Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
1.
Sensors (Basel) ; 23(13)2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37447686

RESUMO

The present study introduces a brain-computer interface designed and prototyped to be wearable and usable in daily life. Eight dry electroencephalographic sensors were adopted to acquire the brain activity associated with motor imagery. Multimodal feedback in extended reality was exploited to improve the online detection of neurological phenomena. Twenty-seven healthy subjects used the proposed system in five sessions to investigate the effects of feedback on motor imagery. The sample was divided into two equal-sized groups: a "neurofeedback" group, which performed motor imagery while receiving feedback, and a "control" group, which performed motor imagery with no feedback. Questionnaires were administered to participants aiming to investigate the usability of the proposed system and an individual's ability to imagine movements. The highest mean classification accuracy across the subjects of the control group was about 62% with 3% associated type A uncertainty, and it was 69% with 3% uncertainty for the neurofeedback group. Moreover, the results in some cases were significantly higher for the neurofeedback group. The perceived usability by all participants was high. Overall, the study aimed at highlighting the advantages and the pitfalls of using a wearable brain-computer interface with dry sensors. Notably, this technology can be adopted for safe and economically viable tele-rehabilitation.


Assuntos
Interfaces Cérebro-Computador , Telerreabilitação , Dispositivos Eletrônicos Vestíveis , Humanos , Eletroencefalografia/métodos , Imagens, Psicoterapia/métodos
2.
J Neural Eng ; 19(3)2022 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-35640554

RESUMO

Objective.Processing strategies are analyzed with respect to the classification of electroencephalographic signals related to brain-computer interfaces (BCIs) based on motor imagery (MI). A review of literature is carried out to understand the achievements in MI classification, the most promising trends, and the challenges in replicating these results. Main focus is placed on performance by means of a rigorous metrological analysis carried out in compliance with the international vocabulary of metrology. Hence, classification accuracy and its uncertainty are considered, as well as repeatability and reproducibility.Approach.The paper works included in the review concern the classification of electroencephalographic signals in motor-imagery-based BCIs. Article search was carried out in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses standard and 89 studies were included.Main results.Statistically-based analyses show that brain-inspired approaches are increasingly proposed, and that these are particularly successful in discriminating against multiple classes. Notably, many proposals involve convolutional neural networks. Instead, classical machine learning approaches are still effective for binary classifications. Many proposals combine common spatial pattern, least absolute shrinkage and selection operator, and support vector machines. Regarding reported classification accuracies, performance above the upper quartile is in the 85%-100% range for the binary case and in the 83%-93% range for multi-class one. Associated uncertainties are up to 6% while repeatability for a predetermined dataset is up to 8%. Reproducibility assessment was instead prevented by lack of standardization in experiments.Significance.By relying on the analyzed studies, the reader is guided towards the development of a successful processing strategy as a crucial part of a BCI. Moreover, it is suggested that future studies should extend these approaches on data from more subjects and with custom experiments, even by investigating online operation. This would also enable the quantification of the results reproducibility.


Assuntos
Interfaces Cérebro-Computador , Algoritmos , Eletroencefalografia/métodos , Humanos , Imaginação , Movimento , Reprodutibilidade dos Testes
3.
J Multidiscip Healthc ; 15: 815-824, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35480063

RESUMO

Systemic sclerosis (SSc) is a rare connective tissue disease characterised by immune dysfunction, vascular damage and fibrosis affecting the skin and multiple internal organs. The clinical spectrum of SSc is wide and its manifestations may lead to severe morbidity and mortality, in addition to a great impact on patients' quality of life. Due to the multifaceted clinical manifestations of SSc, its management requires a combined expertise of different medical specialists to guarantee an adequate disease control and prevent organ complications. Multi-disciplinary teams (MDT), which are composed by physicians and other specialized health professionals, represent therefore a key element for the comprehensive management of SSc patients. Moreover, MTD can improve communication and patients' empowerment while the presence of dedicated nurses can help patients to ask questions about their condition. The scope of this narrative review is to analyse the available evidences regarding the role of MDT in the management of SSc patients, and how this holistic approach may improve different disease domains and the overall prognosis. MDT regarding the cardiovascular and lung complication are the more represented in literature, given the great impact in prognosis. Nonetheless, MDT have been shown to be fundamental also in other disease domains as they can intercept early manifestations, thus stratifying patients based on the individual risks in order to personalize patients' follow-up. MDTs may also minimize the treatment delay, enabling fast-track specialist referral. On the other hand, there are few trials specifically studying MDT in SSc and several authors have highlight the lack of standardization.

