U.S. patent application number 09/829666 was filed with the patent office on 2001-09-06 for instrumented accelerometers for patient monitoring.
Invention is credited to Oyen, Duane P., Stark, John G..
Application Number | 20010020143 09/829666 |
Document ID | / |
Family ID | 25240514 |
Filed Date | 2001-09-06 |
United States Patent
Application |
20010020143 |
Kind Code |
A1 |
Stark, John G. ; et
al. |
September 6, 2001 |
Instrumented accelerometers for patient monitoring
Abstract
Exercise orthoses are described that include a frame, a fluid
bladder held by the frame, a pressure sensor attached to the fluid
bladder and a microprocessor receiving the pressure measurements.
The microprocessor monitors variations in pressure and determines
differences between the measured pressures and predetermined target
values. The frame can be designed to support a hinge joint or at
least one vertebra. Furthermore, corrective back orthoses are
described that include a frame, force applicators connected to the
frame to apply force to the patient's spine, a sensor that measures
forces associated with the force Applicators and a control unit
that monitors forces measured by the sensor. The corrective back
orthosis can include fluid bladders as force applicators. The
control unit can include a microprocessor.
Inventors: |
Stark, John G.; (Deephaven,
MN) ; Oyen, Duane P.; (Maple Grove, MN) |
Correspondence
Address: |
Peter S. Dardi, Ph.D.
WESTMAN CHAMPLIN & KELLY
International Centre, Suite 1600
900 South Second Avenue
Minneapolis
MN
55402-3319
US
|
Family ID: |
25240514 |
Appl. No.: |
09/829666 |
Filed: |
April 10, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09829666 |
Apr 10, 2001 |
|
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|
08824065 |
Mar 24, 1997 |
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Current U.S.
Class: |
602/13 ; 602/19;
602/26 |
Current CPC
Class: |
A61F 2005/0188 20130101;
A61F 5/02 20130101; A61F 5/012 20130101 |
Class at
Publication: |
602/13 ; 602/26;
602/19 |
International
Class: |
A61F 005/00 |
Claims
What is claimed is:
1. An orthopedic device comprising: (a) a frame that can restrain a
first flexibly connected body portion of an individual relative to
a second flexibly connected body portion; (b) a bladder held by
said frame, where said bladder contacts at least one of said
flexibly connected body portions when said frame is restraining
said flexibly connected body portions; (c) a pressure sensor
attached to said bladder such that pressure within said bladder is
measured; and (d) a microprocessor receiving said pressure
measurements, where said microprocessor monitors variations in
pressure.
2. The orthopedic restraining device of claim 1, wherein said frame
comprises a hinge.
3. The orthopedic restraining device of claim 1, wherein said
bladder is positionable relative to said frame to adjust the rest
pressure within said bladder.
4. The orthopedic restraining device of claim 1, wherein said first
flexibly connected body portion of said individual and said second
flexibly connected body portion are connected by a hinge joint or
ball and socket joint.
5. The orthopedic restraining device of claim 1, wherein said first
flexibly connected body portion of said individual and said second
flexibly connected body portion are connected by at least one
vertebra.
6. The orthopedic restraining device of claim 1, wherein said
bladder holds air.
7. The orthopedic restraining device of claim 1, further comprising
an accelerometer to measure acceleration associated with said
flexibly connected body portions.
8. A corrective back orthosis comprising: (a) a frame that fits
around at least a portion of a patient's torso to surround a
portion of said patient's spine; (b) a bladder supported by said
frame, where said bladder is positioned to provide corrective
forces to said spine of said patient; and (c) a pressure sensor
attached to said bladder such that pressure within said bladder is
measured.
9. The corrective back orthosis of claim 8, further comprising a
microprocessor that monitors pressures measured by said sensor.
10. The corrective back orthosis of claim 9, further comprising a
graphic display interfaced to said microprocessor, where said
graphic display depicts the forces along spinal orientations of
said patient.
11. The corrective back orthosis of claim 8, further comprising a
valve providing for the release of fluid from said bladder.
12. The corrective back orthosis of claim 8, wherein said
corrective back orthotic comprises a plurality of bladders.
13. A corrective back orthosis comprising: (a) a frame that fits
around at least a portion of a patient's torso to surround a
portion of said patient's spine; (b) a force applicator connected
to said frame to apply force to said patient's spine; (c) a sensor
that measures forces associated with said force applicators; and
(d) a control unit connected to said force sensor for displaying
values related to said measured forces.
14. The corrective back orthosis of claim 13, wherein said control
unit comprises a microprocessor that monitors forces measured by
said sensor.
15. The corrective back orthosis of claim 14, further comprising a
graphic display interfaced to said microprocessor, where said
graphic display depicts forces along spinal orientations of said
patient.
16. A method of correcting spinal misalignment of a patient
comprising the step of applying appropriate corrective forces to
said spine using a back orthosis comprising a bladder and a
pressure sensor positioned to measure pressure associated with said
bladder, where said bladder is positioned to provide a contribution
to said corrective forces and is adjusted to a desired
inflation.
17. The method of claim 16, wherein said appropriate corrective
forces are oriented along a plurality of vectors.
18. The method of claim 16, wherein said back orthosis further
comprises a microprocessor, which monitors pressures measured by
said sensor and determines variation in said measured pressure and
predetermined desired values.
19. The method of claim 18, wherein said microprocessor is
interfaced to a graphic display to provide a graphic analysis of
spinal position and of the vectors of corrective forces used to
correct said position.
20. A method of correcting spinal misalignment comprising the step
of applying appropriate corrective forces to said spine using a
back orthosis comprising: a) force applicators connected to a frame
that fits around at least a portion of a patient's torso to
surround a portion of said patient's spine, b) a sensor that
measures forces associated with said force applicators and c) a
control unit that displays values related to said measured forces.
Description
FIELD OF THE INVENTION
[0001] The invention relates to orthotic devices and associated
methods that assist with healing or correction of musculoskeletal
defects or injuries.
