A wearable pneumatic-piezoelectric system for quantitative assessment of skeletomuscular biomechanics

Mechanical assessments of skeletal muscles have profound relevance in the clinical diagnosis, management, and treatment of neuromuscular diseases. Current clinical measures of muscular biomechanics involve either non-instrumental methods that are subjective and qualitative or bulky instruments with limited accessibility. Here, we develop a wearable device that integrates a pneumatic actuator and a piezoelectric sensor for in vivo measurements of muscular elasticity, where machine learning models are adopted to evaluate the severity of neuromuscular diseases. The wearable conforms to the human body and couples mechano-electrically with the underlying tissues, thereby correlating their elastic moduli with the sensor's voltage output. Clinical validation was performed on both normative and spastic biceps muscle. Quasi-static tests measure the effective moduli of the muscles, while dynamic tests continuously monitor the modulus change in biceps muscle during rapid joint stretches. This work establishes a new paradigm for remote diagnosis and tele-rehabilitation of muscle-related pathophysiological conditions.