摘 要

脑电信号是人体重要的生物电信号，通过采集人体脑电信号，可以分析生理和病理信息，甚至可以通过脑电信号控制一些设备，如机械手臂。通过对脑电信号的研究，我们能够了解脑神经细胞的电位活动与人思维的关系，进一步讲，可以分析到大脑所想。

我们都知道，脑电信号作为生物电信号很微弱且背景噪声强，是一种非平稳性突出的随机生物电信号，只有通过大量的实验数据才可以得到统计结果，并用于诊断。本文为了采集脑电信号，设计了调理电路去除背景噪声、工频干扰等无用信号，并采集到微伏级别的的脑电。

本文主要内容：

1. 脑电信号产生与分类，电极导联与安放；
2. 脑电信号调理电路设计：前置放大，50Hz陷波双T滤波器，四阶巴特沃兹低通滤波器，二阶巴特沃兹高通滤波器，无源高通滤波器，后置放大，电平抬升等；

脑电信号采集电路设计：STM32F407开发板，发光二极管，TFT-LCD显示屏，STM32内部12位AD及外围电路；

1. 脑电信号下位机软件设计：编写程序用于数码管点亮，AD采样，串口发送，LCD显示屏显示；上位机软件设计：使用Labview接收串口发送的数据，实时脑电波显示，并保存波形图片，以及脑电信号的电压数据存储到Excel表中；
2. 脑电采集实验数据及波形。

关键词：脑电信号，调理电路，STM32F4，Labview

Abstact

EEG signal is an important human bioelectricity, through the acquisition of human EEG ，we can analysis of physiological and pathological information, even though the EEG signals control some equipment, such as mechanical arm. Through the study of the EEG signal, we are able to understand the relationship between nerve cells in the brain electrical activity and thinking, to analysis what the brain think. 

As we all know, EEG signal as a biological signal is very weak and has strong noise background, is a protrusion of the non-stationary random bioelectricity signal, only through a large number of experimental data can we obtain the statistical results.It is used for diagnosis. This paper for EEG signal acquisition, conditioning circuit to remove background noise, power frequency interference and other undesired signal, and collecting microvolt level of EEG. 

The main contents of this paper: 1, EEG signal generation and classification of electrodes and placed; 2, brain electrical signal conditioning circuit design: pre amplifier, double T 50Hz notch filter, four order Butterworth low-pass filter, two order Butterworth high pass filter, passive high pass filter, amplification, level elevation; EEG signal acquisition circuit design: stm32f407 development board, light-emitting diode, TFT-LCD display, STM32 12 ad internal and external circuit; 3, the design of lower computer software of brain electrical signal: write a program for digital tube light, AD sampling, serial port, LCD display; PC software design: use LabVIEW to receive the serial port to send data, real-time EEG display, waveform and save the picture, and the voltage data storage of EEG signals to the excel table; 4, EEG experimental data and waveform; 

Keywords: EEG, conditioning circuit, stm32f4, LabVIEW 

目录

1. 绪论.........................................................1

1.1脑电采集的背景及研究的目的和意义.............................1

1.2脑电采集的发展现状与分析.....................................1

1.3本课题结构安排...............................................2

1. 采集方案.....................................................3

2.1脑电信号产生.................................................3

2.2脑电波形图与分类.............................................3

2.3脑电极.......................................................4

2.4干扰.........................................................5

2.5脑电采集系统设计方案.........................................6

2.6小结.........................................................7

1. 硬件电路.....................................................8

3.1INA128前置放大电路...........................................8

3.2陷波滤波电路.................................................9

3.3巴特沃兹低通滤波电路........................................11

3.4无源高通滤波与二次放大电路..................................12

3.5三次放大与无源高通滤波电路..................................13

3.6直流电平抬升电路............................................14

3.7联调........................................................15

3.8 选择MCU-STM32F407..........................................16

3.9 RS232串口与串口通信........................................18

3.10 ADC........................................................19

3.11小结.......................................................19

第4章 软件设计....................................................20

4.1基于STM32的下位机设计......................................20

4.1.1 配置串口..............................................20

4.1.2配置与使能AD..........................................21

4.1.3 AD与串口通信主函数....................................21

4.2上基于LabVIEW的上位机设计..................................21

4.2.1 Labview与VISA驱动....................................21

4.2.2脑电采集的LabVIEW上位机前面板.........................22

4.2.3 脑电采集的LabVIEW上位机显示程序......................23

4.3小结........................................................24

1. 总结........................................................25

5.1脑电波形数据显示与分析......................................25

5.2结论........................................................26

5.3展望........................................................26

参考文献...........................................................28

致谢...............................................................29

附录