Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India.
Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, India.
Comput Methods Biomech Biomed Engin. 2021 Oct;24(13):1473-1487. doi: 10.1080/10255842.2021.1893311. Epub 2021 May 8.
Differences in the dynamics and transport of blood make certain regions of the arterial network the preferred sites for initiation and formation of arterial diseases like stenosis and aneurysms. Understanding of such arterial diseases is directly linked to critical hemodynamic parameters such as the wall shear stress (WSS). The present work generalises the influence of WSS on the concentration of LDL that was observed in an earlier study. To this end, a wide variety of simplified flow domain, inspired by the near-wall regions of aneurysms and stenosis, are constructed and analyzed. The effects of pulsatile inflow condition, rheology of blood and curvature of the wall on the correlation between WSS and LDL concentration are investigated. It is demonstrated that the time-scale of variation of lumen-surface-concentration (LSC) of LDL is larger than a single cardiac cycle. As a consequence, the time-average values of WSS are sufficient to locate the regions of higher LSC. This idea is strengthened by making use of simplified flow domain that generates moving stagnation point. Further, it was observed that the rheology of the blood and curvature of the wall does not affect the observed correlation between the WSS and LDL concentration.
血液动力学和输运的差异使得动脉网络的某些区域成为动脉疾病（如狭窄和动脉瘤）起始和形成的首选部位。对这类动脉疾病的理解与壁面切应力（WSS）等关键血流动力学参数直接相关。本工作推广了早期研究中观察到的 WSS 对 LDL 浓度的影响。为此，构建并分析了多种受动脉瘤和狭窄近壁区域启发的简化流场。研究了脉动入口条件、血液流变学和壁面曲率对 WSS 与 LDL 浓度之间相关性的影响。结果表明，LDL 的腔面浓度（LSC）的变化时间尺度大于单个心动周期。因此，WSS 的时间平均值足以定位具有较高 LSC 的区域。通过使用产生移动驻点的简化流场，可以加强这一想法。此外，还观察到血液的流变学和壁面的曲率并不影响观察到的 WSS 与 LDL 浓度之间的相关性。
