Name: particle image velocimetry investigation of hemodynamics via aortic phantom
Uploaded: 2022-02-25T15:00:00
Description: Watch this Scientific Journal Video about Particle Image Velocimetry Investigation of Hemodynamics via Aortic Phantom at JoVE.com

本研究由韩国国家研究基金会基础科学研究计划支持，该计划由教育部资助（NRF-2021R1I1A3040346和NRF-2020R1A4A1019475）。这项研究还得到了江原国立大学2018年研究资助（PoINT）的支持。

1. 体外 设置
<ol><li>在光学工作台上准备实验装置，包括柱塞泵，数据采集装置（DAQ）以及具有所需系统工程软件和电机控制软件的计算机（见 材料表）（图1）。 注：柱塞泵先前已经过测试和校准，由电机、电机驱动器和线性执行器9组成。</li>
	<li>将包含流速信息的电子表格文件导入系统工程软件。 注意：例如，心?...

<ol>
	<li>Carabello, B. A., Paulus, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aortic+stenosis.">Aortic stenosis.</a> The Lancet. 373 (9667), 956-966 (2009).</li><li>Jakobsen, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Short-and+long-term+mortality+and+stroke+risk+after+transcatheter+aortic+valve+implantation.">Short-and long-term mortality and stroke risk after transcatheter aortic valve implantation.</a> The American Journal of Cardiology. 121 (1), 78-85 (2018).</li><li>Koo, H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computed+tomography+features+of+cuspal+thrombosis+and+subvalvular+tissue+ingrowth+after+transcatheter+aortic+valve+implantation.">Computed tomography features of cuspal thrombosis and subvalvular tissue ingrowth after transcatheter aortic valve implantation.</a> The American Journal of Cardiology. 125 (4), 597-606 (2020).</li><li>Midha, P. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+fluid+mechanics+of+transcatheter+heart+valve+leaflet+thrombosis+in+the+neosinus.">The fluid mechanics of transcatheter heart valve leaflet thrombosis in the neosinus.</a> Circulation. 136 (17), 1598-1609 (2017).</li><li>Abubakar, H., Ahmed, A. S., Subahi, A., Yassin, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thrombus+in+the+Right+Coronary+Sinus+of+Valsalva+Originating+From+the+Left+Atrial+Appendage+Causing+Embolic+Inferior+Wall+Myocardial+Infarction.">Thrombus in the Right Coronary Sinus of Valsalva Originating From the Left Atrial Appendage Causing Embolic Inferior Wall Myocardial Infarction.</a> Journal of Investigative Medicine High Impact Case Reports. 6, 2324709618792023 (2018).</li><li>Charonko, J., Karri, S., Schmieg, J., Prabhu, S., Vlachos, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro,+time-resolved+PIV+comparison+of+the+effect+of+stent+design+on+wall+shear+stress.">In vitro, time-resolved PIV comparison of the effect of stent design on wall shear stress.</a> Annals of Biomedical Engineering. 37 (7), 1310-1321 (2009).</li><li>Hariharan, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inter-laboratory+characterization+of+the+velocity+field+in+the+FDA+blood+pump+model+using+particle+image+velocimetry+(PIV).">Inter-laboratory characterization of the velocity field in the FDA blood pump model using particle image velocimetry (PIV).</a> Cardiovascular Engineering and Technology. 9 (4), 623-640 (2018).</li><li>Lim, W., Chew, Y., Chew, T., Low, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulsatile+flow+studies+of+a+porcine+bioprosthetic+aortic+valve+in+vitro:+PIV+measurements+and+shear-induced+blood+damage.">Pulsatile flow studies of a porcine bioprosthetic aortic valve in vitro: PIV measurements and shear-induced blood damage.</a> Journal of Biomechanics. 34 (11), 1417-1427 (2001).</li><li>Kim, J., Lee, Y., Choi, S., Ha, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulsatile+flow+pump+based+on+an+iterative+controlled+piston+pump+actuator+as+an+in-vitro+cardiovascular+flow+model.">Pulsatile flow pump based on an iterative controlled piston pump actuator as an in-vitro cardiovascular flow model.</a> Medical Engineering &amp; Physics. 77, 118-124 (2020).</li><li>Moore, B. L., Dasi, L. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+flow+impacts+aortic+leaflet+mechanics+and+aortic+sinus+hemodynamics.">Coronary flow impacts aortic leaflet mechanics and aortic sinus hemodynamics.</a> Annals of Biomedical Engineering. 43 (9), 2231-2241 (2015).</li><li>Evans, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Practical 3D printers: The science and art of 3D printing. , (2012).</li><li>Yudi, M. B., Sharma, S. K., Tang, G. H., Kini, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+angiography+and+percutaneous+coronary+intervention+after+transcatheter+aortic+valve+replacement.">Coronary angiography and percutaneous coronary intervention after transcatheter aortic valve replacement.</a> Journal of the American College of Cardiology. 71 (12), 1360-1378 (2018).</li><li>Adrian, R. J., Westerweel, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Particle Image Velocimetry. , (2011).