Detection of Neuromuscular Activity Using New Non-Invasive and Flexible Multimaterial Fiber Dry-Electrodes

A new non-invasive and flexible sensor was fabricated to monitor the muscular activity of upper body muscles. It consists of a dry electrode made of multimaterial metalpolymer-glass hollow-core fiber electrodes connected to a custom made signal acquisition platform. This fiber electrode only adds a negligible contribution to the recording system's internal noise (7.626 μV peak-to-peak and 1.234 μV RMS; recording system noise: 6.901 μV peak-to-peak and 1.205 μV RMS). Surface electromyograms (sEMGs) of the biceps bracci and trapezius muscles were recorded during maximal voluntary contractions using the new sensor and compared to that obtained with medical grade commercial sensors. Frequency content and time domain analysis show that the new flexible sensor performs similarly to commercial devices in terms of sEMG signal amplitude discrimination and frequency shift evaluation during the development of muscle fatigue. The advantage of the new sensor is the high flexibility of the fibers allowing their easy integration into stretchable garments without compromising the user's comfort. This will lead to the development of a new generation of smart textile with large application for telemedicine and assistive devices.