the wearer relaxes.
Inventors: |
Cohen; Donald M.; (Irvine,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cohen; Donald M. |
Irvine |
CA |
US |
|
|
Family ID: |
46200079 |
Appl. No.: |
14/338304 |
Filed: |
July 22, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12964608 |
Dec 9, 2010 |
8784350 |
|
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14338304 |
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Current U.S.
Class: |
602/13 ;
602/27 |
Current CPC
Class: |
A61F 5/0104 20130101;
A61F 2250/001 20130101; A61F 5/012 20130101; A61F 2250/0003
20130101; A61F 5/0102 20130101 |
Class at
Publication: |
602/13 ;
602/27 |
International
Class: |
A61F 5/01 20060101
A61F005/01 |
Claims
1-19. (canceled)
20. A brace apparatus for at least partial unloading of a joint of
a body part of a person, wherein the joint bears a compressive load
during use, and wherein the compressive load is substantially
smaller when the joint is at rest than when the joint is active,
the apparatus comprising: a first collar positioned anatomically
below the joint; a second collar positioned anatomically above the
joint; an electronic sensor; a fixation apparatus within at least
one of the collars, responsive to input from the sensor, and
configured to at least semi-automatically increase a fixation force
of the collar about the body part; a brace structure configured to
support a compressive load, and having (a) a first end coupled to
the first collar, and (b) a second end coupled to the second
collar; and an unloading mechanism coupled to the brace structure,
and configured at least semi-automatically to divert a portion of
the compressive load from the joint to the brace structure when the
joint bears the load.
21. The brace apparatus of claim 20, wherein the fixation apparatus
is selected from the group consisting of a fixation bladder, a
mechanical latch, an electromechanical latch, a motorized cable
apparatus, and a strap.
22. The brace apparatus of claim 20, wherein the joint is a knee
joint, and wherein the first collar is positioned on the calf, and
the second collar is positioned on the thigh.
23. The brace apparatus of claim 20, wherein the joint is a
vertebral joint, and wherein the first collar is positioned on the
hips, and the second collar is positioned on the rib cage.
24. The brace apparatus of claim 20, wherein the joint comprises at
least one of the following: an ankle joint, a knee joint, a hip
joint, a vertebral joint, an elbow joint, a neck joint, a wrist
joint, a shoulder joint, and a finger joint.
25. The brace apparatus of claim 20, wherein the sensor is
configured to detect a change in one of the following: a position
of the body part, an angle of the body part, acceleration of the
body part, force on the body part, and pressure on the body
part.
26. The brace apparatus of claim 25, wherein the sensor is further
configured to cause a proportional response to the change.
27. The brace apparatus of claim 26, wherein the unloading
mechanism is configured to apply counter tension to the joint upon
the proportional response to the change.
28. The brace apparatus of claim 20, wherein the unloading
mechanism is selected from the group consisting of a piston, a
cylinder, a rack and pinion, and a viscoelastic insole.
29. The brace apparatus of claim 20, further comprising a source of
energy comprising at least one of the following: a battery, a
capacitor, energy harvested from a compression of a collapsible
hydraulic container, a spring, a stored pressurized fluid, and a
flywheel.
30. The brace apparatus of claim 29, wherein the energy transfers
using a transfer mechanism selected from one of the following: a
hydraulic line, a flexible cable, and an electromagnetic
device.
31. The brace apparatus of claim 20, wherein the unloading
mechanism is further configured to reduce the diversion of the
compressive load when the sensor detects a change indicative of
relaxation of the joint.
32. The brace apparatus of claim 20, wherein the fixation apparatus
is further configured to automatically increase the fixation force
when the joint bears the compressive load, and automatically reduce
the fixation pressure when the compressive load is removed.
33. The brace apparatus of claim 20, further comprising a
controller, wherein the controller is configured to activate the
unloading mechanism to cause the first collar and the second collar
to be alternatively inflated and deflated,
34. The brace apparatus of claim 20, wherein the sensor is
configured to allow semi-automatic repositioning of the brace.
35. The brace apparatus of claim 20, wherein the unloading
mechanism is further configured to transfer the portion of the
compressive load from the joint to the brace structure after the
increase of the fixation pressure of the collar about the body
part.
36. A brace apparatus for at least partial unloading of an ankle
joint of a leg of a person, when the person stands on a surface,
wherein the ankle joint bears a compressive load during use, and
wherein in the compressive load is substantially smaller when the
joint is at rest than when the joint is active, the apparatus
comprising: a collar positioned anatomically above the joint; an
electronic sensor; a fixation apparatus within the collar,
responsive to input from the sensor, and configured to at least
semi-automatically increase a fixation force of the collar about
the leg; a brace structure configured to support a compressive
load, and having (a) a first end attached to the collar, and (b) a
second end that is positioned to contact the surface; and an
unloading mechanism attached to the brace structure configured at
least semi-automatically to divert a portion of the compressive
load from the joint to the brace structure when the joint bears the
load.
37. The brace apparatus of claim 36, wherein the fixation apparatus
is selected from the group consisting of a fixation bladder, a
mechanical latch, an electromechanical latch, a motorized cable
apparatus, and a strap.
38. The brace apparatus of claim 36, further comprising an
automatic closure mechanism having an open state and a closed
state, wherein the automatic closure mechanism is configured to
provide an opening large enough to readily insert a foot into the
brace apparatus in the open state, wherein the automatic closure
mechanism is configured to be closed around the leg in the closed
state, and wherein the automatic closure mechanism is triggered by
the electronic sensor.
Description
[0001] This application is a divisional of and claims priority to
U.S. application Ser. No. 12/964,608 filed on Dec. 9, 2010. This
and all other referenced extrinsic materials are incorporated
herein by reference in their entirety. Where a definition or use of
a term in a reference that is incorporated by reference is
inconsistent or contrary to the definition of that term provided
herein, the definition of that term provided herein is deemed to be
controlling.
FIELD OF THE INVENTION
[0002] The field of the invention is supportive apparel, such as
orthopedic or therapeutic braces. More specifically the field is
accommodating braces that change in response to activity, or
physiological and therapeutic needs of the wearers. Principal
applications are reduction of force borne by arthritic joints or
compromised body parts (as with foot ulcers) and semi-automatic
apparel (such as shoes).
BACKGROUND
[0003] Supportive apparel is needed and used by many people. For
example, many people employ orthopedic or therapeutic braces to
reduce loading to a particular portion of the body. Supportive
apparel also includes footwear.
[0004] Orthopedic/Therapeutic Braces
[0005] There are many people who have clinical need to reduce the
force borne by a particular surface--such as the surface of an
arthritic joint, or the plantar foot surface when there is a foot
ulcer.
[0006] Many people experience joint pain. In fact, it is estimated
that well over 20 million Americans suffer from the effects of
osteoarthritis--a condition in which there is breakdown or erosion
of the cartilage that lubricates the bearing surfaces of the bones
in a joint. This results in pain and stiffness.
[0007] Cartilage protects bone surfaces at joints and produces
fluid to lubricate the joint. When too much cartilage in a joint is
worn away, compression in the joint can push two unlubricated bone
surfaces together. When the joint is flexed and the unlubricated
surfaces are moved against each other, the pain can be severe.
[0008] The pain of osteoarthritis is exacerbated when the
unprotected bone surfaces are pushed against each other--as for
example pain from an arthritic knee during walking. Without load
bearing, the osteoarthritis patient may well have full range of
motion in the joint, but the pain of bearing weight pushes bone
against bone (without the protective effect of cartilage and
synovial fluid) and thus makes even walking unbearably painful. If
the bone surfaces could be kept apart even a minute distance, then
the pain would subside.
