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Micro-electrode array (MEA) electrophysiological signal analysis by descriptive stochastic tests of the probability density structure

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Research on biomedical engineering 2025年第2期41卷 1-13页

作者： Faria, Vinícius Naves Rezende Ramos, Marina Abadia Martinoia, Sérgio Destro-Filho, João-Batista Postgraduate Program in Electrical Engineering Universidade Federal de MG Uberlândia Brazil Postgraduate Program in Biomedical Sciences Universidade Federal de MG Uberlândia Brazil Division of Informatics Bioengineering Robotics and System Engineering Università Degli Studi Di Genova Genova Italy

Purpose: The primary objective of this study is to present, analyze, and quantitatively characterize the electrical signals obtained from neuronal cultures coupled to micro-electrode arrays (MEAs). Special attention is given to the temporal evolution of electrical activity across distinct geometric regions of the MEA devices. Methods: The proposed methodology involves signal acquisition, classical analysis based on spike and burst detection, and, critically, the characterization of the probability density structure of the signals. This is achieved through the quantification of Gaussianity—expressed as the percentage of segments non-Gaussian (PSNG)—and stationarity— expressed as the percentage of segments non-stationary (PSNE). Results: Initial analyses showed that first-order power spectral density quantifiers lacked the statistical robustness required to effectively describe the complex components of MEA signals. In contrast, PSNG and PSNE demonstrated strong potential in capturing the different stages of neuronal culture development. Cluster analysis further supported the discriminative capacity of these quantifiers. Conclusion: The phase corresponding to decreased neuronal activity and onset of cell death—a biologically critical stage—exhibited the strongest correlation among the studied variables. These results suggest a discernible biological organization and highlight the relevance of PSNG and PSNE as promising tools for assessing neuronal culture dynamics. © The Author(s), under exclusive licence to The Brazilian Society of biomedical engineering 2025.

关键词： Cell death

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Extracorporeal membrane oxygenation versus conventional therapy in patients with acute respiratory failure: systematic review with meta-analysis

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Research on biomedical engineering 2024年第3-4期40卷 835-849页

作者： de Souza, Daniel Baldoino Barreto, Cassiana Gabriela Lima Milagre, Selma Terezinha Pereira, Adriano Alves University Hospital of the Federal University of Santa Catarina Florianópolis Brazil Centre for Innovation and Technology Assessment in Health Faculty of Electrical Engineering Postgraduate Program in Electrical and Biomedical Engineering Federal University of Uberlândia Uberlândia Brazil

Background: Acute respiratory distress syndrome (ARDS) is a severe condition where lung alveoli fill with fluid, depriving organs of oxygen and risking death. Mechanical ventilation is conventional for oxygen therapy, but extracorporeal membrane oxygenation (ECMO) may be needed for refractory ARDS cases. This study aims to compare ECMO's impact on mortality and hospital stay versus conventional treatment for patients aged 12 or older with moderate or severe ARDS in intensive care units (ICUs). Methodology: Four independent reviewers followed the PRISMA-P method for the review. The key question used the PICOS tool. Databases searched included Cochrane Library, Bireme, MEDLINE, EMBASE, Web of Science, Scielo, LILACS, and grey literature to minimize publication bias. Selected papers were randomized controlled trials (RCTs) without language restrictions, meeting predefined inclusion and exclusion criteria. RoB-2 assessed bias risk, and GRADE evaluated evidence quality. Mortality was analyzed using a fixed-effect PETO method (odds ratio), and hospital stay was treated as a continuous variable using inverse variance and standardized mean difference (SMD). Results: We found 3,774 articles and selected 6 studies with 1,050 participants. Of these, 519 were allocated to the intervention group (ECMO) and 531 to the conventional treatment group (MV). The risk of bias for 3 studies was "some concerns," and 3 were "high risk of bias," mainly due to "deviations from intended/planned interventions" and "selection of reported outcomes." The primary outcomes for 30-day, 60-day, 90-day, and 180-day mortality showed odds ratios of 0.90 (95% CI: 0.66–1.21), 0.78 (95% CI: 0.50–1.21), 0.90 (95% CI: 0.66–1.21), and 0.62 (95% CI: 0.36–1.06) respectively, with low heterogeneity (I2 0.10). The secondary outcomes for a total length of stay and ICU stay showed standardized mean differences of 0.39 (95% CI: 0.13–0.65) and 0.33 (95% CI: 0.05–0.60) respectively, with substantial heterogeneity (I2

