【作者】 于健；

【导师】 潘振宽；

【作者基本信息】 青岛大学 ， 计算机软件与理论， 2006， 硕士

【摘要】 虚拟手术系统应该同时满足真实性和实时性的要求。弹簧质点模型可以满足实时性的要求,但它无法模拟人体软组织器官的粘弹性特征;传统的有限元模型虽然可以模拟人体的粘弹性特征,但其巨大的时间消耗使得这个方法无法给出实时的反馈。 混合弹性模型是一种基于有限元方法的优化模型,它由只支持形变的静态模型和支持切割与形变的动态模型组成,该模型克服了弹簧质点模型的缺陷;同时也满足了虚拟手术的实时性要求。实验证明混合弹性模型在虚拟手术的真实性和实时性之间达到了一个较好的折中效果,它可以实时的提供视觉反馈,并且为下一步在虚拟手术系统中加入力反馈器作好了准备。 本文主要从事了以下几个方面的研究工作: (1)混合模型的构建。 分别建立混合模型的静态模型和动态模型,通过两部分模型的边界点传递力与位移,建立独立格式的连接点文件。为了更好的对实验结果进行比较,本文采用不同的构建方法共建立了两组混合模型。 (2)编写仿真程序,本实验程序分为以下几个主要模块:基本变形类模块,主模拟程序模块,碰撞检测模块,图形绘制模块。 (3)对两组实验结果的各项数据进行分析比较,提出下一步进行改进的步骤与具体方法,并对虚拟手术技术的发展做出展望。更多还原

【Abstract】 The virtual surgery simulation system must fulfill the demands of the reality and the real-time. The spring-mass model meets the real-time requirement, but it can not reflect the elastic character. Although the traditional finite element method can solve the realistic problem very well, it can not output the real-time feedback due to its huge cost of computation.The hybrid elastic model is an optimization model basing on the finite element method and it is composed of a static part and a dynamic part. The former one just only supports the deformation and the latter one allows deformation and cutting. The model not only can overcome the demerit of spring-mass model, but can fulfill the real-time requirement. The result of experiment has shown a good compromise between the two demands. The model can output the real-time vision feedback and even can make it is possible to introduce the force feedback device into the virtual surgery simulation.This paper has mainly discussed the following contents:(1) Construct the hybrid model.Construct the static part and the dynamic part of the hybrid model separately. Force and displacement can be exchanged by the connecting vertices. Make out the connection vertices of the two groups of hybrid model and make the connection files separately. For the purpose of getting a better experimental result to be compared, we construct two groups of hybrid model using two different methods.(2)Edit the simulation program which can be divided into the following parts: the basic deformable module, the main simulation module, the collision module and the rendering module.(3)We analyze and compare the experimental data of the two groups of simulation in detail. We point out the steps to improve the experiment in future and make a prospect about the development of virtual surgery simulation.更多还原