U.S. patent application number 10/100271 was filed with the patent office on 2003-03-27 for soleus pump.
Invention is credited to Isaksson, Will, Ravikumar, Sundaram.
Application Number | 20030060339 10/100271 |
Document ID | / |
Family ID | 26796979 |
Filed Date | 2003-03-27 |
United States Patent
Application |
20030060339 |
Kind Code |
A1 |
Ravikumar, Sundaram ; et
al. |
March 27, 2003 |
Soleus pump
Abstract
A "soleus pump" (foot pump) applies an oscillatory movement to
the sole of the foot so as to exercise the calf muscle and thereby
prevent development of deep venous thrombosis. In one embodiment,
the apparatus is placed under the lower leg of the patient, holding
the leg in an optimal position without the necessity of strapping
the apparatus to the patient or to the bed or table. The foot
motion is applied through a foot pedal incorporating a safety
feature which keeps the apparatus from jamming the patient's foot.
In another operating mode, the motor drive may be withdrawn, so
that the patient may drive the plate by voluntarily flexing the leg
muscles, as a form of exercise. In another embodiment, two
monopedal embodiments may be joined together to create a bipedal
version of the invention, permitting both legs to be exercised at
the same time. In yet another embodiment, the apparatus may be
adapted for use by a patient sitting upright, for example, in a
chair or airline seat.
Inventors: |
Ravikumar, Sundaram;
(Briarcliff Manor, NY) ; Isaksson, Will; (New
York, NY) |
Correspondence
Address: |
Ronald Abramson
Hughes Hubbard & Reed LLP
One Battery Park Plaza
New York
NY
10004-1482
US
|
Family ID: |
26796979 |
Appl. No.: |
10/100271 |
Filed: |
March 15, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60323410 |
Sep 18, 2001 |
|
|
|
Current U.S.
Class: |
482/80 ;
482/51 |
Current CPC
Class: |
A61H 2203/0431 20130101;
A61H 2203/0456 20130101; A61H 1/0266 20130101; A61H 2201/1261
20130101; A61H 2209/00 20130101; A63B 22/0056 20130101; A63B
2022/0038 20130101; A63B 22/0023 20130101 |
Class at
Publication: |
482/80 ;
482/51 |
International
Class: |
A63B 071/00; A63B
022/00; A63B 023/10 |
Claims
We claim:
1. An apparatus for exercising a leg, comprising: means for
supporting the leg so that the sole of the foot rests against a
movable member, and the weight of the lower leg is not resting on
the calf muscle or the back of the knee joint; said movable member
being secured in relation to said supporting means; means for
applying an oscillatory force to said movable member.
2. The apparatus of claim 1, further comprising; compressible means
for linking said oscillatory means to said movable member, said
compressible means limiting said force applied by said oscillatory
means to said movable member, and providing a mode whereby said
foot may apply a force to move said movable member in opposition to
said force applied by said compressible means.
3. The apparatus of claim 2, wherein said linkage of said
compressible means is unidirectional.
4. The apparatus of claim 3, wherein said compressible means
comprises a torsion spring.
5. The apparatus of claim 1, wherein said movable member is
pivotally attached to said supporting means.
6. The apparatus of claim 1, wherein said means for applying said
oscillatory force is deactivated.
7. The apparatus of claim 2, wherein said apparatus further
comprises: second means for supporting a second leg so that the
sole of the second foot rests against a second movable member, and
the weight of said second leg is not resting on the second calf
muscle or the back of the second knee joint; said second movable
member; second means for applying an oscillatory force to said
second movable member; second compressible means for linking said
second oscillatory means to said second movable member, said second
compressible means limiting said force applied by said second
oscillatory means to said second movable member, and providing a
mode whereby said second foot may apply a force to move said second
movable member in opposition to said force applied by said second
compressible means; means for connecting said first support means
to said second support means.
8. The apparatus of claim 7, wherein said means for connecting said
first support means to said second support means is adjustable.
9. The apparatus of claim 1, wherein said movable member is
slidably attached.
