scholarly journals Numerical analysis of urine flow through the side holes of a double J stent in a ureteral stenosis

2017 ◽  
Vol 25 ◽  
pp. 63-72 ◽  
Author(s):  
Hyoung-Ho Kim ◽  
Young Ho Choi ◽  
Seung Bae Lee ◽  
Yasutaka Baba ◽  
Kyung-Wuk Kim ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Urine Flow ◽  
Ureteral Stenosis ◽  
Double J Stent ◽  
Flow Through ◽  
Analysis Of Urine

scholarly journals Analysis of Urine Flow in Three Different Ureter Models

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Kyung-Wuk Kim ◽  
Young Ho Choi ◽  
Seung Bae Lee ◽  
Yasutaka Baba ◽  
Hyoung-Ho Kim ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Hydrostatic Pressure ◽  
Flow Rate ◽  
Urine Flow ◽  
Human Anatomy ◽  
Urine Flow Rate ◽  
Ureteral Stenosis ◽  
Double J Stent ◽  
Different Types ◽  
Luminal Flow

The ureter provides a way for urine to flow from the kidney to the bladder. Peristalsis in the ureter partially forces the urine flow, along with hydrostatic pressure. Ureteral diseases and a double J stent, which is commonly inserted in a ureteral stenosis or occlusion, disturb normal peristalsis. Ineffective or no peristalsis could make the contour of the ureter a tube, a funnel, or a combination of the two. In this study, we investigated urine flow in the abnormal situation. We made three different, curved tubular, funnel-shaped, and undulated ureter models that were based on human anatomy. A numerical analysis of the urine flow rate and pattern in the ureter was performed for a combination of the three different ureters, with and without a ureteral stenosis and with four different types of double J stents. The three ureters showed a difference in urine flow rate and pattern. Luminal flow rate was affected by ureter shape. The side holes of a double J stent played a different role in detour, which depended on ureter geometry.

scholarly journals Numerical Analysis of Urine Flow with Multiple Sizes of Double-J Stents

2020 ◽  
Vol 10 (12) ◽  
pp. 4291 ◽  
Author(s):  
Hyoung-Ho Kim ◽  
Kyung-wuk Kim ◽  
Young Ho Choi ◽  
Seung Bae Lee ◽  
Yasutaka Baba
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Rate ◽  
Urine Flow ◽  
Total Flow ◽  
Total Flow Rate ◽  
Flow Rates ◽  
Double J Stent ◽  
Luminal Flow ◽  
Flow Through

This study investigated which sizes of double-J stents are more effective in achieving an acceptable urine flow through stenotic and stented ureters. Sixty four computational fluid dynamics models of the combinations of two different gauge ureters (4.57 mm and 5.39 mm in diameter) with four different levels of ureteral and four different sizes of double-J stents were developed for the numerical analysis of urine flow in the ureter. Luminal, extraluminal, and total flow rates along the ureter were measured, and the flow patterns around the ports and side holes were investigated. For the 4.57-mm ureter, the total flow rate for each gauge of stent was 23–63 mL/h (5 Fr), 20–47 mL/h (6 Fr), 17–35 mL/h (7 Fr), and 16–26 mL/h (8 Fr) and for the 5.39-mm ureter, the total flow rate for each gauge of stent was 43–147 mL/h (5 Fr), 36–116 mL/h (6 Fr), 29–92 mL/h (7 Fr), and 26–71 mL/h (8 Fr). With a 74% stenosis, all stents allowed a low flow rate, and the differences in flow rates between the stents were small. At the other levels of stenosis, 5 Fr stents allowed greater flow rates than the 8 Fr stents. The luminal flow rate increased just before the area of stenosis and decreased after the stenosis because of the increase and decrease in the luminal flow through the side holes before and after the stenosis. Therefore, a larger double-J stent is not favorable in achieving an acceptable urine flow through the stenotic and stented ureters. The results in this study could not be necessarily correlated with clinical situation because peristalsis, viscosity of the urine and real format of the ureter were not considered in our model. In vivo experiments are necessary for confirmation of our findings. Double J stents are commonly used in the ureteral stenosis or occlusion, especially due to ureter stones which obstruct the flow of urine. Clinicians choose the size of double J stent on the basis of their clinical experience. Here, we tried to know which sizes of double J stents are better for sufficient urine flow. According to various documents that try to determine the optimal shape of double J stents to increase the urine flow through the ureter, mostly bigger stent is recommended to occur maximum urine flow. However, in case of ureter with stenosis or occlusion, the right size of the double J stent may vary depending on the degree of stenosis in the ureter. To find appropriate stent size for the ureter with stenosis, computational fluid dynamics was conducted. This study shows that smaller diameter stents are more appropriate than larger diameter stents depending on the situation.

