Mechanomyogram measurement by lead zirconate titanate-based acoustic sensor

In this research, we focused on the mechanomyogram (MMG) for evaluating muscle activity. MMG signals were measured using a lead zirconate titanate (PZT)-based acoustic sensor. In previous research on MMG measurement, low-frequency MMG signals ranging from 10 to 100 Hz were mainly measured. On the other hand, where, MMG signals higher than 100 Hz, which is considered to be related to the resonance of muscle fibers, were focused on. To measure high-frequency components of MMG signals, we used a PZT-based acoustic sensor and measured the MMG of the biceps brachii muscle of four subjects. As a result, it was confirmed that all the subjects showed frequency components of 10 Hz to 10 kHz in the MMG. In particular, we confirmed that as the force exerted by the muscles increases, MMG signals of 100 Hz to 10 kHz become larger.