Sample Entropy Analysis of Noisy Atrial Electrograms during Atrial Fibrillation.
Authors: Cirugeda-Roldán EM, Molina Picó A, Novák D, Cuesta-Frau D, Kremen V Abstract Most cardiac arrhythmias can be classified as atrial flutter, focal atrial tachycardia, or atrial fibrillation. They have been usually treated using drugs, but catheter ablation has proven more effective. This is an invasive method devised to destroy the heart tissue that disturbs correct heart rhythm. In order to accurately localise the focus of this disturbance, the acquisition and processing of atrial electrograms form the usual mapping technique. They can be single potentials, double potentials, or complex...
Source: Computational and Mathematical Methods in Medicine - July 18, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Wall Shear Stress Estimation of Thoracic Aortic Aneurysm Using Computational Fluid Dynamics.
Authors: Febina J, Sikkandar MY, Sudharsan NM Abstract An attempt has been made to evaluate the effects of wall shear stress (WSS) on thoracic aortic aneurysm (TAA) using Computational Fluid Dynamics (CFD). Aneurysm is an excessive localized swelling of the arterial wall due to many physiological factors and it may rupture causing shock or sudden death. The existing imaging modalities such as MRI and CT assist in the visualization of anomalies in internal organs. However, the expected dynamic behaviour of arterial bulge under stressed condition can only be effectively evaluated through mathematical modelling. In th...
Source: Computational and Mathematical Methods in Medicine - July 18, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Information-Based Medicine in Glioma Patients: A Clinical Perspective.
Authors: Senders JT, Harary M, Stopa BM, Staples P, Broekman MLD, Smith TR, Gormley WB, Arnaout O Abstract Glioma constitutes the most common type of primary brain tumor with a dismal survival, often measured in terms of months or years. The thin line between treatment effectiveness and patient harm underpins the importance of tailoring clinical management to the individual patient. Randomized trials have laid the foundation for many neuro-oncological guidelines. Despite this, their findings focus on group-level estimates. Given our current tools, we are limited in our ability to guide patients on what therapy is b...
Source: Computational and Mathematical Methods in Medicine - July 18, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Automatic Optic Disc Detection in Color Retinal Images by Local Feature Spectrum Analysis.
Authors: Zhou W, Wu H, Wu C, Yu X, Yi Y Abstract The optic disc is a key anatomical structure in retinal images. The ability to detect optic discs in retinal images plays an important role in automated screening systems. Inspired by the fact that humans can find optic discs in retinal images by observing some local features, we propose a local feature spectrum analysis (LFSA) that eliminates the influence caused by the variable spatial positions of local features. In LFSA, a dictionary of local features is used to reconstruct new optic disc candidate images, and the utilization frequencies of every atom in the dict...
Source: Computational and Mathematical Methods in Medicine - July 18, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Structure Optimization for Large Gene Networks Based on Greedy Strategy.
Authors: Gómez-Vela F, Rodriguez-Baena DS, Vázquez-Noguera JL Abstract In the last few years, gene networks have become one of most important tools to model biological processes. Among other utilities, these networks visually show biological relationships between genes. However, due to the large amount of the currently generated genetic data, their size has grown to the point of being unmanageable. To solve this problem, it is possible to use computational approaches, such as heuristics-based methods, to analyze and optimize gene network's structure by pruning irrelevant relationships. In this paper w...
Source: Computational and Mathematical Methods in Medicine - July 18, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Mobile Personal Health Monitoring for Automated Classification of Electrocardiogram Signals in Elderly.
Authors: Mena LJ, Félix VG, Ochoa A, Ostos R, González E, Aspuru J, Velarde P, Maestre GE Abstract Mobile electrocardiogram (ECG) monitoring is an emerging area that has received increasing attention in recent years, but still real-life validation for elderly residing in low and middle-income countries is scarce. We developed a wearable ECG monitor that is integrated with a self-designed wireless sensor for ECG signal acquisition. It is used with a native purposely designed smartphone application, based on machine learning techniques, for automated classification of captured ECG beats from aged people...
Source: Computational and Mathematical Methods in Medicine - July 15, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Medical Image Fusion Based on Sparse Representation and PCNN in NSCT Domain.
