利用非均匀格子Boltzmann方法研究支架对颅内动脉瘤血流动力学的影响

发布时间：2018-01-27 17:35

本文关键词： 颅内动脉瘤非均匀格子Boltzmann方法支架非均匀网格血流动力学模拟　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：颅内动脉瘤是危害人类身体健康的疾病之一,虽然目前还不清楚具体的致病原因,但血液动力学机制被认为是颅内动脉瘤形成、发展乃至破裂的主要因素,受到国内外学者的广泛关注。在临床治疗方面,植入支架的介入疗法取得了良好的治疗效果,相较于传统的手术方法具有风险小的特点。格子Boltzmann方法(LBM)是近年来迅速发展的一种流体系统建模和模拟的新方法,是介于流体的微观分子动力学模型和宏观连续模型之间的介观模型,兼具二者的优点。将LB方法与血流问题结合已被证实是一种有效的方法,但是对于支架具体形态、旋转、位置等特性没有深入的讨论,且对于支架的研究不够精准。非均匀格子Boltzmann方法是将格子Boltzmann方法与非均匀网格方法进行结合,同时可以准确捕捉变化剧烈区域的流场信息,因此可以兼顾计算精度和效率。首先本文对二维动脉瘤模型进行模拟探讨,在二维情形中侧重血流动力学机制方面的探讨。其中包括探讨不同旋转角度的支架的作用差异,利用三角形的支架进行研究;探讨不同截面支架的作用效果,分析了三角形、圆形、正方形、长方形、梯形的不同作用效果,并给出最优的支架截面;探讨了支架的放置位置,提出一种基于贪婪规则的支架放置方法。其次对三维情形下植入支架的颅内动脉瘤的血流情况进行模拟,主要侧重探讨具体动脉瘤模型下血流动力学信息的变化和支架的作用效果,展现动脉瘤内部的血液流动的真实情形。本文采用基于CUDA的图形处理单元GPU,有效结合格子Boltzmann的并行性,从而提高计算效率。本文的数值模拟结果在临床治疗上有一定的参考价值,为具体支架的设计提供指导。
[Abstract]:Intracranial aneurysm is one of the diseases harmful to human health. Although the specific causes of intracranial aneurysm are still unknown, the hemodynamic mechanism is considered to be the main factor for the formation, development and even rupture of intracranial aneurysm. The interventional therapy of stent implantation has achieved good results in clinical treatment. The lattice Boltzmann method is a new method for modeling and simulation of fluid systems which has been developed rapidly in recent years. It is a mesoscopic model between the micro molecular dynamics model of fluid and the macroscopic continuous model, which has the advantages of both. The combination of LB method and blood flow problem has been proved to be an effective method. However, the specific shape, rotation, position and other characteristics of the scaffold are not discussed in depth. The non-uniform lattice Boltzmann method combines the lattice Boltzmann method with the non-uniform grid method. At the same time, it can accurately capture the information of the fluid field in the highly changing region, so it can give consideration to the accuracy and efficiency of the calculation. Firstly, the two-dimensional aneurysm model is simulated and discussed in this paper. In the two-dimensional case, the hemodynamic mechanism is discussed, which includes the study of the different role of the stent with different rotation angles, and the use of triangular scaffold. The different effects of triangle, circle, square, rectangle and trapezoid are analyzed, and the optimum section of the bracket is given. In this paper, the placement of stents is discussed, and a method of stent placement based on greedy rule is proposed. Secondly, the blood flow of intracranial aneurysms implanted with stents is simulated. The changes of hemodynamic information and the effect of stents on the specific aneurysm models were mainly discussed. To show the true situation of blood flow inside the aneurysm, this paper uses GPU, a graphics processing unit based on CUDA, to effectively combine the parallelism of lattice Boltzmann. In order to improve the computational efficiency, the numerical simulation results in this paper have some reference value in clinical treatment, and provide guidance for the design of specific scaffolds.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O175

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