Stackable 4-BAR Manipulators for Single Port Access Surgery

This paper proposes a new robotic manipulator using stackable 4-BAR mechanisms for single port access (SPA) surgery where the operation is performed by inserting multiple manipulators through one small body cavity. The proposed manipulator has the advantage that all actuators are able to be separated from the driving mechanism. In other words, it is possible to separate the electrical actuators from the mechanical linkage/joint components in the manipulators. Thus, the robotic manipulators, including the working joints and linkages, can be fabricated using selective materials that are light-weight and slim so that the multiple manipulators can be inserted through one small cavity. Moreover, since the suggested manipulator makes use of an individual 4-BAR mechanism to drive each independent joint, it is structurally strong. Using the kinematic model, we conduct a kinematic synthesis (design methodology) because the operating range of each working joint is usually limited by the design parameters of 4-BAR. Finally, we show that the stackable 4-BAR manipulator is a good alternative for SPA surgery through numerical simulations and implementation of the proposed manipulator.