Design of a dedicated five degree-of-freedom magnetic resonance imaging compatible robot for image guided prostate biopsy

In order to improve the current clinical application of magnetic resonance (MR)-guided prostate biopsies, a new, fully magnetic resonance imaging (MRI)-compatible solution has been developed. This solution consists of a five degree-of-freedom (5DOF) pneumatic robot, a programmable logic controller (PLC), and a software application for visualization and robot control. The robot can be freely positioned on the MR table. For the calibration of the robot and MR coordinate system, the robot's needle guide (NG) is used. The software application supports the calibration with image segmentation and graphic overlays and guides the user through the interventional planning process. After selecting a target point, the application calculates the needed movements via solving the kinematics of the robot and translating the adjustment into commands for the PLC driving the step motors of the robot. In case further adjustments are required, the software also allows for manual control of the robot, to position the NG according to the acquired MR images.