Numerical Investigation for the Effect of Blood Flow Rate and Asymmetric Bifurcation Angle on the Anterior Circulation Aneurysm Formation

2011 ◽  
Author(s):  
Soyoon Kim ◽  
Kyoungchul Ro ◽  
Hong Sun Ryou
Keyword(s):  
High Pressure ◽  
Blood Flow ◽  
Blood Vessel ◽  
Flow Rate ◽  
Rate Ratio ◽  
Arterial Wall ◽  
Blood Flow Rate ◽  
Flow Rate Ratio ◽  
Anterior Circulation ◽  
Bifurcation Angle

Most of aneurysms in the cranial cavity occur at the bifurcation of anterior circulation system. A cerebral aneurysm is easily ruptured, and it is fatal for most patients. Generally it is known that aneurysm occurs when arterial wall is deformed by high pressure or high wall shear stress (WSS). A blood flow pattern and the geometry and the blood vessel are important factors for aneurysm formation and the location. The transient interaction between blood flow and the arterial wall affects for simulating deformation of the blood vessel. Thus, numerical analysis is performed for various bifurcation angles and flow rate ratio in bifurcation artery with different diameters to predict the location of aneurysm by hemodynamic characteristics of blood flow. A bifurcation angle between the internal carotid artery and the anterior cerebral artery (ACA) increased, a region of high pressure moved to the bifurcated artery with larger bifurcation angle when ratio of blood flow rate is constant case. When the ratio of blood flow increased, the region of high wall shear stress moved to the side of large flow rate ratio. Our results showed that the high WSS or high pressure region occur at the location of aneurysm as mentioned in the clinical research. Thus, this indicates that the geometry of blood vessel and blood flow rate affect the location of the anterior circulation aneurysm.

Effective Ionic Dialysance/Blood Flow Rate Ratio: An Indicator of Access Recirculation in Arteriovenous Fistulae

ASAIO Journal ◽  
2010 ◽  
Vol 56 (5) ◽  
pp. 427-433 ◽  
Author(s):  
Sumit Mohan ◽  
Machaiah Madhrira ◽  
Muhammad Mujtaba ◽  
Rajesh Agarwala ◽  
Velvie Pogue ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Rate Ratio ◽  
Blood Flow Rate ◽  
Flow Rate Ratio ◽  
Arteriovenous Fistulae

Is the Maturation of Arteriovenous Fistulas a Mechanical or Biological Problem?

2016 ◽  
Author(s):  
Daniel Jodko ◽  
Damian Obidowski ◽  
Piotr Reorowicz ◽  
Krzysztof Jozwik
Keyword(s):  
High Pressure ◽  
Blood Flow ◽  
Shear Stress ◽  
Flow Rate ◽  
Blood Flow Rate ◽  
Average Diameter ◽  
Patient Specific ◽  
Maturation Process ◽  
Arteriovenous Fistulas ◽  
Biological Problem

During the maturation the high pressure blood from the artery inflows directly to the vein, extends its diameter, and finally the blood flow rate in the vein is even 500-times greater than normal one. The changes of the wall shear stress (WSS) in the vein are thought to play a key role in the remodelling of its wall. However, this process is still not well understood. The aim of this paper is to show an innovative approach for modelling of the vein deformation during the maturation process of a-v fistulas. Dilation of the vein was modelled as two-step complex biomechanical process. The obtained results concerning final diameter of the vein are compared with average diameter obtained for large group of patients. Moreover, this study shows the changes in the flow rate and the WSS that occur after maturation in the patient-specific fistula.

scholarly journals Application of Non-thermal Commscope Irradiation in Preventing Com- plications of Hemodialysis Fistula

1970 ◽  
Vol 1 (1) ◽  
Author(s):  
Leng Hui
Keyword(s):  
Blood Flow ◽  
Blood Vessel ◽  
Arteriovenous Fistula ◽  
Flow Rate ◽  
Blood Flow Rate ◽  
Hemodialysis Patients ◽  
First Choice ◽  
Long Time ◽  
And Control

Abstract: Objective: To ensure that the patient’s treatment and control of the patient’s blood in the course of long-term dialysis, in order to ensure the blood flow rate at the rate of hemodialysis in the blood vessel of hemodialysis patients, mortality rate. Methods: In many Western countries, it has been found from the experience of long-term accumulation, arteriovenous fistula (AVF) is the first choice for long-term dialysis blood patients, which has a lot of a little bit, not only from the infection rate and blood flow, which has a lot of advantages.But its existence is also a lot of complications, non-thermal Commscope irradiation is a very effective way. Results: The method was compared with the method, and it was found that P <0.05, which was statistically significant. Conclusion: AVF is the preferred method of vascular access in patients with persistent dialysis, which is very easy to be punctured and has a very long time for maintenance. It is very important to carry out the treatment, treatment and surveillance of AVF complications and the use of means.

