A Stratified Modeling-Machine Learning Approach to Improve the Accuracy of Non-Invasive Blood Glucose Estimation Using Photoplethysmography Signals. - Fitrilina; Muhammad Ilhamdi Rusydi; Rahmadi Kurnia; Noverika Windasari; Raffi Zahrandhika Putra (Int. J. Online Biomed. Eng., 2025)