毕业设计_心电检测完美

目录摘要

第一章绪论…………………………………………第二章工作原理……………………………………

§2.1 总体设计…………………………………

§2.2 心电信号的检测及采集……………………第三章原理设计与方案论证………………………

§3.1 高频滤波电路………………………………

§3.2 心电信号放大电路…………………………

§3.3 陷波电路…………………………………

§3.4 AD转换……………………………………

§3.5 存储器………………………………………

§3.6 程序设计……………………………………第四章器件介绍………………………………………

§4.1 生物电引导电极……………………………

§4.2 仪表放大器AD623……………………………

§4.3 AD转换器ADC0809……………………………

§4.4 LM324 ………………………………………

§4.5 AT24C64 ……………………………………

§4.6 DA转换器 DAC0832……………………………

§4.7 MCS-51 ………………………………………第五章信号干扰及其预防措施………………………总结……………………………………………………致谢……………………………………………………参考文献…………………………………………………附录…………………………………………………附录一……………………………………………………附录二……………………………………………………1 2 2 2 5 5 5 7 9 10 10 14 14

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摘要

本论文介绍了一种体积小巧的心电检测仪的设计过程。此仪器由于具有存储心电信号和回放心电信号的功能。因此出于体积方面的考虑，仪器主要选择了体积小，功耗低的器件。例如：小体积的仪器放大器AD623和I2C总线结构的EEPROM AT24C64。控制部分选用技术成熟的MCS-51系列的微处理器，此处理器功能强大，还具有节电功能。心电信号的最高频率为125Hz。根据采样定理，采样频率应大于250Hz，在此设计中采样频率为250Hz，所以AD转换器选用了速度更快的逐次逼近式AD转换起ADC0809。DA转换器为DAC0832，它的分辨率与ADC0809相同都是8位的，电流输出稳定时间为1µs，完全符合系统的要求。EEPROM AT24C64的存储容量达8K字节，在250Hz采样频率的情况下可存储30s左右的心电信号。该心电检测仪，性能稳定，抗干扰能力强，完全能够满足一般的家庭应用，具有广阔的市场前景。

关键词：心电检测 50Hz陷波器 AD转换器 DA转换器仪表放大器

Abstract

This paper introduce one small and exquisite heart electric design process of detector.This instrument stores the electric signal of heart and goes back to rest assured about the function of the electric signal. In consideration of volume, the device has been chosen mainly smallly, the device of the low power dissipation. For example: Small instrument amplifier AD623 and I2C bus EEPROM AT24C64 of structure of volume.The microprocessor selecting MCS-51 series with ripe technology for use partly, this processor is powerful, and is economize on electricity functions to have also. The supreme frequency of the electric signal of heart is 125Hz. According to the theorem of sampling, sampling frequency should be greater than 250Hz, in this design sampling frequency is 250Hz, so AD converter has selected approaching type converter ADC0809 of AD one by one more quickly of speed for use. DA converter for DAC0832, resolution ratio of 8 bit, electric current output steady time 1 μs, totally accord with the systematic request. The memory capacity of EEPROM AT24C64 reaches the byte of 8K, can store about 30s of electric signals of heart in case of 250Hz sampling frequency. This electric detector of heart, performance is steady, anti-interference ability is strong, the family application that can be satisfied and general, have wide market prospects.

Keywords: The heart electricity measuring 50Hz falls into the wave device AD Converter DA Converter Instrument amplifier