Integrative Sciences and Engineering Programme (ISEP), National University of Singapore, Singapore, Singapore.
Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.
Int J Numer Method Biomed Eng. 2022 Jun;38(6):e3596. doi: 10.1002/cnm.3596. Epub 2022 Apr 7.
The computational cost of a three-dimensional (3D) fluid-structure interaction (FSI) simulation of a dissected aorta has prevented researchers from investigating the effect of a wide range of the heart rate on the hemodynamic quantities in the disease. We have presented a systematic procedure to develop a zero-dimensional (0D) model for a dissected aorta. A series of numerical experiments were used to calculate the values for the resistance, inertance, and compliance of each lumen with irregular geometries. Having validated the results from the 0D model against those from the 3D model for one heart rate, we used the 0D model to investigate the effect of the heart rate of 50-150 bpm on the flow rates and the pressures in an idealized geometry of an aortic dissection. The 0D model showed acceptable accuracy when compared with the 3D FSI simulation. For instance, at peak systole, 7.18% relative error in the flow rate in the true lumen was observed for 0D and 3D simulations. The flow rate in the true lumen showed a stronger dependency on the heart rate, that is, 300% for the true lumen and 1.5% for the false lumen. The pressure difference between the lumina increased non-monotonically as the heart beats faster. Because of its efficiency, the reported procedure can be used for uncertainty and sensitivity analysis of the hemodynamic quantities in a diseased aorta with complex geometries such as that of the aortic dissection.
三维（3D）血流动力学-结构相互作用（FSI）模拟对解剖主动脉的计算成本很高，这使得研究人员无法研究广泛的心率对疾病中血液动力学参数的影响。我们提出了一种系统的方法来开发解剖主动脉的零维（0D）模型。通过一系列数值实验，计算了具有不规则几何形状的每个腔的阻力、惯性和顺应性的值。在将 0D 模型的结果与特定心率的 3D 模型的结果进行验证后，我们使用 0D 模型来研究心率在 50-150bpm 范围内对理想主动脉夹层几何形状中的流量和压力的影响。与 3D FSI 模拟相比，0D 模型显示出可接受的准确性。例如，在收缩期峰值时，0D 和 3D 模拟中真腔中的流量相对误差为 7.18%。真腔中的流量对心率的依赖性更强，即真腔为 300%，假腔为 1.5%。随着心跳加快，腔之间的压差呈非单调增加。由于其效率，所报告的程序可用于具有复杂几何形状（如主动脉夹层）的病变主动脉中血液动力学参数的不确定性和敏感性分析。
