In vivo measurement of the frame-based application accuracy of the Neuromate neurosurgical robot

OBJECT The application accuracy of the Neuromate neurosurgical robot has been validated in vitro but has not been evaluated in vivo for deep brain stimulation (DBS) electrode implantations. The authors conducted a study to evaluate this application accuracy in routine frame-based DBS procedures, with an independent system of measurement. METHODS The Euclidian distance was measured between the point theoretically targeted by the robot and the point actually reached, based on their respective stereotactic coordinates. The coordinates of the theoretical target were given by the robot's dedicated targeting software. The coordinates of the point actually reached were recalculated using the Stereoplan localizer system. This experiment was performed in vitro, with the frame fixed in the robot space without a patient, for 21 points spatially distributed. The in vivo accuracy was then measured in 30 basal ganglia targets in 17 consecutive patients undergoing DBS for movement disorders. RESULTS The mean in vitro application accuracy was 0.44 +/- 0.23 mm. The maximal localization error was 1.0 mm. The mean (+/- SD) in vivo application accuracy was 0.86 +/- 0.32 mm (Delta x = 0.37 +/- 0.34 mm, Delta y = 0.32 +/- 0.24 mm, Delta z = 0.58 +/- 0.31 mm). The maximal error was 1.55 mm. CONCLUSIONS The in vivo application accuracy of the Neuromate neurosurgical robot, measured with a system independent from the robot, in frame-based DBS procedures was better than 1 mm. This accuracy is at least similar to the accuracy of stereotactic frame arms and is compatible with the accuracy required in DBS procedures.