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

Abstract

BACKGROUND: The 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. METHODS: A 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. RESULTS: The 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. CONCLUSIONS: The FOSMC control technique effectively estimates the applied force during robotic eye surgery, making it a reliable solution for controlling the gripper surgical instrument.