</li><li>Deen, N. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+image+pre-processing+for+PIV+of+single-and+two-phase+flows+over+reflecting+objects.">On image pre-processing for PIV of single-and two-phase flows over reflecting objects.</a> Experiments in Fluids. 49 (2), 525-530 (2010).</li><li>Thielicke, W., Stamhuis, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PIVlab-towards+user-friendly,+affordable+and+accurate+digital+particle+image+velocimetry+in+MATLAB.">PIVlab-towards user-friendly, affordable and accurate digital particle image velocimetry in MATLAB.</a> Journal of Open Research Software. 2 (1), (2014).</li><li>Pizer, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adaptive+histogram+equalization+and+its+variations.">Adaptive histogram equalization and its variations.</a> Computer Vision, Graphics, and Image Processing. 39 (3), 355-368 (1987).</li><li>Garcia, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robust+smoothing+of+gridded+data+in+one+and+higher+dimensions+with+missing+values.">Robust smoothing of gridded data in one and higher dimensions with missing values.</a> Computational Statistics &amp; Data Analysis. 54 (4), 1167-1178 (2010).</li><li>Elger, D. F., LeBret, B. A., Crowe, C. T., Roberson, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Engineering Fluid Mechanics. , (2020).</li><li>Raghav, V., Sastry, S., Saikrishnan, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+assessment+of+flow+fields+associated+with+heart+valve+prostheses+using+particle+image+velocimetry+(PIV):+recommendations+for+best+practices.">Experimental assessment of flow fields associated with heart valve prostheses using particle image velocimetry (PIV): recommendations for best practices.</a> Cardiovascular Engineering and Technology. 9 (3), 273-287 (2018).</li><li>Ncho, B., Sadri, V., Ortner, J., Kollapaneni, S., Yoganathan, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In-Vitro+Assessment+of+the+Effects+of+Transcatheter+Aortic+Valve+Leaflet+Design+on+Neo-Sinus+Geometry+and+Flow.">In-Vitro Assessment of the Effects of Transcatheter Aortic Valve Leaflet Design on Neo-Sinus Geometry and Flow.</a> Annals of Biomedical Engineering. 49 (3), 1046-1057 (2021).</li><li>Graftieaux, L., Michard, M., Grosjean, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combining+PIV,+POD+and+vortex+identification+algorithms+for+the+study+of+unsteady+turbulent+swirling+flows.">Combining PIV, POD and vortex identification algorithms for the study of unsteady turbulent swirling flows.</a> Measurement Science and Technology. 12 (9), 1422 (2001).</li><li>Yap, C. H., Saikrishnan, N., Tamilselvan, G., Yoganathan, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+measurement+of+dynamic+fluid+shear+stress+on+the+aortic+surface+of+the+aortic+valve+leaflet.">Experimental measurement of dynamic fluid shear stress on the aortic surface of the aortic valve leaflet.</a> Biomechanics and Modeling in Mechanobiology. 11 (1), 171-182 (2012).</li><li>Toninato, R., Salmon, J., Susin, F. M., Ducci, A., Burriesci, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physiological+vortices+in+the+sinuses+of+Valsalva:+an+in+vitro+approach+for+bio-prosthetic+valves.">Physiological vortices in the sinuses of Valsalva: an in vitro approach for bio-prosthetic valves.</a> Journal of Biomechanics. 49 (13), 2635-2643 (2016).</li><li>Raghav, V., Midha, P., Sharma, R., Babaliaros, V., Yoganathan, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcatheter+aortic+valve+thrombosis:+a+review+of+potential+mechanisms.">Transcatheter aortic valve thrombosis: a review of potential mechanisms.</a> Journal of the Royal Society Interface. 18 (184), 20210599 (2021).</li><li>Ramanathan, T., Skinner, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+blood+flow.">Coronary blood flow.</a> Continuing Education in Anaesthesia, Critical Care &amp; Pain. 5 (2), 61-64 (2005).</li><li>Nobach, H., Bodenschatz, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limitations+of+accuracy+in+PIV+due+to+individual+variations+of+particle+image+intensities.">Limitations of accuracy in PIV due to individual variations of particle image intensities.</a> Experiments in Fluids. 47 (1), 27-38 (2009).</li><li>G&#252;lan, U., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Performance+analysis+of+the+transcatheter+aortic+valve+implantation+on+blood+flow+hemodynamics:+An+optical+imaging-based+in+vitro+study.">Performance analysis of the transcatheter aortic valve implantation on blood flow hemodynamics: An optical imaging-based in vitro study.</a> Artificial Organs. 43 (10), 282-293 (2019).</li></ol>

