The Research Of No Cuff Blood Pressure Measurement Based On Pulse Wave Parameter

Blood pressure is one of the important physiological parameters of human, which reflect the cardiovascular status of the human body. As the discontinuous blood pressure measurement technology has many shortcomings, the demand for continuous blood pressure measurement in clinical medicine has been strong. The pulse waveform contains many physiological and pathological information, this paper has researched a new blood pressure measurement base on the characteristic parameters of pulse wave which is without cuff. This measurement not only to achieve the continuous measurement of blood pressure, but also gets rid of the dependence of cuff, improve the measurement of comfort.In this paper, we use the fingertip pulse wave as the object of study, and research of the relationship between pulse wave characteristic parameters and blood pressure. Firstly, to design a portable pulse wave acquisition system, we use the msp430f6659 as the central control unit of the whole system and communicated with the highly integrated analog front end of the photoelectric volume pulse wave. The acquisition system has local display and multiple communication functions, which can transmit data under the different conditions and suitable for remote medical treatment. Secondly, remove the noises of pulse wave by wavelet transform using Sym8 wavelet. And use the wavelet transform to identify the feature points of pulse, which based on dynamic threshold identification to identify wavelet coefficients. This method reduces the computation time, and it also ensures the accuracy. At last, to analyze the correlation between characteristic parameters of pulse wave and blood pressure. And using the stepwise regression to establish the regression equation of blood pressure which realized the continuous ambulatory blood pressure monitoring. To compare with the measured values, the result show that the average error is less than 3mmHg, which is meeting the requirements of the association for the advancement of medical instrumentation(AAMI) blood pressure measurement standard.