Structural Design and Needle Deflection Prediction of Body-Mounted Breast Puncture Robot Modeled After a Compass

Magnetic Resonance Imaging -guided breast puncture robots have been widely used in recent years. A puncture robot with a body-mounted method can compensate for errors caused by respiratory motion. In this study, inspired by the structure of a compass, a body-mounted breast puncture robot modeled after a compass is proposed. A modular approach is used to design the structure of the robot, which is compact and easy to control, and its kinematics and workspace are analyzed and solved. Secondly, during the puncture process, the needle interacts with its surrounding tissues, which can cause the tip of the needle to deviate from its intended direction. To address this problem, needle bending modeling based on an improved virtual coil spring model is proposed to predict the needle tip deflection and improve the surgical accuracy. An experimental platform is also built to compare the model calculation results with the actual bending situation, using bionic tissue as the puncture object. The experimental results show that, within a certain degree of discretization, the bending path calculated by the improved virtual coil spring model basically matches the actual bending path, with a maximum error of 0.12 mm. the feasibility and accuracy of the model are proved.