Numerical analysis of an influence of the artificial valve type on the blood flow inside the ventricular assist device

Przemyslaw Klosinski, Piotr Reorowicz, Damian Obidowski, Krzysztof Jozwik

Technical University of Lodz, Institute of Turbomachinery,,Medical Apparatus Division, Lodz, Poland.

DOI:

https://doi.org/10.7494/cmms.2011.1.0336

Abstract:

A Ventricular Assist Device (VAD) is used in case of severe heart illnesses when the natural heart supplies the body with an insufficient volume of blood. Any damage or improper functioning of the VAD can result in the patient’s death. This implies the constant need to improve the design of VADs and artificial valves which are crucial parts of the device. The authors used the latest Computer Aided Design and Computational Fluid Dynamics software to analyze the flow in the pneumatic Ventricular Assist Device designed at the Foundation of Cardiac Surgery Development and equipped with two different types of valves. In the study, a single-disc mechanical artificial heart valve based on the invention of Prof. J.J. Moll, modified at the Institute of Turbomachinery, TU Lodz, was compared with a three-leaflet polyurethane artificial heart. A comparison was made on the basis of the flow visualization inside the VAD chamber and the size of stagnation regions where the flowing blood may coagulate. An angular position of the disc valve was determined on the basis of the previous studies. A steady state simulation was performed on the assumption that walls of the assist device, adapters and valves were rigid. Dynamic viscosity of blood was defined on the basis on the Non-Newtonian Power Law. Simulations were preformed for systole and diastole conditions. The Ansys CFX v12 code was used to perform preprocessing, solving and postprocessing stages. Deformations of the three-leaflet polyurethane valve were obtained in SolidWorks 2009 and imported to Ansys ICEM v.12. On the basis of the preformed analysis, it has been proven that the disc mechanical heart valve generates better flow conditions inside the heart chamber, especially if a risk of coagulation is concerned. Moreover, the flow observed inside the chamber when the disc valve was used is more homogenous and a single swirl occurring in the central part enables good washing of the connection of the diaphragm and chamber regions.

Cite as:

Klosinski, P., Reorowicz, P., Obidowski, D., & Jozwik, K. (2011). Numerical analysis of an influence of the artificial valve type on the blood flow inside the ventricular assist device. Computer Methods in Materials Science, 11(1), 209 – 214. https://doi.org/10.7494/cmms.2011.1.0336

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