CMOS prototype for retinal prosthesis applications with analog processing

Autor: G. Castillo-Cabrera, J.A. Moreno-Cadenas, L.M. Flores-Nava, J. Garcia-Lamont, Y. Matsumoto-Kuwabara, M. A. Reyes-Barranca
Rok vydání: 2014
Předmět:
Zdroj: International Journal of Electronics. 101:1621-1646
ISSN: 1362-3060
0020-7217
DOI: 10.1080/00207217.2014.888776
Popis: A core architecture for analog processing, which emulates a retina’s receptive field, is presented in this work. A model was partially implemented and built on CMOS standard technology through MOSIS. It considers that the receptive field is the basic unit for image processing in the visual system. That is why the design is concerned on a partial solution of receptive field properties in order to be adapted in the future as an aid to people with retinal diseases. A receptive field is represented by an array of 3×3 pixels. Each pixel carries out a process based on four main operations. This means that image processing is developed at pixel level. Operations involved are: (1) photo-transduction by photocurrent integration, (2) signal averaging from eight neighbouring pixels executed by a neu-NMOS (ν-NMOS) neuron, (3) signal average gradient between central pixel and the average value from the eight neighbouring pixels (this gradient is performed by a comparator) and finally (4) a pulse generator. Each one of...
Databáze: OpenAIRE