Authors: Xia J, Chen Y, Chen A, Chen Y Abstract The clinical assistant diagnosis has a high requirement for the visual effect of medical images. However, the low frequency subband coefficients obtained by the NSCT decomposition are not sparse, which is not conducive to maintaining the details of the source image. To solve these problems, a medical image fusion algorithm combined with sparse representation and pulse coupling neural network is proposed. First, the source image is decomposed into low and high frequency subband coefficients by NSCT transform. Secondly, the K singular value decomposition (K-SVD) method ...
Source: Computational and Mathematical Methods in Medicine - July 12, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Understanding Dynamic Status Change of Hospital Stay and Cost Accumulation via Combining Continuous and Finitely Jumped Processes.
Authors: Zheng Y, Zhao X, Zhang X Abstract The Coxian phase-type models and the joint models of longitudinal and event time have been extensively used in the studies of medical outcome data. Coxian phase-type models have the finite-jump property while the joint models usually assume a continuous variation. The gap between continuity and discreteness makes the two models rarely used together. In this paper, a partition-based approach is proposed to jointly model the charge accumulation process and the time to discharge. The key construction of our new approach is a set of partition cells with their boundaries determ...
Source: Computational and Mathematical Methods in Medicine - July 11, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Common Interferences Removal from Dense Multichannel EEG Using Independent Component Decomposition.
Authors: Li W, Shen Y, Zhang J, Huang X, Chen Y, Ge Y Abstract To improve the spatial resolution, dense multichannel electroencephalogram with more than 32 leads has gained more and more applications. However, strong common interference will not only conceal the weak components generated from the specific isolated neural source, but also lead to severe spurious correlation between different brain regions, which results in great distortion on brain connectivity or brain network analysis. Starting from the fast independent component analysis algorithm, we first derive the mixing matrix of independent source component...
Source: Computational and Mathematical Methods in Medicine - July 8, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Method for Calculating the Bending Angle of Puncture Needle in Preoperative Planning for Transjugular Intrahepatic Portal Systemic Shunt (TIPS).
Authors: Zhu X, Ran Z, Li W, Wang W, Zhu K, Huang W, Gao X Abstract Transjugular Intrahepatic Portal Systemic Shunt is a comprehensive interventional therapy for portal hypertension. During this intervention, puncturing from hepatic vein into portal vein is a difficult step. Selecting puncture needle with a proper bending angle is vital to accurate puncture. Thus, this prospective study provides a method to calculate the angle of the puncture needle using preinterventional contrast-enhanced CT imaging. According to the geometrical characteristics of puncture needle, Bezier curve equation was adopted to describe its...
Source: Computational and Mathematical Methods in Medicine - July 8, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

The Scatter Search Based Algorithm for Beam Angle Optimization in Intensity-Modulated Radiation Therapy.
This article introduces a new framework for beam angle optimization (BAO) in intensity-modulated radiation therapy (IMRT) using the Scatter Search Based Algorithm. The potential benefits of plans employing the coplanar optimized beam sets are also examined. In the proposed beam angle selection algorithm, the problem is solved in two steps. Initially, the gantry angles are selected using the Scatter Search Based Algorithm, which is a global optimization method. Then, for each beam configuration, the intensity profile is calculated by the conjugate gradient method to score each beam angle set chosen. A simulated phantom case...
Source: Computational and Mathematical Methods in Medicine - July 5, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

The Modelling of Hand, Foot, and Mouth Disease in Contaminated Environments in Bangkok, Thailand.
In this study, a new mathematical model is proposed to investigate the effect of indirect transmission from contaminated environments and the impact of asymptomatic individuals. By fitting our model to reported data on hospitalized individuals of HFMD endemic in Bangkok, Thailand, 2016, the basic reproduction number was estimated as 1.441, which suggests that the disease will remain under current conditions. Numerical simulations show that the direct transmission from asymptomatic individuals and indirect transmission via free-living viruses are important factors which contribute to new HFMD infections. Sensitivity analysi...
Source: Computational and Mathematical Methods in Medicine - July 5, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Modelling Optimal Control of In-Host HIV Dynamics Using Different Control Strategies.
