【作者】 李昭；

【导师】 张天序；

【作者基本信息】 华中科技大学 ， 模式识别与智能系统， 2007， 硕士

【摘要】 心脏是人体循环系统的动力源,是人体中最重要的器官之一。它是集电生理学、动力学、血液流体力学以及神经、生化控制等于一身的极其复杂的综合系统。建模是研究复杂生物学问题的有效手段,利用计算机强大的计算能力和图形处理显示能力,建立心脏的三维模型并最终使其可视化是深入研究心脏的有效途径。模型不仅要从形态上仿真心脏,而且应能模拟真实心脏的运动过程,为研究动态心脏提供模型基础。本文主要建立了心脏的三维静态模型及四维动态模型,并设计显示界面对其进行显示和操作。所建心脏模型一方面根据冠状动脉依附在心脏表面的特性,可以对冠状动脉建模进行约束和指导,建立冠状动脉血管的静态及动态模型;另一方面经过X射线投影,得到二维图像可用于冠状动脉衰减投影图像的分析。本文通过构造心脏的心包和腔室的三维曲面的方法来进行静态心脏建模。在对人体心脏的解剖切片进行手工分割提取心包和各腔室的轮廓并用高斯滤波器对其进行平滑后,使用均匀取样的方法对轮廓进行取样,得到的样点作为心包和腔室的拟合点。在曲面拟合方面本文使用的是一种非均匀有理B样条(NURBS)曲面拟合法,这种方法在曲面拟合上具有准确和控制自由度高的优点。心脏静态模型是动态模型建立的基础,通过构造并连接一系列的由静态的心脏模型构成的时间帧来建立动态的心脏模型。根据心脏生理学特性,将一个心脏周期分成七个时期,并假定每一个时期内的心脏为线性运动,根据心脏运动的定量描述构造出7个时间帧并将其连接起来。显示方面使用的是显示工具VTK(Visual Toolkit),它不光可以对建立好的静态和动态模型进行显示,还可以对它们进行操作,增加了观察的灵活性。显示结果表明静态模型形态上比较接近真实心脏,动态模型也能很好的体现心脏的运动规律。更多还原

【Abstract】 The heart, which is the power source of human circulatory system, is one of the most important organs of human bodies. It is such a complex integrated system that includes Physiology, Dynamics, Blood Hydrodynamics and neurological, biochemical control. Modeling is an efficient tool to analyze the complex problems of biology.In this paper, we build 3D static and 4D dynamic models of heart and design visual interface to observe and operate it. The heart models are used on one hand to restrict and instruct coronary artery modeling as a result of coronary artery above the heart interface, the other hand to get 2D images through X-Ray for analyzing angiogram image of coronary artery.In this paper, constructing 3D surfaces of pericardium and antrum is used to model 3D static heart. First we manually segment the slice ups of human heart to get profiles and smooth them by Gaussian filters. Then the uniform sampling algorithm is used to sample points from the profiles. After it, a 3D surface model is constructed from the sampled points applying a surface fitting algorithm. Nonuniform Rational B-Spline (NURBS)is represented to fit surface as its accuracy and manageability. Static heart is the foundation of dynamic heart. After constructing and connecting a series of time frames of static heart models, a dynamic heart model has been constructed. Cardiac circle is divided into 7 time segments based on physiology knowledge and the movement between each segment is supposed linear. In accordance of description of heart movement, 7 time frames are constructed and connected together to form the dynamic heart model.Visual Toolkit (VTK)is used as the visualization tool. It can not only show the static and dynamic heart models, but also handle them freely.The result indicates the static heart model constructed looks like real heart and the dynamic heart model built expresses heart movement well.更多还原