Numerical and experimental study of blood flow through a patient-specific arteriovenous fistula used for hemodialysis
Numerical and experimental study of blood flow through a patient-specific arteriovenous fistula used for hemodialysis
复制标题
DOI：
10.1016/j.medengphy.2009.10.013
复制
发表时间：
2010-03-01
影响因子：
2.2
通讯作者：
Legallais, Cecile
中科院分区：
文献类型：
--
作者：
Kharboutly, Zaher;Deplano, Valerie;Legallais, Cecile
动静脉瘘（AVF）与血流相关的病理需要有效的计算工具来确定局部速度和壁面剪应力，以克服临床诊断的局限性。为了说明这一问题，研究人员利用计算流体动力学（cfd）和粒子图像测速（PIV）对患者特异性AVF进行了重建。本研究的目的是通过比较数值和实验数据，验证从医学图像到AVF数值模拟的方法。两种数值网格的细化差为4倍。创建了相同体积的模具，并将其安装在具有相似边界条件的实验台上。在动脉入口处注射患者获得的DOO6Fppler血流波形。实验和数值速度矢量制图定性地产生了类似的流场。定量与点对点的方法彻底研究了速度分布使用两个结果之间的平均差异。以PIV为参考，最细网格生成的CFD结果中速度幅度差的平均百分比不超过10%。在特定区域，粗网格需要自适应网格划分，以提高与实验数据的拟合。为了提高宽直径处的速度精度和窄直径处的壁面剪应力，需要进行网格细化。如果这些标准得到适当的尊重，我们通过这个困难的例子展示了使用CFD来正确描述基于图像的重建血管的流动模式的有效性。(c) 2009年度。Elsevier Ltd.出版。版权所有。
Arteriovenous fistula (AVF) pathologies related to blood flow necessitate valid calculation tools for local velocity and wall shear stress determination to overcome the clinical diagnostic limits. To illustrate this issue, a reconstructed patient-specific AVF was investigated, using computational fluid dynamics (CFDs) and particle image velocimetry (PIV). The aim of this study was to validate the methodology from medical images to numerical simulations of an AVF by comparing numerical and experimental data. Two numerical grids were presented with a refinement difference of a factor of four. A mold of the same volume was created and mounted on an experimental bench with similar boundary conditions. The patient's acquired echo DOO6Fppler flow waveform was injected at the arterial inlet. Experimental and numerical velocity vector cartography qualitatively produced similar flow fields. Quantification with a point-to-point approach thoroughly investigated the velocity profiles using the mean difference between both results. The finest mesh generated CFD results with a mean percentage of the difference in velocity magnitude, taking the PIV as reference, did not exceed 10%. At specific zones, the coarse mesh required adaptive meshing to improve fitting with experimental data. Meshing refinement was necessary to improve velocity accuracy at wide diameters and wall shear stress at narrow diameters. Provided that these criteria were properly respected, we show through this difficult example the validity of using CFD to properly describe flow patterns in image-based reconstructed blood vessels. (C) 2009 IPEM. Published by Elsevier Ltd. All rights reserved.