Design of a Novel Bimanual Robotic System for Single-Port Laparoscopy

This paper presents the design and fabrication of Single-Port lapaRoscopy bImaNual roboT (SPRINT), a novel tele-operated robotic system for minimally invasive surgery. SPRINT, specifically designed for single-port laparoscopy, is a high-dexterity miniature robot, able to reproduce the movement of the hands of the surgeon, who controls the system through a master interface. It comprises two arms with six degrees of freedom (DOFs) that can be individually inserted and removed in a 30-mm-diameter umbilical access port. The system is designed to leave a central lumen free during operations, thus allowing the insertion of other laparoscopic tools. The four distal DOFs of each arm are actuated by on-board brushless dc motors, while the two proximal DOFs of the shoulder are actuated by external motors. The constraints generated by maximum size and power requirements led to the design of compact mechanisms for the actuation of the joints. The wrist is actuated by three motors hosted in the forearm, with a peculiar differential mechanism that allows us to have intersecting roll-pitch-roll axes. Preliminary tests and validations were performed ex vivo by surgeons on a first prototype of the system.