4.
J Cardiovasc Med (Hagerstown) ; 22(7): 560-566, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34076604

RESUMO

AIMS: The aim of this study was to evaluate the sensitivity of right ventricular endomyocardial biopsy (EMB) in myocarditis patients with cardiac magnetic resonance (CMR) and electroanatomical mapping (EAM) showing left ventricular abnormalities. METHODS: We performed right ventricular EMB in 144 consecutive patients (66% men, age 43 ±â€Š15 years) with acute symptoms and CMR-proved diagnosis of left ventricular myocarditis. Right ventricular EMB sensitivity has been evaluated in patients with different localization and extension of abnormal substrate at both CMR and -- when performed -- EAM. Abnormal substrate was defined, respectively, by late gadolinium enhancement (LGE) and low-voltage areas (LVAs). RESULTS: Globally, right ventricular EMB sensitivity was 87.5%. EMB-negative cases had significantly smaller fragment sizes (cumulative area 2.8 ±â€Š1.7 vs. 3.8 ±â€Š1.8 mm2, P = 0.023), and lower LGE surface extension (24.7 ±â€Š14.2 vs. 38.5 ±â€Š20.2%, P = 0.006) and transmurality (32.0 ±â€Š26.1 vs. 49.3 ±â€Š22.6, P = 0.003). Right ventricular EMB sensitivity in patients with LGE involving both right ventricular and interventricular septum (IVS), isolated right ventricular or IVS, and remote left ventricular areas (n = 10, 49 and 67 cases) was 83.3, 84.4 and 90.5%, respectively (P = 0.522). Overall, 34 patients (23.6%) underwent EAM. On the basis of EAM, right ventricular EMB sensitivity was 85.3%: in detail, it was 50.0, 88.2 and 86.7% in patients with both right ventricular and IVS, isolated right ventricular/IVS and distant left ventricular involvement (n = 2, 17 and 15, respectively, P > 0.05). Sample size area was the only factor associated with right ventricular EMB sensitivity (hazard ratio = 1.6/mm2, 95% confidence interval 1.1-2.4, P = 0.013). CONCLUSION: Right ventricular EMB is still an accurate technique to confirm diagnosis in patients with CMR-proved left ventricular myocarditis. In particular, provided there is an adequate sample size, its sensitivity is comparable among patients with heterogeneous LGE or LVA localization.


Assuntos
Biópsia , Técnicas Eletrofisiológicas Cardíacas , Ventrículos do Coração , Miocardite , Adulto , Biópsia/métodos , Biópsia/estatística & dados numéricos , Meios de Contraste/farmacologia , Técnicas Eletrofisiológicas Cardíacas/métodos , Técnicas Eletrofisiológicas Cardíacas/estatística & dados numéricos , Feminino , Gadolínio/farmacologia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Humanos , Aumento da Imagem/métodos , Biópsia Guiada por Imagem/métodos , Imagem Cinética por Ressonância Magnética/métodos , Masculino , Miocardite/diagnóstico por imagem , Miocardite/patologia , Tamanho da Amostra , Sensibilidade e Especificidade
5.
JACC Cardiovasc Imaging ; 9(7): 822-832, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26897692

