8 Channels Portable Eeg Acquisition System Design

EEG as an expression of the brain electrical activity, has received researchers’ extensive attention because of the high time resolution. With the development of science, EEG technology which had been used in neural and cognitive psychological research as a clinical diagnosis, also has been applied to the treatment of neurasthenia and other diseases. Some portable EEG acquisition system as household medical equipment have also begun to be used in ordinary families. The purpose of this paper is researching a kind of portable and stable in performance EEG acquisition system which will be used in BCI experiment and daily family application.This system mainly includes integrated analog front end and digital part. This system adopts the integrated analog front end instead of integrated operational amplifier to build amplifier and the AD conversion circuit. It ensures the performance of the system on one hand, on the other hand also reduces the power consumption and volume of the system. This system adopts the high performance DSP as the control core to ensure the stability of the system’s performance. What’s more, it employs USB2.0 as the data transfer protocol to ensure the rapid and accurate transmission of multi-channel’s data. In the aspect of software design, this system optimizes the PC collection procedures and adds the digital filter program which saves hardware cost, reduces the hardware price and ensures the performance of the system.In order to verify the performance of the system, some of its performance indexes were tested which shows that this system matches the needs of the portable EEG acquisition system basically. Meanwhile EEG experiment has been conducted in order to ensure it can be used in the EEG acquisition. The system can collect the basic EEG signal-alpha waves. The results shows that this system can be used in simple BCI experiment and household applications.