[0009] Treatments utilized by these patients include
anti-inflammatory medication, analgesic medication, extracorporeal
prosthetic (cane or brace), implanted prosthetic (joint
replacement) or injection of lubricious media.
[0010] Braces are of several varieties. One variety limits range of
motion, mostly to limit potentially harmful movement in patients
following injury or surgery. Another variety of brace is an
unloader brace--which is intended to provide relief mostly for
those with arthritis. When an unloader brace is functioning in
accordance with the design principles, eccentric forces are applied
to avoid the most damaged portion of the joint. Compressive force
on the cartilage deficient bone portion of the joint is reduced.
This brace often accomplishes its goal by shifting the load
medially or laterally away from the most damaged portion of the
joint. Alternatively it is simply applied tightly enough as to
cause an increase in the gap between bone surfaces--as by reverse
barreling or the Poisson effect. There are many unloading knee
brace products and patents, for example U.S. Pat. No.
5,277,698.
[0011] Other braces are also intended to be affixed to the person
and bear all or part of the load of the affected joint; and in
addition have a mechanism to lock the brace. For example U.S. Pat.
No. 5,490,831 discloses a knee brace in which the articulating
hinge can be locked at a fixed angle to assist in walking. The
brace incorporates a heel strike mechanism as a trigger for the
locking mechanism. Similarly, U.S. Pat. No. 6,635,024 discloses a
brace that can be manually locked to allow the brace to support the
weight of the patient while standing.
[0012] Foot Ulcers
[0013] Another big need for an accommodating brace is reduction of
load borne by foot ulcers during normal walking activity. Load on
foot ulcers inhibits healing and exacerbates the condition. If the
ulcers are not healed, amputation can be necessary to preserve the
life of the patient.
[0014] There are about 20 million diabetics in the US and about 200
million worldwide. 15% of diabetics develop foot ulcers during
their lifetimes. Every year about 5% of diabetics develop foot
ulcers. There are about 120,000 hospital amputations of lower
extremities each year in the US, 60% of these are diabetic
patients. It has been reported that it typically costs over $20,000
to treat a foot ulcer over the 2 years following the initial
diagnosis. Clearly there are good reasons, financial and
compassionate to reduce the severity of foot ulcers, and to promote
healing. This can be accomplished by the use of a brace that
reduces or eliminates the load on the foot during normal
activities.
[0015] A frequent complication to foot ulcers is neuropathy that
severely reduces patients' ability to sense foot pressure or pain.
Without this feedback, patients will be unaware of continued damage
due to unsafe loading of the affected area. Consequently, more
passive treatment approaches are necessary to treat these
patients.
[0016] Treatment of foot ulcers includes dressing and debridement,
braces, orthotics, footwear and even total contact casting (in
which the foot and lower leg are encased in a cast to inhibit
weight bearing on the foot ulcer). It is crucial to reduce load
bearing of foot ulcers, because load bearing retards or even
reverses the healing process.
[0017] Foot Apparel
[0018] Another closely related technology is closure and tightening
technologies for athletic footwear. In 1989 Reebok sold athletic
shoes that used a manually operated integral air pump to tighten
the fit of shoes. Competitors for the Reebok Pump included LA Gear
Regulators and Nike Air Pressure. There are many patents that
disclose inventions that use bladders and other systems to allow
the user to manually improve fit, beyond the conventional lacing or
Velcro strap systems, such as U.S. Pat. Nos. 4,662,087, 4,763,426,
5,113,599 and 4,995,173.
[0019] Another patented athletic shoe closure includes the Boa
system, and the U.S. Pat. Nos. 5,934,599, 6,202,953, 6,289,558.
These shoes use a manually operated reel to snug a cable that
tightens the fit of the shoe.
[0020] Patent application 20090272007 Automatic Lacing System of
Beers et. al. assigned to Nike, Inc. teaches a lacing system for
footwear that uses a motor to drive an assembly that tightens laces
or straps when activated. This is reputed to be the power laces
system that gained notoriety when depicted in the film Back to the
Future II.
[0021] Limitations of Present Technologies
[0022] The aforementioned treatment alternatives have limitations.
The medication treatment options can reduce pain, infection and
inflammation in many people--though often incompletely.
Additionally, these can have deleterious systemic side effects.
These unwanted effects can sometimes be severe--such as ulceration
and hemorrhage (particularly gastro-intestinal).
[0023] Use of a cane to relieve the pain of an arthritic knee
indeed has some history of success by diverting weight to the arm
instead of the knee. The knee thus does not have to bear as much
compression so the compressive and shear stresses experienced by
the surfaces of the femur and tibia are diminished. Understandably,
the lower stresses result in diminution of pain. Of course the use
of a cane mandates an unnatural gait and occupies one hand--so a
cane does have large limitations. Additionally, the off-loading by
a cane is highly variable and unrealiable, especially with patients
who have neuropathy.
[0024] Implanted total or partial joint replacement can greatly
relieve symptoms. Limitations of this solution include cost, pain
and risk of surgery. Also, any failure of the replacement joint
necessitates additional surgery and attending cost, pain and
risk.
[0025] Injection of lubricious media (such as viscous hyaluronic
acid) within a joint has experienced mixed results. There has been
relief of arthritis symptoms--though generally temporary.
[0026] Often arthritis sufferers have asymmetric joint wear. A
person who has excessive cartilage wear in the medial portion of
the joint may benefit from an unloader brace that shifts the load
laterally. This is generally accomplished by judicious application
of the attachment straps that redistribute the weight of the
patient through the less diseased portion of the joint. This
implies that the healthier portion of the joint bears a larger than
normal load. For an unloader brace to function properly, it must be
tight--tight enough to force the wearer to stride in an unnatural
gait that shifts the load. Thus limitations of the unloader brace
are that it can not always achieve sufficient relief of symptoms
and that if it is tight enough to do so, that it is often
uncomfortable. Additionally, if there is slippage of the brace with
respect to the joint the functionality can be compromised.
[0027] Braces of the sort disclosed in U.S. Pat. No. 5,490,831
would suffer from similar shortcomings. They must be tight to work
at all--slippage frustrates the effectiveness of the braces. In
addition they are large and cumbersome. Also, though relatively
rigid, they do not reduce the load on the knee as an unloading
brace does.
[0028] Prior art devices, even those that share load with the
joint, are designed to (at most) limit how much the joint is
compressed. They can bear part of the compressive load that would
otherwise be fully borne by the joint. They do not apply counter
force or impose motion in the opposite direction of the compression
to spare the joint.
[0029] In the treatment of foot ulcers, dressings and debridement
can promote healing, but this is futile if the patient continues to
apply pressure to the ulcer by walking on it. Braces, orthotics and
footwear can reduce the stress on the ulcers, but patients often do
not comply with the directive to avoid walking without them.
Patients do about 50% of their walking at home, but they only wear
the footwear that protects the ulcers about 15% of the time at
home. This is because the footwear can be uncomfortable and
inconvenient. For this reason, total contact casting is often used,
so that the patient cannot remove the footwear. Though this does
improve compliance, a cast is heavy and uncomfortable, and it
blocks access to the ulcer--compromising the care of the ulcer.
Additionally, some suggest that because casting requires more
intensive and fairly uncommon "fitting" skills, it is
underutilized.
[0030] There is thus a need for footwear that is more convenient
with better therapeutic potential than currently available options
that reduces load on foot ulcers.
