Quantitative Muscle Fatigue Estimation with High SNR Flexible Skin Electrode

In recent years, surface electromyography (sEMG) has been commonly used to diagnose neuromuscular abnormalities. Since sEMG measures electrical signals from various tangled muscle nerves, a high signal-to-noise ratio (SNR) is required to estimate the condition accurately. Previously, Ag/AgCl electrodes were widely used for sEMG measurements, but noble metals are more advantageous for long-term and continuous measurement. In this study, we improved the SNR of bioelectrical signals by increasing the surface area of a flexible skin-electrode made of noble metal. The electrode surface area was increased by 1.38 times with electroplating, and the SNR of sEMG was improved by 1.63 times. Utilizing the sEMG signals with high SNR, we propose a new muscle fatigue estimation algorithm for monitoring the muscle condition in real-time.