Surface Electromyography System for Linear Envelope Detection

Abstract

Surface electromyography (sEMG) serves as a noninvasive method of measuring muscle activity, known for its simplicity of detection and quick acquisition. sEMG finds applications in biomicanic and dynamic analysis of muscle coordination especially, for gait investigation during treadmill and interactive locomotion in human. The analyses of such rhythmic movements mainly cover activity level and/or activation timing, may help medical staff to diagnosis assistance and train specific muscles. The time domain analysis of the sEMG signal requires often the determination of the signal’s envelope. The aim of this paper is first to carry out an sEMG signal acquisition process, followed by the design and implementation of a zero-phase filter in the purpose of detecting the signal’s linear envelope. This feature has the potential to provide an objective, quantitative method for identifying the timing of muscular voluntary contractions to inform the clinical decision-making process. The technique is first analysed and further compared to the conventional filtering, using the MATLAB software, and then was tested with LabVIEW using IX ELVIS NI board.