Calibration of a Mobile-Gantry CT Scanner for Surgical Navigation

• Main Author: Belkova, Anna
• Other Authors: Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))
• Language: en; en
• Published: 2013
• Subjects: intraoperative imaging; computer-assisted surgery; direct navigation
• Online Access: http://hdl.handle.net/1974/8252

In image-guided surgical navigation, instruments tools are tracked by a position sensor and their locations rendered along with the patient's anatomy. Conventional methods require an invasive, time-consuming and potentially uncertain process of intra-operative registration of the images to the patient. In a direct navigation system, such an intra-operative registration is replaced with pre-operative patient-independent calibration in a process that determines the relationship between the coordinate frame of imaging equipment and the coordinate frame of the position sensor. This dissertation presents a method for pre-operatively calibrating a direct navigation system that used an optical position sensor and a mobile gantry CT scanner. A custom bi-local calibration device was designed and manufactured, after which existing navigation software was augmented with components that used the pre-operatively determined transformation to provide image-guided surgical navigation. The resulting system was tested in an image-guided operating suite using plastic bone models. In the validation stage, the inherent error was less than 0.4 mm and the target registration error was approximately 1.6 mm for a ceiling-mounted position sensor and 0.7 mm for a portable position sensor. This accuracy is consistent with the best intra-operative registrations reported in the literature and this calibration method may be useful in future surgical systems. === Thesis (Master, Computing) -- Queen's University, 2013-09-05 12:53:08.994