Bimanual Endoscopic Robot for Neurosurgery

Abstract

In recent decades, improvements in neurosurgical care have been driven by technological advances such as frameless stereotaxy and endoscopy. Endoscopy enables navigation through the clear fluid-filled ventricular system of the brain instead of through healthy brain tissue enabling minimally invasive treatment of tumors, cysts, hydrocephalus and epileptogenic lesions [1]. Twenty percent of brain tumors lie either adjacent to, or inside, the ventricles, and endoscopy has had a major impact in their treatment leading to reductions in morbidity and procedure time [2]. Despite this progress, significant difficulties remain. A major challenge is that most endoscopes force clinicians to perform one-handed surgery even though many neurosurgical tasks require two hands. For example, one hand can retract healthy tissue while the second removes a lesion. A second challenge is that existing tools are mounted on straight rigid shafts. This forces the surgeon to pivot the endoscope about the burr hole in the skull to move the tool inside the brain. This pivoting motion can damage healthy brain tissue adjacent to the surgical corridor and so limit the size of tumors that can be safely accessed endoscopically. An ideal system for overcoming these limitations would enable the endoscope orientation to remain relatively fixed during a procedure and allow the surgeon to manipulate multiple dexterous tools within a workspace volume located at the endoscope’s tip. The contribution of this paper is to present a robotic two- armed endoscope (Fig. 1) that overcomes these challenges along with preliminary validation results for a bimanual task. Notable prior results on the design of multi-armed robotic neuroendoscopes include [3-5]. The present work differs from those results in that both the arms and the tools (e.g., forceps, scissors, bipolar cautery, suction) are designed as small, easily-sterilizable and replaceable modules that can be individually swapped during a procedure. This enables intraoperatively exchange of either a tool or a robotic arm without the risk involved in removing and reinserting the endoscope in the brain.