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Ahirwar D, Khurana D, Chowdhury SR. Modeling, Simulation and Validation of Alteration in Blood Flow and Regional Oxygenation Under Arterial Occlusion. J Med Syst 2022; 46:74. [PMID: 36195803 DOI: 10.1007/s10916-022-01861-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/30/2022] [Indexed: 11/28/2022]
Abstract
The paper presents the mathematical modeling along with an experimental approach for the identification of arterial occlusion condition. Arterial occlusion occurs due to development of constriction and/or thrombus in the lumen of the artery. A geometry of the thrombus has been modeled for the analysis of the arterial occlusion condition in modeling part. The proposed model of the thrombus has been simulated using Comsol® multiphysics considering different hemodynamic parameters. Variation in regional oxygen saturation (rSO2) of the arterial occlusion condition has been validated with experimental process, where occlusion of the artery has been done by applying external pressure. The experimental study has been conducted to monitor alteration in rSO2 level profile for occlusion using near infrared spectroscopy (NIRS) methodology. NIRS signal data has been collected from twenty-three subjects with no reported musculoskeletal, psychiatric, or any other neurological deficits using Mespere NeurOs® oxymeter. Experimental data reveal that the oxygenation level decreases considerably due to arterial occlusion as compared to the healthy condition at 95% of confidence interval (p < .05). Dynamic time warping algorithm reveals that variation in rSO2 due to proposed thrombus geometry has more similarity with experimental study.
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Affiliation(s)
- Dalchand Ahirwar
- Biomedical Systems Laboratory, School of Computing and Electrical Engineering, Indian Institute of Technology, Mandi, India
| | - Dheeraj Khurana
- Department of Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Shubhajit Roy Chowdhury
- Biomedical Systems Laboratory, School of Computing and Electrical Engineering, Indian Institute of Technology, Mandi, India.
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Kamangar S. Numerical simulation of pulsatile blood flow characteristics in a multi stenosed coronary artery. Biomed Mater Eng 2021; 32:309-321. [PMID: 33998530 DOI: 10.3233/bme-211234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Coronary artery disease is reported as one of the most common sources of death all over the world. The presence of stenosis (plaque) in the coronary arteries results in the restriction of blood supply, which leads to myocardial infarction. OBJECTIVE The aim of this study was to investigate the effect of multi stenosis on hemodynamics parameters in idealized coronary artery models with varying degrees of stenosis and interspace distance between the stenosis. METHODS A finite volume-based software package (Ansys CFX version 17.2) was employed to model the blood flow. The hemodynamic stenosis parameters of blood, such as the pressure, velocity, and wall shear stress were obtained. RESULTS The computed results showed that the pressure drop is maximum across the 90% area stenosis (AS). The pressure drop is increased as the distance between the proximal and distal stenosis is decreased across the proximal stenosis for the model P70_D70 during the systolic period of the cardiac cycle. A recirculation zone is formed behind the stenosis and is restricted by the occurrence of distal stenosis as the interspacing distance decreases, which could lead to further progression of stenosis in the flow-disturbed area. The wall shear stress was found to increase as the distance between the proximal and distal stenosis is increased across the distal stenosis. The maximum wall shear stress was found at 90% AS. CONCLUSIONS In the clinical diagnosis, an overestimation of distal stenosis severity could be possible. Furthermore, the low wall shear stress zone in between the proximal and distal stenosis may help atherosclerotic growth or merge adjacent stenosis.
