A Chip for an Implantable Neural Stimulator

TLDR: In this paper, the authors describe a chip for a multichannel neural stimulator for functional electrical stimulation (FES), which is able to generate charge-balanced current pulses with a controllable length up to 256 μs and an amplitude up to 2 mA.

Abstract: This paper describes a chip for a multichannel neural stimulator for functional electrical stimulation (FES). The purpose of FES is to restore muscular control in disabled patients. The chip performs all the signal processing required in an implanted neural stimulator. The power and digital data transmission to the stimulator passes through a 5 MHz inductive link. From the signals transmitted to the stimulator, the chip is able to generate charge-balanced current pulses with a controllable length up to 256 μs and an amplitude up to 2 mA, for stimulation of nerve fibers. The quiescent current consumption of the chip is approx. 650 μA at supply voltages of 6–12 V, and its size is 3.9×3.5 mm^2. It has 4 output channels for use in a multipolar cuff electrode.