虚拟手术中自适应混合建模技术研究

发布时间：2018-04-05 14:23

本文选题：虚拟手术　切入点：无网格迦辽金　出处：《燕山大学》2015年硕士论文

【摘要】：虚拟现实技术是在计算机图形学的基础上发展起来的,虚拟现实技术与现代医学等技术的结合为虚拟手术的产生奠定了坚实的基础。虚拟现实技术在医学领域一个重要的应用就是虚拟手术仿真系统。虚拟手术仿真系统可为医生提供一个虚拟的手术环境,不但可以在视觉上为医生真实再现手术场景,还可以在触觉上构成还原。虚拟手术系统可用于手术之前制定计划、手术之中进行引导、医生的手术操作培训和患者的术后康复等,因此虚拟手术仿真系统的研究具有重要的意义。本文选取虚拟手术仿真系统中的软组织模型进行研究,以粘弹性力学为基础,以肝脏为例,对肝脏软组织进行建模、仿真、分析。本文的主要内容如下:首先,分析了虚拟手术的背景、意义、国内外的研究现状以及该技术以后的发展趋势,研究了虚拟手术仿真系统的重要组成部分和关键技术,分析了弹簧质点模型、有限元模型、边界元模型和无网格迦辽金模型等典型模型的优点以及存在的一些缺陷,研究了目前评价软组织形变模型优劣的一些重要指标。其次,以粘弹性力学为基础,针对目前软组织模型在真实性和实时性方面存在的缺陷,提出了耦合自适应无网格迦辽金与弹簧质点模型。该模型将软组织分为两个实体,即非手术区域和手术区域。在手术区域采用真实性高的自适应无网格法,在非手术区域采用实时性好的弹簧质点法,在两个区域之间建立过渡单元,实现手术区和非手术区两个实体区域的平滑过渡。为了进一步提高模型的实时性,提出了双自适应耦合无网格迦辽金与广义表面网格模型,该模型相对于耦合自适应无网格迦辽金与弹簧质点模型在非手术区域采用实时性更好的广义表面网格法。最后,本文对双自适应耦合无网格迦辽金与广义表面网格肝脏模型进行了仿真,并对仿真结果进行了相关分析。实验结果表明,文中提出的双自适应耦合无网格迦辽金与广义表面网格肝脏模型能够满足真实性和实时性的要求,验证了该模型的真实性和有效性。
[Abstract]:Virtual reality technology is developed on the basis of computer graphics. The combination of virtual reality technology and modern medicine has laid a solid foundation for the emergence of virtual surgery.Virtual surgery simulation system is an important application of virtual reality technology in medical field.Virtual surgery simulation system can provide a virtual operation environment for doctors. It can not only reproduce the operation scene for doctors visually, but also form a reduction in tactile sense.The virtual surgery system can be used to make plans before operation, guide during operation, train doctors' operation and recover patients after operation, so the research of virtual surgery simulation system is of great significance.The soft tissue model of virtual surgery simulation system is studied in this paper. Based on viscoelastic mechanics and taking liver as an example, the soft tissue of liver is modeled, simulated and analyzed.The main contents of this paper are as follows: firstly, the background and significance of virtual surgery, the research status at home and abroad and the development trend of this technology are analyzed, and the important components and key technologies of virtual surgery simulation system are studied.The advantages and disadvantages of typical models such as spring mass model, finite element model, boundary element model and meshless Galerkin model are analyzed, and some important indexes for evaluating soft tissue deformation model are studied.Secondly, based on viscoelastic mechanics, a coupled adaptive meshless Galerkin and spring mass model is proposed to solve the defects of the present soft tissue model in the aspects of authenticity and real-time.The model divides soft tissue into two entities: non-operative area and operative area.An adaptive meshless method with high authenticity is used in the surgical area and a spring mass method with good real-time performance is used in the non-operative area. The transition unit is established between the two regions to realize the smooth transition of the two entity regions in the surgical and non-operative areas.In order to further improve the real-time performance of the model, a double adaptive coupled meshless Galerkin model and a generalized surface mesh model are proposed.Compared with the coupled adaptive meshless Galerkin model and the spring particle model, this model adopts a better real-time generalized surface grid method in the non-operative region.Finally, the double adaptive coupled meshless Galerkin model and the generalized surface grid liver model are simulated, and the simulation results are analyzed.The experimental results show that the double adaptive coupled meshless Galerkin model and the generalized surface mesh liver model can meet the requirements of authenticity and real-time. The validity and authenticity of the proposed model are verified.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R616;TP391.9

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