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Affiliation(s)
- Sarfaraz Kamangar
- Research Centre for Advanced Materials Science (RCAMS), King Khalid University, Abha, Kingdom Saudi Arabia.,Department of Mechanical Engineering, College of Engineering, King Khalid University, Abha, Kingdom Saudi Arabia E-mail:
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Bennati L, Vergara C, Domanin M, Malloggi C, Bissacco D, Trimarchi S, Silani V, Parati G, Casana R. A Computational Fluid-Structure Interaction Study for Carotids With Different Atherosclerotic Plaques. J Biomech Eng 2021; 143:091002. [PMID: 33876184 DOI: 10.1115/1.4050910] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Indexed: 11/08/2022]
Abstract
Atherosclerosis is a systemic disease that leads to accumulation of deposits, known as atherosclerotic plaques, within the walls of the carotids. In particular, three types of plaque can be distinguished: soft, fibrous, and calcific. Most of the computational studies who investigated the interplay between the plaque and the blood flow on patient-specific geometries used nonstandard medical images to directly delineate and segment the plaque and its components. However, these techniques are not so widely available in the clinical practice. In this context, the aim of our work was twofold: (i) to propose a new geometric tool that allowed to reconstruct a plausible plaque in the carotids from standard images and (ii) to perform three-dimensional (3D) fluid-structure interaction (FSI) simulations where we compared some fluid-dynamic and structural quantities among 15 patients characterized by different typologies of plaque. Our results highlighted that both the morphology and the mechanical properties of different plaque components play a crucial role in determining the vulnerability of the plaque.
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Affiliation(s)
- Lorenzo Bennati
- Department of Surgery, Dentistry, Paediatrics and Gynaecology, University of Verona, Verona 37129, Italy
| | - Christian Vergara
- LABS, Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta," Politecnico di Milano, Milan 20133, Italy
| | - Maurizio Domanin
- Vascular Surgery Unit, IRCCS, Ospedale Maggiore Policlinico, Milan 20133, Italy; Department of Clinical Sciences and Community Health, University of Milan, Milan 20133, Italy
| | - Chiara Malloggi
- Laboratory of Research in Vascular Surgery, Istituto Auxologico Italiano, IRCCS, Milan 20133, Italy
| | - Daniele Bissacco
- Vascular Surgery Unit, IRCCS, Ospedale Maggiore Policlinico, Milan 20133, Italy
| | - Santi Trimarchi
- Vascular Surgery Unit, IRCCS, Ospedale Maggiore Policlinico, Milan 20133, Italy; Department of Clinical Sciences and Community Health, University of Milan, Milan 20133, Italy
| | - Vincenzo Silani
- Department of Neurology-Stroke Unit and Laboratory of Neuroscience, Ospedale San Luca, Istituto Auxologico Italiano, IRCCS, Milan 20133, Italy; Department of Pathophysiology and Transplantation, University of Milan, Milan 20133, Italy
| | - Gianfranco Parati
- Department of Cardiovascular, Neural and Metabolic Sciences, Ospedale San Luca, Istituto Auxologico Italiano, IRCCS, Milan 20133, Italy; Department of Medicine and Surgery, Università di Milano-Bicocca, Monza 20900, Italy
| | - Renato Casana
- Laboratory of Research in Vascular Surgery, Istituto Auxologico Italiano, IRCCS, Milan 20133, Italy; Department of Surgery, Istituto Auxologico Italiano, IRCCS, Milan 20133, Italy
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Sandeep S, Shine SR. Effect of stenosis and dilatation on the hemodynamic parameters associated with left coronary artery. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 204:106052. [PMID: 33789214 DOI: 10.1016/j.cmpb.2021.106052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/09/2021] [Indexed: 05/10/2023]
Abstract
BACKGROUND AND OBJECTIVE The main objective of the work is to examine the curvature effects of stenosis/dilatation region pertaining to left coronary artery. The hemodymamic features during the cardiac cycle is thoroughly examined. METHODS A numerical fluid structure interaction model incorporating multi- layered elastic artery wall, non-Newtonian blood viscosity and pulsating boundary conditions is developed. The composite arterial wall consists of a thin layer tunica intima, atheroma and a thick wall. Higher stiffness of atheroma is captured by using higher Young's modulus. The CFD and FSI models are validated with available experimental and analytical data. Computations are done with five different non-Newtonian models and arterial wall with various elasticity levels. The local and time averaged WSS, velocity contours downstream of stenosis, wall pressure and pressure drop during various phases of cardiac cycle are provided in detail. RESULTS The influence of non-Newtonian effects of blood viscosity is found to be significant especially at stenosis regions. The flexible wall caused wall deformation and the associated flow and pressure wave propagation affecting WSS and pressure drop compared to the rigid wall. Flow recirculation is noticed at stenosis downstream locations and its strength increases with increased severity of the stenosis. A stenosis is characterised by a sudden drop in wall pressure and a slower two stage recovery during peak velocity periods of the cardiac cycle. CONCLUSIONS The pressure drop, local WSS at stenosis centre, and radial velocity increase are significantly higher for stenosis cases and the effect is severe during peak diastole. The variation in hemodynamic parameters is found to be less significant for dilatation. Significantly lower WSS is noticed for the recirculation regions downstream of stenosis which can enhance the tendency for monocytes to attach to the endothelium. The radius of curvature of the stenosis is found to be the most sensitive parameter affecting the hemodynamic characteristics rather than the detailed geometry of the stenosis. The main effect of variation of artery wall stiffness is noted at recirculation regions present downstream of stenosis. The results from the study may be useful for predicting wall shear stress signatures associated with stenosis/dilatation changes and the management of specific cases.
