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Targeted drug delivery of magnetic microbubble for abdominal aortic aneurysm: an in silico study
, Article Biomechanics and Modeling in Mechanobiology ; Volume 21, Issue 2 , 2022 , Pages 735-753 ; 16177959 (ISSN) ; Ebrahimi, S ; Ghorbani, G ; Alishiri, M ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
Targeted drug delivery (TDD) to abdominal aortic aneurysm (AAA) using a controlled and efficient approach has recently been a significant challenge. In this study, by using magnetic microbubbles (MMBs) under a magnetic field, we investigated the MMBs performance in TDD to AAA based on the amount of surface density of MMBs (SDMM) adhered to the AAA lumen. The results showed that among the types of MMBs studied in the presence of the magnetic field, micromarkers are the best type of microbubble with a −50 % increase in SDMM adhered to the critical area of AAA. The results show that applying a magnetic field causes the amount of SDMM adhered to the whole area of AAA to increase −1.54 times...
Investigation of coronary artery tortuosity with atherosclerosis: A study on predicting plaque rupture and progression
, Article International Journal of Mechanical Sciences ; Volume 223 , 2022 ; 00207403 (ISSN) ; Fallah, F ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
This study investigated the effects of different patterns of coronary artery tortuosity (CAT) on the stress concentration of the plaques and the blood flow pattern inside an atherosclerotic artery to predict the risk of plaque rupture and progression. Four different loadings of the coronary artery, including pulsatile blood pressure as well as one-end twist around the artery axis at blood pressures of 74, 100, and 120 mmHg were considered. No study has addressed bent and twist buckling of an atherosclerotic artery considering pulsatile flow (for bent buckling), fluid-solid interaction, and different geometrical parameters of the plaque. The results showed that C-shape tortuosity under...
Patient-specific fluid–structure interaction simulation of the LAD-ITA bypass graft for moderate and severe stenosis: A doubt on the fractional flow reserve-based decision
, Article Biocybernetics and Biomedical Engineering ; Volume 42, Issue 1 , 2022 , Pages 143-157 ; 02085216 (ISSN) ; Firoozabadi, B ; Pakravan, H. A ; Ahmadi Tafti, S. H ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Fractional flow reserve (FFR)-based decision improves the outcomes of percutaneous coronary intervention (PCI) for some patients, while its effectiveness in improving the results of coronary artery bypass graft (CABG) is unclear, in particular for moderate stenosis. It may be due to the fact that FFR cannot take into account the impacts of competitive flow (CF), intimal hyperplasia (IH), as well as compliance mismatch (CMM). As a result, two questions arise 1) whether FFR is a sufficient factor to decide to perform the CABG for patients with moderate to severe stenosis or not and 2) whether post-operative FFR shows the effectiveness of a graft. To shed light on this matter, two...
Atheroprone sites of coronary artery bifurcation: Effect of heart motion on hemodynamics-dependent monocytes deposition
, Article Computers in Biology and Medicine ; Volume 133 , 2021 ; 00104825 (ISSN) ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Atherosclerosis as a common cardiovascular disease is a result of both adverse hemodynamics conditions and monocyte deposition within coronary arteries. It is known that the adhesion of monocytes on the arterial wall and their interaction with the vascular surface are one of the main parameters in the initiation and progression of atherosclerosis. In this work, hemodynamic parameters and monocyte deposition have been investigated in a 3D computational model of the Left Anterior Descending coronary artery (LAD) and its first diagonal branch (D1) under the heart motion. A one-way Lagrangian approach is performed to trace the monocyte particles under different blood flow regimes and heart motion...
Drug delivery performance of nanocarriers based on adhesion and interaction for abdominal aortic aneurysm treatment
, Article International Journal of Pharmaceutics ; Volume 594 , 2021 ; 03785173 (ISSN) ; Vatani, P ; Amani, A ; Shamloo, A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Targeted drug delivery using nanocarriers (NCs) is one of the novel techniques that has recently been used to improve drug delivery to the Abdominal aortic aneurysm (AAA) disease. The purpose of this study is to evaluate the surface density of NCs (SDNC) adhered via ligand-receptor binding to the inner wall of AAA. For this purpose, fluid–structure interaction (FSI) analysis was first performed for the patient-specific and ideal AAA models. Then, by injecting NCs into the aortic artery, the values of SDNC adhered to and interacted with AAA wall were obtained. Two types of NCs, liposomes, and solid particles in four different diameters, were used to investigate the effect of the diameter and...
