Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to convalescent aids, and
particularly to physical therapy devices such as exercise
walkers or physical therapy walkers. While the invention is
disclosed in the context of a convalescing human patient, it is
to be understood that the invention may find equal utility as
an aid to a convalescing animal such as, for example, a horse
with a leg injury.
Various types of convalescent walkers or physical
therapy walkers and related types of apparatus are known. ~y
way of example, but not intended to be an exhaustive listing
of the prior art in this field, there are the following United
States patents: 2,327,671; 2,812,010; 2,871,915; 3,730,587;
4,164,350; and 4,256,098. While these patents do provide some
general guidance in the construction and use of mechanisms of
this general type, they do not provide many forms of control
over several aspects of convalescence, such as, for example,
the amount of a convalescing patient's own weight the patient
bears during a physical therapy session, and the time or distance
the convalescing patient is to walk during a particular physical
therapy session.
According to one aspect, the invention provides a
physical therapy device comprising a supporting column, an arm,
means for rotatable and pivotally mounting the arm from the
column, a harness, means for suspending the harness from the arm,
the means for suspending the harness from the arm including an
electrically powered hoist, a cable trained about the hoist and
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coupled to the harness, and means for mounting the hoist from the
arm, a walkway extending around the supporting column and defined
generally beneath the harness as the arm moves about its
rotational mounting to the supporting column, means for detect-
ing the load exerted by a convalescing patient on the harness
and means for mounting the load detecting means between the har-
ness and the arm, a programmable machine for controlling the
physical therapy device, the programmable machine provided with
an input port, and means for coupling the load detecting means
to the input port.
The invention also provides a physical therapy
device comprising a supporting column, an arm, a means for rotat-
ably and pivotally mounting the arm from the column, a hoist,
~eans for mounting the hoist on the arm, a harness, means for
suspending the harness from the hoist, a walkway extending around
the supporting column and defined generally beneath the harness
as the arm moves about its rotation mounting to the supporting
column, means for mounting the hoist adjacent one end of the arm,
a sheave, means for mounting the sheave adjacent the other end
of the arm, the means for suspending the harness from the hoist
including a cable extending over the sheave between the harness
and the hoist, the means for rotatably and pivotally mounting the
arm from the column comprising a yoke, means for rotatably moun-
ting the yoke from the column, and means for pivotally mounting
the arm from the yoke, a counterbalance means for mounting the
: counterbalance from one of the yoke and arm to suspend a portion
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of the weight of a patient in the harness, means for detecting
the load exerted by a convalescing patient on the harness, and
means for mounting the load-detecting means between the arm and
the hoist.
The apparatus may further comprise a brake and
means for mounting the brake on the supporting column. The brake
brakes relative motion between the arm and the supporting column.
The means for rotatably and pivotally mounting the
arm from the supporting column may comprise a yoke, means for
rotatably mounting the yoke from the supporting column, and
means for pivotally mounting the arm from the yoke. The axis of
rotation of the yoke on the supporting column ana the pivotal
axis of the arm on the yoke are generally orthogonal to each
other.
The means for detecting the load exerted by the
convalescing patient on the harness may comprise a load cell.
The invention may best be understood by referring
to the following description and accompanying drawings which
illustrate the invention. In the drawings:
Figure 1 illustrates a side elevational view of
an apparatus constructed according to the present invention;
Figure 2 illustrates a top plan view of the appara-
tus of Figure l; and
Figure 3 illustrates a block diagram of the
electrical system for operating the apparatus of Figures 1-2.
. ,)
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Referring particularly to Figures 1-2, the
physical therapy device, or convalescent walker 10 includes
a supporting column 12 which extends generally vertically and
is maintained in vertical orientation by four equally-spaced
radially outwardly and axially downwardly extending legs 14.
Column 12 and legs 14 are mounted on a foot 16 which can be
cross-shaped, circular or of any other suitable shape. llhe
column 12 is capped
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by a yoke 18 which is rotatably mounted on the top 20 of
the column 12 about a vertical axis extending through
column 12. Yoke 18 includes upwardly extending gudgeons
22. A pivot pin 24 extends horizontally through aligned
apertures in gudgeons 22 and in a generally horizontally
extending arm 26 positioned between the gudgeons 22. A
support 28 extends outward from the yoke 18 in the
direction of the longer extent 30 of arm 26. Support 28
supports an air counterbalance 32 which can be an
inflatable air bag or compressed air-driven shock
absorber type mechanism. The air counterbalance 32 acts
between the support 28 and an attachment point 34 on the
underside of the longer extent 30 of arm 26. By
regulating the air pressure in the air counterbalance
32, the patient supported from the distal end 36 of arm
26 is more or less supported by the air counterbalance
32.
A small electric motorized hoist 38 is mounted
at the distal end 40 of the shorter extent 42 of arm
26. The mounting of the hoist 38 is by means of a
hinge, the axis of which is generally parallel to the
axis of the pivot pin 24. This permits pivoting of the
hoist 38 about an axis generally perpendicular to the
longitudinal extent of arm 26. A mounting bracket 44 is
attached to the leaf of the hinge to which hoist 38 is
attached. The other leaf of the hinge is attached to
the distal end 40 of the shorter extent 42 of arm 26.. A
similar mounting bracket 46 is attached to the underside
of the shorter extent 42 of arm 26 in close proximity to
mounting bracket 44. A load cell 48 is positioned
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between brackets 44, 46 so that the load on the hoist 38
is transmitted to the load cell 48 and results in the
load cell 48 providing an electrical signal indicative
of the load on the ca~le 50 wound on hoist 38. The
cable 50 extends along the length of the arm 26 to a
sheave 52 which is pivotally mounted at 54 adjacent end
36 of arm 26.
