scholarly journals Numerical simulation and in vitro examination of the flow behaviour within coronary stents

2019 ◽  
Vol 5 (1) ◽  
pp. 541-544
Author(s):  
Helena-Sophie Melzer ◽  
Ralf Ahrens ◽  
Andreas E. Guber ◽  
Jakob Dohse
Keyword(s):  
Design Parameters ◽  
Experimental Investigations ◽  
Metallic Stent ◽  
Flow Measurements ◽  
Micro Particle Image Velocimetry ◽  
Micro Piv ◽  
Stent Restenosis ◽  
Image Velocimetry ◽  
Stent Strut

AbstractThis paper discusses the influence of different design parameters of stents by mathematical flow simulations and flow measurements using micro-particle image velocimetry (micro-PIV). A stent strut may cause recirculation areas, which are considered to be the source of thrombosis and the process of in-stent restenosis. The simulations showed that a reduced strut height and a chamfering of the struts reduce these recirculation zones. The numerically determined results were compared with experimental investigations. For this purpose metallic stent structures were transferred into transparent channel systems made of PDMS. The experimental investigations confirm the results of numerical simulations.

Infrared Micro-Particle Image Velocimetry of Fluid Flow in Silicon-Based Microdevices

Volume 4 ◽  
2004 ◽  
Author(s):  
Dong Liu ◽  
Suresh V. Garimella ◽  
Steve T. Wereley
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Capillary Tube ◽  
Surface Flow ◽  
Mems Devices ◽  
Flow Measurements ◽  
Micro Particle Image Velocimetry ◽  
Micro Piv ◽  
Image Velocimetry ◽  
Silicon Based

A non-intrusive diagnostic technique, infrared micro-particle image velocimetry (IR-PIV), is developed for measuring flow fields within MEMS devices with micron-scale resolution. This technique capitalizes on the transparency of silicon in the infrared region, and overcomes the limitation posed by the lack of optical access with visible light to sub-surface flow in silicon-based micro-structures. Experiments with laminar flow of water in a circular micro-capillary tube of hydraulic diameter 255 μm demonstrate the efficacy of this technique. The experimental measurements agree very well with velocity profiles predicted from laminar theory. Cross-correlation and auto-correlation algorithms are employed to measure very-low and moderate-to-high velocities, respectively; the former approach is suitable for biomedical applications while the latter would be needed for measurements in electronics cooling. The results indicate that the IR-PIV technique effectively extends the application of regular micro-PIV techniques, and has great potential for flow measurements in silicon-based microdevices.

Three-Dimensional Micro-Flow Measurement in a Capillary with a Diode Laser Micro-Particle Image Velocitometry

2006 ◽  
Vol 505-507 ◽  
pp. 343-348
Author(s):  
C.T. Pan ◽  
P.J. Cheng ◽  
Yeong-Maw Hwang ◽  
M.F. Chen ◽  
H.S. Chuang ◽  
...  
Keyword(s):  
Diode Laser ◽  
Particle Image ◽  
Three Dimensional ◽  
Calibration Method ◽  
Measurement Range ◽  
Scanning Method ◽  
Micro Particle Image Velocimetry ◽  
Micro Piv ◽  
Image Velocimetry ◽  
Micro Flow

A self-built micro-particle image velocimetry (micro-PIV) with a diode laser is established to measure the micro-fluidic phenomenon in a 100 μm rectangular capillary. By scanning method, a 3-D flow image with a flowrate of 0.3 μL/min is presented. With this calibration method, the measurement ability for 3-D micro-fluidic dynamics could be achieved. This technique also reveals its benefit and potential in metrology. Hence, it provides a helpful tool for Bio-MEMS research. The experiment is proceeded under laminar flow, Re= 0.011. The measurement range is ranging from 0.05μm/s to 4.3mm/s. The vector grid resolution is optimized to 2.5 μm.

scholarly journals Flow Measurements in a Blood-Perfused Collagen Vessel Using X-Ray Micro-Particle Image Velocimetry

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
pp. e81198 ◽  
Author(s):  
Elizabeth Antoine ◽  
Cara Buchanan ◽  
Kamel Fezzaa ◽  
Wah-Keat Lee ◽  
M. Nichole Rylander ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Flow Measurements ◽  
X Ray ◽  
Micro Particle Image Velocimetry ◽  
Image Velocimetry

scholarly journals In Vitro Behavior and Surface Morphology of Modified 316L Stainless Steel Stents

2008 ◽  
Vol 14 (S3) ◽  
pp. 35-36 ◽  
Author(s):  
J. Nunes ◽  
A.P. Piedade ◽  
C.B. Duarte ◽  
M.T. Vieira
Keyword(s):  
Stainless Steel ◽  
316L Stainless Steel ◽  
Cardiovascular Surgery ◽  
Research Work ◽  
Bare Metal Stents ◽  
Metal Stents ◽  
Metallic Stent ◽  
Stent Restenosis ◽  
Drug Eluting

