Development of an upper extremity FES system for individuals with C4 tetraplegia

Abstract

AbstrucG--The application of functional electrical stimulation (FES) to provide upper extremity function for individuals with C4 tetraplegia is under investigation. In this study, a FES system was designed that allowed one individual with complete C4 tetraplegia to coordinate stimulated lateral or palmar prehension with stimulated arm movements using contralateral shoulder position. The system consisted of percutaneous intramuscular electrodes implanted to muscles for hand grasp and release, supination, elbow flexion, and extension and arm adduction. Due to peripheral denervation, transposition and subsequent stimulation of the paralyzed latissimus dorsi muscle provided elbow flexion and transfer and stimulation of the paralyzed extensor carpi ulnaris muscle provided forearm supination. A suspended sling provided shoulder joint stability. The subject controlled stimulation proportionally using contralateral shoulder motion sensed by a position transducer. Control of stimulated hand grasp and release were coupled with stimulated arm motions so that hand-to-mouth activities could be accomplished with one motion of the contralateral shoulder. With this system, the subject was able to grasp a milk carton placed in the hand and lift and lower it from his mouth to drink from a short straw. He could also scoop a semisolid substance with an adapted spoon and lift and lower it from the work surface to his mouth to eat. The subject required assistance to place the milk carton or spoon in his hand and position the plate for scooping. Further investigation is needed to generate the necessary arm movements to make completion of these tasks possible without assistance and to expand the range of activities possible with the FES system.

Evaluation of the lower motor neuron integrity of upper extremity muscles in high level spinal cord injury

“…In both studies, FES, combined with orthotic support at the shoulder, enabled several clients with high tetraplegia to perform simple table top activities such as writing, drinking and eating. Our pilot work on FES and high tetraplegia 23,24 also con®rmed the presence of LMN lesions in muscles innervated at C5 and rea rmed the need for alternative power sources at the elbow and shoulder. We performed a bipolar muscle transfer of the paralyzed but electrically excitable latissimus dorsi to overcome the inability to stimulate the elbow exors.…”

Case study: Head orientation and neck electromyography for cursor control in persons with high cervical tetraplegia

“…The command sources selected for this study, head orientation and neck and face muscle EMG signals, were chosen for testing as user interfaces because they are able to be voluntarily controlled after a high cervical SCI and the movements associated with these actions are generally not directly employed to perform activities of daily living, such as eating, communicating, or grooming [27], minimizing interference with these tasks.…”

Implanted Neuroprosthesis for Restoring Arm and Hand Function in People With High Level Tetraplegia

“…Nathan 12 used voice controlled stimulation of surface electrodes in an elastic sleeve on the extremity, along with splinting and a sling. Betz 13,14 depicted a system using percutaneous electrodes in the arm to provide function for an individual with motor complete C4 spinal cord injury. Control of arm movements was accomplished using voluntary action of the trapezius and levator scapulae of the contralateral shoulder .…”