16 CHANNEL BRAIN TISSUE STIMULATOR

Computer Engineering electronics Engineering Civil Engineering

The pathways of brain circuitry can be studied by delivering current impulses to brain tissue and observing the tissue response. The goal of this project is to develop a current source to be used for in vitro stimulation of rodent neural tissue. The current source must deliver independently controlled currents to 16 separate electrodes on a 16 microelectrode array. In addition, the currents must be controllable via TTL computer logic and have a short response time to the initial signal. The design described in this report uses a transformer to supply a large isolated voltage to 16 circuits which will convert the voltage to an appropriate current. The current on each channel will be controlled by a potentiometer which varies the magnitude of the impulse received from a TTL computer signal. When the computer program supplies an impulse, a corresponding square wave current pulse will be applied to the tissue. loading..