title: Feedback Error Learning Controller for Functional Electrical Stimulation Assistance in a Hybrid Robotic System for Reaching Rehabilitation.
abstract: Hybrid robotic systems represent a novel research field, where functional electrical stimulation (FES) is combined with a robotic device for rehabilitation of motor impairment. Under this approach, the design of robust FES controllers still remains an open challenge. In this work, we aimed at developing a learning FES controller to assist in the performance of reaching movements in a simple hybrid robotic system setting. We implemented a Feedback Error Learning (FEL) control strategy consisting of a feedback PID controller and a feedforward controller based on a neural network. A passive exoskeleton complemented the FES controller by compensating the effects of gravity. We carried out experiments with healthy subjects to validate the performance of the system. Results show that the FEL control strategy is able to adjust the FES intensity to track the desired trajectory accurately without the need of a previous mathematical model.
authors.affiliation: Neural Rehabilitation Group, Cajal Institute , Spanish National Research Council (CSIC), Madrid, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Resquín
authors.affiliation: Neural Rehabilitation Group, Cajal Institute , Spanish National Research Council (CSIC), Madrid, Spain.
authors.forename: Jose
authors.initials: J
authors.lastname: Gonzalez-Vargas
authors.affiliation: Neural Rehabilitation Group, Cajal Institute , Spanish National Research Council (CSIC), Madrid, Spain.
authors.forename: Jaime
authors.initials: J
authors.lastname: Ibáñez
authors.affiliation: Catholic University . Asunción, Paraguay.
authors.forename: Fernando
authors.initials: F
authors.lastname: Brunetti
authors.affiliation: Neural Rehabilitation Group, Cajal Institute , Spanish National Research Council (CSIC), Madrid, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Pons
keywords: feedback error learning; functional electrical stimulation; hybrid robotic system; stroke; upper limb rehabilitation