Study of Estimation Method for Unsteady Inflow Velocity in Two-Dimensional Ultrasonic-Measurement-Integrated Blood Flow Simulation
Study of Estimation Method for Unsteady Inflow Velocity in Two-Dimensional Ultrasonic-Measurement-Integrated Blood Flow Simulation
复制标题
二维超声测量积分血流模拟中非定常流速估计方法研究
DOI：
10.1109/tbme.2015.2461559
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发表时间：
2016
影响因子：
4.6
通讯作者：
and Nobuyuki Taniguchi
中科院分区：
文献类型：
--
作者：
Hiroko Kadowaki;Toshiyuki Hayase;Kenichi Funamoto;and Nobuyuki Taniguchi
血流动力学信息对于阐明循环系统疾病的机制和开发新的诊断方法至关重要。二维超声测量集成（2D-UMI）仿真通过将超声测量结果反馈到血流数值仿真中，能够正确再现血管内血流场和血流动力学。在这种方法中，给出正确的横截面平均流入速度（流入速度）作为边界条件至关重要。然而，现有的来流速度估计方法对各种目标流场的相对有效性和有效性尚未得到系统的研究。本研究的目的是系统地研究现有的方法，并建立一种方法，以准确地估计流入速度的各种血管的几何形状和流动条件的2D-UMI模拟。采用基于多普勒速度误差的评价函数对流入流速进行了二维UMI数值模拟实验，模拟了流入流速分布与血管轴对称和不对称的直血管中的血流模型。其结果是，它被澄清，一个显着的大的估计误差发生在不对称的流动，由于非反馈域附近的下游端的计算域。因此，提出了一种新的二维UMI模拟的来流速度估计方法，其中的反馈和评估域扩展到下游端。对健康血管和狭窄血管的二维UMI仿真实验证实了该方法的有效性。
Information on hemodynamics is essential for elucidation of mechanisms and development of novel diagnostic methods for circulatory diseases. Two-dimensional ultrasonic-measurement-integrated (2D-UMI) simulation can correctly reproduce an intravascular blood flow field and hemodynamics by feeding back an ultrasonic measurement to the numerical blood flow simulation. In this method, it is critically important to give the correct cross-sectional average inflow velocity (inflow velocity) as the boundary condition. However, systematic study has not been done on the relative validity and effectiveness of existing inflow velocity estimation methods for various target flow fields. The aim of this study was to examine the existing methods systematically and to establish a method to accurately estimate inflow velocities for various vessel geometries and flow conditions in 2D-UMI simulations. A numerical experiment was performed for 2D-UMI simulation of blood flow models in a straight vessel with inflow velocity profiles symmetric and asymmetric to the vessel axis using existing evaluation functions based on Doppler velocity error for the inflow velocity estimation. As a result, it was clarified that a significantly large estimation error occurs in the asymmetric flow due to a nonfeedback domain near the downstream end of the calculation domain. Hence, a new inflow velocity estimation method of 2D-UMI simulation is proposed in which the feedback and evaluation domains are extended to the downstream end. Further numerical experiments of 2D-UMI simulation for two realistic vessel geometries of a healthy blood vessel and a stenosed one confirmed the effectiveness of the proposed method.