Wristband ECG Signal Processing And Waveform Detection Of QRS Complex

With the rapid development of the society,people’s living standards have gradually improved,and people are paying more and more attention to their health.Among many diseases,cardiovascular disease is the first cause of death in urban and rural residents.There are many kinds of cardiovascular diseases,the causes are complicated,and the onset time is fast.The potential diseases that are difficult to detect may cause irreparable damage.Therefore,the ECG monitoring equipment with portable and detectable ECG signals has emerged.ECG monitoring equipment can obtain ECG signals in real time,and perform automatic analysis and diagnosis.Among the various portable ECG monitoring devices that have appeared on the market,wristband ECG equipment has become a first choice because of its small size and can be carried around.Based on this background,this paper analyzes and studies the wristband ECG signals.The treatment of the wristband ECG signal is mainly divided into four steps.First,evaluate the quality of ECG signals.Second,pre-process the acceptable ECG signals,suppressing various interferences in the signal and enhance the noise reduction of the signal.Third,detect feature of the preprocessed signal.Fourth,automatically diagnose based on the detected characteristics of the ECG signals to determine whether the current human body has certain cardiovascular diseases.The research in this paper is to pre-process ECG signals and detect QRS complex based on quality assessment.The pre-processing and detection algorithms will be validated in the MITBIH arrhythmia database and then will be tested on wristband ECG signals.The main work of this paper is as follows:(1)Studying the wristband ECG signal,analyzing the amplitude frequency of the clean ECG signal and the amplitude frequency of the ECG signal containing interference,and discussing the interference including motion artifact,baseline wandering and electro-surgical and muscle contraction artifact,respectively.What is the waveform of the wristband ECG signal? These analysis of the wristband ECG signal helps to achieve targeted interference suppression and noise reduction enhancement of the ECG signal,saving time and computation.(2)Three common filtering methods are introduced and compared for the baseline wandering and electro-surgical and muscle contraction artifact contained in the wristband ECG signal: morphological filtering,wavelet transform and EMD.In the interference suppression stage,an interference evaluation index based on the power spectrum of the ECG signal is introduced,so that the interference signal is reasonably suppressed in a targeted manner.(3)The noise reduction enhancement of ECG signals is studied using a nonlinear adaptive filter.After discussing the Volterra adaptive filter and the PNIIR adaptive filter,an improved PNIIR adaptive filter combining these two filters is proposed.Experiments show that the improved PNIIR adaptive filter has better noise reduction enhancement effect on ECG signals.(4)In the aspect of detecting QRS complexes of ECG signals,this paper proposes a new feature detection idea.The combination of morphological and differential ideas can detect the periodic boundary points of ECG signals as an auxiliary condition for feature detection.The main idea of the algorithm is to divide the period and then perform the QRS complex detection in the period.The test proves that this method effectively reduces the rate of missed detection and false detection to a certain extent.