The arteriovenous fistula (AVF), which is a vasculature created for end-stage renal disease patients who require haemodialysis, is susceptible to many vascular diseases. It is well known that disturbed hemodynamics is a factor in the initiation of vascular disease; however, only a limited number of experimental studies have been conducted to assess the flow behaviour within the AVF. The current study is an investigation of the complex three-dimensional flow within a physiological AVF geometry, using tomographic particle image velocimetry. To this end, a benchtop model of a patient-specific geometry was created by casting silicone around a soluble 3D print of the vessels. The patient-specific boundary conditions were reproduced by driving a refractive-index matched working fluid from a pulsatile pump, which was connected to the model via a tubing network inclusive of valves and compliance chambers. The seeded working fluid was illuminated with a 1 kHz double-pulsed laser, and four high-speed cameras placed at optimised locations were used to capture the particle images, with the volume reconstructions refined by a 3D internal mask created using morphological operations. The velocity magnitude contour plots of the resulting vector field revealed two zones of low velocity in the anastomosis, while locations of high turbulent kinetic energy are observed in the anastomosis and venous regions. These results suggested that the collision of the two opposing inlet flows and the curvature at the anastomosis cause disturbance in the flow that is carried downstream.

中文翻译：

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特定患者动静脉瘘中生理流动条件的断层扫描 PIV 分析

动静脉瘘 (AVF) 是为需要血液透析的终末期肾病患者创建的脉管系统，易患许多血管疾病。众所周知，血流动力学紊乱是引发血管疾病的一个因素。然而，仅进行了有限数量的实验研究来评估 AVF 内的流动行为。目前的研究是使用断层扫描粒子图像测速法对生理 AVF 几何结构内复杂的三维流动进行调查。为此，通过在血管的可溶性 3D 打印件周围铸造硅胶，创建了患者特定几何形状的台式模型。通过从脉动泵驱动折射率匹配的工作流体来再现患者特定的边界条件，它通过管道网络连接到模型，包括阀门和柔顺室。接种的工作流体用 1 kHz 双脉冲激光照射，四个高速摄像机放置在优化位置，用于捕获粒子图像，体积重建由使用形态学操作创建的 3D 内部掩模精制。所得矢量场的速度幅度等值线图显示吻合中的两个低速度区域，而在吻合和静脉区域中观察到高湍流动能的位置。这些结果表明，两个相对的入口流的碰撞和吻合处的曲率会导致下游流动的干扰。接种的工作流体用 1 kHz 双脉冲激光照射，四个高速摄像机放置在优化位置，用于捕获粒子图像，体积重建由使用形态学操作创建的 3D 内部掩模精制。所得矢量场的速度幅度等值线图显示吻合中的两个低速度区域，而在吻合和静脉区域中观察到高湍流动能的位置。这些结果表明，两个相对的入口流的碰撞和吻合处的曲率会导致下游流动的干扰。接种的工作流体用 1 kHz 双脉冲激光照射，四个高速摄像机放置在优化位置，用于捕获粒子图像，体积重建由使用形态学操作创建的 3D 内部掩模精制。所得矢量场的速度幅度等值线图显示吻合中的两个低速度区域，而在吻合和静脉区域中观察到高湍流动能的位置。这些结果表明，两个相对的入口流的碰撞和吻合处的曲率会导致下游流动的干扰。使用形态学操作创建的 3D 内部蒙版对体积重建进行了改进。所得矢量场的速度幅度等值线图显示吻合中的两个低速度区域，而在吻合和静脉区域中观察到高湍流动能的位置。这些结果表明，两个相对的入口流的碰撞和吻合处的曲率会导致下游流动的干扰。使用形态学操作创建的 3D 内部蒙版对体积重建进行了改进。所得矢量场的速度幅度等值线图显示吻合中的两个低速度区域，而在吻合和静脉区域中观察到高湍流动能的位置。这些结果表明，两个相对的入口流的碰撞和吻合处的曲率会导致下游流动的干扰。