CATransformer: A Cycle-Aware Transformer for High-Fidelity ECG Generation From PPG - Yuan, X.; Wang, W.; Li, X.; Zhang, Y.; Hu, X.; Deen, M.J. (IEEE Journal of Biomedical and Health Informatics, Biomedical and Health Informatics, IEEE Journal of, IEEE J. Biomed. Health Inform., 2026)