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Total 159 records

    The dilemma of BME research projects in developing countries: a case study

    , Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference ; Volume 2011 , 2011 , Pages 3631-3635 ; 1557170X (ISSN) Zahedi, E ; Attar, H. M ; Sharif University of Technology
    2011
    Abstract
    Researchers are faced with huge challenges when undertaking BME research projects in developing countries. Various administrative, technical, economic and even cultural barriers have to be overcome whereas the quality and quantity of the output has to be comparable with the developed world in order to make results publishable. This paper uses a real project context to highlight the major problems and the necessity of a holistic approach which would take into consideration all stakeholders interests. It is only by tackling problems such as relationship between academia-industry and administration efficiency at their root that significant progress can be achieved  

    A new approach for touching cells segmentation

    , Article BioMedical Engineering and Informatics: New Development and the Future - 1st International Conference on BioMedical Engineering and Informatics, BMEI 2008, Sanya, Hainan, 27 May 2008 through 30 May 2008 ; Volume 1 , 2008 , Pages 816-820 ; 9780769531182 (ISBN) Nasr Isfahani, S ; Mirsafian, A ; Masoudi Nejad, A ; Sharif University of Technology
    2008
    Abstract
    Automatic cell segmentation has various applications in different parts of science. The development of automated methods for cell segmentation, remains challenging in situations where there are touching cells. In this paper we propose a new method for separating touching cells. As the first step, we use a combination of graph segmentation algorithm and thresholding for segmenting foreground objects and producing a binary image. Next, boundary points of separation zone are selected by using a corner detection algorithm. Finally, the marker controller watershed transform is applied to separate touching cells at selected points. © 2008 IEEE  

    A simple and fast analysis of SNR in non-coherent integrators

    , Article 2005 1st International Conference on Computers, Communications and Signal Processing with Special Track on Biomedical Engineering, CCSP 2005, Kuala Lumpur, 14 November 2005 through 16 November 2005 ; 2005 , Pages 5-9 ; 1424400112 (ISBN); 9781424400119 (ISBN) Esfandyarpour, R ; Norouzi, Y ; Parizi, K. B ; Esfandyarpour, H ; Nayebi, M. M ; Sharif University of Technology
    2005
    Abstract
    In this paper, an approximate analysis for SNR improvement factor in non-coherent integrators for communication channels is introduced. The SNR improvement factor and loss function of the non-coherent integrator are calculated. Our results are very simple and illustrative. Although calculations are with some approximations and therefore the results are not exact, but the error is negligible, as it is shown. © 2005 IEEE  

    New image-based system for vibration measurment, specially developed for forced human vibration analysis

    , Article 2004 ASME International Mechanical Engineering Congress and Exposition, IMECE, Anaheim, CA, 13 November 2004 through 19 November 2004 ; 2004 , Pages 203-204 ; 03609960 (ISSN) Hoviattalab, M ; Yadolahi, A ; Narimani, R ; Abadpour, A ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2004
    Abstract
    The human being in the environments of modern technology has to endure stresses of many and varied kinds of vibrations. Measuring vibration is an important tool in rehabilitation and biomechanical fields of research. We have proposed image processing as a new method to record and determine the frequency response of human body. The subjects were exposed to whole body periodical vibration while standing on a shaking table. Two digital camcorders were used to capture the motion of colored pencil-dot markers on the skin of human body (forehead) and on the edge of the shaking table. After color spotting each frame, the binary image results were processed using new circle factor criteria proposed... 

    Curcumin sustained release with a hybrid chitosan-silk fibroin nanofiber containing silver nanoparticles as a novel highly efficient antibacterial wound dressing

    , Article Nanomaterials ; Volume 12, Issue 19 , 2022 ; 20794991 (ISSN) Heydari Foroushani, P ; Rahmani, E ; Alemzadeh, I ; Vossoughi, M ; Pourmadadi, M ; Rahdar, A ; Díez Pascual, A. M ; Sharif University of Technology
    MDPI  2022
    Abstract
    Drug loading in electrospun nanofibers has gained a lot of attention as a novel method for direct drug release in an injury site to accelerate wound healing. The present study deals with the fabrication of silk fibroin (SF)-chitosan (CS)-silver (Ag)-curcumin (CUR) nanofibers using the electrospinning method, which facilitates the pH-responsive release of CUR, accelerates wound healing, and improves mechanical properties. Response surface methodology (RSM) was used to investigate the effect of the solution parameters on the nanofiber diameter and morphology. The nanofibers were characterized via Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron... 

