Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "artery model" wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
Comparison of experimental results and numerical calculations of ultrasonic waves scattering on a model of the artery
Autorzy:
Wójcik, J.
Trawiński, Z.
Powałowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/331649.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
ultrasonic waves
artery model
transmitted ultrasound
Opis:
The aim of this paper is to compare the results of the mathematical modeling and experimental results of the ultrasonic waves scattering in the inhomogeneous dissipative medium. The research was carried out for an artery model (a pipe made of a latex), with internal diameter of 3, 5 and 8 mm and wall thickness of 0.75, 1.25 and 2 mm. The numerical solver was created for calculation of the fields of ultrasonic beams and scattered fields under different boundary conditions, different angles and transversal displacement of ultrasonic beams with respect to the position of the arterial wall. The investigations employed the VED ultrasonic apparatus. The frequency of the transmitted ultrasound was 6.75 MHz. The good agreement between the numerical calculation and experimental results was obtained. The numerical solver is used for verified proposed methods for determining of the IMT in the artery walls.
Źródło:
Hydroacoustics; 2008, 11; 449-458
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-point Method for Arterial Local Pulse Wave Velocity Measurement by Means of Ultrasonic RF Signal Processing
Autorzy:
Trawiński, Z.
Powiązania:
https://bibliotekanauki.pl/articles/178000.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasound
local pulse wave velocity
model of artery
Opis:
The aim of this paper is to describe a non-invasive method of examination of the local pulse wave velocity. The measurements were carried out in the model of the artery immersed in a water tank. Two synchronized ultrasonic apparatus VED with the ultrasonic radio frequency echoes acquisition system were used for evaluation of the arterial elasticity. The zero-crossing method was used for determination of the diameter changes of the artery model. The transit time between the waveforms of instant artery diameter was measured at two points of the artery model, separated by the distance of 5 cm. The transit time was determined using the criteria of similarity of the first derivatives of the raising slopes of the curves describing instant vessel’s diameter changes. The pulse wave velocity obtained by the proposed twopoint method was compared with the results obtained by the one-point method based on the modified Bramwell–Hill relation.
Źródło:
Archives of Acoustics; 2010, 35, 1; 3-11
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical guidelines on the properties of human healthy arteries in the design and fabrication of vascular grafts: experimental tests and quasi-linear viscoelastic model
Autorzy:
Faturechi, Rahim
Hashemi, Ata
Abolfathi, Nabiollah
Solouk, Atefeh
Powiązania:
https://bibliotekanauki.pl/articles/307007.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
elastyczność
model konstytutywny
tętnica
elasticity
constitutive model
human artery
artificial artery
quasi-linear viscoelasticity
Opis:
Knowledge of mechanical behavior of healthy human arteries as the guidelines to target properties of vascular grafts deserves special attention. There is a lack of mathematical model to characterize mechanical behavior of biomaterial while many mathematical models to reflect mechanics of human arteries have been proposed. The objective of this paper was set to measure mechanical properties of healthy human arteries including Common Carotid Artery (CCA), Abdominal Aorta Artery (AAA), Subclavian Artery (SA), Common Iliac Artery (CIA) and Right and Left Iliac Artery (RIA and LIA) and compare them to those of commercial ePTFE and Dacron®. Methods: Series of stress relaxation and strain to failure tests vere performed on all samples. The experimental data was utilized to develop quasi-linear viscoelastic (QLV) model of both natural and artificial arteries. Results: ePTFE is the stiffest sample, while the CCA is the most compliant one among all. RIA and CIA are more viscous than the other natural arteries, while AA and CCA are less viscous. The proposed model demonstrated an accurate fit to the experimental results, a proof of its ability to model both nonlinear elasticity and viscoelasticity of the human arteries and commercial ones. Conclusions: ePTFE and Dacron® are much stiffer than human arteries that may lead to the disruption of blood hemodynamic and may not be biomechanically feasible as a replacement.
Źródło:
Acta of Bioengineering and Biomechanics; 2019, 21, 3; 13-21
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of blood flow rheology using second-grade viscoelastic model (Phan-Thien–Tanner) within carotid artery
Autorzy:
Ramiar, A.
Larimi, M. M.
Ranjbar, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/307522.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
tętnica szyjna
model lepkoplastyczny
przepływ pulsujący
naprężenie ścinające
OpenFOAM
carotid artery
viscoelastic model
pulsatile flow
shear stress
Opis:
Purpose: Hemodynamic factors, such as Wall Shear Stress (WSS), play a substantial role in arterial diseases. In the larger arteries, such as the carotid artery, interaction between the vessel wall and blood flow affects the distribution of hemodynamic factors. The fluid is considered to be non-Newtonian, whose flow is governed by the equation of a second-grade viscoelastic fluid and the effects of viscoelastic on blood flow in carotid artery is investigated. Methods: Pulsatile flow studies were carried out in a 3D model of carotid artery. The governing equations were solved using finite volume C++ based on open source code, OpenFOAM. To describe blood flow, conservation of mass and momentum, a constitutive relation of simplified Phan-Thien–Tanner (sPTT), and appropriate relations were used to explain shear thinning behavior. Results: The first recirculation was observed at t = 0.2 s, in deceleration phase. In the acceleration phase from t = 0.3 s to t = 0.5 s, vortex and recirculation sizes in bulb regions in both ECA and ICA gradually increased. As is observed in the line graphs based on extracted data from ICA, at t = 0.2 s, τyy is the maximum amount of wall shear stress and τxy the minimum one. The maximum shear stress occurred in the inner side of the main branch (inner side of ICA and ECA) because the velocity of blood flow in the inner side of the bulb region was maximum due to the created recirculation zone in the opposite side in this area. Conclusions: The rheology of blood flow and shear stress in various important parts (the area that are in higher rates of WSS such as bifurcation region and the regions after bulb areas in both branches, Line1–4 in Fig. 7) were also analyzed. The investigation of velocity stream line, velocity profile and shear stress in various sections of carotid artery showed that the maximum shear stress occurred in acceleration phase and in the bifurcation region between ECA and ICA which is due to velocity gradients and changes in thinning behavior of blood and increasing strain rate in Newtonian stress part.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 3; 27-41
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies