Design Of Portable Electrocardiogram Detector

The cardiovascular disease has become a major threat to human health. ECG is an important basis to diagnose cardiovascular disease and plays a significant role in the clinical diagnosis field. The hospital’s electrocardiograph has the shortcomings of immense size and working place limitation, and the portable ECG detecter sold in the market generally use the cable to transmit ECG data. This paper designs a portable ECG detector which based on bluetooth4.0 protocol.The detector consists of ECG detection part and PC receiving part. The ECG detection mainly complete gathering and processing the ECG signal, LCD displaying, SD storing and bluetooth communicating. The PC receiving part mainly complete designing PC software.According to the feature of ECG, this paper designs the ECG acquisition modular circuit including the preamplifier circuit reducing common-mode interference, filter circuit eliminating the noise outside of the band, main amplifier circuit amplifing the ECG singnal a, level uplift circuit. The high-performance, low-power processor STM32F429 by ST is choosed to design the core control circuit including the minimum system controller, LCD interface circuit and SD card interface circuit. The CC2540 chip which compatibles with bluetooth 4.0 protocol is applied to design bluetooth wireless module which can transmit ECG data to host computer. To further effectively filter interference noise, This paper designs filtering program based on FIR filtering algorithm, which can eliminate the interference of 50 Hz nicely.In Qt IDE, the paper uses C++ to design the PC software and realize the function of data acquisition, processing and display real time.After testing, the portable electrocardiogram detector in this paper is convenient to carry and operate, also can detect ECG in real time. Using bluetooth to replace the wire transmission makes the detector more portable.