脉搏波波速法无创血压测量中多模量血压计算模型研究

针对脉搏波波速法无创血压测量中血压计算模型建模困难和模型计算精度较低的问题,结合T_PTT、ln(T_PTT)及(1/T_PTT)²等模量建立多模量血压计算模型。首先,利用99名随机测试者的实验数据确定多模量模型参数,并基于实验数据计算各模型性能评价指标,其中多模量血压计算模型拟合相关系数最大,为0.891,误差方差最小,仅为6.1,实验表明,多模量血压计算模型具有更好的拟合效果和更低的计算误差。然后,利用医用水银血压计和自主设计的多模量血压测量系统两种方法采集另外36名随机测试者的收缩压和舒张压数据,并计算两种方法采集数据间的相关参数,其中收缩压差值的绝对值d<6 mmHg,差值均值E_d=0.55 mmHg,差值的标准差δ_d=2.98 mmHg;舒张压差值的绝对值d<6 mmHg,差值均值E_d=0.57 mmHg,差值的标准差δ_d=3.42 mmHg,完全符合美国医疗仪器促进协会SP10-199中对电子血压计测量差值＜8 mmHg的要求。最后,采用Bland-Altman差值法,对两种方法测量数据一致性进行检验,发现舒张压与收缩压的95 %一致性界限分别为(-5.3,6.4)和(7.2,-6.2),完全在临床血压测量可接受范围之内,较好地证明多模量血压计算模型用于无创血压测量的有效性。研究结果表明,多模量血压计算模型可以应用于脉搏波波速法无创血压测量。

Study on Multi-Mode Calculation Model in Non-Invasive Blood Pressure Measurement by Pulse Wave Velocity Method

Aiming to solve the problem of modeling difficulties and low calculating accuracy in the process of blood pressure measurement by pulse wave velocity method, a new multi modulus model of blood pressure calculation was built up with combination of multiple modulus T_PTT, ln(T_PTT) and (1/T_PTT)². Firstly, the parameters for the model were determined based on experimental data drawn from measurement carried out to 99 random voluntary subjects while performance evaluation indexes of each model were calculated simultaneously. It was found that the fitting correlation coefficient of the modulus model, equal to 0.891, was larger than that of any other model with the least error variance of the modulus model, equal to 6.1, smaller than that of any other model, which showed that the multi modulus model possessed better fitting effect and lower calculation error compared with single modulus models. Then, another 36 subjects' SBP and DBP data were collected by using mercury blood meter and the self-designed multi modulus blood pressure system separately, and the relevant parameters between the two methods were calculated. For SBP, d<6 mmHg, E_d=0.55 mm Hg and δ_d=2.98 mmHg, while for DBP, d<6 mmHg, E_d=0.57 mmHg and δ_d=3.42 mmHg, which could meet the requirements included in AAMI SP10|199. At last, the Bland-Altman difference method was applied to test the consistency of data between the two methods. A conclusion was drawn that 95% consistency limits of DBP and SBP were (-5.3, 6.4) and(7.2, -6.2) respectively, which satisfied the clinical demand and provided an evidence to the effectiveness of application of multi modulus model of blood pressure calculation in noninvasive blood pressure measurement. The research result proves that it is possible for multi modulus model of blood pressure calculation to be applied to noninvasive blood pressure measurement by pulse wave velocity method.