Design and experiment of surgical instrument without coupled motions for minimally invasive surgery

Abstract:

To increase the operation dexterity of surgical instruments in minimally invasive surgery (MIS), and improve manipulation performance of master-slave control, a novel surgical instrument without coupled motions used in MIS is designed. On the basis of analyzing the formation principle of coupled motions and existing methods of coupled motions elimination, a design method that steel wire crosses the centre of wrist shaft in the radial direction for surgical instrument used in MIS is proposed. The developed instrument has four DOFs and is driven by means of steel wire. Besides that, the instrument can realize quick replacement and useful information record as well. After researching kinematics of surgical instrument and master, master-slave control method for surgical instrument is proposed and experiments platform for master-slave control is established. The experimental results indicate that the position of instrument′s wrist in relation to two fingers remains unchanged in the process of surgical instrument's wrist moving individually, which means that the developed surgical instrument eliminates coupled motions and has good manipulation performance in master-slave control. The design method that steel wire crosses the centre of wrist shaft in the radial direction for surgical instrument used in MIS can eliminate coupled motions, and the developed surgical instrument is beneficial to surgical operation in MIS.