10. The apparatus of claim 9, wherein said means for supporting the
leg comprise: a thigh support; and an ankle support connected to
said thigh support.
11. The apparatus of claim 10, wherein said ankle support is
vertically adjustable.
12. The apparatus of claim 11, wherein said connection between said
ankle support and said thigh support is lengthwise adjustable.
Description
[0001] This application claims benefit of U.S. provisional patent
application serial no. 60/323,410, filed on Sep. 18, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is in the medical device field, and
more particularly relates to a pedal-actuated device to prevent
development of deep venous thrombosis (DVT).
[0004] 2. Description of Related Art
[0005] DVT has been of concern in situations where people are
immobile for relatively long periods, such as after surgery, or
during long airplane flights. Generally, muscle contraction in the
leg sends blood back to the heart, through the veins. If the
muscles are not used for an extended period of time, the lower
limbs tend to swell with stationary blood, and a clot may develop.
Such clots can be very dangerous, resulting in life-threatening
situations such as pulmonary embolisms, aneurisms, strokes, heart
attacks, etc., or less dramatic, but long lasting disabilities of
various sorts, as a result of clotted blood adhering to vein
walls.
[0006] Because of this potential danger, preventive measures
against DVT are standard in postoperative care. A number of
techniques have been developed. The current state of the art
technique of choice for doing this is to employ an apparatus in the
form of a cuff that slides over the leg, which provides an
undulating compression to the calf muscle to help drive blood back
to the heart. Among the drawbacks of the current cuff technology is
the relatively high cost of the pumping apparatus for the cuff, and
of the cuff itself, which must be disposed of after about three
days of use. Another drawback is that the cuff is not usable if the
leg is in a cast or has had incisions.
[0007] In other existing techniques, the patient's foot is flexed
in order to exercise the calf muscle. However, prior art versions
of foot pumps have numerous disadvantages, including that they
require the apparatus to be strapped to the patient's leg and to
the bed or table; they don't hold the leg in an optimal position
for allowing the lower leg muscle to act as a pump; and they apply
pressure to the back of the knee joint or calf, thereby restricting
blood flow in the lower leg. Thus, when these prior art versions
release tension on the muscle, the weight of the leg is still on
the muscle and vein. As a result, the vein in the leg is not
allowed to easily or completely fill with blood, therefore
producing a much less efficient pumping action.
BRIEF SUMMARY OF THE INVENTION
[0008] Accordingly, it is an object of the present invention to
provide a more cost effective and versatile apparatus for
preventing DVT than those currently available, consistent with
other important objects including safety, comfort and ease of use.
It is another object of the invention to provide both active and
passive modes of operation, so that the patient can either allow
the machine to provide the movement (passive), or supply the moving
force himself or herself (active) as a form of exercise. It is a
further object of the invention to provide an apparatus that holds
the patient's leg in an optimally comfortable position, which
position is also optimal for the function of the lower leg muscle
to act as a pump.
[0009] These and other objects of the invention are achieved with
an apparatus we refer to as a "soleus pump" (foot pump), which, in
one embodiment, applies an oscillatory movement to the ball of the
foot so as to exercise the calf muscle and thereby prevent
development of deep venous thrombosis. In this embodiment, the
apparatus is placed under the lower leg of the patient, who is
lying down, and the weight of the leg serves to locate the
apparatus without the need to strap the leg to the apparatus or to
fasten the apparatus to the bed or table that the patient is lying
on. The apparatus holds the leg in an optimally comfortable
position, which position allows the lower leg muscle to go
completely slack. This position allows the large vein in the leg to
easily fill with blood, which is optimal for the functioning of the
lower leg muscle to act as a pump. The foot motion is applied
through a foot plate or pedal that is driven through a spring
mechanism by an electric motor. The spring mechanism allows the
plate to be stopped by foot resistance without stopping the motor,
thereby preventing the apparatus from jamming the patient's foot.
In another operating mode, the apparatus may be adjusted so as to
withdraw the motor drive, so that the patient may drive the plate
by voluntarily flexing his or her own muscles, as a form of
exercise.
