Search for: cardiovascular-disease
A numerical study of the effects of blood rheology and vessel deformability on the hemodynamics of carotid bifurcation, Article Scientia Iranica ; Volume 19, Issue 1 , February , 2012 , Pages 119-125 ; 10263098 (ISSN) ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
Hemodynamic factors, such as Wall Shear Stress (WSS), play a substantial role in arterial diseases. In the larger arteries, such as the carotid artery, interaction between the vessel wall and blood flow affects the distribution of hemodynamic factors. In the present study, both rigid-wall and deformable-wall models are developed in a 3D numerical simulation to assess the effectiveness of arterial rigidity on worsening hemodynamics, especially WSS. Two different rheological models (Newtonian and CarreauYasuda) have been employed to evaluate the influence of blood, non-Newtonian properties, as well. The importance of vessel wall deformability was compared with the rheological model of blood....
Synthetic ECG generation and bayesian filtering using a Gaussian wave-based dynamical model, Article Physiological Measurement ; Volume 31, Issue 10 , 2010 , Pages 1309-1329 ; 09673334 (ISSN) ; Shamsollahi, M. B ; Clifford, G. D ; Sharif University of Technology
In this paper, we describe a Gaussian wave-based state space to model the temporal dynamics of electrocardiogram (ECG) signals. It is shown that this model may be effectively used for generating synthetic ECGs as well as separate characteristic waves (CWs) such as the atrial and ventricular complexes. The model uses separate state variables for each CW, i.e. P, QRS and T, and hence is capable of generating individual synthetic CWs as well as realistic ECG signals. The model is therefore useful for generating arrhythmias. Simulations of sinus bradycardia, sinus tachycardia, ventricular flutter, atrial fibrillation and ventricular tachycardia are presented. In addition, discrete versions of...
A clinical decision support system based on support vector machine and binary particle swarm optimisation for cardiovascular disease diagnosis, Article International Journal of Data Mining and Bioinformatics ; Volume 15, Issue 4 , 2016 , Pages 312-327 ; 17485673 (ISSN) ; Shavandi, H ; Sadeghi, M ; Sharif University of Technology
Inderscience Enterprises Ltd 2016
Cardiovascular diseases have been known as one of the main reasons of mortality all around the world. Nevertheless, this disease is preventable if it can be diagnosed in an early stage. Therefore, it is crucial to develop Clinical Decision Support Systems (CDSSs) that are able to help physicians diagnose the disease and its related risks. This study focuses on cardiovascular disease diagnosis in an Iranian community by developing a CDSS, based on Support Vector Machine (SVM) combined with Binary Particle Swarm Optimisation (BPSO). We used SVM as the classifier and benefited enormously from optimisation capabilities of BPSO in model development as well as feature selection. Finally,...
Multifunctional conductive biomaterials as promising platforms for cardiac tissue engineering, Article ACS Biomaterials Science and Engineering ; Volume 7, Issue 1 , 2021 , Pages 55-82 ; 23739878 (ISSN) ; Vahdat, S ; Baheiraei, N ; Razavi, M ; Norahan, M. H ; Baharvand, H ; Sharif University of Technology
American Chemical Society 2021
Adult cardiomyocytes are terminally differentiated cells that result in minimal intrinsic potential for the heart to self-regenerate. The introduction of novel approaches in cardiac tissue engineering aims to repair damages from cardiovascular diseases. Recently, conductive biomaterials such as carbon- and gold-based nanomaterials, conductive polymers, and ceramics that have outstanding electrical conductivity, acceptable mechanical properties, and promoted cell-cell signaling transduction have attracted attention for use in cardiac tissue engineering. Nevertheless, comprehensive classification of conductive biomaterials from the perspective of cardiac cell function is a subject for...
A validated reduced-order dynamic model of nitric oxide regulation in coronary arteries, Article Computers in Biology and Medicine ; Volume 139 , 2021 ; 00104825 (ISSN) ; Tajeddini, F ; Pakravan, H. A ; Mahzoon, M ; Azadi Yazdi, E ; Bazrafshan Drissi, H ; Sharif University of Technology
Elsevier Ltd 2021
Nitric Oxide (NO) provides myocardial oxygen demands of the heart during exercise and cardiac pacing and also prevents cardiovascular diseases such as atherosclerosis and platelet adhesion and aggregation. However, the direct in vivo measurement of NO in coronary arteries is still challenging. To address this matter, a mathematical model of dynamic changes of calcium and NO concentration in the coronary artery was developed for the first time. The model is able to simulate the effect of NO release in coronary arteries and its impact on the hemodynamics of the coronary arterial tree and also to investigate the vasodilation effects of arteries during cardiac pacing. For these purposes, flow...