关键词： Risk assessment

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Control engineering investigation of the effects of proliferative diabetic retinopathy on the crystalline lens and ciliary muscle dynamic behavior

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Research on biomedical engineering 2023年第3期39卷 663-676页

作者： Oliveira, Rebeca Hannah de M. Silva, Mayla dos S. Nunes, Gustavo A. M. A. Faria, Rafael Mendes Santos, Kleriston Silva Rosa, Leandro L. F. Rosa, Mário F. F. Rosa, Suélia de S. R. F. Department of Biomedical Engineering Johns Hopkins University School of Medicine BaltimoreMD United States Postgraduate Program in Mechatronic Systems University of Brasília DF Brasilia Brazil Optometry Clinic GO Goiânia Brazil Biomedical Engineering Graduate Program University of Brasília DF Brasilia Brazil University of Brasilia – UnB DF Brasilia Brazil

Purpose: Proliferative diabetic retinopathy (PDR) affects more than 100 million adults worldwide and is one of the primary diseases leading to blindness and affecting the eye’s retina. Few papers mention its impact on the anterior segment of the eye. Methods: We present a novel bond graph model of the human eye calibrated with data from the literature to simulate the effects of retinopathy on lens behavior. Through mathematical representation in state space and transfer functions, we simulate the dynamic responses of the physiological and pathological systems. Results: The dynamic response to impulse inputs shows a distinct peak amplitude (0.01 difference) and transient time (0.0001 s) for PDR and Healthy systems at Region B (lens and ciliary muscle). Qualitative increase in ocular vasculature aggravation attenuates PDR dynamic response to unitary step input compared to Healthy (50% decay at 20 days of simulation) at Region B. Conclusions: The model suggests the potential impact of PDR on ciliary muscle behavior, which can have a clinical translation on diagnosis, follow-up, and treatment of the disease. It can be used for future studies on the effects of retinopathy on different ocular regions. © 2023, The Author(s), under exclusive licence to The Brazilian Society of biomedical engineering.

关键词： Eye protection

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A novel methodology based on static visual stimuli and kinesthetic motor imagery for upper limb neurorehabilitation

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Research on biomedical engineering 2024年第3-4期40卷 687-700页

作者： Bastos-Filho, T.F. Villa-Parra, A.C. Guerrero-Méndez, C.D. González-Cely, A.X. Blanco-Díaz, C.F. Delisle-Rodríguez, D. Igasaki, T. Vitoria Brazil Biomedical Engineering Research Group Salesian Polytechnic University Cuenca Ecuador Postgraduate Program in Neuroengineering Edmond and Lily Safra International Institute of Neurosciences Santos Dumont Institute Macaiba Brazil Faculty of Advanced Science and Technology Kumamoto University Kumamoto Japan

Purpose: This work proposes a protocol to be used in a Brain-Computer Interface (BCI) for hand and finger movement rehabilitation aimed at post-stroke patients. This strategy is based on Electroencephalography (EEG) and uses concepts of both Static Visual Stimuli (SVS) of the own subject’s hand (OwnSVS) and Kinesthetic Motor Imagery (KMI) to improve the motor task recognition of the same limb. Methods: The protocol proposed here takes into account several aspects, such as physical rehabilitation strategies, Active Hand Orthosis (AHO) — represented by a robotic glove —, and the acquisition of the EEG signal over the brain motor area. Power Spectral Density (PSD) and Riemannian Geometry (RG) are used for feature extraction in this work, considering Mu (μ, 8–12 Hz), Low-Beta (Low-β, 13–17 Hz) and High-Beta (High-β, 18–24 Hz) frequency bands. Moreover, a feature selection stage using Pair-Wise Feature Proximity (PWFP) is also used before input to a Machine Learning (ML) classifier. Here, Linear Discriminant Analysis (LDA), Support Vector Machine (SVM), k-Nearest Neighbors (kNN), and Decision Tree (DT) are compared. Results: As results, evaluated in 10 healthy subjects, features using PSD-PWFP and kNN achieved a maximum ACC of 89.81% (with AHO movements), improving by 3% the standard protocol (without AHO movements). Conclusions: The findings of this work indicate that AHO movement assistance can improve the recognition of hand opening and closing MI tasks, which can be implemented in the design of robotic BCI controllers for hand and finger movement neurorehabilitation in stroke patients. © The Author(s), under exclusive licence to The Brazilian Society of biomedical engineering 2024.

