【摘要】 目的 构建包含静脉窦以及不包含静脉窦的两种不同结构的静脉模型，利用流固耦合仿真研究静脉窦结构对于下肢静脉系统血液流动的影响，分析静脉窦结构在静脉瓣开闭过程中的作用。方法 基于超声图像和动物解剖图像，使用建模软件建立两种不同结构的静脉系统三维几何模型，通过浸没边界法完成静脉瓣膜的流固耦合仿真，以获取瓣膜形态变化和流线分布、壁面剪切力分布、Q准则强度分布等血流动力学参数。结果 带窦模型的瓣膜几何开口面积大于无窦模型。血液流线的分布证明了窦区涡流与血管内螺旋流的存在。同端的静脉瓣对上呈现不对称的壁面剪切力分布，带窦模型静脉瓣背面的高壁面剪切力区域和远、近心端瓣膜间的Q准则强度均小于无窦模型。结论 静脉窦结构有助于静脉瓣膜的打开，对螺旋流动有一定的削弱作用，但螺旋流动模式有利于静脉窦区涡流的产生。静脉窦对静脉系统中的血流动力学有着重要影响，在静脉瓣的研究中应将静脉窦结构作为不可或缺的部分。更多还原

【Abstract】 Objective Two different venous models, one with and one without a venous sinus, each containing two pairs of adjacent orthogonal venous valves, were constructed. Using fluid-structure interaction(FSI) simulations, the influence of the venous sinus structure on blood flow in the lower limb venous system was studied, and the role of the venous sinus structure in the process of venous valve opening and closing was analyzed. Methods Based on ultrasound images and anatomical images of animals, two distinct three-dimensional(3D) geometric models of the venous system were constructed using modeling software. Using the immersed boundary method, FSI simulations of venous valves were performed to obtain hemodynamic parameters, such as changes in valve morphology, flow streamline distribution, wall shear stress(WSS) distribution, and Q-criterion intensity distribution. Results The geometric opening area of the valve in the model with sinuses was larger than that in the model without sinuses. The distribution of blood streamlines demonstrated the existence of vortices in the sinus region and helical flow within the vessel. The same venous valve pair exhibited an asymmetric distribution of WSS, with the region of high WSS behind the venous valve and the Q-criterion intensity between the far and near end valves being smaller in the sinus model compared to the non-sinus model. Conclusions The blood flow between two adjacent pairs of orthogonal venous valves exhibits a helical flow characteristics. The venous sinus structure facilitates the opening of the venous valve and the generation of vortices in the sinus region. However, the venous sinus structure may somewhat weaken the helical flow produced by the orthogonal venous valves. The venous sinus has a critical influence on the hemodynamics of the venous system, and in the study of venous valves, the venous sinus structure should be considered as an indispensable component.更多还原