A Passive Snake-Like Arm Based on Wire-driven Mechanism for Laparoscopic Surgery

Abstract

In this paper, a passive snake-Like arm based on wire-driven mechanism is proposed, which can be connected with remote center of motion (RCM) mechanism to form a laparoscope-holder robot and be used in laparoscopic surgery. The purpose of the snake-Like arm is to replace traditional multi-joint manipulator, making it possible for the robot to assist the surgeon in the best position in a surgery. The snake-Like arm consists of a main body composed of four arm units and a wire locking device with 12 wire locking units. The arm units are connected by hook hinges. Four classes force amplificatory structure is adopted in the wire locking unit. The detail structure and working principle of the wire locking device are proposed in this paper. The wire tensioning and guiding mechanism as well as the layout of wires are also introduced in this paper. Mechanical calculation of the force amplicatory structure is proposed in this paper to ensure that sufficient locking force can be provided. The workspace of the snake-Like arm is drawn by simulation, and the large workspace allows the snake-Like arm to be used in most laparoscopic surgeries.