Development of multichannel array transducer of displacement mechanical-myogram.

The myoelectric signal (EMG) recorded on the skin surface is a time-related and spatial aggregate of the action potentials of motor units of skeletal muscle, and it indicates the input information for muscle contraction. The mechano-myographic signal (MMG) is a vibration of skin/muscle surface caused by muscle contraction and it directly reflects the activity of muscle contraction. The two-dimensional generation mechanism of MMG is still n ot clarified in detail. In this study, the displacement MMGs were recorded at 25 measuring points using 5 × 5 displacement MMG array transducer within 50× 50 mm, while the motor point of the biceps brachii was electro-stimulated. The spatial propagation map of twitch waveform of displacement MMG was drawn.