S.V. Motorina - Post-graduate Student, Department of Biotechnical Systems, Saint Petersburg Electrotechnical University «LETI» E-mail: motorina_sv@mail.ru A.N. Kalinichenko - Dr.Sc. (Eng.), Professor, Department of Biotechnical Systems, Saint Petersburg Electrotechnical University «LETI» E-mail: ank-bs@yandex.ru