BACKGROUND OF THE INVENTION
[0002] The musculoskeletal system involves a network of ligaments,
cartilage, muscle, bone and the like, which are generally
controlled by the nervous system. The musculoskeletal system is
subject to a variety of stresses, trauma and congenital defects.
Surgery may be required to address certain problems, and physical
therapy may solve other problems. In addition, a physician can use
a variety of orthotic devices such as braces to stabilize an
injured or diseased body part. The orthotic device may form an
integral component of the treatment process.
[0003] The treatment process can involve a variety of stages that
will strongly depend on the specific problem involved and on access
to effective treatment methods. Exercise is a part of many
treatment programs. It is known that properly designed exercise can
increase the speed and improve the quality of the healing of many
musculoskeletal injuries. But it is also recognized that
inappropriate exercise can cause additional injury or slow
healing.
[0004] Relatively sophisticated braces with built in transducers
can be used to monitor an exercise program. The transducers measure
the forces being exerted during an exercise routine. These braces
serve a variety of purposes. An important purpose is to assist
patients in monitoring their exercise while minimizing the risk of
additional injury. Furthermore, these braces can assist the
responsible physician to monitor efficiently the progress of the
patient and to adjust the exercise program according to the
progress or lack of progress by the patient.
[0005] Back problems are examples of musculoskeletal injury and are
ubiquitous in our society. The spine has 24 motion segments. Forces
and injury are concentrated at areas of transition between the
spine's most rigid and most flexible segments. This results in a
tendency towards degenerative problems at the lower levels of the
flexible elements of the lumbar and cervical spine. The spine
involves an interrelationship of static soft tissue (e.g.,
ligaments and cartilage), muscle, flexible connective tissue (e.g.,
facet joints and disc spaces), bone, and nerve elements (including
spinal cord, autonomic and radicular structure). This complex
structure creates an enormously complex problem for the clinician
attempting to assist a patient through a period of
symptomatology.
[0006] Exercise is important for achieving and maintaining a
healthy spine. Studies suggest that back muscles maintain the erect
posture of the spine throughout the day. This requires a certain
level of back muscle strength and endurance. This endurance is also
necessary for lifting and load carrying. Therefore, specific and
properly controlled exercises for back muscle strength and
endurance may be useful in preventing or improving some lower back
trouble.
[0007] In addition to problems of degeneration and weakness,
misalignment of the spine can result in a variety of problems and
can result in progressive degeneration. For example, adolescent
idiopathic scoliosis affects approximately 1 to 3 percent of the
juvenile population. The deformity appears during early adolescence
as lateral curvature of the spine in either single curve or double
curve patterns.
[0008] The most frequent locations of scoliosis are in the thoracic
(chest area) and lumber (lower back region). A common pattern is
the double "thoracolumbar curve" in which the spine resembles an
"S" as the spine curves first one way in the chest area, then back
the other way in the lower back. As the spine curves, it also
rotates, producing either thoracic or lumbar prominences.
Adolescent idiopathic scoliosis is a progressive disease, which
often grows worse with the passage of time. The progression rate is
significantly higher in young girls than in boys. Bracing can be
successful in reducing or arresting progression.
[0009] Besides producing an undesirable appearance, spinal
curvature can result in nerve compression as a result of
impingement on nerve roots passing out from the spine to the limbs.
In addition, spinal curvature can also result in reduced thoracic
capacity including reduced cardiac and pulmonary function. These
difficulties result from the size and shape of the chest. In
extreme cases, premature death follows a lifetime of discomfort and
deformity.
[0010] In certain circumstances, direct intervention to correct the
curvature of the spine is indicated. Ultimately, about one youth in
one thousand out of the general population is treated with bracing.
Back braces, such as the Jewett brace, can be used to apply
corrective forces to the spine.
[0011] The commitment to place an adolescent in a restricting
device that encompasses the main trunk for long periods of time is
a serious one due to the physical discomfort factors and the direct
expense of fitting the brace and monitoring the disease through the
treatment period. In spite of these deterrents, bracing is the most
frequent treatment for adolescent idiopathic scoliosis because of
the seriousness of the disease.
[0012] Surgery to fuse vertebrae in better positions is an
alternative to bracing. Often in this surgery, rods are inserted
along the side of the spine and tied to the vertebrae to hold the
vertebrae in a better position. This surgery is a major and costly
procedure and typically leads to lessened flexibility. Therefore,
every effort is made to minimize the impact of the pathology and to
avoid surgery, if possible. Alternatives to surgery include bracing
for passive correction of the spinal deformity, and exercise for
improved strength and control. Managed care providers often require
bracing before surgery is attempted to correct or to stabilize
spinal curvature.
SUMMARY OF THE INVENTION
[0013] The present invention involves a portable orthopedic
restraining device for the passive correction of biological
deformity and/or the exercising of muscles and other tissues
associated with a joint or joints of a patient. In preferred
embodiments the orthopedic restraining device includes bladders
with pressure sensors. The bladders absorb some of the forces, and
fluctuations in the bladder pressure provide for measurements of
the forces applied by the patient. Bladders spread the forces over
the patient's skin and provide a direct measure of the forces on
the skin to provide a warning if the pressures reach a level that
would cause injury to the skin.
[0014] The invention includes corrective back orthoses. The
corrective back orthoses provide for monitoring of the forces
applied by the orthoses to permit more optimal use of the orthoses.
In certain embodiments, bladders are used advantageously in the
force applicators. The corrective back orthoses can include
microprocessors for more sophisticated monitoring of compliance,
variations in applied force and estimates of changes in the
patient's condition.