[0031] It is an objective of the invention to accommodate to user
status. It is an objective of the invention to appropriately
increase fixation force as needed when the wearer uses the affected
joint or body part.
[0032] With respect to joint problems, it is an objective of the
present invention to provide accommodating apparatus that reduces
load on a joint or surface during use.
[0033] It is another objective of the invention to apply counter
force (or to increase the distance between bearing surfaces of
bones in an affected joint) when the brace wearer uses the affected
joint. It is a further objective of the current invention to apply
unloading force around the joint during load bearing and to
substantially remove the unloading force during non-load bearing
intervals.
[0034] It is a further objective to minimize the degree of slippage
of the brace compared to current braces or to automatically reverse
the slippage and so to maintain functionality during prolonged
used.
[0035] Another objective to continuously and automatically adjust
brace physiological changes experienced by the patient (e.g.
reduced edema) to maintain the targeted off-loading force
throughout its prescribed use.
[0036] With respect to athletic footwear, the current tightening
systems require manual user interface to achieve the optimal fit.
There is thus a need for athletic footwear fit systems that require
less activity from the wearer; i.e. the shoe should perform more of
the work in tightening and or sensing.
[0037] Another objective of the current invention is to also apply
force on the body to reduce edema, to improve venous drainage
and/or to improve arterial perfusion and lymphatic circulation.
Additional Prior Art Information
[0038] US Patents [0039] U.S. Pat. No. 6,635,024 Articulating knee
supports [0040] U.S. Pat. No. 5,490,831 Selectively lockable knee
brace [0041] U.S. Pat. No. 5,899,869 Orthopedic appliance with
weight activated brake and variable extension assist [0042] U.S.
Pat. No. 6,024,713 Leg support apparatus [0043] U.S. Pat. No.
5,277,698 Knee bracing method [0044] U.S. Pat. No. 7,311,687
Osteoarthritis brace [0045] U.S. Pat. No. 2,467,907 Corrective and
protective knee brace [0046] U.S. Pat. No. 5,125,400 Ankle brace
having multiple inflatable aircells [0047] U.S. Pat. No. 5,931,796
Lower extremity support apparatus [0048] U.S. Pat. No. 5,330,418
Multiaxis controlled motion knee brace with a four bar joint and
method for producing same [0049] U.S. Pat. No. 5,259,832 Multiaxis
controlled motion knee brace with a four bar joint and method for
producing same [0050] U.S. Pat. No. 4,850,877 Method of determining
stress effects in components of the human knee and anthropomorphic
leg device therefor [0051] U.S. Pat. No. 4,711,242 Control system
for knee joint [0052] U.S. Pat. No. 4,637,382 Motion-guiding
load-bearing external linkage for the knee [0053] U.S. Pat. No.
5,472,412 Limb brace with adjustable hydraulic resistance unit
[0054] U.S. Pat. No. 7,163,518 Walking leg support [0055] U.S. Pat.
No. RE37297 Dynamic orthopedic knee brace assembly [0056] U.S. Pat.
No. 5,934,599 Footwear lacing system [0057] U.S. Pat. No. 6,202,953
Footwear lacing system [0058] U.S. Pat. No. 6,289,558 Footwear
lacing system [0059] U.S. Pat. No. 4,662,087 Hydraulic fit system
for footwear [0060] U.S. Pat. No. 4,730,403 Pressurized ski boot
[0061] U.S. Pat. No. 5,113,599 Athletic shoe having inflatable
bladder [0062] U.S. Pat. No. 4,995,173 High tech footwear
[0063] US Patent Applications [0064] 20070232977 Flexible tether
member connecting a knee brace to a boot [0065] 20060135902 Knee
brace and method for securing the same [0066] 20070010772 ORTHOTIC
BRACE [0067] 20050240135 Osteoarthritis brace [0068] 20090272007
Automatic Lacing System
SUMMARY OF THE INVENTION
[0069] The current invention is automatic, accommodating apparel.
It is intended to be convenient, comfortable, and therapeutically
reliable. The apparel may take the form of a foot brace, a knee
brace, a back support or other accommodating apparel. As a brace,
it partially or completely diverts load off of a body part such as
an arthritic knee joint or an ulcerated foot. When the target body
part begins to bear load, the brace accommodates, and diverts a
portion of the load through the brace, away from the specified or
protected body part. When the specified body part ceases activity,
the brace accommodates again, and ideally assumes a more
comfortable fit for the patient.
[0070] The brace partially diverts load off of a body part (such as
an arthritic knee joint or an ulcerated foot) when needed. When the
target body part begins to bear load, the brace accommodates, and
diverts a portion of the load through the brace, away from the
target part. When the target body part ceases activity, the brace
accommodates again, and ideally becomes more comfortable for the
patient.
[0071] The apparel apparatus attaches to the body near or around a
foot, ankle, wrist, knee, elbow or other body part that requires a
reduction in ordinary load for therapeutic application or
protection. In general, contemplated apparatus include (1) a
fixation apparatus to affixes the apparel to the body proximate the
body part, (2) a detection apparatus to detect changes or activity
to or of the body, and (3) a mechanism that responds to the
detected change to divert load from the body part.
[0072] The accommodating action of the apparel may include
application of stronger or enhanced fixation when activity begins,
i.e. it holds more tightly to the body. It may also include
application of forces around the body part to divert load away from
the compromised body part. The accommodation preferably also
includes relaxation of the forces applied to the wearer when the
specified body part no longer needs protection.
[0073] As foot apparel for example, it senses the need for a change
in fixation; tightening when the user is walking, loosening or
unfastening when the user is seated or at rest.
BRIEF DESCRIPTION OF THE DRAWINGS
[0074] FIG. 1a is an isometric view of the front of the preferred
embodiment of most of the interior of an accommodating boot/brace
that transfers load that would otherwise be borne by the plantar
surface of a foot to the leg. The outer skin of the boot has been
omitted to permit view of the molded plastic weight bearing hinged
ankle chassis with rear entry doors, battery powered microprocessor
controller, door motor and mechanism, door latch and bladder
ballast.
[0075] FIG. 1b is an isometric view of the rear of the boot/brace
of FIG. 1a. This affords a better view of the compartmentalized leg
bladder, the pump and control valves, and the insole bladder.
[0076] FIG. 2a is an isometric view of a hinged ankle foot brace,
affording views of air pumps, inflatable leg straps, inflatable
sole, rigid bottom, ankle hinge and processor unit; in this view
the straps are fastened but not inflated; the sole is inflated.
[0077] FIG. 2b is an isometric view of the brace of FIG. 2a; in
this view the straps are fastened and inflated; the sole is
deflated.
[0078] FIG. 3a shows an isometric view of a rear entry hinged back
boot with the front right section depicted in cut-away view allow
better visualization of the inflatable boot liners and inner sole.
Also seen in this view are the cables that lift the hinged back
into place, the motor and gear head to pull the cables, a pump to
inflate the bladders, a valve manifold to direct the pressure, and
a package that includes sensors, battery and processor/controller
to detect foot insertion and walking and to control the pump,
valves and motor. In this figure, the hinged back of the boot is
shown in an open position that allows for easy foot insertion. The
bladders surrounding the leg can be seen to be in deflated
configuration. The in-sole is seen to be in the inflated
configuration.
[0079] FIG. 3b depicts the boot of FIG. 3a in a configuration where
the controller has operated the motor to pull the back of the boot
towards the closed position (normally following foot insertion);
has operated the motor to pull the back of the boot to the closed
position; has operated the pump and valve manifold to inflate the
bladders surrounding the leg, as would be consistent with the
detection of walking/load bearing; and has operated the valve
manifold to deflate the in-sole in order to partially transfer
walking load from the bottom of the foot to the leg via the
structure of the boot.