Authors: Ngina P, Mbogo RW, Luboobi LS Abstract HIV is one of the major causes of deaths, especially in Sub-Saharan Africa. In this paper, an in vivo deterministic model of differential equations is presented and analyzed for HIV dynamics. Optimal control theory is applied to investigate the key roles played by the various HIV treatment strategies. In particular, we establish the optimal strategies for controlling the infection using three treatment regimes as the system control variables. We have applied Pontryagin's Maximum Principle in characterizing the optimality control, which then has been solved numerically...
Source: Computational and Mathematical Methods in Medicine - July 5, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Computational Techniques for Eye Movements Analysis towards Supporting Early Diagnosis of Alzheimer's Disease: A Review.
We describe the progress in technology that can enhance the analysis of eye movements everywhere while subjects perform their daily activities and give future research directions to develop tools to support early AD diagnosis through analysis of eye movements. PMID: 29887912 [PubMed - in process] (Source: Computational and Mathematical Methods in Medicine)
Source: Computational and Mathematical Methods in Medicine - June 12, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

An Improved FastICA Method for Fetal ECG Extraction.
Conclusions: The proposed improved FastICA algorithm based on the overrelaxation factor, while maintaining the rate of convergence, relaxes the requirement of initial weight vector, avoids the unbalanced convergence, reduces the number of iterations, and improves the convergence performance. PMID: 29887913 [PubMed - in process] (Source: Computational and Mathematical Methods in Medicine)
Source: Computational and Mathematical Methods in Medicine - June 12, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

A New Approach towards Minimizing the Risk of Misdosing Warfarin Initiation Doses.
Authors: Sharabiani A, Nutescu EA, Galanter WL, Darabi H Abstract It is a challenge to be able to prescribe the optimal initial dose of warfarin. There have been many studies focused on an efficient strategy to determine the optimal initial dose. Numerous clinical, genetic, and environmental factors affect the warfarin dose response. In practice, it is common that the initial warfarin dose is substantially different from the stable maintenance dose, which may increase the risk of bleeding or thrombosis prior to achieving the stable maintenance dose. In order to minimize the risk of misdosing, despite popular warfar...
Source: Computational and Mathematical Methods in Medicine - June 5, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Pulmonary Nodule Recognition Based on Multiple Kernel Learning Support Vector Machine-PSO.
Authors: Li Y, Zhu Z, Hou A, Zhao Q, Liu L, Zhang L Abstract Pulmonary nodule recognition is the core module of lung CAD. The Support Vector Machine (SVM) algorithm has been widely used in pulmonary nodule recognition, and the algorithm of Multiple Kernel Learning Support Vector Machine (MKL-SVM) has achieved good results therein. Based on grid search, however, the MKL-SVM algorithm needs long optimization time in course of parameter optimization; also its identification accuracy depends on the fineness of grid. In the paper, swarm intelligence is introduced and the Particle Swarm Optimization (PSO) is combined wit...
Source: Computational and Mathematical Methods in Medicine - June 2, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Does the Temporal Asymmetry of Short-Term Heart Rate Variability Change during Regular Walking? A Pilot Study of Healthy Young Subjects.
This study was designed to examine whether altered autonomic balance during exercise can lead to HRA changes. Sixteen healthy college students were enrolled, and each student undertook two 5-min ECG measurements: one in a resting seated position and another while walking on a treadmill at a regular speed of 5 km/h. The two measurements were conducted in a randomized order, and a 30-min rest was required between them. RR interval time series were extracted from the 5-min ECG data, and HRA (short-term) was estimated using four established metrics, that is, Porta's index (PI), Guzik's index (GI), slope index (SI), and ...
Source: Computational and Mathematical Methods in Medicine - June 2, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Single-Frequency Ultrasound-Based Respiration Rate Estimation with Smartphones.
Authors: Ge L, Zhang J, Wei J Abstract Respiration monitoring is helpful in disease prevention and diagnosis. Traditional respiration monitoring requires users to wear devices on their bodies, which is inconvenient for them. In this paper, we aim to design a noncontact respiration rate detection system utilizing off-the-shelf smartphones. We utilize the single-frequency ultrasound as the media to detect the respiration activity. By analyzing the ultrasound signals received by the built-in microphone sensor in a smartphone, our system can derive the respiration rate of the user. The advantage of our method is that t...
