Measurement of a Motor Unit activity from matrix surface Electromyogram

The aim of this study is to estimate single motor unit action potential (sMUAP) firing time and muscle fiber conduction velocity (MFCV) by surface electromyogram (sEMG). We made the matrix surface electrode of 8×8 that got 56ch sEMG signals. The 56ch sEMG signals were recorded from the biceps brachii muscles during isometric contraction at 20% maximal voluntary contraction. We used Independent Component Analysis (ICA) and the template matching for the identification of sMUAP. By using the results of identification, we estimated sMUAP firing time. As sEMG is interference of many sMUAP, ICA is useful for making it easy to detect sMUAP train. Using the estimated sMUAP firing time, we calculated the averaged MUAP waveforms at each electrode. Finally we estimated MFCV by using averaged sMUAP waveforms.