A skeletal prototype of surgical arm based on dual-triangular mechanism

The parallelogram-based remote center of motion (RCM) mechanism used for robotic minimally invasive surgery (MIS) manipulators generates a relatively large device footprint. The consequence being larger chance of interference between the robotic arms and restricted workspace, hence obstruct optimal surgical functioning. A novel mechanism with RCM, dual-triangular linkage (DT-linkage), is introduced to reduce the occupied space by the linkage while keeping sufficient space around the incision. Hence, the chance of collisions among arms and tools can be reduced. The concept of this dual-triangular linkage is proven mathematically and validated by a prototype. Auxiliary mechanisms are introduced to remove the singularity at the fully folded configuration. The characterized footprints of this new linkage and the one based on parallelograms are analyzed and compared.