Extraction And Optimization Of Ballistocardiograms' Beat-to-Beat Interval

Many healthcare applications require the use of the instantaneous frequency of the heart rate signal,the reliability and accuracy of which are crucial.In the current medical industry,most of the mainstream cardiac function testing devices have one common defect that requires professionals to perform cumbersome operations on professional equipment,and the electrodes need to be directly mounted on the fixed parts of the patient's body.Therefore,the heart function testing equipment to transform and enhance its portability and ease of installation has now become the main problem.In recent years,studies have found that the application of the heart impact plot signal can effectively solve this problem.A new and flexible algorithm is proposed to calculate the center jump spike interval of the Ballistocardiograms(BCG).Experimental subjects in the use of vertical sit-up position,to avoid the body caused by human motion and other noise.The data used in the experiment was taken from a piezoelectric thin-film sensor strip and the raspberry pie was used to process the collected signals.Since there is a lot of noise interference in the collected signal,Butterworth filter is used to filter the noise.The first step in signal processing is the use of window analysis,where you do not need to find the location of each heartbeat peak as usual and calculate the interval between heartbeat peaks directly using window analysis.The results of the treatment there are still a large number of abnormal points,the accuracy rate of about 90%,can not achieve the desired.Followed by the addition of Gaussian normal distribution and median filtering to eliminate noise.Finally,the correctness and credibility of this proposed algorithm are verified through experiments.Experimental data collected using finger-stick oximeter as a control.After several treatments,the number of outliers in the resulting signal is getting smaller and smaller,the overall signal trend is very high with the control group,and the beat-to-beat interval can be well obtained.Therefore,the experimental data collection and analysis results show that the proposed method of extracting beat-to-beat interval is a credible method of processing,which can accurately calculate the real-time heart rate of the examinee.