[0080] FIG. 4a is an isometric view of an accommodating foot brace
boot shown with a partial cut-away of the front right region. This
figure affords views of a rigid outer shell, an extendible,
inflatable posterior calf support, inflatable anterior leg support
and inflatable inner sole. In this view the boot is prepared for
easy foot insertion; the posterior leg support is retracted, the
anterior and posterior leg supports are deflated and the sole is
inflated.
[0081] FIG. 4b is the boot of FIG. 4a shown from the same isometric
perspective and partial cut-away. In this view the boot is depicted
in the configuration corresponding to foot presence in the boot;
the posterior leg support is extended, the anterior and posterior
leg supports are still deflated and the sole is still inflated.
[0082] FIG. 4c is the boot of FIGS. 4a and b shown from the same
isometric perspective and partial cut-away. In this view the boot
is depicted in the configuration corresponding to weight bearing;
the posterior leg support is still extended, the anterior and
posterior leg supports are now inflated providing fixation force to
the leg and the sole is still inflated.
[0083] FIG. 4d is the boot of FIGS. 4a, b and c shown from the same
isometric perspective and partial cut-away. In this view the boot
is depicted in the configuration corresponding to walking; the
posterior leg support is still extended, the anterior and posterior
leg supports are still inflated and the sole is now deflated, thus
reducing load on the sole.
[0084] FIG. 5a isometrically depicts the skeleton of a brace
awaiting foot insertion.
[0085] FIG. 5b depicts the structure of the boot in a closed
latched inflated position corresponding to weight bearing.
[0086] FIG. 6 is a top level flow chart for a preferred embodiment
of a diabetic foot ulcer boot.
[0087] FIG. 7 is an isometric view of a knee brace of the present
invention depicted in the position in which the heel would strike
the floor--initiating a mechanism in which a flexible cable applies
counter tension to the knee joint.
[0088] FIG. 8 is an isometric view of another knee brace of the
present invention depicted in the position in which the heel would
strike the floor--initiating a mechanism in which a flexible cable
applies counter tension to the knee joint.
[0089] FIG. 9 is an isometric view of a hydraulic knee brace of the
present invention in which a hydraulic fluid applies fixation
forces to the leg and counter tension to the knee joint whenever
load is applied to a hydraulic reservoir positioned under the
foot.
DETAILED DESCRIPTION OF THE INVENTION
[0090] The apparel is used to accommodate to the needs of a wearer.
It is intended to be comfortable while the wearer is at rest;
comfortable enough that the wearer is not prompted to remove the
apparel while at rest--as is so common with other load diverting
braces.
[0091] Apparel is meant to include at least orthopedic brace,
sleeve, footwear, glove and belt.
[0092] Foot Brace
[0093] The accommodating brace may be used to divert load from the
foot to the leg of a wearer, as would be appropriate for a patient
with a diabetic foot ulcer or for a patient with a foot or ankle
injury. A brace to reduce load on foot ulcers would share many
characteristics of a brace to reduce load on the ankle. The braces
depicted in FIGS. 1 through 5 demonstrate some embodiments of
accommodating braces of this sort. During load bearing, the brace
tightens to the lower leg, and preferably deflates an in-sole so
that some of the load is transferred through the structure of the
boot/brace (from the ground to the leg), bypassing the foot and
ankle Fixation can be accomplished by hydraulic or pneumatic
bladders, or by straps, or by other equivalent means.
[0094] The application of extra fixation pressure can be applied
through bladders, straps, cable system (such as the Boa) or other
equivalent.
[0095] Preferred Embodiment of a Foot Brace
[0096] A description of the preferred embodiment of a brace to be
used to aid in the healing of diabetic foot ulcers follows and is
depicted in FIGS. 1a and 1b.
[0097] The brace or boot is intended to be as easy to put on as a
bedroom slipper, yet effective at diverting a portion of the weight
of the wearer from the plantar surface of the foot to the lower
leg. The chassis of the boot is a subassembly mostly of molded
plastic such as PETG. It preferably includes a live ankle hinge
with travel stops in both directions and it is strong and rigid
enough to bear more than the full weight of the wearer. The chassis
may be injection molded, vacuum formed or other equivalent. It is
light weight and strong. The chassis consists of a rigid molded
shoe 100 that is attached to a rigid molded upper chassis 110 by a
hinge joint on each lateral side. The rigid molded left and right
rear doors 120 and 124 are attached to the upper chassis by spring
loaded hinges (126 on the right side).
[0098] Sensing and controlling functions are processed and
controlled by the processor/controller mounted on the circuit board
200 and powered by the rechargeable battery 210.
[0099] When the wearer dons the boot and the presence of the foot
and leg is sensed, the processor signals the gear motor 220 to
apply tension to the cable 128 to pull the leaf spring door tab
(129 on the right side) to close both doors. When the doors close,
they are held securely by the plunger from the latch solenoid 230
and the latch clasp 130.
[0100] When the wearer stands or walks, the activity is sensed, and
the processor sends signals that tighten the fixation to the leg
thus redirecting some load from the bottom of the boot/brace to the
leg, thus bypassing the foot. The processor sends a signal to the
bladder fill solenoid valve to allow air to transfer from the
constant pressure ballast 250 to the compartmentalized leg bladder
140. Once the leg is securely held by the inflated leg bladder,
deflation of the insole 150 permits further unloading of the
plantar surface.
[0101] The deflation of the insole is passive, i.e. weight borne by
the insole causes it to deflate slowly. The air is forced out
through a restrictive opening so that it would take on the order of
a minute to empty, whereas the leg fixation bladders fill on the
order of a second. The leg is thus quickly held by the boot, and
then the load is reduced from the insole. Load is further diverted
away from sites of ulcers, lesions and stress concentrations by the
shape of the insole, i.e. low spots or cut-outs.
[0102] The volume in the ballast is replenished later as the
processor sends signals to the pump 240.
[0103] When the wearer ceases standing and walking, the relaxation
is sensed, and the processor sends signals to the bladder vent
solenoid valve 250 to reduce the fixation force on the leg of the
wearer, thus allowing for more comfort, i.e. when the processor
confirms the detection of the relaxation state of the wearer, the
tightening of the fixation is reversed. With the body weight load
removed from the insole, the insole re-inflates passively. The
driving force is provided by a foam rubber insert within the insole
bladder. Air slowly returns to the insole bladder through the
restrictive opening.
[0104] A similar alternative for the air bladder insole is a
viscoelastic insole in which the height of the insole also reduces
slowly with time under load. The insole could alternatively be
actively inflated and deflated so that the control of the unloading
is more directly influenced by the processor.
[0105] When the patient opts to remove the boot, the processor
sends signals to the bladder vent solenoid valve and to the
solenoid latch to release the latch, and then to the motor to open
the doors. The wearer may manually release the latch and open the
doors.
[0106] The boot allows for rear entry so that a patient can don the
boot while seated or standing. The boot includes spring loaded
hinged rear doors that are closed by tensioned cables that are
pulled by a mid-line mounted gear motor.
[0107] Additional padding may be used for a custom fit and enhanced
comfort.
[0108] When worn, the chassis is covered with a leather, fabric or
equivalent fabric for fashion and protection and temperature
moderation.
[0109] The rigid sole has a rubber covering for traction and shock
absorption. The rubber may also include extra rocker, especially
for those with locked or no hinge chassis.
