SVERSTIUK, A. and MOSIY, L. 2025. MATHEMATICAL MODEL OF EXTREMA VARIATIONS IN CHARACTERISTIC WAVES OF ELECTROCARDIOGRAPHIC SIGNALS BASED ON A DISCRETE FUNCTION OF  AMPLITUDE VARIABILITY. Herald of Khmelnytskyi National University. Technical sciences. 355, 4 (Aug. 2025), 404–413. DOI:https://doi.org/10.31891/2307-5732-2025-355-57.