Search for: sensitivity-and-specificity
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    Adaptive sparse representation for MRI noise removal

    , Article Biomedical Engineering - Applications, Basis and Communications ; Volume 24, Issue 5 , October , 2012 , Pages 383-394 ; 10162372 (ISSN) Khalilzadeh, M. M ; Fatemizadeh, E ; Behnam, H ; Sharif University of Technology
    World Scientific  2012
    Sparse representation is a powerful tool for image processing, including noise removal. It is an effective method for Gaussian noise removal by taking advantage of a fixed and learned dictionary. In this study, the variable distribution of Rician noise is reduced in magnetic resonance (MR) images by sparse representation based on reconstruction error sets. Standard deviation of Gaussian noise is used to find these errors locally. The proposed method represents two formulas for local error calculation using standard deviation of noise. The acquired results from the real and simulated images are comparable, and in some cases, better than the best Rician noise removal method due to the... 

    Automatic segmentation, detection, and diagnosis of abdominal aortic aneurysm (AAA) using convolutional neural networks and hough circles algorithm

    , Article Cardiovascular Engineering and Technology ; Volume 10, Issue 3 , 2019 , Pages 490-499 ; 1869408X (ISSN) Mohammadi, S ; Mohammadi, M ; Dehlaghi, V ; Ahmadi, A ; Sharif University of Technology
    Springer New York LLC  2019
    Purpose: An abdominal aortic aneurysm (AAA) is known as a cardiovascular disease involving localized deformation (swelling or enlargement) of aorta occurring between the renal and iliac arteries. AAA would jeopardize patients’ lives due to its rupturing risk, so prompt recognition and diagnosis of this disorder is vital. Although computed tomography angiography (CTA) is the preferred imaging modality used by radiologist for diagnosing AAA, computed tomography (CT) images can be used too. In the recent decade, there has been several methods suggested by experts in order to find a precise automated way to diagnose AAA without human intervention base on CT and CTA images. Despite great... 

    Application of single-nucleotide polymorphisms in the diagnosis of autism spectrum disorders: a preliminary study with artificial neural networks

    , Article Journal of Molecular Neuroscience ; Volume 68, Issue 4 , 2019 , Pages 515-521 ; 08958696 (ISSN) Ghafouri Fard, S ; Taheri, M ; Omrani, M. D ; Daaee, A ; Mohammad Rahimi, H ; Kazazi, H ; Sharif University of Technology
    Springer New York LLC  2019
    Autism spectrum disorder (ASD) includes different neurodevelopmental disorders characterized by deficits in social communication, and restricted, repetitive patterns of behavior, interests or activities. Based on the importance of early diagnosis for effective therapeutic intervention, several strategies have been employed for detection of the disorder. The artificial neural network (ANN) as a type of machine learning method is a common strategy. In the current study, we extracted genomic data for 487 ASD patients and 455 healthy individuals. All individuals were genotyped in certain single-nucleotide polymorphisms within retinoic acid-related orphan receptor alpha (RORA), gamma-aminobutyric... 

    Abnormal expression of NF-κB-related transcripts in blood of patients with inflammatory peripheral nerve disorders

    , Article Metabolic Brain Disease ; Volume 36, Issue 8 , 2021 , Pages 2369-2376 ; 08857490 (ISSN) Azimi, T ; Ghafouri Fard, S ; Badrlou, E ; Omrani, D ; Nazer, N ; Sayad, A ; Taheri, M ; Sharif University of Technology
    Springer  2021
    The NF-κB family includes some transcription factors which have important functions in the regulation of immune responses, therefore participating in the pathophysiology of inflammatory conditions such as peripheral neuropathies. We have quantified expression of a number of NF-κB-related transcripts in patients with Guillain-Barré syndrome (GBS) or chronic inflammatory demyelinating polyneuropathy (CIDP) versus healthy subjects. These transcripts have been previously shown to be functionally related with this family of transcription factors. Expressions of ATG5, DICER-AS1, PACER, DILC, NKILA and ADINR have been increased in both CIDP and GBS patients compared with controls. However,... 

    Classification of asthma based on nonlinear analysis of breathing pattern

    , Article PLoS ONE ; Volume 11, Issue 1 , 2016 ; 19326203 (ISSN) Raoufy, M. R ; Ghafari, T ; Darooei, R ; Nazari, M ; Mahdaviani, S. A ; Eslaminejad, A. R ; Almasnia, M ; Gharibzadeh, S ; Mani, A. R ; Hajizadeh, S ; Sharif University of Technology
    Public Library of Science  2016
    Normal human breathing exhibits complex variability in both respiratory rhythm and volume. Analyzing such nonlinear fluctuations may provide clinically relevant information in patients with complex illnesses such as asthma. We compared the cycle-by-cycle fluctuations of inter-breath interval (IBI) and lung volume (LV) among healthy volunteers and patients with various types of asthma. Continuous respiratory datasets were collected from forty agematched men including 10 healthy volunteers, 10 patients with controlled atopic asthma, 10 patients with uncontrolled atopic asthma, and 10 patients with uncontrolled non-atopic asthma during 60 min spontaneous breathing. Complexity of breathing... 