[0110] The chassis ankle hinge is free to pivot up to a forward and
rear lock orientation. The lock assists in transferring load
between the upper and lower chassis. In an alternative embodiment
the ankle hinge can be locked or even eliminated from the design
entirely.
[0111] Sensing of the foot and leg in the boot is accomplished by a
simple spring switch that is made when the shin closes it by
entering the boot fully. This helps to avert premature detection
and closing of the doors. There are many acceptable equivalent
alternatives, such as a load sensor under the forward portion of
the insole or optical sensor. Sensing of standing and ambulation
may be accomplished with the load sensor, with an accelerometer on
the processor board or equivalent.
[0112] The door latch may be a solenoid latch, a motor driven
latch, pneumatic closure or equivalent.
[0113] The medium to pressurize the ballast and the bladder is air,
but may be water, hydraulic fluid or other equivalent. A big
advantage of air is the lightweight assembly and the omnipresence
of air supply.
[0114] The leg bladder is divided into compartments for improved
fit, but fills as one. Compartments that fill separately are
acceptable, and in fact allow for a more customized fit and
sequential pressurization. The bladder walls are preferably heat
sealed high density polyethylene film, pvc film or other
equivalent.
[0115] The ballast allows for rapid filling of the bladder; at a
rate faster than the miniature pump can provide. The ballast is
designed to provide a large volume of air at a nearly constant
pressure in the range of 1 to 5 psi. The constant pressure ballast
may use a pressure regulated output, may be constructed of a
super-elastic body or membrane, may use constant force extensor
springs or may use other equivalent to deliver a nearly constant
pressure output. Preferably the ballast uses a latex membrane for
its high elongation and flat elastic modulus behavior. The ballast
may be eliminated entirely; and the pump may fill the bladder
directly.
[0116] The valves may be 2 way or 3 way, may be discrete or
manifold ganged or other equivalent. They may be solenoid,
piezoelectric or other equivalent.
[0117] Connections Among the Components are Made Using Flexible Pvc
or Silicone Tubing or Equivalent
[0118] A top level flow diagram for the process is shown in FIG. 6.
Beginning at the top, the processor operates the pump to assure
that the ballast is filled with pressurized air. It remains at the
ready until a sensor indicates that the leg is fully inserted into
the boot, whereupon it sends signals to the motor to close the
doors. The boot may remain in this state indefinitely. When weight
bearing activity is detected, the processor applies signals to the
bladder fill valve to allow pressure to the bladder to affix
tightly to the leg. This allows the wearer to walk with full brace
support. The insole plantar bladder passively deflates to allow
further unloading. The processor continually rechecks to confirm
that the wearer is still weight bearing, i.e. standing, walking,
ambulating. When a sensor indicates that weight bearing has ceased,
the leg bladder fixation pressure is eased for the comfort of the
patient. At this point the boot remains idle as the processor
continually checks to see if the patient resumes weight bearing or
elects to doff the boot. If weight bearing is resumed, the
processor repeats the actions that unload the foot. If on the other
hand, the patient has manually elected doffing, the processor
releases and opens the doors. It then sends signals to refill the
ballast and await the next insertion of the leg into the boot.
[0119] As used herein, the terms attach and affix refer to coupling
of the apparatus to the body in the manner of a removable brace,
i.e., by compression and friction.
[0120] Enhancements may be incorporated into the process. For
example, all of the processes may be closed loop, rather than the
open loop timed events of the preferred embodiment. Sensors can be
incorporated to indicate when the ballast is full, when the doors
are closed or fully open and when the bladder is at pressure.
Sensors can also detect boot fixation slippage, and can detect
level of activity. The processor can respond with higher fixation
and unloading levels to respond to higher demands. Running is a
higher demand than walking; walking is higher than standing.
[0121] Sensors can be incorporated which sense and cause response
to any of the following: position of the body part or a neighboring
body part or brace part, speed of the body part or a neighboring
body part or brace part, acceleration of the body part or a
neighboring body part or brace part, angle of the body part or a
neighboring body part or brace part, height of the body part or a
neighboring body part or brace part, presence or absence of a body
part in proximity to the apparel, force or stress on the body part
or a neighboring body part or brace part, temperature of the body
part or a neighboring body part or brace part, change of
temperature of the body part or a neighboring body part or brace
part, color or change of color of the body part or a neighboring
body part or brace part. These apply to a foot brace or boot, a
knee brace or other brace or apparel.
[0122] The processor thus accepts sensor data and establishes
parameter values indicative of the body part at rest or relaxation
state. It identifies a range that is indicative of the body part
not at rest, i.e. active or load bearing. The processor controls
the brace to accommodate to the activity; comfortable while at
rest; yet applied fixation and unloading or counter force applied
during activity or non-relaxation. The response is preferably
binary, but may alternatively be proportional, i.e. the magnitude
of the response is proportional to the value of a parameter that is
indicative of the level of activity or the amount of support
required.
[0123] Changes that affect the body part and sensed. When the
processor determines that the change is adequate to indicate that
the wearer is no longer in a relaxed state, the processor sends a
control signal to accommodate or change an aspect of the
brace/apparel. The aspect is preferably tightness of the brace, but
may be other aspects as well. The aspect of the brace changed may
be a dimensional change in the brace, a change in force at an
interface between the body and the brace, a change in pressure in a
portion of the brace (such as a bladder).
[0124] If slippage of the brace is sensed and confirmed by the
processor/controller, the processor/controller can send signals
that result in repositioning of the brace closer to a preferred
position. The repositioning of the brace can be accomplished in an
"inch-worm" fashion. In the case of a foot brace, this could
involve a momentary partial deflation of a leg fixation bladder
then an increase in inflation of an insole bladder during a leg
swing phase of gait. This allows the brace to move back towards the
preferred position and refasten the fixation in the improved
position. Similarly, this can be accomplished by proper sequential
operation of thigh fixation bladder, calf fixation bladder and
longitudinal extension actuator in a knee brace. This allows the
brace to "crawl" up a leg, preferably while unloaded.
[0125] The insole plantar bladder is passive, but could also be
actively inflated and deflated to permit even finer degree of
control, e.g. programmable degree of unloading of the foot.
[0126] The boot is available in a variety of sizes to allow close
fit to different foot dimensions of different wearers. To allow for
an even better fit, there can be custom fitting of the boot to the
individual. This entails insertion of pads/spacers between the
flesh and the boot. In the preferred embodiment, the custom fit
spacer is an extensible container that is filled by a fitting
practitioner (such as an orthotist) to allow the bladder to more
closely fit the wearer. This allows for a more comfortable fit and
also allows for faster accommodation during use since the change in
bladder volume (between relaxed state and active state) is
optimized. The extensible container spacer is filled with a
material that can be poured or injected into the container and then
hardens or sets quickly once fit to the wearer. The fill material
is injectable polyurethane foam or equivalent. The extensible
container may be fabricated from flexible sheets of
polyethylene.
[0127] Other alternative foot brace embodiments are depicted in
FIGS. 2-5. The embodiment of FIG. 2 illustrates how the invention
can be incorporated into a device that more closely resembles a
conventional ankle brace than a boot. It can be appreciated from
the figures that the compared to the bladders in FIG. 2a, the leg
bladders are inflated in FIG. 2b, thus gripping the leg tightly.
The plantar bladder of 2b is deflated, thus diverting some of the
load bearing to the leg. It can be further appreciated that
pressure at specific sites is further reduced by the shape of the
plantar bladder.