[0015] Specifically, in a first aspect, the invention involves an
orthopedic restraining device including:
[0016] (a) a frame, which can restrain a first flexibly connected
body portion of an individual relative to a second flexibly
connected body portion;
[0017] (b) at least one bladder held by the frame, where the
bladder contacts at least one of the flexibly connected body
portions when the frame is restraining the flexibly connected body
portions;
[0018] (c) a pressure sensor attached to the bladder such that
pressure within the bladder is measured; and
[0019] (d) a microprocessor receiving the pressure measurements,
where the microprocessor monitors variations in pressure and
determines differences between the measured pressures and
predetermined target values.
[0020] The frame can include a hinge or an articulating section.
The bladder preferably is positionable relative to the frame to
adjust the rest pressure within the bladder. The bladder preferably
holds air. The first flexibly connected body portion of the
individual and the second flexibly connected body portion can be
connected by many types of joints such as hinge, ball and socket,
intervertebral disc or synchondrosis. The orthopedic restraining
device can further include a display for displaying a quantity
related to the pressure.
[0021] In another aspect, the invention involves a corrective back
orthosis including:
[0022] (a) a frame that fits around at least a portion of a
patient's torso to surround a portion of the patient's spine;
[0023] (b) a bladder supported by the frame, where the bladder is
positioned to provide corrective forces to the spine of the
patient; and
[0024] (c) at least one pressure sensor attached to the bladder
such that pressure within the bladder is measured.
[0025] The corrective back orthosis can further include a
microprocessor, which monitors pressures measured by the sensor.
The corrective back orthosis also can further include a graphic
display interfaced to the microprocessor, where the graphic display
depicts the forces along spinal orientations of the patient in
order to permit adjustment of the forces through changes in
pressure in the bladder. In addition, the corrective back orthosis
can include a valve providing for the release of fluid from the
bladder. The corrective back orthosis can include a plurality of
bladders.
[0026] The corrective back orthosis preferably further includes a
manual pump attached to the bladder such that activation of the
manual pump adjusts pressure in the bladder by varying the amount
of fluid within the bladder. The valve can be controlled by a
microprocessor. The corrective forces applied by the corrective
back orthosis preferably are oriented along a plurality of vectors.
The corrective back orthosis can include a plurality of bladders
with independently adjustable pressures.
[0027] In another aspect, the invention involves a corrective back
orthosis including:
[0028] (a) a frame that fits around at least a portion of a
patient's torso to surround a portion of the patient's spine;
[0029] (b) force applicators connected to the frame to apply force
to the patient's spine;
[0030] (c) a sensor that measures forces associated with the force
applicators; and
[0031] (d) a control unit connected to the force sensor for
displaying values related to the measured forces.
[0032] The control unit can include a microprocessor that monitors
forces measured by the sensor. The corrective back orthosis can
further include a graphic display interfaced to the microprocessor,
where the graphic display depicts the forces along spinal
orientations of the patient in order to permit adjustment of the
forces. The corrective back orthosis also can further include
strain gauges operably connected to the frame.
[0033] In another aspect, the invention involves a method of
correcting spinal misalignment of a patient including the step of
applying appropriate corrective forces to the spine using a back
orthosis comprising at least one bladder and a pressure sensor
positioned to measure pressure associated with the bladder, where
the bladder is positioned to provide a contribution to the
corrective forces and is adjusted to a desired inflation. The
appropriate corrective forces preferably are oriented along a
plurality of vectors. The back orthosis used in practicing the
method can further include a microprocessor, which monitors
pressures measured by the sensor and determines variation in the
measured pressure and predetermined desired values. The
microprocessor preferably is interfaced to a graphic display to
provide a graphic analysis of the spinal deterioration and the
vectors of the corrective forces used to correct the deterioration.
The microprocessor can control a release valve to adjust pressure
within the bladder. The method can further include the step of
estimating using the microprocessor evolving force vectors based on
estimated evolving conditions of the patient.
[0034] In another aspect the invention involves a method of
correcting spinal misalignment including the step of applying
appropriate corrective forces to the spine using a back orthosis
comprising: a) force applicators connected to a frame that fits
around at least a portion of a patient's torso to surround a
portion of the patient's spine, b) a sensor that measures forces
associated with the force applicators and c) a control unit that
displays values related to the measured forces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a perspective view of an exercise orthosis of the
invention on the leg of a patient, where the orthosis involves a
bladder.
[0036] FIG. 2 is a top view of the bladder of FIG. 1 removed from
the orthosis.
[0037] FIG. 3 is a perspective view of an alternative embodiment of
a fluid bladder positioned by the knee of a patient without the
remaining portions of the orthosis being present.
[0038] FIG. 4 is a side view of another alternative embodiment of
the bladder positioned by the knee of a patient without the
remaining portions of the orthosis being present.
[0039] FIG. 5 is a perspective view of an exercise orthosis
depicted around the lower back of a patient with fluid bladders
under the surface outlined with dashed lines.
[0040] FIG. 6 is a perspective view of the exercise orthosis of
FIG. 5 shown separately from the patient.
[0041] FIG. 7 is a perspective view of a corrective back orthosis
of the invention.
[0042] FIG. 8 is a schematic view of the forces applied to the
spine at three points by the corrective back orthosis shown in FIG.
7.
[0043] FIG. 9 is a schematic view of lateral forces applied by a
corrective back orthosis.
[0044] FIG. 10 is a perspective view of a corrective back orthosis
of the invention that applies lateral forces to the spine of a
patient.
[0045] FIG. 11 is a perspective view of an alternative embodiment
of a corrective back orthosis.
[0046] FIG. 12 is a front view of the corrective back orthosis of
FIG. 11, where the orthosis is opened to display the structure
within.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] The present invention involves the incorporation of
innovative technology to a variety of orthopedic braces. In a first
type of orthosis, an improved orthopedic restraining device, such
as a brace, involves the incorporation of a bladder into a device
that supports two flexibly connected body portions. Such a bladder
preferably is filled with a fluid, e.g., a liquid or gas. This
device is designed for exercise of the portion of the patient's
body within the device. The pressure within the bladder is
monitored for a variety of purposes.
