U.S. patent application number 11/107641 was filed with the patent office on 2005-10-27 for device and process for adjusting the height of and the relief force acting on a weight.
This patent application is currently assigned to Hocoma AG. Invention is credited to Bucher, Ranier, Colombo, Gery, Riener, Robert.
Application Number | 20050239613 11/107641 |
Document ID | / |
Family ID | 34932061 |
Filed Date | 2005-10-27 |
United States Patent
Application |
20050239613 |
Kind Code |
A1 |
Colombo, Gery ; et
al. |
October 27, 2005 |
Device and process for adjusting the height of and the relief force
acting on a weight
Abstract
A device for adjusting the height of and relief force acting on
a weight is especially provided to be used for walking therapy of
paraparetic or hemiparetic patients within a locomotion training
means. Said weight of the patient is supported by a cable. A first
cable length adjustment means provides an adjustment of the length
of the cable to define the height of said suspended weight. A
second cable length adjustment means provides an adjustment of the
length of the cable to define the relief force acting on the
suspended weight. This allows a quick and reliable determination
and adjustment of the height for different patients and of the
relief force within the training program of every patient.
Inventors: |
Colombo, Gery; (Forch,
CH) ; Bucher, Ranier; (Stallikon, CH) ;
Riener, Robert; (Munchen, DE) |
Correspondence
Address: |
LERNER, DAVID, LITTENBERG,
KRUMHOLZ & MENTLIK
600 SOUTH AVENUE WEST
WESTFIELD
NJ
07090
US
|
Assignee: |
Hocoma AG
Volketswil
CH
|
Family ID: |
34932061 |
Appl. No.: |
11/107641 |
Filed: |
April 15, 2005 |
Current U.S.
Class: |
482/94 |
Current CPC
Class: |
A63B 21/00181 20130101;
A63B 2220/13 20130101; A61H 2201/0192 20130101; A63B 22/0235
20130101; A61H 3/008 20130101; A61H 2201/5061 20130101; A63B
69/0064 20130101; A63B 2022/0094 20130101; A63B 2230/625 20130101;
A63B 71/0009 20130101 |
Class at
Publication: |
482/094 |
International
Class: |
A63B 022/02; A63B
021/06 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 16, 2004 |
EP |
04 405 236.3 |
Claims
1. A device for adjusting the height of and the relief force acting
on a weight, especially on the weight of a patient within a
locomotion training means to be used for walking therapy of
paraparetic or hemiparetic patients, comprising a cable supporting
said weight, a first cable length adjustment means to provide an
adjustment of the length of the cable to define the height of said
suspended weight, a second cable length adjustment means to provide
an adjustment of the length of the cable to define the relief force
acting on the suspended weight, the second cable length adjustment
means comprising an elastic means to provide a counter force to the
suspended weight with a value in the range of the intended relief
force, wherein a bias means is connected in parallel to the elastic
means to preadjust the value of the counter force.
2. The device according to claim 1, characterized in that the first
cable length adjustment means comprises a winch means provided at
one free end of the cable
3. The device according to claim 1, characterized in that the first
cable length adjustment means comprises a movable roller means
provided upstream or downstream to the engagement point of the
second cable length adjustment means
4. The device according to claim 1, characterized in that the first
cable length adjustment means comprises a displacement means for
the second cable length adjustment means.
5. The device according to claim 1, characterized in that the
device furthermore comprises an actuator providing a force parallel
to the direction of the counter force provided by the elastic
means, wherein the addition of the two forces determine the value
of the intended relief force.
6. The device according to claim 5, characterized in that it
further comprises a force transducer connected to a control unit
connected to said actuator to control the relief force.
7. The device according to claim 6, characterized in that the
control unit is a closed loop control unit.
8. The device according to claim 1, characterized in that the bias
means is mounted in parallel with the actuator.
9. A process to adjust the conditions of a weight relieved walking
for a patient, wherein said patient is suspended with help of a
cable supported means, wherein data relating to the height of the
patient and the intended relief force are entered in a control
unit, the control unit activates a first cable length adjustment
means to provide an adjustment of the length of the cable to define
the height of said suspended weight, and the control unit activates
a second cable length adjustment means to provide an adjustment of
the length of the cable to define the relief force acting on the
suspended weight.
