Research And Design Of ECG Filter Algorithm And Early Warning System

Science and technology are the primary productive forces,and its rapid development has greatly promoted and the prosperity of human economic and the country.Advanced science and technology have brought many new methods to the clinical treatment of cardiovascular disease,which greatly improves the therapeutic effect of patients and prolongs the life span of human beings.However,with the improvement of people’s economic level,the pace of life is also accelerating,and the incidence rate of cardiovascular diseases is increasing year by year.Medical workers can diagnose the abnormal condition of heart by analyzing the electrocardiograms(ECG)of patients.However,most people do not have the awareness to do an electrocardiogram before having heart symptoms.Base on this situation,the portable ECG detection devices are designed.In this thesis,the problems of serious motion artifact interference,baseline drift and inaccurate QRS complex recognition in Wearable ECG detection device are explored.Based on low-power components and signal filtering algorithm,a wearable wireless ECG detection system is designed.A comfortable T-shirt is used as a wearable carrier,and a differential lead electrode is embedded and connected to the device through a USB Type-C interface.MOSFET switch circuit is used in the device to switch the power supply state of the system.According to the Bluetooth connection status,the operative mode of the device is switched by software to reduce the power consumption of the system as much as possible.For portable ECG detection device,motion artifact noise and baseline drift will seriously interfere with the location of subsequent QRS complexes.A three-axis acceleration sensor is designed in the hardware of the device,and the collected human acceleration signal is used as a reference quantity.The signal is filtered in real time using an improved adaptive filtering algorithm,and the QRS characteristic wave is located in real time through the differential threshold and slope mutation algorithm,so that the device can stably output ECG signals and heart rate values.Finally,the stability and reliability of the prototype are tested.The results show that the prototype has the advantages of portability,stable work,low power consumption,and battery life is up to 12 hours.The device collects physical signals of many subjects.The results show that the device can have stably ECG and heart rate output signals.Under the conditions of rest R-wave position accuracy is 99% and the heart rate error is within 2%;In the state of exercise,the accuracy of R-wave position is 96% and the heart rate error is less than 4%.In summary,the device has the characteristics of easy wearing,stable output signal and long battery life,and meets the relevant test indicators of portable ECG detection equipment.