    Validation of the Saadat NIBP module according to the ANSI/AAMI-SP10 protocol

    , Article 2013 20th Iranian Conference on Biomedical Engineering, ICBME 2013 ; Deembec , 2013 , Pages 199-202 Sadaghiani, M ; Mashayekhi, G ; Behzadfar, N ; Yaghoobzadeh, A ; Babaee, T ; Sharif University of Technology
    IEEE Computer Society  2013
    Abstract
    This study is conducted with the aim of validating the Saadat non-invasive blood pressure (NIBP) module accuracy and reliability against direct intra arterial pressure measurement (IBP) according to the ANSI/AAMI SP10-2002 guidelines. Measurement and comparison procedure were done in a static population of 19 adult patients with brachial catheterized arterial line with total measurements of 195 under supervision of a highly experienced cardiovascular anesthesiologist in accordance with the ANSI/AAMI SP10-2002 regulation. Data analysis was performed based on the protocol criteria. In order to represent relationships between the test device and the reference method, Bland-Altman graphical... 

    Investigation on penetration of saffron components through lipid bilayer bound to spike protein of SARS-CoV-2 using steered molecular dynamics simulation

    , Article Heliyon ; Volume 6, Issue 12 , December , 2020 Kordzadeh, A ; Ramazani Saadatabadi, A ; Hadi, A ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    A coronavirus identified as COVID-19 is the reason for an infection outbreak which is started in December 2019. NO completely effective drugs and treatments are not recognized for this virus. Recently, saffron and its compounds were used to treat different viral diseases. Saffron extract and its major ingredients have shown antiviral effects. In this study, the steered molecular dynamics simulation was used for investigating the effect of four main components of saffron that include: crocin, crocetin, safranal, and picrocrocin as candidate for drug molecules, on COVID-19. The binding energies between drug molecules and spike protein and the main protease of the virus were evaluated. The... 

    An age index for vascular system based on photoplethysmogram pulse contour analysis

    , Article IFMBE Proceedings ; Volume 21 IFMBE, Issue 1 , 2008 , Pages 125-128 ; 16800737 (ISSN); 9783540691389 (ISBN) Chellappan, K ; Mohd Ali, M. A ; Zahedi, E ; Sharif University of Technology
    Springer Verlag  2008
    Abstract
    An approach based pulse on contour analysis is proposed for the development of an aging index for the vascular system. The approach is non-invasive, using photoplethysmography (PPG), which is in wide clinical use. A probe is applied to the subject's finger-tip to provide a measure of the pulse waveform. The measured waveforms are filtered, digitized and post-processed. Individual pulses are extracted and the best pulse was selected by using the best pulse selection algorithm. Pulse contour analysis is then performed with specially formulated PPG fitness equation. Results of measurements taken from 72 subjects are reported. The age range of the subjects was from 19 to 68 years, all of them... 

    Fatigue loaded intervertebral disc analysis for low back pain using nonlinear black-box model

    , Article IFMBE Proceedings ; Volume 39 , 2013 , Pages 513-517 ; 16800737 (ISSN) ; 9783642293047 (ISBN) Khan, M. F ; Malik, A. S ; Xia, L ; Nikkhoo, M ; Wang, J. L ; Parnianpour, M ; Humayun, J ; Sharif University of Technology
    2013
    Abstract
    This paper presents recent developments on effects of rest and fatigue loading on properties of healthy vertebra discs. A comparison of different approaches used in literature to study the properties of intervertebral disc is presented. The major achievements in this area so far are discussed in the context of their advantages and disadvantages. The past approaches are based on bio-mechanical models which mostly used statistical techniques for the analysis and estimation of fatigue loaded Intervertebral Disc (IVD). However, those modeling techniques were not flexible enough for analysis of customized tests. In this paper, we applied System Identification (SI) based NLARX modeling technique... 

    Numerical and 1-D modeling of pulmonary circulation along with lumped parameter modeling of the heart

    , Article 2013 20th Iranian Conference on Biomedical Engineering, ICBME 2013 ; December , 2013 , Pages 93-97 Salehi, S. S ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
    IEEE Computer Society  2013
    Abstract
    A one dimensional model of the pulmonary arterial network along with systemic circulation was introduced to quantify the human pulmonary artery hemodynamics. A lumped parameter model of the right ventricle was used as the inlet boundary condition. A time varying elastance related the volume and pressure of the right ventricle was imposed in the model. By using a four element Windkessel model, blood flow rate throughout the right ventricle was in hand. An asymmetric structured tree was chosen as the outlet boundary conditions. Simulation was based on solving one-dimensional equations of conservation of mass and momentum by using finite volume method. Blood flow rate, pressure and velocity... 

