Miniature voltage sensitive dye imaging system for in vivo experiments

Currently, there are no widely used methods of optically recording rapid electrical events over a wide cortical area in freely moving animals. This paper presents an image sensor for recording electrical activity of large regions (4-9 mm
²
) of the nervous tissue at high speeds (> 500 Hz) using voltage sensitive dye imaging (VSDI) in freely moving animals. Each 75 mum x 75 mum pixel consists of a photodiode of 74 mum x 34 mum and a storage capacitor of 788 fF. The image sensor has a signal-to-noise ratio of 76 dB.