An alternating controlled functional electrical stimulation strategy based on sample entropy for rehabilitation of lower extremity hemiplegia

In this study, we present an alternating controlled functional electrical stimulation (FES) strategy for rehabilitation of lower extremity motor function of hemiplegia after stroke. The muscle activity onset time, determined by using sample entropy (SampEn) analysis of an electromyographic (EMG) signal, is used as a trigger for FES to manage stimulations. The EMG-bridge (EMGB) type FES is a novel motor functional rehabilitation idea that it exploits sEMG signal from a healthy limb to regulate the stimulus parameters of stimulations applied to the paralyzed limb, so as to achieve synchronous movement of bilateral or different limbs. The alternating controlled FES strategy was realized on the basis of combing muscle activity onset time with EMGB-type FES system. Using this FES control strategy, experiments on a healthy subject have been carried out successfully to realize alternating stimulation to plantar flexor (PF) and dorsiflexor (DF) muscles of lower limb in sitting position.