基于三次B样条曲线拟合的血压检测算法设计

Design of blood pressure detection algorithm based on cubic B-spline curve fitting

针对基于示波法的电子血压计采用幅度系数法作为血压判定算法存在的个体适应性差的缺点,文中提出一种结合幅度系数法和波形特征法对脉搏波采用三次B样条曲线拟合的血压检测算法,即在较宽松的包络线幅度范围内寻找收缩压和舒张压的特征点。针对脉搏波波形起伏变化大的特点,提出动态差分阈值法来定位脉搏波峰值点。选用STM32F103RCT6单片机作为主控芯片对信号进行采集和处理。实验测试结果表明,文中算法与标准水银血压计相比,误差均值都在5 mmHg内,符合ANSI/AAMI标准。说明文中算法能够提高特征点的准确率,提升血压检测的准确性和自适应性,可作为血压判定的依据。

As the blood pressure determination method, the amplitude coefficient method used in the electronic sphygmomanometer based on oscillography has poor individual adaptability,a blood pressure detection algorithm combining amplitude coefficient method and waveform feature method is proposed,in which cubic B-spline curve fitting is adopted for pulse wave,and the characteristic points of systolic and diastolic blood pressures can be searched in a relatively loose envelope range. As the waveform of pulse wave has the characteristics of great fluctuation,a dynamic differential threshold method is proposed to locate the peak point of pulse wave. The STM32F103RCT6 SCM is used as main control chip to collect and process the signal. The experimental testing results show that in comparison with the standard mercury sphygmomanometer,the error mean of the proposed algorithm is within 5 mmHg,which is in line with ANSI/AAMI standard. It can be seen that the proposed algorithm can improve the extraction accuracy of the feature points,and the accuracy and self-adaptability of blood pressure detection,which can be used as the basis for blood pressure determination.