Kolachalama Vijaya B, Bressloff Neil W, Nair Prasanth B, Shearman Clifford P
Biomedical Engineering Center, Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA 02139, USA.
IEEE Trans Biomed Eng. 2008 Mar;55(3):1176-84. doi: 10.1109/TBME.2007.912398.
A Bayesian surrogate modeling technique is proposed that may be able to predict an optimal bypass graft configuration for patients suffering with stenosis in the internal carotid artery (ICA). At the outset, this statistical technique is considered as a means for identifying key geometric parameters influencing haemodynamics in the human carotid bifurcation. This methodology uses a design of experiments (DoE) technique to generate candidate geometries for flow analysis. A pulsatile one dimensional Navier-Stokes solver incorporating fluid-wall interactions for a Newtonian fluid which predicts pressure and flow in the carotid bifurcation (comprising a stenosed segment in the internal carotid artery) is used for the numerical simulations. Two metrics, pressure variation factor (PVF) and maximum pressure (p()(m)) are employed to directly compare the global and local effects, respectively, of variations in the geometry. The values of PVF and p()(m) are then used to construct two Bayesian surrogate models. These models are statistically analyzed to visualize how each geometric parameter influences PVF and p(*)(m). Percentage of stenosis is found to influence these pressure based metrics more than any other geometric parameter. Later, we identify bypass grafts with optimal geometric and material properties which have low values of PVF on five test cases with 70%, 75%, 80%, 85%, and 90% stenosis in the ICA, respectively.5%, 80%, 85%, and 90% stenosis in the ICA, respectively.
提出了一种贝叶斯替代建模技术，该技术或许能够为患有颈内动脉（ICA）狭窄的患者预测最佳的搭桥配置。首先，这种统计技术被视为一种识别影响人体颈动脉分叉处血流动力学的关键几何参数的方法。该方法使用实验设计（DoE）技术生成用于流动分析的候选几何形状。一个包含牛顿流体的流体 - 壁相互作用的脉动一维纳维 - 斯托克斯求解器用于预测颈动脉分叉处（包括颈内动脉的狭窄段）的压力和流量，该求解器用于数值模拟。采用两个指标，压力变化因子（PVF）和最大压力（p()(m)）分别直接比较几何形状变化的全局和局部影响。然后使用PVF和p()(m)的值构建两个贝叶斯替代模型。对这些模型进行统计分析，以可视化每个几何参数如何影响PVF和p(*)(m)。发现狭窄百分比对这些基于压力的指标的影响比任何其他几何参数都大。之后，我们在五个测试案例中分别针对颈内动脉狭窄70%、75%、80%、85%和90%的情况，识别出具有低PVF值的具有最佳几何和材料特性的搭桥。