Determination of flow rate ratio for plate valve operating in two-phase medium

1989 ◽  
Vol 25 (7) ◽  
pp. 394-396
Author(s):  
V. E. Shcherba ◽  
I. S. Berezin ◽  
S. S. Danilenko ◽  
I. E. Titov ◽  
P. P. Filippov
Keyword(s):  
Flow Rate ◽  
Rate Ratio ◽  
Flow Rate Ratio ◽  
Two Phase ◽  
Plate Valve ◽  
Phase Medium

The Effect of Furosemide on the Intrarenal Blood Flow Distribution in the Dog

1972 ◽  
Vol 50 (8) ◽  
pp. 774-783 ◽  
Author(s):  
Serge Carrière ◽  
Michel Desrosiers ◽  
Jacques Friborg ◽  
Michèle Gagnan Brunette
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Urine Volume ◽  
Flow Distribution ◽  
Blood Flow Rate ◽  
Initial Distribution ◽  
Blood Flow Distribution ◽  
Intrarenal Blood Flow ◽  
Femoral Blood ◽  
Furosemide Administration

Furosemide (40 μg/min) was perfused directly into the renal artery of dogs in whom the femoral blood pressure was reduced (80 mm Hg) by aortic clamping above the renal arteries. This maneuver, which does not influence the intrarenal blood flow distribution, produced significant decreases of the urine volume, natriuresis, Ccreat, and CPAH, and prevented the marked diuresis normally produced by furosemide. Therefore the chances that systemic physiological changes occurred, secondary to large fluid movements, were minimized. In those conditions, however, furosemide produced a significant increase of the urine output and sodium excretion in the experimental kidney whereas Ccreat and CPAH were not affected. The outer cortical blood flow rate (ml/100 g-min) was modified neither by aortic constriction (562 ± 68 versus 569 ± 83) nor by the subsequent administration of furosemide (424 ± 70). The blood flow rate of the outer medulla in these three conditions remained unchanged (147 ± 52 versus 171 ± 44 versus 159 ± 54). The initial distribution of the radioactivity in each compartment remained comparable in the three conditions. In parallel with the results from the krypton-85 disappearance curves, the autoradiograms, silicone rubber casts, and EPAH did not suggest any change in the renal blood flow distribution secondary to furosemide administration.

The Effect of Hematocrit on the Clearance of Small Molecules during Hemodialysis

1983 ◽  
Vol 6 (3) ◽  
pp. 127-130 ◽  
Author(s):  
C. Woffindin ◽  
N.A. Hoenich ◽  
D.N.S. Kerr
Keyword(s):  
Blood Flow ◽  
Regression Analysis ◽  
Small Molecules ◽  
Flat Plate ◽  
Flow Rate ◽  
Distribution Curve ◽  
Blood Flow Rate ◽  
Hollow Fibre ◽  
Urea Clearance ◽  
Flow Rates

Data collected during the evaluation of a series of hemodialysers were analysed to see the effect of hematocrit on the clearance of urea and creatinine. All evaluations were performed on patients with a range of hematocrits with a mean close to 20%. The urea clearance of those in the upper half of the distribution curve (mean hematocrit 29.4%) was not significantly different from that of patients in the lower half of the distribution curve (mean hematocrit 16.9%) whether the clearance was studied at high or low blood flow rates and with hollow fibre or flat plate disposable hemodialysers. Likewise, there was no correlation between hematocrit and urea clearance by regression analysis. In contrast, the clearance of creatinine was affected by hematocrit being greater at lower hematocrit values. This difference was independent of blood flow rate and dialyser type and was confirmed by regression analysis.

Effect of the argon/monomer flow-rate ratio on the flowability trend of PECVD-processed micropowder

2017 ◽  
Vol 328 ◽  
pp. 480-487 ◽  
Author(s):  
V.R. Giampietro ◽  
M. Gulas ◽  
P. Rudolf von Rohr
Keyword(s):  
Flow Rate ◽  
Rate Ratio ◽  
Flow Rate Ratio
Sign in / Sign up

Export Citation Format

Share Document