Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: koło tętnicze Willisa

Sortuj według:

Ogranicz wyniki do:

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

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

Biocybernetics and Biomedical Engineering

2018

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.

Experimental and numerical modelling of flow in the human cerebral arteries

Cieślicki K.

Journal of Medical Informatics & Technologies

2004

Vol. 7

IP17--26

The paper presents the results of experiments concerning flow in the model of cerebral supplying arteries and the Circle of Willis (CW). Vascular phantom was prepared on the basis of anatomical specimens. The most typical artery shapes and dimensions were considered. Pressure distribution in 6 characteristic points is provided, and so are the average flow rates in the anterior, middle and posterior section of the brain. Tests were run in the conditions replicating the physiological state (i.e. when the supplying arteries were fully patent) and in pathological conditions, in which the internal carotid and vertebral arteries were occluded on one or both sides. Thus obtained results were compared with the results of computer simulations based on linear and non-linear flow models. To estimate the non-linear resistance of vascular segment two phenomenological formulae were proposed. High degree of correlation between the values obtained from experiments and those registered in non-linear computer model proves usefulness of proposed formulae. It verifies the hypothesis that nonlinearity of flow characteristics of the vessel segments is to a great extent caused by their tortuous and small length in relation to diameter. Non-linear effects are particularly pronounced in conditions of pathological occlusion of supplying vessels.