Active Needle Steering System for Percutaneous Prostate Intervention in High-field MRI

This paper presents the design of a magnetic resonance imaging (MRI) compatible needle steering system actuated by piezoelectric actuators for prostate brachytherapy and biopsy. Our guiding vision is to design a modular needle driver that can be coupled to a generic gross positioning stage to enhance MRI-guided prostate surgery accuracy and decrease operational time. After reviewing pertaining robot assisted needle driver systems in MRI, ultrasound and computed tomography (CT) environments, we articulate the design challenges and requirements of robotic system for close bore interventional MRI surgery. The paper presents a modular 3-degrees-offreedom (DOF) needle platform coupled with a representative MRI-compatible 3-DOF x−y−z stage. This system is proposed to serve as a slave robot to deliver radioactive seeds in an MRIguided force feedback teleoperation framework. Moreover, it suffices to be a generic robot platform to provide the needle positioning and orientation task in a diverse array of proposed needle steering scenarios. With a kinematically parallel robot embodiment, the positioning module provides linear position control with high system rigidity. The modular needle driver simultaneously provides needle cannula rotation and independent cannula and stylet prismatic motion. The device mimics the manual physician gesture by two point grasping and direct force measurement of needle axial puncture and lateral forces by two fiber optic force sensors. The CAD model and the fabricated prototype are presented and the experiment with phantom trial is analyzed to demonstrate the system compatibility.