由于TAVI后窦的几何形状不同，窦流发生了变化。漩涡是由主动脉瓣打开和与收缩素22的前射流的相互作用形成的。在没有天然小叶的人工手术瓣膜的研究中，在收缩期在窦区观察到的涡旋正常23。该研究通过减少前射流并进入鼻窦来形成舒张时呈现的涡旋。窦流遇到本地小叶;结果，它在本地小叶下方顺时针拆分，在上方逆时针拆分。这表明TAVI后的患者与没有血...

主动脉瓣狭窄是老年人的常见疾病，当主动脉瓣不打开时，会减少血流量。该问题是由主动脉瓣1的增厚或钙化引起的。因此，这是一种必要的治疗方法，可以增强血液流动并减少心脏的负荷。它通过重塑主动脉瓣或用人工瓣膜代替它来治疗。本研究的重点是经导管主动脉瓣植入术（TAVI），使用导管用人工主动脉瓣取代功能异常的主动脉瓣。
TAVI已被推荐用于手术中受到挑战的患者，死亡率也很低2。近日，已有报道，TAVI患者血栓引起瓣膜功能障碍和中风3，4。怀疑主动脉窦和新窦中的血栓，其原因可能是TAVI引起的血流动力学变化。它是在不删除本地传单的情况下执行的;这些小叶会扰乱鼻窦流动并增加血栓形成的风险5。
很难确定TAVI如何影响血流以及如何在患者中诱导血栓形成。希望阐明血流与 体内血栓形成之间的关系。然而，缺乏测量血流的实用技术使这成为问题。另一方面， 体外 技术具有通过限制必须研究的参数来监测血流变化的优点。 体外 设置和颗粒图像测速（PIV）已被用于识别医疗领域的速度6，7，8。因此， 体外 和PIV足以通过模仿患者的病情来确定要报告的参数：心率和压力，粘度和鼻窦几何形状，并允许人们控制这些参数。
在这项研究中， 体外 设置和PIV用于研究TAVI后主动脉窦的血流。该方案描述了PIV的主动脉幻像和TAVI以及数据采集过程和后处理流量分析。推导了各种血流动力学参数，包括速度，静止，涡旋，涡度和颗粒驻留。结果表明， 体外 设置和PIV有助于研究主动脉窦的血流动力学特征。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>3D Printer</td>
			<td>Prusa Research</td>
			<td></td>
			<td>Original Prusa i3 MK2; FDM printer</td>
		</tr>
		<tr>
			<td>Aluminum bar (square)</td>
			<td>APSPRO</td>
			<td>KHP-3030, KHP-6060</td>
			<td>Dimension: 30 mm x 30 mm, 60 mm x 60 mm</td>
		</tr>
		<tr>
			<td>Bulb pump</td>
			<td>Skyhope</td>
			<td></td>
			<td>MHL-1</td>
		</tr>
		<tr>
			<td>Camera controlling software</td>
			<td>Phantom</td>
			<td>PCC 3.4 software</td>
			<td>The software controll the high speed camera</td>
		</tr>
		<tr>
			<td>Check valve</td>
			<td>HANJU STEEL PIPE</td>
			<td></td>
			<td>Check valve; 1/2 inch (15A)</td>
		</tr>
		<tr>
			<td>Digital Aqusition device</td>
			<td>National Instruments</td>
			<td></td>
			<td>USB-6001</td>
		</tr>
		<tr>
			<td>Glycerin</td>
			<td>ANU Korea</td>
			<td></td>
			<td>It used for making a working fluid</td>
		</tr>
		<tr>
			<td>High-speed camera</td>
			<td>Phantom</td>
			<td></td>
			<td>Phantom VEO 710E-L</td>
		</tr>
		<tr>
			<td>Laser</td>
			<td>Changchun New Industries Optoelectronics Technology</td>
			<td></td>
			<td>MGL-W-532; CW Nd:YAG Laser</td>
		</tr>
		<tr>
			<td>Linear actuator</td>
			<td>THOMSON</td>
			<td></td>
			<td>PC-40; it converts the rotational motion to lenear motion</td>
		</tr>
		<tr>
			<td>Macro lens</td>
			<td>Nikon</td>
			<td></td>
			<td>VR Micro-NIKKOR 105mm, f/1.4</td>
		</tr>
		<tr>
			<td>Motor</td>