When compared with conventional bare metal stents, such as 316L stainless steel, the introduction of drug-eluting stents can promote reduction in the incidence of in-stent restenosis. However, the chemical discrepancy between the metallic stent and the polymeric material that acts as the reservoir for the drug is responsible for some problems during the cardiovascular surgery. Besides the research work aiming at the development of new bulk alloys for stent production, focus as been also directed to the surface modification of these devices. However, the use of functional graded coatings (FGC), i.e., coatings with a gradient of chemical composition between the substrate and the outmost layer, has never been reported in devices for cardiovascular surgery.

An Evaluation of Auxiliary Part Configuration in the Micro Flow Sensor by Using Micro PIV

2005 ◽  
Author(s):  
Daichi Suzuki ◽  
Takashi Nagumo ◽  
Shinji Honami ◽  
Shoji Kamiunten
Keyword(s):  
Flow Field ◽  
Microfluidic Device ◽  
Flow Behavior ◽  
Flow Sensor ◽  
Sensing Element ◽  
Micro Particle Image Velocimetry ◽  
Micro Piv ◽  
Image Velocimetry ◽  
Bonding Wires ◽  
Micro Flow

The paper describes the configuration effects of the auxiliary parts on the flow behavior around the microfluidic device. Recent development of the devices in MEMS is noticeable. The devices are manufactured in more complicated configuration and arrangement with the auxiliary part for the requirement of higher performance. An evaluation of the flow field around the microfluidic device is strongly required in MEMS design. The aim of the paper is to clarify the effect of the auxiliary part arrangement on the flow field around the micro flow sensor which has both the sensing element and the auxiliary parts such as the pins, pillars and electric bonding wires. The flow around the sensor is measured by using the Micro Particle Image Velocimetry (PIV) system. We investigate four types of the micro flow sensor with different configuration and arrangement of the pin, the bonding wires and the pillars. The result shows that the effect of the supporting pillars is negligible.

Flow and Thermal Investigation of a Groove-Enhanced Minichannel Application

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Stephen A. Solovitz ◽  
Thomas E. Conder
Keyword(s):  
Electronics Cooling ◽  
Leading Edge ◽  
Windward Side ◽  
Leeward Side ◽  
Micro Particle Image Velocimetry ◽  
Micro Piv ◽  
Turbulent Reynolds Number ◽  
Image Velocimetry ◽  
Flow Speeds ◽  
Grooved Surface

A grooved surface feature is considered as a potential thermal enhancement for electronics cooling with single-phase flow in minichannels. A power electronics module was initially designed using applied computational fluid dynamics (CFD) using a minichannel featuring a series of two-dimensional grooves. To validate these simulations, micro–particle image velocimetry (PIV) was used to examine the flow field at a turbulent Reynolds number of 5000. The velocity distribution was compared directly to CFD simulations of the same geometry. The flow structures matched quantitatively near the groove leading edge and on its windward side, but the flow speeds were significantly underpredicted on the leeward side, deviating by as much as 30% of the freestream speed. This discrepancy was attributable to the selection of the turbulence model in the simulations, which was determined using the micro-PIV results. Using a validated CFD model, simulations predict thermal enhancements on the order of 35%.

An Experimental Investigation of the Permeability in Porous Chip Formed by Micropost Arrays Based on Microparticle Image Velocimetry and Micromanometer Measurements

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Haoli Wang ◽  
Pengwei Wang
Keyword(s):  
Cross Section ◽  
Particle Image ◽  
Brinkman Equation ◽  
Two Dimensional ◽  
Micro Particle Image Velocimetry ◽  
Micro Piv ◽  
Image Velocimetry ◽  
Measurement Results ◽  
Microparticle Image Velocimetry ◽  
The Cross

Measurements of velocity and pressure differences for flows in porous chip fabricated with micropost arrays arranged in square pattern were implemented by using micro-particle image velocimetry (micro-PIV) and high precision micromanometer. Based on the measurement results, the permeability was solved by Brinkman equation under the averaged velocities over the cross section, two-dimensional velocities on the center plane of the microchannels, and the averaged velocities on the center plane considering the effect of depth of correlation (DOC), respectively. The experimental results indicate that the nondimensional permeability based on different velocities satisfies the Kozeny–Carman (KC) equation. The Kozeny factor is taken as 40 for the averaged velocity over the cross section and 15 for two kinds of center velocities based on the micropost array of this study, respectively. The permeability calculated by the velocities on the center plane is greater than that by the averaged velocity over the cross section.

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