A robotic case study: optimal design for laparoscopic positioning stands

The positioning stand could help the surgeon to position and lock endoscopic tools without the need for an assistant surgeon. The kinematic configuration of the positioning stand comprises two main parts, the arm (for positioning) and the wrist (for orienting the tool). The main requirement of the wrist is to perform spherical movements around the incision point. A concentric multi-link spherical joint design has been developed for the wrist mechanism. The size synthesis is performed to minimize the overall size of wrist and also to maximize its range of angular movements. The type synthesis of the positioning arm has led to SCARA configuration, as a balanced and easy to move arm configuration. The size synthesis of the arm is carried out with the goal of minimizing its overall dimensions, based on reachable workspace and manipulability of the arm. The integration of the wrist and arm is performed by optimizing the orientation of wrist in such a way that the interference between the wrist and the workspace of surgeon is minimized