Double-screw-drive mechanism incorporated multi-DOF robotic forceps manipulator for minimally invasive surgery

Abstract

This paper proposes a novel bending technique with a screw drive mechanism, which enables omni-directional bending motion by rotating two linkages, each consisting of a right-handed screw, a universal joint and a left-handed screw. We call this mechanism as double-screw-drive (DSD) mechanism. The DSD mechanism was applied to a robotic forceps manipulator for laparoscopic surgery. The DSD mechanism has three linkages, and opening and closing motions of a gripper are attained by rotating a third linkage. The developed DSD forceps manipulator realizes bending motion without using wires. Therefore, it has high rigidity, and it can bend 90 degrees in any arbitrary direction. Furthermore, in order to control the DSD forceps as a teleoperation system, joystick type manipulator was built and servo systems were constructed. Tracking control experimrnts as well as a lifting experiment for a pig's liver were executed. Experimental results showed that the required design specifications were fulfilled. Thus, the viability of the DSD forceps was demonstrated.