中国针炙虚拟穴位人的三维重建研究

【作者】 林斌；

【导师】 鲍苏苏；

【作者基本信息】 华南师范大学 ， 计算机软件与理论， 2004， 硕士

【摘要】 数字化虚拟人体的研究是目前一个研究热点问题，虚拟人体是指在解剖、物理特征、生理生化机能方面全面系统地建立一个交互式数字化人体模型，为医学教育、临床诊断和治疗的研究提供精确的数学模型。本文所做的研究即是虚拟人体研究的一个分支，对虚拟人体在中医针炙穴位方面的交互式数字化进行一个初步探索性的工作。 本文一共分为六章。主要包括四个部分的内容：医学图像的预处理；三维表面模型的构建；模型的剖切；穴位的交互可视化。 第一章绪论部分对虚拟人体的模型构建技术，即医学三维重建技术进行了一个综述，其中包括的内容有对体数据的来源的说明，对医学图象的预处理，分割，常见的医学三维重建方法，模型网格简化方法进行了简单的描述。然后对中医针炙穴位理论研究的工作背景以及与本课题的关系进行了阐述。 第二章的内容是医学图像预处理及体数据分割，获取的图像或多或少有噪声的干扰，预处理的目的就是对其进行适当的处理，如滤波、平滑等，以实现噪声抑制。经过相应的格式转换、滤波处理或插值之后，将二维断层图像封装成一个三维体数据形式，便于存储和统一处理。对组织或器官的分割与提取是保证图重建模型准确表达相应组织器官的前提，本文采用的分割提取方法是：利用阈值进行组织分割；用数学形态学的操作进行区域修整；然后用种子填充法来提取所要分割的区域。 第三章主要对Marching Cubes(MC)表面重建算法进行描述，MC算法是基于规则体数据抽取等值面的经典算法，本文实现了这种等值面构建表面模型的算法，并对其算法的二义性进行了相应的处理；针对其重建速度较慢的问题，提出了体素间相关性处理的方法来加快重建速度；并对其生成的表面几何模型所包含三角面片数量巨大的问题，提出一种快速有效的三角形边收缩算法进行网格简化，提高了表面模型的绘制速度。 第四章对模型的剖切处理进行了阐述，为了观察三维体数据内部组织结构和空间位置，避免表面重建不能显示体数据内部信息问题，提出了一种类似光照投射法的算法，采用射影空间矩阵进行运算来获取切割面的图像信息。结合OpenGL中的纹理硬件加速显示，使得观察内部信息的观察变得快捷方便。 第五章对中医穴位的交互可视化进行描述，为了便于观察穴位的空间位置和其周围组织或器官信息，本文利用OpenGL中三维空间中的选取操作，提出了一种交互式的穴位定位方法。结合前几章的表面模型的构建、模型的剖切工作，比较好地显示了穴位空间位置信息和周围组织或器官的关系，为开展中医针炙穴位虚拟人体研究工作打下了一个基础。 第六章综述了本三维重建系统的开发。更多还原

【Abstract】 Research on digitized virtual human is a multi-disciplinary subject. Based on anatomy and physical and physiological-biochemistry character, digitized virtual human generally build a interactive human -like digitized model. This dissertation researches the application of digitized virtual human in acupuncture point and is a important branch of VHP(Virtual Human Project).In Chapter One, a survey is given on the model reconstruction from medical images, includes the origin and pre-processing of medical image, segmenting, general key techniques of 3D medical reconstruction, simplifying of meshes of the models. Then explain the background of the theory of Chinese medicine acupuncture.Chapter Two explores the pre-processing and segmenting of medical images. As the medical images are interfered by noises more or less, it is needed to restrain noises by filtering and smoothing. By changing the format of raw images and filtering or interpolating, the serial medical images are taken into a unite body data format file that is easy to manage and save. Segmenting and extracting tissues or organs from medical images are premises of 3D reconstruction models accurately. The methods of segmenting and extracting in this paper are described as follows: using threshold to segment the tissues; math-morphological methods to correct the region of tissues; using seed filling means to extracting the tissues or organs.In Chapter Three, MC(marching cubes) algorithm that is one of surface reconstruction methods is discussed, MC algorithm is a classical algorithm to extract iso-surface from regular volume data. MC algorithm in this paper has been implemented to extract iso-surface. The ambiguity in this algorithm is detected and eliminated. To improve the slow speed in reconstruction, a method to deal with the relativities is developed. Because 3D surface model contains huge number of triangles, a mesh simplification algorithm based on triangle edges shrinkages is presented in this paper to speed up the rendering in real time.In Chapter Four, the cutting of reconstructed 3D models is explored. In order to observe expediently the size and interspaces structure of inner tissues and avoid the discommodiousness of surface reconstruction, a simple cutting methods based on ray-casting algorithm is presented to get the inner images information. Combining the texture rendering of OpenGL with the display of cutting surface of 3D models, it is easy to observe the inner tissues or organs images information.In Chapter Five , we had studied the interactive visualization of acupuncture point of reconstructed 3D models. A interactive point orientation methods from the select operation of OpenGL is presented in this dissertation. With above iso-surface reconstruction and the cutting of reconstructed 3D models, it is convenient to observed the inner tissues or organs images information around some point, and at the same time a basic work is given to the farther virtual acupuncture human.In Chapter Six, four parts are described, they are pre-processing; 3D surface model reconstruction, cutting of 3D model and interactive visualization of acupuncture point.更多还原