Design And Implementation Of Multilead ECG Acquisition System

Nowadays, more and more people concern about health, but the incidence of heart disease is more and more high that threats human life, has become one of the main diseases causing death. Therefore, for the prevention of heart disease, early diagnosis and treatment become an urgent need. While activity information of the heart system can be represented in the electrocardiogram(ECG) signal, therefore, to obtain the ECG signal has become an important means of diagnosis of heart disease.This system realizes the function that acquires ECG signal from human body, and can monitors the patient’s ECG signal which come to clinic, nursing homes and family in rural units etc, can also through the remote transmission module transmit acquired ECG signals to the remote monitoring center where medical personnel can be used for further analysis and diagnosis. The ECG acquisition system mainly consists of hardware and software part.The hardware part consists of four units: the front-end signal acquisition circuit, A/D conversion circuit, digital signal processing circuit, D/A conversion circuit. The function of front-end signal acquisition circuit is isolate the original ECG that obtained from the leads, multistage amplifier and filter, in order to further satisfy the requirement of signal amplitude for A/D conversion. A/D conversion circuit is composed of the ADS1298 chip, the chip is TI devices dedicated to the processing of ECG signal, Seting up the TMS320VC5416 MCBSP channels to SPI mode, controling ADS1298 transforms and receives data. Digital signal processing is realized by FPGA, the converted digital signal by DSP IO port sent to FPGA filtering. The D/A conversion chip is DAC8560, converts the digital signal into an analog signal after signal filtering.The software part of the system is mainly to complete the following functions: Assembly language and C language used for configuring DSP MCBSP port for receiving ADS1298 conversion data. THE data is sent to the FPGA, VHDL language used to write the FIR filter and adaptive filter for filtering out the 50 Hz interference. FPGA is used to control the DAC8560 convert digital signals to analog signals for actual testing.Through the front-end processing circuit and digital filter processing, the high noise and interference is filtered, can get useful ECG signal for the medical staff analysis and process, it can be seen from the simulation and the actual test results, the adaptive filter in the filter power frequency interference has better effect than the FIR filter.