Switched tracking control of the lower limb during asynchronous neuromuscular electrical stimulation: Theory and experiments

Ryan J. Downey*, Teng-Hu Cheng, Matthew J. Bellman, Warren E. Dixon

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

Neuromuscular electrical stimulation (NMES) induces muscle contractions via electrical stimuli. NMES can be used for rehabilitation and to enable functional movements; however, a fundamental limitation is the early onset of fatigue. Asynchronous stimulation is a method that can reduce fatigue by utilizing multiple stimulation channels to segregate and switch between different sets of recruited motor units. However, switching between stimulation channels is challenging due to each channel's differing response to stimulation. To address this challenge, a switched systems analysis is used in the present work to design a controller that allows for instantaneous switching between stimulation channels. The developed controller yields semi-global exponential tracking of a desired angular trajectory for a person's knee-joint. Experiments were conducted in six able-bodied individuals. Compared to conventional stimulation, the results indicate that asynchronous stimulation with the developed controller yields longer durations of successful tracking despite different responses between the stimulation channels.

Original languageEnglish
Article number7446312
Pages (from-to)1251-1262
Number of pages12
JournalIEEE Transactions on Cybernetics
Volume47
Issue number5
DOIs
StatePublished - 1 May 2017

Keywords

  • Asynchronous stimulation
  • fatigue
  • functional electrical stimulation (FES)
  • neuromuscular electrical stimulation (NMES)
  • nonlinear control
  • switched systems

Fingerprint Dive into the research topics of 'Switched tracking control of the lower limb during asynchronous neuromuscular electrical stimulation: Theory and experiments'. Together they form a unique fingerprint.

Cite this