[0048] In addition, a back orthotic applies corrective forces to a
patient's spine to assist with correcting improper curvature. The
orthotic includes force applicators for applying the corrective
forces. The force applicators can be bladders, which can be filled
with a liquid or gas. In any case, sensors are included for
measuring the corrective forces. In preferred embodiments, a
microprocessor monitors the application of the corrective forces to
provide the responsible physician with valuable information.
[0049] Exercise Orthosis
[0050] Bracing is used to support and align in many areas of
orthopaedics. The fundamental principles of bracing include
mechanical alignment, removal of abnormal stresses by providing
support, as with a splint or cast, and restoration of normal
physiology. While bracing is fundamental, it has limitations even
when involving a hinge joint such as the knee or elbow. The
limitations involve the fit of the orthosis to the soft tissue,
contact interface, e.g. skin care, and translation of the device
through physiologic or more limited range of motion.
[0051] With respect to the present exercise orthosis, the bladder
provides for cushioning of the forces within the brace generated by
the patient's exercising. Also, the bladder may spread the forces
over a significant surface area of the skin. The spreading of the
forces may vary according to the amount of fluid within the
bladder. Nevertheless, the forces on the skin can be sufficient to
injure the patient due to damage of or interference with neural or
circulatory functions. Measuring the pressure is a direct way to
determine if excessive forces are being applied to the patient's
skin.
[0052] In addition, the pressure is a measure of the forces being
exerted by the patient. In this way, the exercise can be monitored
to determine if the patient is following a predetermined exercise
routine. Orthoses for supporting a portion of the body and for
exercise, especially isometric exercise, have used strain gauges
within the structure of the device to measure the forces applied
during exercise. See, U.S. Pat. No. 5,052,375, incorporated herein
by reference. While the pressure in the bladder may not provide
directly the forces applied by the exercising patient, the pressure
can be used to monitor the exercise routine in a meaningful way if
the bladder is positioned and inflated properly.
[0053] Generally, the exercise orthosis will contain one or more
bladders attached to a frame. The frame can take any form that
provides a relatively rigid support. For example, the frame can
include molded polymer portions that fit around a body portion, or
metal supports that connect around a body portion using straps.
[0054] The positioning of the bladder will depend on the design of
the orthosis and the part of the body to be supported by the
orthosis. The bladder should be placed around the joint to be
exercised, such that the bladder, when inflated, will contact
either the muscle or connective tissue surrounding the joint. In
this way, the bladder or bladders can absorb one or more of the
significant forces applied by the patient against the brace.
[0055] Absorption of these forces by the bladder will result in a
change in the pressure in the bladder. The pressure in the bladder
is monitored to measure this change. An empirical determination can
be made by correlating the variation in pressure measurements with
corresponding forces applied by the patient. Such empirical
determinations are evaluated for a particular brace design and
bladder inflation. Then, an appropriate exercise routine can be
designed based on desired pressure changes. The exercise routine
can be reevaluated as treatment progresses.
[0056] The preferred fluid for placement in the bladder is air,
since air can be pumped easily into the bladder and released. A
variety of other fluids can be used such as inert gases and
liquids. Furthermore, a deformable gelatinous material can be used
in the bladder as long as a reasonable pressure can be measured
with the material. Also, materials can be used that change phase
such as liquids that form a gel once inside the bladder.
[0057] Preferably, the amount of fluid in the bladder is variable
for adjustment of the bladder within the orthosis. The apparatus
used to change the fluid amounts generally will depend on the
fluid. Unless air is used, a supply of the fluid will be needed.
The valves can be manually adjustable, or they can be controlled
electronically through a controller. A valve can be used for
filling the bladder, and a separate valve can be used for emptying
the bladder, although a single valve can be used. Unless the fluid
source is at high pressure, a pump will be needed to pump the fluid
into the bladder. An electrical pump can be used, but a manual pump
is preferred for cost considerations and for ease of use.
[0058] The bladder can be used in a sealed form such that the
amount of material within the bladder remains constant. Having a
constant amount of material within the bladder may not be optimal
since the orthosis generally can be reconfigured for different
orientations of the joint. The brace then would have to be
adjustable to accommodate the bladder with a constant amount of
material in the different positions. Whether the amount of fluid
within the bladder is variable or not, it may be desirable to have
adjustments, such as straps or hook and loop fasteners, to permit
repositioning of the bladders and/or to alter the resting pressure
on the bladder.
[0059] Referring to FIG. 1, an exercise brace 100 is depicted
supporting the knee 102 of a patient 104 in a frame 105. In this
embodiment, the two flexibly connected body portions supported by
frame 105 are the thigh 106 and the lower leg 108. Frame 105 can
include adjustable hinges 110 to permit variation in the angle of
brace 100. The angle typically is fixed at a selected position for
performing the exercises, which can be isometric, isotonic or other
exercises. Hinge 110 can be an electromechanical hinge or a
mechanical hinge. A standard hinge can be replaced by an
articulating section of the frame that functions as a hinge.
Various alternative structures for the hinge and the frame
generally are described in U.S. Pat. No. 5,052,375 and WO 96/36278,
incorporated herein by reference.
[0060] The brace 100 further includes a controller 112 for
monitoring and analyzing performance of exercise routines by the
patient 104. Controller 112 generally includes a display, which can
involve a series of lights or preferably a digital display.
Controller 112 preferably includes a microprocessor.
[0061] The microprocessor can be interfaced to provide information
to a physician. The interface can be provided by a port for
connection to another computer or to a modem. Alternatively, the
interface can be accomplished by transmission of electromagnetic
radiation such as radio waves to a nearby or more distant base
station. In some embodiments, the controller can be reprogrammed
remotely to adjust the exercise routine according to the evolving
status of the patient's condition.
