Delta Robot Kinematic Calibration for Precise Robot-Assisted Retinal Surgery

Area of Science:

• Robotics
• Ophthalmic Surgery
• Mechatronics

Background:

• Ophthalmic robotic systems demand high precision for safe and effective surgical procedures.
• The Steady-Hand Eye Robot (SHER) is a next-generation system requiring precise kinematic control.
• Accurate kinematic modeling is crucial for minimizing errors in robotic-assisted eye surgery.

Purpose of the Study:

• To present the kinematic calibration of the delta robot component of the SHER system.
• To develop and apply a linear error model for compensating kinematic inaccuracies.
• To improve the overall precision of the ophthalmic robotic system for clinical applications.

Main Methods:

• Derived a linear error model based on geometric error parameters for the delta robot.
• Conducted experiments using laser sensors to measure displacement across different workspace ranges.
• Identified error parameters and applied them to the robot's kinematics for error compensation.
• Utilized Bernstein polynomials to fit and minimize residual errors post-calibration.

Main Results:

• Successfully identified and compensated for kinematic modeling errors in the delta robot.
• Achieved a significant reduction in the robot's error residuals after applying the calibration.
• Demonstrated that the calibrated delta robot meets the stringent precision requirements for ophthalmic surgery.

Conclusions:

• The kinematic calibration process effectively enhanced the precision of the SHER delta robot.
• The implemented error compensation strategy and use of Bernstein polynomials are vital for achieving clinical accuracy.
• This work contributes to the development of highly accurate robotic systems for ophthalmic interventions.