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Performance of atrial conduction velocity algorithms with error-prone clinical measurements for the identification of atrial fibrosis

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Computers in Biology and Medicine 2025年 191卷 110119-110119页

作者： Gharaviri, Ali Vigneswaran, Vinush Vickneson, Keeran Roney, Caroline Corrado, Cesare Coveney, Sam Maciunas, Kestutis Bodagh, Neil Klis, Magda Kotadia, Irum Sim, Iain Whitaker, John Bishop, Martin Niederer, Steven O'Neill, Mark Williams, Steven E. Centre for Cardiovascular Science The University of Edinburgh United Kingdom School of Biomedical Engineering and Imaging Sciences King's College London United Kingdom School of Engineering and Materials Science Queen Mary University of London United Kingdom National Heart & Lung Institute - Faculty of Medicine Imperial College London United Kingdom Heart Rhythm Research Brussels Postgraduate Program in Cardiac Electrophysiology and Pacing Vrije Universiteit Brussel Brussels Belgium Heart Rhythm Management Centre Universitair Ziekenhuis Brussel Brussels Belgium Brussels1050 Belgium

Introduction: Measuring conduction velocity, as a direct consequence of fibrosis, may provide a better method to localise fibrotic regions. This study aims to assess established cardiac conduction velocity calculation methods (Triangulation, Polynomial Surface Fitting, and Radial Basis Function) in identifying areas of conduction slowing caused by fibrosis, considering realistic measurement errors. Method: Using a human left atrium computational model, atrial activation was simulated. Each conduction velocity calculation method's performance was evaluated under uncertainties in mapping point density, local activation time assignment and electrode locations by comparing calculated conduction velocity to ground truth conduction velocity derived from high-resolution simulated atrial activation. Results: All methods agreed well with ground truth conduction velocity maps in noise-free, high-density sampling conditions. However, Triangulation and Polynomial Surface Fitting methods showed susceptibility to noise, exhibiting significant errors under moderate to high noise levels. Radial Basis Function method demonstrated greater robustness to noise and reduced sampling density. Fibrotic region identification accuracy was high under ideal conditions for all methods but declined with increasing noise, with the Radial Basis Function method maintaining superior performance. Conclusion: While all methods accurately estimate conduction velocity under ideal conditions, the Radial Basis Function method shows robustness to a realistic clinical noise, hence making it the most suitable to identify fibrotic regions. © 2025

关键词： Triangulation

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Metrological control of electrolytic sensors for measuring angular deviations: Application in monitoring displacements of engineering structures 10

Metrological control of electrolytic sensors for measuring a...

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10th Brazilian Congress on Metrology, Metrologia 2019

作者： Leaño, E.G. Filho, P. Rocha Hernández, J.D. Frota, M.N. Civil Engineering Depart. Pontifical Catholic University of Rio de Janeiro RJ22451-900 Brazil Postgraduate Programme in Metrology Metrology for Quality and Innovation Pontifical Catholic University of Rio de Janeiro Rio de Janeiro22451-900 Brazil Research Group GIFOURIER. Faculty of Mechanical Electronic and Biomedical Engineering. Mechanical Engineering Program University Antonio Nariño Puerto Colombia Colombia

The work evaluates the metrological reliability of electrolytic sensors (electrolevels) used to determine angular deviations of elements of engineering structures. The motivation for the work resulted from its strategic application to control the stability of civil engineering structures, notably with application in geotechnics (e.g.: different types of dams of interest in engineering). The methodology used is based on the metrological consistency associated with the quality control process of a set of electrolevels submitted, simultaneously, to a careful calibration process, with traceability ensured to a standard angular deviation pattern. Mounted on a rigid bar, but pivoted at one of its ends to allow angular displacements, the output of each electrolevel is compared with the previously calibrated standard, for different controlled conditions of angular deviation imposed on the bar articulated to a center of rotation. The result of the analysis of typical calibration data for nine electrolevels allowed to show that the expression of the uncertainties associated with the calibration measurements performed constitutes an essential foundation to ensure the metrological reliability of the electrolevels, having allowed to validate a method of discard of electrolevels not meeting the allowable tolerance for a specific engineering application. Among the conclusions of the work, it was possible to qualify the statistical treatment of the levels of uncertainty as a sufficiently robust strategy to validate the electrolevels as a reliable instrument for angular displacement measurements, with a level of confidence appropriate to its application in civil engineering. © 2021 Institute of Physics Publishing. All rights reserved.