10. The process according to claim 9, wherein a force transducer
mounted in series to elastic means of second cable length
adjustment means generates force measurement value of the supported
weight and transmits said values to the control unit being
connected with an actuator of second cable length adjustment means,
wherein the control unit controls the actuator to provide a force
parallel to the direction of the counter force provided by the
elastic means, wherein the addition of the two forces determine the
value of the intended relief force at every moment.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a device and a process for
adjusting the height of and the relief force acting on a weight,
especially on the weight of a patient within a locomotion training
means to be used for walking therapy of paraparetic or hemiparetic
patients. In other words, the invention relates to an automatic
unloading device that allows unloading an object attached to one
end of a rope by a precise counter force. Especially, the invention
relates to a device and a process, which can be used within a
locomotion training of patients with walking impairments in any
phase of rehabilitation.
BACKGROUND OF THE INVENTION
[0002] As mentioned above said type of unloading system can be used
for different applications but is preferably intended for the use
in body weight supported treadmill training. This type of training
is for example being used to train neurologically impaired patients
to walk again during rehabilitation. For such incomplete paraplegic
patients the possibility exists of improving walking ability up to
normality by means of adequate locomotion training. The required
therapy at present takes place on a treadmill, where walking is
first made possible for the patient by defined weight relief and
partially by additional assisting guidance of the legs by
physiotherapists (Wickelgren, I. Teaching the spinal cord to walk.
Science, 1998, 279, 319-321). already in use, which actively move
the legs of recumbent patients. During body weight supported
treadmill training, a patient is walking on a treadmill, while he
is partially suspended from part of his body weight.
[0003] EP 1 137 378 discloses an automatic machine, which is used
in treadmill therapy (walking therapy) of paraparetic and
hemiparetic patients and which automatically guides the legs on the
treadmill. Said machine consists of a driven and controlled
orthotic device, which guides the legs in a physiological pattern
of movement, a treadmill and a relief mechanism. The knee and hip
joints of the orthotic device are each provided with a drive. Said
orthotic device is stabilized on a treadmill with stabilizing means
in such a manner that the patient does not have to keep his/her
equilibrium. The orthotic device can be adjusted in height and can
be adapted to different patients.
[0004] The unloading is achieved by a counterweight that is
attached to the other end of a rope, which is connected to the
patient by a harness. This is by definition a simple method and the
results are often acceptable for regular treadmill training.
However, there are some disadvantages in using this method for this
kind of therapy. One disadvantage is occurring if the patient has
to be suspended by a large amount of his body weight. If a large
mass has to be attached on the other side of the rope the inertia
of the mass is causing large forces during the up and down
acceleration of the body. Also, it is not very easy to change the
amount of unloading during the training with most of the
conventional counterweight systems. Either the therapist has to
lift weight to or from the system to change the suspension or the
patient has to be lifted by a winch to be able to connect
additional counterweights to the system. to change the suspension
or the patient has to be lifted by a winch to be able to connect
additional counterweights to the system.
[0005] Prior art discloses devices to provide a reliable
positioning of the device height, but are cumbersome to adapt to
different patients. Another limitation of this approach is
furthermore the limited liberty of changes to be made in the course
of the application of the walking program for the patient.
[0006] One object of the invention is therefore to describe a
device allowing faster response times and more precise
determination of the height of the patient's position and of the
relief force.
SUMMARY OF THE INVENTION
[0007] The present invention relates on the insight that the
functions of the cable adjustment means have to be separated to be
able to achieve an electronically controlled fast adjustment of the
relief force.
[0008] The set object is met in accordance with the invention by
means of a device in accordance with the wording of claim 1.
[0009] The features according to claim 1 uses two different cable
length adjustment means. One is provided to adjust the length of
the cable to define the height of the suspended weight. The other
is provided to adjust the length of the cable to define the relief
force acting on the suspended weight.
[0010] The invention enhances the control of height and relief
force through the separation of the functions. The height of the
weight depends on the patient, whether he is a tall or a small
person. This is adjusted at the beginning of a training session.
The corresponding device can act slowly, even manually. The relief
force has to be controlled during the actual therapy. The second
cable length adjustment means divides the necessary relief force in
a first static part, providing an approximate force response, and a
second dynamic part, providing the fast fluctuations of the relief
force while the patient is walking.
[0011] Further preferred embodiments of the apparatus according to
the invention are characterized in the dependent claims.
[0012] In order to adapt the principles of the invention to a
larger range of instruments the different devices are motorized and
connected to a computer means with memory, the memory comprising
database entries for different patients (height of suspension and
intended general relief force) and different walking therapies
(fine tuned relief force programs). This allows a quick and
reliable determination and adjustment of the height for different
patients and of the relief force within the training program of
every patient.
[0013] A benefit of the device according to the invention is
therefore that any patient can readily mount the apparatus to use
the treadmill therapy, which is very easy to adjust for his needs.