[0062] In a preferred embodiment of controller 112, a
microprocessor based system has several subsystems. Preferred
subsystems include: power supply such as a 9 volt battery,
transducer bias circuit, transducer signal conditioning circuit,
analog to digital converters, a microprocessor such as a Motorola
68HC11, real time clock, RAM and non-volatile storage such as SRAM
or EEPROM, graphic display such as a 64.times.128 pixel LCD display
with corresponding driver, keypad, audible or tactile feedback
device, data link to transducer, and RS232 standard output for
serial connection or modem access. The total device can be
integrated into a single package or physically partitioned between
portions mounted directly on frame 105 and portions mounted in a
small case, which optionally can be attached to frame 105.
[0063] A preferred controller 112 stores a software program that
manages the use of the device for patient rehabilitation. The
software preferably provides for alerting the patient when
exercises are to be done using audible or vibrator signals. The
controller 112 under software control preferably provides
instructions on the exercises as well as feedback and reinforcement
messages to the patient.
[0064] A preferred controller 112 counts and tracks exercises in
both content and quality, stores the results in non-volatile
memory, and puts itself to sleep when inactive to conserve power.
The software program can wake up between exercise sessions to
confirm periodically the continued use of the orthopedic
restraining device 100 and to monitor the forces during a
non-exercise mode. The controller 112 preferably accepts software
program changes by way of an RS232 serial cable direct computer
link or via a telephone modem.
[0065] Brace 100 preferably includes a bladder 114, which can be
configured in a variety of ways based on the criteria described
above. In FIG. 1 the bladder 114 is approximately toroidal in
shape. The toroidal bladder 114 is placed with its center
positioned roughly over the knee 102. The toroidal bladder 114 can
be attached to the brace 100 in a variety of ways including
reversible attachment with straps having hook and loop fasteners
and permanent attachment by fastening sewing cuffs around another
portion of the brace 100.
[0066] Bladder 114 can be made from a variety of materials. The
material should be puncture resistant and comfortable against the
patient's skin. Preferred materials for bladder 114 include, for
example, natural rubber, synthetic rubber, thermo plastic
elastomers and combinations thereof FIG. 2 displays toroidal
bladder 114 separately from the rest of brace 100. Toroidal bladder
114 has an outlet valve 116 and a removable manual inflator 118
attached to the bladder 114 by way of a one way valve 120. A
variety of designs can be used for the manual inflator 118. The
outlet valve 116 is actuated by squeezing the valve. The manual
inflator 118 can be replaced with a variety of motorized pumps,
where the pumps are optionally operated by controller 112.
Similarly, the outlet valve can be replaced by an electrically
controlled valve. Alternatively, a single valve can be used for
inflation and deflation. Any of a variety of commercially available
valves can be used.
[0067] The bladder 114 preferably includes a pressure sensor 122
connected using wire 124 to controller 112. The pressure sensor 122
can be any reasonable type. A variety of suitable pressure sensors
are commercially available. Preferred pressure sensors include the
MPX series of pressure sensors manufactured by Motorola because of
their linear output and small size. Other suitable pressure sensors
use silver oxide ink surfaces separated by a dielectric material.
If excessive pressures are measured, an alarm can be designed to
warn the user in order to avoid skin damage. Furthermore, the
pressure readings can be used to monitor the exercise routine, as
described further below.
[0068] Alternative embodiments of the bladders can be used. Also, a
plurality of bladders can be used. These bladders may or may not be
positioned in the immediate vicinity of the joint to be exercised
since forces will be exerted against contact points within the
orthosis away from the joint. Some bladders may only serve to
cushion the brace while others are designed for monitoring the
exercise routine. Some or all of the bladders will be equipped with
a pressure sensor, and some of all of the bladders may be monitored
by the controller.
[0069] An alternative embodiment 130 of the bladder is depicted in
FIG. 3 in position around a knee 132 without the rest of the brace
present. The horse-shoe bladder 130 is similar to the toroidal
bladder 114 except that a section of the toroid is removed. The
horse-shoe bladder 130 can be positioned with the open portion
oriented near the lower portion of the leg 134 or near the top
portion of the leg 136. Horse-shoe bladder 130 is equipped with an
outlet valve 138, a manual inflator 140 connected by way of a
one-way valve 142 and a pressure sensor 144.
[0070] Another alternative embodiment 150 of the bladder is
depicted in FIG. 4. This roughly ellipsoidal bladder 150 is
designed to be placed at the underside of the knee 152. It is also
equipped with an outlet valve 154, a manual inflator 156 attached
by way of a one-way valve 158 and a pressure sensor 160.
[0071] Referring to FIG. 5, an exercise orthosis 200 can be
designed to fit the torso 202 of patient 204 in order to assist
with back exercises. Back orthosis 200 can include one or more
bladders 206. Preferably, a plurality of bladders 206 are included
within back orthosis 200 to avoid putting pressure on the
spine.
[0072] Back orthosis 200 should be positioned to support a portion
of the back for exercise. A different orthosis may be needed to
exercise each different portion of the back depending on the design
of the orthoses. The brace can be used for isometric exercises or
other exercises, such as scoliosis exercises where the patient
moves counter to the forces being exerted on the back to decrease
the forces.
[0073] Referring to FIG. 6, at least one of bladders 206 includes a
pressure sensor 208 to measure the pressure within the bladder 206.
Pressure sensor 208 is attached to controller 210 by wire 212.
Controller 210 functions similarly to controller 112 described with
respect to FIG. 1. Bladders 206 can be filled and emptied in a
variety of ways depending on the fluid used. In one preferred
embodiment where air is the fluid, valve 214 is used to inflate or
deflate both bladders 206 depicted. Detachable ball 216 can be used
to inflate bladders 206 by manual pumping. Pressure generally is
affected by the physical conditions such as temperature and
positioning on the brace.
