Patient-driven hybrid FES-exoskeleton control with adaptive band-based assistance

Abstract

Spinal Cord Injuries (SCIs) are a prevalent condition worldwide, leading to a loss of motor function that significantly hinders Activities of Daily Living (ADLs). Optimized rehabilitation is essential to mitigate these challenges, promoting neuroplasticity and motor relearning. One of the most promising approaches combines Functional Electrical Stimulation (FES) of muscles with forces generated by exoskeletons. However, previously developed systems have limitations, particularly in fostering active patient engagement. This proposal introduces a cooperative and Assist-As-Needed hybrid system (FES-EXO) designed for ADL-oriented rehabilitation. The primary objective of the control strategy is to enhance patient performance and independence through a Human-In-The-Loop (HITL) approach. The assistance is dynamically adjusted to the user’sneeds in real time, featuring three operational modes,no assistance, FES-only assistance, and hybrid assistance, based on the user’s motor state. Additionally, the system addresses challenges related to muscle fatigue and insufficient active participation. The proposed control framework will be integrated into the hybrid system and, in future work, will be validated with healthy individuals and, subsequently, with SCI patients in a case study at Guimarães’ Hospital.