Towards a needle driver robot for radiofrequency ablation of tumors under continuous MRI

This paper presents an initial design and feasibility study for a 1-DOF Magnetic Resonance Imaging (MRI) compatible needle driver robot for radiofrequency ablation (RFA). This initial design and study is necessary to further understand how to improve on many of the shortcomings in the standard RFA procedure. Combining needle driving with advanced image tracking techniques could provide improved solutions to these clinical limitations. In this paper, we present a hydraulically-actuated 1-DOF needle driver robot that is capable of advancing a radiofrequency (RF) probe into tissue at controllable velocities and positions within an MRI scanner, while collecting force feedback data and maintaining all standards of MRI-compatible design. We also present a method of interfacing the robot with a PHANToM haptic feedback device controlled from outside the MRI scanning room. Experiments demonstrating the PHANToM´s ability to receive force feedback and guide the RFA tool to a tumor nodule within a phantom breast model while continuously imaging within MRI have been presented. Our haptic feedback system enabled us to detect normal vs. tumor phantom tissue in the preliminary experiments. Our experimental results demonstrate the compatibility of the entire system for operation during continuous MRI imaging.