MuscLab: A Flexible and Elastic e-Textile Band for Monitoring Muscle Contraction

Abstract

Mecanomyographic (MMG) and force myography (FMG) sensors emerged as an alternative to electromyography (EMG) for monitoring muscle contraction without requiring the direct contact of the sensor with the user’s skin. Nonetheless, most of the available sensors 1) require as many sensors as there are muscles to monitor, resulting in a time-consuming preparation for practical use and 2) present a nonelastic nature, entailing a customized design to the user’s segment anthropometries. Thereby, we developed the MuscLab system, which uses e-textile (piezoresistive textile) sensors sewn onto a flexible and elastic textile band. It simultaneously monitors and discriminates muscle contractions across different muscle groups in individuals with a shank perimeter ranging from 33.5 to 48.7 cm. From a benchmark analysis involving ten non-disabled individuals, the MuscLab was able to 1) detect muscle contractions at different motion cadences, with an average delay of 135.8 ± 78.0 ms and strong spearman correlation (0.78 ± 0.08) regarding EMG signals of tibialis anterior (TA) and gastrocnemius lateralis (GALs) and 2) distinguish different levels of muscle contraction performed at different ankle joint angles (the average coefficient of determination of 0.92 ± 0.10 and 0.89 ± 0.16 for ankle dorsiflexion and plantar flexion movements, respectively). This research advances with new insights regarding the use of e-textiles in an elastic band for monitoring the multimuscle contraction of users with different anthropometries.