Study On Continuous Blood Pressure Measurement Method Based On Pulse Wave Characteristics

As one of the important physiological parameters of human being, blood pressure can reflect the status of human cardiovascular function. It is also an important indicator of disease prevention and diagnosis clinically. Therefore, the measurement of blood pressure, especially continuous non-invasive ambulatory blood pressure monitoring, has a great significance in clinic. As the pulse wave signal contains diverse physiological and pathological information about cardiovascular system, the changes of waveform characteristics on pulse wave are important bases for evaluating the status of blood pressure and other physiological and pathological information in cardiovascular system.In this paper, the authors use the radial artery pulse wave in the wrist as the object of study, and pay more attention on the research of the relationship between the characteristic parameters of pulse wave and arterial blood pressure. Firstly, in order to collect the pulse wave signal conveniently, a pulse wave signal collecting system is designed based on STM32. Using this system, it’s convenient to realize the collection of pulse wave signal, preprocessing, A/D conversion, signal storage and display in real-time. Then, we did further study on the detecting method of features in pulse wave under Matlab on PC, accurately identify the feature point of pulse wave through wavelet transform algorithm, and get a better result. At last, this paper extracted the characteristic parameters of pulse wave, analyzed the correlation between characteristic parameters and blood pressure, established the regression equation and realized the continuous ambulatory blood pressure monitoring. And the measuring accuracy of this method is analyzed; the error between calculated blood pressure by using regression equation and actual measured blood pressure is compared. The experimental results show that the errors of two methods keep within3mmHg. The finding indicates that the proposed method of continuous blood pressure measurement based on the analysis of characteristics of pulse wave has high precision.