A Novel sEMG Triggered FES-Hybrid Robotic Lower Limb Rehabilitation System for Stroke Patients

Stroke is a leading cause of acquired disability among adults. Current rehabilitation programs result in only partial recovery of motor ability for the patients, which has resulted in an ongoing search for methods to improve the rehabilitation approaches. Therefore, this study presents a novel method for early onset of active rehabilitation by combining an end effector robot with surface electromyography (sEMG) triggered functional electrical stimulation (FES) of rectus femoris and tibialis anterior muscles. This rehabilitation system was demonstrated in 10 able-bodied experimental participants. Defining a successful exercise repetition as a fully completed exercise, from start point to end point followed by a return to start point, when FES onset is triggered by the EMG threshold, the results showed that 97% of the exercise repetitions were successful for a leg press exercise and 100% for a dorsiflexion exercise. Furthermore, an FES stimulation current amplitude of 20–53 mA was required for the leg press exercise and 10–30 mA for the dorsiflexion exercise. The resulting generated force was in the range of 43.0-141.2 [N] for the leg press exercise and 5.4-17.6 [N] for dorsiflexion.