			<td>KOLLMORGEN</td>
			<td></td>
			<td>AKM33H-ANCNR-00; DC servo motor</td>
		</tr>
		<tr>
			<td>Motor controlling software</td>
			<td>KOLLMORGEN</td>
			<td></td>
			<td>Kollmorgen software; the software controll the motor driver</td>
		</tr>
		<tr>
			<td>Motor driver</td>
			<td>KOLLMORGEN</td>
			<td></td>
			<td>AKD-B00606-NBAN-0000</td>
		</tr>
		<tr>
			<td>Open-source electronic prototypic platform</td>
			<td>Arduino</td>
			<td>A000066</td>
			<td>Arduino Uno R3. It used for making a external trigger</td>
		</tr>
		<tr>
			<td>Optic table</td>
			<td>SMTECH</td>
			<td></td>
			<td>1800 (W) x 900 (B) x 800 (H)</td>
		</tr>
		<tr>
			<td>Particle</td>
			<td>Dantec Dynamics</td>
			<td>80A6011</td>
			<td>Hollow Glass Sphere. Mean diameter:10 &#181;m, Density: 1090 kg/m3</td>
		</tr>
		<tr>
			<td>PIVlab</td>
			<td>PIVlab</td>
			<td></td>
			<td>Open source algorithm based on MATLAB 
			https://kr.mathworks.com/matlabcentral/fileexchange/27659-pivlab-particle-image-velocimetry-piv-tool-with-gui</td>
		</tr>
		<tr>
			<td>Pressure gauge</td>
			<td>OMEGA</td>
			<td></td>
			<td>PX309-015A5V. Measurement range: 0~15psi</td>
		</tr>
		<tr>
			<td>Refractometer</td>
			<td>ATAGO</td>
			<td>2350</td>
			<td>R-5000. Hand held refractometer; measurement range: 1.333-1.520</td>
		</tr>
		<tr>
			<td>Resistance valve</td>
			<td>HANJU STEEL PIPE</td>
			<td></td>
			<td>Ball valve; 1/2 inch (15A)</td>
		</tr>
		<tr>
			<td>Saline</td>
			<td>DAI HAN PHARM</td>
			<td></td>
			<td>It is used for making a working fluid and for preserving the TAV</td>
		</tr>
		<tr>
			<td>Silicone hose</td>
			<td>HSW</td>
			<td></td>
			<td>Inner diameter 26mm, Outter diameter 30mm; Inlet length 5m, Outlet length 1.5m</td>
		</tr>
		<tr>
			<td>System enginnering software</td>
			<td>National Instruments</td>
			<td></td>
			<td>LabVIEW software. The software controlls the DAQ.</td>
		</tr>
		<tr>
			<td>Transcatheter Aortic Valve, TAV (23 mm) and TAV (26 mm)</td>
			<td>Edwards Lifesciences</td>
			<td></td>
			<td>SAPIEN3 23mm, SAPIEN3 26mm. It is supported by Seoul Asan Medical</td>
		</tr>
		<tr>
			<td>Viscosmeter</td>
			<td>Brookfiled</td>
			<td></td>
			<td>DVELV; Measurement range: 1-2x109 cp</td>
		</tr>
	</tbody>
</table>

