导　　师： 王树国;付宜利

学科专业： 080202

授予学位： 硕士

作　　者： ;

机构地区： 哈尔滨工业大学

摘　　要： 借助于导管进入人体血管病变部位进行治疗的血管微创介入手术是现代医学治疗方式的一项革命性突破,它具有传统外科手术无法比拟的优点,即手术出血少,创伤小,愈合期短等。目前,临床中普遍采用X射线与造影剂获得的二维导航图像作为介入手术插管过程中导管的导向依据。由于其缺乏交互性及三维直观感,对医生的操作技术要求过高,错误和重复的操作使得导管不易导向的同时,还会进一步损伤血管。在前期工作基础上,本文改进了漫游导航路径规划算法和手术导航方法,增加了碰撞检测技术,并将这些关键的功能模块进行集成,完善了辅助主动导管定位与导向的三维可视化导航软件系统。 研究了三维物体中心线的提取方法,详细论述了基于距离变换方法和梯度场方法实现物体中心线提取的过程。针对前者提取出的中心线存在连通性较差的问题,在物体距离变换的基础上用梯度场方法使其得到成功的解决,并通过中心线提取实验进行了验证。在提取出的血管三维模型中心线上选择起点和终点,用简单高效且易于实现的Bezier曲线对其进行平滑生成漫游导航路径,然后沿平滑后的路径控制虚拟相机进行虚拟内窥漫游,做术前规划。 采用基于OBB层次包围盒的碰撞检测算法,研究了OBB层次包围盒的固有特性,通过构建OBB和OBB层次包围盒树、包围盒间以及基本几何元素间重叠测试等技术,实现血管微创介入手术图像引导导航过程中主动导管及血管三维模型间的碰撞检测。检测过程具有良好的实时性和精确性,不仅增强了手术三维虚拟环境的真实性和沉浸感,并且对主动导管导航有着极其重要的辅助作用。 利用电磁三维位姿跟踪系统对主动导管进行术中定位。基于最近点迭代算法,对实际的物理空间/(病人空间/)和三维图像空间进行坐标变换,实现� Minimally invasive vascular surgery, which cures with the access of a catheter to the vascular lesion area of human body, is a revolutionary breakthrough in modern medicinal treatment. It is superior to the traditional cardiac surgery——less bleeding and postoperative injury, shorter healing stage. In current clinical surgery, 2D navigation image obtained by X-ray and contrast medium is regarded as the guiding basis of the catheter during the catheterization. That, however lacks interaction as well as 3D visualization, demands too much of the operators’skill. The improper and repetitive actions may intensify the guiding difficulty of catheter, even arouse worse vascular trauma at the same time. Based on the preliminary work, this paper improved wandering navigation path planning algorithm and the way of surgical navigation, increased collision detection method, then integrated these key functional modules to achieved a better 3D visual navigation system which assists in positioning and guiding of the active-catheter. After the discussion of Centerline extraction methods in 3D objects ,this paper specifies in detail the realization of the Centerline extraction based on distance transform and gradient-vector field methods. The problem of bad connectivity of centerline extracted by distance transform method can be successfully solved through gradient field method; the results are verified by centerline-extracting experiment. Select the beginning and end point on centerline, smoothing it with easy-achieving Bezier curve to generate the navigation path, and then use virtual Camera to control virtual endoscopic wandering along the smoothed path, after that preoperative program can be made. The collision detection algorithm based on OBB hierarchical box is adopted in this paper. The collision detection between active-catheter and 3D vascular model in image-guided navigation of minimally invasive vascular surgery is realized, by means of researching on the inherent characteristic of OBB hierarchical box,

关 键 词： 微创介入手术 中心线提取 碰撞检测 手术导航

领　　域： [自动化与计算机技术] [自动化与计算机技术]