Design of Prototype EEG Signal Card

Abstract

In this study, it is aimed to perform an portable EEG signal acquisition card. A portable biomedical signal recorder is significant for the detection of symptoms which are encephalitis, brain neoplasms, epilepsy etc. By using an EEG recorder, investigators and clinicians have more opportunity to analyze symptoms from the long-duration recorded signals. This project is further divided into three parts which are the acquisition, gain and filtering. EEG signals are acquired from the patient by means of probes. And these signals are transmitted to amplifier. For an EEG amplifier, it consists of an instrumentation amplifier (IA) followed by a low pass filter, high pass filter, and a notch filter. Firstly, EEG signals are amplified by use of AD623 which is an instrumentation amplifier (IA). After, amplified EEG signals pass into low pass filter and the signal will be filtered to eliminate signal noise. Then the signals entered high pass filter and notch filter which have been used in the past for applications like elimination of 50 Hz hum components, respectively. Finally, output signal will be detected by using digital oscilloscope for signal analysis.

Key words: EEG, biomedical, signal processing.