Abstract: A transcutaneous nerve stimulation device is provided using a common controller for both output pulse production and treatment parameter display. The common controller, which preferentially takes the form of a programmed microprocessor, is connected by signal lines to both the pulse output circuitry and the display, which are controlled by time-sharing the signal lines. The controller is responsive to operator entered input signals for the calculation of output pulse characteristics and display parameters. During a majority of treatment time, the controller is providing signals on the signal lines for control of the display. The display signals are interrupted during timed intervals when output signals are produced.

Abstract: A sentinel system is provided for a transcutaneous nerve stimulation device in which a sentinel pulse of known characteristics is produced at the device output prior to the production of a stimulation pulse. The output response is measured during the time of sentinel pulse production, and a sentinel warning signal is produced if an undesired output response is measured to alert the user to a potentially hazardous condition.