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Affiliation(s)
- Sreelakshmi Sandeep
- Department of Aerospace Engineering, Indian Institute of Space Science and Technology, IIST, Thiruvananthapuram, 695547, India
| | - S R Shine
- Department of Aerospace Engineering, Indian Institute of Space Science and Technology, IIST, Thiruvananthapuram, 695547, India.
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Ozden K, Sert C, Yazicioglu Y. Effect of stenosis shape on the sound emitted from a constricted blood vessel. Med Biol Eng Comput 2020; 58:643-658. [PMID: 31939056 DOI: 10.1007/s11517-020-02119-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 01/03/2020] [Indexed: 01/14/2023]
Abstract
Effect of stenosis shape on the post-stenotic pressure fluctuations and the sound emitted from a constricted blood vessel is studied numerically. Large eddy simulations are performed using OpenFOAM under pulsatile flow conditions with a non-Newtonian fluid model. Findings indicate that the high slope at the stenosis entrance and overlap of more than one stenosis shorten the length of the flow jet, trigger turbulence, and increase vortical activity, turbulent kinetic energy, and magnitude of pressure fluctuations at the post-stenotic region. Also, these morphological parameters strengthen the audible signal especially in the systolic phase of the pulsatile flow. On the other hand, asymmetry of the stenosis creates an opposite effect. Based on the wall pressure data, it is shown that the stenosis shape affects the intensity and the pattern of the murmurs generated. Stenosis shape is found to be an essential factor for the acoustic-based non-invasive diagnosis of stenosis. Graphical abstract Wall pressure content of the elliptic stenosis shape.
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Affiliation(s)
- Kamil Ozden
- ROKETSAN Missile Industries Inc, Elmadag, 06780, Ankara, Turkey
| | - Cuneyt Sert
- Department of Mechanical Engineering, Middle East Technical University, 06800, Ankara, Turkey.
| | - Yigit Yazicioglu
- Department of Mechanical Engineering, Middle East Technical University, 06800, Ankara, Turkey
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Alegre-Martínez C, Choi KS, Tammisola O, McNally D. On the axial distribution of plaque stress: Influence of stenosis severity, lipid core stiffness, lipid core length and fibrous cap stiffness. Med Eng Phys 2019; 68:76-84. [DOI: 10.1016/j.medengphy.2019.02.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 02/12/2019] [Accepted: 02/25/2019] [Indexed: 10/27/2022]
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Nejad AA, Talebi Z, Cheraghali D, Shahbani-Zahiri A, Norouzi M. Pulsatile flow of non-Newtonian blood fluid inside stenosed arteries: Investigating the effects of viscoelastic and elastic walls, arteriosclerosis, and polycythemia diseases. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2018; 154:109-122. [PMID: 29249336 DOI: 10.1016/j.cmpb.2017.11.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 10/27/2017] [Accepted: 11/14/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND AND OBJECTIVE In this study, the interaction of pulsatile blood flow with the viscoelastic walls of the axisymmetric artery is numerically investigated for different severities of stenosis. The geometry of artery is modeled by an axisymmetric cylindrical tube with a symmetric stenosis in a two-dimensional case. The effects of stenosis severity on the axial velocity profile, pressure distribution, streamlines, wall shear stress, and wall radial displacement for the viscoelastic artery are also compared to the elastics artery. Furthermore, the effects of atherosclerosis and polycythemia diseases on the hemodynamics and the mechanical behavior of arterial walls are investigated. METHODS The pulsatile flow of non-Newtonian blood is simulated inside the viscoelastic artery using the COMSOL Multiphysics software (version 5) and by employing the fluid-structure interaction (FSI) method and the arbitrary Lagrangian-Eulerian (ALE) method. Moreover, finite element method (FEM) is used to solve the governing equations on the unstructured grids. For modeling the non-Newtonian blood fluid and the viscoelastic arterial