A miniaturized implantable spinal cord microstimulator for treating intractable chronic pain

An advanced fully programmable spinal cord stimulation system is described. The system delivers controlled electrical pulses to an electrode array placed on selected nerve fibers along the spinal cord. It is composed of three main parts: two different external control units and a surgically implanted module. The first external part consists of a computer system with completely graphical software and appropriate hardware interface, intended for the physician to program the internal part. The second external unit is a very small simple switch that will be used by the patient to start and stop stimulation at his convenience. A RF carrier provides both data and power for the implant through a closely coupled inductive link. The internal part consists of a microstimulator built around a full custom mixed-signal microprocessor generating different programmable current waveforms. This chip is mounted together with different satellite components on a hermetically housed hybrid circuit