[0010] The details of this and other embodiments will be more
apparent from a review of the accompanying drawings and of the
description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIGS. 1a and 1b are side views of the elements of one
embodiment of the invention.
[0012] FIG. 2 is a detailed view of the drive mechanism of an
embodiment of the invention.
[0013] FIG. 3 is a detailed view of the foot pedal of an embodiment
of the invention.
[0014] FIGS. 4a and 4b are side views of an embodiment of the
invention, showing two different positions of the foot pedal,
representing, respectively, two operating modes.
[0015] FIG. 5 is a side view of a vertically adjustable ankle
support of an embodiment of the invention.
[0016] FIG. 6 is a perspective view of a bipedal embodiment of the
invention.
[0017] FIG. 7 is a detailed view of an adjustable connection
mechanism that may be used in a bipedal embodiment of the
invention.
[0018] FIG. 8a is a detailed view of an adjustable connection
mechanism between two thigh cushions in a bipedal embodiment of the
invention, which embodiment eliminates the need for an abduction
pillow, shown in FIG. 8b.
[0019] FIG. 9 is a perspective view of a lengthwise adjustable
embodiment of the invention.
[0020] FIG. 10 shows an embodiment of the invention which may be
adapted for use by a patient lying down (FIG. 10a) or sitting up
(FIG. 10b).
[0021] FIG. 11 is a detailed view of the support frame and drive
mechanism housing of the embodiment shown in FIG. 10a and FIG.
10b.
[0022] FIG. 12a and FIG. 12b are perspective views of an alternate
embodiment of the invention.
[0023] FIG. 13a is a perspective view of an alternate embodiment of
the invention with an adjustable foot pedal, while FIG. 13b shows a
detailed side view of the adjustable foot pedal mechanism.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] One particular embodiment of the invention is illustrated in
FIGS. 1-5, and is described in the text that follows. Other
embodiments of the invention, showing adjustable monopedal and
bipedal versions of the invention, are illustrated in FIGS. 6-9.
FIGS. 10-13 show additional embodiments and features of the
invention. Although the invention has been most specifically
illustrated with particular embodiments, its should be understood
that the invention concerns the principles by which the claimed
apparatus may be constructed, and is by no means limited to the
specific embodiments shown.
[0025] The first embodiment of the invention as referenced above
comprises a monopedal anti-embolic device that facilitates the
exercising of the lower leg, calf and foot muscles, while lying
down. The device may be used by people convalescing in beds. One
purpose of the invention is to attenuate the likelihood of the
development of vascular emboli (and the consequences thereof)
during long and extended periods of inactivity.
[0026] This embodiment safely and easily facilitates the exercising
of the lower leg by applying a preset amount of force to the bottom
of the foot causing the foot to pivot at the ankle and stretch the
calf muscle. This embodiment of the invention then reverses and
allows the foot to hang freely from the ankle and thus allow the
calf muscle to go slack. The invention may use the weight of the
leg to locate itself with respect to the bed and thus locate the
device in relation to the body, so that the device is not required
to be strapped to the body of the patient or strapped or bolted to
the bed frame (although in another embodiment, this device could be
strapped to the leg or externally affixed to the bed, if desired).
The invention also supports the leg in such a way as to prevent
heel sores and, by supporting the leg in a slightly bent-knee
manner, helps to align the foot to the pedal. This leg position is
also optimal for the functioning of the lower leg muscle to act as
a pump, because the weight of the leg is not resting on the calf
muscle, and there is no support point or pressure in the area
behind the knee joint. One embodiment of the invention has a
vertically adjustable ankle support to accommodate different ankle
shapes and diameters. In other embodiments, the lower leg may be
supported either at the ankle or higher up the leg, under the
calf.
[0027] Another embodiment of the invention has a sprung sliding
member on the foot pedal so as to accommodate an incorrectly
located ankle and help prevent the possible resultant friction
burn. In another operating mode, the invention can also be used
unpowered as an exercise machine by setting a switch to the
exercise pedal that will move it into its full compression
position. In this case, the patient then simply pushes against the
pedal causing the pedal and arm to move back and forth against the
preset spring.
