Retinal Surgical Field Realignment Based on Master-Slave Dual-Arm Surgical Robot

In ophthalmic surgery, realigning retinal field is a common practice to check the lesion area by rotating the eyeball. It can be a challenging task for teleoperated surgical robots as it requests high precision of hands coordination comparing with traditional surgery. Current ophthalmic surgical robots are mainly designed with one-to-one mapping mode, which requires surgeons to operate with two hands. This article proposes a single master and dual-slave control method to improve the coordination of slave robots. Firstly, motion constraints between slave arms are analyzed. To solve the motion equation of master-slave mapping, Gauss-Newton Iteration is implemented to achieve the real-time motion coordination. Secondly, an adaptive impedance control is adopted to ensure the contact force between end-effectors and sclera within the threshold, preventing the eyeball from stretching and compressing. Finally, the effectiveness and practicability of the proposed method are verified on the established ophthalmic surgical robot platform by fixed trajectory and free trajectory experiments. Note to Practitioners—This paper was motivated by the problem of dual-arm control in robot-assisted retinal surgery. Related previous studies mainly focus on the control of teleoperated surgical robots based on one-to-one mapping mode between the master and slave robots. However, to the limited coordination of human hands, the master robots may perform poor coordination so that one task is hard to be accomplished by salve robots at same time. Especially when the requirement of task is complex and operation is precise, the accuracy and safety may not be guaranteed by one-to-one mapping mode. To solve these problems, this article seeks to develop a single master and dual-slave control method to improve the coordination of slave robots. The proposed method can be integrated into eye surgical robot to help the surgeons perform surgery. Our method will significantly facilitate its practical applications in improvement of surgery safety and reduction of the operation burden and training cost of the surgeons.