人眼前房三维重建与房水流场数值模拟  

3D model reconstruction and numerical simulation of fluid dynamics in anterior chamber

作　　者：郭竞敏 张虹[1] 王军明[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院眼科,湖北省武汉市430032

出　　处：《眼科新进展》2015年第4期346-350,共5页Recent Advances in Ophthalmology

摘　　要：目的重建人眼前房三维仿真模型,探究不同前房流场内房水流动特征及动力学机理。方法基于房水生理学相关理论及流体力学基本原理,在人眼前节解剖特征的基础上,对不同宽窄的前房(房角分别为54°、45°、35°、25°)进行三维重建。用有限体积分析方法对不同瞳孔直径(1.5 mm、3.0 mm、5.0 mm、8.0 mm)及体位(立位、仰卧及俯卧)的房水流动进行数值模拟。结果构建了人眼前节三维仿真模型,模拟结果显示不同宽窄前房、瞳孔直径以及体位下前房流场的流线、流速、温度和切应力分布特征:房水在前房受浮升驱动呈涡流样流动,立位呈现与前房形状一致的椭圆形涡系,卧位则呈现沿瞳孔轴向360°方向扩散的环形涡系;前房越宽、瞳孔越小、房水流速越大,量级为100×10-6 m·s-1且立位约为卧位的10倍;前房热传递方式与固体导热类似呈线性分布,房水流动对前房温度分布几乎没有影响;虹膜角膜切应力主要受房水流速影响,两者为非线性关系,需进一步考虑房水流线作用。结论该模型较真实反映了不同前房参数下房水流动特征,数值模拟结果从房水动力学角度为研究闭角型青光眼危险因素提供了数理依据。Objective To investigate characteristic and mechanism of fluid dynamics with consideration of various parametric effects by 3D models of ocular anterior chamber computational fluid dynamics simulation. Methods Based on mechanisms of aqueous physiology and fluid dynamics,3D models of anterior chamber（ chamber angles were 54°,45°,35°,25°,respectively）were reconstructed with the human anatomical parameters as a reference. Numerical simulation of the aqueous flow was performed by using the finite volume method in the course of parametric changes such as pupillary diameter（ pupillary diameters were 1. 5 mm,3. 0 mm,5. 0mm,8. 0 mm,respectively） and position（ standing,supine or prone position）. Results 3D finite volume models of anterior chamber were built. The streamline,velocity,temperature and shear stress distributions in the anterior chamber were obtained from the results of numerical simulation,with consideration of various chamber angles,pupils and positions. Different positions appeared to have influence on the aqueous vortex which was induced by buoyancy. The vortex went like ellipse along the anterior chamber in standing position,otherwise it spread from the pupillary axis as a circular in other positions. The wider anterior chamber and angle with smaller pupillary diameter drove the flow faster,the order of velocity magnitude was 100 × 10- 6 m·s- 1,the maximum flow velocity of standing position was 10 times faster than that of supine and prone positions. The temperature distribution was linear which was similar to the heat conduction in solids. In addition,shear stress of corneal and iris was mainly affected by the flow velocity. But the results of date analysis showed that the shear stress would not change linearly with the flow velocity,it was necessary to take the vortex effect into consideration. Conclusion It is comparatively true that the finite volume model simulates the real aqueous flow characteristic of different anterior chambers accurately. The results of numerical simulation are

关 键 词：前房重建 浮升力 计算流体力学 

分 类 号：R775[医药卫生—眼科]