Development of a novel robotic platform with controllable stiffness manipulation arms for laparoendoscopic single-site surgery (LESS).

Abstract

For current LESS robotic systems, the trade-off between dexterity and payload capability is always present. This paper presents a novel LESS robotic platform equipped with controllable stiffness manipulation arms. Each manipulation arm with an articulated section and a controllable stiffness continuum section (CSCS) can be switched between a 7-DoF compliant status and 5-DoF rigid status according to the operation requirement. Screw theory and product exponential formula are used to quantify the kinematic performance. The stiffness of the manipulation arm promotes 3.03 to 4.12 times from compliant to rigid CSCS with maximum payload of 10N in rigid status. The shortest rigid/compliant switching time is 5s. The precision of a tracking test and an ex vivo procedure verified the accuracy and effectiveness of the controllable stiffness manipulation arms. This robot could potentially improve the surgical performance and further expand robotic LESS procedures.