Editors' Preface to Data Fusion Techniques and Applications for Smart Healthcare 1. Retinopathy Screening from OCT Imagery via Deep Learning 2. Multi-sensor data fusion in digital twins for smart healthcare 3. Deep Learning for Multi-source Medical Information Processing 4. Robust watermarking algorithm based on multimodal medical image fusion 5. Fusion based Robust and Secure Watermarking Method for e-Healthcare Applications 6. Recent Advancements in Deep Learning-based Remote Photoplethysmography Methods 7. Federated Learning in Healthcare Applications 8. Riemannian Deep Feature Fusion with auto-encoders for MEG Depression Classification in Smart Healthcare applications 9. Epileptic Spike Localization using MEG MRI modality Fusion for Intelligent Smart Healthcare 10. Early classification of time series data: Overview, Challenges, and Opportunities 11. Deep Learning based multimodal medical image fusion 12. Data fusion in internet of medical things: Towards trust management, security and privacy 13. Feature fusion for medical data 14. Review on Hybrid Feature Selection and Classification of Microarray Gene Expression Data 15. MFFWmark: Multi focused fusion based image watermarking for telemedicine applications with BRISK feature authentication 16. Distributed Information Fusion for Secured Healthcare 17. Deep Learning for Emotion Recognition using Physiological Signals