🤖 AI Summary
In autonomous robotic subretinal injection, tissue deformation induces needle-tip localization errors and misalignment with the target retinal layer. Method: This paper proposes an iOCT-guided, deformation-aware closed-loop control framework. It achieves millisecond-scale tracking of instrument-tissue relative pose via dense B5-scan sampling, real-time segmentation, dynamic virtual targeting-layer modeling between the ILM and RPE, and 3D scene reconstruction. It introduces, for the first time, deformation-compensated motion control based on virtual anatomical layers during subretinal injection, enabling adaptive adjustment of insertion depth. Results: In ex vivo porcine eye experiments, subretinal bleb formation success increased from 35% to 100%, with significant improvements in needle-tip localization accuracy and system robustness. This work represents the first integration of real-time deformation sensing and virtual-layer-based closed-loop targeting within an autonomous ophthalmic surgical system, establishing a new paradigm for high-precision, minimally invasive intraocular interventions.
📝 Abstract
Robotic platforms provide repeatable and precise tool positioning that significantly enhances retinal microsurgery. Integration of such systems with intraoperative optical coherence tomography (iOCT) enables image-guided robotic interventions, allowing to autonomously perform advanced treatment possibilities, such as injecting therapeutic agents into the subretinal space. Yet, tissue deformations due to tool-tissue interactions are a major challenge in autonomous iOCT-guided robotic subretinal injection, impacting correct needle positioning and, thus, the outcome of the procedure. This paper presents a novel method for autonomous subretinal injection under iOCT guidance that considers tissue deformations during the insertion procedure. This is achieved through real-time segmentation and 3D reconstruction of the surgical scene from densely sampled iOCT B-scans, which we refer to as B5-scans, to monitor the positioning of the instrument regarding a virtual target layer defined at a relative position between the ILM and RPE. Our experiments on ex-vivo porcine eyes demonstrate dynamic adjustment of the insertion depth and overall improved accuracy in needle positioning compared to previous autonomous insertion approaches. Compared to a 35% success rate in subretinal bleb generation with previous approaches, our proposed method reliably and robustly created subretinal blebs in all our experiments.