System Design, Based On The Arm7 And The Uc / Os-ii Portable Ecg Analysis

Cardiac disease is one of the major diseases that endanger human's health. Electrocardiogram (ECG) is a synthetic reflection of the heart electricity on human body surface, and it is very valuable to diagnose the heart disease. function.So it is valuable to design a portable ECG analyzing system to monitor patients.This paper introduces the portable ECG analyzing system.In order to realize the dynamic display and analysis of ECG,the low-power 32 bit ARM processor LPC2214 is used as the kernel of the system,and UC/OS—II is used as the embedded operating system.Circuits of the designed system consist of two parts,ECG data amplifying and acquiring circuits and the kernel digital module circuits.the former consists of four parts: three-lead amplifying circuits, driven-right-leg circuit, digitally isolated circuit and AD acquiring circuit.The function is to adjust the lower signals to acquire the valuable analog ECG signals,then they are converted to digital signal.the latter also consists of four parts: ARM7 microcontroller LPC2214,LCD MZT24-1,SRAM,SD Card and RTC DS1302. The function is to realize system-control, real-time analysis of acquired ECG data, display the analysis results and ECG waveform on the LCD; in addition, write the acquired ECG data in SD card to out-of-time analyze,set up the time when the system sets to work to help doctors and patients mark the time when they acquire the ECG signal. The modular method on the basis of function is used in programming,which makes the system has good reusability and expandability.In the design of digital notch filter, using the method of cascaded second-order section, saving memory space and computing time, improving the process reusability, realizing real-time filtering, well filtering 50HZ interference.The hardware and software of the portable ECG analysis system are designed in this paper.The tested results show the system has achieved goals such as ECG signal real-time acquisition and analysis,ECG waveform real-time displaying,recording and replaying ECG signal and setting the system time etc,which provide the basis for the new ECG signals processing instrument.