Motion order system for the end effector of an instrument used in endoscopic surgery

Abstract

—Robotic operations of surgical instruments have greatly improved the workability of surgical operations. Even though they have high abilities, robotic surgery systems demand high cost and a large room space. As a solution to those problems, a number of instrument systems (Mid systems) have been proposed. Those systems are located at the middle position between conventional manual instrument systems and robotic surgery systems. This paper proposes some forceps that belong to the Mid systems. First, this paper discusses and sets up the conditions that should be considered when designing the Mid system instrument. This authors think it important to enable the forceps' jaws to rotate about its axis smoothly, to give the end effector with multi-d.o.f. motion (MDFM) the abilities of fine motion like that required for fine suturing work. Under the conditions of the Mid system, we discuss how we order the many motions of the instrument with MDFM by means of only one hand (Motion order). This paper tried forceps 'A' that has some electric switches for the Motion order for minimizing the end effector's tremble that may be transferred from the hand ordering the MDFM motions. The trial operations show that the fine touches of the switches cause little trembling on the end effector of forceps 'A'. However, they also show that it seems difficult for the end effector to take the required pose speedily. To respond to another demand that the end effector's pose has to change speedily, this paper proposes forceps 'B' that has a new mechanism that can give the pose of the end effector by taking the hand pose as the required one for the end effector separately from the jaws' rotational motion. The trial operations show that the new mechanism enables us to easily change the pose of the end effector. Even so, they also show that, in rapid pose change, the operator felt it difficult to follow the procedure after the pose change of the end effector. This paper clarifies, to a certain extent, the relationships of the Motion order method by the hand and the abilities of the end effector of the forceps.