1. Saratov Branch of the Institute of Radio Engineering and Electronics of Russian Academy of Sciences, Zelyonaya Street, 38, Saratov 410019, Russia
2. Department of Innovative Cardiological Information Technology, Institute of Cardiological Research, Saratov State Medical University, B. Kazachaya Street, 112, Saratov 410012, Russia
3. Department of Dynamic Modeling and Biomedical Engineering, Saratov State University, Astrakhanskaya Street, 83, Saratov 410012, Russia