[0028] The mechanism for one embodiment of the invention comprises
a reversible motor, a geartrain providing a very slow final output
to the arm and a torsion spring indirectly connecting the final
output shaft of the geartrain to the arm. The final output shaft of
the geartrain only engages the spring in its torqued direction so
that in the backward direction of the geartrain the arm is not
being pulled backward away from the foot but is only falling back
with gravity. This safety feature ensures that the pedal is only
driven in one direction and in that direction is only driven
through the spring with a safe preset amount of force.
[0029] Any of the foregoing features and embodiments may also be
incorporated in a bipedal embodiment of the invention, which would
allow a patient to exercise both legs simultaneously, if
desired.
[0030] FIG. 1a is a side view of one embodiment of the invention,
showing the various elements that comprise the invention, while
FIG. 1b shows the same side view of the apparatus with the
patient's leg in position. The apparatus comprises a thigh pad 101,
an ankle pad 103 and a foot pedal 109 that is attached through an
arm 107 to a drive mechanism 105. The drive mechanism 105
momentarily applies a measured or preset amount of pressure to the
bottom of the foot 123 of someone in the prone position so as to
flex and extend the foot at the ankle 121 in order to tighten and
release the calf muscles 117.
[0031] As shown in FIG. 1, this embodiment of the apparatus
comprises a thigh pad 101 and an ankle pad 103 to support the leg
119 in a slightly bent position so as to help locate the foot 123
and allow the foot 123 to hang freely. The slightly bent and
elevated position of the leg 119, aside from being an ideal resting
position for the leg, would also prevent bed sores on the back of
the heel 125. The thigh pad 101 and ankle pad 103 also sit on (or
may be affixed to or slidably affixed to) the frame 115 of the
device, thus using the weight of the leg 119 to anchor the device
to the bed, without the need for attaching the device to the bed or
table, or strapping the device to the patient.
[0032] The drive mechanism 105 comprises a simple motor-driven
device that puts a measured amount of pressure on the sole of the
foot 123 causing the foot to pivot at the ankle 121 and stretch the
calf muscle 117. The device then reverses and allows the foot 123
to hang freely from the ankle 121, thus allowing the calf muscle
117 to go slack. The device can only apply a preset amount of
pressure to the bottom of the foot 123 because the arm 107 is
spring loaded to the drive mechanism 105, so even if a particular
patient has a very limited range of motion the device will only
apply a given amount of pressure to the bottom of the foot 123 and
not try to force the foot 123 and ankle 121 beyond what it is
capable of moving.
[0033] FIG. 2 is a detailed view of the drive mechanism 105. In
this embodiment, the mechanism comprises a reversible shaded pole
alternating current (AC) motor (not shown), a geartrain (not shown)
which reduces rotation to about one revolution per minute (RPM)
final output to the arm 107, and a torsion spring 203 indirectly
connecting the final output shaft of the geartrain to the arm 107.
The motor is driven back and forth by limit switches on the final
output shaft of the geartrain. The final output shaft rotates
backward and forward about 70 degrees. The mechanism is supported
through frame members 208.
[0034] The final output shaft of the geartrain is indirectly
connected to the arm 107 through the torsion spring 203. The arm
107 with foot pad attached (not shown) is affixed to the output
flanged shaft 205 by a pin 213. One end of the torsion spring 203
is connected to the arm 107, and the other end is torqued against a
stop that is also connected to the arm 107. This means the spring
203 always has some preset torque on it (in one embodiment, this
preset torque is preferably approximately fifty in-lb) so that as
soon as the device engages, the foot 123 is engaging the foot pad
109 with, in this preferred case, approximately fifty in-lb of
torque. The arm 107 can be pushed backwards with slightly
increasing force as the spring 203 is wound tighter.