关键词： Uncertainty analysis

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Structural validation of the “Teacher’s report form” attention problems scale in a Brazilian sample

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Measurement Instruments for the Social Sciences 2021年第1期3卷 1-9页

作者： Pires, Thiago Rocha, Marina Assis, Simone Nobre, Flavio Department of Studies on Violence and Health National School of Public Health (Fiocruz) Rio de Janeiro Brazil Postgraduate Program in Developmental Disorders Universidade Presbiteriana Mackenzie Sao Paulo Brazil Neurology Postgraduate Program University Hospital Gaffrée and Guinle (Unirio) Rio de Janeiro Brazil Biomedical Engineering Program/ COPPE Department Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil

Attention deficit hyperactivity disorder is one of the most common childhood neurodevelopmental syndromes. Although clinical evaluation is considered the gold standard in diagnosing psychiatric disorders, in epidemiological studies, this evaluation is rarely used for practical and financial reasons. Instead, psychometric instruments are used to screen for the disorders. In this case, it is essential to investigate whether these instruments are suitable for measuring the proposed problem. This study aims to verify the structural validation of the Attention Problems Scale of the Teacher’s Report Form (TRF). A random sample of 445 TRF filled out by the teacher of children from São Gonçalo/RJ was selected. The confirmatory factor analysis was applied to validate some factor structures that have been raised in the literature. A second aspect analyzed was the use of structural equation models to verify the validated factorial structure’s relationship with some comorbidities. The bifactor model was the most suitable to explain the TRF child’s Attention Problems Scale’s factor structure. It presented the best-fit quality scores for confirmatory factor analysis than other tested structures. Although it presented good indicators for structural validity, some symptoms could be reassessed to have a more consistent instrument. The bifactor model as an explanatory structure in SEM was able to predict important mental health outcomes. These results are an additional validation to the bifactor model. The results suggest the validity of the TRF’s Attention Problems Scale. The instrument’s factor structure was also appropriate because it corroborated most of the association’s assumptions between subtypes of attention problems and other aspects of mental health. The existence of screening scales adapted to Brazilian Portuguese can substantially impact many children who have difficulty learning. Also, the screening scales can be a useful tool for the health sector to facilitate referra

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Optimal Strategy to Reduce Energy Waste in an Electricity Distribution Network Through Direct/Indirect Bulk Load Control

SSRN

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SSRN 2023年

作者： Cerna, Fernando Vladimir Dantas, Jamile T. Naderi, Ehsan Contreras, Javier Department of Electrical Engineering Federal University of Roraima Boa Vista69310-000 Brazil Postgraduate Program in Natural Resources Research Area in Management and Dynamics of Natural Resources – Renewable Energies Federal University of Roraima Av. Nova Iorque – Aeroporto Boa Vista69310-000 Brazil School of Electrical Computer and Biomedical Engineering Southern Illinois University CarbondaleIL62901 United States School of Industrial Engineering University of Castilla-La Mancha Ciudad Real13071 Spain

In recent decades, the ever-increasing demand for electricity in large cities is leading the electricity distribution network (EDN) to an operational state of fatigue, especially at peak load times. Thus, the lifetime of feeders, transformers, circuit breakers, among others, can be compromised. In this context, load congestion, technical losses, and voltage deviations across the EDN can contribute to the high waste of electricity as well as to the worsening of the supply service. To face this problem, this paper proposes a mixed integer linear programming (MILP) model that aims to reshape the demand profile (i.e., load reduction in peak periods without load rebound in the remaining periods of the day) of total consumers while the voltage deviations and technical losses are minimized. In the proposed model, the demand profile reshaping is carried out through direct (DC) and indirect (IC) bulk control of residential, commercial, and industrial loads, while the load factor (LF), i.e., indicator related to the efficient use of electricity, is improved. Due to the scheduling of these loads at certain times of the day, the occurrence of voltage deviations and technical losses can be mitigated by the efficient control of capacitor banks (CBs). © 2023, The Authors. All rights reserved.