No special preparation of the treadmill, and no dedicated elastic
means are required.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a perspective view of a device according to one
embodiment of the invention, and
[0015] FIG. 2 shows a schematic diagram of the controller in
combination with the device according to FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0016] FIG. 1 shows a perspective view of a device for adjusting
the height of and relief force acting on a weight according to one
embodiment of the invention.
[0017] The device comprises two main components: one static part 1
and another dynamic part 2. The static component 1 comprises a
winch 10 controlling a primary cable 11 to which the patient is
attached. In the embodiment shown the primary cable 11 fixed at the
turning sleeve of the winch 10 is running preferably parallel to
the longitudinal main axis 20 of the dynamic part 2 of the device.
Said longitudinal main axis 20 is directed vertically to the
ground.
[0018] Cable 11 is redirected by a fixed roller 12 towards the
dynamic part 2 of the device, engages the moving roller 21 being
part of said dynamic part 2 and leaves the dynamic part 2 as
adjusted cable portion 13 of the cable 11. The cable 11 is then
leaving the device redirected by one or more fixed rollers 14; the
corresponding prolongation of the cable 11 has received the
reference numeral 30.
[0019] A patient who intends to use a known apparatus for a
treadmill therapy, e.g. according to EP 1 137 378, is attached in
said prolongation 30 of the cable 11 in a harness (not shown)
oriented vertically. The winch 10 is statically suspending the
patient so he cannot fall and therefore is also responsible for the
safety of the patient per se.
[0020] Although within the preferred shown embodiment of the
invention winch 10 is used to statically adjust the length of cable
11 provided to said harness, it is also possible to fix cable 11 at
the location of the winch 10 and to provide a drive unit connected
to the fixation of a roller upstream of the dynamic part 2, e.g.
roller 12, so that said roller 12 can be moved in direction of
longitudinal axis 20. In another embodiment not shown in the
drawings it can be a roller (or a combination of rollers)
downstream of the dynamic part 2, e.g. roller 14, being mounted
with a drive unit so that said roller(s) 14 can be moved in
direction of longitudinal axis 20 to adjust the length of the cable
11 provided to attach a patient. Within a third embodiment the
static part 1 comprises a unit connected to the frame 32. In said
case the static part 1 does not act directly on the cable. Said
unit is provided to move frame 32 in the direction of longitudinal
axis 20. With a fixed end of cable 11 said movement of frame 32
moves roller 21 and therefore lengthens or shortens the free cable
13.
[0021] All these alternative units for winch 10 can constitute the
static part 1 of the device to provide a static adjustment of the
length of the cable 11 provided in said prolongation 30 which
corresponds to the intended height of the harness for use in a
walking therapy.
[0022] The dynamic part 2 comprises an elastic means. The elastic
means of the embodiment is a spring means 22 provided as two
helicoidal springs provided on either side of a central spindle 23.
Beside the use of helicoidal springs 22 it is also possible to use
different types of elastic means, being able to exert a force in
the approximate range of the intended weight to be attached to the
prolongation 30 of the cable 11.
[0023] Springs 22 are attached between a bottom plate 24 and a top
plate 25. The bottom plate 24 is attached to a spindle drive 31
connected with spindle 23 engaging a thread within bottom plate 24.
Spindle drive 31 shows a handle but can also be motorized and
connected to a control unit. Top plate 25 is connected to a pulley
21, pulling the cable 11 down. Through use of the redirection of
cable portion 13 the rollers 12, 14 and 21 have the function of a
pulley block. It can be intended to use even more redirections to
translate the adjustment of the cable length of the prolongation 30
into a much smaller movement of the pulley 21.
[0024] In parallel with the springs 22, i.e. parallel to the axis
20, there is a linear drive 26 attached to the pulley 21 via the
top plate 25. By this linear drive 26 the force of the springs 22
can be reduced or enhanced. Between the pulley 21 and the dynamic
control component acting on the springs 22 and linear drive 26,
there is a force transducer 27 that measures exactly how much force
is being applied to the rope 13 by the pulley 21. The force
transducer 27, connected in series to elastic means 22, is
connected to a electronic control unit. The control unit is
preferably forming a closed loop control unit.
[0025] The linear drive 26 is controlled by said electronic control
unit, e.g. provided as a computer system, through a closed loop
controller in such a way, that the force acting on the force
transducer 27 can be controlled precisely. The force acting on the
force transducer 27 is mostly directly proportional to the force
acting on cable 13 at the harness. Due to frictional effects the
force can be considerably influenced, especially following the
choice of the material of the rope 13 and/or the pulleys. These
differences from direct proportionality can be controlled through a
programmed controller and/or through introduction of a disturbance
value.
[0026] The force transducer 27 can also be mounted to measure the
force acting on the pulley 14, on the pulley 12 or near the patient
at the other side 30 of the cable 11, being the connecting link to
a harness supporting the patient (weight 40).
