title: Classical and adaptive control of ex vivo skeletal muscle contractions using Functional Electrical Stimulation (FES).
abstract: Functional Electrical Stimulation is a promising approach to treat patients by stimulating the peripheral nerves and their corresponding motor neurons using electrical current. This technique helps maintain muscle mass and promote blood flow in the absence of a functioning nervous system. The goal of this work is to control muscle contractions from FES via three different algorithms and assess the most appropriate controller providing effective stimulation of the muscle. An open-loop system and a closed-loop system with three types of model-free feedback controllers were assessed for tracking control of skeletal muscle contractions: a Proportional-Integral (PI) controller, a Model Reference Adaptive Control algorithm, and an Adaptive Augmented PI system. Furthermore, a mathematical model of a muscle-mass-spring system was implemented in simulation to test the open-loop case and closed-loop controllers. These simulations were carried out and then validated through experiments ex vivo. The experiments included muscle contractions following four distinct trajectories: a step, sine, ramp, and square wave. Overall, the closed-loop controllers followed the stimulation trajectories set for all the simulated and tested muscles. When comparing the experimental outcomes of each controller, we concluded that the Adaptive Augmented PI algorithm provided the best closed-loop performance for speed of convergence and disturbance rejection.
authors.affiliation: Department of Weapons and Systems Engineering, United States Naval Academy, Annapolis, Maryland, United States of America.
authors.forename: Paola
authors.identifier: http://orcid.org/0000-0003-4815-3826
authors.initials: P
authors.lastname: Jaramillo Cienfuegos
authors.affiliation: Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America.
authors.forename: Adam
authors.initials: A
authors.lastname: Shoemaker
authors.affiliation: Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Grange
authors.affiliation: Department of Biomedical Engineering and Mechanics, Foods, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America.
authors.forename: Nicole
authors.initials: N
authors.lastname: Abaid
authors.affiliation: Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America.
authors.forename: Alexander
authors.initials: A
authors.lastname: Leonessa
mesh_terms: D000465:Algorithms; D000818:Animals; D004558:Electric Stimulation; D008297:Male; D051379:Mice; D008954:Models, Biological; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*