An Ultra-light and Flexible sEMG Active Probe for Patch-like Muscle Activity Monitoring

Surface ElectroMyoGraphy (sEMG) constitutes a valid tool for monitoring muscle activity in sports, rehabilitation, control of Human-Machine Interfaces (HMIs), and telemonitoring. To extend its applicability beyond clinical settings, the wearability of acquisition systems is a key factor, allowing for reduced discomfort during use, acquiring signals without hindering movement, and reducing the risk of detachment during the acquisition. This paper proposes a flexible, lightweight (0.81 g), and extremely compact active probe, measuring 30 mm x 10 mm x 3 mm, produced using rigid-flex PCB technology. The experimental tests, conducted on five subjects, each one performing six dynamic movements, show that the developed probe is capable of acquiring good quality sEMG signals, with a median Signal-to-Noise Ratio (SNR) of 10.9 dB. Additionally, the minimal power consumption of the active probe, amounting only to 0.732 mW, makes the probe suitable for battery-powered applications, e.g., activities of daily living long-term recordings.