FIELD: medicine. SUBSTANCE: method involves detecting RR interval and carrying out spectral analysis of its envelope noted for its sample having minimum of 360 degrees RR intervals and the spectrum is built in logarithmic scale of frequencies. Spectral density minima are determined to detect the heart, lung, vascular and metabolic systems. The peak zone for each of the systems is determined using not less than 50 points. Information quantity characteristic is calculated which is needed to organize the selected spectrum. Information quantity is determinable from a formula, cited in the patent application. The level of information quantity is to be used for evaluating the state of feedback of regulation processes. EFFECT: enhanced accuracy in determining the state of regulation processes in human body organism functional systems. 3 dwg, 1 tbl
