Design of a Switch Controller for Paralytic Patients Using EEG

This report describes the EEG based switching system that uses voluntary eye blinks extracted from EEG signals for activation purpose. Here 2 surface electrodes are placed over the frontal region of the skull and the 3rd one near the auricular region for reference, for the purpose of extraction of EEG wave from the patient. It was found that EEG signal obtained during voluntary eye blink, produces clearer signals with larger amplitude and with a frequency differing from that of the normal EEG. An ARM processor is programmed for efficient extraction of eye blinks. Our system is operated in 2 modes -- Voice mode which is used by the patient to express what they want and control mode which helps the patient in switching ON or OFF a particular device. These modes helps in reducing the paralytic subject´s burden to a great extent. In the first mode, the extracted pulse is transmitted wirelessly to the relay circuit using Zig bee technology. A relay circuit is activated to turn ON the desired device. Whereas in the second mode, the extracted blink will be used to select and lay the necessary voice file for the paralytic patient (these voice files are some pre-defined recordings of a person´s basic needs).