    Images of finite sized spherical particles in confocal and conventional microscopes when illuminated with arbitrary polarization

    , Article Applied Optics ; Volume 47, Issue 3 , 2008 , Pages 453-458 ; 1559128X (ISSN) Alali, S ; Massoumian, F ; Sharif University of Technology
    OSA - The Optical Society  2008
    We investigate the form of the image of a finite sized spherical particle in confocal and conventional microscopes when the illuminating light has an arbitrary polarization. In particular, we take the cases of radial and azimuthal polarizations and use the Mie theory to find the scattered field from differently sized particles for these cases. We present numerical results for the changes in the detected intensity when subresolution and resolvable spherical particles are illuminated with particular wavelengths and polarizations. Further, we find the limiting size of a particle for which it can be considered a point scatterer for a particular wavelength. © 2008 Optical Society of America  

    Altered expression of STAT genes in periodontitis

    , Article Human Antibodies ; Volume 29, Issue 3 , 2021 , Pages 209-216 ; 10932607 (ISSN) Gholami, L ; Movafagh, A ; Badrlou, E ; Nazer, N ; Yari, M ; Sadeghi, G ; Mirzajani, S ; Shadnoush, M ; Sayad, A ; Ghafouri Fard, S ; Sharif University of Technology
    IOS Press BV  2021
    Signal Transducer and Activator of Transcription (STAT) pathway is functionally located downstream of Janus kinases proteins and can integrate signals from diverse pathways, thus regulating several aspects of immune responses. Although contribution of STAT proteins in the pathogenesis of several inflammatory conditions has been confirmed, their role in the development of periodontitis has been less appraised. Thus, we assessed levels of STAT transcripts in the periodontal tissues and circulation of affected individuals compared with the corresponding controls. Expression of STAT1 was remarkably lower in tissues samples of patients compared with control tissues (Ratio of mean expression (RME)... 

    Detection of fast ripples using Hidden Markov Model

    , Article 2014 21st Iranian Conference on Biomedical Engineering, ICBME 2014, 26 November 2014 through 28 November 2014 ; November , 2014 , Pages 348-352 ; 9781479974177 (ISBN) Nazarimehr, F ; Montazeri, N ; Shamsollahi, M. B ; Kachenoura, A ; Wendung, F ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2014
    Studies show that High frequency oscillations (HFOs) can be used as a reliable biomarker of epileptogenic zone, thus many algorithms have been proposed to detect HFOs. Among the wide variety of HFOs, fast ripples (FRs) are important transient oscillations occurring in the frequency band ranging from 250 Hz to 600 Hz. The automatic detection of FRs can be degenerated by the presence of some 'pulse-like' events (commonly, the component of interictal epileptic spikes) associated with an increase of the signal energy in the high frequency bands, exactly as in the case of real FRs. The goal of this study is to propose a new method for automatic detection of fast ripples by using Hidden Markov... 

    Manifold learning for ECG arrhythmia recognition

    , Article 2013 20th Iranian Conference on Biomedical Engineering, ICBME 2013 ; 2013 , Pages 126-131 Lashgari, E ; Jahed, M ; Khalaj, B ; Sharif University of Technology
    IEEE Computer Society  2013
    Heart is a complex system and we can find its function in electrocardiogram (ECG) signal. The records show high mortality rate of heart diseases. So it is essential to detect and recognize ECG arrhythmias. The problem with ECG analysis is the vast variations among morphologies of ECG signals. Premature Ventricular Contractions (PVC) is a common type of arrhythmia which may lead to critical situations and contains risk. This study, proposes a novel approach for detecting PVC and visualizing data with respect to ECG morphologies by using manifold learning. To this end, the Laplacian Eigenmaps - One of the reduction method and it is in the nonlinear category - is used to extract important... 

    Cuffless blood pressure estimation algorithms for continuous health-care monitoring

    , Article IEEE Transactions on Biomedical Engineering ; Volume 64, Issue 4 , 2017 , Pages 859-869 ; 00189294 (ISSN) Kachuee, M ; Kiani, M. M ; Mohammadzade, H ; Shabany, M ; Sharif University of Technology
    IEEE Computer Society  2017
    Goal: Continuous blood pressure (BP) monitoring can provide invaluable information about individuals' health conditions. However, BP is conventionally measured using inconvenient cuff-based instruments, which prevents continuous BP monitoring. This paper presents an efficient algorithm, based on the pulse arrival time (PAT), for the continuous and cuffless estimation of the systolic BP, diastolic blood pressure (DBP), and mean arterial pressure (MAP) values. Methods: The proposed framework estimates the BP values through processing vital signals and extracting two types of features, which are based on either physiological parameters or whole-based representation of vital signals. Finally,... 

