Research Of Blood Pressure Detection Method Based On The Integration Of ECG And PPG

Blood pressure is one of the important parameters to measure the human cardiovascular system, and it has an important significance for disease diagnosis, treatment process and prognosis estimate. At present, the clinic always uses of intermittent measurement methods such as Korotkoff to measure the blood pressure. This method can only obtain the human blood pressure value for one moment and it is difficult to do monitoring real-time, and the measured blood pressure values are affected by many factors, such as emotion, stress, exercise, etc. The continuous measurement of blood pressure can be very effective in preventing the cardiovascular and cerebrovascular vascular diseases, and this provides a sufficient basis for clinical diagnosis and post-treatment, in particular, it has important practical significance for observing the trend of continuous blood pressure in the clinical care and other special circumstances. At present, non-invasive continuous blood pressure measurement methods have a high requirement for the experimental conditions. For this situation, this study focuses on the relationship between the pulse wave propagation time and arterial blood pressure, and then to prove feasibility of the method to calculate the human blood pressure with the pulse wave transit time (PWTT).In this paper, with the acquisition of the electrocardiogram (ECG) signal and photoplethysmography (PPG) signal, and use the algorithm that separate the fusion signal between ECG and PPG by beat to separate the simultaneous ECG and PPG signals, and using the improved median filtering algorithm to eliminate high-frequency interference between ECG and PPG signals, and using the baseline drift algorithm witch based on WT to eliminate the signals baseline drift that caused by the human body s jitter and respiratory, and using the differential threshold value method to extract the envelope between ECG and PPG signals and obtain the feature points for calculate the pulse wave propagation time, then calculate the pulse wave propagation time. For that, this paper gathered number23samples blood pressure that before and after exercise and PWTT from Northeastern University in Shenyang City Gym, and then do correlation analysis and regression analysis for the data to construct a correlation larger regression equation between the systolic blood pressure and PWTT, and using cross-validation method to test the error of this equation. Taking into account the differences between individuals, this paper did a30-minute tracing for three individuals blood pressures during exercise and the change of PWTT, by statistical analysis of the individual’s blood pressure and PWTT, we obtained individual systolic blood pressure calculation model. Finally, for one subject, we use these two computational models to calculate the systolic blood pressure value, respectively, and compared with the actual value of the systolic blood pressure. The experiments show that, there is a linear relationship between human systolic blood pressure and PWTT, and we can estimate the human systolic blood pressure by PWTT, but due to the individual differences, individual models are not the same.