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Kirsanov RI, Kulikov VP. Helical Blood Flow in Hemodynamically Significant Carotid Stenosis. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2020; 39:543-550. [PMID: 31502308 DOI: 10.1002/jum.15131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 08/14/2019] [Accepted: 08/21/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVES To define helical blood flow (HBF) characteristics in hemodynamically significant atherosclerotic stenosis of the internal carotid artery (ICA) by means of duplex scanning. METHODS Twenty-five hemodynamically significant (65.0% [range, 63.0%-69.0%]) carotid stenoses were examined in 23 patients. The severity of the stenosis was calculated by the European Carotid Surgery Trial grading method by transverse section scanning in the B-mode. Rotational components were estimated in color flow mapping by transverse-section scanning of a vessel at the most narrowed site, as well as in the prestenotic and poststenotic segments. A quantitative evaluation of HBF was performed on the basis of pulsed wave Doppler imaging of longitudinal and transverse sections of the arterial lumen. RESULTS Helical blood flow was most often (68%) registered in the poststenotic segment of the ICA as a single vortex (52%) or double vortices (16%). At the most narrowed site, HBF was registered in 48% of the cases (44% single vortex and 4% double vortices), whereas in the prestenotic segment of the blood vessel, it was registered in only 16% of the cases (8% single vortex and 8% double vortices). The time-averaged maximum blood flow velocities at the most narrowed site were 88.5 cm/s (25th-75th percentiles, 73.8-127.8 cm/s) for the axial component and 33.1 cm/s (22.7-40.9 cm/s) for the rotational component. The calculated summary velocity of motion of the blood particles in helical paths was 92.2 cm/s (75.7-144.2 cm/s). CONCLUSIONS It has been shown that HBF can be registered by Doppler ultrasound in atherosclerotic stenosis, and its registration rate increases while passing through the narrowed segment of the ICA.
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Affiliation(s)
- Roman Ivanovich Kirsanov
- Department of Pathological Physiology, Altai State Medical University, Barnaul, Russia
- Department of Functional Diagnostics, Regional Clinical Hospital, Barnaul, Russia
| | - Vladimir Pavlovich Kulikov
- Department of Clinical Pathophysiology and Functional Diagnostics, Altai Medical Institute of Postgraduate Education, Barnaul, Russia
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Doutel E, Viriato N, Carneiro J, Campos JBLM, Miranda JM. Geometrical effects in the hemodynamics of stenotic and non-stenotic left coronary arteries-numerical and in vitro approaches. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3207. [PMID: 30983149 DOI: 10.1002/cnm.3207] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/09/2019] [Accepted: 04/05/2019] [Indexed: 06/09/2023]
Abstract
Atherosclerosis is a common cardiovascular disease found in the left coronary artery (LCA), closely linked to local hemodynamic, which, in turn, is highly influenced by the artery geometry. The hemodynamics in the LCA was studied in a patient-specific geometry without any sign of disease using both numerical and in vitro approaches. The influence of non-planarity was evaluated through two models of the patient-specific LCA that deviate from its original geometry in their planarity. Afterwards, in all models, irregular stenoses were created by a procedure in which the stenosis emerges by diffusion from low wall shear stress (WSS) areas. The WSS distribution and flow patterns were evaluated in all the models. The experimental results validate the numerical code developed to study the blood flow assuming a steady state Newtonian behavior. Comparison between the planar and non-planar idealized LCA revealed no significant differences in low WSS regions forming stenotic regions with identical shape. In the patient-specific LCA, the low WSS regions are not consistent with the idealized models leading to a different stenosis shape. The results revealed that the non-planarity has an unquestionable effect in helicity. It was also demonstrated that eccentricity of the vessels cross section and the position of the apex in relation to the axis of the parent branch contribute to the flow patterns observed. Numerical results of pulsatile blood flow assuming a non-Newtonian behavior, in the patient-specific LCA, reinforce the non-planarity effect in local hemodynamics.