    Over-Expression of immune-related lncrnas in inflammatory demyelinating polyradiculoneuropathies

    , Article Journal of Molecular Neuroscience ; Volume 71, Issue 5 , 2021 , Pages 991-998 ; 08958696 (ISSN) Sadeghpour, S ; Ghafouri-Fard, S ; Mazdeh, M ; Nicknafs, F ; Nazer, N ; Sayad, A ; Taheri, M ; Sharif University of Technology
    Humana Press Inc  2021
    Long non-coding RNAs (lncRNAs) have crucial roles in the pathogenesis of immune-related disorders. However, their role in the pathobiology of inflammatory demyelinating polyradiculoneuropathies remains unclear. In the current study, we measured peripheral expression of four lncRNAs, namely TUG1, FAS-AS1, NEAT1, and GAS5, in patients with acute/chronic inflammatory demyelinating polyradiculoneuropathies (AIDP/CIDP) compared with healthy subjects. Notably, all lncRNAs were over-expressed in patients compared with controls (P < 0.0001 for all lncRNAs). When assessing their expressions in AIDP and CIDP groups separately, TUG1 and NEAT1 were up-regulated in both patient groups compared with... 

    COVID-19 diagnosis using capsule network and fuzzy c -means and mayfly optimization algorithm

    , Article BioMed Research International ; Volume 2021 , 2021 ; 23146133 (ISSN) Farki, A ; Salekshahrezaee, Z ; Mohammadi Tofigh, A ; Ghanavati, R ; Arandian, B ; Chapnevis, A ; Sharif University of Technology
    Hindawi Limited  2021
    The COVID-19 epidemic is spreading day by day. Early diagnosis of this disease is essential to provide effective preventive and therapeutic measures. This process can be used by a computer-aided methodology to improve accuracy. In this study, a new and optimal method has been utilized for the diagnosis of COVID-19. Here, a method based on fuzzy C-ordered means (FCOM) along with an improved version of the enhanced capsule network (ECN) has been proposed for this purpose. The proposed ECN method is improved based on mayfly optimization (MFO) algorithm. The suggested technique is then implemented on the chest X-ray COVID-19 images from publicly available datasets. Simulation results are... 

    Automated detection of autism spectrum disorder using a convolutional neural network

    , Article Frontiers in Neuroscience ; Volume 13 , 2020 Sherkatghanad, Z ; Akhondzadeh, M ; Salari, S ; Zomorodi Moghadam, M ; Abdar, M ; Acharya, U. R ; Khosrowabadi, R ; Salari, V ; Sharif University of Technology
    Frontiers Media S.A  2020
    Background: Convolutional neural networks (CNN) have enabled significant progress in speech recognition, image classification, automotive software engineering, and neuroscience. This impressive progress is largely due to a combination of algorithmic breakthroughs, computation resource improvements, and access to a large amount of data. Method: In this paper, we focus on the automated detection of autism spectrum disorder (ASD) using CNN with a brain imaging dataset. We detected ASD patients using most common resting-state functional magnetic resonance imaging (fMRI) data from a multi-site dataset named the Autism Brain Imaging Exchange (ABIDE). The proposed approach was able to classify ASD... 

    Expression analysis of protein inhibitor of activated stat in inflammatory demyelinating polyradiculoneuropathy

    , Article Frontiers in Immunology ; Volume 12 , 2021 ; 16643224 (ISSN) Ghafouri Fard, S ; Hussen, B. M ; Nicknafs, F ; Nazer, N ; Sayad, A ; Taheri, M ; Sharif University of Technology
    Frontiers Media S.A  2021
    Protein inhibitors of activated STAT (PIAS) are involved in the regulation of the JAK/STAT signaling pathway and have interactions with NF-κB, p73 and p53. These proteins regulate immune responses; therefore dysregulation in their expression leads to several immune-mediated disorders. In the present study, we examined expression of PIAS1-4 in peripheral blood of patients with acute/chronic inflammatory demyelinating polyradiculoneuropathy (AIDP/CIDP) compared with healthy subjects. We demonstrated down-regulation of all PIAS genes in both AIDP and CIDP cases compared with controls. Similarly, comparisons in gender-based groups revealed down-regulation of these gene0s in patients of each... 