Source: Computational and Mathematical Methods in Medicine - June 2, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

A Novel Model for Predicting Associations between Diseases and LncRNA-miRNA Pairs Based on a Newly Constructed Bipartite Network.
Authors: Zhou S, Xuan Z, Wang L, Ping P, Pei T Abstract Motivation: Increasing studies have demonstrated that many human complex diseases are associated with not only microRNAs, but also long-noncoding RNAs (lncRNAs). LncRNAs and microRNA play significant roles in various biological processes. Therefore, developing effective computational models for predicting novel associations between diseases and lncRNA-miRNA pairs (LMPairs) will be beneficial to not only the understanding of disease mechanisms at lncRNA-miRNA level and the detection of disease biomarkers for disease diagnosis, treatment, prognosis, and preventi...
Source: Computational and Mathematical Methods in Medicine - June 2, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Stochastic Periodic Solution of a Susceptible-Infective Epidemic Model in a Polluted Environment under Environmental Fluctuation.
Authors: Zhao Y, Li J, Ma X Abstract It is well known that the pollution and environmental fluctuations may seriously affect the outbreak of infectious diseases (e.g., measles). Therefore, understanding the association between the periodic outbreak of an infectious disease and noise and pollution still needs further development. Here we consider a stochastic susceptible-infective (SI) epidemic model in a polluted environment, which incorporates both environmental fluctuations as well as pollution. First, the existence of the global positive solution is discussed. Thereafter, the sufficient conditions for the nontri...
Source: Computational and Mathematical Methods in Medicine - June 2, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Modelling of the Current Density Distributions during Cortical Electric Stimulation for Neuropathic Pain Treatment.
This study aims to evaluate, by computational techniques, the current density distributions induced in the brain by a realistic electrode array for cortical stimulation. The simulation outcomes, summarized by specific metrics quantifying the efficacy of the stimulation (i.e., the effective volume and the effective depth of penetration) over two cortical targets, were evaluated by varying the interelectrode distance, the stimulus characteristics (amplitude and frequency), and the anatomical human model. The results suggest that all these parameters somehow affect the current density distributions and have to be therefore ta...
Source: Computational and Mathematical Methods in Medicine - June 1, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Kernel Principal Component Analysis of Coil Compression in Parallel Imaging.
Authors: Chang Y, Wang H Abstract A phased array with many coil elements has been widely used in parallel MRI for imaging acceleration. On the other hand, it results in increased memory usage and large computational costs for reconstructing the missing data from such a large number of channels. A number of techniques have been developed to linearly combine physical channels to produce fewer compressed virtual channels for reconstruction. A new channel compression technique via kernel principal component analysis (KPCA) is proposed. The proposed KPCA method uses a nonlinear combination of all physical channels to pr...
Source: Computational and Mathematical Methods in Medicine - June 1, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Online Appointment Scheduling for a Nuclear Medicine Department in a Chinese Hospital.
Authors: Xiao Q, Luo L, Zhao SZ, Ran XB, Feng YB Abstract Nuclear medicine, a subspecialty of radiology, plays an important role in proper diagnosis and timely treatment. Multiple resources, especially short-lived radiopharmaceuticals involved in the process of nuclear medical examination, constitute a unique problem in appointment scheduling. Aiming at achieving scientific and reasonable appointment scheduling in the West China Hospital (WCH), a typical class A tertiary hospital in China, we developed an online appointment scheduling algorithm based on an offline nonlinear integer programming model which considers...
Source: Computational and Mathematical Methods in Medicine - June 1, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Simulation Model for Dynamics of Dengue with Innate and Humoral Immune Responses.
This study provides a qualitative understanding of the biological factors that can explain the viral kinetics during a dengue infection. PMID: 29849749 [PubMed - in process] (Source: Computational and Mathematical Methods in Medicine)
Source: Computational and Mathematical Methods in Medicine - June 1, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Lung Cancer Mortality in Tuscany from 1971 to 2010 and Its Connections with Silicosis: A Space-Cohort Analysis Based on Shared Models.