particle image velocimetry investigation of hemodynamics via aortic phantom

最近有经导管主动脉瓣植入术 （TAVI） 患者主动脉瓣功能障碍和卒中的报道。已怀疑主动脉窦和新窦中由于血流动力学改变而出现血栓。 体外 实验有助于研究 体内 评估证明有限的情况下的血流动力学特征。 体外 实验也更加稳健，可变参数易于控制。粒子图像测速（PIV）是一种用于 体外 研究的流行测速方法。它提供了高分辨率的速度场，因此甚至可以观察到小尺度的流动特征。本研究的目的是展示如何使用PIV来研究TAVI后主动脉窦的流场。描述了主动脉幻象的 体外 设置，用于PIV的TAVI以及数据采集过程和后处理流程分析。推导血流动力学参数，包括速度、流动停滞、涡旋、涡度和颗粒驻留。结果证实， 体外 实验和PIV有助于研究主动脉窦的血流动力学特征。

速度场根据 图4中的阀门直径显示出不同的正弦流结构。对于TAV（23 mm），TAV和STJ之间的速度高于0.05 m / s，从早期收缩到使用转发射流打开的TAV峰值收缩。然后将高速分布在收缩期晚期支架附近的狭窄范围内。舒张期速度低于0.025 m/s，出现2个低速涡流。对于TAV（26毫米），当阀门打开时，在STJ处测量高速。除早期收缩外，鼻窦速度分布均低于0.05 m/s。具体而言，收缩晚期的速...

Watch this Scientific Journal Video about Particle Image Velocimetry Investigation of Hemodynamics via Aortic Phantom at JoVE.com

Particle Image Velocimetry Investigation of Hemodynamics via Aortic Phantom

本方案描述了为研究通过经导管主动脉瓣（TAV）的 体外 设置的窦流而进行的颗粒图像测速（PIV）测量。还确定了基于速度的血流动力学参数。

通过主动脉幻影进行血液动力学的粒子图像测速

Aortic valve dysfunction and stroke have recently been reported in transcatheter aortic valve implantation (TAVI) patients. Thrombus in the aortic sinus ...

速度信息对于评估瓣膜血流至关重要。我们的协议获取实例速度场，从而对血液动力学进行详细分析。该协议的主要优点是，它可以通过假体心脏瓣膜植入术获得主动脉窦中的实例速度场，这很难从体内实验中获得。目前的方案将有助于表征经导管主动脉瓣植入后的异常血流动力学。基于获得的血液动力学，研究人员将能够开发出更好的心脏瓣膜。获得良好的粒子图像用于粒子图像测速的过程很复杂。对于初学者，建议获取具有不同帧速率的粒子图像并比较每个结果。首先，在光学工作台上准备实验装置，包括柱塞泵，数据采集装置以及具有所需系统工程软件和电机控制软件的计算机。将电子表格文件导入到具有流速信息的系统工程软件中。用方形铝条将丙烯酸窦模型固定在光学台上。用硅胶软管连接油箱、柱塞泵和亚克力鼻窦模型。将原生小叶上的固定TAV与丙烯酸鼻窦模型相结合。将高速相机放在两轴横移上并移动横移。打开激光器，将其设置为七瓦，然后将激光片放置在TAV的中心。拍摄照片并检查最大粒子距离是否小于四到六个像素。设置相机控制软件参数，分辨率为 1， 280 x 720，帧速率为 300 帧/秒，曝光由突发周期强制，连拍计数为 3，连拍周期为 200 微秒和 150 微秒。捕获14个连续循环的粒子图像，并总共重复7次。通过将要分析的区域与要丢弃的区域分开来制作面罩。使用开源工具，基于MATLAB的PIVlab通过导入由时间分辨方法或成对方法保存的粒子图像来执行PIV。导入蒙版并将其应用于所有粒子图像。执行对比度限制自适应直方图均衡，使用快速傅里叶变换执行关于转换为频域的粒子图像对的互相关。设置多通询问窗口，使用相关性结果中的二乘三高斯拟合找到峰值。计算速度场，使用内部代码和内置函数推导出血流动力学参数。对于23毫米TAV，从早期收缩到收缩高峰，TAV和窦管交界处之间的速度高于每秒0.05米。舒张期的速度低于每秒0.025米，出现了两个低速涡流。对于除收缩早期外的26毫米TAV，窦内的速度分布低于每秒0.05米。具体而言，在收缩后期，速度低于其他时间。23毫米TAV的峰值速度高于26毫米TAV。23毫米TAV形成的淤滞区域较宽，但淤滞率较低。在23毫米TAV的原生小叶上方和下方注意到两个类似的漩涡。然而，对于26毫米TAV，顺时针涡旋不清楚，逆时针涡旋具有椭圆形。涡度显示出与涡旋相似的结果。粒子驻留快照显示粒子在窦区分布2秒，粒子停留百分比显示剩余粒子在窦区14秒内的比例。26毫米TAV比23毫米TAV下降得更快，然而，在这两种情况下，颗粒的释放并不相同。速度场的推导是最关键的一步。上述步骤是用于推导速度场的过程，适用于 PIV。该协议可用于研究各种心血管系统中的血流动力学，例如狭窄动脉和心脏瓣膜。

