Controlling of Applied Force and Cornea Displacement Estimation in Robotic Corneal Surgery With a Gripper Surgical Instrument

BackgroundThe human eye consists of highly sensitive, hydrated, and relatively thin tissues, making precise control and accurate force estimation crucial in robotic eye surgery. This paper introduces a novel control method and state observer designed for a gripper surgical instrument used on the external ocular surface during robotic eye surgery.MethodsA novel state observer, operating in tandem with the controller, estimates the applied force. The proposed control approach, termed the Fixed-time Observer-based Sliding Mode Control (FOSMC), estimates the applied force by determining the gripper states and uses an eye model to calculate its displacement.ResultsThe performance of the proposed control method was compared with two other finite-time and asymptotic techniques across two scenarios. The results demonstrated excellent performance using the proposed method.ConclusionsThe FOSMC control technique effectively estimates the applied force during robotic eye surgery, making it a reliable solution for controlling the gripper surgical instrument.