心电采集电路的设计与实现论文

编 号： 审定成绩：

重庆邮电大学 毕业设计（论文）

设计（论文）题目： 心电采集电路的设计与实现 学 院 名 称 ： 生物信息学院

* * * * ： * *

专 业 ： 生物医学工程

班 级 ： 0611003

学 号 ： * * * * ： ***

答辩组 负责人 ： 王 伟

填表时间：2014 年 5 月 重庆邮电大学教务处重庆邮电大学本科毕业论文 I 摘 要 随着社会进步，科技发展，人们所受到的心血管疾病的威胁不但没有下降反而有所增加，比如白领猝死等问题。因此，有必要也有需要设计一款心电采集设备，时时监测个体的心脏工作状态，预防心脏疾病的发生。 心电信号(简称ECG)一般受到基线漂移、工频噪声及肌电噪声的干扰。由于ECG信号是强噪声下的低频微弱信号，因此在提取ECG信号时必须进行滤波及放大处理。本课题设计了一款ECG信号采集电路，实现对ECG信号的提取。主要工作如下： ①查阅相关文献,全面分析了解ECG信号特征，为论文工作的展开做准备。 ②结合ECG信号的特点，提出ECG信号采集电路总体设计方案。 ③设计硬件电路。分为电源模块、放大模块和滤波模块.其中滤波模块包括80Hz低通滤波、0.5Hz高通滤波及工频陷波器。 ④使用Multisim10.0仿真放大与滤波电路，进行调试。 ⑤用面包板搭建各电路模块并分别调试，然后总体调试。测试通过后用万用板焊接，最终保证电路能够正常工作。 ⑥绘制PCB板，焊接电路及调试电路，保证电路稳定工作。 本课题设计的ECG采集电路能够提取到稳定的ECG信号，虽然仍受到部分噪声干扰，但是总体来说所得到的 ECG信号还是比较清晰稳定的，可以运用于以后扩展功能，如特征值提取及预防猝死等应用。

【关键词】心电信号 低频信号 噪声干扰 硬件电路 重庆邮电大学本科毕业论文

II ABSTRACT With social progress and technological development, people are subjected to the threat of cardiovascular disease has not decreased but increased.，such as white-collars suddenly catch the death. Therefore, it is necessary that we should design an ECG acquisition system to constantly monitor the status of individual cardiac work and prevention of heart disease. ECG signals (abbreviated ECG) are generally disturbed by baseline drift, industrial-frequency noise and interference EMG frequency noise. Since the ECG signal is weak low-frequency signal, so when extracting the ECG signal, filtering and amplificatory process must be carried out. This paper designed an ECG signal acquisition circuit to extract the ECG signals. The main works are listed as follows: ①Searching relevant literatures prepares and comprehensively analyzing the ECG signal characteristics are done for the launch of the paper work. ②Combining with the characteristics of ECG signal, the design of ECG signal acquisition circuit program was proposed. ③Hardware was designed. It included the power module, amplifier module and filter module. Filter module includes 80Hz low-pass filtering and 0.5Hz high-pass filtering. ④The amplification and filtering circuit were simulated with Multisim10.0, then debugged. ⑤Every circuit module was set up with breadboard, debugged. Then all modules were debugged. After the test, universal plates were welded to ultimately ensure that the circuit works properly. ⑥PCB board was drawn; Circuits were soldered and debugged to ensure circuit stability. The designed ECG acquisition circuit of this passage can extract a stable ECG signal,. Though there still are many noises, overall, the obtained ECG signal is quite clear and stable, applied to future expansion capabilities, such as extracting eigenvalues, preventing suddenly death and other applications.

【Key words】ECG Low- frequency signal Noise jamming Hardware circuit 重庆邮电大学本科毕业论文 III 目 录 摘 要............................................................................................................................ I ABSTRACT .................................................................................................................. II 目 录............................................................................................................................ III 第一章 绪论.................................................................................................................. 1 第一节 课题研究的背景 .......................................................................................... 1 第二节 研究动态 ...................................................................................................... 2 第三节 研究意义及应用前景 .................................................................................. 2 第四节 本章小结 ...................................................................................................... 3 第二章 心电信号相关理论.......................................................................................... 4 第一节 ECG信号分析 ............................................................................................. 4 一、ECG信号的形成生理机理 ........................................................................... 4 二、ECG信号的特点 ........................................................................................... 5 三、信号特征分析 ................................................................................................ 5 第二节 ECG信号所包含噪声分类及处理方法 ..................................................... 7 第三节 本章小结 ...................................................................................................... 9 第三章 心电采集硬件电路设计................................................................................ 10 第一节 心电采集模块的总体硬件设计 ................................................................ 10 一、系统硬件电路设计原则 .............................................................................. 10 二、系统建模 ...................................................................................................... 11 三、系统前置放大电路的设计要求 .................................................................. 12 四、系统滤波器的设计讨论 .............................................................................. 13 第二节 ECG采集硬件电路具体设计 ................................................................... 15 一、ECG信号的拾取 ......................................................................................... 15 二、ECG采集信号放大电路的设计 ................................................................. 15 1、前置放大电路设计..................................................................................... 16 2、二级放大电路设计..................................................................................... 18 三、ECG采集滤波电路设计 ............................................................................... 19 1、滤波器元器件选择标准............................................................................. 19 2、50Hz陷波器电路设计 ............................................................................... 19 3、0.05Hz到100Hz带通滤波器电路设计 ................................................... 21 四、电源单元 ...................................................................................................... 26