wall, the modified Casson model, and generalized Maxwell model are used, respectively. RESULTS According to the results, with stenosis severity increasing from 25% to 75% at the time of maximum volumetric flow rate, the maximum value of axial velocity and its gradient increase 7.9 and 19.6 times, and the maximum wall shear stress of viscoelastic wall increases 24.2 times in the constriction zone. With the progression of the atherosclerosis disease (fivefold growth of arterial elastic modulus), the wall radial displacement of viscoelastic arterial walls decreases nearly 40%. CONCLUSIONS In this study, axial velocity profile, pressure distribution, streamlines, wall radial displacement, and wall shear stress were examined for different percentages of stenosis (25%, 50%, and 75%). The atherosclerosis disease was investigated by the fivefold growth of viscoelastic arterial elastic modulus and polycythemia disease was examined by the 21-fold increase in the yield stress of the blood fluid. Furthermore, the comparison of results between the elastic and viscoelastic arterial walls shows that the wall radial displacement for viscoelastic artery is lower than that for the elastic artery as much as 21.7% for the severe stenosis of 75%.
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Affiliation(s)
- A Abbas Nejad
- Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran
| | - Z Talebi
- Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran
| | - D Cheraghali
- Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran
| | - A Shahbani-Zahiri
- Department of Mechanical Engineering, University of Birjand, Birjand, Iran
| | - M Norouzi
- Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran.
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Mandal AP, Mandal PK. Distribution and retention of drug through an idealised atherosclerotic plaque eluted from a half-embedded stent. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/s40435-017-0372-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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GOVINDARAJU KALIMUTHU, VISWANATHAN GIRISHN, BADRUDDIN IRFANANJUM, WELDEMARIAM SIRAKAREGAWI, GEBREHIWOT WOLDUZINA, KAMANGAR SARFARAZ. THE MECHANICAL FACTORS INFLUENCING THE ASSESSMENT OF INTERMEDIATE STENOSIS SEVERITY EXPLAINED THROUGH FRACTIONAL FLOW RESERVE. J MECH MED BIOL 2017. [DOI: 10.1142/s0219519417300010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Assessment of intermediate coronary lesions with diameter stenosis of 40% to 70% severity is being a challenge for cardiologist to identify potentially ischemic stenosis for revascularization and nonculprit stenosis which can be deferred from stenting. An invasive coronary angiography and intravascular ultrasound provide anatomic information of stenosis severity whereas an invasive fractional flow reserve index (FFR) provides the functional significance of the stenosis severity. The measurement of functional significance of stenosis severity minimizes the procedural complications such as coronary dissection, in stent restenosis etc. rather than anatomical significance measure. The FFR cutoff value of [Formula: see text]0.8 is used to distinguish ischemic and nonischemic stenosis. The FFR is clinically well validated even though it is influenced by the mechanical factors such as hyperemic flow and guide wire insertion. In recent times, noninvasive coronary computed tomography (CCTA) modality has become popular in the diagnosis of coronary artery disease. The CCTA permits the assessment of cross-sectional parameters such as minimum lumen area and lumen diameter, lesion length and plaque morphology. However, the CCTA provides limited information on the functional significance of stenotic lesions as compared to FFR. The purpose of this review is to discuss the mechanical factors influencing the invasive FFR while assessing the functional significance of intermediate stenosis severity. In addition, the hidden mechanical factors influencing the noninvasive CCTA assessment of stenosis severity will be discussed from the critical information obtained from FFR which could be beneficial for the clinician particularly in the assessment of intermediate stenosis severity.
