The fuzzy-based multifractal theory for signals is developed in order to define Fuzzy Generalized Fractal Dimensions by introducing the fuzzy membership function in the classical GFD method, and it is used for the classification of chaotic behaviors in the fractal waveforms. In this chapter, we have also proposed a fuzzy multifractal measure for biomedical signals to identify the age-group of subjects. The proposed method discriminates the young and elderly subjects by applying Fuzzy Generalized Fractal Dimensions with the Gaussian fuzzy membership function in ECG Signals through the cardiac inter-heartbeat time interval dynamics. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.