Mathematical Modeling of Rhytmocardiografic Signals Spectrum

The most informative indicators of heart rate variability (HRV) are spectral indices, however, their evaluations are irreproducible and ambiguous. To standardize the procedure for calculation of HRV indices´ evaluations (and especially the functions of the spectral power density - SPD), mathematical software was developed to form a reference simulated rate cardiographic (RCG) signal, and to generate a series of such signals with a random spread of certain parameters in order to produce an array of reference signals. The multitude of the examined RCG signal models included the following: A set of sine curves, a model of an integral pulse-frequency modulator, finally, a model of the signal spectrum in the frequency domain, with further transformation into the time domain and creation of a time series of RCG values.