[0128] The boot depicted in FIG. 3 resembles a rear entry ski boot,
though it adds automaticity to allow for accommodation to the needs
of the wearer. It uses a motor driven cable drive to close the
door, and uses pneumatic bladders to affix to the leg and to reduce
pressure on the plantar surface.
[0129] The boot of FIG. 4 is similar to that in FIG. 3 though it
utilizes a pneumatic curtain to permit rear entry and leg fixation.
This boot requires very little rear side clearance, so it can be
donned even when it sits very close to furniture such as the edge
of a bed or chair.
[0130] The boot of FIG. 5 depicts a multi-element cable driven rear
entry closure mechanism.
[0131] Many other configurations are acceptable alternatives, such
as top, side or front loading--which may allow for easier donning
of the boot, particularly from a seated position.
[0132] Automatic Accommodation
[0133] Prior art devices have typically required manual
accommodation/control. For example, a brace wearer manually dons a
brace in anticipation of activity such as walking. The wearer
typically bends over and pulls the brace, shoe or boot on while
pushing the foot forward. Then the wearer manually fastens or
closes and tightens the brace, shoe or boot. In contrast, the
preferred embodiment closes around the foot automatically and then
latches closed. Further, the preferred embodiment detects when the
boot needs to be tightened, and then does so automatically.
Further, the preferred embodiment detects when the boot can be
safely loosened for comfort, and then does so automatically. The
boot closure, the fixation bladder inflation and deflation are all
automated.
[0134] A person using a typical prior art brace will consciously
decide to loosen the fixation of the brace when the person will be
idle for a while. In contrast, the preferred embodiment brace will
detect automatically the idleness of the person, and in this fully
automatic version it will automatically loosen the fixation for
comfort.
[0135] The boot/brace may be operated in a variety of
semi-automatic modes as well. The activation of boot closure and
fixation bladder inflation and deflation may each be controlled by
the wearer instead of by the processor/controller. Activation of
in-sole deflation may also be triggered by the wearer instead of
the processor/controller.
[0136] In a semi-automatic embodiment of the invention, a sensor on
the brace will detect the activity level and alert the wearer of
the condition. For example, a sensor can detect that the body part
is bearing more load than intended, and so the boot will deliver an
alert to the patient to suggest additional tightening of the
fixation and reduction in pressure in the in-sole.
[0137] In the preferred embodiment, detection of the state of the
wearer (at rest or active) triggers the brace to accommodate
accordingly.
[0138] Knee Brace Embodiment
[0139] For those with arthritis, the brace is meant to ease the
symptoms of joint pain during load bearing--in which the pain
subsides when the load is removed. A primary application is
osteoarthritis of the knee. In such a knee, the cartilage that
provides the lubrication that allows the knee to flex freely is
eroded. The brace applies counter tension to the knee joint at
least during load bearing. This tension pulls the femur and tibia
apart just enough to allow synovial fluid to infiltrate the area
thus reducing the pain of bone on bone flexion and reducing the
rate of erosion of the remaining cartilage. The counter tension is
removed so that the brace is not uncomfortable after the load
bearing ceases.
[0140] FIGS. 7 and 8 show examples of knee braces in which counter
force is applied to the knee with each foot step. A portion of the
weight of the body is used to pull the lower leg fixation away from
the upper thus reducing load and increasing clearance in the knee
joint.
[0141] In more preferred embodiments the brace is composed of a
lower leg collar, an upper leg collar, a pivot, an automatic
counter tension mechanism and automatic fixation tighteners as in
FIG. 9.
[0142] In a preferred embodiment of the current invention, the
upper and lower leg collars are similar to those common in the art.
The upper and lower leg collars are lightweight, rigid
subassemblies that are fastened to the skin of the lower and upper
leg respectively using conventional Velcro straps. The straps are
tightened enough to hold the brace in place so that its own weight
does not displace it. The straps need not be tightened
uncomfortably--as would be done with a conventional unloader brace.
There is a hinge or pivot connecting the collars and allowing for a
full range of motion to permit a normal stride.
[0143] The upper leg collar of the brace is attached to the skin on
the proximal side of the affected knee. The lower leg collar of the
brace is attached to the skin on the distal side of the knee.
[0144] While the wearer is at rest, the brace is intended to relax
so that it is less uncomfortable to the wearer.
[0145] General Version of the Knee Brace
[0146] Similar versions of the brace may be use on other joints. In
general, this version of the invention consists of a proximal
collar to attach to the skin of the wearer on the proximal side of
the joint, a distal apparatus (which may attach to the skin on the
distal side of the joint or may extend all the way to the ground in
an embodiment with lower extremity use), and apparatus to apply
force between these two to at least partially counteract a
compressive load that would otherwise be borne by the joint.
Preferably, the counter force is triggered by the presence of the
compressive load on the joint. After the compressive load
diminishes, the counter force diminishes as well. Preferably, the
counter force is triggered by the compressive load; and the
reduction of the counter force is triggered by the reduction in the
compressive load. Preferably the tightness of the fixation to the
skin is also triggered by the presence of the compressive load. The
brace fixation tightness when the joint starts to experience
loading; and the fixation loosens after the loading is
substantially reduced--indicative of relaxation of the joint.
[0147] Knee Brace Fixation
[0148] During much of the time that the person is wearing the
brace, the knee is not bearing the body weight, thus it is not
necessary to have the straps of the brace tight during those times.
This helps to avoid the discomfort of a load bearing brace. While a
person is seated for example there is no need to have the brace
fastened uncomfortably tightly. Also while the person is bearing
the weight on the fellow leg, there is similarly no need to have
the brace uncomfortably tight.
[0149] The tightness of the brace is increased as a precursor to
application of counter tension. As the foot strikes the floor, a
mechanism is activated that increases the tension of both the lower
and upper leg collars. The inflation of the bladders is
substantially completed before the maximum counter tension is
applied to the knee.
[0150] The fixation bladder is in fluid communication and fills as
a single entity. It is shaped to allow for multiple protuberances
to promote better fixation. The protuberances are barb shaped to
promote even better fixation in the direction needed, i.e. to
provide a very high frictional force that prevents the bottom
collar from sliding down and prevents the upper collar from sliding
up. The material is chosen for comfort, for high coefficient of
friction, for durability and for low compliance. A composite is a
good choice including a nylon screen for compliance and silicone
for durability, compatibility, low permeability and good
friction.
[0151] The fluid that fills the fixation bladders has low viscosity
so it fills the bladders quickly. It is a liquid so that it is
effectively incompressible so that the fixation force is
transferred effectively to the interface with the skin.
[0152] After load is removed from the foot, the fixation bladder
pressure is automatically reduced. While the brace is not
tight--there is ample opportunity for good circulation and cooling
for comfort.
[0153] Many alternatives are possible for the automatic fixation.
The fixation apparatus must be deployable and coupled to the load
bearing of the joint. The bladder can be multiple chambers or a
single. The protuberance can be single or multiple; there may be
rings, sawtooth, ridges; they may be circumferential, partial or
spot anchors. Many more possibilities exist. The fluid to fill the
bladders may be hydraulic or pneumatic. The fixation bladder may
consist of separate chambers that are alternately used so that
there is an extra relaxation period for the fixation anchor sites.
The shape of the pressurized bladder may be designed to facilitate
fixation. The bladder shape may be designed to facilitate closure
and attachment of the brace.
[0154] In fact the automatic fixation can be other than bladders.
It can be mechanical; for example--latches that are triggered by
load bearing on the leg. It could even be electromechanical--for
example a solenoid latch that is triggered by sensing of load
bearing on the leg.
