Title :
Pixel design of pulsed CMOS image sensor for retinal prosthesis with digital photosensitivity control
Author :
Kagawa, K. ; Isakari, K. ; Furumiya, T. ; Uehara, A. ; Tokuda, T. ; Ohta, Jun ; Nunoshita, M.
Author_Institution :
Nara Inst. of Sci. & Technol., Japan
fDate :
3/6/2003 12:00:00 AM
Abstract :
A newly designed pulse frequency modulation photosensor for use in retinal prosthesis is proposed and demonstrated. The pixel converts the intensity of incident light into biphasic current pulses at frequencies suitable for the electrical stimulation of retinal neurons. Experimental results showed that the device was sensitive over a dynamic range of input light of about 120 dB, and that photosensitivity could be varied from 0 dB to around -40 dB.
Keywords :
CMOS image sensors; biomedical electronics; eye; prosthetics; pulse frequency modulation; digital photosensitivity control; dynamic range; electrical stimulation; pixel design; pulse frequency modulation photosensor; pulsed CMOS image sensor; retinal neurons; retinal prosthesis;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:20030325