Development of Implantable Neuro-Stimulator Used for Brain and Nerve Stimulation

Abstract

The aim of this paper is to develop a programmable and implantable neuro-stimulator for animal research and clinical application. The neuro-stimulator includes implantable pulse generator, extension (if necessary) and lead implanted in the body, and controller, PDA and magnet used outside the body for telemetry/programming. It provides electrical pulse stimulation to the target nerve or brain nucleus, with adjustable pulse parameters of pulse width, frequency, amplitude, on time and off time. The ultra-low power consumption circuit based micro-processor was developed, and welded with primary lithium battery, then were sealed by titanium case and feedthroughs hermetically using laser welding. The implantable pulse generator has the weight of about 34 g, the size less than 47*52*11 mm, and two kinds of circuit can be installed in it, i.e. current pulse control for nerve stimulation and voltage pulse control for brain stimulation. The pulse parameters of amplitude, pulse width, frequency and electrode configuration can be programmed by controller and PDA, e.g. pulse amplitude is 0–10V in 0.05V or 0.1V steps for voltage pulse control, 0–3.5mA in 0.1mA steps for current voltage pulse control. The neuro-stimulator has been validated the safety and function during long-term implantation by animal experiments of vagus nerve stimulation (VNS) using 20 rabbits and deep brain stimulation (DBS) using 1 rabbit, and DBS experiments for PD treatment using rhesus monkey is in process. The developed neuro-stimulator can be used in clinical application of DBS, VNS and other brain/nerve stimulation, and also an instrument platform for animal experiment research of implantable neuro-stimulation to study therapy mechanism and optimized stimulation parameters.