A programmable signal analysis device for detecting and counting neurological and muscular events in living tissue that incorporates one or more signal threshold levels to identify an event, a counter to count events, and a timer to determine event frequency as events per unit time. The threshold levels and counter/timer operating modes/parameters are digitally programmable to identify and count events, i.e., electrical signals having defined parameters. Such a circuit is of particular use in a microstimulator/sensor which is capable of being injected into living tissue at the site of interest. The microstimulator/sensor is used to stimulate a neural pathway or muscle and/or to block a neural pathway to alleviate pain or block stimulation of a muscle.