Fast Marker Based C-Arm Pose Estimation

Abstract. To estimate the pose of a C-Arm during interventions therapy we have developed a small sized X-Ray Target including a special set of beads with known locations in 3D space. Since the patient needs to remain in the X-Ray path for all feasible poses of the C-Arm during the intervention, we cannot construct a single marker which is entirely visible in all images. Therefore finding 2D-3D point correspondences is a non-trivial task. The marker pattern has to be chosen in a way such that its projection onto the image plane is unique in a minimal-sized window for all relevant poses of the C-Arm. We use a two dimensional adaption of a linear feedback shift register (LFSR) to generate a twodimensional pattern with unique sub-patterns in a certain window range. Thereby uniqueness is not achieved by placing unique 2D sub patterns side by side but by the code property itself. The code is designed in a way that any sub window of a minimal size guarantees uniqueness and that even occlusion...

• Type: Conference
• Year: 2008
• Where: MICCAI
• Authors: Bernhard Kainz, Markus Grabner, Matthias Rüther
• Keywords: Certain Window Range, Medical Imaging, MICCAI 2008, Size Guarantees Uniqueness, Unique 2D Sub