Title :
Pulse frequency modulation based CMOS image sensor for subretinal stimulation
Author :
Ng, David C. ; Furumiya, Tetsuo ; Yasuoka, Koutaro ; Uehara, Akihiro ; Kagawa, Keiichiro ; Tokuda, Takashi ; Nunoshita, Masahiro ; Ohta, Jun
Author_Institution :
Nara Inst. of Sci. & Technol.
fDate :
6/1/2006 12:00:00 AM
Abstract :
We have developed a CMOS image sensor based on pulse frequency modulation for subretinal implantation. The sensor chip forms part of the proposed intraocular retinal prosthesis system where data and power transmission are provided wirelessly from an extraocular unit. Image sensing and electrical stimulus are integrated onto the same chip. Image of sufficient resolution has been demonstrated using 16times16 pixels. Biphasic current stimulus pulses at above threshold levels of the human retina (500 muA) at varying frame rates (4 Hz to 8 kHz) have been achieved. The implant chip was fabricated using standard CMOS technology
Keywords :
CMOS image sensors; eye; neuromuscular stimulation; prosthetics; pulse frequency modulation; 4 to 8000 Hz; 500 muA; CMOS image sensor; biphasic current stimulus pulses; data transmission; electrical stimulus; extraocular unit; human retina; image sensing; intraocular retinal prosthesis system; power transmission; pulse frequency modulation; subretinal stimulation; CMOS image sensors; CMOS technology; Frequency modulation; Image resolution; Pixel; Power transmission; Prosthetics; Pulse modulation; Retina; Sensor systems; CMOS image sensor; pulse-frequency modulation (PFM); retinal prosthesis; subretinal implant;
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
DOI :
10.1109/TCSII.2006.875334