Research

JoVE Journal

Engineering

Particle Image Velocimetry Investigation of Hemodynamics via Aortic Phantom

Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses

超短激光脉冲诱导的等离子体演化早期的调查

Early plasma is generated owing to high intensity laser irradiation of target and the subsequent target material ionization. Its dynamics plays a ...

科研

工程学

Echo Particle Image Velocimetry

回声粒子图像测速技术

The transport of mass, momentum, and energy in fluid flows is ultimately determined by spatiotemporal distributions of the fluid velocity field.1 ...

High-speed Particle Image Velocimetry Near Surfaces

表面附近的高速粒子图像测速

Multi-dimensional and transient flows play a key role in many areas of science, engineering, and health sciences but are often not well understood. The ...

Development of an Experimental Setup for the Measurement of the Coefficient of Restitution under Vacuum Conditions

实验装置的研制归还系数在真空条件下测量

The Discrete Element Method is used for the simulation of particulate systems to describe and analyze them, to predict and afterwards optimize their ...

Use of a Multi-compartment Dynamic Single Enzyme Phantom for Studies of Hyperpolarized Magnetic Resonance Agents

一个多腔动态单一酶幻影超极化磁共振剂研究的用途

Imaging of hyperpolarized substrates by magnetic resonance shows great clinical promise for assessment of critical biochemical processes in real time. Due ...

Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow

湍流应用三维粒子跟踪测速：一喷流病例

3D-PTV is a quantitative flow measurement technique that aims to track the Lagrangian paths of a set of particles in three dimensions using stereoscopic ...

Experimental Investigation of the Flow Structure over a Delta Wing Via Flow Visualization Methods

基于流动可视化方法的三角洲机翼流动结构实验研究

It is well known that the flow field over a delta wing is dominated by a pair of counter rotating leading edge vortices (LEV). However, their mechanism is ...

Simultaneous Measurement of Turbulence and Particle Kinematics Using Flow Imaging Techniques

流成像技术同时测量湍流和粒子运动学

Numerous problems in scientific and engineering fields involve understanding the kinematics of particles in turbulent flows, such as contaminants, marine ...

3D Printing - Evaluating Particle Emissions of a 3D Printing Pen

3D 打印 - 评估 3D 打印笔的粒子排放

Three-dimensional (3D) printing as a type of additive manufacturing shows continuing increase in application and consumer popularity. The fused filament ...

Pneumatically Driven Microfluidic Platform for Micro-Particle Concentration

气动驱动的微流体平台，用于微颗粒浓缩

The present article introduces a method for fabricating and operating a pneumatic valve to control particle concentration using a microfluidic platform. ...