Wright State University

Jerrold S Petrofsky

Roger M Glaser

Chandler A Phillips

Harry H Heaton, Iii

Steven H Petrofsky

Howard R DuFour

Roy D Douglas

Paul F Larson

A system for assisting contraction of a partially paralyzed muscle. The system uses a pair of electrode terminals which sense voluntary EMG signals at the site of the muscle and periodically transmit appropriately corresponding higher level stimulation signals. Stimulation signals are generated by a pulsed stimulator operating under control of an amplifier arrangement connected to receive the EMG signals from the electrode terminals. A transistor switch interrupts the amplifier output in synchronism with the generation of stimulation signals. A pair of back-to-back diodes are positioned between the electrode terminals for limiting the signals which are applied to the amplifier.

Apparatus for assisting muscular contraction

Method for assisting in the maintenance of a balanced stance by a person who has lost the sense of touch in one or both feet. Load signals are generated in correspondence with body weight loads applied at forward and rearward portions of the feet. The load signals are used for creation of tactile stimuli in a spaced pattern on a sensitive skin area of the person.

Method for balancing assistance

A system for controlling the movement of a human knee joint during stimulated flexion thereof. The system includes a brace having an over-center hinge at the knee joint. This hinge causes the knee joint to lock under load when the hinge is opened less than a predetermined angle. A sensor senses the angle of opening of the hinge joint and generates a corresponding sensing signal for use by a computer connected for controlling the stimulation of the knee. The computer is programmed for avoiding increases in the stimulation signal when the hinge joint has an angle of opening which is less than some predetermined angle greater than zero and not greater than the critical angle of the hinge.

Control system for knee joint

A walking assistance system comprising a pair of reciprocating braces and computer controlled stimulation electrodes for stimulating alternating extension of the left and right hips of an assisted person. The braces include left and right leg portions which are interconnected by cables in such a manner as to produce forward motion of either leg when the weight of the person is resting on the opposite leg and the hip of the weight bearing leg is stimulated into extension. The braces are equipped with knee locks which may be unlocked to permit assumption of a sitting position. The cables are also operatively disengaged during sitting.

Walking assistance system

A computer control system which allows precise control of movement in paralyzed muscle through functional electrical stimulation. The system includes a computer operated at a programming center under physician control, an electronically erasable and programmable read only memory removable cartridge and a remotely located second computer for controlling the operation of appropriately configured exercise equipment. By using this system, a physician can set work limits for a patient, and the patient can then exercise essentially under a physician's control but without the physician's direct and continuous supervision. In a preferred embodiment, records of the intensity and length of the workout are kept on the cartridge so that the physician can recall the data and get a graphical printout from the computer.

Method and apparatus for providing stimulated exercise of paralyzed limbs

Apparatus and method for stimulating muscular activity in an acutely injured patient. A leg which is to be stimulated is strapped into a brace, and the leg muscles are stimulated to work isometrically against the brace. The effort exerted by the muscles is measured by load cells which generate feedback signals for a control computer. The computer adjusts the stimulation signals in accordance with the received feedback signals.

Therapy system for acute patient care

A system for stimulating a grasping action by a paralyzed hand. The system includes a sensor arrangement for detecting movement of a shoulder by the paralyzed person. The sensor transmits shoulder movement signals to a computerized controller which generates stimulation signals for stimulation electrodes mounted within a cuff worn about the forearm which supports the hand to be stimulated. Closed loop control is accomplished by use of a glove to which are attached a length sensor and a pressure sensor connected for alternative selection. Stimulation of deeply buried muscles is accomplished by arranging the stimulation electrodes into side-by-side electrode sets which are so positioned as to produce focusing of stimulation energy at the location of the subject muscle.

