Tran Trong Huu - Post-graduate Student, Department of Biotechnical Systems, Saint Petersburg Electrotechnical University «LETI» E-mail: tronghuu@mail.ru E.V. Sadykova - Ph.D. (Eng.), Associate Professor, Department of Biotechnical Systems, Saint Petersburg Electrotechnical University «LETI» E-mail: elensadykova@yandex.ru