基于EMI硬化放大器的脑电信号采集系统

EEG Acquisition System Based on EMI Hardened Op Amp

针对非屏蔽环境下的脑电信号采集,基于精密仪表放大器及EMI硬化放大器设计了前端调理电路,包括前置放大级、右腿驱动电路、陷波放大级以及低通放大级,实现了EEG可视化放大的同时较好地抑制了电磁干扰。经调理的模拟EEG由内嵌Sigma-delta ADC的微控制器进行采样量化并传输至上位机。基于Lab VIEW的上位机采集软件完成EEG的在线滤波以及实时的时、频域波形显示。实验结果表明,该系统能够有效地实现EEG的高精度、高质量的提取。

Aiming at the acquisition of EEG in unshielded environment,based on the precision instrumentation amplifier and EMI hardened operational amplifier,the front-end conditioning circuit is designed,which includes instrumentation amplifier input stage,right leg driven circuit,high-pass notch amplifier stage,low-pass amplifier stage,and the front-end conditioning circuit realizes the visualization of the EEG signal as well as suppression of the electromagnetic interference.The conditioned EEG is sampled and quantified based on the MCU which embedded Sigma-delta ADC,at the same time,the MCU completes the format conversion of the EEG and transmits it to the upper monitor.And the acquisition software based on LabVIEW complete the online filtering of the digital EEG and displays the frequency domain and time domain waveform of the signal.The result of the experiment indicates that the system can effectively implement the high-quality and high-quality acquisition of the EEG.