Artificial neural network for predicting the safe temporary artery occlusion time in intracranial aneurysmal surgery
, Article Journal of Clinical Medicine ; Volume 10, Issue 7 , 2021 ; 20770383 (ISSN) ; Ghodsi, S. M ; Zangeneh Soroush, M ; Ansari, S ; Kamali Ardakani, S ; Sharif University of Technology
MDPI
2021
Abstract
Background. Temporary artery clipping facilitates safe cerebral aneurysm management, besides a risk for cerebral ischemia. We developed an artificial neural network (ANN) to predict the safe clipping time of temporary artery occlusion (TAO) during intracranial aneurysm surgery. Method. We devised a three-layer model to predict the safe clipping time for TAO. We considered age, the diameter of the right and left middle cerebral arteries (MCAs), the diameter of the right and left A1 segment of anterior cerebral arteries (ACAs), the diameter of the anterior communicating artery, mean velocity of flow at the right and left MCAs, and the mean velocity of flow at the right and left ACAs, as well...
Effects of Brownian motions and thermophoresis diffusions on the hematocrit and LDL concentration/diameter of pulsatile non-Newtonian blood in abdominal aortic aneurysm
, Article Journal of Non-Newtonian Fluid Mechanics ; Volume 294 , 2021 ; 03770257 (ISSN) ; Esfahani, A. N ; Golab, E ; Golestanian, O ; Ashouri, N ; Sajadi, S. M ; Ghaemi, F ; Baleanu, D ; Karimipour, A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
LDL concentration is believed to be responsible for plaque formation that leads to atherosclerotic cardiovascular disease. We conducted this study to investigate the effects of hematocrits and LDL diameters on LDL concentration on the wall of an abdominal aortic aneurysm (AAA). The blood flow was considered to be a pulsatile and non-Newtonian flow whose viscosity was a function of hematocrits and strain rate. Lumen, Brownian, and thermophoresis diffusions were analyzed in LDL concentration. The results demonstrated that adding thermophoresis diffusion increases LDL concentration. Moreover, among three types of LDLs, including small LDLs, intermediate LDLs, and large LDLs, small LDLs were the...
Effects of Brownian motions and thermophoresis diffusions on the hematocrit and LDL concentration/diameter of pulsatile non-Newtonian blood in abdominal aortic aneurysm
, Article Journal of Non-Newtonian Fluid Mechanics ; Volume 294 , 2021 ; 03770257 (ISSN) ; Esfahani, A. N ; Golab, E ; Golestanian, O ; Ashouri, N ; Sajadi, S. M ; Ghaemi, F ; Baleanu, D ; Karimipour, A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
LDL concentration is believed to be responsible for plaque formation that leads to atherosclerotic cardiovascular disease. We conducted this study to investigate the effects of hematocrits and LDL diameters on LDL concentration on the wall of an abdominal aortic aneurysm (AAA). The blood flow was considered to be a pulsatile and non-Newtonian flow whose viscosity was a function of hematocrits and strain rate. Lumen, Brownian, and thermophoresis diffusions were analyzed in LDL concentration. The results demonstrated that adding thermophoresis diffusion increases LDL concentration. Moreover, among three types of LDLs, including small LDLs, intermediate LDLs, and large LDLs, small LDLs were the...
The effect of hematocrit and nanoparticles diameter on hemodynamic parameters and drug delivery in abdominal aortic aneurysm with consideration of blood pulsatile flow
, Article Computer Methods and Programs in Biomedicine ; Volume 195 , October , 2020 ; Nasiri Sadr, A ; Kaffash, E ; Goudarzi, S ; Golab, E ; Karimipour, A ; Sharif University of Technology
Elsevier Ireland Ltd
2020
Abstract
Background and Objective: The present article has simulated to investigate the efficient hemodynamic parameters, the drug persistence, and drug distribution on an abdominal aortic aneurysm. Methods: Blood as a non-Newtonian fluid enters the artery acting as a real pulse waveform; its behavior is dependent on hematocrit and strain rate. In this simulation of computational fluid dynamic, magnetic nanoparticles of iron oxide which were in advance coated with the drug, are injected into the artery during a cardiac cycle. A two-phase model was applied to investigate the distribution of these carriers. Results: The results are presented for different hematocrits and the nanoparticle diameter. It...
Numerical study of the effect of vascular bed on heat transfer during high intensity focused ultrasound (HIFU) ablation of the liver tumor
, Article Journal of Thermal Biology ; Volume 86 , 2019 ; 03064565 (ISSN) ; Firoozabadi, B ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
In this study, the influence of vascular bed comprising terminal arterial branches on heat transfer in a liver tumor exposed to high intensity focused ultrasound (HIFU) is studied numerically. Also, the effect of vascular density on temperature distribution is investigated. A coupled set of acoustics, thermal, and fluid models is used to calculate the temperature distribution in the liver. The numerical model is established based on the Westervelt and bioheat equations along with the Navier-Stokes equations. Moreover, the acoustic streaming effect is included with Newtonian and non-Newtonian flow assumptions. It is found that in a vascular bed comprising terminal arterial branches, the...