Authors: Dreassi E Abstract Lung cancer mortality in Tuscany (Italy) for males, from 1971 and 2010, is investigated. A hierarchical Bayesian model for space-time disease mapping is introduced. Such a model belongs to the class of shared random effect models and exploits the birth-cohort as the relevant time dimension. It allows for highlighting common and specific patterns of risk for each birth-cohort. The results show that different birth-cohorts exhibit quite different spatial patterns, even if the socioeconomic status is taken into account. In fact, there were different occupational exposures before and after t...
Source: Computational and Mathematical Methods in Medicine - May 31, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

A Biologically Inspired Approach to Frequency Domain Feature Extraction for EEG Classification.
This study contributes to the development of single-channel BCI, as well as finding the best task pair for user defined applications. PMID: 29796060 [PubMed - in process] (Source: Computational and Mathematical Methods in Medicine)
Source: Computational and Mathematical Methods in Medicine - May 31, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Mathematical Modelling of Bacterial Meningitis Transmission Dynamics with Control Measures.
Authors: Asamoah JKK, Nyabadza F, Seidu B, Chand M, Dutta H Abstract Vaccination and treatment are the most effective ways of controlling the transmission of most infectious diseases. While vaccination helps susceptible individuals to build either a long-term immunity or short-term immunity, treatment reduces the number of disease-induced deaths and the number of infectious individuals in a community/nation. In this paper, a nonlinear deterministic model with time-dependent controls has been proposed to describe the dynamics of bacterial meningitis in a population. The model is shown to exhibit a unique globally as...
Source: Computational and Mathematical Methods in Medicine - May 22, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

WHODAS 2.0 as a Measure of Severity of Illness: Results of a FLDA Analysis.
In this study, we explore if WHODAS 2.0 can be used for identifying severity of illness measured by CGI using the Fisher Linear Discriminant Analysis (FLDA) and for identifying which individual items of WHODAS 2.0 best predict CGI scores given by clinicians. One hundred and twenty-two patients were assessed with WHODAS 2.0 and CGI during three months in outpatient mental health facilities of four hospitals of Madrid, Spain. Compared with the traditional correction of WHODAS 2.0, FLDA improves accuracy in near 15%, and so, with FLDA WHODAS 2.0 classifying correctly 59.0% of the patients. Furthermore, FLDA identifies item 6....
Source: Computational and Mathematical Methods in Medicine - May 19, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Fast and Accurate Genome-Wide Association Test of Multiple Quantitative Traits.
Authors: Wu B, Pankow JS Abstract Multiple correlated traits are often collected in genetic studies. By jointly analyzing multiple traits, we can increase power by aggregating multiple weak effects and reveal additional insights into the genetic architecture of complex human diseases. In this article, we propose a multivariate linear regression-based method to test the joint association of multiple quantitative traits. It is flexible to accommodate any covariates, has very accurate control of type I errors, and offers very competitive performance. We also discuss fast and accurate significance p value computation e...
Source: Computational and Mathematical Methods in Medicine - May 12, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Transfer Kernel Common Spatial Patterns for Motor Imagery Brain-Computer Interface Classification.
Authors: Dai M, Zheng D, Liu S, Zhang P Abstract Motor-imagery-based brain-computer interfaces (BCIs) commonly use the common spatial pattern (CSP) as preprocessing step before classification. The CSP method is a supervised algorithm. Therefore a lot of time-consuming training data is needed to build the model. To address this issue, one promising approach is transfer learning, which generalizes a learning model can extract discriminative information from other subjects for target classification task. To this end, we propose a transfer kernel CSP (TKCSP) approach to learn a domain-invariant kernel by directly match...
Source: Computational and Mathematical Methods in Medicine - May 12, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Automated Segmentation Methods of Drusen to Diagnose Age-Related Macular Degeneration Screening in Retinal Images.
Authors: Kim YJ, Kim KG Abstract Existing drusen measurement is difficult to use in clinic because it requires a lot of time and effort for visual inspection. In order to resolve this problem, we propose an automatic drusen detection method to help clinical diagnosis of age-related macular degeneration. First, we changed the fundus image to a green channel and extracted the ROI of the macular area based on the optic disk. Next, we detected the candidate group using the difference image of the median filter within the ROI. We also segmented vessels and removed them from the image. Finally, we detected the drusen thr...
