Research On Wearable Twelve-Lead ECG Monitoring System And Motion Artifact Suppression Method

Cardiovascular diseases are a serious threat to human life and health.With the acceleration of population aging and the increase of social pressure and other factors,the prevalence of cardiovascular diseases is increasing year by year,and the age of onset tends to be younger.However,most cardiovascular diseases are caused by organic lesions of organs,and it is difficult to recover completely once diagnosed.Thus,long-term monitoring and prevention is required.Electrocardiogram(ECG)is one of the most important methods for diagnosis of cardiovascular diseases,but currently available portable ECG monitoring devices have few leads,and the operation is complicated,so it is not convenient for daily use.In view of this,a wearable 12-lead ECG monitoring system is designed to realize 24-hour continuous real-time monitoring of dynamic ECG signals.The main research contents of this thesis are summarized as follows:(1)According to the actual demand of wearable 12-lead ECG monitoring system,a wearable ECG monitoring terminal with small size,low power consumption and comfortable wearing is studied and designed.The composite fabric dry electrode is selected to design the ECG monitoring garment to improve the comfort of long-term wearing.The hardware circuit is designed with low-power controller TM4C123GH6 PM,highly integrated 24-bit analog front-end chip ADS1298,motion sensor MPU6050 and other components to realize real-time acquisition of ECG signal and motion status signal.The SD card is used for data storage and wireless data transmission is performed with the client through low-power Bluetooth.The power management and voltage regulator circuit are designed to improve the power stability and safety of the device.(2)The embedded software and ECG monitoring client are designed based on the wearable ECG monitoring terminal.The embedded software contains drivers for acquisition of ECG signal and motion state signal and other module drivers.And the data format is customized to ensure the reliability of wireless transmission of the data.The ECG monitoring client enables real-time dynamic rendering of ECG waveform,calculation and display of heart rate,and alert of lead abnormality,etc.The collected data can be saved to the local database for management after logging into the client with an account,and meanwhile it can be uploaded to the cloud platform for data cloud storage and establishment of personal health records.(3)Since the wearable ECG monitoring device used in the motion scenarios is prone to disturbed by motion artifact noise,a motion artifact removal method is proposed based on variational mode decomposition and adaptive noise canceller.The human motion signal and noisy ECG signal are decomposed by variational mode decomposition,and the signal components that are highly correlated with the noise are extracted for construction of the acceleration signal,which is used as the reference signal of the adaptive noise canceller.The filtering performance is improved by enhancing the correlation between reference signal and noise signal.And experimental results in different motion states demonstrate the effectiveness of the method.Finally,the wearable 12-lead ECG monitoring system designed in this thesis is tested,and its performance parameters and software functions meet the design requirements and relevant standards.The system achieves good performance in actual application.