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Children's National Health System

Academic institutionnorthamerica · us
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Research library7linked papers
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Selected work

Representative Papers

Fed-ADApt: Federated Anytime Depth Adaptation for Resource-Aware Medical Image Segmentation

Oct 02, 2026

This study addresses the challenge of computational heterogeneity in federated medical image segmentation, which often restricts the participation of resource-constrained institutions. To this end, we propose a deep adaptive federated learning framework built upon a UNet architecture that incorporates multi-depth supervision and hierarchical aggregation mechanisms. This design enables participating nodes to dynamically select training and inference depths according to their local computational budgets, thereby achieving joint optimization of resource allocation. Experimental results demonstrate that the proposed framework attains performance comparable to full-capacity models on 3D segmentation tasks while substantially reducing both training and inference overhead. By facilitating equitable and efficient collaboration across heterogeneous environments, this approach effectively empowers low-resource institutions to participate in federated medical analysis.

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Evaluating Biomedical Reranking for LLM-Based Question Answering over Longitudinal Clinical Notes

Oct 01, 2026

This study addresses the challenge of degraded patient question-answering quality caused by fragmented evidence and heterogeneous terminology in longitudinal clinical records by constructing a localized retrieval-augmented generation (RAG) pipeline. Methodologically, it integrates PubMedBERT-based dense retrieval with BM25 lexical retrieval via weighted reciprocal rank fusion, and incorporates a MedCPT cross-encoder for biomedical reranking to optimize evidence selection. Results demonstrate that the top-10 retrieval hit rate increases from 46.6% to 60.6%, while the answer accuracy of Qwen3-8B improves from 44.8% to 48.6%. This work validates the effectiveness of reranking for context optimization and reveals a nonlinear relationship between retrieval performance gains and downstream answer improvements.

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Counterfactual Auditing of Bias in Open-Source Large Language Models for Clinical Triage

Oct 01, 2026

This study addresses the vulnerability of open-source large language models to counterfactual biases driven by non-clinical factors in pediatric emergency triage, which threatens decision fairness. To investigate this, we construct paired counterfactual cases altering only demographic or social variables to audit the sensitivity of Emergency Severity Index predictions across ten open-source models. We propose a lightweight, interpretable framework incorporating hierarchical correlation analysis, evaluated alongside QLoRA fine-tuning and medical-specific models such as MedGemma. Our findings reveal that scaling model size or employing medical pretraining does not necessarily mitigate bias, uncovering latent directional failure modes. Notably, the fine-tuned Qwen2.5-7B achieves the lowest bias rate at 5.27%. This work provides empirical evidence and methodological support for conducting fairness audits prior to clinical deployment.

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Recent publications

Latest Papers

Fed-ADApt: Federated Anytime Depth Adaptation for Resource-Aware Medical Image Segmentation

Oct 02, 2026

This study addresses the challenge of computational heterogeneity in federated medical image segmentation, which often restricts the participation of resource-constrained institutions. To this end, we propose a deep adaptive federated learning framework built upon a UNet architecture that incorporates multi-depth supervision and hierarchical aggregation mechanisms. This design enables participating nodes to dynamically select training and inference depths according to their local computational budgets, thereby achieving joint optimization of resource allocation. Experimental results demonstrate that the proposed framework attains performance comparable to full-capacity models on 3D segmentation tasks while substantially reducing both training and inference overhead. By facilitating equitable and efficient collaboration across heterogeneous environments, this approach effectively empowers low-resource institutions to participate in federated medical analysis.

0 citationsRead paper

Evaluating Biomedical Reranking for LLM-Based Question Answering over Longitudinal Clinical Notes

Oct 01, 2026

This study addresses the challenge of degraded patient question-answering quality caused by fragmented evidence and heterogeneous terminology in longitudinal clinical records by constructing a localized retrieval-augmented generation (RAG) pipeline. Methodologically, it integrates PubMedBERT-based dense retrieval with BM25 lexical retrieval via weighted reciprocal rank fusion, and incorporates a MedCPT cross-encoder for biomedical reranking to optimize evidence selection. Results demonstrate that the top-10 retrieval hit rate increases from 46.6% to 60.6%, while the answer accuracy of Qwen3-8B improves from 44.8% to 48.6%. This work validates the effectiveness of reranking for context optimization and reveals a nonlinear relationship between retrieval performance gains and downstream answer improvements.

0 citationsRead paper

Counterfactual Auditing of Bias in Open-Source Large Language Models for Clinical Triage

Oct 01, 2026

This study addresses the vulnerability of open-source large language models to counterfactual biases driven by non-clinical factors in pediatric emergency triage, which threatens decision fairness. To investigate this, we construct paired counterfactual cases altering only demographic or social variables to audit the sensitivity of Emergency Severity Index predictions across ten open-source models. We propose a lightweight, interpretable framework incorporating hierarchical correlation analysis, evaluated alongside QLoRA fine-tuning and medical-specific models such as MedGemma. Our findings reveal that scaling model size or employing medical pretraining does not necessarily mitigate bias, uncovering latent directional failure modes. Notably, the fine-tuned Qwen2.5-7B achieves the lowest bias rate at 5.27%. This work provides empirical evidence and methodological support for conducting fairness audits prior to clinical deployment.

0 citationsRead paper