医学数据可视化及软组织建模
软件工程 黄鹏飞 指导教师 顾力栩
【摘要】 自百年前伦琴发现X 射线以来,医学图像可视化经历了革命性的发展。医学知识、物
理概念、数学方法和计算机科学理论有机地融合在医学图像处理之中。医学虚拟现实是计算机科学
家孜孜不倦的追求。近年来,人体器官软组织的三维建模更是计算机图形学的重要研究课题。而软
组织建模是实时手术虚拟和人机交互的基础。
本文提出并讨论了质点弹簧算法,它将形变物体表面建模成质点弹簧网络,其计算量小,但是
算法精度不高。然后介绍了中心线描绘算法,这种新型算法通过中心线信息对表面进行重绘,从而
模拟形变,常被用作图像的分割、配准。虽然它的实时性不是很理想,但是它重绘的思路在软组织
建模中颇有价值。于是,笔者结合了简化了的中心线描绘模型与质点弹簧模型,即在物体主要受力
形变区域采取质点弹簧模型,在其它区域采取中心线描绘模型。这样既保证了局部形变的实时性,
同时也保证了全局形变的逼真性。由于医学数据可视化是软组织三维建模的前提,本文还将介绍可
视化相关的三维重建、图像分割算法等问题。除了核心的三维建模部分,本文亦将介绍人机交互技
术、力反馈、碰撞检测、实时性与精确性等手术虚拟相关问题。
【关键词】 医学图像 网格 形变 质点弹簧 中心线描绘
【Abstract】 Since 100 years ago, when Roentgen discovered x-rays, medical image visualization has
revolutionarily developed. Medicine knowledge, physics concept, mathematics method and computer
science have interdisciplinarily worked together on the medical image processing. It is inherent for the
computer scientists to simulate the medical reality. In recent years, the 3D modeling of human organic
soft tissue has been an important research subject in computer graphics. And the soft tissue modeling is
the basis for the real-time surgery simulation and human computer interaction.
In this paper, we propose and discuss the mass-spring algorithm. It models the surface of deformable
object as the network of masses and springs. Its computational complexity is low but it is limited in
accuracy. And we propose a latest algorithm, medial representation. It redraws the surface based on the
centerline information to model the deformation and it is often used for image segemantation and
registration. Although its real-time property is not ideal enough, we can take advantage of its redrawing
strategy in soft tissue modeling. Therefore, we combine the mass-spring and medial representation
models so that we can achieve the real-time performance of local deformation and, at the same time, the
accuracy of entire deformation. Because medical data visualization is the precondition for soft tissue
modeling, we introduce the relating contents of 3D reconstruction and image segmentation. Besides 3D
modeling, which is the core part of surgery simulation, we also introduce the simulation’s relating issues
including human computer ineraction technique, force feeback, collision detection, accuracy and
real-time performance.
【Keywords】 Medical Image Mesh Deformation Mass-Spring Medial Representation
医学数据可视化及软组织建模
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目录
医学数据可视化及软组织建模 1
1 引言 3
1.1 研究背景····························································································· 3
1.2 研究目标····························································································· 3
1.3 内容组织····························································································· 3
2 医学数据可视化技术 3
2.1 概述····································································································· 3
2.2 医学数据三维重建·············································································· 3
2.2.1 医学图像数据格式······························································· 3
2.2.2 表面绘制技术······································································· 3
2.2.3 体绘制技术··········································································· 3
2.3 医学图像分割······················································································ 3
2.3.1 形态学方法··········································································· 3
2.3.2 快速步进法··········································································· 3
2.4 医学可视化平台开发实现·································································· 3
2.4.1 VTK 软件开发包···································································· 3
2.4.2 ITK 软件开发包···································································· 3
2.4.3 Atamai 手术导航软件开发包·············································· 3
2.4.4 基于Atamai 的医学可视化平台········································· 3
3 三维物体表面网格化技术 3
3.1 概述····································································································· 3
3.2 VTK 数据格式···················································································· 3
3.3 行进立方体算法·················································································· 3
3.4 气球算法····························································································· 3
4 人体软组织三维建模 3
4.1 概述····································································································· 3
4.2 质点弹簧算法······················································································ 3
4.2.1 质点弹簧拓扑结构······························································· 3
4.2.2 质点弹簧系统原理······························································· 3
4.2.3 表面模型··············································································· 3
4.2.4 体模型··················································································· 3
医学数据可视化及软组织建模
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4.3 中心线描绘算法·················································································· 3
4.3.1 中心线几何结构··································································· 3
4.3.2 根据中心线绘制表面··························································· 3
4.4 质点弹簧算法与中心线描绘算法的结合·········································· 3
4.5 三维建模应用程序开发实现······························································ 3
5 医学虚拟现实 3
5.1 概述····································································································· 3
5.2 交互作用技术······················································································ 3
5.2.1 三维图形坐标选取······························································· 3
5.2.2 碰撞检测··············································································· 3
5.2.3 力反馈··················································································· 3
5.3 实时性与真实性·················································································· 3
结论与展望 3
谢辞 3
主要参考文献 3
附录 3
医学数据可视化及软组织建模
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1 引言
1.1 研究背景
医学图像处理与分析技术涉及很多学科,包括计算机图像处理、计算机图形学、
模式识别、虚拟现实以及医学相关知识等。
关于医学图像的发展,是德国物理学家伦琴开创了人体图像的先河。1895 年11
月8 日,伦琴在研究时无意中发现了X 射线, |
|