Autonomous neuro-registration for robot-based neurosurgery

Neuro-registration is of primary importance as it has a bearing on the accuracy of neurosurgery. Although the accuracy of surgical robots is within the acceptable medical standards, the overall surgical accuracy is dictated by the errors in the neuro-registration process. The purpose of this work is to automate the neuro-registration process to improve the overall accuracy of the robot-based neurosurgery.

A highly accurate 6-degree-of-freedom Parallel Kinematic Mechanism (6D-PKM) robot is used for both neuro-registration and neurosurgery. In neuro-registration, after measurement of points in the medical image space, the end-platform of the 6D-PKM surgical robot carrying the camera will autonomously navigate towards the fiducial markers to measure its coordinates in the real patient space. An accurate relationship between the medical image space and the real patient space is established, and the same robot will navigate the surgical tool to the target.

In order to validate the proposed method for autonomous neuro-registration, experiments are performed using four phantoms. The four phantoms are as follows: PVC skull model, two acrylic blocks and a glass jar with coaxial shells. These phantoms are specifically designed to simulate the neurosurgical process. All the phantoms are registered successfully using the above-stated method. After autonomous neuro-registration, the coordinates of the target point are determined. Neurosurgery validation is carried out by attaching a 1-mm-diameter needle to the robot platform, which is autonomously traversed to reach the target point passing through the two 2-mm-diameter coaxial holes. The experiments are repeated, and the results reveal very good repeatability.

A method for autonomous neuro-registration has been developed. The robot has been successfully registered using the above method. After successful neuro-registration the overall accuracy of the robot-based neurosurgery is considerably improved. The other benefits of the above method are as follows: elimination of line-of-sight problem, no need of extra unit for neuro-registration, less time for registration, intraoperative registration, human error reduction and low cost.