[0074] Referring to FIGS. 5 and 6, orthosis 200 preferably has a
relatively rigid frame 218. Preferred materials for the frame
include a variety of polymer materials, possibly combined with
natural or synthetic fabric and/or metal. Ventilation holes 220 can
be put in the frame 218. Padding can be included, if desired. A
large variety of approaches can be used to secure the orthosis to
the patient. FIG. 6 depicts a design using straps 222 having mated
plastic clips 224, 226 attached to the ends of the straps 222. The
exact number of straps and types of clips can be varied, as
desired.
[0075] When the portion of the back within the orthosis is
stressed, the pressure in bladders 206 will increase due to the
forces exerted against the orthosis. As with the other embodiments
of the exercise orthosis, the pressure fluctuations within the
bladder reflect the forces exerted by the patient. Therefore, these
pressure changes can be used to design a desirable exercise routine
and monitor the patient's compliance with the target exercise
routine.
[0076] Any of the exercise braces described above further can
include an accelerometer. For example, in FIG. 1 accelerometer 160
is depicted on the orthosis 100. Appropriate accelerometers
include, for example, single chip accelerometers described in the
1996 Allied Electronics Catalog. The accelerometer 160 can be used
to monitor motions at other joints associated with the joint
restrained by the brace. For example, an accelerometer 160
connected to the knee brace 100 can be used to measure motion at
the hip joint. The accelerometer 160 preferably is connected to
controller 112 for monitoring the accelerometer measurements.
Measurements from the accelerometer 160 can be used to measure
performance attributes of the patient, especially for athletically
active or impaired patients.
[0077] The accelerometer can be especially useful with respect to a
back orthosis. There are many ways of bending the back using a
variety of muscles. In addition, there are methods of moving the
back as a unit involving muscles outside of the back, e.g., hip
muscles. The forces exerted by some of these muscles can be
measured through the use of a strain gauge or a pressure gauge
combined with the bladder embodiments as described above. Forces
exerted by muscles connected to joints not within the brace cannot
be measured by force measurements within the brace. Rapid
accelerations of the body or spine may imply improper use or
injury-prone behavior. The patient may be overcompensating through
the use of other muscles for moving the back.
[0078] The use of an accelerometer can determine if the back is
being moved generally. The measurements of the accelerometer
provide an indication if these other muscles are being over-exerted
by the patient. If desired, an alarm can be set up to respond if
excessive acceleration is measured.
[0079] For use, the exercise orthosis is positioned around the
intended portion of the body connecting two flexibly connected body
portions. The orientation of the flexibly connected body portions
is adjusted as necessary, for example, by adjusting hinges within
the orthosis. The pressures within the bladders are adjusted to a
appropriate rest pressure by changing the quantity of material
within the bladder and/or by adjusting the relative position of the
frame and bladder using straps or other adjustments. Once
appropriately adjusted the patient exercises according to
instructions provided by a health professional. A particular
exercise routine may involve several orientations of the flexible
body portions.
[0080] Preferably, the patient exercises according to an exercise
routine designed by a physician based on the physical attributes of
the patient. The controller provides feedback to the patient with
respect to the actual performance relative to the target routine.
In preferred embodiments, the controller keeps track of the
patient's performance for evaluation by a health professional. The
health professional can adjust the target exercise routine based on
the recorded performance. The target performance can be made easier
if the initial routine was too difficult or more difficult to
account for progress in treatment. The exercise orthosis and the
corrective back orthosis described below also can be used for
behavior modification in terms of training an individual to use
proper posture and the like.
[0081] Corrective Back Orthosis
[0082] As described above, bracing generally involves several
challenges. The challenges for orthosis management are especially
acute for scoliosis bracing. Here, with life threatening
implications, the situation demands an optimum brace fit because
the application of forces to the treated joints is indirect. The
spine is simply not angled laterally, but it also may be rotated,
many times in areas away from easily accessible contact points.
Spinal curvature is complicated and aggravated by the dynamics of
gravity, contracture and growth.
[0083] After leaving a fitting session, a brace may rapidly become
loose, for example, due to weight loss or other fluctuation such as
water-weight variation. The forces within the brace may deteriorate
due to motor or viscoelastic responses as the brace is worn. In
addition, the brace may be too tight such that compliance by the
patient is difficult or impossible.
[0084] Furthermore, the efficient application of mechanical forces
to complex curves of the spine, within the limits of soft tissue
and bone anatomy, should be optimized by accurate quantitation of
forces and their changing relationships, amplitudes and
requirements over time. Single static adjustments of the brace are
made by a physician or technician based on point of time
information without information on the progression of events over
time.
[0085] With respect to the present corrective orthosis, one or more
of the force applicators that are used to apply desired corrective
forces to the spine have corresponding sensors to measure the force
being applied. The corrective forces are applied based on a
determination of the corrective forces needed to arrest or reverse
the misalignment. The applied forces generally can be applied to
control longitudinal and other deformities such as pure anterior or
posterior (kyphosis, lordosis), pure lateral bends (scoliosis) and
combinations thereof (complex scoliosis).
[0086] The force measured by the sensors can be displayed for ease
of adjustment. In alternative embodiments, one or more bladders are
used as force applicators in a corrective back orthosis to provide
cushioning of the forces. Monitoring the pressure in the fluid
bladder provides a quantitative measurement related to the
corrective forces.
[0087] The force measurements assist a person fitting the brace to
set the forces at desirable levels. Also, the force measurements
permit the patient to adjust the forces to appropriate values if
changes in fit of the orthosis occur between visits to the
attending health professional. If it is undesirable for patients to
adjust the forces themselves, at least the patients can monitor for
changes in the measured forces so that they can seek appropriate
adjustment by professionals.
[0088] Preferably, the force sensors are connected to a
microprocessor, which provides the capability to monitor the
variation in applied corrective force over time. The monitored
forces provided by the microprocessor assist invaluably with the
assessment of the progress with the brace. Minimally, the
microprocessor can be used to evaluate compliance by the patient,
which is a major issue with scoliosis bracing. The brace cannot
help if is not being worn. In addition, the force sensor can attach
to an alarm either through the microprocessor or separately to
provide a warning to the patient if the forces become
excessive.