RESUMO

OBJECTIVES: This study sought to compare myocardial scars depicted by computed tomography (CT) with electrical features from electro-anatomic mapping (EAM), assessing the potential role of CT integration in ventricular tachycardia (VT) and radiofrequency catheter ablation (RFCA) procedures. BACKGROUND: Imaging-based characterization of VT myocardial substrate is required to plan EAM and, potentially, to guide RFCA. METHODS: Forty-two consecutive patients, 35 of whom had implantable cardioverter-defibrillator, all referred for VT RFCA, underwent pre-procedural CT including an angiographic and a 10-min delayed-enhancement scan. Segmental comparison between scars segmented from CT and low voltages (bipolar voltages <1.5 mV; unipolar voltages <8 mV), late potentials, and RF ablation points on EAM, was carried out. In a subset of 16 consecutive patients, a further point-by-point analysis was performed: a CT-derived 3-dimensional structure including heart anatomy and myocardial scars was integrated with EAM for quantitative comparison. RESULTS: CT scans identified scars in 39 patients and defined left ventricular wall involvement and mural distribution. Overall segmental concordance between CT and EAM was good (κ = 0.536) despite the presence of implantable cardioverter-defibrillator, scar etiologies, and mural distribution. CT identified segments characterized by low voltages with good sensitivity (76%), good specificity (86%), and very high negative predictive value (95%). Late potentials and RF ablation points fell on scarred segments identified from CT in 79% and 81% of cases, respectively. Point-by-point quantitative comparison revealed good correlation between the average area of scar detected at CT and at bipolar mapping (CT = 4,901 mm(2), bipolar voltages-EAM = 4,070 mm(2); R = 0.78; p < 0.0001). In this study, 70% and 84% of low-amplitude bipolar points were mapped at a maximum distance of 5 mm and 10 mm from CT-segmented scar, respectively. CONCLUSIONS: CT with delayed-enhancement provides a 3-dimensional characterization of VT scar substrate together with a detailed anatomic model of the heart. This information may offer assistance to plan EAM and RFCA procedures and is potentially suitable for EAM-imaging integration.


Assuntos
Cardiomiopatias/diagnóstico por imagem , Cicatriz/diagnóstico por imagem , Técnicas Eletrofisiológicas Cardíacas , Tomografia Computadorizada Multidetectores , Miocárdio/patologia , Taquicardia Ventricular/diagnóstico por imagem , Potenciais de Ação , Idoso , Cardiomiopatias/complicações , Cardiomiopatias/fisiopatologia , Ablação por Cateter , Cicatriz/complicações , Cicatriz/fisiopatologia , Angiografia por Tomografia Computadorizada , Meios de Contraste/administração & dosagem , Desfibriladores Implantáveis , Cardioversão Elétrica/instrumentação , Feminino , Frequência Cardíaca , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Interpretação de Imagem Radiográfica Assistida por Computador , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/cirurgia
6.
Toxicol Ind Health ; 28(4): 377-84, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21911428

RESUMO

Polysaccharides are biopolymers that play key roles as therapeutic agents. The current study examined the efficiency of a polysaccharide newly derived from a plant resource for detection of sub-acute mercury (Hg) exposure on blood characteristics of Atlantic salmon. The polysaccharide was extracted from the roots of Acanthophyllum bracteatum, and the Atlantic salmon were divided into three groups and placed in fiberglass tanks: one with no Hg as a control, one filled with 60 µg l(-1) of Hg solution, and one with 60 µg l(-1) Hg solution plus 1% weight/weight (w/w) of polysaccharide, which had been added 24 hours before the addition of Hg solution. Serum hematological and biochemical parameters were analysed. Results of the study showed that the blood factors were significantly adjusted in the group that had been exposed to the polysaccharide and Hg compared to the group that had been exposed only to Hg. The polysaccharide had an adjustment effect on lymphocytes, granulocytes, red blood cells (RBCs), Hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), protein, chlorine (Cl), sodium (Na), and glucose. It did not have a significant effect on hematocrit (Ht), mean corpuscular hemoglobin concentration (MCHC), potassium (K), and monocytes. Finally, the results confirmed that the new polysaccharide has useful effects on the host, possibly acting as a probiotic by selectively motivating the activity of some useful bacteria, which can improve the host health. This is the first report on application of this polysaccharide for the health improvement of Atlantic salmon exposed to mercury chloride.


Assuntos
Caryophyllaceae/química , Doenças dos Peixes/tratamento farmacológico , Cloreto de Mercúrio/toxicidade , Extratos Vegetais/farmacologia , Polissacarídeos/farmacologia , Salmo salar , Análise de Variância , Animais , Sangue/efeitos dos fármacos , Células Sanguíneas/citologia , Células Sanguíneas/efeitos dos fármacos , Análise Química do Sangue , Doenças dos Peixes/sangue , Doenças dos Peixes/induzido quimicamente , Contagem de Leucócitos , Fígado/química , Mercúrio/análise , Mercúrio/sangue , Raízes de Plantas/química , Substâncias Protetoras/farmacologia , Distribuição Aleatória , Água/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA