Eeg Signal Acquisition And Processing System Design

Electroencephalogram (EEG) signal is a typical signal of bioelectricity. When nerve cells of a brain transmit information, it is a general reflection of electrical activities in the cortical layer and on the scalp, which contains much physiological and pathological information. We can learn the relationship between the electrical activities of nerve cells and the physiological and pathological states of people, and this relationship has great significance in the province of the clinical medicine and the cognitive science.EEG is so weak. The background noise of EEG is very strong and the characteristic of non-stationary random bioelectricity of EEG is outstanding. The valuable data of EEG only can be got from statistical result from large numbers of experimental data. The traditional EEG analyzers are expensive, and usually worked inaccurate, which is not convenient to use. On the foundation of basic EEG knowledge, this dissertation originally researched acquisition and processing of EEG. The main job including:1. Study the generation, assortment, lead, placement of electrode detailedly.2. An adjustable amplifier of gain and frequency in EEG acquisition system was designed according to the features of EEG.. A band filter was designed forαwave specifically in addition. Filters comprise EEG low pass filter, EEG High pass filter, EEG band filter, EEG band elimination filter.3. Adopted TMS320LC549 DSP as processor, using HPI as interface with computer to implement communication, saving of data, EEG acquisition circuit was designed by A/D, memory expandability and communication system to collect data to computer system.4. ICA (Independent Component Analysis) algorithm was applied to removing artifacts by efficiency of studies in the theory of removing artifacts, characteristic analysis and feature extraction.