Design Of A Sliding-Pin In Eedle Driver For A Continuum Surgical Robot

MIS (Minimally Invasive Surgery) is advantageous in terms of improved treatment outcomes and reduced recovery time. Many surgical robotic systems have hence been developed to assist MIS due to the operation difficulties while using manual laparoscopic tools. In recent years, continuum surgical robots have been found appealing due to their inherent compliance, light weight, design compactness, and distal dexterity. However, the gripper, needle driver and other similar surgical end effectors for a continuum surgical robot cannot be actuated with adequate actuation forces: pulling the actuation line too hard will increase the risk of structural buckling and failure. Since these surgical end effectors have to generate sufficient gripping forces to make them clinically useful, this paper presents the design of a sliding-pin needle driver, specifically for the integration into a continuum surgical robot. The design aims at a proper gripping capability under a limited actuation force. Model-based design determination and finite element analysis were conducted to finalize the design features. A comparison of the output gripping forces among the sliding-pin needle driver, the large needle driver of the da Vinci EndoWrist tool and a manual laparoscopic needle driver, together with the experimental validations, indicates the effectiveness of the proposed design. It is expected that similar surgical end effectors for continuum surgical robots can be designed following the presented design approach.