A Test of Stimulation Schedules for the Cycle-to-Cycle Control of Multi-joint Movements in Swing Phase of FES-induced Hemiplegic Gait

Abstract

This paper described a computer simulation test of six different stimulation schedules for the cycle-to-cycle control of swing phase of functional electrical stimulation (FES) induced hemiplegic gait. The stimulation schedules were evaluated in controlling the hip, the knee and the ankle joint movements on the point of view of acceptable quality of the gait that was similar to the natural gait pattern. Five stimulation schedules were knowledge-based stimulation schedules and one stimulation schedule was an EMG-based stimulation schedule. Two acceptable stimulation schedules were found by the evaluation. Results of this study showed that combination of the timing pattern of muscle activation and knowledge of joint movements and muscle function is necessary in design of stimulation schedule for FES gait. Co-activation of the ilopsoas, the hamstrings and the vastus muscle at the beginning of swing phase and that of the tibialis anterior and the soleus at the end of swing phase were found to be effective in controlling swing phase. The knowledge-based generation of stimulation schedule would be effective and necessary in clinical application.