EMG-based Co-Contraction Controller for an Upper-Limb Exoskeleton

Neuromotor impairments resulting from conditions such as stroke significantly challenge individuals and healthcare systems, necessitating the development of effective rehabilitation techniques. This paper explores the application of a co-contraction control scheme for the elbow flexion and extension movement in a 3 Degrees of Freedom (DoF) upper limb exoskeleton, aimed at improving neuromotor rehabilitation outcomes. Utilizing surface electromyography (sEMG) as a control interface, the co-contraction strategy enables modulation of movement velocity based on real-time muscle activity. The control was simulated on sEMG data obtained from 8 patients after 10 weeks of upper limb robotic rehabilitation. Results indicated that the co-contraction control facilitated smoother and more controlled movements compared to traditional threshold-based control. Findings suggest that this control scheme could significantly improve patient engagement and enable more active participation of the patients during rehabilitation.