Equivalent Mechanisms Techniques for Redesign of a Spherical Surgical Tool Manipulator

In the design of robotic manipulators for minimally invasive surgery (MIS), the spherical mechanism is a very important kinematic entity, since it can be used to mimic the constraint that the incision point provides to the surgical tool. In previous research by the authors, a bevel-gear-based spherical manipulator was designed whose actuators could be located on a fixed base link. In this paper, concepts of mechanism equivalency are applied to improving the manipulator design. The guidelines arrived at in this work can inform design of future spherical manipulators, especially those created with surgical tool manipulation in mind.