Source: Computational and Mathematical Methods in Medicine - May 5, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Calculating the Mean Amplitude of Glycemic Excursions from Continuous Glucose Data Using an Open-Code Programmable Algorithm Based on the Integer Nonlinear Method.
Authors: Yu X, Lin L, Shen J, Chen Z, Jian J, Li B, Xin SX Abstract The mean amplitude of glycemic excursions (MAGE) is an essential index for glycemic variability assessment, which is treated as a key reference for blood glucose controlling at clinic. However, the traditional "ruler and pencil" manual method for the calculation of MAGE is time-consuming and prone to error due to the huge data size, making the development of robust computer-aided program an urgent requirement. Although several software products are available instead of manual calculation, poor agreement among them is reported. Therefore, ...
Source: Computational and Mathematical Methods in Medicine - May 2, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Feasibility of an AI-Based Measure of the Hand Motions of Expert and Novice Surgeons.
In conclusion, our artificial intelligence system distinguished between expert and novice surgeons among surgeons with unknown skill levels. PMID: 29686724 [PubMed - in process] (Source: Computational and Mathematical Methods in Medicine)
Source: Computational and Mathematical Methods in Medicine - April 26, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Multiclass Classification of Cardiac Arrhythmia Using Improved Feature Selection and SVM Invariants.
This study is conducted to classify patients into one of the sixteen subclasses, among which one class represents absence of disease and the other fifteen classes represent electrocardiogram records of various subtypes of arrhythmias. The research is carried out on the dataset taken from the University of California at Irvine Machine Learning Data Repository. The dataset contains a large volume of feature dimensions which are reduced using wrapper based feature selection technique. For multiclass classification, support vector machine (SVM) based approaches including one-against-one (OAO), one-against-all (OAA), and error-...
Source: Computational and Mathematical Methods in Medicine - April 26, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Bayesian Correction for Misclassification in Multilevel Count Data Models.
Authors: Nelson T, Song JJ, Chin YM, Stamey JD Abstract Covariate misclassification is well known to yield biased estimates in single level regression models. The impact on hierarchical count models has been less studied. A fully Bayesian approach to modeling both the misclassified covariate and the hierarchical response is proposed. Models with a single diagnostic test and with multiple diagnostic tests are considered. Simulation studies show the ability of the proposed model to appropriately account for the misclassification by reducing bias and improving performance of interval estimators. A real data example fu...
Source: Computational and Mathematical Methods in Medicine - April 25, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Direct-Current Electric Field Distribution in the Brain for Tumor Treating Field Applications: A Simulation Study.
Authors: Sun YS Abstract Tumor Treating Fields (TTFields) in combination with chemotherapy and/or radiotherapy have been clinically reported to provide prolonged overall survival in glioblastoma patients. Alternating electric fields with frequencies of 100~300 kHz and magnitudes of 1~3 V/cm are shown to suppress the growth of cancer cells via interactions with polar molecules within dividing cells. Since it is difficult to directly measure the electric fields inside the brain, simulation models of the human head provide a useful tool for predicting the electric field distribution. In the present study...
Source: Computational and Mathematical Methods in Medicine - April 25, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Computer-Aided Diagnosis of Acute Lymphoblastic Leukaemia.
Authors: Shafique S, Tehsin S Abstract Leukaemia is a form of blood cancer which affects the white blood cells and damages the bone marrow. Usually complete blood count (CBC) and bone marrow aspiration are used to diagnose the acute lymphoblastic leukaemia. It can be a fatal disease if not diagnosed at the earlier stage. In practice, manual microscopic evaluation of stained sample slide is used for diagnosis of leukaemia. But manual diagnostic methods are time-consuming, less accurate, and prone to errors due to various human factors like stress, fatigue, and so forth. Therefore, different automated systems have be...
Source: Computational and Mathematical Methods in Medicine - April 25, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Simultaneous Segmentation of Leukocyte and Erythrocyte in Microscopic Images Using a Marker-Controlled Watershed Algorithm.
