Implementation of Phase-tagged SSVEP-based BCI using Comb Filter

• Main Authors: Chih-I Sun, 孫智億
• Other Authors: Po-Lei Lee
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/78899891124360931981

碩士 === 國立中央大學 === 電機工程研究所碩士在職專班 === 98 === This thesis mainly designs as a brain computer interface (BCI) system for electroencephalogram (EEG) of steady state visual evoked potential (SSVEP). Since users gaze at different spatially separated flash channels (FCs) in order to induce visual evoked signals, the BCI provides four fixed frequency but different phase encoding in the flickering source. The Algorithm uses comb filter in the digital filter easy to implement, keep main frequency and harmonic, and can reduce noise. In order to recognize the command mapping to the gazed FC can be sent out to achieve control purposes, the current design uses event correlation to achieve identify distinct flickering sequences among different FCs. The implementation method is designed the analog EEG capture amplifier and micro control unit(MCU), in order to establish a low cost, small size and fast to recognize BCI system. In this thesis, we have built an four-FC system. The command information transfer ratio(ITR) and detected accuracy are 31.02 bits/min and 91.64%, respectively.