Technology Transfer of a System for Medically Prescribed F.E.S. Walking Exercise

Abstract

Commercially available electronic muscle stimulators (EMS) are used for functional electrical stimulation (FES) and are interfaced with the reciprocating gait orthoses (RGO). The new system that results is described with both individual electrodes and an electrode garment. Various advantages of the system include: (a) commercially available subsystems from various manufacturers, and (b) subsystems that may be individually prescribed by a physician. The system itself currently employs two EMS units worn on a belt, controlled by remote switches and interfacing to electrodes placed over hamstring and gluteal muscle groups of each leg. Two EMS units (for stimulation of the hip extensors) function primarily for ambulation. The system has been evaluated on four spinal-cord-injured individuals (two paraplegic and two quadriplegic) who are five or more years post-injury. Each EMS unit is powered by a nine-volt alkaline transistor battery. All subjects utilized individual carbon-rubber electrodes, and one subject also utilized a Transcutaneous Transducer Garment (TTG). It is emphasized that successful EMS-RGO walking exercise is one of three modalities in a program of active physical therapy. The paper gives an overview of the operational, design and material considerations that are important for technology transfer.