Needle targeting under C-arm fluoroscopy servoing

This paper describes a method for translational and orientational alignment of a robotic needle driver based on image servoing and x-ray fluoroscopy. The translational process works by segmenting the needle in a frame-grabbed fluoroscopic image and then commanding the robot to automatically move the needle tip to the skin entry point. The orientational alignment is then completed based on five different positions of the needle tip. Previously reported fluoroscopy servoing methods use complex robot-image registration algorithms, fiducial markers, and two or more dissimilar views that included moving the fluoroscope. Our method aligns the needle using one setting of the fluoroscope so that it does not need to be moved during the alignment process. Sample results from both the translational and orientational steps are included.