[0089] Furthermore, the microprocessor can assist with fitting the
brace by providing a graphic display of the forces as they are
adjusted. In an active adjustment mode, the microprocessor can
alter the forces within the brace to ensure proper levels of force
to correct for unexpected changes in the forces or to alter the
forces as a function of time in response to expected changes in
spinal curvature. For example, if fluid bladders are used, the
amount of fluid within the bladder can be changed to adjust the
force. Alternatively, strap or other adjustments can be made to
alter the pressure without a pump.
[0090] Appropriate braces for these corrective orthoses support at
least a significant portion of the patient's torso. The material
used to make the brace should be relatively rigid, although some
parts of the side portions can be flexible without diminishing the
support significantly. Therefore, the patient's back is well
supported and the forces applied by the orthosis are relatively
constant. The brace can optionally include padding, which helps
distribute the weight of the brace and thereby provides greater
comfort.
[0091] Strain gauges can be attached to the frame to measure
stresses within the frame. Changes in the applied forces generally
occur along with changes in the fit of the frame on the patient.
Changes in the fit of the frame results in corresponding changes in
the stresses on the frame. Therefore, changes in stress can be used
as another indicator of changes in corrective forces being applied.
The strain gauges should be positioned at appropriate points along
the frame to provide an indication of changes in orientation of the
frame on the patient. These stress sensors may also provide a
measure of the amount of force applied by the force
applicators.
[0092] The stress sensors preferably are monitored by the
microprocessor along with the force sensors. If the applied forces
change sufficiently as measured by the force sensors and/or the
strain gauges to indicate excess, misdirected or inadequate
corrective forces, a warning can be provided that the forces need
adjustment. Note that the force sensors and the strain gauges can
both operate on similar or identical principle, but they are
applied to different types of measurements.
[0093] In a preferred orthosis, the force applicators are
repositionable so that they can be placed where desired and moved
as treatment progresses, if appropriate. The locations of the force
applicators can be programmed into the control unit. Based on the
force measurements, the microprocessor preferably determines the
force vectors and torques applied to the spine. These can be
graphically displayed on the control unit to allow for adjustments
to the forces. Then, these forces are monitored by the control unit
during use to evaluate forces applied over time to the spine and to
ensure compliance by the patient.
[0094] The microprocessor also can be programmed with the curvature
of the spine. Then, the microprocessor can use a three dimensional
polar view to account for twist in the spine as well as bends. The
forces can be related to the orientation of the spine to assist the
physician in setting the correct forces. The spinal curvature can
be updated and reentered into the microprocessor at subsequent
clinic visits.
[0095] Referring to FIG. 7, one embodiment of a corrective back
orthosis 300 is displayed. Shoulder straps 302, 304 are connected
to frame supports 306 and 308. Frame support 306 supports frame
members 310 and 312. Frame support 308 supports frame members 314
and 316. Strain gauges 318 are located on frame members 310 and
312. Similar strain gauges can be placed on frame members 314 and
316 and/or frame supports 306 and 308.
[0096] Bars 320 and 322 are attached to frame members 310 and 312
with pairs of adjustable brackets 324, 326 and 328, 330,
respectively. By loosening a pair of adjustable brackets, either
324 and 326 or 328 and 330, bars 320 and 322 can be moved up or
down along frame members 310 and 312. Similarly, bar 332 is
attached to frame members 314 and 316 at adjustable brackets 334
and 336. Loosening of adjustable brackets 334 and 336 permits the
repositioning of bar 332 to a desired position where the adjustable
brackets 334 and 336 are retightened.
[0097] Force applicators 350, 352 and 354 are located on bars 320,
322 and 332, respectively. Force applicators 350, 352 and 354
generally have a padded surface for contacting the patient. Force
applicators preferably include a force sensor, such as pressure
sensor 356, located on the padded surface or just below the padded
surface. Pressure sensor 356 measure the forces applied to the
patient as well as the pressure on the patient's skin. The pressure
sensors can be of the types described above with respect to
measuring pressure in a bladder. The pressure sensors preferably
are connected to a control unit 358.
[0098] In alternative embodiments, the force applicators include
fluid bladders with pressure sensors. The fluid bladders can be
sealed with a fixed amount of fluid, or they can be designed for
inflation and deflation.
[0099] The corrective back orthosis can include straps 360 and 362
attached to frame members 314 and 316. Straps 360 and 362 include
buckles 364 and 366. Buckles 364 and 366 can be attached to knobs
368 and 370 to secure the orthosis on the patient. Alternatively,
the straps can be attached to frame members 310 and 312. A variety
of other fastening devices can be used to secure the orthosis.
[0100] The orthosis 300 is positioned on a patient to produce one,
two, three or more points of force, as depicted in FIG. 8 with two
points of force applied from the back and one point of force
applied from the front. The bars are positioned to apply the forces
at the desired height. The orthosis can be altered to include more
than three force applicators such that forces are applied at more
than three points. Similarly, the relative numbers of forces
applied from the front and back can be changed.
[0101] The forces applied by corrective back orthosis 300 are
directed in a front-to-back and back-to-front direction
(collectively referred to as front-to-back forces below).
Alternatively, forces can be applied with forces in a lateral
direction as depicted in FIG. 9. Corrective back orthosis 400 in
FIG. 10 provides for lateral components to the forces.
[0102] FIG. 10 depicts an alternative embodiment 400 of the
corrective back orthosis. Corrective back orthosis 400 has a pelvic
girdle 402 and throat molds 404 connected by two upright supports
406 and 408. Upright support 406 is located along the front of the
patient during use, and upright support 408 is located along the
person's back. Corrective back orthosis 400 includes three side
straps 410, 412 and 414. A different number of side straps can be
used as desired.
