Multichannel data acquisition system for the survey of intercostal muscle activity

A 32 channel data acquisition system for the survey of intercostal muscle activity in the cat has been developed. Electromyographic signals, picked up by electrodes implanted in the intercostal muscles, are conditioned to be digitised and recorded on a magnetic tape through an on-line digital computer. In this signal conditioning, significant importance is given to motor unit selection and weighing, according to their size and distance from the electrode pick up point. A low pass-filter, with a response time course similar to the one observed in the twitch of the intercostal muscles of the cat, is also used. Since data obtained in the process is time locked, synchronised multichannel time domain analysis can be achieved.