抄録
A man-machine interactive mini-computer system is described for the analysis of EMG and twitch waveforms of motor units in man during voluntary isometric contraction.
EMG picked up with bipolar needle electrode and recorded on an FM tape recorder is A/D converted and stored in a magnetic disk. The sampled data are divided into time segments and sequentially displayed on a graphic display. EMG spikes of up to five motor units per channel are visually discriminated by the operator and the timing of each spike is selected with a light pen. A maximum of 4, 000 firing points of motor units per channel could be selected from the record of 100 sec, and stored on magnetic tape for further analyais. Four EMG channels are processed separately and the synchronization between channels is assured by the marker pulse recorded on the FM tape recorder.
The total force of the muscle is then A/D converted and averaged with respect to the firing points of one motor unit to yield the twitch waveform of that motor unit. In the present system, twitch waveforms of twenty motor units could be obtained from the records measured at one time. This system allows the electromyographical characteristics of motor units and the mechanical ones to be correlated with each other. Therefore, it will prove valuable as a tool for investigating the mechanism involved in the voluntary control of muscle tension in man.
