Palmieri, Flavio Gomis, Pedro Ruiz, José Esteban Ferreira, Dina Martín-Yebra, Alba Pueyo, Esther Martínez, Juan Pablo Ramírez, Julia Laguna, Pablo ECG-based monitoring of blood potassium concentration: Periodic versus principal component as lead transformation for biomarker robustness Biomed. signal proces. control 10.1016/j.bspc.2021.102719 2021 2021