A Study On A Portable ECG System For Acquisition And Analysis Based On STM32 And Bluetooth 4.1

Heart disease remains one of the major diseases that threaten human life, with the highest mortality rate the wold. According to statistics, among all the death in the world, ont third of them died of such disease. Therefore, the diagnosis and prevention of heart disease is a major problem of the medical field, and the ECG acquisition, analys and diagnosis is particularly important. Based on the needs above, this article designed a set of ECG signal acquisition, wireless thransmission, analysis and processing system.First, lower machine system uses STM32F103RET6 as the core part. The system includes power module, acquisition module, control module and Bluetooth module. Through SPI interface, the main chip STM32F103RET6 controls acquisition chip ADS1298, and complete amplification, filtering, common mode rejection and A/D analog-digital converter of the collected ECG signal. The system connects the Bluetooth chip RN4020 via UART interface of the main chip. Therefore, complete ECG transmission to the upper computer under the Bluetooth communications protocol.And then, the upper computer realizes the communication with the lower machiner, using PC under windows environment. The analysis system developed programs under Visual Studio2010 environment using C #. Firstly, the system processes the collected ECG data, including ECG data lead conversion. Transform the 8 pilot data into 12-lead data; display multi-lead ECG waveform, analyze the ECG parameters, generate ECG reports and ECG data tables in PDF and JPG format, patient information management, storage of ECG data using SQL databases, wireless transmission of patient information and ECG reports using Socket network.Finally, the article has done some theoretical research including digital filtering and major waveform recognition. In this article, limit breadth filter is used to filter out the pulse interference signal, the FIR digital filter to filter out the work of 50 hz frequency interference signal, the signal after filtering recursion average filtering method is adopted to improve the smooth. And, select the singular values of wavelet transform to identify the R-wave peak point, and, continuous wavelet transform(CWT) to locate the QRS complex waveform, T wave and P wave. And, generate DLL dynamic link library in C ++, finally, use the DLL in the upper desk using C# language, realize the analysis. There is a need to verify the acquisition and analysis system. In this article, use MPS450 produces various types of abnormal ECG signals to verify the the accuracy of analysis System. Thus, validate the entire acquisition and analysis system is rational and available.