A Muscle Synergy-inspired Adaptive Control Scheme for a Hybrid Walking Neuroprosthesis

Abstract--- Abstract--- A hybrid neuroprosthesis that uses an electric motor-based wearable exoskeleton and functional electrical stimulation (FES) has a promising potential to restore walking in persons with paraplegia. A hybrid actuation structure introduces effector redundancy, making its automat...

Full description

Bibliographic Details
Main Authors: Naji A Alibeji, Nicholas Andrew Kirsch, Nitin eSharma
Format: Article
Language:English
Published: Frontiers Media S.A. 2015-12-01
Series:Frontiers in Bioengineering and Biotechnology
Subjects:
Online Access:http://journal.frontiersin.org/Journal/10.3389/fbioe.2015.00203/full
_version_ 1818602060080218112
author Naji A Alibeji
Nicholas Andrew Kirsch
Nitin eSharma
author_facet Naji A Alibeji
Nicholas Andrew Kirsch
Nitin eSharma
author_sort Naji A Alibeji
collection DOAJ
description Abstract--- Abstract--- A hybrid neuroprosthesis that uses an electric motor-based wearable exoskeleton and functional electrical stimulation (FES) has a promising potential to restore walking in persons with paraplegia. A hybrid actuation structure introduces effector redundancy, making its automatic control a challenging task because multiple muscles and additional electric motor need to be coordinated. Inspired by the muscle synergy principle, we designed a low dimensional controller to control multiple effectors: FES of multiple muscles and electric motors. The resulting control system may be less complex and easier to control. To obtain the muscle synergy-inspired low dimensional control, a subject-specific gait model was optimized to compute optimal control signals for the multiple effectors. The optimal control signals were then dimensionally reduced by using principal component analysis to extract synergies. Then, an adaptive feedforward controller with an update law for the synergy activation was designed. In addition, feedback control was used to provide stability and robustness to the control design. The adaptive-feedforward and feedback control structure makes the low dimensional controller more robust to disturbances and variations in the model parameters and may help to compensate for other time-varying phenomena (e.g., muscle fatigue). This is proven by using a Lyapunov stability analysis, which yielded semi-global uniformly ultimately bounded tracking. Computer simulations were performed to test the new controller on a 4 degree of freedom gait model.
first_indexed 2024-12-16T13:01:16Z
format Article
id doaj.art-6344d0374d0b4334ae604ef99235fe36
institution Directory Open Access Journal
issn 2296-4185
language English
last_indexed 2024-12-16T13:01:16Z
publishDate 2015-12-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Bioengineering and Biotechnology
spelling doaj.art-6344d0374d0b4334ae604ef99235fe362022-12-21T22:30:50ZengFrontiers Media S.A.Frontiers in Bioengineering and Biotechnology2296-41852015-12-01310.3389/fbioe.2015.00203152938A Muscle Synergy-inspired Adaptive Control Scheme for a Hybrid Walking NeuroprosthesisNaji A Alibeji0Nicholas Andrew Kirsch1Nitin eSharma2University of PittsburghUniversity of PittsburghUniversity of PittsburghAbstract--- Abstract--- A hybrid neuroprosthesis that uses an electric motor-based wearable exoskeleton and functional electrical stimulation (FES) has a promising potential to restore walking in persons with paraplegia. A hybrid actuation structure introduces effector redundancy, making its automatic control a challenging task because multiple muscles and additional electric motor need to be coordinated. Inspired by the muscle synergy principle, we designed a low dimensional controller to control multiple effectors: FES of multiple muscles and electric motors. The resulting control system may be less complex and easier to control. To obtain the muscle synergy-inspired low dimensional control, a subject-specific gait model was optimized to compute optimal control signals for the multiple effectors. The optimal control signals were then dimensionally reduced by using principal component analysis to extract synergies. Then, an adaptive feedforward controller with an update law for the synergy activation was designed. In addition, feedback control was used to provide stability and robustness to the control design. The adaptive-feedforward and feedback control structure makes the low dimensional controller more robust to disturbances and variations in the model parameters and may help to compensate for other time-varying phenomena (e.g., muscle fatigue). This is proven by using a Lyapunov stability analysis, which yielded semi-global uniformly ultimately bounded tracking. Computer simulations were performed to test the new controller on a 4 degree of freedom gait model.http://journal.frontiersin.org/Journal/10.3389/fbioe.2015.00203/fullFunctional Electrical Stimulation (FES)Adaptive controlNonlinear ControlHybrid neuroprosthesisTime-Invariant Synergies
spellingShingle Naji A Alibeji
Nicholas Andrew Kirsch
Nitin eSharma
A Muscle Synergy-inspired Adaptive Control Scheme for a Hybrid Walking Neuroprosthesis
Frontiers in Bioengineering and Biotechnology
Functional Electrical Stimulation (FES)
Adaptive control
Nonlinear Control
Hybrid neuroprosthesis
Time-Invariant Synergies
title A Muscle Synergy-inspired Adaptive Control Scheme for a Hybrid Walking Neuroprosthesis
title_full A Muscle Synergy-inspired Adaptive Control Scheme for a Hybrid Walking Neuroprosthesis
title_fullStr A Muscle Synergy-inspired Adaptive Control Scheme for a Hybrid Walking Neuroprosthesis
title_full_unstemmed A Muscle Synergy-inspired Adaptive Control Scheme for a Hybrid Walking Neuroprosthesis
title_short A Muscle Synergy-inspired Adaptive Control Scheme for a Hybrid Walking Neuroprosthesis
title_sort muscle synergy inspired adaptive control scheme for a hybrid walking neuroprosthesis
topic Functional Electrical Stimulation (FES)
Adaptive control
Nonlinear Control
Hybrid neuroprosthesis
Time-Invariant Synergies
url http://journal.frontiersin.org/Journal/10.3389/fbioe.2015.00203/full
work_keys_str_mv AT najiaalibeji amusclesynergyinspiredadaptivecontrolschemeforahybridwalkingneuroprosthesis
AT nicholasandrewkirsch amusclesynergyinspiredadaptivecontrolschemeforahybridwalkingneuroprosthesis
AT nitinesharma amusclesynergyinspiredadaptivecontrolschemeforahybridwalkingneuroprosthesis
AT najiaalibeji musclesynergyinspiredadaptivecontrolschemeforahybridwalkingneuroprosthesis
AT nicholasandrewkirsch musclesynergyinspiredadaptivecontrolschemeforahybridwalkingneuroprosthesis
AT nitinesharma musclesynergyinspiredadaptivecontrolschemeforahybridwalkingneuroprosthesis