Authors: Miao H, Xiao C Abstract The density or quantity of leukocytes and erythrocytes in a unit volume of blood, which can be automatically measured through a computer-based microscopic image analysis system, is frequently considered an indicator of diseases. The segmentation of blood cells, as a basis of quantitative statistics, plays an important role in the system. However, many conventional methods must firstly distinguish blood cells into two types (i.e., leukocyte and erythrocyte) and segment them in independent procedures. In this paper, we present a marker-controlled watershed algorithm for simultaneously...
Source: Computational and Mathematical Methods in Medicine - April 25, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Global Dynamics of an Avian Influenza A(H7N9) Epidemic Model with Latent Period and Nonlinear Recovery Rate.
Authors: Mu R, Yang Y Abstract An SEIR type of compartmental model with nonlinear incidence and recovery rates was formulated to study the combined impacts of psychological effect and available resources of public health system especially the number of hospital beds on the transmission and control of A(H7N9) virus. Global stability of the disease-free and endemic equilibria is determined by the basic reproduction number as a threshold parameter and is obtained by constructing Lyapunov function and second additive compound matrix. The results obtained reveal that psychological effect and available resources do not c...
Source: Computational and Mathematical Methods in Medicine - April 25, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Numerical Simulations of the Motion and Deformation of Three RBCs during Poiseuille Flow through a Constricted Vessel Using IB-LBM.
The objective was to determine the effects of the degree of constriction and the Reynolds (Re) number of the flow on the physical characteristics of the RBCs. It was found that, with decreasing constriction ratio, the RBCs experienced greater forced deformation as they squeezed through the constriction area compared to at other parts of the microchannel. It was also observed that a longer time was required for the RBCs to squeeze through a narrower constriction. The RBCs subsequently regained a stable shape and gradually migrated toward the centerline of the flow beyond the constriction area. However, a sick RBC was observ...
Source: Computational and Mathematical Methods in Medicine - April 25, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

An Adaptive Calibration Framework for mVEP-Based Brain-Computer Interface.
Authors: Ma T, Li F, Li P, Yao D, Zhang Y, Xu P Abstract Electroencephalogram signals and the states of subjects are nonstationary. To track changing states effectively, an adaptive calibration framework is proposed for the brain-computer interface (BCI) with the motion-onset visual evoked potential (mVEP) as the control signal. The core of this framework is to update the training set adaptively for classifier training. The updating procedure consists of two operations, that is, adding new samples to the training set and removing old samples from the training set. In the proposed framework, a support vector machine...
Source: Computational and Mathematical Methods in Medicine - April 25, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Analysis and Numerical Simulations of a Stochastic SEIQR Epidemic System with Quarantine-Adjusted Incidence and Imperfect Vaccination.
Authors: Li F, Meng X, Wang X Abstract This paper considers a high-dimensional stochastic SEIQR (susceptible-exposed-infected-quarantined-recovered) epidemic model with quarantine-adjusted incidence and the imperfect vaccination. The main aim of this study is to investigate stochastic effects on the SEIQR epidemic model and obtain its thresholds. We first obtain the sufficient condition for extinction of the disease of the stochastic system. Then, by using the theory of Hasminskii and the Lyapunov analysis methods, we show there is a unique stationary distribution of the stochastic system and it has an ergodic prop...
Source: Computational and Mathematical Methods in Medicine - April 22, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Corrigendum to "Association of Stressful Life Events with Psychological Problems: A Large-Scale Community-Based Study Using Grouped Outcomes Latent Factor Regression with Latent Predictors".
Corrigendum to "Association of Stressful Life Events with Psychological Problems: A Large-Scale Community-Based Study Using Grouped Outcomes Latent Factor Regression with Latent Predictors". Comput Math Methods Med. 2018;2018:8020962 Authors: Hassanzadeh A, Heidari Z, Feizi A, Hassanzadeh Keshteli A, Roohafza H, Afshar H, Adibi P Abstract [This corrects the article DOI: 10.1155/2017/3457103.]. PMID: 29676393 [PubMed - in process] (Source: Computational and Mathematical Methods in Medicine)
Source: Computational and Mathematical Methods in Medicine - April 22, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Novel Model for Cascading Failure Based on Degree Strength and Its Application in Directed Gene Logic Networks.