关键词： Electroencephalography

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Effect of exposure to a light-emitting diode (LED) on the physicochemical characteristics of natural latex biomembranes used to treat diabetic ulcers

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Research on biomedical engineering 2022年第3期38卷 901-911页

作者： Santana, Thamis Fernandes Oliveira, Rebeca Hannah de Melo dos Santos, Ludmila Evangelista Lima, Eunice Paloma Nascimento Faria, Sylvia de Sousa Fonseca, Marcos Augusto Moutinho da Silva, Jaqueline Rodrigues Tatmatsu-Rocha, José Carlos Gomes, Marília Miranda Forte Fleury Rosa, Mário Fabrício Fleury Rosa, Suélia de Siqueira Rodrigues Carneiro, Marcella Lemos Brettas Postgraduate Program in Biomedical Engineering University of Brasilia Federal District Brasilia Brazil Postgraduate Program in Materials Science and Engineering Federal University of Campina Grande Paraiba Campina Grande Brazil Department of Electrical Engineering University of Brasilia Federal District Brasilia Brazil Postgraduate Program in Biology Animal University of Brasilia Federal District Brasilia Brazil Medicine Faculty Physical Therapy Department Federal University of Ceara Ceara Fortaleza Brazil Postgraduate Technology and Health Program University of Brasília Federal District Brasília Brazil

Purpose: Natural latex biomembrane has shown high therapeutic potential for the treatment of diabetic ulcers when associated with phototherapy. In this study, physical and chemical alterations in the latex biomembranes were evaluated after exposure to light-emitting diode (LED) irradiation and after contact with NaCl solution. Methods: There were three experimental groups: natural latex biomembranes (1) in natura;(2) after 35 min of LED light irradiation;and (3) after immersion in NaCl 0.9 g% solution. The samples were analyzed by tensile strength test, thermogravimetry, contact angle wettability, and Fourier-transform infrared spectroscopy. Results: The biomembranes that were submitted to contact with NaCl aqueous solution or exposure to LED did not undergo impairment of mechanical resistance. The thermogravimetry analysis indicated that increasing temperature led to mass loss in all samples, referring to their decomposition temperatures. In the wettability test, biomembranes exposed to LED showed a significant reduction in the contact angle between 0 and 10 min, indicating an increase in hydrophilicity, suggesting water storage capacity. The Fourier-transform infrared spectrometry assay showed that there was a more significant reduction in vibration intensity after immersion in NaCl solution compared to untreated biomembranes. An increase in the intensity of the entire spectrum of biomembranes exposed to LED was observed in comparison with the other samples, which may be related to photodegradation caused by LED light irradiation. Conclusion: The biomembranes underwent significant changes in its chemical structure after being subjected to different types of exposure and maintained its elasticity and tensile strength properties, in addition to showing good water retention capacity after exposure to LED. Thus, it maintains many of its properties for application as a tissue-regenerating biomaterial, even when subjected to LED irradiation and a humid environment. © 20

关键词： Tissue regeneration

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Analysis of Brain Excitability After Transcranial Direct Current Stimulation and Brain-Computer Interface Based on Motor Imagery on a Post-stroke Patient 9th

Analysis of Brain Excitability After Transcranial Direct Cu...