Fluid-structure interaction simulation of blood flow and cerebral aneurysm: effect of partly blocked vessel
, Article Journal of Vascular Research ; Volume 56, Issue 6 , 2019 , Pages 296-307 ; 10181172 (ISSN) ; Shamloo, A ; Mohammadi, A ; Sharif University of Technology
S. Karger AG
2019
Abstract
In this study, using fluid-structure interaction (FSI), 3-dimensional blood flow in an aneurysm in the circle of Willis-which is located in the middle cerebral artery (MCA)-has been simulated. The purpose of this study is to evaluate the effect of a partly blocked vessel on an aneurysm. To achieve this purpose, two cases have been investigated using the FSI method: in the first case, an ideal geometry of aneurysm in the MCA has been simulated; in the second case, modeling is performed for an ideal geometry of the aneurysm in the MCA with a partly blocked vessel. All boundary conditions, properties and modeling methods were considered the same for both cases. The only difference between the...
In silico study of patient-specific magnetic drug targeting for a coronary LAD atherosclerotic plaque
, Article International Journal of Pharmaceutics ; Volume 559 , 2019 , Pages 113-129 ; 03785173 (ISSN) ; Amani, A ; Forouzandehmehr, M ; Ghoytasi, I ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Coronary artery disease is the first cause of death across the world. Targeted delivery of therapeutics through controlled release of micro- and nano-particles remains a very capable approach to develop new strategies in treating restenosis and atherosclerotic plaques. In this research, to produce the arterial geometry, an image-processing was done using CT-scan images of a LAD coronary artery. After implementing the finite element mesh, the Fluid-Structure Interaction (FSI) simulation based on physiological boundary conditions was performed. Next, a Lagrangian description of particles dynamics in a non-Newtonian blood flow considering momentum equation of motion for each particle and the...
Design of a broadband high frequency ultrasound transducer for skin imaging
, Article 6th RSI International Conference on Robotics and Mechatronics, IcRoM 2018, 23 October 2018 through 25 October 2018 ; 2019 , Pages 261-265 ; 9781728101279 (ISBN) ; Chabok, H. R ; Nejat, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
This paper discusses the design of a high frequency wide bandwidth ultrasound transducer with the center frequency of 50 MHz and an aperture diameter of 3 mm for medical ultrasonic imaging. The piezoelectric material used in this design is Lithium Niobate. The design is verified by both KLM equivalent circuit and spatial impulse response method as used in FIELD II software and the theoretical imaging resolution has been calculated as 50 um axially and 80 um laterally. The possible applications of this probe are skin layer imaging, tumor detection and superficial blood flow measurement
Margination and adhesion of micro- and nanoparticles in the coronary circulation: A step towards optimised drug carrier design
, Article Biomechanics and Modeling in Mechanobiology ; Volume 17, Issue 1 , 2018 , Pages 205-221 ; 16177959 (ISSN) ; Shamloo, A ; Sharif University of Technology
Springer Verlag
2018
Abstract
Obstruction of left anterior descending artery (LAD) due to the thrombosis or atherosclerotic plaques is the leading cause of death worldwide. Targeted delivery of drugs through micro- and nanoparticles is a very promising approach for developing new strategies in clot-busting or treating restenosis. In this work, we modelled the blood flow characteristics in a patient-specific reconstructed LAD artery by the fluid–solid interaction method and based on physiological boundary conditions. Next, we provided a Lagrangian description of micro- and nanoparticles dynamics in the blood flow considering their Brownian motion and the particle–particle interactions. Our results state that the number of...
Pulsatile blood flow in total cavopulmonary connection: a comparison between Y-shaped and T-shaped geometry
, Article Medical and Biological Engineering and Computing ; Volume 55, Issue 2 , 2017 , Pages 213-224 ; 01400118 (ISSN) ; Firoozabadi, B ; Saidi, M. S ; Monjezi, M ; Navabi Shirazi, M. A ; Malakan Rad, E ; Sharif University of Technology
Springer Verlag
2017
Abstract
Single-ventricle anomaly is a hereditary heart disease that is characterized by anatomical malformations. The main consequence of this malformation is desaturated blood flow, which without proper treatment increases the risk of death. The classical treatment is based on a three-stage palliative procedure which should begin from the first few days of patient’s life. The final stage is known as Fontan procedure, in which inferior vena cava is directly connected to pulmonary arteries without going through the ventricle. This connection is called total cavopulmonary connection (TCPC). After surgery, the single ventricle supplies adequate and saturated systemic blood flow to the body; however,...
