Measurement of mechanomyogram

We have proposed an approach for measuring mechanomyogram (MMG) by taking advantage of the acoustic impedance matching between liquid and human skin. Using liquid, we could convey the pressure signal of MMG to a piezo-resistive cantilever efficiently. In experiments, the sensor was placed on the skin surface over biceps brachii (a large muscle that is located in the upperarm). The MMG signal, of which the frequency was in range of 10-15 Hz, was able to be detected using silicone oil as the propagating medium. On the other hand, there was no response in the case of using air as the medium. Experimental results also indicated that the proposed sensor was able to detect the vascular oscillations.