Development of low cost electrical nerve stimulator based on a simple circuit topology

This paper presents detailed design of a simple low cost circuit topology for electrical nerve stimulator. To synthesize the required electrical current signal from a voltage source, a transconductance amplifier has been introduced. In order to maintain a good quality of current signal envelope with no rising or falling edge harmful distortion as well as independent of load resistance, a low pass filter as well as a Type-II compensator have been incorporated. Signal generation of desired pulse-width, frequency and magnitude are adjusted digitally through micro-controller with a vector keypad for user interface. Details analysis of circuit-configuration and experimental results are presented to validate the proposed circuit configuration as a stimulator.