Cable 50 is terminated by a hook 58 which is
adapted to engage an eye provided on a harness 60 for
supporting the recuperating patient 62. Rotation of the
arm 26 about the pivot axis of the yoke 18 and column 12
(generally the center line of column 12) causes the
harness 60 to trace a circular path 64 on the surface
upon which column 12 stands. This circular path 64 is
bounded by vertically adjustable inner and outer
circular handrails 66, the outer handrail of which is
provided with access gates 68. The handrails 66 are
supported upon stanchions 70 which are mounted to the
surface upon which column 12 stands, typically by
threaded fasteners through flanges provided at the feet
of the stanchions 70.
A support 72 extends outward from the distal
end 36 of arm 26 and supports a pendent control housing
- 74 in the area of the convalescing patient's hand. A
brake 76, which may be controlled by spring, compressed
air or electricity, is mounted between the column 12 and
the yoke 18 to control the rate of rotation of arm 26
about the axis of column 12.
Turning now to Fig. 3, electrical power is
supplied from, for example, a 115 VAC, 60 Hz line to a
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power supply 80. Power at appropriate voltages and
currents is supplied from supply 80 to the hoist 38 and
to an air compressor 82 which provides compressed air
through a filter 84 to two regulators 86, 88.
Compressed air is provided from regulator 86 to operate
the brake 76, where the brake is an air-operated brake.
Compressed air from regulator 88 is provided to the air
counterbalance 32. Power is also supplied from power
supply 80 to a computer 90 which operates the system
illustrated in Figs. 1-2. Illustratively, the computer
90 is one of the commercially available personal-type
computers, such as a Tandy TRS80 Model 102 or
equivalent. The computer 90, along with power supply
80, compressor 82, filter 84 and regulators 86, 88 can
be housed within a control cabinet 92 mounted on yoke 18
(Figs. 1-2).
Input/output signals to/from the computer 90
are provided by/to the air counterbalance 32, the
compressor 82, the brake 76, the hoist 38, the load cell
48, switch 56 and air regulators 86, 88. An additional
input to the computer 90 is provided by an odometer 94
which counts the rotations and partial rotations of arm
26 about the pivot axis of column 12. The odometer 94
provides a "distance traveled~ input signal to computer
90. Computer 90 also receives input signals from, and
provides output signals to, controls in the pendent
control housing 74. ~ypically these signals include the
amount or percentage of the patient's weight being
supported by the system 10, an elapsed exercise time or
an odometer reading, "hoist up" and ~hoist down~ signals
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indicating the operating status of hoist 38, ASCII, or
other machine-readable, characters which instruct the
computer, for example, to indicate the amount or
percentage of the patient's weight the patient is to
bear during a physical therapy session, and commands to
a printer to cause it to print such information as the
duration, either in time or in distance traveled, of a
physical therapy session, the amount or percentage of a
patient's weight the patient bore during the physical
therapy session, the patient's name and/or other
identifying information, and the like.
It will be immediately appreciated that the
apparatus of the present invention will permit
substantial labor savings in the physical therapy
department of a hospital, for example, as well as
increasing safety by reducing the likelihood of a
recuperating patient falling. This apparatus also
permits the attending physician to have much greater
control over the recuperating patient's physical
therapy, by permitting the physician to select not only
the distance or time the patient walks, but also, the
amount or percentage of the patient's weight that the
patient must bear during physical therapy sessions.
The circular path 64 between handrails 66 is
also wide enough that a conventional walker can be
placed in the path 64 for the patient to use during
physical therapy in order to learn how to use the
walker. The controls on the control housing 74 permit
the physical therapist to set the distance or time to be
walked, and the amount of the patient's total weight
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that the patient is to bear during the physical therapy
session. After the distance is traveled or the time has
elapsed, an alarm sounds so that the therapist can
attend to, for example, transferring the patient back to
a wheelchair to be returned to his or her room. The
brake 76 permits the patient to walk at his or her own
pace, while still providing stability.
In addition to adjusting the amount of the
patient's weight that the patient is to bear during a
physical therapy session, the hoist 38 can be used to
hoist the pa~ient from, and return the patient to, a
wheelchair. The computer 90 permits rapid set-up of the
system, and the printer in the control cabinet 92
produces a printout of the conditions the patient has
endured during therapy, as well as other information,
such as a patient name, patient identification number,
the amount of time and/or distance the patient walked,
the amount or percentage of the patient's own weight
that the patient bore during the therapy session, the
patient's average walking speed during the therapy
session and so on.
In operation, the switch 56 starts the
compressor 82 and causes a red light to come on on the
control cabinet 92 until the output air pressure of the
compressor 82 reaches a safe operating range. If during
the therapy session the compressor output pressure falls
outside the safe operating range, the red light again
comes on until the pressure is back within the safe
operating range. The attending therapist or nurse
3~ secures the patient in the harness 60 and attaches the
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harness 60 by hook 58 to the cable 50 and hoist 38. The
hoist 38 cannot be energized through the switch 56 until
the air compressor safe operating range is achieved. At
that time, the computer 90 qenerates a menu on the
computer display in housing 74 that leads the therapist
step-by-step through entry of the required data, such as
patient name, patient identification number, patient's
approximate weight (for operation of the brake 76),
amount or percentage of patient's body weight to be
supported by the air counterbalance 32, time or distance
the patient is to walk, and the like. Then the patient
is raised by operation of the hoist 38 and the treatment
begins. After treatment is completed, the patient is
lowered to the waiting wheelc~air and the attending
therapist depresses a "print" button on the control
housing 74. The computer 90 causes all information
pertinent to the recuperating patient's medical record
to be printed by the printer in the control cabinet 92.
