Development of fluid-structure interaction simulator and its evaluation by in vitro measurement

流固耦合模拟器的研制及其体外测量评价

基本信息

批准号：
17360076
负责人：
OSHIMA Marie
金额：
$ 9.54万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

项目摘要

We developed an integrated cardiovascular system simulator and conducted image-based modeling and Fluid-Structure Interaction (FSI) Finite Element analysis (FEA) of human middle cerebral arterial aneurysm (MCAA). The computational model of MCAA is constructed from CT images.1)Development of cardiovascular system simulatorThe fluid is assumed to be laminar, Newtonian, viscous, and incompressible to represent blood. The arterial wall is assumed to be hyperelastic, isotropic, incompressible, and homogeneous. Fluid-structure coupling is performed by strong coupling method.The simulation result suggests that the hydrodynamic force of blood flow on aneurysm wall is not small and FSI analysis should be conducted for accurate analysis of cerebral aneurysm.We also structured peripheral vessel network based on anatomical knowledge, and applied the boundary condition taking account of the effects of peripheral vessel network to 3D hemodynamic simulation. 1D analysis of the peripheral vessels is a … More pplied as the boundary condition for 3D analysis, and 0D model as that for 1D analysis. For 0D model, structured tree impedance model is employed. The peripheral resistance, compliance, and impedance of vessel are treated by 1D analysis and 0D model.As a result, the present method shows a significant difference in flow rate of each artery and improvement in flow distribution and direction. Particularly, for the case with occlusion, collateral flow in the arterial circle of Willis is observed.2)Experiment using in vitro model with realistic vessel geometryWe made the in vitro model using rapid prototyping system and lost model technique. The model has realistic vessel geometry with cerebral aneurysm at bifurcation area. The measurement of flow structure in the aneurysm was conducted under the steady inflow conditions. The streamline is calculated form velocity data, and the flow structure along the aneurysm wall was observed. As the result of calculating the WSS (wall shear stress) using velocity data and geometry data, high WSS area was observed in the aneurysm.3) Comparison between numerical analysis and experimental resultWe compared experimental result to numerical analysis using the vessel geometry of in vitro model at same conditions. The velocity distribution and streamline pattern were similar, but high WSS was appeared at different area. Less

我们开发了一种集成心血管系统模拟器，并对人类大脑中动脉瘤 (MCAA) 进行了基于图像的建模和流固耦合 (FSI) 有限元分析 (FEA)。MCAA 的计算模型是根据 CT 图像构建的。1)心血管系统模拟器的开发假设流体是层流、牛顿、粘性且不可压缩的，以代表血液。假设动脉壁是超弹性的，采用强耦合方法进行各向同性、不可压缩、均匀的流固耦合。模拟结果表明，血流对动脉瘤壁的流体动力不小，需要进行FSI分析才能准确分析脑动脉瘤。基于解剖学知识构建外周血管网络，并将考虑外周血管网络影响的边界条件应用于外周血管的 3D 血流动力学模拟。 3D 分析和 0D 模型的边界条件与 1D 分析一样，采用结构化树阻抗模型，通过 1D 分析和 0D 模型处理血管的外围阻力、顺应性和阻抗。本方法显示出各动脉的流速存在显着差异，并且血流分布和方向有所改善，特别是对于闭塞的情况，观察到Willis动脉环中的侧支血流。2)实验。使用具有真实血管几何形状的体外模型我们使用快速原型系统和丢失模型技术制作了体外模型，该模型具有分叉区域脑动脉瘤的真实血管几何形状，在稳定流入条件下进行了动脉瘤中的流动结构的测量。根据速度数据计算流线，并观察沿动脉瘤壁的流动结构作为使用速度数据和几何数据计算WSS（壁剪切应力）的结果，在动脉瘤中观察到高WSS区域。 3）数值分析与实验结果的比较我们将实验结果与相同条件下体外模型的血管几何形状的数值分析进行了比较，速度分布和流线模式相似，但在不同区域出现了较高的WSS。