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Affiliation(s)
- Erica Doutel
- Altice Labs, Rua Eng° José Ferreira Pinto Basto, Aveiro, Portugal
| | - Nuno Viriato
- INEGI, Institute of Mechanical Engineering, FEUP, Faculty of Engineering, University of Porto, Porto, Portugal
| | - João Carneiro
- Transport Phenomena Research Center, Chemical Engineering Department, Faculty of Engineering, University of Porto, Porto, Portugal
| | - João B L M Campos
- Transport Phenomena Research Center, Chemical Engineering Department, Faculty of Engineering, University of Porto, Porto, Portugal
| | - João M Miranda
- Transport Phenomena Research Center, Chemical Engineering Department, Faculty of Engineering, University of Porto, Porto, Portugal
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Prashantha B, Anish S. Computational investigations on the hemodynamic performance of a new swirl generator in bifurcated arteries. Comput Methods Biomech Biomed Engin 2019; 22:364-375. [DOI: 10.1080/10255842.2018.1556974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- B. Prashantha
- Department of Mechanical Engineering, M S Ramaiah Institute of Technology, Bengaluru, Karnataka, India
| | - S. Anish
- Advanced Fluid Mechanics Laboratory, Department of Mechanical Engineering, National Institute of Technology, Surathkal, Karnataka, India
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Discrete-Phase Modelling of an Asymmetric Stenosis Artery Under Different Womersley Numbers. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2019. [DOI: 10.1007/s13369-018-3391-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Ha H, Koo HJ, Huh HK, Kim GB, Kweon J, Kim N, Kim YH, Kang JW, Lim TH, Song JK, Lee SJ, Yang DH. Effect of pannus formation on the prosthetic heart valve: In vitro demonstration using particle image velocimetry. PLoS One 2018; 13:e0199792. [PMID: 29953485 PMCID: PMC6023143 DOI: 10.1371/journal.pone.0199792] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 06/13/2018] [Indexed: 02/06/2023] Open
Abstract
Although hemodynamic influence of the subprosthetic tissue, termed as pannus, may contribute to prosthetic aortic valve dysfunction, the relationship between pannus extent and hemodynamics in the prosthetic valve has rarely been reported. We investigated the fluid dynamics of pannus formation using in vitro experiments with particle image velocimetry. Subvalvular pannus formation caused substantial changes in prosthetic valve transvalvular peak velocity, transvalvular pressure gradient (TPG) and opening angle. Maximum flow velocity and corresponding TPG were mostly affected by pannus width. When the pannus width was 25% of the valve diameter, pannus formation elevated TPG to >2.5 times higher than that without pannus formation. Opening dysfunction was observed only for a pannus involvement angle of 360°. Although circumferential pannus with an involvement angle of 360° decreased the opening angle of the valve from approximately 82° to 58°, eccentric pannus with an involvement angle of 180° did not induce valve opening dysfunction. The pannus involvement angle largely influenced the velocity flow field at the aortic sinus and corresponding hemodynamic indices, including wall shear stress, principal shear stress and viscous energy loss distributions. Substantial discrepancy between the velocity-based TPG estimation and direct pressure measurements was observed for prosthetic valve flow with pannus formation.
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Affiliation(s)
- Hojin Ha
- Department of Mechanical and Biomedical Engineering, Kangwon National University, Chuncheon, South Korea
| | - Hyun Jung Koo
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Hyung Kyu Huh
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, South Korea
| | - Guk Bae Kim
- Asan Institute of Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Jihoon Kweon
- Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Namkug Kim
- Department of Convergence Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Young-Hak Kim
- Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Joon-Won Kang
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Tae-Hwan Lim
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Jae-Kwan Song
- Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Sang Joon Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, South Korea
| | - Dong Hyun Yang
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
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Park H, Jung SY, Park JH, Kim JH, Lee SJ. Enhancement of measurement accuracy of X-ray PIV in comparison with the micro-PIV technique. JOURNAL OF SYNCHROTRON RADIATION 2018; 25:552-559. [PMID: 29488936 DOI: 10.1107/s1600577517017398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 12/04/2017] [Indexed: 06/08/2023]
Abstract
The X-ray PIV (particle image velocimetry) technique has been used as a non-invasive measurement modality to investigate the haemodynamic features of blood flow. However, the extraction of two-dimensional velocity field data from the three-dimensional volumetric information contained in X-ray images is technically unclear. In this study, a new two-dimensional velocity field extraction technique is proposed to overcome technological limitations. To resolve the problem of finding a correction coefficient, the velocity field information obtained by X-ray PIV and micro-PIV techniques for disturbed flow in a concentric stenosis with 50% severity was quantitatively compared. Micro-PIV experiments were conducted for single-plane and summation images, which provide similar positional information of particles as X-ray images. The correction coefficient was obtained by establishing the relationship between velocity data obtained from summation images (VS) and centre-plane images (VC). The velocity differences between VS and VC along the vertical and horizontal directions were quantitatively analysed as a function of the geometric angle of the test model for applying the present two-dimensional velocity field extraction technique to a conduit of arbitrary geometry. Finally, the two-dimensional velocity field information at arbitrary positions could be successfully extracted from X-ray images by using the correction coefficient and several velocity parameters derived from VS.