Authors: Zhang Y, Zhao M, Su J, Lu X, Lv K Abstract A novel model for cascading failures in a directed logic network based on the degree strength at a node was proposed. The definitions of in-degree and out-degree strength of a node were initially reconsidered, and the load at a nonisolated node was proposed as the ratio of in-degree strength to out-degree strength of the node. The cascading failure model based on degree strength was applied to the logic network for three types of cancer including adenocarcinoma of lung, prostate cancer, and colon cancer based on their gene expression profiles. In order to highligh...
Source: Computational and Mathematical Methods in Medicine - April 21, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Feature Genes Selection Using Supervised Locally Linear Embedding and Correlation Coefficient for Microarray Classification.
Authors: Xu J, Mu H, Wang Y, Huang F Abstract The selection of feature genes with high recognition ability from the gene expression profiles has gained great significance in biology. However, most of the existing methods have a high time complexity and poor classification performance. Motivated by this, an effective feature selection method, called supervised locally linear embedding and Spearman's rank correlation coefficient (SLLE-SC2), is proposed which is based on the concept of locally linear embedding and correlation coefficient algorithms. Supervised locally linear embedding takes into account class label in...
Source: Computational and Mathematical Methods in Medicine - April 19, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Prediction of GPCR-Ligand Binding Using Machine Learning Algorithms.
Authors: Seo S, Choi J, Ahn SK, Kim KW, Kim J, Choi J, Kim J, Ahn J Abstract We propose a novel method that predicts binding of G-protein coupled receptors (GPCRs) and ligands. The proposed method uses hub and cycle structures of ligands and amino acid motif sequences of GPCRs, rather than the 3D structure of a receptor or similarity of receptors or ligands. The experimental results show that these new features can be effective in predicting GPCR-ligand binding (average area under the curve [AUC] of 0.944), because they are thought to include hidden properties of good ligand-receptor binding. Using the proposed met...
Source: Computational and Mathematical Methods in Medicine - April 19, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Scenario Screen: A Dynamic and Context Dependent P300 Stimulator Screen Aimed at Wheelchair Navigation Control.
Authors: Piña-Ramirez O, Valdes-Cristerna R, Yanez-Suarez O Abstract P300 spellers have been widely modified to implement nonspelling tasks. In this work, we propose a "scenario" stimulation screen that is a P300 speller variation to command a wheelchair. Our approach utilized a stimulation screen with an image background (scenario snapshot for a wheelchair) and stimulation markers arranged asymmetrically over relevant landmarks, such as suitable paths, doors, windows, and wall signs. Other scenario stimulation screen features were green/blue stimulation marker color scheme, variable Interstimulus ...
Source: Computational and Mathematical Methods in Medicine - April 19, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Prediction of Pathological Subjects Using Genetic Algorithms.
Authors: Sari M, Tuna C Abstract This paper aims at estimating pathological subjects from a population through various physical information using genetic algorithm (GA). For comparison purposes, K-Means (KM) clustering algorithm has also been used for the estimation. Dataset consisting of some physical factors (age, weight, and height) and tibial rotation values was provided from the literature. Tibial rotation types are four groups as RTER, RTIR, LTER, and LTIR. Each tibial rotation group is divided into three types. Narrow (Type 1) and wide (Type 3) angular values were called pathological and normal (Type 2) angu...
Source: Computational and Mathematical Methods in Medicine - April 8, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research

Novel Signal Noise Reduction Method through Cluster Analysis, Applied to Photoplethysmography.
Authors: Waugh W, Allen J, Wightman J, Sims AJ, Beale TAW Abstract Physiological signals can often become contaminated by noise from a variety of origins. In this paper, an algorithm is described for the reduction of sporadic noise from a continuous periodic signal. The design can be used where a sample of a periodic signal is required, for example, when an average pulse is needed for pulse wave analysis and characterization. The algorithm is based on cluster analysis for selecting similar repetitions or pulses from a periodic single. This method selects individual pulses without noise, returns a clean pulse signal...
Source: Computational and Mathematical Methods in Medicine - April 8, 2018 Category: Statistics Tags: Comput Math Methods Med Source Type: research