眼眶内窥镜手术导航系统关键技术研究与开发

发布时间：2018-05-26 21:55

本文选题：内窥镜手术 + 手术导航　；参考：《上海交通大学》2011年硕士论文

【摘要】：眼眶手术是外科领域最复杂的手术之一，眼眶解剖结构复杂，内含眼球、视神经、血管和眼外肌等重要组织，手术危险性高，损伤后会造成不可挽回的后果；眼眶骨折复位、视功能重建要求精度高、难度大。因此，国际上眼眶外科领域的发展趋势是微创化和高精度。内窥镜技术可以使手术微创化，而基于图像引导的手术导航技术可以提高手术的精度，将内窥镜技术和手术导航技术结合起来可以提高眼眶手术的精确性、安全性和微创性，目前国内尚未将此二者结合起来应用于眼眶手术。本文针对传统眼眶内窥镜手术治疗中存在的局限性，研究了基于图像引导的手术导航技术以及相关的几何原理，在此基础上开发了眼眶内窥镜手术导航系统。具体研究内容包括： 1．医学图像处理与三维重建问题。在图像处理方面，通过对常用空间滤波方法和图像分割方法的比较，运用中值滤波法对含有噪声的CT图像进行去噪处理，由于在CT图像中骨组织与其他软组织的灰度值有较大的差异，将阀值分割法和区域生长法结合起来实现对头部CT图像的骨组织分割。在图像三维重建方面，运用Marching cubes三维重建算法实现了对颅骨CT图像的三维重建，并采用二次误差测度方法实现网格简化。 2．手术导航系统中坐标系转换问题。针对手术导航系统中患者坐标和手术器械方位与坐标在不同坐标系之间的转换问题，采用四元数法表示空间坐标系的方位信息，推导了空间坐标系旋转四元数的求解表达式和不同坐标系之间旋转合成的四元数表达式，运用四元数的球面线性插值原理实现手术器械在三维模型坐标系下方位变换的平滑过渡。 3．空间配准问题。根据选取配准标记点的不同方法，通过对手术导航系统中空间配准的主要方法进行比较，采用基于人体解剖标记点和特征曲面的非倾入式配准方法实现配准，，将配准过程分为基于特征点的初配准和基于特征曲面的精配准，减少了对患者的创伤，提高了配准精度和配准速度。 4．内窥镜手术导航系统集成问题。基于Directshow技术开发了内窥镜视频采集系统，实现了内窥镜手术导航系统的集成，并通过实验模型验证了本手术导航系统的配准精度与实时跟踪精度。
[Abstract]:Orbital surgery is one of the most complicated operations in the field of surgery. Orbital anatomy is complicated, including eyeball, optic nerve, blood vessel and extraocular muscle and other important tissues. The reconstruction of visual function requires high precision and difficulty. Therefore, the international development trend of orbital surgery is minimally invasive and high precision. The endoscopic technique can make the surgery minimally invasive, while the image-based navigation technology can improve the accuracy, safety and minimally invasive of the orbital surgery, and the combination of the endoscopic technique and the surgical navigation technology can improve the accuracy, safety and minimally invasive of the orbital surgery. At present, the combination of the two has not been used in orbital surgery. Aiming at the limitation of traditional orbital endoscopic surgery, this paper studies the technique of image guided surgery navigation and the related geometry principle, and develops the navigation system of orbital endoscope surgery. Specific studies include: 1. Medical image processing and 3D reconstruction. In the aspect of image processing, the median filtering method is used to de-noise the CT image with noise by comparing the common spatial filtering method and the image segmentation method. Because there is great difference between the gray value of bone tissue and other soft tissue in CT image, the threshold value segmentation method and the region growth method are combined to realize the bone tissue segmentation of head CT image. In the aspect of 3D image reconstruction, the three-dimensional reconstruction of skull CT image is realized by using Marching cubes 3D reconstruction algorithm, and the mesh simplification is realized by using quadratic error measure method. 2. Coordinate system transformation in surgical navigation system. In order to solve the problem of the transformation of patient coordinate and surgical instrument azimuth and coordinate in different coordinate systems in the surgical navigation system, the quaternion method is used to express the azimuth information of the spatial coordinate system. In this paper, the solution expression of the rotation quaternion in the space coordinate system and the expression of the rotation composition between the different coordinate systems are derived. The principle of spherical linear interpolation of quaternion is used to realize the smooth transition of the position transformation of surgical instruments under the three-dimensional model coordinate system. 3. Space registration problem. According to the different methods of selecting registration mark points, the main methods of space registration in surgical navigation system are compared, and the non-tilt registration method based on human anatomical marker points and characteristic surface is adopted to realize registration. The registration process is divided into initial registration based on feature points and fine registration based on feature surface, which reduces the trauma to patients and improves registration accuracy and registration speed. 4. Integration of Endoscopic surgery Navigation system. Based on Directshow technology, an endoscope video acquisition system is developed, and the integration of endoscopic surgery navigation system is realized. The registration accuracy and real-time tracking accuracy of the system are verified by the experimental model.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R779.6

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