Suppression of stimulation artifacts from myoelectric-evoked potential recordings

A system that allows detection of single and double differential surface myoelectric signals during electrical stimulation of either the nerve or the muscle motor point, using surface electrodes, is described. The input referred stimulation artifact is limited to less than 24 mu V _pp by a switching constant current/constant voltage output stage, slew rate limiting, and time windowing of the detected signal. The system is suitable for muscle crosstalk and for muscle fatigue investigation during functional electrical stimulation, in addition to measuring muscle or nerve conduction velocity.