A 16-channel CMOS neural stimulating array

Electrical stimulation in the central nervous system is a valuable technique for studying information-processing techniques in neural circuits and is a key element in the development of neural prostheses for deafness and other disorders. In the past, such stimulation has typically been implemented using wide electrodes to inject small currents into the tissue to activate nearby neurons. However, the physical characteristics of these electrodes are difficult to control, and they tend to splay out in tissue, making their relative positions unknown when used in arrays. The probe presented overcomes these difficulties, providing 16 independent stimulating sites, yet displacing no more tissue than would a single wire electrode. Highly selective stimulus patterns can be generated electronically by superimposing current from several spatially distributed sites. The probe operates at low power levels and requires only five external leads.<>