中文摘要：

针对计算机辅助脊椎手术三维导航技术中术前CT图像与术中实际对象的配准问题,提出一种基于Visualization Toolkit（VTK）的在三维可视化平台环境下通过电磁定位系统进行配准的两步配准策略：首先,在虚拟空间和实际空间中的脊椎骨表面取几个特征点,进行粗配准;然后,在实际空间利用电磁定位探针在脊椎骨表面取点,并从虚拟空间提取对应的脊椎骨表面点;最后通过ICP（最近点迭代）算法进行精细配准.同时对ICP算法进行了模拟验证和精度分析,以脊柱模型骨为对象进行了脊柱手术导航配准精度实验,并进行了误差分析.结果表明这种配准方法简单可靠,在模型骨情况下最后的配准精度可达到临床手术的要求.

英文摘要：

This paper deals with the registration between preoperative CT images and intraoperative physical objects in the three-dimension computer-assisted spinal surgical navigation technology,and proposes a two-step registration strategy,which realizes the registration by an electromagnetic positioning system on the three-dimension visualization platform based on Visualization Toolkit（VTK）.In this strategy,several feature points are extracted on a spine bone surface respectively in the virtual space and in the physical space for coarse registration,an electromagnetic positioning probe is used to extract points on the spine surface in physical space,and the corresponding points are extracted in the virtual space.Moreover,the ICP（Iterative Closest Point） algorithm is used to complete a fine registration.The ICP algorithm is then validated by simulation and the accuracy of it is also analyzed.Finally,a registration experiment is performed with a spine model to evaluate the accuracy of the proposed method,followed with an error analysis.The results show that the proposed registration method is simple and reliable,and that the final registration accuracy for spine model meets the finical surgery requirements well.