Design of a 1R1T planar mechanism with remote center of motion

Compared with traditional open surgery, minimally invasive surgery (MIS) is safer and more beneficial to patients' recovery. However, this type of surgery is an arduous task for doctors. Using robots to carry out MIS is a good choice. In this paper, a new remote-center-of-motion (RCM) mechanism is presented. First, the direct kinematics and inverse kinematics are analyzed. Second, singularity analysis is conducted based on the Jacobian matrix, and a three-dimensional workspace is sketched. Next, the motion/force transmission index is established using screw theory, and optimization design is conducted to improve the performance of the mechanism. Finally, workspace validation on a prototype is conducted. The proposed RCM mechanism has several advantages: a good actuation scheme, analytical direct kinematic solutions, and no singular configurations in the prescribed workspace. The proposed RCM mechanism is suitable for single minimal incision surgery, such as biopsy and cryosurgery. (C) 2020 Elsevier Ltd. All rights reserved.