Development of a New 5 DoF Robotic Assistant System for Neurosurgery

Craniotomy and Brain Tumor Biopsy are sorts of neurosurgeries related to the brain. A craniotomy is a bone flap removal from the skull surface which is an essential procedure in open skull surgeries. A craniotomy can be a time-consuming process, and the large forces needed for the cutting process make surgeons exhausted before operating the critical brain tissue. As a result, the probability of further errors increases. On the other hand, Brain Tumor Biopsy is a high accuracy surgery that involves a needle insertion to the tumor through a specific pre-planned trajectory. Surgeons still use a stereotactic frame as needle guidance. This frame is a half-century technology that can involve human errors during measurement and mounting processes. Nowadays, High stiffness robotic systems can achieve precise positioning and guidance without frames, save time and effort, and enhance safety. This paper presents a new 5 DoF robotic-assistant system that can be used in both Surgeries. This system can reach any point on the surface of the patient's skull with different orientation angles within the proposed system workspace. Based on motion requirements and skull shape, decoupled remote center-of-motion (RCM) mechanisms are selected for this system. The proposed system illustrates a high stiffness under the maximum bone drilling forces with a position error below 230 μm.