Robust Distance Estimation With Out-of-Distribution Detection in Ophthalmic Surgery

OBJECTIVE: Micrometer-scale precision is vital for patient safety in ophthalmic surgery. Recent advancements in instrument-integrated optical sensors aim to accurately measure instrument-to-tissue distances. However, the reliability of these measurements is often hindered by segmentation errors caused by artifacts in the signal. METHODS: We propose a deep learning framework to identify optical coherence tomography (OCT) M-scans that fall outside the expected distribution. Our approach incorporates adaptive remote center of motion (RCM)-informed retinal modeling along with time series analysis to effectively detect and rectify segmentation errors. This method estimates retinal distances and their associated confidence levels by leveraging retinal models, instrument positions, and validated distance data. RESULTS: Validation tests conducted on ex vivo human eyes reveal that our pipeline achieves an $88.8 \%$ accuracy in identifying out-of-distribution (OOD) measurements. Furthermore, distance estimation improved by $89 \%$ and $93 \%$ when compared to two existing methods, resulting in an overall mean absolute error (MAE) of less than $40 \,\mathrm{\mu }\mathrm{m}$ across diverse conditions, including scans with blood and obstructions. CONCLUSION: This research enhances the accuracy of instrument-to-retina distance estimation, thereby contributing to improved patient safety in ophthalmic surgical procedures. SIGNIFICANCE: The proposed method has potential applications beyond ophthalmic surgery, offering benefits to a variety of surgical disciplines and sensor-equipped instruments.