[0035] The output of the motor/geartrain is connected to the input
flanged shaft 202 and transmitted to the torsion spring 203 only in
the counterclockwise direction through pin 206 that pushes against
pin 207. Pin 207 pushes against torsion spring 203. The other end
of torsion spring 203 pushes against pin 209 which is affixed to
output flanged shaft 205.
[0036] The preload of torsion spring 203 is maintained by shaft
204. Pin 210 is affixed to shaft 204 and stops pin 209 which in
turn stops one end of the torsion spring 203. Disk 211 is affixed
to shaft 204 by pin 212 and stops the other end of the torsion
spring 203 with pin 207 which is affixed to disk 211.
[0037] This arrangement allows for driving the output shaft 205 in
only the counterclockwise direction and then only through the
preloaded torsion spring 203. Output flanged shaft 205 only rotates
counterclockwise when either the foot pushes against arm 107 or the
weight of arm 107 itself is over center enough to induce a
clockwise torque on output flanged shaft 205.
[0038] As a safety feature, the final output shaft of the geartrain
only engages the spring 203 in its torqued direction so that in the
backward direction of the geartrain the arm 107 is not being pulled
backward away from the foot 123 but only falling back with gravity.
The design of the mechanism completely isolates the geartrain and
motor from misuse. The geartrain and motor can only have the preset
torque of the spring 203 applied to it. This design is also safe
for the user because it only applies a preset amount of pressure to
the bottom of the foot 123 no matter how badly misaligned the
device is to the foot/leg/body of the user. In the release or
backward stroke the arm 107 is not driven, allowing the arm 107 to
stop if it encounters any resistance. For example, if the foot 123
slips off the pedal 109, the motor will not drive the pedal 109
against the top of the foot 123.
[0039] FIG. 3 shows a detailed view of the foot pedal and pad of
the invention. In this embodiment, the foot pedal 109 is attached
to the arm 301 through two fasteners 309. The foot pad 303 is on
the side of the foot pedal 109 that engages the bottom of the foot
123. The foot pad 303 is attached to the foot pedal 109 through two
vertical slots 307 with a spring 309. These slots allow the foot
pad 303 to slide up and down on the foot pedal 109 so as to
accommodate an incorrectly located ankle and to help prevent
possible resultant friction on the bottom of the foot.
[0040] FIG. 4 illustrates two different operating modes of the
invention. In one embodiment of the invention, the apparatus
comprises a switch for the motor with three positions: Off, On and
Exercise. With the switch in position 1 (Off), as shown in FIG. 4b,
the motor causes the arm 107 to be angled down away from the foot,
exerting no pressure on the foot, allowing the foot to hang freely.
With the switch in position 2 (On) (not shown), the motor causes
the arm to move back and forth slowly from close to vertical
(maximum pressure on foot), to close to horizontal (foot hanging
freely). With the switch in position 3 (Exercise), as shown in FIG.
4a, the motor causes the arm 107 to be close to vertical (maximum
pressure). In this position, the user simply pushes against the
foot pad 109, causing the spring-loaded arm 107 to rotate backwards
and forwards with a preset amount of resistance. In the presently
preferred embodiment, this preset amount of resistance is
approximately 50 in-lb of torque.
[0041] FIG. 5 shows an alternate embodiment of the ankle pad,
allowing vertical adjustment of the pad to allow better alignment
of the ankle with the pivot axis of the arm. In this embodiment,
the pad 501 is attached through a threaded support member 502 to
the support frame 504 using a threaded rod 503. As the threaded rod
503 is turned, the support member is kept from turning by a rod 505
that fits through a hole in the support member 502 and is attached
to the support frame 504. Turning the threaded rod 503 causes the
support member 502 to slide up or down on the rod 505, allowing the
pad 501 to be adjusted to the optimum vertical height.
[0042] In FIG. 6, two adjustable monopedal embodiments of the
invention may be joined together to create a bipedal version of the
invention, which permits both legs to be exercised at the same
time, if desired, with a separate motor for each leg. In this
embodiment, each monopedal half of the invention comprises a thigh
pad 601 with an adjustable connecting rod 621. A frame 615 supports
drive portion of the device, including drive mechanism 605 and
ankle pad 603 (which may be vertically adjustable, and which may
also be slidably affixed to the support frame 615). The drive
mechanism 605 is connected through an arm 607 to a foot pedal 609.
