基于光电容积脉搏波的舒张期衰减时间常数的研究

发布时间：2018-05-31 06:58

本文选题：光电容积脉搏波 + 弹性腔模型　；参考：《浙江大学》2012年硕士论文

【摘要】：光电容积脉搏波(PPG)蕴含着丰富的心血管系统的生理病理信息。目前研究主要基于没有实际生理意义的幅度信息,却忽略了反映全身血管特征的形态学参数。衰减时间常数作为常用的形态学参数,可用来评估动脉粥样硬化等心血管疾病。由于现有衰减时间常数的估算方法或需要流量和(或)压力信息,或容易失效,并不完全适用于PPG。因此,本论文的研究目标是基于PPG的形态提出一种新的估算衰减时间常数的非迭代算法(Non-iterative shape method, NSM),主要工作如下： 1、通过仿真方法对比研究单腔及双腔模型的特点,得出双弹性腔模型复杂度高、实用性差的缺点,因此采用单弹性腔模型来描述PPG。 2、仿真验证衰减时间常数与PPG形态的相关性。分析比较了现有衰减时间常数估算方法,得出只有拟合法适用于PPG,由于容易迭代失败,鲁棒性不高,并不是最优算法。 3、提出NSM法。从PPG形态中提取出一个名为下降支面积差比(ADR)的参数,与衰减时间常数建立数学关系,借助分段线性插值估算衰减时间常数。 4、仿真和临床验证NSM法的准确及可行性。仿真结果的误差小于±3%。临床实验表明,与拟合法相比,NSM法效率提高近100倍,PPG曲线复原度几乎无差别。 NSM法基于PPG的形态,不需要对信号进行预校准或者归一化,优于现有其他算法。
[Abstract]:PPG contains abundant physiological and pathological information of cardiovascular system. At present, the research is based on the amplitude information without actual physiological meaning, but neglects the morphological parameters which reflect the characteristics of systemic blood vessels. As a common morphological parameter, attenuation time constant can be used to evaluate cardiovascular diseases such as atherosclerosis. The existing methods for estimating attenuation time constants require flow and / or pressure information, or are prone to failure, so they are not fully applicable to PPGs. Therefore, the purpose of this paper is to propose a new non-iterative shape method for estimating attenuation time constants based on the morphology of PPG. The main work is as follows: 1. The characteristics of single cavity model and double cavity model are compared by simulation method, and the shortcomings of high complexity and poor practicability of double elastic cavity model are obtained. Therefore, a single elastic cavity model is used to describe PPG. 2. The correlation between attenuation time constant and PPG morphology is verified by simulation. By analyzing and comparing the existing methods of estimating attenuation time constants, it is concluded that only the fitting method is suitable for PPG, because it is easy to fail in iteration, and its robustness is not high, so it is not the optimal algorithm. 3. NSM method is proposed. A parameter called descending branch area difference ratio (ADR) was extracted from the PPG form, and a mathematical relation was established with the attenuation time constant. The attenuation time constant was estimated by piecewise linear interpolation. 4. The accuracy and feasibility of NSM method were verified by simulation and clinic. The error of simulation results is less than 卤3. The clinical experiments show that the efficiency of NSM method is nearly 100 times higher than that of the fitting method, and there is almost no difference in the restoration of PPG curve. The NSM method is based on the shape of PPG and does not need to precalibrate or normalize the signal, so it is superior to other existing algorithms.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318

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