    Continuum model of actin-myosin flow

    , Article 2013 20th Iranian Conference on Biomedical Engineering, ICBME 2013 ; December , 2013 , Pages 98-102 Nikmaneshi, M. R ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
    IEEE Computer Society  2013
    Abstract
    The front part of a cell is divided to two regions called lamellum and lamellipodium (lamellipodial). This part plays an essential role for cell migration. Indeed, there are many protein filaments called actin in lamellum and lamellipodium, which induce the cell motion with polymerization in the leading edge of the cell. The actin filaments adhere to the extracellular matrix (ECM) by means of focal adhesions and they have contact by myosin motor proteins. The myosin motor proteins cause actin retrograde and anterograde flow exerted contractile stress on them. The focal adhesions exert frictional stress on the actin filaments. In this work, we developed a two-dimensional continuum model of... 

    3-D electrical model of a neuroprosthesis stimulator based on the concept of stimulus router system

    , Article 2013 20th Iranian Conference on Biomedical Engineering, ICBME 2013 ; 2013 , Pages 265-268 Ashiri, M ; Zahedi, E ; Sharif University of Technology
    IEEE Computer Society  2013
    Abstract
    Lost sensory or motor functions can be restored using electrical neural prostheses (NP), which include surface NPs, implanted or subcutaneous NPs and the more recent Stimulus Router System (SRS). The latter type of NP outperforms the other types in its selective excitation and least invasiveness. In each case, the achieved performance depends on a multitude of design factors among which the electrical excitation waveform shape, frequency, duration of pulses, configuration of electrodes, number of intervals, thermal conditions and electrode material. To investigate the effects of these parameters on the distribution of electric current inside biological tissues, numerical modeling can be... 

    Landmark and intensity based image registration using free form deformation

    , Article 2012 IEEE-EMBS Conference on Biomedical Engineering and Sciences, IECBES 2012 ; 2012 , Pages 768-771 ; 9781467316668 (ISBN) Ghaffari, A ; Khorsandi, R ; Fatemizadeh, E ; University Malaya; CBMTI University Malaya; Tourism Malaysia; Kumpulan ABEX Sdn Bhd; AMAN kampus ; Sharif University of Technology
    2012
    Abstract
    The registration of images is a fundamental task in numerous applications in medical image processing. In this paper, a novel registration technique is proposed which combines landmark and intensity based approaches. In this framework, the free form deformation (FFD) is used as transformation which is the key point of our algorithm. Landmarks with FFD transformation define the guidance surface which increases robustness of intensity based registration to bias field (bias noise). In fact, the performance of registration is improved by matching both landmark and intensity information. The experimental results show that the proposed method is more accurate than only intensity based method... 

    Modeling of photoplethysmography signal for quantitative analysis of endothelial cells during reactive hyperemia

    , Article 2012 19th Iranian Conference of Biomedical Engineering, ICBME 2012 ; 2012 , Pages 174-178 ; 9781467331302 (ISBN) Shiri, F ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
    2012
    Abstract
    In this study, at first the cardiovascular system is modeled based on the 1D method and then the simulation of the reactive hyperemia experiment has been applied on the model. In this simulation, by applying a cuff at the brachial artery, the flow downstream of the cuff is occluded. Then with releasing the cuff immediately, a large amount of shear stress, about 4 times the basal amount, is applied downstream of the cuff and consequently to the endothelial cells in a very short moment. Considering a reported experimental transfer function between shear stress and vasodilation, the increase of the artery diameter due to the sudden increase of the shear stress is obtained. Finally, the... 

    A review of commercially available non-invasive vascular screening technologies for clinical applications

    , Article 2012 IEEE-EMBS Conference on Biomedical Engineering and Sciences, IECBES 2012, 17 December 2012 through 19 December 2012 ; December , 2012 , Pages 568-573 ; 9781467316668 (ISBN) Sohani, V ; Zahedi, E ; Chellappan, K ; Mohd Ali, M. A ; Sharif University of Technology
    2012
    Abstract
    Cardiovascular diseases contribute to one third of the world's mortality and morbidity, therefore early cardiovascular disease diagnosis, treatment and monitoring has become an important market. Ideally, an early diagnosis device will need to be accurate, non-invasive, low cost and operator independent. Interestingly enough, there is a wide range of non-invasive devices available, but each with a different degree of accuracy and ease of use. In this paper, an attempt has been made to review commercially available technologies for non-invasive vascular screening. As stiffness index, reflection index, augmentation index, central aortic pressure are most commonly used to screen for vascular... 