A foot pad (not shown) may be slidably attached to foot pedal 609
to allow the foot pad to slide up and down on the foot pedal 609 so
as to accommodate an incorrectly located ankle and to help prevent
possible resultant friction on the bottom of the foot. The thigh
pad 601 in this embodiment may be lengthwise adjustably connected
to the support frame 615, for example through telescoping tubes
623. Two thigh pads 601 can be connected to each other using
adjustable connecting rod 621, resulting in a bipedal
apparatus.
[0043] In additional bipedal embodiments (not shown), an adjustable
connection may be made between support frames 615, in place of or
in addition to an attachment between thigh pads 601, to provide
additional stability and/or to help maintain the correct distance
between the two halves of the bipedal apparatus.
[0044] FIG. 7 and FIG. 8a show detailed views of thigh pad 601 and
adjustable connecting rod 621 of the bipedal embodiment shown in
FIG. 6. In FIG. 7, adjustable connecting rod 621 is affixed to
thigh pad 601 such that connecting rod 621 may be placed in a
variety of positions, depending upon the particular configuration
of the apparatus desired. In a monopedal embodiment, connecting rod
621a is placed in a "stored" position, lying along thigh pad 601 so
that the longitudinal axis of connecting rod 621 is generally
parallel to the lengthwise direction of the apparatus. In alternate
monopedal embodiments (not shown), connecting rod 621 may be simply
detached from thigh pad 601, or may slide into a hole in thigh pad
601 for storage. To configure the apparatus for the bipedal
embodiment as illustrated, connecting rod 621 swings through
position 621b and is placed in "connection" position 621c,
projecting outward from thigh pad 601 in the direction of a second
thigh pad (not shown). The connecting rod of a second thigh pad is
similarly (but oppositely) positioned to project out from second
thigh pad toward first thigh pad 601. Connecting rods (e.g. 621c)
are then affixed to each other for a bipedal embodiment.
[0045] FIG. 8a shows details of one embodiment of adjustable
connecting rods for the bipedal embodiment described. In the
embodiment shown in FIG. 8a, two connecting rods 821a and 821b of
two thigh pads 801a and 801b, respectively, are slidably attached
to each other. In this embodiment, connecting rods 821a and 821b
have attachment holes 823 along the longitudinal axes of both
connecting rods 821a and 821b. When thigh pads 801a and 801b are
positioned a distance "d" apart, holes 823 of connecting rods 821a
and 821b are aligned so that attachment means (not shown) can pass
through aligned holes 823 of both connecting rods 821a and 821b,
thus affixing connecting rod 821a to connecting rod 821b.
Attachment means may be, for example, nut and bolt, pin, screw, or
any other means that serves to affix connecting rods 821a and 821b
to each other such that they are restrained from moving relative to
each other and such that distance "d" between thigh pads 801a and
801b is maintained.
[0046] Distance "d" is determined as appropriate according to the
requirements of each individual patient, and may depend upon
various factors, including the size of the patient or any injury
that the patient may have suffered. For example, in patients with
fractured hips or hip replacements, an abduction pillow as shown in
FIG. 8b is often kept between the patient's legs to prevent
dislocation of the hip joint. Using the bipedal embodiment as
described, thigh pads 801a and 801b may be adjusted to the correct
distance "d" to maintain the patient's hip position and eliminate
the need for an abduction pillow.
[0047] As shown in FIG. 9, an additional embodiment of the
invention comprises an adjustable connection between thigh pad 901
and drive mechanism support frame 915, allowing the overall length
of the apparatus to be adjusted to accommodate each particular
patient's leg size. In the embodiment shown, the adjustable
connection comprises telescoping tubes 923 which may be slidably
adjusted to a distance "1" so as to properly position the patient's
thigh in thigh pad 901 and the ankle in ankle pad 903. However, the
invention is by no means limited to this particular embodiment, and
the adjustable connection may be any means which allows the
distance "1" to be maintained between thigh pad 901 and support
frame 915.
