用晶格Boltzmann方法研究青光眼流体力学

Glaucoma is one of the common diseases that cause serious harm to human health. Fluid mechanics plays a central role in generating, developing and blinding of glaucoma, and a lot of researches have been done on the fluid mechanics of glaucoma. However, up to now, there are still some fundamental problems have not been resolved, such as (1) The exact locations of the increased resistance for outflow of aqueous humor(AH) in open- angle glaucoma and the causes for the change in resistance are not understood; (2) The mechanisms underlying iris physically blocking the outflow of AH in closed-angle glaucoma have not been fully resolved; (3) The mechanism of the death of retinal ganglion cells in glaucoma has not been conclusively proven. Most of the previous studies on the fluid mechanics of glaucoma have been done with conventional numerical methods, and it may be a promising solution for doing those with a mesoscopic numerical method instead. In this project, a lattice Boltzmann model for studying fluid mechanics of glaucoma will be developed, based on the medical imaging data. By using of the high-performance parallel technologies, the dynamics of AH is simulated systematically, and the mechanisms of generating and developing of glaucoma are investigated. By simulating the flow of axoplasm in axon, the mechanism of the death of retinal ganglion cells in glaucoma is researched. Simulating the convection, diffusion and metabolic-consumption of drug in the whole therapeutic procedure, we may obtain the optimal schema of drug administration for improving the transportation efficiencies and therapeutic effects of the drug.

青光眼是一种严重危害人类身心健康的常见疾病。流体力学在青光眼发病、发展和致盲过程中扮演着中心角色，人们围绕青光眼流体力学开展了一系列的研究。然而，迄今为止，青光眼流体力学仍有许多挑战性的问题尚未解决，如：开角型青光眼房水出流阻力增加的准确部位和原因尚无定论；闭角型青光眼虹膜形变阻挡房水出流的基本原理尚不清晰；青光眼导致视网膜神经节细胞死亡的机制有待最终证明等等。已有的研究主要采用基于连续介质假设的传统数值方法，采用介观的数值方法研究是一种有希望的新思路。本项目拟基于医学影像数据发展介观晶格Boltzmann模型，借助高性能并行计算，对房水动力学进行系统模拟，探索青光眼的发病机制和发展过程；对轴浆在视神经轴突中的流动进行模拟，研究视网膜神经节细胞死亡的机制；对治疗全过程药物的对流、扩散和代谢消耗进行模拟，寻求提高药物输运效率和疗效的用药模式。

青光眼是一种严重危害人类身心健康的常见疾病。流体力学在青光眼发病、发展和致盲过程中扮演着中心角色，人们围绕青光眼流体力学开展了一系列的研究。然而，迄今为止青光眼流体力学仍有许多挑战性的问题尚未解决。已有的研究主要采用基于连续介质假设的传统数值方法，本项基于人眼的解剖结构数据提出了一种耦合热对流与扩散以及达西渗流的不可压缩的人眼房水动力学晶格Boltzmann模型。模拟结果与临床实验及已发表文献中的结果一致，显示该模型具有稳定性、收敛性和鲁棒性。然后使用数字图像处理技术对人眼OCT医学图像进行处理，提取个性化的人眼几何模型，构建基于人眼OCT医学图像的个性化房水动力学晶格Boltzmann模型。.常用的多相流晶格Boltzmann模型主要存在虚速度太大和模型不满足热力学一致性或伽利略不变性等问题。为了研究表面润湿性对房水流动的影响，我们从热力学自由能理论出发，提出了基于热力学的多相流模型，同时满足伽利略不变性和热力学一致性。然后采用化学势取代压力张量驱动相变过程，提高了计算效率，并能够合理的表达表面润湿性。为了提高数值模拟的密度比，采用高阶差分对化学势模型和伪势多相流模型做了改进，实现了超大密度比的模拟计算。在上述模型基础上，提出了精确的接触角介观测量方法，对动态接触角迟滞、液滴撞击液膜、气泡上升、液滴合并弹跳等问题进行了研究。并探索调节喷头的表面润湿性和添加表面活性剂，改进喷墨打印中墨滴的生成质量和飞行速度。基于这些研究，应邀发表了综述文章，介绍了晶格Boltzmann方法研究多相流的主流模型。.基于课题组对水力计算方法的研究，为进一步探索青光眼治疗药物颗粒的输运过程，深入对比研究了圆形、椭圆和方形颗粒的跨流层惯性迁移和平衡现象，分析了非圆颗粒在迁移过程中的周期性波动和非匀速旋转。应邀发表综述文章，全面介绍晶格Boltzmann方法研究流固耦合问题的进展。