Stimulator Design of Retinal Prosthesis

Jun OHTA  Toshihiko NODA  Kenzo SHODO  Yasuo TERASAWA  Makito HARUTA  Kiyotaka SASAGAWA  Takashi TOKUDA  

IEICE TRANSACTIONS on Electronics   Vol.E100-C   No.6   pp.523-528
Publication Date: 2017/06/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E100.C.523
Type of Manuscript: INVITED PAPER (Special Section on Analog Circuits and Their Application Technologies)
retinal prosthesis,  neuro-stimulation,  implantable devices,  electrical stimulation,  AC power delivery,  

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This study focuses on the design of electrical stimulator for retinal prosthesis. The stimulator must be designed such that the occurrence of electrolysis or any irreversible process in the electrodes and flexible lead is prevented in order to achieve safe stimulation over long periods using the large number of electrodes. Some types of biphasic current pulse circuits, charge balance circuits, and AC power delivery circuits were developed to address this issue. Electronic circuitry must be introduced in the stimulator to achieve the large number of electrodes required to obtain high quality of vision. The concept of a smart electrode, in which a microchip is embedded inside an electrode, is presented for future retinal prostheses with over 1000 electrodes.