基于CT成像的冠状动脉搭桥血管的流固耦合分析

    Fluid-structure Interaction Analysis of Coronary Artery Bypass Graft Based on the CT Images

    • 摘要: 针对冠状动脉旁路再狭窄重建个性化血管模型,通过计算流体力学方法研究血管几何模型和弹性血管壁对血流动力学特性变化导致的冠脉搭桥血管再狭窄的影响.根据冠状动脉搭桥手术患者的原始CT数据,导入到MIMICS软件中构造出冠状动脉移植血管的三维表面模型,并生成血管壁NURBS曲面模型,进而建立血管壁/血液耦合模型,采用有限元方法在ANSYS Mechanical和CFX两个模块的基础上,通过专用的流固耦合算法实现弹性血管壁和血液的双向耦合计算,在给定脉冲压条件下模拟出弹性管壁和刚性壁面的壁剪应力分布和变形情况,并且进行比较.研究结果表明:个性化模型的最大壁面剪应力和位移要高于CAD简化模型,而且2模型中最大位移发生的位置也完全不同;流固耦合模型的最大壁面剪应力和位移均低于刚性血管壁模型.计算结果可为临床上冠脉再狭窄的诊断提供更加合理的数据参考.

       

      Abstract: For the personalized reconstructed model of restenosis after coronary artery bypass graft,the influence of geometry model and elastic vessel wall on hemodynamic resulting in restenosis is studied by using computational fluid dynamics.Based on the original CT data of coronary artery bypass graft from patients,the surface model of coronary artery bypass graft is constructed and vessel wall is generated,and the surface model of coronary artery bypass graft is constructed and vessel wall is generated in MIMICS.The coupled model of vessel wall and blood established,fluid-structure interaction based on the two-way is carried out in ANSYS Mechanical and CFX modules by using the finite element method.The wall shear stress and deformation of elastic wall and rigid wall are compared with in a given pulse pressure condition.Results show that the maximum wall shear stress and displacement of the personalized model are higher than those of the simplified CAD model,and locations of maximum displacements in both models are absolutely different.The maximum wall shear stress and displacement are lower than those of the rigid model.Simulation results provide more realistic reference data for diagnosis of restenosis after coronary artery bypass graft.

       

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