sEMG signal filtering study using synchrosqueezing wavelet transform with differential evolution optimized threshold

Abstract

Most gesture recognition studies based on surface electromyography (sEMG) signals focus on filtering, in which the lack of diversity for considered noises can still be the problem. In this work, a denoising method based on Synchrosqueezing Wavelet Transform with Differential Evolution optimized threshold (DEOT-SWT) is proposed. The sEMG signals of ten gestures with three mixed noises, including power line interference (PLI), baseline drift (BW), and white Gaussian noise (WGN), are firstly investigated and filtered by DEOT-SWT, which are collected from seven subjects by utilizing two wearable sEMG signal sensors. Then, the most commonly used Hudgins time-domain feature set is extracted for recognizing ten gestures. Three metrics are adopted to evaluate filtering performance: signal-to-noise ratio (SNR), root mean square error and R-squared value. The gesture recognition accuracy is utilized to verify the practical effect of DEOT-SWT in sEMG-based gesture recognition applications. The results of the experiments demonstrate that the DEOT-SWT algorithm accomplishes desirable denoising performance with an average recognition accuracy of 95.95% (±3.88) in comparison to the classic Infinite Impulse Response (IIR) algorithm and the empirical mode decomposition (EMD) algorithm.

Keywords

• Surface electromyography signals denoising
• Synchrosqueezing wavelet transform
• Differential evolution
• Human-computer interaction