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9th Latin American Congress on biomedical engineering, CLAIB 2022 and 28th Brazilian Congress on biomedical engineering, CBEB 2022

作者： Silva, Leticia Lima, Jéssica Schreider, Sheila Delisle-Rodriguez, Denis Krishnan, Sridhar Bastos-Filho, Teodiano Postgraduate Program in Electrical Engineering Universidade Federal do Espirito Santo Vitoria Brazil Postgraduate Program in Biotechnology Universidade Federal do Espirito Santo Vitoria Brazil Edmond and Lily Safra International Institute of Neurosciences Instituto Santos Dumont Macaiba Brazil Department of Electrical Computer and Biomedical Engineering Toronto Metropolitan University Toronto Canada

ISBN: (纸本)9783031494062

Stroke is a neurological syndrome that may cause severe cognitive and motor impairments for survival. Alternative rehabilitation techniques have been developed to recover lower-limb movements and gait of post-stroke patients, such as Motor Imagery (MI)-based Brain-Computer Interfaces (BCIs), Virtual Reality (VR), and robotic devices. Transcranial Direct Current Stimulation (tDCS) is a non-invasive technique to stimulate the brain and modulate cortical excitability. This study aims to analyze the short-term effects of tDCS compared to sham stimulation before a lower-limb MI-BCI pedaling training (through a robotic monocycle) task in a patient with subacute stroke. We studied a post-stroke patient with 2 months of ischemic stroke and right hemiparesis who was submitted to the following tasks: active pedaling, sham tDCS and MI-BCI, and tDCS and MI-BCI. We evaluated the relative power around the foot area (Cz electrode), and a significant (p-value © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Brain computer interface

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Understanding Acoustic Phenomena in Stenosed Coronary Arteries through Bond Graph Modeling of Sound Generation 46

Understanding Acoustic Phenomena in Stenosed Coronary Arteri...

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46th Annual International Conference of the IEEE engineering in Medicine and Biology Society, EMBC 2024

作者： Sandoval, Loreto Rojas Ulloa, René Araya Da Silva, Ana Karoline Almeida De Almeida Nunes, Gustavo Adolfo Marcelino Faria, Rafael Mendes Sepúlveda, José Parra Da Costa, Lindemberg Barreto Mota Acevedo, Luca Rubilar Rosa, Mário Fabrício Fleury Pino, Esteban J. De Siqueira Rodrigues Fleury Rosa, Suélia Universidad de Concepción Electrical Engineering Department Chile University of Brasilia Mechanical Engineering Department Distrito Federal Brasilia70910-900 Brazil University of Brasilia Postgraduate Program in Biomedical Engineering Distrito Federal Brasilia70910-900 Brazil

ISBN: (纸本)9798350371499

Coronary artery stenosis is characterized by the obstruction or narrowing of coronary arteries, impairing blood flow to the cardiac muscle. Cardiovascular diseases rank among the leading global causes of death. Understanding the mechanisms, risk factors, and impacts of coronary artery stenosis (CAD) is essential for developing effective strategies for prevention, early diagnosis, and treatment, aiming to enhance cardiovascular health and reduce adverse consequences associated with this condition. Previous studies explore the potential of acoustic devices in non-invasive CAD detection through the analysis of cardiac sounds. A theoretical model utilized a cardiac microphone and signal processing to generate sounds in partially obstructed coronary arteries. Emphasizing the model's sensitivity to geometric and dynamic parameters, this article integrates Bond Graph (BG) models into the analog sound circuit, aiming to develop a dynamic representation of biological processes in complex systems like coronary arteries. This research seeks to construct a comprehensive mathematical model using a state-space approach to enhance understanding, diagnostics, and interventions in cardiovascular conditions. The utilization of BG demonstrated notable similarity to the pathology of the disease, providing an accurate representation of its effects. The model's sensitivity to geometric and dynamic parameters allowed an in-depth understanding of the specific physiological characteristics of the disease, highlighting its ability to reproduce patterns observed in patients with CAD. © 2024 IEEE.