Numerical Analysis of Leakage Flow Through Two Labyrinth Seals

2007 ◽  
Vol 19 (1) ◽  
pp. 107-112 ◽  
Author(s):  
Wei-zhe Wang ◽  
Ying-zheng Liu ◽  
Pu-ning Jiang ◽  
Han-ping Chen
Keyword(s):  
Numerical Analysis ◽  
Leakage Flow ◽  
Labyrinth Seals ◽  
Flow Through

scholarly journals Blood Perfusion of the Kidney of Lophius Piscatorius L.

1953 ◽  
Vol 32 (2) ◽  
pp. 329-336 ◽  
Author(s):  
L. Brull ◽  
E. Nizet ◽  
E. B. Verney
Keyword(s):  
Blood Flow ◽  
Critical Level ◽  
Perfusion Pressure ◽  
Blood Perfusion ◽  
Urine Flow ◽  
The Other ◽  
Protein Nitrogen ◽  
Other Hand ◽  
Flow Through

Lophius kidneys perfused with the heparinized blood (venous) of the fish secrete urine in which total non-protein nitrogen is concentrated, magnesium highly concentrated, and chloride only slightly so or not at all. Oxygenation of the blood, or lowering the temperature of the perfusate from c. 20° to c. 5° C. does not appear to influence secretion. The blood flow through the kidneys increases with the perfusion pressure, the increase often becoming disproportionately large. The urine flow, on the other hand, above a certain critical level is largely independent of changes in perfusion pressure.

Numerical Analysis of Blood Flow Through Artery with Elastic Wall of a Vessel

2016 ◽  
pp. 193-200 ◽  
Author(s):  
Wojciech Wolański ◽  
Bożena Gzik-Zroska ◽  
Kamil Joszko ◽  
Marek Gzik ◽  
Damian Sołtan
Keyword(s):  
Blood Flow ◽  
Numerical Analysis ◽  
Elastic Wall ◽  
Flow Through

Arrangement of side holes in a double J stent for high urine flow in a stented ureter

2020 ◽  
Vol 34 (2) ◽  
pp. 949-954
Author(s):  
Kyung-Wuk Kim ◽  
Hyoung-Ho Kim ◽  
Young Ho Choi ◽  
Seung Bae Lee ◽  
Yasutaka Baba ◽  
...  
Keyword(s):  
Urine Flow ◽  
Double J Stent

scholarly journals Analysis of flow through channel with mounted blades

2018 ◽  
Vol 240 ◽  
pp. 03012
Author(s):  
Łukasz Semkło ◽  
Łukasz Gierz
Keyword(s):  
Numerical Analysis ◽  
Flow Velocity ◽  
Flow Through Channel ◽  
Flow Through

Numerical analysis of parts of the installation for transporting the mixture. The mixture consists of sand, stones and water. The analysis concerns the possibility of reducing the flow velocity of the mixture in the installation by means of installing the blades. The article presents an analysis of 10 blades that have been simulated. Speed distributions are presented after passing through the blades and determined which slows the speed of the mixture to the best possible extent.

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