Classification of ankle joint movements based on surface electromyography signals for rehabilitation robot applications

Med Biol Eng Comput. 2017 May;55(5):747-758. doi: 10.1007/s11517-016-1551-4. Epub 2016 Aug 2.

Abstract

Electromyography (EMG)-based control is the core of prostheses, orthoses, and other rehabilitation devices in recent research. Nonetheless, EMG is difficult to use as a control signal given the complex nature of the signal. To overcome this problem, the researchers employed a pattern recognition technique. EMG pattern recognition mainly involves four stages: signal detection, preprocessing feature extraction, dimensionality reduction, and classification. In particular, the success of any pattern recognition technique depends on the feature extraction stage. In this study, a modified time-domain features set and logarithmic transferred time-domain features (LTD) were evaluated and compared with other traditional time-domain features set (TTD). Three classifiers were employed to assess the two feature sets, namely linear discriminant analysis (LDA), k nearest neighborhood, and Naïve Bayes. Results indicated the superiority of the new time-domain feature set LTD, on conventional time-domain features TTD with the average classification accuracy of 97.23 %. In addition, the LDA classifier outperformed the other two classifiers considered in this study.

Keywords: Ankle joint movements; EMG; Pattern recognition; Rehabilitation; Signal processing.

MeSH terms

  • Adult
  • Algorithms
  • Ankle Joint / physiology*
  • Bayes Theorem
  • Discriminant Analysis
  • Electromyography / methods
  • Female
  • Humans
  • Male
  • Movement / physiology*
  • Pattern Recognition, Automated / methods
  • Prostheses and Implants
  • Robotics / methods
  • Signal Processing, Computer-Assisted