Study On The Correlation Between Pulse Features And Blood Pressure

Blood pressure begins to spread in the form of waves along the root of the entire arterial system. And the spread produces the pulse waves. Therefore, the pulse wave propagation is closely related to the mechanical parameters changes of the cardiovascular system. It is not only affected by the heart condition, but also affected by the arterial blood parameters, the characteristics of blood, the skin and so on. In other words, the changes of a series of cardiovascular parameters, such as blood pressure, blood vessels, vascular resistance, vascular flexibility and blood viscosity and so on, can reflect on the pulse amplitude and waveform changes. So, the noninvasive continuous blood pressure measurement using pulse wave parameters, can measure beat-to-beat blood pressure and continuous wave form of arterial blood pressure at a certain period of time. Therefore, this method can provide more sufficient evidence for clinical diagnosis and cure and it has important practical significance, especially in clinical monitoring and observing continuous change of blood pressure in some special conditions.Based on the working principle of pulse image sensor, we establish the finite element model of pulse image sensor. Through the finite element analysis of the model, we can analysis the displacements of the different points on the film, and make the research on the thin film 3D dynamic changes. Further, we can obtain the pulse characteristic parameters. Based on this research, we can make research on the correlation between blood pressure and pulse features, and provides a new means and methods for the noninvasive continuous blood pressure measurement.The main research is to establish the finite element model of pulse image sensor, and to extract pulse features through the analysis of the finite element model. We can establish and analysis the finite element model of pulse image sensor with the software abaqus. Firstly, we extract the pulse waveform of a point on the film under the different pulse pressure through the analysis of the displacement of the point. We can determine the best pulse pressure by the waveform feature. Then, we extract the different pulse waveform of the different points on the film through the analysis of the displacements of the points. We can determine the best position of the point on the thin film by the waveform feature. Finally, we extract the characteristic parameters of the pulse signal in time domain Based on the analysis of the pulse signal in time domain.According to the pulse features which we extract, we make the research on the correlation between and pulse features and blood pressure. Firstly, we make a simple correlation analysis. The pulse features which have good simple correlation with blood pressure are given by the results of the simple correlation analysis. For the further research on the correlation between and pulse features and blood pressure, we make the multiple stepwise regression analysis. The stepwise regression analysis forms three regression equations. Dependent variables of the equations are systolic pressure, diastolic pressure and the average pressure. Independent variables of the equations are the pulse features which are selected by the stepwise regression analysis.Finally, we use the pulse image sensor to collect the pulse single. Then, we can extract the pulse features by the methods of image analysis. The pulse features which are selected by the stepwise regression analysis are substituted into the three regression equations to calculate the blood pressure. The results are closed with the blood pressure which we measured, and the error is small.The research shows that blood pressure features can be extracted by the pulse image sensor. So, the research provides a new means and methods for the noninvasive continuous blood pressure measurement.