Navab Nassir, Wiesner Stefan, Benhimane Selim, Euler Ekkehard, Heining Sandro Michael
TU Munich, Germany.
Med Image Comput Comput Assist Interv. 2006;9(Pt 1):551-60. doi: 10.1007/11866565_68.
The problem of positioning mobile C-arms, e.g. for down the beam techniques, as well as repositioning during surgical procedures currently requires time, skill and additional radiation. This paper uses a Camera-Augmented Mobile C-arm (CAMC) to speed up the procedure, simplify its execution and reduce the necessary radiation. For positioning the C-arm in down-the-beam position, the pre-operative diagnostic CT is used for defining the axis. Additional CT visible markers on patient's skin allow the CAMC's optical camera to compute the C-arm's pose and its required displacement for positioning. In the absence of electronically controlled mobile C-arms, the system provides step-by-step guidance to surgical staff until the final position is achieved. At this point, the surgeon can acquire an X-ray to ensure the correct positioning. In the case of intra-operative repositioning, no pre-operative CT is required. X-ray/Optical markers allow the visual servoing algorithm to guide the surgical staff in C-arm repositioning using CAMC's optical camera. This work paves the path for many possible applications of visual servoing in C-arm positioning and in surgical navigation. Experiments on phantom and a cadaver study demonstrate the advantages of the new methods.
移动C形臂的定位问题，例如用于束下技术时的定位，以及在手术过程中的重新定位，目前需要时间、技能和额外的辐射。本文使用一种摄像头增强型移动C形臂（CAMC）来加快手术过程、简化操作并减少所需的辐射。为了将C形臂定位在束下位置，术前诊断CT用于确定轴线。患者皮肤上额外的CT可见标记使CAMC的光学摄像头能够计算C形臂的姿态及其定位所需的位移。在没有电子控制移动C形臂的情况下，该系统会为手术人员提供逐步指导，直到达到最终位置。此时，外科医生可以获取X光片以确保定位正确。在术中重新定位的情况下，不需要术前CT。X光/光学标记使视觉伺服算法能够使用CAMC的光学摄像头在C形臂重新定位时指导手术人员。这项工作为视觉伺服在C形臂定位和手术导航中的许多可能应用铺平了道路。在模型上进行的实验和尸体研究证明了新方法的优势。
