A fully implantable wireless system for sciatic nerve recording and stimulation

Abstract

This paper presents a novel implantable system that could simultaneously perform recoding and stimulation of the nerve. All of acquired neural signal, communication data and power are transferred wirelessly. Unlike conventional studies which perform recording and stimulation separately via each device [1], this system was integrated recording and stimulation circuit together in this study. Data communication was performed through medical implant communication service (MICS) band. With the assistance of this MICS band, distance between implantable system and host computer could be expanded than the previous system which is using load shift keying (LSK) technique [2]. To supply power for implantable system, rechargeable battery pack was used. When charging is needed, the power was transferred with an efficiency of around 50% at 120kHz via inductive radio frequency(RF) link. Devised implantable system in this study was able to acquire 2 sites of neural signal and stimulate 2 sites. For raw neural signal acquisition, the user not only could able to set gain of the amplifier of analog board but also adjust the blanking time to gather the neural signal selectively. Also, stimulation wave could be generated with the user’s intention as soon as the command is delivered from host computer to implant system wirelessly. To evaluate the proposed system, in vivo experiments were performed using a New-Zealand white rabbit animal model to record and stimulate the neural signals from the sciatic nerve.