眼虚拟手术中膜组织的形变建模与仿真

发布时间：2018-04-11 23:41

本文选题：虚拟现实 + 质点-弹簧模型　；参考：《燕山大学》2012年硕士论文

【摘要】：随着现代科技的不断发展，计算机技术已在各个学科的研究中发挥着不可替代的作用。在医学领域，通过计算机和其它设备的结合来进行虚拟手术受到越来越多人们关注。与实际手术相比，虚拟手术不仅可降低手术成本，而且没有手术风险、在培养人才等方面也有着不可比拟的作用。虚拟手术中主要应用的技术有：计算机图像处理，人机交互，及传感器技术等。本文研究虚拟手术中膜组织形变这一课题，主要讨论了虚拟手术中形变建模及碰撞检测，并进行了模拟仿真。首先，虚拟手术的形变建模是研究虚拟手术的一个重要环节，本文主要对比了有限元法建模和质点-弹簧建模，并结合质点-弹簧模型的结构对组织模型进行了改进。添加了“虚拟管”，对改进后模型的受力和形变都做了具体分析，改进后模型使得在有附着的膜结构形变时有体积支撑力，模拟效果更加逼真。其次，在质点-弹簧模型中，对动力学方程的求解方法也做了详细的分析，通过对比几种求解方法的精度和所用时间，最后选用中点法对实验过程中形变进行求解。此外，针对碰撞检测算法中层次包围盒算法的缺点，，结合虚拟手术中检测对象的不同、提出了混合层次包围盒算法，既满足刚体的碰撞，也满足形变膜组织的碰撞，同时缩短了碰撞检测的时间，提高了实时性。结合建造模型给出了实验结果，验证了混合层次碰撞检测算法的有效性。最后对基于人体眼部膜组织手术，构建了含有体积支撑力的球形膜组织模型。在以VisualC++6.0和OpenGL函数库建构的开发环境下，借助(GHOST-SDK)软件开发包，利用触觉设备PHANTOM Omni进行了力反馈仿真实验。给出了仿真结果，并对实验结果进行了分析，验证了改进的模型和碰撞检测算法的可行性。
[Abstract]:With the continuous development of modern science and technology, computer technology has played an irreplaceable role in the research of various disciplines.In the field of medicine, virtual surgery through the combination of computer and other devices has attracted more and more attention.Compared with actual surgery, virtual surgery can not only reduce the cost of surgery, but also has no surgical risk, and plays an unparalleled role in training talents.The main techniques used in virtual surgery are: computer image processing, human-computer interaction, sensor technology and so on.In this paper, the deformation of membrane tissue in virtual surgery is studied. The deformation modeling and collision detection in virtual surgery are discussed and simulated.Firstly, deformation modeling of virtual surgery is an important part of virtual surgery research. In this paper, the finite element modeling and mass-spring modeling are compared, and the structure of mass-spring model is improved.With the addition of "virtual tube", the force and deformation of the improved model are analyzed concretely. The improved model makes the volume support force when the membrane structure is deformed with attachment, and the simulation effect is more realistic.Secondly, in the mass-spring model, the method of solving the dynamic equation is also analyzed in detail. By comparing the accuracy and time of several methods, the midpoint method is used to solve the deformation in the experiment.In addition, aiming at the disadvantage of hierarchical bounding box algorithm in collision detection algorithm, a hybrid hierarchical bounding box algorithm is proposed to meet the collision of rigid body and deformed membrane structure.At the same time, the time of collision detection is shortened and the real-time is improved.Experimental results are given based on the construction model, and the effectiveness of hybrid hierarchical collision detection algorithm is verified.Finally, a spherical membrane tissue model with volume supporting force was constructed based on human eye membrane tissue surgery.In the development environment constructed by VisualC 6.0 and OpenGL function library, the force feedback simulation experiment is carried out with the help of GHOST-SDK software development kit and the tactile device PHANTOM Omni.The simulation results are given and the experimental results are analyzed to verify the feasibility of the improved model and the collision detection algorithm.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R77;TP391.9

【参考文献】