The Progress in the Novel Pediatric Rotary Blood Pump Sputnik Development Dmitry Telyshev , Maxim Denisov, Alexander Pugovkin, Sergey Selishchev, and Igor Nesterenko National Research University of Electronic Technology, Biomedical Systems Department, Zelenograd, Moscow, Russia Abstract: In this work, the study results of an implant- able pediatric rotary blood pump (PRBP) are presented. They show the results of the numerical simulation of fluid flow rates in the pump. The determination method of the backflows and stagnation regions is represented. The operating points corresponding to fluid flow rates of 1, 3, and 5 L/min for 75–80 mm Hg pressure head are investigated. The study results have shown that use of the pump in the 1 L/min operating point can potentially lead to the appearance of backflows and stagnation regions. In the case of using pumps in fluid flow rates ranging from 3 to 5 L/min, the number of stagnation regions decreases and the fluid flow rate changes margin- ally. Using the pump in this flow rate range is considered judicious. The study shows an increase in shear stress with an increase in fluid flow rates, while there is no increase in shear stress above the critical condition of 150 Pa (which does not allow us to reliably speak about the increased risk of blood cell damage). The aim of this work was to design, prototype, and study interaction of the Sputnik PRBP with the cardiovascular system. A three-dimensional model of Sputnik PRBP was designed with the following geometrical specifications: flow unit length of 51.5 mm, flow unit diameter of 10 mm, and spacing between the rotor and housing of 0.1 mm. Com- putational fluid dynamics studies were used to calculate head pressure-flow rate (H-Q) curves at rotor speeds ranging from 10 000 to 14 000 rpm (R 2 5 0.866 between numerical simulation and experiment) and comparing flow patterns at various points of the flow rate operating range (1, 3, and 5 L/min) for operating pressures ranging from 75 to 80 mm Hg. It is noted that when fluid flow rate changes from 1 L/min to 3 L/min, significant changes are observed in the distribution of zero flow zones. At the inlet and outlet of the pump, when going to the oper- ating point of 3 L/min, zones of stagnation become minuscule. The shear stress distribution was calculated along the pump volume. The volume in which shear stress exceed 150 Pa is less than 0.38% of the total pump volume at flow rates of 1, 3, and 5 L/min. In this study, a mock circulatory system (MCS) allowing simulation of physiological cardiovascular characteristics was used to investigate the interaction of the Sputnik PRBP with the cardiovascular system. MCS allows reproducing the Frank-Starling autoregulation mechanism of the heart. PRBP behavior was tested in the speed range of 6 000 to 15 000 rpm. Decreased contractility can be expressed in a stroke volume decrease approximately from 18 to 4 mL and ventricle systolic pressure decrease approximately from 92 to 20 mm Hg. The left ventricle becomes fully supported at a pump speed of 10 000 rpm. At a pump speed of 14 000 rpm, the left ventricle goes into a suction state in which fluid almost does not accumulate in the ventricle and only passes through it to the pump. The proposed PRBP showed potential for improved clinical outcomes in pediatric patients with a body surface area greater than 0.6 m 2 and weight greater than 12 kg. Key Words: Congestive heart failure—Mechanical circulatory support—Mock circulatory loop—Pediatric rotary blood pump. About 8 million people in Russia suffer from heart failure (HF). Approximately 30% of them (nearly 2.5 million people) have acute HF (classes III and IV of the New York Heart Association classification of HF). Acute HF is the most wide- spread reason for hospitalization and death from heart diseases (1). doi: 10.1111/aor.13109 Received July 2017; revised November 2017; accepted December 2017. Address correspondence and reprint requests to Dmitry Tely- shev, National Research University of Electronic Technology Biomedical Systems Department, Zelenograd, Moscow 124635, Russia. E-mail: telyshev@bms.zone Presented in part at the 13th International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion held September 28-30, 2017 in Rome, Italy. Artificial Organs 2018, 42(4):432–443 Copyright V C 2018 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.