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Affiliation(s)
- Hanwook Park
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Pohang, Gyeongsangbuk-do 790-784, South Korea
| | - Sung Yong Jung
- Department of Mechanical Engineering, Chosun University, 375 Seosuk-dong, Dong-gu, Gwangju 61452, South Korea
| | - Jun Hong Park
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Pohang, Gyeongsangbuk-do 790-784, South Korea
| | - Jun Ho Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Pohang, Gyeongsangbuk-do 790-784, South Korea
| | - Sang Joon Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Pohang, Gyeongsangbuk-do 790-784, South Korea
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Spiral Laminar Flow: a Survey of a Three-Dimensional Arterial Flow Pattern in a Group of Volunteers. Eur J Vasc Endovasc Surg 2016; 52:674-680. [DOI: 10.1016/j.ejvs.2016.07.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 07/16/2016] [Indexed: 11/18/2022]
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Estimation of turbulent kinetic energy using 4D phase-contrast MRI: Effect of scan parameters and target vessel size. Magn Reson Imaging 2016; 34:715-723. [DOI: 10.1016/j.mri.2016.03.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 02/17/2016] [Accepted: 03/03/2016] [Indexed: 11/18/2022]
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Turbulent Kinetic Energy Measurement Using Phase Contrast MRI for Estimating the Post-Stenotic Pressure Drop: In Vitro Validation and Clinical Application. PLoS One 2016; 11:e0151540. [PMID: 26978529 PMCID: PMC4792455 DOI: 10.1371/journal.pone.0151540] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 02/29/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Although the measurement of turbulence kinetic energy (TKE) by using magnetic resonance imaging (MRI) has been introduced as an alternative index for quantifying energy loss through the cardiac valve, experimental verification and clinical application of this parameter are still required. OBJECTIVES The goal of this study is to verify MRI measurements of TKE by using a phantom stenosis with particle image velocimetry (PIV) as the reference standard. In addition, the feasibility of measuring TKE with MRI is explored. METHODS MRI measurements of TKE through a phantom stenosis was performed by using clinical 3T MRI scanner. The MRI measurements were verified experimentally by using PIV as the reference standard. In vivo application of MRI-driven TKE was explored in seven patients with aortic valve disease and one healthy volunteer. Transvalvular gradients measured by MRI and echocardiography were compared. RESULTS MRI and PIV measurements of TKE are consistent for turbulent flow (0.666 < R2 < 0.738) with a mean difference of -11.13 J/m3 (SD = 4.34 J/m3). Results of MRI and PIV measurements differ by 2.76 ± 0.82 cm/s (velocity) and -11.13 ± 4.34 J/m3 (TKE) for turbulent flow (Re > 400). The turbulence pressure drop correlates strongly with total TKE (R2 = 0.986). However, in vivo measurements of TKE are not consistent with the transvalvular pressure gradient estimated by echocardiography. CONCLUSIONS These results suggest that TKE measurement via MRI may provide a potential benefit as an energy-loss index to characterize blood flow through the aortic valve. However, further clinical studies are necessary to reach definitive conclusions regarding this technique.
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Kandail H, Hamady M, Xu XY. Comparison of Blood Flow in Branched and Fenestrated Stent-Grafts for Endovascular Repair of Abdominal Aortic Aneurysms. J Endovasc Ther 2015; 22:578-90. [DOI: 10.1177/1526602815587261] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Purpose: To report a computational study assessing the hemodynamic outcomes of branched stent-grafts (BSGs) for different anatomic variations. Methods: Idealized models of BSGs and fenestrated stent-grafts (FSGs) were constructed with different visceral takeoff angles (ToA) and lateral aortic neck angles. ToA was defined as the angle between the centerlines of the main stent-graft and side branch, with 90° representing normal alignment, and 30° and 120° representing angulated side branches. Computational simulations were performed by solving the conservation equations governing the blood flow under physiologically realistic conditions. Results: The largest renal flow recirculation zones (FRZs) were observed in FSGs at a ToA of 30°, and the smallest FRZ was also found in FSGs (at a ToA of 120°). For straight-neck stent-grafts with a ToA of 90°, mean flow in each renal artery was 0.54, 0.46, and 0.62 L/min in antegrade BSGs, retrograde BSGs, and FSGs, respectively. For angulated stent-grafts, the corresponding values were 0.53, 0.48, and 0.63 L/min. All straight-neck stent-grafts experienced equal cycle-averaged displacement forces of 1.25, 1.69, and 1.95 N at ToAs of 30°, 90°, and 120°, respectively. Angulated main stent-grafts experienced an equal cycle-averaged displacement force of 3.6 N. Conclusion: The blood flow rate in renal arteries depends on the configuration of the stent-graft, with an FSG giving maximum renal flow and a retrograde BSG resulting in minimum renal flow. Nevertheless, the difference was small, up to 0.09 L/min. Displacement forces exerted on stent-grafts are very sensitive to lateral neck angle but not on the configuration of the stent-graft.
