Steerable Laparoscopic Cable-Ring Forceps

Laparoscopic surgery is carried out using long and slender endoscopes and instruments that are inserted through small incisions in the abdominal wall. Current endoscopes and instruments are rigid and have the drawback that their motion is restricted to 4-degrees of freedom (DOF). This paper describes a 6-DOF steerable laparoscopic grasping forceps incorporating a novel and very simple “cable-ring” mechanism consisting out of a ring of cables surrounded by two coil springs. Methods are described to increase stiffness and to improve manual control, resulting in a well-working prototype suitable for commercialization. The paper ends with a discussion on a number of cable-ring variants suitable for challenging new steerable designs in the future.