Single-Master Dual-Slave Surgical Robot with Automated Relay of Suture Needle

Automating ubiquitous surgical subtasks such as suturing makes surgery more efficient, e.g., reduction of surgeon fatigue and/or surgery time. However, fully autonomous control in a surgical robot is still difficult due to individual differences in layout and deformation of human organs. In this paper, we propose a system consisting of a single master and dual slave, in which the operator commands one of the slaves manually through a master and the other slave autonomously moves. The operator inserts the needle to organ manually using one of the slaves (Slave A1) with a master. The other slave (Slave A2) automatically grasps the tip of the needle and pulls it out from the organ, and hands the needle back to Slave A1 automatically. Finally, Slave A1 regrasps the needle and the suturing is performed by repeating this procedure. The estimated external force is used to recognize the needle insertion by Slave A1, which is manually controlled with the master. This recognition of external force is used as a trigger to start the autonomous approach of Slave A2 to grasp the needle. We conducted single throwing and reinsertion in the experiment and compared the completion time using the proposed system and conventional bimanual teleoperation. The completion time was decreased by an average of 20% in total.