Influence of the Localization Strategy on the Accuracy of a Neurosurgical Robot System

Abstract

SummaryPrecise 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.

RobUSt–An Autonomous Robotic Ultrasound System for Medical Imaging

“…Based on the localization of 20 points uniformly distributed inside the phantom, the mean Euclidean error is 1.19±0.76mm. However, authors expect larger positioning errors when scanning uneven surfaces, due to changes in orientation of the robot end-effector [36].…”

Clinical application of the RONNA G4 system – preliminary validation of 23 robotic frameless brain biopsies

“…The screw caps have a mechanical interface for standard medical retroreflective snap-fit spherical markers (NDI – Northern Digital Inc., Waterloo, Canada). When it comes to software features, RONNA G4 uses a new and improved algorithm for autonomous localization of fiducial markers in the image space ( 24 ), an algorithm for robot position planning with respect to the patient in the physical space ( 25 ), a novel pair-point correspondence algorithm for the patient registration from the image space to the physical space ( 30 ), and a novel method for determining an optimal robot localization strategy in the physical space ( 31 ). Other major features that differentiate the RONNA G4 from the current state of-the-art robotic neuronavigation systems are a specifically designed universal mobile platform ( 32 ) and a new and accurate non-contact localization system ( 18 ).…”

Frameless stereotactic brain biopsy: A prospective study on robot‐assisted brain biopsies performed on 32 patients by using the RONNA G4 system

“…Finally, the minimal enclosing circle is fitted to acquire the centre coordinates and the radius of the circular marker. Since the RONNA robot is an articulated six‐joint revolute robot, we have experimentally evaluated multiple localisation strategies; the evaluation results are presented in our earlier research 30 . The strategy that significantly improves the robot positioning accuracy is the orientation correction strategy (OCS) in which the tool orientation (three Euler angles) is kept constant in the localisation and operation phases.…”