[0048] The invention may also be adapted for use by patients in an
upright, sitting position (for example, during a long airplane
flight). In the embodiment shown in FIG. 10a, the patient is shown
lying down with the leg located in the apparatus in the optimal
knee-bent position, supported by thigh pad 1001 and ankle support
1003. Foot 123 rests against foot pedal 1009. In FIG. 10b, thigh
pad 1001 and ankle support 1003 are detached from the apparatus,
and the position of foot pedal 1009 is adjusted to accommodate foot
123 for a patient in the upright position.
[0049] As shown in the detailed view of FIG. 11a, foot pedal 1009
has two positions in this embodiment: one for sitting and one for
lying down. For the sitting position, ankle support 1003 (see FIG.
10a), which in this embodiment is attached through a slot 1027 in
housing 1029, may be detached from the apparatus. A flip-stand 1031
helps to position foot pedal 1009 for comfortable use in the
sitting position. As shown in FIG. 11b, flip-stand 1031 rests
against underside 1039 of housing 1029, but may be flipped out in
the direction shown by arrow A to form a support which raises the
front of the housing from the ground (see FIG. 10b and FIG. 11a).
In this embodiment, ankle support 1003 is vertically adjustable
using height adjustment control 1033, and the speed of the drive
motor may be controlled by use of a speed control dial 1035. Two
monopedal versions of this embodiment may be joined together
through an attachment bar (not shown) connected through tandem-bar
socket 1037 to create a bipedal version.
[0050] Another embodiment of the invention is shown in a front view
(FIG. 12a) and back view (FIG. 12b). Foot pedal 1209 and vertically
adjustable ankle support 1203 are attached to housing 1229.
Vertical height of ankle support is adjusted through height
adjustment control 1233, and motor may be controlled through speed
control switch 1235. Thigh support 1201 is attached through
connection rod 1223 to support frame 1215. Length may be adjusted,
or thigh pad 1201 and connection rod 1223 may be detached from
support frame 1215, using adjustment knob 1241.
[0051] In another embodiment, shown in FIG. 13a, the position of
foot pedal 1309 may be adjusted through a height adjustment knob
1343. As shown in the detailed view of FIG. 13b, turning height
adjustment knob 1343 causes foot pedal 1309 and mechanism 1349 to
be raised or lowered along threaded rod 1345. As the height
changes, mechanism 1349 rotates at pivot point 1347, and foot pedal
1309, which is attached to mechanism 1349, changes position.
[0052] Other embodiments or variations are possible without going
beyond the scope of the invention as described herein. For example,
the invention could be adapted to a different bipedal version that
would work similarly to the monopedal embodiment as shown in FIG.
1, having a single motor driving two pedals either in a parallel
fashion or in an opposing fashion (one pedal up, one down). Another
type of reversible motor could be used, or even a nonreversing
motor, driving the arm back and forth through a crank. The
embodiment as shown in FIG. 10b could be adapted to attach to the
back of a seat in an airplane, train, bus, car or other conveyance
for use by travelers. An embodiment in which the motor is replaced
by a pneumatic pump is possible, where the pneumatic pump supplies
energy to the drive mechanism as required. The spring provides an
optional exercise function and a safety factor. The exercise
function would be excluded and the safety factor accomplished by
either a torque-limiting device or a torque- or power-sensing
circuit. The pivoting arm with the pad on it could be replaced by
an arced piston or arced member with gear teeth on it that would
move in and out of a device, but still roughly match the motion of
the foot being rotated about the ankle.
[0053] It is apparent from the foregoing that the present invention
achieves the specified objects, as well as the other objectives
outlined herein. While currently preferred embodiments of the
invention have been described in detail, it will be apparent to
those skilled in the art that the principles of the invention are
readily adaptable to a wide range of other pedal-actuated
anti-embolic devices without departing from the scope and spirit of
the invention.
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