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Affiliation(s)
- KALIMUTHU GOVINDARAJU
- Ethiopian Institute of Technology, School of Mechanical and Industrial Engineering, Mekelle University, Mekelle, Ethiopia
| | | | | | - SIRAK AREGAWI WELDEMARIAM
- Ethiopian Institute of Technology, School of Mechanical and Industrial Engineering, Mekelle University, Mekelle, Ethiopia
| | - WOLDU ZINA GEBREHIWOT
- Ethiopian Institute of Technology, School of Mechanical and Industrial Engineering, Mekelle University, Mekelle, Ethiopia
| | - SARFARAZ KAMANGAR
- Department of Mechanical Engineering, University of Malaya, Malaysia
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Javadzadegan A, Yong ASC, Chang M, Ng MKC, Behnia M, Kritharides L. Haemodynamic assessment of human coronary arteries is affected by degree of freedom of artery movement. Comput Methods Biomech Biomed Engin 2016; 20:260-272. [DOI: 10.1080/10255842.2016.1215439] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Jia L, Wang L, Wei F, Yu H, Dong H, Wang B, Lu Z, Sun G, Chen H, Meng J, Li B, Zhang R, Bi X, Wang Z, Pang H, Jiang A. Effects of wall shear stress in venous neointimal hyperplasia of arteriovenous fistulae. Nephrology (Carlton) 2015; 20:335-42. [PMID: 25581663 DOI: 10.1111/nep.12394] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Lan Jia
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Lihua Wang
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Fang Wei
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Haibo Yu
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Hongye Dong
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Bo Wang
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Zhi Lu
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Guijiang Sun
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Haiyan Chen
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Jia Meng
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Bo Li
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Ruining Zhang
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Xueqing Bi
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Zhe Wang
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Haiyan Pang
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
| | - Aili Jiang
- Department of Kidney Disease and Blood Purification; Institute of Urology & Key Laboratory of Tianjin; The Second Hospital of Tianjin Medical University; Tianjin China
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Xiong H, Liu X, Tian X, Pu L, Zhang H, Lu M, Huang W, Zhang YT. A numerical study of the effect of varied blood pressure on the stability of carotid atherosclerotic plaque. Biomed Eng Online 2014; 13:152. [PMID: 25413300 PMCID: PMC4277844 DOI: 10.1186/1475-925x-13-152] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 10/22/2014] [Indexed: 12/18/2022] Open
Abstract
Background Blood pressure (BP) is associated with early atherosclerosis and plaque
rupture because the BP variability can significantly affect the blood flow
velocity and shear stress over the plaque. However, the mechanical response of BP
variability to the plaque remains unclear. Therefore, we investigated the
correlation between different maximum systolic blood pressure (SBP) and the stress
distribution on plaque, as well as the stress over the plaque and blood velocity
around the plaque using different BP variations, which are the BP variability in
different phases during one cardiac cycle and beat-to-beat BP variability. Method We established a two-dimensional artery model with stenosis at the degree of
62.5%. Eight combinations of pulsatile pressure gradients between the inflow and
outflow were implemented at the model. Three levels of fibrous cap thickness were
taken into consideration to investigate the additional effect on the BP
variability. Wall shear stress and stress/strain distribution over the plaque were
derived as well as the oscillation shear index (OSI) to analyze the impact of the
changing rate of BP. Result The stresses at diastole were 2.5% ± 1.8% lower than that at systole under the
same pressure drop during one cycle. It was also found that elevated SBP might
cause the immediate increment of stress in the present cycle (292% ± 72.3%), but
slight reduction in the successive cycle (0.48% ± 0.4%). Conclusion The stress/strain distribution over the plaque is sensitive to the BP
variability during one cardiac cycle, and the beat-to-beat BP variability could
cause considerable impact on the progression of atherosclerosis in
long-term.
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Affiliation(s)
| | | | | | | | - Heye Zhang
- Key Lab of Health Informatics of Chinese Academy of Sciences, Shenzhen, China.
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Can sites prone to flow induced vascular complications in a-v fistulas be assessed using computational fluid dynamics? J Biomech 2010; 43:2002-9. [DOI: 10.1016/j.jbiomech.2010.02.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 02/19/2010] [Accepted: 02/24/2010] [Indexed: 11/21/2022]
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