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Affiliation(s)
| | - Mohamad Hamady
- Department of Interventional Radiology, St Mary’s Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Xiao Yun Xu
- Department of Chemical Engineering, Imperial College London, UK
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Ha H, Choi W, Park H, Lee SJ. Effect of swirling blood flow on vortex formation at post-stenosis. Proc Inst Mech Eng H 2015; 229:175-83. [PMID: 25767153 DOI: 10.1177/0954411915573065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Various clinical observations reported that swirling blood flow is a normal physiological flow pattern in various vasculatures. The swirling flow has beneficial effects on blood circulation through the blood vessels. It enhances oxygen transfer and reduces low-density lipoprotein concentration in the blood vessel by enhancing cross-plane mixing of the blood. However, the fluid-dynamic roles of the swirling flow are not yet fully understood. In this study, inhibition of material deposition at the post-stenosis region by the swirling flow was observed. To reveal the underlying fluid-dynamic characteristics, pathline flow visualization and time-resolved particle image velocimetry measurements were conducted. Results showed that the swirling inlet flow increased the development of vortices at near wall region of the post-stenosis, which can suppress further development of stenosis by enhancing transport and mixing of the blood flow. The fluid-dynamic characteristics obtained in this study would be useful for improving hemodynamic characteristics of vascular grafts and stents in which the stenosis frequently occurred. Moreover, the time-resolved particle image velocimetry measurement technique and vortex identification method employed in this study would be useful for investigating the fluid-dynamic effects of the swirling flow on various vascular environments.
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Affiliation(s)
- Hojin Ha
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Woorak Choi
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Hanwook Park
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Sang Joon Lee
- Center for Biofluid and Biomimic Research, Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
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Ha H, Choi W, Lee SJ. Beneficial fluid-dynamic features of pulsatile swirling flow in 45° end-to-side anastomosis. Med Eng Phys 2015; 37:272-9. [DOI: 10.1016/j.medengphy.2015.01.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 11/29/2014] [Accepted: 01/11/2015] [Indexed: 11/17/2022]
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Ha H, Hwang D, Choi WR, Baek J, Lee SJ. Fluid-dynamic optimal design of helical vascular graft for stenotic disturbed flow. PLoS One 2014; 9:e111047. [PMID: 25360705 PMCID: PMC4215892 DOI: 10.1371/journal.pone.0111047] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Accepted: 09/22/2014] [Indexed: 11/18/2022] Open
Abstract
Although a helical configuration of a prosthetic vascular graft appears to be clinically beneficial in suppressing thrombosis and intimal hyperplasia, an optimization of a helical design has yet to be achieved because of the lack of a detailed understanding on hemodynamic features in helical grafts and their fluid dynamic influences. In the present study, the swirling flow in a helical graft was hypothesized to have beneficial influences on a disturbed flow structure such as stenotic flow. The characteristics of swirling flows generated by helical tubes with various helical pitches and curvatures were investigated to prove the hypothesis. The fluid dynamic influences of these helical tubes on stenotic flow were quantitatively analysed by using a particle image velocimetry technique. Results showed that the swirling intensity and helicity of the swirling flow have a linear relation with a modified Germano number (Gn*) of the helical pipe. In addition, the swirling flow generated a beneficial flow structure at the stenosis by reducing the size of the recirculation flow under steady and pulsatile flow conditions. Therefore, the beneficial effects of a helical graft on the flow field can be estimated by using the magnitude of Gn*. Finally, an optimized helical design with a maximum Gn* was suggested for the future design of a vascular graft.
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Affiliation(s)
- Hojin Ha
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea
| | - Dongha Hwang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea
| | - Woo-Rak Choi
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea
| | - Jehyun Baek
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea
| | - Sang Joon Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea
- Center for Biofluid and Biomimic Research, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Republic of Korea
- * E-mail:
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