关键词： Electric circuit breakers

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Cognitive disorder and dementia in type 2 diabetes mellitus

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World Journal of Diabetes 2022年第4期13卷 319-337页

作者： Genaro G Ortiz Miguel Huerta Héctor A González-Usigli Erandis D Torres-Sánchez Daniela LC Delgado-Lara Fermín P Pacheco-Moisés Mario A Mireles-Ramírez Blanca MG Torres-Mendoza Roxana I Moreno-Cih Irma E Velázquez-Brizuela Department of Philosophical and Methodological Disciplines University Health Sciences CenterUniversity of GuadalajaraGuadalajara 44340JaliscoMexico Department of Neurology Movement Disorders ClinicSub-Specialty Medical UnitNational Western Medical CenterMexican Social Security Institute(IMSS)Guadalajara 44340JaliscoMexico University Biomedical Research Center University of ColimaColima 28040Mexico Department of Medical and Life Sciences University Center of‘La Ciénega’University of GuadalajaraOcotlán 47810JaliscoMexico Department of Chemistry University Center of Exact Sciences and EngineeringUniversity of GuadalajaraGuadalajara 44340JaliscoMexico Division of Neurosciences Western Biomedical Research CenterMexican Social Security Institute(IMSS)Guadalajara 44340JaliscoMexico Gerontology Postgraduate Program Public Health DepartmentUniversity Health Sciences CenterUniversity of GuadalajaraGuadalajara 44340JaliscoMexico

Insulin,a key pleiotropic hormone,regulates metabolism through several signaling pathways in target tissues including skeletal muscle,liver,and *** the brain,insulin modulates learning and memory,and impaired insulin signaling is associated with metabolic dysregulation and neurodegenerative *** the receptor level,in aging and Alzheimer’s disease(AD)models,the amount of insulin receptors and their functions are *** and animal model studies suggest that memory improvements are due to changes in insulin ***,diabetes mellitus(DM)and insulin resistance are associated with age-related cognitive decline,increased levels ofβ-amyloid peptide,phosphorylation of tau protein;oxidative stress,pro-inflammatory cytokine production and dyslipidemia. Recent evidence shows that deleting brain insulin receptors leads to mildobesity and insulin resistance without influencing brain size and apoptosis ***, deleting insulin-like growth factor 1 receptor (IGF-1R) affects brain size anddevelopment, and contributes to behavior changes. Insulin is synthesized locally in the brain andis released from the neurons. Here, we reviewed proposed pathophysiological hypotheses toexplain increased risk of dementia in the presence of DM. Regardless of the exact sequence ofevents leading to neurodegeneration, there is strong evidence that mitochondrial dysfunctionplays a key role in AD and DM. A triple transgenic mouse model of AD showed mitochondrialdysfunction, oxidative stress, and loss of synaptic integrity. These alterations are comparable tothose induced in wild-type mice treated with sucrose, which is consistent with the proposal thatmitochondrial alterations are associated with DM and contribute to AD development. Alterationsin insulin/IGF-1 signaling in DM could lead to mitochondrial dysfunction and low antioxidantcapacity of the cell. Thus, insulin/IGF-1 signaling is important for increased neural processing andsystemic metabolism, a

关键词： Alzheimer´s disease Diabetes mellitus Insulin Vascular dementia Cognitive decline

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Reducing VNS stimulation parameters: Is it safe?

Arquivos Brasileiros de Neurocirurgia: Brazilian Neurosurger...

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Arquivos Brasileiros de Neurocirurgia: Brazilian Neurosurgery 2022年第1期41卷 e19-e25页

作者： Tatiana Von Hertwig Fernandes de Oliveira Jennyfer Paulla Galdino Chaves Thiago Teixeira Silva Alexandre Novicki Francisco Sérgio Leandro Stebel Department of Neurosurgery Cajuru University Hospital Curitiba PR Brasil Postgraduate Program in Biomedical Engineering Federal University of Technology Curitiba PR Brasil

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Evaluation of occupational doses in surgical staff via Monte Carlo simulation

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Applied Radiation and Isotopes 2025年 224卷 111894页

作者： Machado, Karen L. Maschio, Alessa Guimarães, Guilherme B. Santos, William S. Neves, Lucio P. Perini, Ana P. Postgraduate Program in Biomedical Engineering of Federal University of Uberlândia MG Uberlândia Brazil Institute of Physics of Federal University of Uberlândia MG Uberlândia Brazil Federal University of Sergipe Center for Exact Sciences and Technology Department of Physics SE São Cristóvão Brazil

This study evaluated radiation exposure during fluoroscopy-guided surgical procedures using Monte Carlo simulations. The methodology involved modeling femoral osteosynthesis scenarios, representing both the patient and the occupationally exposed individual (OEI) with a female reference phantom from ICRP Publication 145. The study included 24 simulations, categorized into posteroanterior (PA) and lateral cross (LC) projections, with tube voltages ranging from 60 to 90 kV for PA and 70 to 100 kV for LC. Protective equipment, such as aprons, suspended glass, and curtains, was tested using alternative materials to lead, including bismuth and tungsten. The results demonstrated that bismuth and tungsten exhibited varying levels of radiation attenuation efficiency compared to lead, with performance expressed as percentages relative to lead-based equipment. While certain scenarios showed that bismuth and tungsten outperformed lead in radiation protection, other scenarios highlighted their limitations. For instance, at 90 kV in the PA projection, both materials resulted in significant increases in radiation dose compared to lead. © 2025 Elsevier Ltd