Apparatus and method for muscle stimulation

A therapeutic device for reversing osteoporosis in human limbs which comprises a crank assembly adapted to attach to the distal ends of a pair of human limbs such as the legs, a motor for rotating the crank assembly so that the limbs move along a predetermined path, a vibrator for vibrating the crank assembly, thereby transmitting vibrations to the limbs, and a control for regulating the amplitude of the vibrations transmitted to the limbs. In a preferred embodiment, the control includes an accelerometer adapted to be mounted on a supported limb to generate a signal proportional to the amplitude of the vibrations actually felt by the limbs. The signal is used to modify the amplitude of electric current generated by the control to power the vibrator such that the amplitude of driving vibrations generated by the vibrator is proportional to the amplitude of vibrations felt by the limbs so that the amount of vibration of the limbs is maintained within a predetermined range.

Therapeutic device

A computer algorithm and hardware are disclosed for feedback control of movement in man for standing and walking. The system measures motion of the hips, knees and ankles and generates control signals for ten different muscle groups. Hip and knee supports are provided for restricting hip and knee movement to a common plane.

Feedback control system for walking

Hand control system

An exercising method and apparatus for use in the treatment of paralyzed muscles. The method and apparatus make use of a set of transcutaneous electrodes which are placed upon the skin of the subject over muscles which are to be stimulated. A computer controlled stimulator generates a pair of alternately pulsed stimulation signals which are applied across different pairs of stimulation electrodes to produce controlled muscle contraction. Muscle movement is resisted by a dynamic load, and a position sensor provides a feedback signal indicating the movement actually achieved. The computer uses the feedback signal for modifying the control signal applied to the stimulator. The exercise routine is disclosed as being conducted upon the leg of a subject seated in a specially designed exercise chair.

Method and apparatus for exercising

A wheelchair includes a chassis, a pair of side wheels for supporting and driving the chassis, at least one front wheel for cooperating with the side wheels in supporting the chassis, and a seat mounted on the chassis for supporting the body of a disabled person. A pair of individually moveable footrests support the feet of the person. A driving gear is mounted for rotation concentrically and in conjunction with each of the side wheels, and a lever is pivotally mounted for rotation concentric with but independent from each of the driving gears. A pawl is mounted on each of the levers for engagement and disengagement with the corresponding driving gear. A pivoted arm and a series of rods connect each lever and pawl with one of the footrests, such that movement of the footrest by the leg of the disabled person in one direction causes the pawl to engage the driving gear and the lever to drive the gear for propelling the wheelchair. Movement of the footrest in the opposite direction causes the pawl to disengage and the lever to return to its original position. The disclosed wheelchair may be adapted such that the legs of a paralyzed individual can propel the chair through use of electrical muscle stimulation.

Wheelchair and drive system therefor

Apparatus and method for therapeutic treatment of persons having paralyzed legs. The apparatus and method make use of four sets of transcutaneous electrodes which are placed above the iliac and quadriceps muscles of the paralyzed person. The person is seated upon an exercycle, and a series of pulsed stimulation signals are applied to the electrodes to cause coordinated contraction of the iliac and quadriceps muscles. This causes pedaling of the exercycle by the paralyzed legs. A position sensor senses the position of the pedals and transmits an indication thereof to a computer which generates control signals for stimulation driving circuits connected to the stimulation electrodes. A pair of paddle controllers are connected to the computer for manual adjustment of the stimulation amplitude.

System and method for treating paralyzed persons

A method and apparatus for stimulating a human muscle to produce a controlled response against a dynamic load. Muscle stimulation is achieved through a pair of alternately pulsed stimulation signals which are applied across different pairs of stimulation electrodes. A pulse generating circuit generates the pulsed stimulating signals at a frequency of about 60 Hz across each electrode pair. A position sensor provides a feedback signal to a computer, which in turn generates a stimulation control signal. The pulse generating circuit uses the stimulation control signal for adjusting the amplitude of the stimulation pulses. The pulse width of the stimulation pulses is disclosed as being about 500 microseconds.

Growing community of inventors

Beavercreek, OH, United States of America

Jerrold S Petrofsky