An optimum design and simulation of an innovative mobile robotic nurse unit to assist paraplegic patients, Article Proceedings of the IEEE International Conference on Mechatronics 2004, ICM'04, Istanbul, 3 June 2004 through 5 June 2004 ; 2004 , Pages 141-147 ; 0780385993 (ISBN) ; Hosseinkhannazer, H ; Selkghafari, A ; Sharif University of Technology
This paper describes a nursing robot system currently under development at the Center of Excellence in Design, Robotics and Automation. Our goal was to design and fabricate of a robot specifically for paraplegic patients and the design procedure led to a plan which can be employed in any hospital environment. Through the design procedure, the team members conducted a survey on the robot client's needs and disabilities which provided a unique view on mechanical design features, in addition to, performing dynamical analysis on the designed mechanisms. Dynamical Simulation of mechanisms helped us to find the best design and solutions as well as optimization of parts has resulted in a matchless...
Low back pain and postural sway during quiet standing with and without sensory manipulation: A systematic review, Article Gait and Posture ; Volume 37, Issue 1 , 2013 , Pages 12-22 ; 09666362 (ISSN) ; Coenen, P ; Parnianpour, M ; Kiers, H ; van Dieen, J. H ; Sharif University of Technology
A previous review concluded that postural sway is increased in patients with low back pain (LBP). However, more detailed analysis of the literature shows that postural deficit may be dependent on experimental conditions in which patients with LBP have been assessed. The research question to be answered in this review was: " Is there any difference in postural sway between subjects with and without LBP across several sensory manipulation conditions?" A literature search in Pubmed, Scopus, Embase and PsychInfo was performed followed by hand search and contact with authors. Studies investigating postural sway during bipedal stance without applying external forces in patients with specific and...
Investigation of wall shear stress related factors in realistic carotid bifurcation geometries and different flow conditions, Article Scientia Iranica ; Volume 17, Issue 5 B , 2010 , Pages 358-366 ; 10263098 (ISSN) ; Jafarnejad, M ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
Cardiovascular diseases are one of the major causes of death in the world; atherosclerosis being one aspect. Carotid bifurcation is one of the sites that are vulnerable to this disease. Wall Shear Stress (WSS) is known to be responsible for the process of atherogenesis. In this study, we have simulated the blood flow for Newtonian and non-Newtonian, steady and unsteady, flow conditions in three idealistic and five realistic geometries. A risk factor has been presented based on the results of wall shear stress and, then, a relation was found between geometrical features and the wall shear stress risk factor. Our main conclusions are: 1) The non-Newtonian behavior of blood elevates the value...
Definition and comparison of a new vascular index between young healthy and aged subjects, Article IECBES 2014, Conference Proceedings - 2014 IEEE Conference on Biomedical Engineering and Sciences: "Miri, Where Engineering in Medicine and Biology and Humanity Meet", 8 December 2014 through 10 December 2014 ; 2015 , Pages 911-915 ; 9781479940844 (ISBN) ; Zahedi, E ; Mohd Ali, M. A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2015
In an effort to identify a useful noninvasive screening tool for cardiovascular diseases (CVD) screening, photoplethysmograph (PPG) signals were acquired and analyzed. These PPG signals were recorded during reactive hyperemia experiments consisting of a 4-minute blood flow blockage of the right arm (RA) brachial artery (BA) using a blood pressure cuff inflator. This procedure is usually done for the assessment of endothelial dysfunction which is a risk factor for developing CVD. In this study, signals of the infrared (IR) and red (R) LED's of the PPG sensor were analyzed. These signals were preprocessed, normalized and slow varying component of the signal (DC values) and the pulsatile...
Healthy and diseasedin vitromodels of vascular systems, Article Lab on a Chip ; Volume 21, Issue 4 , 2021 , Pages 641-659 ; 14730197 (ISSN) ; Mallone, A ; Nasrollahi, F ; Ostrovidov, S ; Nasiri, R ; Mahmoodi, M ; Haghniaz, R ; Baidya, A ; Salek, M. M ; Darabi, M. A ; Orive, G ; Shamloo, A ; Dokmeci, M. R ; Ahadian, S ; Khademhosseini, A ; Sharif University of Technology
Royal Society of Chemistry 2021
Irregular hemodynamics affects the progression of various vascular diseases, such atherosclerosis or aneurysms. Despite the extensive hemodynamics studies on animal models, the inter-species differences between humans and animals hamper the translation of such findings. Recent advances in vascular tissue engineering and the suitability ofin vitromodels for interim analysis have increased the use ofin vitrohuman vascular tissue models. Although the effect of flow on endothelial cell (EC) pathophysiology and EC-flow interactions have been vastly studied in two-dimensional systems, they cannot be used to understand the effect of other micro- and macro-environmental parameters associated with...
