Design and Kinematics Analysis of a Novel MR-Compatible Robot for Needle Insertion

摘要

The MR-compatible robot for needle insertion has attracted increasingly attentions due to high precision in minimally invasive surgery. A robotic system for prostate brachytherapy has been designed and is actuated by five ultrasonic motors to realize needle orientation and insertion. The application of cable transmission leads to a compact and dexterous mechanism, because all the motors are placed in the base and the moving part of the mechanism becomes as light and small as possible. What's more, placing the motors far away from the center of the scanner will eliminate artifacts and distortion of the MR images caused by the motors. The displacement analysis is carried out and the reachable workspace is obtained. Jacobian matrix is deduced in velocity mapping model for dimensional synthesis in further study. Configuration singularities are analyzed on the basis of Jacobian matrix.