An improved surgical instrument without coupled motions that can be used in robotic-assisted minimally invasive surgery.

In order to enhance the dexterity of surgical instruments in robotic-assisted minimally invasive surgery, the robot is generally configured so as to have a wrist. However, this configuration has a problem in that there is a coupling of the motions of the wrist and the end-effector. In this paper an improved surgical instrument is proposed that eliminates the coupled motion using a compensation mechanism. The design concept behind the compensation mechanism can be applied to other types of surgical instruments. The performance of the proposed surgical instrument is validated by mechanical performance testing and animal experiments, which indicate that the problem of the coupled motion is successfully solved and the instrument is able to perform surgical tasks.