[0155] In another alternative design, the fixation is automatically
held tightly to the leg whenever load bearing is detected and for a
period of at least 1 second after the load bearing ceases. In this
way, the brace remains tightly secured to the leg during
ambulation, but begins to loosen to a more comfortable level during
non-load bearing--such as sitting, or standing with weight borne by
the fellow leg.
[0156] Counter Force
[0157] In a preferred embodiment, counter tension is applied to the
joint when it is needed and is removed during other times for
comfort of the person and for effectiveness. The person with an
arthritic knee is not in constant pain while walking. The pain is
worst when the knee is forced to bend while bearing the body
weight. The weight squeezes out the synovial fluid and sets up the
conditions for excruciating pain. When a minute gap is imposed on
the joint, the lubrication returns and the pain subsides. This is
the case for example when the person uses a cane to divert some of
the weight around the knee. This is also the case with a tight
unloader brace, though the fixation of an unloader brace is static.
With every step, the force of the body weight exerts force to
counteract the unloading of the brace. With each step there can be
a little slipping. Every little bit of slippage makes the brace
less effective; and this can not be counteracted except by a manual
readjustment of the brace. In contrast, the brace of the present
invention applies counter force to the joint during load bearing
and then removes it. Any slippage that occurs during the course of
one step is reversed at the end of the step when the brace is
driven back by the counter tension mechanism to the start
position.
[0158] The automatic counter tension mechanism uses the body weight
itself to transfer some of the body weight load through the brace
external to the body rather than allowing the damaged knee to bear
the full weight. The objective is to remove enough load to allow a
minute gap between the femur and tibia for a rheological synovial
fluid load bearing layer--enough to avoid erosion and pain.
[0159] In one embodiment, the energy for the counter tension is
harvested from the compression of a collapsible hydraulic container
positioned under the foot of the arthritic knee leg. Fluid is
displaced from the container. The fluid travels up hydraulic lines
(low compliance flexible tubes: braid reinforced polymeric tubes)
to automatic fixation bladders and to the counter tension
mechanism. The fixation bladders fill quickly and the counter
tension mechanism is more gradual. As more and more body weight is
placed on the foot (and the underfoot hydraulic container), more
and more tension is applied to the knee.
[0160] As the maximum body weight is applied, the maximum counter
tension is applied to the knee. This maximum force is isometric;
i.e. maximum travel of the mechanism is achieved and further travel
is prevented by mechanical stops.
[0161] In an alternative version, the maximum is isotonic rather
than isometric. In this case the mechanism does not reach a
stop--the maximum counter tension is thus related to the maximum
body load.
[0162] The timing between activation of the automatic fixation and
the automatic counter tension is important. The brace must be well
fixed to the upper and lower leg before the cessation of counter
tension. The delay is designed into the hydraulics. A small
compliance is built into the line that feeds the counter tension
mechanism. This compliance chamber fills almost coincidentally with
the fixation bladder. When the compliance chamber fills to its
nearly rigid maximum, the fluid pressure in the cylinders drive the
pistons forward which apply counter tension to the knee. This fluid
resistance/compliance forms a calculable delay analogous to the
manner in which electrical resistance and capacitance form an RC
time constant.
[0163] In an alternative embodiment, the fixation and counter
tension mechanisms are connected in series. The hydraulic fluid
fills the fixation bladders first (tightly anchoring the brace),
and then begins to fill the counter tension activation cylinder
driving the pistons forward.
[0164] Many variations are possible. Rather than a piston cylinder
drive, there may be single or multiple hydraulic chambers,
cylindrical, oval or other shape. Rather than hydraulic, the drive
may be mechanical (as for example rack and pinion),
electro-mechanical or other equivalent.
[0165] The direction of the accommodating force can be in a
different direction than the axial counter tension load. It could
be in the lateral-medial direction or anterior-posterior direction
to transfer load away from the arthritic condyle to a healthier
portion of the joint.
[0166] Alternatively, the separation in the joint can be achieved
by application of nearly external pressure circumferentially around
the joint. This lengthens the region effectively by a reverse
barreling effect.
[0167] In the case of the foot/ankle brace, the counter tension is
applied by deflating the insole. Once the leg is affixed tightly to
the brace/boot, the deflation of the in-sole reduces the
compression on the ankle and the bottom of the foot. In an
alternative embodiment, force is applied to the leg in an upward
direction from the bottom of the brace/boot. This counter tension
reduces load on the ankle and foot. The deflation of the in-sole
achieves a similar result.
[0168] Sources of Counter Tension
[0169] In the embodiment of FIG. 9 the source of the counter
tension is the body weight collapsing a liquid filled bellows
underfoot. When that foot hits the floor, liquid is driven out of
the bellow as the height and the volume of the bellows are reduced.
The liquid travels up hydraulic lines to the automatic fixation
anchor and to the counter tension cylinder. The liquid drives the
piston up pushing the hinge up. This transfers through the brace,
the skin, fascia, muscle and other tissue to ultimately drive the
femur bearing surface slightly away from the tibia bearing
surface.
[0170] Clearly this same result can be accomplished through many
other embodiments. For example rather than a hydraulic drive, the
mechanism could use a rigid to transfer the body weight when
applied to the foot to mechanically pull the upper leg minutely
apart from the lower leg.
[0171] Alternatively, as shown in FIGS. 8 and 9, a flexible cable
can be used to transfer that force to pull the joint a bit
apart.
[0172] In other embodiments, the foot actuator could be entirely
eliminated. In one example, the energy to provide counter tension
is derived from musculoskeletal energy during angulations of the
leg.
[0173] In yet other embodiments the source of energy for the
counter tension is from a stored energy source. This could be for
example a battery or capacitor or other electrical energy storage
device which would be used to power one or more motors or solenoids
to apply motion to the brace; or the energy source could be the
weight of the body, the energy from the angulation/articulation of
the body, a battery, a capacitor, a spring, a flywheel or
equivalent energy source.
[0174] In still other embodiments mechanically stored energy would
be used for the automatic counter force. The energy could be stored
in a pressurized ballast in which there could be a pressurized two
phase fluid or a gas pressurized over a liquid. The mechanical
energy could be stored in a spring or even a flywheel.
[0175] For such systems using external energy sources, it would be
desirable to employ partial energy recovery--so that some of the
energy expended to drive the joint apart is recovered as it
passively returns back to the relaxed state.
[0176] Indicator
[0177] In other embodiments of the apparel, the accommodation is
simply alerting the wearer to the weight bearing of the affected
area--rather than applying counter force. The alert can be
auditory, visual, tactile or other equivalent. Examples include
buzzer, LED state and bell. There are many instances in which an
indicator is preferred--making the system open loop rather than
closed. The apparel apparatus would sense a heightened level of
activity of the wearer, and the processor would determine that the
apparel should be tightened for better efficacy. A buzzer could be
activated alerting the user who could then decide to depress and
hold the button that activates the inflation of the fixation
bladders, and then release the button when the desired tightness is
achieved.
[0178] Joint Load Bearing Sensing
[0179] In one embodiment, the joint load bearing sensing is
accomplished with an underfoot hydraulic bellows. The mechanism is
a liquid filled titanium welded bellows attached near the heel of
the foot wear of the person. The bellows has an exit that is
attached to low compliance hydraulic line that feeds into the
automatic fixation and counter tension mechanisms.
