血栓后髂主动脉的流固耦合模拟方法研究

A study on Iliac Aortic with Thrombosis Based on Fluid-Solid Interaction Numerical Simulation

目的:应用流固耦合方法模拟分析血栓后髂动脉内的血流及管壁的应力情况,验证本文所用的流固耦合方法的有效性,并为进一步研究心脑血管疾病的机理提供技术条件和研究方法,为临床诊疗应用提供一定指导。方法:基于逆向工程三维重构技术,应用医学图像后处理软件对通过临床采集的增强CT二维图像数据进行处理,获得了基于人体生理解剖结构的血栓后髂动脉的血流区域三维模型,并以此为基础统一构建0.3 mm厚度的弹性血管壁三维模型。应用通用有限元分析软件对血栓后髂动脉的血流及血管壁模型进行流固耦合模拟计算。结果:在对计算模型进行边界条件和初始条件有效设定的基础上,经过多次迭代耦合计算,获得研究对象在心动周期内不同时刻的血管壁形变、等效应力、壁面振荡切应力、血流速度矢量等相关血流动力学参数。结论:通过与他人研究结果的对比,验证了本文所用方法的有效性。并通过分析模拟结果,发现较大的等效应力、较小的壁面振荡切应力、缓慢的流速以及回流等复杂的血流及管壁应力情况容易使得血管狭窄处的内皮细胞受损严重、血小板加速聚集,进而加重血管栓塞,加剧血管的狭窄,为进一步研究心脑血管疾病的机理提供技术条件和研究方法,为临床诊疗应用提供一定指导。

Objective：Applying fluid-structure interaction method to simulate the interaction between the blood flow and vascu- lax wall in the iliac artery with thrombus, to verify the validity of fluid-structure interaction methods used in this paper, and though analyzing the simulation between blood flow and iliac artery wall with thrombus situations, provide a technical meth- ods for the further study of the mechanism of cardiovascular and cerebrova^cular diseases , and provide some guidance for clinical diagnosis and treatment. Methods： Applying medical image processing software to process the two-dimensional con- trast-enhanced CT image data that collected by clinical based on the reverse engineering method for three-dimensional recon- struction, obtained a three-dimensional model of blood flow region in the post-thrombotic physiological anatomy iliac artery, and then construct a three-dimensional model of the elastic vessel wall with unified thickness of 0.3 mm. Apply finite element analysis software to simulate the interaction between the blood flow and post-thrombotic vessel. Results： After several interac- tions coupling calculation on the basis of the effective boundary and initial conditions, obtained the hemodynamic parameters of vessel wall deformation, von raises ,oscillating wall shear stress, flow velocity vector and so on at different time during a cardiac cycle. Conclusions： By comparing the results with other researchers, demonstrate the effectiveness and validity of the methods used in this paper.By analyzing the simulation results, found that the larger von mises, smaller oscillating wall shear stress, slow flow rate, and blood reflux and so on easy to damage the endothelial cells on the stenosis vascular, accelerate platelets aggregation, thereby increased blood clots and vascular stenosis. This provide a technical method for the further study of the mechanism of cardiovascular and cerebrovascular diseases, and some guidance for the application of clinical diagnosis and treatment