Research And Implementation Of Key Technologies In Functional Electrical Stimulation Chip

Functional Electrical Stimulation (FES) is widely used in therestoration of muscle motor function for paralyzed patients as a neuralinterface technology nowadays. Miniature, portable, low powerconsumption, implantable and mild injury are the development trends ofFES systems. Stimulator is the key module of a FES system, so it ismeaningful to design a universal and configurable stimulator for thedevelopment and application of FES systems.The design specifications of the stimulator chip are proposed on thebasis of its possible application fields, and the structure and the format ofdata transmission are designed by researching the existing FES systems.Then the electrical and process characteristics and the usage of highvoltage devices are introduced, with which the current output stage of thechip is designed. Finally the simulation results of each module and thelayout of the whole chip are presented.The chip is fabricated in an X-FAB0.35μm process. The digitalcontroller gets data packets through the SPI interface of the chip, anddistributes data to each channel through parallel bus to drive the outputstage to generate biphasic stimulation currents. This chip is8-channel, andwill be upgraded to64channels in the future. With a supply voltage of upto90V, a maximum current of4mA can be generated for each channel.