Acute kidney injury (AKI) is a common and serious condition in critical care, making early prediction essential for timely intervention, reduced mortality, and lower healthcare costs. Machine learning methods using electronic health records have shown promise in identifying at-risk patients, but their performance is often limited by reliance on single-institution datasets and poor generalizability across populations. Privacy regulations such as HIPAA and GDPR further restrict cross-hospital data sharing, hindering the development of more robust models.To address these challenges, this study proposes a federated learning–based framework for AKI prediction, enabling multiple hospitals to collaboratively train models without exchanging raw patient data. Each institution acts as a local client that trains on its own data and shares only model updates, which are aggregated into a global model. The framework incorporates standardized feature processing, secure aggregation, and communication-efficient strategies to ensure scalability across heterogeneous healthcare environments.This privacy-preserving approach improves model generalization by leveraging diverse multi-institutional data while maintaining regulatory compliance. Although it introduces challenges such as communication overhead and convergence complexity, these are mitigated through optimized aggregation methods. Overall, the proposed framework enhances predictive performance, supports clinical decision-making, and offers a scalable foundation for future privacy-aware healthcare AI systems in AKI management.
Diabetic retinopathy is a leading cause of preventable blindness, with fundus photography commonly used for early detection and severity grading, while deep learning models have shown strong performance in classification but require large, diverse multi-center datasets that are difficult to obtain due to privacy and regulatory restrictions. Because fundus images are protected health information, hospitals cannot share data, resulting in isolated datasets that limit model generalizability across different populations, imaging devices, and clinical settings. To overcome this limitation, a hybrid framework combining federated learning with homomorphic encryption is proposed, allowing multiple hospitals to collaboratively train a shared model without exchanging raw images or plaintext gradients. Each institution performs local training and transmits only encrypted model updates to a central server for secure aggregation, ensuring that patient data remains fully protected while still enabling global model improvement. This approach also mitigates gradient leakage and reconstruction attacks, supports compliance with regulations such as HIPAA and GDPR, and enables scalable, fault-tolerant deployment across heterogeneous healthcare systems, ultimately providing a privacy-preserving pathway for robust multi-center diabetic retinopathy detection.