Title :
Improvement of a pulse frequency modulation based photosensor for retinal prosthesis
Author :
Ohta, Jun ; Furumiya, Tetsuo ; Ng, David C. ; Uehara, Akihiro ; Kagawa, Keiichiro ; Tokuda, Takashi ; Nunoshita, Masahiro
Author_Institution :
Nara Inst. of Sci. & Technol., Japan
Abstract :
This paper describes improvements in output waveform of pulse frequency modulation (PFM) photosensor to be effectively adapted for retinal prosthesis. A 32×32-pixel PFM photosensor array chip is fabricated using 0.6 μm CMOS technology and demonstrated the improved functions. Also the output pulse pattern is displayed with 32×32-LED array to visualize the pulse output waveform. The next version of a PFM vision chip is designing for in vivo experiment, in which in-pixel image processing functions in pulse domain are employed.
Keywords :
CMOS image sensors; biomedical electronics; eye; prosthetics; pulse frequency modulation; 0.6 micron; 32×32-LED array; CMOS image sensors; CMOS technology; PFM photosensor array chip; PFM vision chip; in pulse domain; in-pixel image processing function; output pulse pattern; pulse frequency modulation photosensor; pulse output waveform; retinal prosthesis; CMOS technology; Circuit testing; Dynamic range; Frequency modulation; In vivo; Photodiodes; Prosthetics; Pulse modulation; Retina; Visualization;
Conference_Titel :
Sensors, 2003. Proceedings of IEEE
Print_ISBN :
0-7803-8133-5
DOI :
10.1109/ICSENS.2003.1278922
