Comparative in-vitro study of contact and image-based rigid
registration for computer-aided surgery

Ofri Sadowsky, Ziv Yaniv, and Leo Joskowicz

School of Computer Science and Engineering
The Hebrew University of Jerusalem, Jerusalem 91904, Israel.

Abstract:

We present an in-vitro study of rigid registration methods for
computer-aided surgery.  The goal of the study is to empirically obtain
accuracy measures under optimal laboratory conditions and to identify the
weak links in the registration chain.  Specifically, we investigate two
common registration methods: contact-based registration and image-based
landmark registration.  We establish a framework for comparing the accuracy
of both methods and describe phantoms, protocols, and algorithms for tool
tip calibration, contact-based registration with an optical tracker,
fluoroscopic X-ray camera calibration, and fluoroscopic X-ray image-based
landmark registration.  We report an average accuracy of 0.5mm (1.5mm
maximum) and 2.75mm (3.4mm maximum) for contact-based and image-based
landmark registration, respectively.  Based on our findings, we identify
the camera calibration as being the main source of error in image-based
landmark registration.  We propose protocol improvements and algorithmic
refinements to improve the accuracy of image-basedr landmark registration.


Keywords: registration, image-based registration, contact-based
registration, accuracy measurements, fluoroscopy, tracking.

Published in: Computer-Aided Surger, Vol. 7(4), 2002, pp. 223-236.