Classification of vascular function in upper limb using bilateral photoplethysmographic signals, Article Physiological Measurement ; Volume 29, Issue 3 , 2008 , Pages 365-374 ; 09673334 (ISSN) ; Zahedi, E ; Jajai, H. M ; Sharif University of Technology
Bilateral PPG signals have been used for comparative study of two groups of healthy (free from any cardiovascular risk factors) and diabetic (as cardiovascular disease risk group) subjects in the age-matched range 40-50 years. The peripheral blood pulsations were recorded simultaneously from right and left index fingers for 90 s. Pulses have been modeled with the ARX440 model in the interval of 300 sample points with 100 sample points overlap between segments. Model parameters of three segments based on the highest fitness (higher than 80%) of modeled segments were retained for each subject. Subsequently, principal component analysis (PCA) was applied to the parameters of retained segments...
Short-term effects of particle size fractions on circulating biomarkers of inflammation in a panel of elderly subjects and healthy young adults, Article Environmental Pollution ; Volume 223 , 2017 , Pages 695-704 ; 02697491 (ISSN) ; Naddafi, K ; Kashani, H ; Faridi, S ; Kunzli, N ; Nabizadeh, R ; Momeniha, F ; Gholampour, A ; Arhami, M ; Zare, A ; Pourpak, Z ; Hoseini, M ; Yunesian, M ; Sharif University of Technology
Systemic inflammation biomarkers have been associated with risk of cardiovascular morbidity and mortality. We aimed to clarify associations of acute exposure to particulate matter (PM10(PM < 10 μm), PM2.5-10(PM 2.5–10 μm), PM2.5(PM < 2.5 μm), PM1-2.5(PM 1–2.5 μm), and PM1 (PM < 1 μm)) with systemic inflammation using panels of elderly subjects and healthy young adults. We followed a panel of 44 nonsmoking elderly subjects living in a retirement home and a panel of 40 healthy young adults living in a school dormitory in Tehran city, Iran from May 2012 to May 2013. Blood biomarkers were measured one every 7–8 weeks and included white blood cells (WBC), high sensitive C-reactive protein...
Iran in transition, Article The Lancet ; Volume 393, Issue 10184 , 2019 , Pages 1984-2005 ; 01406736 (ISSN) ; Farzadfar, F ; Kelishadi, R ; Rashidian, A ; Rouhani, O. M ; Ahmadnia, S ; Ahmadvand, A ; Arabi, M ; Ardalan, A ; Arhami, M ; Azizi, M. H ; Bahadori, M ; Baumgartner, J ; Beheshtian, A ; Djalalinia, S ; Doshmangir, L ; Haghdoost, A. A ; Haghshenas, R ; Hosseinpoor, A. R ; Islami, F ; Kamangar, F ; Khalili, D ; Madani, K ; Masoumi Asl, H ; Mazyaki, A ; Mirchi, A ; Moradi, E ; Nayernouri, T ; Niemeier, D ; Houshang Omidvari, A ; Peykari, N ; Pishgar, F ; Qorbani, M ; Rahimi, K ; Rahimi Movaghar, A ; Ramezani Tehrani, F ; Rezaei, N ; Shahraz, S ; Takian, A ; Tootee, A ; Ezzati, M ; Jamshidi, H. R ; Larijani, B ; Majdzadeh, R ; Malekzadeh, R ; Sharif University of Technology
Lancet Publishing Group 2019
Being the second-largest country in the Middle East, Iran has a long history of civilisation during which several dynasties have been overthrown and established and health-related structures have been reorganised. Iran has had the replacement of traditional practices with modern medical treatments, emergence of multiple pioneer scientists and physicians with great contributions to the advancement of science, environmental and ecological changes in addition to large-scale natural disasters, epidemics of multiple communicable diseases, and the shift towards non-communicable diseases in recent decades. Given the lessons learnt from political instabilities in the past centuries and the...
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
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...
Computer aided decision making for heart disease detection using hybrid neural network-Genetic algorithm, Article Computer Methods and Programs in Biomedicine ; Volume 141 , 2017 , Pages 19-26 ; 01692607 (ISSN) ; Alizadehsani, R ; Roshanzamir, M ; Moosaei, H ; Yarifard, A. A ; Sharif University of Technology
Elsevier Ireland Ltd 2017
Cardiovascular disease is one of the most rampant causes of death around the world and was deemed as a major illness in Middle and Old ages. Coronary artery disease, in particular, is a widespread cardiovascular malady entailing high mortality rates. Angiography is, more often than not, regarded as the best method for the diagnosis of coronary artery disease; on the other hand, it is associated with high costs and major side effects. Much research has, therefore, been conducted using machine learning and data mining so as to seek alternative modalities. Accordingly, we herein propose a highly accurate hybrid method for the diagnosis of coronary artery disease. As a matter of fact, the...