Voltage sensitive dye imaging system for awake and freely moving animals

Abstract

A 32 times 32 pixel image sensor in bulk CMOS process for use in a custom voltage sensitive dye imaging system is presented. The system is to be mounted on awake and freely moving animals in order to measure brain activity. The image sensor is capable of on-chip temporal-differencing using a storage capacitor on-chip. Temporal-differencing is used to reduce the stress on the overall readout circuitry in order to meet size and power constraints of such a system. Each 75 mum times 75 mum pixel consists of a photodiode of 74 mum times 34 mum and a storage capacitor of 788 fF. The image sensor has a signal-to-noise ratio of 76 dB.