완전삽입형 인공망막 구현을 위한 인공망막모듈 개발

• Published in: Journal of biomedical engineering research Vol. 31; no. 4; pp. 292 - 301
• Main Authors: 이강욱, 카이호 요시유키, 후쿠시마 타카후미, 타나까 테츠, 고야나기 미쯔마사, Lee, Kang-Wook, Kaiho, Yoshiyuki, Fukushima, Takafumi, Tanaka, Tetsu, Koyanagi, Mitsumasa
• Format: Journal Article
• Language: Korean
• Published: 대한의용생체공학회 01.08.2010
• Subjects: 의공학; rerinal prosthesis module; 3D stacked retinal chip; stimulus electrode; fully implantable retinal prosthesis
• ISSN: 1229-0807; 2288-9396

To restore visual sensation of blind patients, we have proposed a fully implantable retinal prosthesis comprising an three dimensionally (3D) stacked retinal chip for transforming optical signal to electrical signal, a flexible cable with stimulus electrode array for stimulating retina cells, and coupling coils for power transmission. The 3D stacked retinal chip is consisted of several LSI chips such as photodetector, signal processing circuit, and stimulus current generator. They are vertically stacked and electrically connected using 3D integration technology. Our retinal prosthesis has a small size and lightweight with high resolution, therefore it could increase the patients` quality of life (QOL). For realizing the fully implantable retinal prosthesis, we developed a retinal prosthesis module comprising a retinal prosthesis chip and a flexible cable with stimulus electrode array for generating optimal stimulus current. In this study, we used a 2D retinal chip as a prototype retinal prosthesis chip. We fabricated the polymide-based flexible cable of $20{\mu}m$ thickness where 16 channels Pt stimulus electrode array was formed in the cable. Pt electrode has an impedance of $9.9k{\Omega}$ at 400Hz frequency. The retinal prosthesis chip was mounted on the flexible cable by an epoxy and electrically connected by Au wire. The retinal prosthesis chip was cappted by a silicone to pretect from corrosive environments in an eyeball. Then, the fabricated retinal prosthesis module was implanted into an eyeball of a rabbit. We successfully recorded electrically evoked potential (EEP) elicited from the rabbit brain by the current stimulation supplied from the implanted retinal prosthesis module. EEP amplitude was increased linearly with illumination intensity and irradiation time of incident light. The retinal prosthesis chip was well functioned after implanting into the eyeball of the rabbit.