摘要
目的:针对现有脑电采集系统受限于传输速率低而导致的采集通道数少、采样频率及有效位低等问题,设计一种多通道高性能脑电信号采集与传输系统。方法:该系统在传统"右腿"驱动放大链路中,加入基于RC零极点补偿技术的前馈电路,提高整体链路的环路稳定性;基于高速现场可编程门阵列芯片(field programmable gate array,FPGA)与4片DDR3,设计了2条实时并行处理的"乒乓"交替数据吞吐机制,以提升系统可承载的实时采集通道数。结果:该系统增加了前端模拟链路的相位裕度、增益、稳定性及工频抑制能力,实现了吞吐率达千兆比特的数据整合与高效传输,大幅提高了系统所能承载的通道数量、采样频率及有效位。最终系统实现性能指标为:链路共模抑制比130 dB,有效位24 bit,单通道采样频率500 kHz,传输速率3.125 Gbit/s。结论:该系统可承载256通道大规模采集,尤其可为在非开颅情况下脑部病灶的精确定位诊断提供一套解决方案,为生物学及脑机接口等前沿研究提供有力支撑。
Objective To design a multi-channel high-accuracy electroencephalogram acquisition and transmission system to solve the existing problems in low channel number, sampling rate, significant bit and etc. Methods The system adopted the feedforward compensation technique to increase the phase margin and gain of the loop in the ＂right leg＂ feedback stabilization loop, which could improve the stability of the front-end link and the suppression of power frequency signal. Also,the system used field programmable gate array（FPGA） and 4 DDR3 s to constitute a gigabit network communication system with the ping-pong cache mechanism, which could greatly enhance the number of channels, sampling rate and significant bit of the system. Results The system enhanced greatly the phase margin, gain, stability and ability for power frequency suppression, realized data integration and high-efficiency transmission with gigabit-grade data throughput rate, and increased the maximum channel number, sampling rate and significant bit for the system efficiently. The measured results showed that, the front-end link hadthe parameters of 130 d B CMRR, 24 significant bit, 500 k Hz channel SR, 80 d B effective gain and 3.125 Gbit/s transmission rate. Conclusion The system can be used for 256-channel large-scale signal acquisition,and facilitates the precision diagnosis of brain lesions as well as the frontier researches in biology, brain-machine interface and etc.
作者
赵明剑
陈梓庆
詹艺宇
周哲
ZHAO Ming-jian1,2, CHEN Zi-qing1,2, ZHAN Yi-yu1,2, ZHOU Zhe1,2(1. School of Electronic and Information Engineering, South China University of Technology, Guangzhou 510640, China; 2. National Engineering Technology Research Center for Mobile Ultrasonic Detection, Guangzhou 510640, China)
出处
《医疗卫生装备》
CAS
2018年第7期7-11,共5页
Chinese Medical Equipment Journal
基金
国家自然科学基金(61601188)
广东省自然科学基金(2014A030310372)
关键词
脑电波
右腿驱动
高速采集
现场可编程门阵列
共模抑制比
EEG
driven-right-leg （DRL）
high-speed acquisition
field programmable gate array
common-mode rejectionratio
