MPD$^2$-Router: Mask-aware Multi-expert Prior-regularized Dual-head Deferral Router in Glaucoma Screening and Diagnosis
Summary
The MPD$^2$-Router is a mask-aware multi-expert deferral framework designed to improve glaucoma screening safety by routing difficult or uncertain cases to human experts. This system recasts ophthalmic triage as a constrained human-AI routing problem, determining whether to defer a case and to which available expert. It integrates a dual-head deferral/allocation policy with mask-aware Gumbel-sigmoid gating to enforce per-sample availability, while fusing uncertainty, morphology, image-quality, and out-of-distribution signals. The training employs an asymmetric cost-sensitive objective with an augmented-Lagrangian deferral budget, a group-specific distribution prior, and a rank-majorization JS regularizer to prevent expert collapse without forcing uniform allocation. Evaluated across three cross-national glaucoma cohorts (REFUGE, CHAKSU, ORIGA) using a frozen REFUGE-trained backbone, MPD$^2$-Router significantly reduces clinical cost and enhances Matthews Correlation Coefficient (MCC) compared to AI-only approaches at a moderate deferral rate, demonstrating Pareto-optimality in F1-MCC-cost and robustness under cross-domain shift.
Key takeaway
For Computer Vision Engineers developing medical diagnostic AI, consider implementing a deferral router like MPD$^2$-Router to enhance safety and efficiency. Your system should account for expert availability, workload balance, and asymmetric diagnostic costs to achieve Pareto-optimal performance and robustness across diverse patient cohorts. This approach can significantly lower clinical costs and improve diagnostic accuracy by intelligently routing challenging cases to human oversight.
Key insights
MPD$^2$-Router optimizes glaucoma screening by routing complex cases to available human experts, balancing cost and diagnostic accuracy.
Principles
- Integrate multiple signals for robust case difficulty assessment.
- Enforce expert availability for practical deferral systems.
- Balance expert workload to prevent collapse.
Method
The MPD$^2$-Router uses a dual-head deferral/allocation policy with mask-aware Gumbel-sigmoid gating, fusing uncertainty, morphology, image-quality, and OOD signals. Training involves an asymmetric cost-sensitive objective, augmented-Lagrangian budget, group-specific prior, and rank-majorization JS regularizer.
In practice
- Apply mask-aware gating for resource-constrained routing.
- Utilize asymmetric cost functions for medical diagnostics.
- Combine multiple uncertainty signals for robust deferral.
Topics
- Glaucoma Screening
- Learning-to-Defer
- Multi-expert AI
- MPD$^2$-Router
- Ophthalmic Triage
Best for: Computer Vision Engineer, AI Scientist, Machine Learning Engineer, Research Scientist
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Editorial summary, takeaway, and curation by AIssential. Original article published by Artificial Intelligence.