[0180] The bellow can alternatively be constructed differently with
other materials or constructions. It can have multiple exits. It
could be polymeric or metallic. Rather than a convoluted bellows it
could be more amorphous--as long as the walls exhibit low
compliance. In fact, the mechanism could be piston within a
cylinder (or other effective shape). It may be located under foot
or alongside as long as it is situated to bear at least a portion
of the body weight.
[0181] When coupled with an energy source other than the body
weight, the foot actuator could take other forms. The actuator
could be just a sensor to detect foot fall. A heel mounted load
cell would work. Alternatively an accelerometer, microphone or
equivalent could detect footfalls and even be mounted on the brace
rather than under foot.
[0182] In yet another embodiment, an underfoot mounted piezo device
could detect footfalls and even provide the power for the counter
tension.
[0183] In still other embodiments, the sensor detects the need for
counter tension by movement of the joint. For example, in upper
body joints, the joint may be relatively comfortable while
stationary. Any movement of the joint may elicit pain; thus any
movement would be detected and used to activate the counter tension
mechanism of the brace. For example, when the position or angle of
the humerus is changed relative to the radius--it is indicative
that the elbow joint is being used and that counter tension should
be applied. One way this could be accomplished is with a cam hinge.
For any movement of the joint, counter tension is applied--the
hinge rides on the high portion of the cam during such times. At
rest, the cam rotates so that the joint is on a low point of the
cam--counter tension is removed. The cam is pulled to this low
point (relaxed) position by a spring and dampener--so that counter
tension is applied to the joint any time there is motion--and
counter tension is removed when the joint is at rest.
[0184] In another embodiment standing and walking are detected with
data from an accelerometer as interpreted by the processor. Sensing
of standing requires accelerometer confirmation of verticality.
Sensing of walking requires detection of a predictable regular
swing of the detected angle of the accelerometer.
[0185] Sensing of the need for accommodation can be accomplished
with many different sensors. Sensing any appropriate variable or
parameter is acceptable. Deviation from a resting value of the
variable or parameter should indicate a need for brace
accommodation. It can have different values for example that
indicate sitting, standing, walking, running, jumping etc. It can
require processing, such as digital filtering. There should be a
range indicative of rest, and non-rest. Even more desirable is an
indicator that gives gradation of need for accommodation; this
would allow for proportional control. In a proportionally
controlled brace, the magnitude of the accommodation would vary
with the magnitude of the sensed parameter. For example, running
mandates more accommodation (such as counter force and fixation
pressure) than does walking
[0186] Knee Brace Hinge
[0187] The hinge is a simple pivot, though any coupling known in
the art is acceptable. There may be a complex hinge, a simple arc
or compound arc. There may be a cam and follower.
[0188] The hinge may by symmetric or asymmetric. There may be a
single hinge on one side of the leg or preferably both sides.
[0189] The foot/ankle brace in particular may function best with a
locked hinge. For comfort, it may be desirable to have the hinge
unlocked at times, for example in the absence of load bearing. In
one embodiment, the hinge is free to move except when loading of
the body part is detected, whereupon the hinge is restricted or
locked by the brace.
[0190] Knee Brace Controls
[0191] In the preferred embodiment the control of the brace is
accomplished automatically via hydraulic sensing/activation
mechanisms. An underfoot hydraulic bellows container senses the
load bearing--as liquid is pushed by the body weight out of the
bellows. Activation is accomplished as the liquid that exits the
bellows enters the deployable fixation chambers and then the
counter tension activation cylinders.
[0192] There are other acceptable alternatives. Other acceptable
sensors are other force, pressure or acceleration sensors. The
sensor could be located where it bears body weight, but it is also
acceptable to be located elsewhere as long as it still senses
footfalls.
[0193] The activation control in the preferred embodiment is an
automatic hydraulic mechanism, but it may be other control
mechanism, such as analog electrical, digital electrical or other
equivalent control. Use of microprocessor control for example would
enable complex timing relating weight bearing, fixation deployment
and counter tension activation.
[0194] Discrimination of standing, walking, jogging, running,
jumping and other physical activities can be interpreted from the
data. The brace can accommodate for each of these sensed activities
accordingly. For example, the fixation pressure will be higher for
jumping and running than it is for standing and walking
[0195] Applications
[0196] The brace is intended to promote patient compliance. It is
comfortable enough while the wearer is at rest that the wearer does
not remove it prematurely. The brace is meant to accommodate to the
demands of the wearer. While at rest, the brace is comfortable;
during walking, the brace deploys the fixation and/or counter force
elements.
[0197] Embodiments have been described for exemplary markets.
Accommodating braces that divert some load around a foot ulcer or
an arthritic knee joint have been described.
[0198] The brace may be applied to other joints. It may be used in
a similar manner for a sacroiliac, hip joint, vertebral joints,
etc. It could even be used for a finger, wrist, elbow, neck or
shoulder joint.
[0199] Other embodiments include athletic footwear: sneakers, ski
boots or snowboard boots that tighten when activity is sensed and
loosen when the athlete is at rest. In athletic footwear the
improved fixation is intended to enhance performance. In a
snowboard boot for example, increasing tightness during aggressive
riding is intended to provide more rapid weight transfer from the
body to the turning edges of the board. Enhanced activity is
planned for other sports wear as well.
[0200] Casual footwear applications are similar, e.g. shoes that
automatically fasten when the foot is inserted. These might be
particularly useful for toddler shoes or for adult loafers. This
adds convenience for the casual wearer and the athlete; it adds
functionality in children's footwear, as the children may not yet
have the capacity to properly affix footwear.
[0201] Yet other applications include apparel for other body parts;
for example a belt that senses motion and enhances back support.
During a swing, it allows a golfer to hit a ball more forcefully.
During daily activity, it provides support when lifting and helps
to reduce shock on the spine. Thus apparel of the present invention
may be designed for knee, ankle, plantar surface of the foot, hip,
vertebra, elbow, finger back, neck or other.
[0202] Additional Features
[0203] In addition to the features described, the brace can provide
other benefits; in particular reducing edema and improving
circulation. Because the brace includes bladders, valves, a pump
and a controller, the bladders can be filled in a manner that
accomplishes unloading of a body part when needed. That same
hardware can also be used in a sequentially activated manner that
facilitates the reduction of edema, or the improvement of venous
blood egression flow and arterial blood ingression. Low pressure
sequential pressurization of the bladders (in the retrograde
direction to push fluid back towards venous drainage into the
heart) then venting can be used to gently and gradually reduce
edema that is especially common in those with foot ulcers. Pressure
would generally be less than 20 mm Hg. Occasionally, higher
pressure sequential pressurization then venting can be used in the
antegrade direction can be used to assist arterial blood flow
towards the body part. This may be on the order of 100 mm Hg
pressure so that it can assist in the "peristaltic" pumping of
arteries.
[0204] Modifications
[0205] Thus, specific embodiments and applications have been
disclosed. It should be apparent, however, to those skilled in the
art that many more modifications besides those already described
are possible without departing from the inventive concepts herein.
The inventive subject matter, therefore, is not to be restricted
except in the spirit of the appended claims. Moreover, in
interpreting both the specification and the claims, all terms
should be interpreted in the broadest possible manner consistent
with the context. In particular, the terms "comprises" and
"comprising" should be interpreted as referring to elements,
components, or steps in a non-exclusive manner, indicating that the
referenced elements, components, or steps may be present, or
utilized, or combined with other elements, components, or steps
that are not expressly referenced. Where the specification claims
refers to at least one of something selected from the group
consisting of A, B, C . . . and N, the text should be interpreted
as requiring only one element from the group, not A plus N, or B
plus N, etc.
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