Influence of the localization strategy on the accuracy of a neurosurgical robot system

Abstract

Precise navigation of surgical instruments is one of the most important features of autonomous surgical robots. In this paper, we introduce a concept of robot localization strategy and analyse its influence on the overall application error of a robot system for frameless stereotactic neurosurgery named RONNA. Localization strategies utilize specific angles at which the robot can approach a target point, orientations, and types of movement during the procedure of physical space fiducial marker localization and positioning to the target points. The localization strategies developed in this study are a neutral orientation strategy (NOS), an orientation correction strategy (OCS) and a joint displacement minimization strategy (JDMS). To evaluate the robot positioning performance with the localization strategies applied, we performed laboratory phantom measurements using a different number of fiducial markers in the registration procedure. When three, four, and five fiducial markers were used, the application error for the NOS was 1.571±0.256 mm, 1.397±0.283 mm, and 1.327±0.274 mm, and for the OCS, it was 0.429±0.133 mm, 0.284±0.068mm, and 0.260±0.076 mm, respectively. The application error for the JDMS was 0.493±0.176 mm with four and 0.369±0.160 mm with five fiducial markers used