An Examination of Stimulation Timing Patterns for Mobile FES Cycling Under Closed-Loop Control of Low Cycling Speed

Pedaling wheelchair can be effective in rehabilitation training of lower limbs of paralyzed subjects by combination with functional electrical stimulation (FES). Since FES cycling training with cycling ergometer suggested that different effects were obtained under different cycling speeds, control of cycling speed is required for mobile FES cycling system in its use at rehabilitation. In this paper, closed-loop control of low cycling speed (0.2 m/s) of the mobile FES cycling was examined with 3 neurologically intact subjects, because a preliminary test of closed-loop control of low speed cycling showed backward propulsion. Two stimulation timing patterns based on EMG signals measured under different cycling speeds were tested in the closed-loop control. The stimulation timing pattern based on muscle activation timing measured under the cycling speed near the target speed was suggested to be effective.