Аннотация:The functional tomography method, based on the spectral analysis of multichannel time series oflong duration, has been used to study the distribution of electrical sources in the human body. The spontaneous activity of various organs and tissues has been studied. The spatial distribution and directions of elementary sources of alpha rhythm in the brain have been examined. Spontaneous brain activity has been studied in mental disorders. Using a cardiogram, the functional structure of the heart has been found, and using myography data, working skeletal muscles have been reconstructed. The spatial distribution of moving magnetic nanoparticles was also found. The coincidence of the results with the anatomical and physical structure of the complex systems being studied confirms the high promise of the proposed method in various fundamental and applied problems.