Abstract：
The geometry of carotid bifurcation is a crucial contributing factor to the localization of atherosclerotic lesions. Currently, studies on carotid bifurcation geometry are limited to the region near to bifurcation. This study aimed to determine the influence of carotid bifurcation geometry on the blood flow using numerical simulations considering magnitude of haemodynamic parameters in the extended regions of carotid artery.
In the present study, haemodynamic analysis is carried out using the non-Newtonian viscosity model for patient-specific geometries consisting of both Left and Right carotid arteries. A 3D patient-specific geometric model is generated using MIMICS, and a numerical model is created using ANSYS.
The results obtained from patient-specific cases are compared. The influence of geometric features such as lumen diameter, bifurcation angle, and tortuosity on the haemodynamics parameters such as velocity, WSS, pressure, Oscillatory Shear Index (OSI), and Time-Averaged Wall Shear Stress (TAWSS) are compared.
The results demonstrate significant changes in the flow regime due to the geometric shape of the carotid artery. It is observed that the lower value of TAWSS occurs near the bifurcation region and carotid bulb region. In addition, the higher value of the (OSI) is observed in the Internal Carotid Artery (ICA) and the tortuous carotid artery region. However, it is also observed that apart from the bifurcation angle, other factors, such as tortuosity and area ratio, play a significant role in the flow dynamics of the carotid artery.
In the present study, haemodynamic analysis is carried out using the non-Newtonian viscosity model for patient-specific geometries consisting of both Left and Right carotid arteries. A 3D patient-specific geometric model is generated using MIMICS, and a numerical model is created using ANSYS.
The results obtained from patient-specific cases are compared. The influence of geometric features such as lumen diameter, bifurcation angle, and tortuosity on the haemodynamics parameters such as velocity, WSS, pressure, Oscillatory Shear Index (OSI), and Time-Averaged Wall Shear Stress (TAWSS) are compared.
The results demonstrate significant changes in the flow regime due to the geometric shape of the carotid artery. It is observed that the lower value of TAWSS occurs near the bifurcation region and carotid bulb region. In addition, the higher value of the (OSI) is observed in the Internal Carotid Artery (ICA) and the tortuous carotid artery region. However, it is also observed that apart from the bifurcation angle, other factors, such as tortuosity and area ratio, play a significant role in the flow dynamics of the carotid artery.
摘要：
目的：颈动脉分叉的几何形状是动脉粥样硬化病变定位的一个重要因素。目前,对颈动脉分叉几何结构的研究仅限于分叉附近的区域。本研究旨在使用考虑颈动脉扩展区域中血流动力学参数大小的数值模拟来确定颈动脉分叉几何形状对血流的影响。
方法：在本研究中，使用非牛顿粘度模型对由左颈动脉和右颈动脉组成的患者特异性几何结构进行血液动力学分析。使用MIMICS生成3D患者特定几何模型，并使用ANSYS创建数值模型。
结果：比较了从患者特定病例获得的结果。几何特征如管腔直径的影响，分叉角,以及血流动力学参数如速度的弯曲度，WSS,压力,振荡剪切指数(OSI)比较了时间平均墙剪应力(TAWSS)。
结论：结果表明，由于颈动脉的几何形状，血流状态发生了显着变化。观察到TAWSS的较低值发生在分叉区域和颈动脉球区附近。此外,在颈内动脉（ICA）和曲折的颈动脉区域中观察到较高的（OSI）值。然而,还观察到，除了分叉角之外，其他因素,如弯曲度和面积比，在颈动脉的血流动力学中起重要作用。
方法：在本研究中，使用非牛顿粘度模型对由左颈动脉和右颈动脉组成的患者特异性几何结构进行血液动力学分析。使用MIMICS生成3D患者特定几何模型，并使用ANSYS创建数值模型。
结果：比较了从患者特定病例获得的结果。几何特征如管腔直径的影响，分叉角,以及血流动力学参数如速度的弯曲度，WSS,压力,振荡剪切指数(OSI)比较了时间平均墙剪应力(TAWSS)。
结论：结果表明，由于颈动脉的几何形状，血流状态发生了显着变化。观察到TAWSS的较低值发生在分叉区域和颈动脉球区附近。此外,在颈内动脉（ICA）和曲折的颈动脉区域中观察到较高的（OSI）值。然而,还观察到，除了分叉角之外，其他因素,如弯曲度和面积比，在颈动脉的血流动力学中起重要作用。
