Schrauwen Jelle T C, Koeze Dion J, Wentzel Jolanda J, van de Vosse Frans N, van der Steen Anton F W, Gijsen Frank J H
Department of Biomedical Engineering, Erasmus Medical Center, 's-Gravendijkwal 230, Faculty Building, Ee 2302, 3000 CA, Rotterdam, The Netherlands,
Ann Biomed Eng. 2015 Jan;43(1):59-67. doi: 10.1007/s10439-014-1090-9. Epub 2014 Aug 12.
Atherosclerotic disease progression in coronary arteries is influenced by wall shear stress. To compute patient-specific wall shear stress, computational fluid dynamics (CFD) is required. In this study we propose a method for computing the pressure-drop in regions proximal and distal to a plaque, which can serve as a boundary condition in CFD. As a first step towards exploring the proposed method we investigated ten straightened coronary arteries. First, the flow fields were calculated with CFD and velocity profiles were fitted on the results. Second, the Navier-Stokes equation was simplified and solved with the found velocity profiles to obtain a pressure-drop estimate (Δp (1)). Next, Δp (1) was compared to the pressure-drop from CFD (Δp CFD) as a validation step. Finally, the velocity profiles, and thus the pressure-drop were predicted based on geometry and flow, resulting in Δp geom. We found that Δp (1) adequately estimated Δp CFD with velocity profiles that have one free parameter β. This β was successfully related to geometry and flow, resulting in an excellent agreement between Δp CFD and Δp geom: 3.9 ± 4.9% difference at Re = 150. We showed that this method can quickly and accurately predict pressure-drop on the basis of geometry and flow in straightened coronary arteries that are mildly diseased.
冠状动脉粥样硬化疾病的进展受壁面剪应力影响。为计算患者特异性壁面剪应力，需要采用计算流体动力学（CFD）方法。在本研究中，我们提出了一种计算斑块近端和远端区域压降的方法，该方法可作为CFD中的边界条件。作为探索该方法的第一步，我们研究了10条拉直的冠状动脉。首先，用CFD计算流场并根据结果拟合速度剖面。其次，简化Navier-Stokes方程并用所得到的速度剖面求解以获得压降估计值（Δp(1)）。接下来，作为验证步骤，将Δp(1)与CFD得到的压降（ΔpCFD）进行比较。最后，根据几何形状和流量预测速度剖面，进而得到压降，即Δpgeom。我们发现，对于具有一个自由参数β的速度剖面，Δp(1)能充分估计ΔpCFD。该β与几何形状和流量成功关联，使得ΔpCFD与Δpgeom之间具有极好的一致性：在Re = 150时差异为3.9±4.9%。我们表明，该方法能够基于轻度病变的拉直冠状动脉的几何形状和流量快速准确地预测压降。
