Evaluation and Comparison of Target Registration Error in Active and Passive Optical Tracking Systems.

Abstract

Optical tracking systems combined with imaging modalities such as computed tomography and magnetic reso-nance imaging are important parts of image guided surgery systems. By determining the location and orientation of sur-gical tools relative to a patient's reference system, tracking systems assist surgeons during the planning and execution of image guided procedures. Therefore, knowledge of the tracking system-induced error is of great importance. To this end, this study compared one passive and two active optical tracking systems in terms of their Target Registration Error. Two experiments were performed to measure the systems' accuracy, testing the impact of factors such as the size of the measuring volume, length of surgical instruments and environmental conditions with orthopedic procedures in mind. According to the performed experiments, the active systems achieved significantly higher accuracy than the tested passive system, reporting an overall accuracy of 0.063 mm (SD = 0.025) and 0.259 mm (SD = 0.152), respectively.