    Simultaneous triple joint movement fuzzy control in FES-assisted rowing exercise

    , Article 2012 19th Iranian Conference of Biomedical Engineering, ICBME 2012, 20 December 2012 through 21 December 2012 ; December , 2012 , Pages 66-70 ; 9781467331302 (ISBN) Zarei, M ; Jahed, M ; Mehravar, M ; Sharif University of Technology
    2012
    Abstract
    Fuzzy Control of rowing exercise using Functional Electrical Stimulation (FES) concerns ankle, knee and hip joints. Muscular Modeling for each joint may contain two groups of muscles, namely extension and flexion. In the proposed method, joint controllers provide electrical stimulation pulses to the appropriate muscle group based on the trajectory error and according to a prescribed pattern designed for rowing exercise. Results indicate that the simulated Fuzzy control of desired angles closely match the experimental values for prescribed joints. Moreover, the robustness of the controller in presence of external disturbance is examined and the results show that the tracking of each joint... 

    A survey on talamocortical activity of ADHD patients based on mean-field bursting model

    , Article 10th IEEE International Workshop on Biomedical Engineering, BioEng 2011, Kos Island, 5 October 2011 through 7 October 2011 ; 2011 ; 9781457705526 (ISBN) Arasteh, A ; Janghorbani, A ; Vahdat, B. V ; University of Patras; University of Ioannina; National Technical University of Athens; University of Thessaly; Univ. Ioannina, Unit Med. Technol. Intelligent Inf. Syst ; Sharif University of Technology
    2011
    Abstract
    Modeling is one of assessing tools for better understanding of human body organs and study of diseases. One of the brain diseases is ADHD, which has been studied before, mostly by means of EEG signals. In this paper, the mean-field model, which is a model of neuron-population spiking, and the Power Spectrum of the resulting spikes have been studied by changing parameters of model. The results show that there is a meaningful relationship between firing activity of ADHD patients neuron population and the parameters of mean-field model and Power Spectrum of spikes. In addition, the effects of stimulant medications for ADHD patients on firing activity and power spectrum of firing activity of... 

    Controlling Atrial fibrillation using Cohen's model

    , Article 2011 18th Iranian Conference of Biomedical Engineering, ICBME 2011, 14 December 2011 through 16 December 2011 ; December , 2011 , Pages 60-63 ; 9781467310055 (ISBN) Aghajari, S ; Bahrami, F ; Sharif University of Technology
    2011
    Abstract
    Drug administration using infusion pumps can find application in treating patients with arrhythmias. These pumps can obviate the need to use drugs several times a day and automatically adapt the dosage to patient situation. Considering the importance of administration of right dosage, a perfect-controlled pump is needed to approach this goal. This paper focuses on controlling Atrial fibrillation (AF) arrhythmia. The abnormal heart rhythm that affects RR interval sequence and there have been some attempts to model these effects. One of these models is proposed by Cohen and colleges. Searching through the variables of this model, selecting the potential control variable (the one that its... 

    Computational investigation of sulphate diffusion into the dog disc

    , Article 2011 18th Iranian Conference of Biomedical Engineering, ICBME 2011, 14 December 2011 through 16 December 2011 ; December , 2011 , Pages 161-164 ; 9781467310055 (ISBN) Motaghinasab, S ; Shirazi Adl, A ; Urban, J ; Parnianpour, M ; Hoviattalab, M ; Sharif University of Technology
    2011
    Abstract
    We proposed a model to investigate the transient diffusion of drug (sulphate) into the intervertebral disc. Using finite element method, drug diffusion was simulated and the concentration of diffused drug in each region of disc including Nucleus pulpous (NP), Inner annulus fibroses (IA), and Outer annulus fibroses (OA) was measured. In addition, to investigate the role of CEP permeability on the amount of diffused drug, model was simulated with different cartilage endplate (CEP) permeability. Having obtained concentration distribution for different cases, it was clearly shown that the amount of diffused drug is affected by the endplate permeability and the more permeable CEP, the more... 

    ECG based human identification using wavelet distance measurement

    , Article Proceedings - 2011 4th International Conference on Biomedical Engineering and Informatics, BMEI 2011, 15 October 2011 through 17 October 2011 ; Volume 2 , October , 2011 , Pages 717-720 ; 9781424493524 (ISBN) Naraghi, M. E ; Shamsollahi, M. B ; Sharif University of Technology
    2011
    Abstract
    In this Paper a new approach is proposed for electrocardiogram (ECG) based human identification using wavelet distance measurement. The main advantage of this method is that it guarantees high accuracy even in abnormal cases. Furthermore, it possesses low sensitivity to noise. The algorithm was applied on 11 normal subjects and 10 abnormal subjects of MIT-BIH Database using single lead data, and a 100% human identification rate was on both normal and abnormal subjects. Adding artificial white noise to signals shows that the method is nearly accurate in SNR level above 5dB in normal subjects and 20dB in abnormal subjects