The proposed system introduces a multi-frequency electromagnetic wave analysis method for non invasive monitoring the volume of urine in the bladder. The innovation of the proposed system according to the present invention provides means for analyzing signal information received, after propagation via the bladder, by applying a pre-defined prediction function (resulting from the application of learning algorithm in conjunction with a Feature Extraction, algorithm for calculating the most contributing electromagnetic wavelengths, determining the most accurate measurements), and providing an accurate estimation of the volume of urine in the bladder.