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Introduction.One of the main indicators characterizing mechanical circulatory support devices (artificial valve, implantable pumps, etc.) is trauma of blood cells. Therefore, while developing new pumps, one of the key studies in vitro is to evaluate blood hemolysis. For an objective hemolysis analysis of pump it is required to create a standardized methodology of hemolysis studies. The object of the study in this paper is implantable axial pump DON for two-step heart transplantation in children.The aimof study is to develop a standardized methodology of hemolysis studies of blood pumps and to conduct research of pediatric axial pump DON.Materials and methods.To conduct hemolysis research we created a mock circulatory system consisting of a reservoir placed in water bath maintaining a constant working fluid (blood) temperature, hydrodynamic resistance, connecting tubes, ports for blood sampling and pressure and flow measurement systems, and research pump. Test method is to estimate levels of free hemoglobin pHb obtained by blood samples during pump working in operating mode (for pediatric pump: blood flow 2.5 l/min, pressure difference 80 mmHg). Using the data obtained the standardized indices of hemolysis NIH and MIH are calculated based on pHb values, hematocrit, total hemoglobin, blood flow and working pump time.Results.We developed and realized a standardized methodology of hemolysis research by which we evaluated hemolysis of pediatric axial pump. The results of hemolysis tests allowed us to optimize the design of DON. Obtained values of hemolysis of the latest version of pediatric pump DON-3 have shown that they do conform to the requirements of minimum blood injury and it allows us to proceed to the next step of pediatric pump research – animal experiments.Conclusion.Developed methods and evaluation tools of hemolysis allow us to provide objective information on one of the most important indicators of developing implantable pediatric axial pump and they could be recommended for hemolysis research of others pumps.

Aim.To evaluate the functioning of an implantable pediatric axial pump «DON-3» for bypassing the left ventricle of the heart in experiments on sheep.Materials and methods. Five sheeps at the age of 12–18 months performed paracorporeal installation of the children’s axial pump «DON-3» according to the scheme «left ventricle – aorta».Results.A technique was developed and 5 chronic experiments were conducted on sheep to assess the model of the children’s axial pump «DON-3». The duration of the experiments in this series averaged 9 ± 5 days. The main indicators of hemodynamics, acid-base balance were within the norm. Conducted morphological and histological studies of the kidneys, liver and lungs did not reveal the presence of zones of ischemia and thromboembolism.Conclusion.The results of this series of experiments showed satisfactory results, suggesting further research on the development of prototypes of a pediatric pump for clinical practice.

The use of extracorporeal circulation systems (cardiopulmonary bypass pumps, ECMO) can lead to brain and coronary artery microembolism, which significantly reduces postoperative rehabilitation and often leads to severe complications. Microembolism occurs when oxygen or air microbubbles (MBs) enter the arterial system of patients. Existing CPB pumps come with built-in bubble trap systems but cannot remove bubbles in the circuit. ECMO devices have arterial filters but cannot reliably filter out <40 μm bubbles in a wide flow range. We have proposed an alternative method that involves the use of an efficient dynamic bubble trap (DBT) for both large and small bubbles. The design includes development of two DBT variants for hemodynamic conditions of adult and pediatric patients. The device is installed in the CPB pump and ECMO outlet lines. It provides sufficient bubble separation from the lines in a blood flow of 3.0–5.0 L/min for adults and 0.5–2.0 L/min for children. The developed computer models have shown that MBs smaller than 10 μm can be filtered. The use of this device will greatly reduce the likelihood of air embolism and provide the opportunity to reconsider the concept of expensive arterial filters.

Aim: to develop a new modified index for the assessment of bioenergy heart in conditions of heart failure. To assess the energy of the heart when using systems to bypass the left ventricle of the heart using non-pulsed flow pumps. To consider the fundamental advantage of non-pulsating flow pumps with the generation of a pulsating flow in the cardio-synchronized copulsation mode over the counterpulsation mode.