Acquisition and Processing of Dual Channel EEG Signals to Extract and Analyze Alpha Band

Abstract

Electroencephalography (EEG) is used to determine the overall electrical activity of the brain and can be very revealing in the study of various physiological and pathological states. The time and frequency variations, characteristic of EEG signals, can be associated with different motor, sensory and psychological behaviors. The expensive equipment and cumbersome nature generally associated with acquiring EEG signals for medical diagnosis has been a hindrance to its use as a product in consumer settings. In this study, a simple dual channel EEG acquisition circuit is developed using analog components to acquire frequencies associated with the alpha band. A microcontroller is then used for post- acquisition signal processing in the frequency domain. The setup is demonstrated by classifying between the open and closed state of the subjects’ eyes. The low-cost and lightweight nature of the device along with low computation power required for post- acquisition processing, makes it easier to be deployed in real- time applications.