A Finger-like Mechanism for End-effector of Concentric Continuum Robot

Abstract

In medical field, the patient’s rapid recovery is top priority, making minimally invasive surgery the biggest concern. For this reason, many surgical robots have been developed to be small and to have more dexterous movement. Active cannulas also have been studied for a decade, which can move its end point using combination of some pre-curved elastic tubes. To control its end point, however, it requires whole tube set to be twisted or deformed. It is not only inefficient but also possesses a serious weakness in actual surgery. Therefore, it requires an end-effector with high-curvature without changing tube pose. In this paper, an end-effector installed at the end of inner tube is introduced which is possible to guide tools like camera and bend up to 180 degrees itself. Four-bar linkage is adopted to be made up this finger-like end-effector with fewer parts than existing high-curvature mechanisms. A prototype of 3mm outer diameter was built and a micro-camera was attached at the tip of the prototype. Images were taken by the micro-camera when the bending angle of the finger was at 0, 90, and 180 degrees. Experimental results demonstrate the end-effector has ability to control the angle of bending.