Shannon Alexander T, Mirbod Parisa
Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY, USA.
Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY, USA.
Microvasc Res. 2017 May;111:88-95. doi: 10.1016/j.mvr.2017.01.004. Epub 2017 Jan 19.
In this study, three-dimensional (3D) blood flow of the feto-placental vasculature system of the mouse placenta was investigated using computational fluid dynamics (CFD) methods and finite element analysis. Micro-computerized tomography (micro-CT) images were used to acquire the 3D geometry of the feto-placental vasculature system, and image-processing software has been used to calculate the 3D morphology of the placenta. The flow was analyzed numerically and compared to the experimental data received from the same model. The numerical and experimental results agree well. Experimentally measured time dependent blood velocity data, available in the literature, was used as the inlet boundary condition to represent the fetal blood pulsatile flow. Velocity profiles and pressure distributions are investigated during different phases of the unsteady flow. The results clearly illustrate the important role of the vasculature structure (e.g., diameter and curvature) in the fetal hemodynamics, which to our knowledge has not been examined previously. The data also show that, at each bifurcation, the blood flow velocity decreases significantly in the transition from the parent vessel (i.e., umbilical artery) to the daughter vessels because of the higher total cross-sectional area of the daughter vessels compared to the parent vessel. It can also be observed that pressure drop at the umbilical artery and pressure drop across the arterial trees obtained in this study agree well with the physiological data reported in the literature. Moreover, the velocity profiles after each bifurcation are symmetric. Finally, from the results no secondary flow has been observed in the vasculature system. This study provides a foundation in understanding and modeling the complex structure of the feto-placental vasculature system and serves as a first step towards developing new concepts for computational analysis of the feto-placental vasculature systems of both human and mouse to better understand how the placenta functions and how gas and nutrient exchange between the mother and fetus.
在本研究中，使用计算流体动力学（CFD）方法和有限元分析对小鼠胎盘的胎儿 - 胎盘血管系统的三维（3D）血流进行了研究。利用微型计算机断层扫描（micro-CT）图像获取胎儿 - 胎盘血管系统的3D几何形状，并使用图像处理软件计算胎盘的3D形态。对血流进行了数值分析，并与从同一模型获得的实验数据进行了比较。数值结果与实验结果吻合良好。将文献中可用的实验测量的随时间变化的血流速度数据用作入口边界条件，以表示胎儿血液的脉动流。研究了非定常流不同阶段的速度剖面和压力分布。结果清楚地说明了血管结构（例如直径和曲率）在胎儿血流动力学中的重要作用，据我们所知，此前尚未对此进行过研究。数据还表明，在每个分叉处，由于子血管的总横截面积比母血管大，从母血管（即脐动脉）到子血管的过渡过程中血流速度显著降低。还可以观察到，本研究中获得的脐动脉压降和整个动脉树的压降与文献报道的生理数据吻合良好。此外，每个分叉后的速度剖面是对称的。最后，从结果中未观察到血管系统中有二次流。本研究为理解和建模胎儿 - 胎盘血管系统的复杂结构提供了基础，并作为朝着开发用于计算分析人类和小鼠胎儿 - 胎盘血管系统的新概念迈出的第一步，以更好地了解胎盘的功能以及母体与胎儿之间的气体和营养物质交换情况。
