Research On Portable ECG Detection System

The development of related cardiovascular diseases is very rapid and its mortality rate is very high. The economic development of society and the health of human being are threatened. The hardware load of traditional portable ECG machine is large and its price is very expensive. So we study an ECG machine which can step into the market extensively in this paper. The ECG machine contains a portable ECG detecting system which can separate the ECG signal acquisition and the ECG signal filter processing.In this paper, we combine today's market mainstream Android smartphone to improve portable ECG instrumentation in the traditional sense. The hardware part of the portable ECG detection system in this paper is only responsible for ECG signal acquisition. Post processing of ECG signal are carried out by an Android smartphone. And the data transmission between the two is via Bluetooth to carry out.In the part of ECG signal acquisition hardware, the main research is the sele ction of the ECG acquisition chip, the main chip and the Bluetooth module and p ower management. In this paper, we choose the ECG acquisition chip is ADS1291, the main chip is STC15L2K56S2 and Bluetooth module is BMX-03 B. The pap er also gives a peripheral circuit principle diagram of each part and the connectio n of each other.The main research of the software part of the ECG signal acquisition is the communication mode between ECG acquisition chip and main control chip, the communication mode between the main control chip and Bluetooth. And the flow chart and key code is given in this paper. The communication between STC15L2K56S2 and ADS1291 is through SPI and between STC15L2K56S2 and BMX-03 B is via UART.The main research of digital filtering of ECG signal is to remove the baseline drift and EMG interference. The algorithm of removing baseline drift is using all pass filter to reduce low pass filter. The algorithm of removing EMG interference is low pass filter with integer coefficients based on the zero and pole points. Then this paper shows the ECG after treatment.This paper also studies the R wave and QRS wave detection of ECG signal. The method is make the differential to ECG signal processed, and then go to the square and move window integration, finally conducting the threshold comparison. This paper also gives heart rate according to the detection of R wave. Then it analyzes the arrhythmia. The last, the flow chart of Android system is given.This system is easy to operate, and can continue to upgrade.It is useful in prevention and diagnosis on the cardiovascular disease.