关键词： Diagnosis

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Evaluation of fluoride concentration in toothpastes with antimicrobial molecules commercialized in Brazil

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Research on biomedical engineering 2021年第1期37卷 9-14页

作者： Medeiros, Maria da Conceição de Araújo Valadas, Lídia Audrey Rocha Lotif, Mara Assef Leitão Bottenberg, Peter Marciano, Fernanda Roberta Biomedical Engineering Postgraduate Program Brazil University São Paulo Brazil Development and Technological Innovation in Medicines Postgraduate Program Federal University of Ceara Fortaleza Brazil Brussels Belgium

Purpose: This study aimed to analyze the fluoride concentrations in different dentifrices with antimicrobial and natural molecules marketed in Brazil. Thus, 12 dentifrices were selected to be analyzed for the concentration of total fluoride (TF), total soluble fluoride (TSF) and ionizable fluoride (IF). Methods: Two tubes of each brand were purchased at different locations. The samples were analyzed in duplicates using an ion-specific electrode and the concentrations were determined in μg F/g. Results: The TF of all calcium carbonate dentifrices showed averages below 1500 ppm F. Regarding TSF, only one toothpaste had an average above 1000 ppm F−, while the IF values were almost 500 ppm F. In the analysis of fluoride in dentifrices which present silica as abrasive, the TF presented averages below 1500 ppm F, while the TSF all presented averages close to 1000 ppm F−, and the IF values varied from close to 500 ppm to more than 1000 ppm F. In dentifrices whose formulation contained calcium carbonate associated with silica or other formulations such as sodium bicarbonate, the TF, TSF, and IF values were all above 1000 ppm F. Conclusion: The evaluated dentifrices generally showed TF concentrations lower than those declared on the packaging;however, the TSF content remained close to 1000 ppm F. It can be concluded that the analyzed dentifrices with antimicrobial molecules showed values close to those suggested regarding anti-caries effect. © 2020, Sociedade Brasileira de Engenharia Biomedica.

关键词： Calcium carbonate

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HIFU thermal lesion difference between simulated human phantom and tissue-mimicking phantom 24

HIFU thermal lesion difference between simulated human phant...

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24th International Congress on Acoustics, ICA 2022

作者： Kim, Seong Chan Choi, Min Joo Jeju National University Interdisciplinary Postgraduate Program of Biomedical Engineering Korea Republic of Jeju National University School of Medicine Korea Republic of

Most HIFU procedures use the thermal effect of ultrasound, and information about temperature is directly related to the effect and side effects of the procedure. In the case of the human body, there are complex structures including bones around the target tissue to be irradiated with ultrasound. Thermal lesions in human tissue differ from thermal lesions in ideal conditions due to the standing waves generated by the target tissue and surrounding structures. If a high temperature rise is induced at a location other than the focal point of the HIFU, side effects of the procedure and patient safety may be threatened. In this study, two conditions were simulated, a tissue-mimicking phantom and a human body, in order to compare differences in thermal lesions. In the simulation results, the shape of the thermal lesion generated in the two conditions was not the same, and there was a difference in the location where the temperature was increased. © ICA *** rights reserved

关键词： HIFU Human phantom Thermal lesion Tissue mimicking phantom

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Computational Modeling of the Pendulum Test to Simulate Spasticity in the Elbow Joint 9th

Computational Modeling of the Pendulum Test to Simulate Spas...

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9th Latin American Congress on biomedical engineering, CLAIB 2022 and 28th Brazilian Congress on biomedical engineering, CBEB 2022

作者： Pasqualin, B.R. Silva, V.A. Orselli, M.I.V. Manffra, E.F. Pontifícia Universidade Católica do Paraná Biomedical Engineering Curitiba Brazil Pontifícia Universidade Católica do Paraná Postgraduate Program in Health Technology Curitiba Brazil Instituto Vita São Paulo Brazil

ISBN: (纸本)9783031494062

Computational models have been developed to help understand phenomena such as spasticity. In this study, we aim to develop a computational model using the Matlab-OpenSim interface to simulate the passive pendulum test in the elbow joint and evaluate whether the input of a neural excitation pattern with spasticity in the model would be sufficient to reproduce an altered kinematic pattern during an elbow pendulum test. We built a model with two segments that represent the humerus and radius bones, added two actuators to represent the biceps and triceps muscles, and the excitation values were obtained from the electromyography signal available in the literature. For the first simulation we used the electromyography (EMG) signal from a non-spastic person and for the last simulation was used the excitation values from a person with mild spasticity. Our results showed that it is possible to reproduce the pendulum test at the elbow joint, but modifications in the model are necessary to better reproduce the movement. © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： MATLAB

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