Application of functional electrical stimulation in paraplegic patients

Abstract

The restoration of lost motor functions after upper motor neuron lesions by functional electrical stimulation (FES) is not a new technique. Early feasibility demonstrations of FES assisted standing and stepping in paraplegics between 1960 and 1980 showed great promise that FES may soon become an effective method to regain upright mobility after spinal cord injury. However, the difficulties encountered have been underestimated. Today, there is a wide gap between FES related research and the clinical application of FES in paraplegic patients. In this paper the scientific literature about FES and its clinical applications is carefully reviewed. The possible reasons for the low clinical relevance of FES and possible solutions for the development of enhanced FES systems are analyzed. Although the functional gain with present FES systems for mobility restoration in paraplegics is relatively low, FES may be beneficial to prevent secondary complications which occur after spinal cord injuries. The development of distributed systems and selective peripheral nerve stimulation techniques, the progress in microelectronics and sensor technology, and the development of nonlinear and closed-loop control strategies give promise for the development of practical and enhanced FES systems that will offer paraplegic patients some additional degrees of freedom.