[0027] A treadmill training of a neurologically impaired patient
can be performed as follows: First the patient, attached to the
other side 30 of the cable 11 with a harness, would be suspended
over the walking surface by the winch 10 (static unloading system
1) until standing.
[0028] The amount of unloading is defined by the control unit. A
small motor attached to the spindle drive 31 that determines the
tension of the springs 22 would then extend the springs 22 up to a
length that more or less corresponds to the desired unloading of
the patient. Like this the dynamic system is already unloading the
patient nearly with the desired force.
[0029] This closed loop control of body weight support allows for
perfect accommodation of partial weight bearing exercise.
[0030] The up and down movement of the patient causes the force to
be not constant during the training if only the springs 22 were
attached. Therefore the linear drive 26 can adjust the position of
the pulley 21 online, as controlled by the close loop controller,
so the force acting on the rope 11 will be constant, or
corresponding to a desired force trajectory, during the whole
training. Within other embodiments the dynamic drive adds a motor
driven force to the spring force in a manner to compensate the
influence of the position of the device on the spring force due to
friction based effects due to the choice of the material of the
rope and the pulleys.
[0031] The device can only guarantee a precise, desired unloading,
as long as the weight can be adjusted by the linear drive 26. This
is not possible anymore, if the patient moves up or down too much,
meaning that the linear drive 26 is approaching the end of the
range of motion. This is detected by the control unit, as the
movement of the linear drive 26 is measured with a position sensor,
e.g. a ultrasound transducer mounted beneath top plate 25. The
control unit can therefore readjust the position of the patient
with the winch 10 in terms to bring the linear drives 26 back into
the range of operation.
[0032] FIG. 2 shows a schematic diagram of the electronic
controller unit in combination with the device according to FIG. 1.
The winch 10, the actuator 26, e.g. the linear drive, and the bias
means 31, e.g. the spindle drive, are shown receiving an controller
signal I and outputting a signal proportional to a well-defined
force F or position x. The boxes of FIG. 2 showing a actual device
according to FIG. 1 have received the same reference numeral,
although it is clear for someone skilled in the art that the boxes
of FIG. 2 further comprise the electronic controller components to
deliver the control signals mentioned.
[0033] Numeral 40 is used to define the weight of e.g. a human
subject to use the treadmill for which the device for adjusting the
height of and the relief force acting on said weight 40 is
provided. A position sensor 34 (not shown in FIG. 1) measures
X.sub.real and outputs X.sub.measured. The force sensor 27 measures
F.sub.real and outputs F.sub.measured. The (static) position of the
cable x.sub.measured is input to the winch controller 35, acting
via a control signal I.sub.winch on the winch 10 to define the
predetermined height, which can be input to the winch controller 35
via a key means or an electronic signal of said electronic control
unit comprising the walking program for a patient.
[0034] The key means or an electronic signal of said electronic
control unit comprising the walking program for a patient generates
the input F.sub.desired. A mixer 36 is provided to output the
difference signal of F.sub.desired and F.sub.measured. Said
difference signal F.sub.diff is input to a force controller 37
outputting the corresponding control signal I.sub.drive which is
fed to the actuator 26 to dynamically change the length of the
cable 13 to control the force relief.
[0035] F.sub.desired is also the input to the spring load
controller 38, outputting a signal I.sub.springs to bias means 31,
which in turn moves bottom plate 24 to adjust the static weight
compensation by springs 22. The length of the springs 22 is
controlled with the bias means 31 to move the bottom plate 24 into
a position that the tension of the springs 22 is such that patient
is unloaded approximately by the desired force F.sub.desired. The
spring load controller 38 has therefore a far slower response than
the force controller 37.
[0036] In another embodiment of the device according to FIG. 1 a
position sensor 34 (not shown) is provided to directly measure the
length of the springs 22. This can be a position sensor mounted
near top plate 25 measuring the distance of said sensor from bottom
plate 24 or from the element holding pulley 12 or 14. Said position
sensor inputs a spring length signal to the controller as shown in
FIG. 2, especially into block 38 showing the spring load
controller. Additionally the signal issued from position sensor 34
is fed to the force controller 37 to generate a disturbance value.
As mentioned above frictional effects can hamper the usual
proportionality between spring length and load. The additional
feeding of the actual position value to the force controller 37
and/or the spring load controller 38 enables the controller to
adapt the force F.sub.drive. In this respect it is advantageous to
feed F.sub.desired directly to the force controller 37 in order to
have a actual base for the generation of I.sub.drive to generate a
force F.sub.drive adapted to the friction within the whole
device.
* * * * *