Title: Precision, repeatability and accuracy of Optotrak® optical motion tracking systems

Authors: Jill Schmidt, Devin R. Berg, Heidi-Lynn Ploeg, Leone Ploeg

Addresses: Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Ave., Madison, WI 53706-1572, USA. ' Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Ave., Madison, WI 53706-1572, USA. ' Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Ave., Madison, WI 53706-1572, USA. ' Human Mobility Research Centre, Queen's University and Kingston General Hospital, 76 Stuart St., Kingston, Ontario K7L 2V7, Canada

Abstract: In the field of biomechanics, optical motion tracking systems are commonly used to record human motion and assist in surgical navigation. Recently, motion tracking systems have been used to track implant and bone motion on a micron-level. The present study evaluated four different Optotrak® motion tracking systems to determine the precision, repeatability and accuracy under static testing conditions. The distance between the camera systems and the rigid body, as well as the tilt angle of the rigid body, did affect the resulting precision, repeatability and accuracy of the camera systems. The precision and repeatability, calculated as the within-trial and between-trial standard deviations, respectively, were less than 30 µm; with some configurations producing precision and repeatability less than 1 µm. The accuracy was less than 0.53% of the total displacement for the in-plane motion and less than 1.56% of the total displacement for the out-of-plane motion.

Keywords: reliability; precision; accuracy; Optotrak; measurement; optical motion tracking; human motion; rigid body; bias; active markers; experimental biomechanics; computational biomechanics; surgical navigation; implant motion; bone motion.

DOI: 10.1504/IJECB.2009.022862

International Journal of Experimental and Computational Biomechanics, 2009 Vol.1 No.1, pp.114 - 127

Available online: 30 Jan 2009 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article