【作者】 陆松波；

【导师】 阮健； 曹志锡；

【作者基本信息】 浙江工业大学 ， 机械电子工程， 2007， 硕士

【摘要】 本设计针对目前市场上所销售的或医疗机构所使用的心律计信号采集不精确且需多次采集、信号放大倍数不够且具有干扰影响、所得心电图形波形具有毛刺、功耗较高等缺点而提出来的。文中设计了心电放大器的基本电路构成,以及采用TI公司的MSP430系列单片机对心电信号进行模数转换处理的方法,还着重探讨了采用带硬件乘法器的MSP430F449单片机对心电信号进行滤波处理的方法,并给出了相应的实验结果。人体心肌产生的电信号传导到体表之后,由于在体表分布的不同而产生电位差,将这种电压只有mV级别的电位差放大并绘制成图,就得到了心电图(ECG)。心电图在心血管疾病的临床诊断中有非常重要的作用。通常采用的心电图按照导联数分有单导联,三导联,五导联以及十二导联等等;按照精度分常用的有8位和12位精度等等。单导联,精度低的心电图常用于进行心电监控以及心率测量。12位高精度的心电图由于可以反映出心电的细微变化,被更加广泛地应用于临床诊断、心电分析等地方。要把人体心肌产生的电信号进行精确采集,就需要性能优越的传感器,在本次设计中采用0.85UM-0.9UM的红外LED和同样波长的接受器来进行信号采集。由于心电幅度只有mV量级,需要放大上千倍才能被观察到,并且人体的内阻比较大,因此一个高阻抗、高增益的放大器是准确获取心电信号的关键。而周围环境中充满了各种各样的电磁干扰,会严重影响微弱的心率信号,而其中最为严重的是市电电源的50Hz(部分国家为60Hz)的干扰(工频干扰)。如何避免这些干扰也是心电放大器设计所必须考虑的问题。在本次设计中所设计研究的放大器能很好的满足以上要求。此外,进行高精度的AD转换也是关键的步骤,功耗也是需要考虑的因素。TI公司生产的MSP430F43X、MSP430F44X系列微功耗混和信号单片机,由于具有速度快(8MIPS/16bit),集成度高(Flash,RAM,16bitTimer,8通道12bit ADC以及UART等)、极低功耗等特点,因此非常适合于ECG放大器一类的应用。MSP430F44X系列单片机由于具有硬件乘法器,因此具备一定的DSP功能。MSP430F44X系列单片机是目前业界功耗最低的,其超低功耗性能是其他产品无与伦比的。本次设计阐述了该系统的总体结构和工作原理,并对其中的关键硬件芯片MSP430F449进行了介绍和设计,以及分析了系统各部分的设计,最后对该设计系统进行了调试,采集到了图像质量良好的心电图形,具有很好的实用价值。更多还原

【Abstract】 This design designs the heart to give or get an electric shock the basic electric circuit composing of the enlarger, and adoption TI a machine of series of MSP430 of the company carries on the method of the mold number conversion processing to the heart telecommunication number, still emphasized to inquiry into the adoption to take a machine of MSP430F449 of the hardware multiplication machine to carry on a method for waving to the heart telecommunication number, and give homologous experimnt resultOutput telecommunication number of the human body myocardial after conduct the body watch because of in the dissimilarity but the creation potential differences that the body watch distribute, enlarge the potential difference that this kind of electric voltage onlies have the Class of mV and draw diagram, have to arrive the electrocardiogram(ECG),The electrocardiogram has the count for much function in the cardiovascular paroxysm clinic examine a patient.The way of the outlet of the electrocardiogram adoption that usually adopt is divided into the single outlet,3 outlets,5 outlets and 12 outlet etc.s,Divide according to the accuracy to have 8 and 12 accuracy etc.ses in common usely.single outlet, the low electrocardiogram of accuracy usually useds for the heart electricity supervision and Heart rate measure. 12 electrocardiograms of high accuracy is been apply in the clinic to examine a patient more and broadly because of can reflect the small variety of a heart electricity, heart electricity analysis and so on.Because the heart electricity range only the mV quantity class, need to be enlarge up to thousand then can be observe, and the electric resistance of the human body is more and greatly, so a high resistance, high increase the enlarger of the benefit is accurate to obtain the key of the heart telecommunication number. But was filled with the electromagnetism interference of various each kind in the surroundings environment, will affect the weak heart rate signal seriously, But among them the city is most serious to give or get an electric shock the interference of the 50 Hzs of the power supply. How avoid these interferences are also the problems that the heart electricity enlarger design must consider, In addition, the AD conversion that carries on the high accuracy is also the step of the key, the energy consume is also a factor that need to be consider.The MSP430F43X that company of TI produce, the mentally retarded quantity of the MSP430F44X series consumes to mix a machine of signal. Because having the speed quick(8 MIPSs/16 bits), gather a high( Flash, RAM, the 16 bit Timer,8 passages 12 bit ADCs and UART etc.s) and mentally retarded quantity consumes etc. characteristics, therefore very suitable for type applications of enlarger of ECG.A machine of series of MSP430F44X because of having the hardware multiplication machine, so have the certain function of DSP.更多还原