104 Design and Evaluation of a Concentric Tube Robot for Minimally-Invasive Endoscopic Pediatric Neurosurgery

Abstract INTRODUCTION: Neuroendoscopy is technically challenging due to the limited accuracy, dexterity, and reachability of the instruments. Surgical robots offer a potential solution; however, the unique and critically constrained workspace within the ventricle system poses major challenges. We have developed a novel concentric tube endoscopic robot used as a suction/irrigation tool as a solution and implemented it on a validated silicone hydrocephalic brain phantom. METHODS: Telescoping, pre-curved, superelastic nitinol tubes, 2.5 mm in diameter and driven by 1 stepper motor and 2 linear actuators, were controlled via a Novint Falcon master system. An analysis of the robot's reachable workspace and positioning accuracy was performed. The robot was positioned within a silicone phantom ventricle system and its dexterity and reachability was evaluated. Endoscopic third ventriculostomies (ETV) were performed using the robot in an analogous fashion to standard endoscopic techniques. RESULTS: The reachable workspace was an inverted cone with base diameter 18.4 mm and height 40 mm. The positioning accuracy was 0.99 mm. The observed accuracy, dexterity and reachability of the robotic tools exceeded that of standard endoscopic instruments, but at reduced velocity. The robot was able to successfully perform an ETV in the phantom brain without apparent injury to critical structures including the basilar artery. CONCLUSION: We have successfully developed a miniaturized, teleoperated, concentric tube robot for intraventricular neuroendoscopy with improved accuracy, dexterity, and reachability. An ETV in a brain phantom was successfully performed. Future work will focus on improvements in positioning accuracy, system responsiveness, and reachability and additional phantom and animal testing.