A programmable-gain VLSI circuit and system for sensing and stimulating action potentials of neuronal networks

An analog/digital VLSI chip and a 64-channel system using four of the chips for sensing and stimulating signals from live neuronal networks are described. Each chip has 16 analog channels, each having an instrumentation amplifier with a programmable gain of either 27, 50, or 60. In the system sense mode the action potentials from the network can be monitored and amplified on any or all selected channels. In the system stimulation mode up to four external stimulation signals can be routed to the network through any or all of the 16 channels. A 4×16 cross-point transmission-gate array connects the stimulation signals to the selected channels. The network response to the stimulation signals can be monitored at the output of selectable channels