MRI-Compatible Hydraulic Drive Needle Insertion Robot

In recent years, the Magnetic Resonance Imaging (MRI) offers high-contrast images of soft tissue to monitor the ablation procedure, an MRI-compatible robotic system aiming to target the lesions with high precision inside the MRI scanner for better intraoperative procedure is necessary. This paper presents an MRI-compatible hydraulic drive needle insertion robot for in-bore MRI-guided minimally invasive stereotactic neurosurgery. According to the principle of communicating vessel, we designed an actuator based on linear pistons and cylinders to drive the robot. A Scotch yoke mechanism is utilized to change the linear motion of the pistons into rotational. To achieve accurate control of the designed robotic system, we utilize grating scales and optical fiber to constitute a MRI-compatible linear encoder. Intensive experimental studies have been performed, the obtained average positional accuracy of the designed robotic system on X-axis, Y-axis, Z-axis, Pitch-axis and Roll-axis is 0.518mm, 1.21mm, 0.898mm, 1.32° and 1.64° respectively.