Mind Control of Systems Designing a system to measure brain waves in order to obtain commands to control the direction of a remote-control car By Gary Obenski & Jim Bradbury

Primary Goals Determine an efficient way to obtain brain wave signals from human subject Determine a way to change different wave patterns to commands such as ‘left’ and ‘right’

Electroencephalography Science of recoding electric currents produced by human brain Discovered by Hans Berger in late 1920’s

Brain waves Arise from cerebral cortex Byproduct of normal brain function Millions of pyramidal cells produce small currents as the nerve impulses change

Four types of waves AlphaBeta Theta Delta

Similar experiments Mind control by rats US Air Force flight simulator

Biofeedback Alternative method to try to interpret brain wave signals Trains individual to learn how to produce specific frequencies

Where to go now… Acquire the means to harness EEG waves (Integration of Amplifier and Filter) Interpret signal as “1’s” and “0’s” Condition subject to consistently produce desired signal Interface EEG waveform to computer software Change the world!!!

Initial Design Differential amplifier  Minimum gain of 10,000  Bandwidth of 0.5 Hz to 50 Hz  Low noise

Options Buy amplifier  Easier  Cost consideration Design amplifier  More difficult  More flexible

Amplifiers Brainmaster circuit Modified instrumentation amplifier

Brainmaster circuit diagram

Brainmaster circuit specs Gain : 20,000 Bandwidth : 1.7 – 34 Hz Input Impedance : 10 Mohms CMRR : 100 dB

Instrumentation amplifier circuit diagram

Instrumentation amp frequency response Gain : 20,000 Bandwidth : 0.2 Hz - high value (depends on gain-bandwidth product of op-amp)

Test Compare each circuit Modify if needed Decide which one to use  Flexibility  Cost  Performance

Modified Circuit Diagram

Specs Gain : 20,000 V/V 86 dB Bandwidth : > 1 kHz CMRR : 102 dB

Output Signal

Frequency Response

BrainMaster Model: Simulation Schematic

Simulation Results

Output Waveform of First Stage

Output Waveform Second Stage

Frequency Response of BrainMaster Amplifier

Problems with BrainMaster and Solution Voltage Divider of would not register any AC Signal Unable to Couple the Two Stages SOLUTION: Always have an alternative design it case one goes wrong.