An implantable mixed analog/digital neural stimulator circuit

This paper describes a chip for a multichannel neural stimulator for functional electrical stimulation. The chip performs all the signal processing required in an implanted neural stimulator. The power and signal transmission to the stimulator is carried out via an inductive link. From the signals transmitted to the stimulator, the chip is able to generate charge-balanced current pulses with a controllable length and amplitude for stimulation of nerve fibres. The chip has 4 output channels so that it can be employed in a cuff electrode with multiple connections to a nerve. The purpose of the functional electrical stimulation is to restore various bodily functions (e.g. motor functions) in patients who have lost them due to injury or disease.