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Angular position determination of heart valves in the pediatric ventricular assist device with use of computational fluid dynamics

100%

Jodko D. , Obidowski D. , Reorowicz P. , Kłosiński P. , Jóźwik K.

tom z. 8

57--62

This study shows a method than can be used to determine the best angular position of heart valves installed at the inlet and the outlet of a blood chamber during the diastolic phase with use of Computational Fluid Dynamics (CFD). Steady state simulations of the blood flow through the blood chamber of Pediatric Ventricular Assist Device (PVAD) have been performed with ANSYS CFX 14.0. Main assumptions in the present paper have included: motionless discs, rigid walls, non-Newtonian model of blood. The obtained results show that areas of blood stagnation in the blood chamber are smallest for one particular angular position of the inlet valve and are not significantly dependent on the angular position of the outlet valve.

Numerical simulations of the pulsatile blood flow in the different types of arterial fenestrations: Comparable analysis of multiple vascular geometries

86%

Tyfa Z. , Obidowski D. , Reorowicz P. , Stefańczyk L. , Fortuniak J. , Jóźwik K.

tom Vol. 38, no. 2

228--242

In medical terms, fenestration stands for an anomaly within the circulatory system in which the blood vessel lumen is divided into two separate channels that rejoin in the distal part of this vessel. The primary objective of this research was to analyze the impact of the left vertebral artery (LVA) and basilar artery (BA) fenestrations on the blood flow characteristics in their regions and downstream, in the cerebral circulation. The geometrical data, obtained from the angio-Computed Tomography, were the basis for the generation of a 3D model in SolidWorks 2015. In order to observe the flow characteristics within the whole spatial domain, computational fluid dynamics was involved in performing simulations of the blood flow in the patient-specific arterial system (beginning with the aortic arch and finishing with the Circle of Willis). To examine the flow distribution changes resulting from altered fenestration geometries, additional models were built. The blood flow velocity, volume flow rate and shear stress distribution were analyzed within this study. It was proven that the length/size/ position of the fenestration altered the flow characteristics in different manners. The investigations showed that the patient-specific LVA, at the V3 section (extracranial part of the artery located between the spine and the skull), is not a reason of aneurysm formation. However, BA fenestration at the proximal segment might be a possible reason of future aneurysm formation. It was proven that the computational fluid dynamics tool could support medical diagnostic procedures and multivessel brain vascular disease treatment planning.