Abstract Robot-assisted surgical systems comprising manipulators with remote centers of motion are quite popular in minimally invasive surgery applications. This paper examines the mechanical safety features for such manipulators in three levels: design of the mechanism with a remote center of motion that does not interfere with the surgical tools and the surgeon, gravity balancing of the mechanism, utilsation of series elastic actuators with variable stiffness. First, alternative kinematic structures in the literature are examined, and a novel serial kinematic architecture for minimally invasive surgery applications is proposed as a serial 3 degrees-of-freedom manipulator with a circular arc. Gravity balancing solutions with springs and/or counter-masses are evaluated. Series elastic actuator designs are discussed, and a new solution developed for gradually softening behavior is presented. The investigated safety measures are applied for an endoscope holder manipulator for endonasal skull base surgeries as a case study. The design and prototype tests of the gravity-balanced manipulator and series elastic actuators are presented. The effectiveness of the mechanical safety measures is verified via the test results.
Yilmaz et al. (Thu,) studied this question.