Multichannel multipurpose implantable nerve stimulators

On the basis of experiences gained in clinical applications of functional electrostimulation of nerves with implantable stimulation units, 20-channel implants fabricated in thick-film technology and using gate array circuits were developed. Extracorporal power supply and adjustment of stimulation parameters are accomplished by using a versatile microprocessor-based device that can be attached to the belt of the patient. The device (12×4×6 cm) can program and supply two implants. The supply unit consists of a CMOS microcomputer (80C51) with 32-kb EPROM (electrically programmable read-only memory), a 32-kB RAM (random access memory), an eight-channel ADC (analog-to-digital converter), a watchdog, a real-time clock, an acoustic signal, an eight-character display, and an RS232 link to communicate with a PC either directly or through a modem