[0103] Side straps 410, 412 and 414 are attached to the front
upright support 406 at brackets 416, 418 and 420. Side straps 410,
412 and 414 are attached to the back upright support 408 at
brackets 422, 424 and 426. Brackets 416-426 preferably are
adjustable such that the position along the upright supports 406
and 408 can be set as desired. Brackets 416-426 preferably include
strain gauges 428. Side straps 410, 412 and 414 can be detached in
a variety of ways so that the orthosis 400 can be put on and taken
off.
[0104] Side straps 410, 412 and 414 include force applicators 430,
432 and 434. Force applicators 430, 432 and 434 preferably include
pressure sensors 436, 438 and 440. Pressure sensors 436, 438 and
440 can be connected to a control unit 442. Strain gauges 428
preferably are attached to control unit 442. Control unit 442
preferably includes a microprocessor as in other control units
described above.
[0105] In alternative embodiments, the forces are supplied by one
or more bladders, either alone or in combination with other types
of force applicators. One or more of the bladders can include a
pressure sensor. The pressure sensor can be used to monitor the
forces against the skin as well as to monitor the corrective forces
applied by the bladder. Appropriate pressure transducers have been
described above with respect to exercise orthoses.
[0106] Corrective back orthoses 300 and 400 depicted in FIGS. 7 and
10, respectively, have a similar overall design. In preferred
embodiments, the features can be combined to include force
applicators positioned along the front and back as well as the
sides. Other basic designs can be used to construct corrective back
orthoses of the invention. One alternative design is depicted in
FIGS. 11 and 12.
[0107] Referring to FIGS. 11 and 12, corrective back orthosis 500
includes a front support 502 and a back support 504. Front support
502 is connected to back support 504 by a series of straps 506 that
can be disengaged to permit the patient to remove the orthosis 500.
Force applicators 508 can be placed in appropriate positions within
supports 502 and 504 such that desired levels of corrective forces
are applied when the orthosis 500 is in place. Alternatively, the
supports can be oriented along the patient's sides.
[0108] Removable bulbs 510 are used to pump air into bladders 508.
Valves 512 control air flow into and out of bladders 508.
Alternatively, electrical valves and pumps can be used to control
the fluid in the bladders 508. Also, force applicators 508 can be
pads or fluid bladders using fluids other than air. Fluid bladders
are preferred such that the amount of force can be adjusted with
the orthosis 500 in place by varying the amount of fluid within the
bladder.
[0109] Force applicators 508 can be made repositionable, for
example, by using hook and loop fasteners. A large fraction of the
inner surfaces of supports 502 and 504 can be covered with loop
fabric, and the backs of force applicators can include hook type
fasteners. If the force applicators 508 are repositionable, the
force applicators can be positioned as desired for a particular
patient at a particular point in time. The force applicators 508
can be positioned to apply front-to-back forces or a combination of
front-to-back forces and lateral forces. In alternative
orientations of the supports, the force applicators can be
positioned to apply lateral forces alone. The number of force
applicators 508 can be varied as desired.
[0110] Force applicators 508 preferably include force sensors 514.
Preferred force sensors are pressure sensors. Force sensors are
connected to control unit 516. Strain gauges 517 are attached to
supports 502 and 504. Strain gauges 517 preferably are connected to
control unit 516.
[0111] Additional cushions 518 can be included for comfort.
Additional cushions 518 can be pads or fluid bladders. If
additional cushions 518 are air bladders, a valve 520 and bulb 522
can be included to fill and empty additional cushions 518.
[0112] For use, an initial examination of the patient generally
takes place at a medical facility. Measurements are made of
deformity parameters as well as normative data on progression of
curve shape and resolution patterns needed to design treatment.
Information on the spinal curvature is reproduced from measurements
taken from x-rays. This information can be directly input into the
control unit for the brace. More preferably, this information is
first input into a base station, a microprocessor used by a health
professional to track patient's condition and progress. A
corrective vector prescription is determined based on the
measurements.
[0113] The information can then be downloaded from the base station
to the control unit by a variety of protocols. The base station
processor and control unit processor can be connected by RS 232
connection, by telephone modem or other similar connections.
Alternatively, the processors can transfer information through
radio frequencies using transmitters and receivers.
[0114] A representation of the deformed spine and the corrective
force vectors can be graphically displayed by the base station
and/or the control unit. The force applicators are positioned to
correspond to the locations of the force vectors. The pressures can
then be set to correspond to the magnitudes of the corrective force
vectors. The control unit preferably monitors the pressure
measurements to provide a warning of excess, misdirected and/or
inadequate corrective forces. The corrective forces are established
according to desired parameters.
[0115] The patient generally then wears the brace away from the
care of the health care provider. The control unit monitors
compliance and any variation in the forces within the brace. The
patient further can perform exercises within the brace. These
scoliosis exercises generally involve motions directed by the force
applicators to further the corrective activity. To perform these
exercises, the patient moves to decrease the exerted forces of the
force applicators. This requires muscular force directed similarly
to the forces exerted by the force applicators. These exercises can
be monitored by the control unit and later downloaded to a base
station for evaluation by a health professional.
[0116] Information monitored by the control unit can be
periodically downloaded to the base station. This information can
be transferred by a hard wire connection, transmission using a
modem over phone lines or by transmission using electromagnetic
radiation such as radio waves or infrared radiation. The downloaded
information can be evaluated by a health care professional. This
information can be used to reevaluate the selected corrective
parameters. Also, this information can be used to evaluate changes
in the applied forces.
[0117] In addition, periodic examinations can be made to remeasure
the deformity parameters. The deformity parameters preferably is
input into the base station and/or the control unit. The new
deformity parameters are used to select a new corrective force
vector prescription. This process is then repeated until sufficient
progress has been made that the treatment can be terminated, or if
insufficient progress is obtained such that alternatives to bracing
are attempted.
[0118] Other embodiments of exercise orthoses and corrective back
orthoses are within the claims.
* * * * *