Registration of Computed Tomography Data to a Surgical Robot Using Fluoroscopy: A Feasibility Study

        We present a new semiautomatic method for registering preoperative CT scan data to a robot used intra-operatively for Total Hip Replacement Surgery. Our goal is to utilize anatomical features for registration markers. We use xray-fluoroscopy images to perform the registration. We developed a novel technique for calibration of these images with respect to the robot, such that a 3D projection line can be fully specified in robot space for each image pixel. The calibration uses an original radiolucent rod with removable metallic beads. We extract surface models from the CT-scan, define a distance between the surfaces and a beam of 3D lines, and find the pose of the surfaces that minimizes the distance to the lines using a statistically robust method, thus providing a registration. Our new registration method uses surface apparent contours to assign a positive distance to lines intersecting the surface. We compare our result with the registration obtained when using three metallic fiducial markers, or pins, corresponding to the clinical protocol, and representing the ground truth for the present study. Using CT scan and fluoroscopic images of a human femur, we measured the error at the pin locations. When one fiducial is used instead of three, the maximum registration error is two mm, which indicates that the new method is accurate enough to be used clinically.

By: Andre Gueziec, Peter Kazanzides (Integrated Surgical Systems), Bill Williamson (Integrated Surgical Systems) and Russell H. Taylor (Johns Hopkins Univ.)

Published in: RC20561 in 1996


This Research Report is available. This report has been submitted for publication outside of IBM and will probably be copyrighted if accepted for publication. It has been issued as a Research Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g., payment of royalties). I have read and understand this notice and am a member of the scientific community outside or inside of IBM seeking a single copy only.

Questions about this service can be mailed to .