Programmable Chip EEG

The Programmable Chip EEG is a dual channel electroencephalograph that could be a brain-computer interface.

The Programmable Chip EEG is programmable because it uses Digitally Programmable Potentiometers. They are used to set the Gain, frequency range, and can calibrate multiple analog boards for different EEG tests.

Parts used in the PCEEG:

• The digital POT made by analog devices (AD5204) has 255 positions can be adjusted by the microcomputer that can receive commands from the computer. This is a great way for analog circuitry to have digital control.

• The differential analog signals are amplified by the LT1114 opamp.

• Then the signal is amplified and conditioned by high pass and low pass filters.

The common mode signal is inverted summed and sent back to the body to decrese common mode signal thsi is done by the driver right leg circuit.

Band reject filters may be added soon in the future.

Then the analog signals are simultaniously digitized and the digital values can be clocked to the digital board.