Steady-Hand Eye Robot 3.0: Optimization and Benchtop Evaluation for Subretinal Injection

TL;DR

This paper introduces the SHER 3.0, a robotic platform designed for precise subretinal injections, demonstrating optimized design and benchtop validation to meet clinical standards.

Contribution

The study presents a new cooperative robotic system with an optimized delta stage for subretinal injections, including a deflection model and validation experiments.

Findings

Tip accuracy <30 μm

Tip repeatability 9.3 μm and 0.02°

Deflections 20-350 μm/N

Abstract

Subretinal injection methods and other procedures for treating retinal conditions and diseases (many considered incurable) have been limited in scope due to limited human motor control. This study demonstrates the next generation, cooperatively controlled Steady-Hand Eye Robot (SHER 3.0), a precise and intuitive-to-use robotic platform achieving clinical standards for targeting accuracy and resolution for subretinal injections. The system design and basic kinematics are reported and a deflection model for the incorporated delta stage and validation experiments are presented. This model optimizes the delta stage parameters, maximizing the global conditioning index and minimizing torsional compliance. Five tests measuring accuracy, repeatability, and deflection show the optimized stage design achieves a tip accuracy of <30 $\mu$m, tip repeatability of 9.3 $\mu$m and 0.02{\deg}, and deflections between 20-350 $\mu$m/N. Future work will use updated control models to refine tip positioning outcomes and will be tested on in vivo animal models.