高共模抑制比全频段脑电采集系统  

High CMRR Full Spectrum EEG Acquisition System

作　　者：郜东瑞[1] 李鹏霄[1] 陈其友[1] 尧德中[1] 刘铁军[1] 

机构地区：[1]电子科技大学生命科学与技术学院、神经信息教育部重点实验室,成都610054

出　　处：《中国生物医学工程学报》2015年第6期708-713,共6页Chinese Journal of Biomedical Engineering

基　　金：国家重大科学仪器开发专项(2012YQ120046);国家高技术研究发展计划(863计划)(2015AA020510)

摘　　要：为了实时消除脑电信号采集过程中引入的直流成分,提高系统的共模抑制比,拓宽信号的采样带宽,设计一款具有动态直流校正功能的全频段脑电采集系统。通过微处理器读取脑电采集系统中所包含的直流成分,然后将直流成分通过数模转换器反馈到实时直流校正系统,接着实时直流校正系统将处理后的直流分量输出至仪用运算放大器的参考端,并和原有的直流分量进行反相相加,从而实现对直流信号的消除。测试结果表明,该脑电采集系统能够实时消除直流成分,将系统共模抑制比提高至120 d B以上,并实现DC^1 000 Hz的全频段脑电信号采集。因此,该系统能够为使用者提供更加精确的脑电信号,可以用于认知科学的研究、医疗诊断等领域,促进相关领域的进一步发展;而且由于系统电路结构相对简单,可以集成到柔性电路板上,制作成可穿戴医疗监护设备,帮助使用者更好地监测自身生理状态。In order to suppress DC voltage of the raw EEG,and improve common-mode rejection ratio（ CMRR）and broaden bandwidth of the EEG,a full spectrum EEG acquisition system that can dynamically eliminating DC voltage was designed in this paper. DC voltage was acquired by microprocessor,and then the DC voltage was translated into analog signal by digital-to-analogue conversion（ DAC） and fed back to the dynamical eliminating system of DC voltage. The DC voltage was handled by the system,and then DC components were exported to REF of the instrumentation amplifier,and the DC voltage can be eliminated. Test results showed that not only the DC voltage of the EEG acquisition system could suppress dynamically,but also CMRR could be increased up to more than 120 d B,and the full spectrum EEG（ DC- 1000Hz） could be acquired. Therefore the EEG acquisition system could acquire more precise EEG signals and be used for research in cognitive science and medical diagnosis to promote development of brain science. Besides that,because of the simple circuit structure,it could be integrated into flexible printed circuit,and made into wearable medical monitoring device,which can help people monitor their physiological status.

关 键 词：脑电 动态直流校正 高放大倍数 高共模抑制比 

分 类 号：R318[医药卫生—生物医学工程]