Mathematical study of probe arrangement and nanoparticle injection effects on heat transfer during cryosurgery
, Article Computers in Biology and Medicine ; Volume 66 , Nov , 2015 , Pages 113-119 ; 00104825 (ISSN) ; Ramazani S. A. A ; Nazemidashtarjandi, S ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Blood vessels, especially large vessels have a greater thermal effect on freezing tissue during cryosurgery. Vascular networks act as heat sources in tissue, and cause failure in cryosurgery and reappearance of cancer. The aim of this study is to numerically simulate the effect of probe location and multiprobe on heat transfer distribution. Furthermore, the effect of nanoparticles injection is studied. It is shown that the small probes location near large blood vessels could help to reduce the necessary time for tissue freezing. Nanoparticles injection shows that the thermal effect of blood vessel in tissue is improved. Using Au, Ag and diamond nanoparticles have the most growth of ice ball...
Evaluation of a novel extra-cardiac Fontan procedure with implantation of a biocompatible membrane
, Article IRBM ; Volume 36, Issue 5 , 2015 , Pages 287-292 ; 19590318 (ISSN) ; Firoozabadi, B ; Saidi, M. S ; Monjezi, M ; Navabi Shirazi, M. A ; Malakan Rad, E ; Sharif University of Technology
Elsevier Masson SAS
2015
Abstract
Fontan operation is a final palliative surgical treatment for patients with a single ventricle (SV) physiology. One of the common disadvantages of Fontan operation is to generate a non-pulsatile flow instead of the normal pulsatile flow produced by contraction of the ventricle. Theoretically, in SV patients, maintaining the antegrade flow through pulmonary valve can produce flow pulsatility in the right and left pulmonary arteries. However, it not only increases the energy loss in the Fontan of total cavopulmonary pathway (TCPC), but also imposes an extra load on pulmonary arteries as well as the ventricle. In this study, the potential capability of pulmonary valve of the patient that can be...
Analytical and numerical evaluation of steady flow of blood through artery
, Article Biomedical Research (India) ; Volume 24, Issue 1 , 2013 , Pages 88-98 ; 0970938X (ISSN) ; Barari, A ; Soleimani, S ; Mofidi, M ; Sharif University of Technology
2013
Abstract
Steady blood flow through a circular artery with rigid walls is studied by COSSERAT Continuum Mechanical Approach. To obtain the additional viscosities coefficients, feed forward multi-layer perceptron (MLP) type of artificial neural networks (ANN) and the results obtained in previous empirical works is used. The governing filed equations are derived and solution to the Hagen-Poiseuilli flow of a COSSERAT fluid in the artery is obtained analytically by Homotopy Perturbation Method (HPM) and numerically using finite difference method. Comparison of analytical results with numerical ones showed excellent agreement. In addition microrotation and the velocity profile along the radius are...
Numerical modeling of pulsating inflow to the pulmonary arteries in TCPC morphology using FSI approach
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) ; Volume 3 A , 2013 ; 9780791856215 (ISBN) ; Firoozabadi, B ; Saidi, M. S ; Sohrabi, S ; Mehr, S. M. N ; Sharif University of Technology
2013
Abstract
The Fontan surgery is performed on patients with a single ventricle heart defect to prevent the combination of highlyoxygenated and poorly-oxygenated blood. Blood flow in total cavopulmonary connection (TCPC) which culminates an ordinary Fontan operation is practically steady-state but this flow is not appropriate for respiratory systems. This article investigates an approach in Fontan surgery that has been recently proposed in order to make the pulmonary blood flow pulsating. Moreover, for investigating the compliance of vessels and its effects on blood flow in TCPC, we have used the FSI (Fluid Structure Interaction) method as well as rigid wall assumption for comparison purposes. Our TCPC...
Introducing an adaptive robust controller for artificial heart
, Article Proceedings of the IEEE RAS and EMBS International Conference on Biomedical Robotics and Biomechatronics, 24 June 2012 through 27 June 2012 ; June , 2012 , Pages 413-418 ; 21551774 (ISSN) ; 9781457711992 (ISBN) ; Jahed, M ; Sharif University of Technology
2012
Abstract
Prolonged and uncontrolled high shear stresses and turbulence can cause hemolysis, while alternating and low-level stresses may contribute to platelet activation and thrombus formation. Such deficiencies are reported for Total Artificial Heart (TAH) systems which are generally not fully capable of dynamic adaptation to sudden pressure and volume changes. This study introduces an adaptive robust controller for a linear motor based TAH (LMTAH) which overcomes such shortcomings. Proposed controller performance is compared with simulated natural heart in normal and stressed physiological conditions. Application of adaptive robust control results in flows with less stress variation and...