关键词： Reactor shielding

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Load Factor Improvement of the Electricity Grid Considering Distributed Resources Operation and Regulation of Peak Load

SSRN

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SSRN 2022年

作者： Cerna, Fernando Vladimir Naderi, Ehsan Marzband, Mousa Contreras, Javier Coêlho, John K. Fantesia, Maurício P. Department of Electrical Engineering Federal University of Roraima Boa Vista69310-000 Brazil Postgraduate Program in Natural Resources Research Area in Management and Dynamics of Natural Resources – Renewable Energies Federal University of Roraima Av. Nova Iorque – Aeroporto Boa Vista69310-000 Brazil School of Electrical Computer and Biomedical Engineering Southern Illinois University CarbondaleIL62901 United States Department of Mathematics Physics and Electrical Engineering Faculty of Engineering and Environment Northumbria University Newcastle upon TyneNE1 8ST United Kingdom School of Industrial Engineering University of Castilla-La Mancha Ciudad Real13071 Spain

The load factor (LF) of an electricity network (EN) is an indicator related to the efficient electricity usage within a time horizon (e.g., day, month, year, etc.). LF improvement can be achieved through an efficient operational scheme that combines several strategies. Among them, peak load regulation in the demand profile of all the consumers together with the operation of distributed resources (DREs), such as renewable sources (RSs) and capacitor banks (CBs) represents a promising alternative. To address this efficient scheme, this work proposes a mixed-integer linear programming (MILP) model that aims to increase the LF through the bulk scheduling of residential, commercial, and industrial electrical appliances during the day, considering a baseline demand and an hourly rate. At the same time, voltage fluctuations and technical losses are mitigated by the presence of DREs in the EN. Operational constraints related to the performance of EN, RSs, and CBs are considered. Uncertainties in the habitual demand profiles and solar radiation incidence during the day are represent through simulation algorithms. In order to evaluate our proposal, a modified 14-node IEEE EN was used. The results corroborate the applicability of this proposed MILP model, reducing electricity waste and ensuring the efficient EN operation. © 2022, The Authors. All rights reserved.

关键词： Integer programming

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Load Factor Improvement of the Electricity Grid Considering Distributed Resources Operation and Regulation of Peak Load

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SSRN 2022年

关键词： Integer programming

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Shoulder Flexion Pre-Movement Recognition Through Subject-Specific Brain Regions to Command an Upper Limb Exoskeleton

Shoulder Flexion Pre-Movement Recognition Through Subject-Sp...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： Yunier Prieur-Coloma Denis Delisle-Rodríguez Leondry Mayeta-Revilla Dharmendra Gurve Ramón A. Reinoso-Leblanch Alberto López-Delis Teodiano Bastos Sri Krishnan Adson F. da Rocha Center of Medical Biophysics University of Oriente Cuba Postgraduate Program in Electrical Engineering Federal University of Espirito Santo Brazil Department of Biomedical Engineering University of Oriente Cuba Department of Electrical Computer and Biomedical Engineering Ryerson University Toronto Canada Department of Electrical Engineering University of Brasilia Brasilia Brasil

ISBN: (数字)9781728119908

ISBN: (纸本)9781728119915

This work presents two brain-computer interfaces (BCIs) for shoulder pre-movement recognition using: 1) manual strategy for Electroencephalography (EEG) channels selection, and 2) subject-specific channels selection by applying non-negative factorization matrix (NMF). Besides, the proposed BCIs compute spatial features extracted from filtered EEG signals through Riemannian covariance matrices and a linear discriminant analysis (LDA) to discriminate both shoulder pre-movement and rest states. We studied on twenty-one healthy subjects different frequency ranges looking the best frequency band for shoulder pre-movement recognition. As a result, our BCI located automatically EEG channels on the contralateral moved limb, and enhancing the pre-movement recognition (ACC = 71.39 ± 12.68%, κ = 0.43 ± 0.25%). The ability of the proposed BCIs to select specific EEG locations more cortically related to the moved limb could benefit the neuro-rehabilitation process.

关键词： Electroencephalography Manuals Covariance matrices Shoulder Frequency measurement Exoskeletons Brain-computer interfaces

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