    Discrimination between different degrees of coronary artery disease using time-domain features of the finger photoplethysmogram in response to reactive hyperemia

    , Article Biomedical Signal Processing and Control ; Volume 18 , 2015 , Pages 282-292 ; 17468094 (ISSN) Hosseini, Z. S ; Zahedi, E ; Movahedian Attar, H ; Fakhrzadeh, H ; Parsafar, M. H ; Sharif University of Technology
    Elsevier Ltd  2015
    Atherosclerosis is a major cause of coronary artery disease leading to morbidity and mortality worldwide. Currently, coronary angiography is considered to be the most accurate technique to diagnose coronary artery disease (CAD). However, this technique is an invasive and expensive procedure with risks of serious complications. Since the symptoms of CAD are not noticed until advanced stages of the disease, early and effective diagnosis of CAD is considered a pertinent measure. In this paper, a non-invasive optical signal, the finger photoplethysmogram (PPG) obtained before and after reactive hyperemia is investigated to discriminate between subjects with different CAD conditions. To this end,... 

    An expert system for selecting wart treatment method

    , Article Computers in Biology and Medicine ; Volume 81 , 2017 , Pages 167-175 ; 00104825 (ISSN) Khozeimeh, F ; Alizadehsani, R ; Roshanzamir, M ; Khosravi, A ; Layegh, P ; Nahavandi, S ; Sharif University of Technology
    Elsevier Ltd  2017
    As benign tumors, warts are made through the mediation of Human Papillomavirus (HPV) and may grow on all parts of body, especially hands and feet. There are several treatment methods for this illness. However, none of them can heal all patients. Consequently, physicians are looking for more effective and customized treatments for each patient. They are endeavoring to discover which treatments have better impacts on a particular patient. The aim of this study is to identify the appropriate treatment for two common types of warts (plantar and common) and to predict the responses of two of the best methods (immunotherapy and cryotherapy) to the treatment. As an original work, the study was... 

    Multi-class segmentation of skin lesions via joint dictionary learning

    , Article Biomedical Signal Processing and Control ; Volume 68 , 2021 ; 17468094 (ISSN) Moradi, N ; Mahdavi Amiri, N ; Sharif University of Technology
    Elsevier Ltd  2021
    Melanoma is the deadliest type of human skin cancer. However, it is curable if diagnosed in an early stage. Recently, computer aided diagnosis (CAD) systems have drawn much interests. Segmentation is a crucial step of a CAD system. There are different types of skin lesions having high similarities in terms of color, shape, size and appearance. Most available works focus on a binary segmentation. Due to the huge variety of skin lesions and high similarities between different types of lesions, multi-class segmentation is still a challenging task. Here, we propose a method based on joint dictionary learning for multi-class segmentation of dermoscopic images. The key idea is based on combining... 

    Comparison of near-infrared (NIR) and mid-infrared (MIR) spectroscopy based on chemometrics for saffron authentication and adulteration detection

    , Article Food Chemistry ; Volume 344 , 2021 ; 03088146 (ISSN) Amirvaresi, A ; Nikounezhad, N ; Amirahmadi, M ; Daraei, B ; Parastar, H ; Sharif University of Technology
    Elsevier Ltd  2021
    In this work, the potential of near-infrared (NIR) and mid-infrared (MIR) spectroscopy along with chemometrics was investigated for authentication and adulteration detection of Iranian saffron samples. First, authentication of one-hundred saffron samples was examined by principal component analysis (PCA). The results showed the NIR spectroscopy can better predict the origin of samples than the MIR. Next, partial least squares-discriminant analysis (PLS-DA) was developed to detect four common plant-derived adulterants (i.e., saffron style, calendula, safflower, and rubia). In all cases, PLS-DA classification figures of merit in terms of sensitivity, specificity, error rate and accuracy were... 

    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) Arabasadi, Z ; 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... 

    Design and fabrication of an electrochemical aptasensor using Au nanoparticles/carbon nanoparticles/cellulose nanofibers nanocomposite for rapid and sensitive detection of Staphylococcus aureus

    , Article Bioelectrochemistry ; Volume 123 , 2018 , Pages 70-76 ; 15675394 (ISSN) Ranjbar, S ; Shahrokhian, S ; Sharif University of Technology
    Elsevier B.V  2018
    Since that pathogenic bacteria are major threats to human health, this paper describes the fabrication of an effective and durable sensing platform based on gold nanoparticles/carbon nanoparticles/cellulose nanofibers nanocomposite (AuNPs/CNPs/CNFs) at the surface of glassy carbon electrode for sensitive and selective detection of Staphylococcus aureus (S. aureus). The AuNPs/CNPs/CNFs nanocomposite with the high surface area, excellent conductivity, and good biocompatibility was used for self-assembled of the thiolated specific S. aureus aptamer as a sensing element. The surface morphology of AuNPs/CNPs/CNFs nanocomposite was characterized with field emission scanning electron microscopy...