Pneumatic Microneedle-Based High-Density sEMG Sleeve for Stable and Comfortable Skin Contact During Dynamic Motion

Abstract

Skin impedance should be minimized to obtain reliable and precise surface electromyography (sEMG) signals. High skin impedance decreases sensitivity to muscular activation and makes sEMG signals vulnerable to external noise. Microneedle-based electrodes have been proposed to achieve low skin impedance and high spatial resolution. However, unstable skin contact can occur during dynamic motion due to the electrodes small contact area, and the signal is easily influenced by motion artifacts. In this study, a pneumatic microneedle-based high-density sEMG sleeve is proposed that guarantees stable sEMG signal measurement by pressing the electrodes to the skin. Pneumatic air control, sEMG signal processing, and wireless signal transmission are processed in a single processor. The proposed interface automatically controls the air volume according to sEMG signal quality and is comfortable for users. The usability of the proposed interface was compared to conventional Velcro armbands by examining acquired sEMG signals. The results indicated that the proposed pneumatic sleeve guarantees reliable sEMG signal measurement during dynamic motion. Additionally, optimal pneumatic pressure and needle length were investigated.