García Jaime, Thoranaghatte Ramesh, Marti Gaetan, Zheng Guoyan, Caversaccio Marco, González Ballester Miguel A
MEM Research Centre, University of Bern, Switzerland.
Int J Med Robot. 2008 Mar;4(1):87-93. doi: 10.1002/rcs.180.
In this paper, we present a new method for the calibration of a microscope and its registration using an active optical tracker.
Practically, both operations are done simultaneously by moving an active optical marker within the field of view of the two devices. The IR LEDs composing the marker are first segmented from the microscope images. By knowing their corresponding three-dimensional (3D) position in the optical tracker reference system, it is possible to find the transformation matrix between the referential of the two devices. Registration and calibration parameters can be extracted directly from that transformation. In addition, since the zoom and focus can be modified by the surgeon during the operation, we propose a spline based method to update the camera model to the new setup.
The proposed technique is currently being used in an augmented reality system for image-guided surgery in the fields of ear, nose and throat (ENT) and craniomaxillofacial surgeries.
The results have proved to be accurate and the technique is a fast, dynamic and reliable way to calibrate and register the two devices in an OR environment.
在本文中，我们提出了一种使用有源光学跟踪器对显微镜进行校准及其配准的新方法。
实际上，通过在两个设备的视野内移动有源光学标记，这两个操作可以同时完成。首先从显微镜图像中分割出构成标记的红外发光二极管。通过知道它们在光学跟踪器参考系统中的相应三维（3D）位置，就有可能找到两个设备参考系之间的变换矩阵。配准和校准参数可以直接从该变换中提取。此外，由于在手术过程中外科医生可以修改变焦和聚焦，我们提出了一种基于样条的方法来将相机模型更新到新设置。
所提出的技术目前正在用于耳鼻喉科（ENT）和颅颌面外科手术的图像引导手术的增强现实系统中。
结果证明是准确的，并且该技术是在手术室环境中校准和配准这两个设备的快速、动态且可靠的方法。
