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1.
Sensors (Basel) ; 23(24)2023 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-38139724

RESUMO

Monitoring heart electrical activity is an effective way of detecting existing and developing conditions. This is usually performed as a non-invasive test using a network of up to 12 sensors (electrodes) on the chest and limbs to create an electrocardiogram (ECG). By visually observing these readings, experienced professionals can make accurate diagnoses and, if needed, request further testing. However, the training and experience needed to make accurate diagnoses are significant. This work explores the potential of recurrent neural networks for anomaly detection in ECG readings. Furthermore, to attain the best possible performance for these networks, training parameters, and network architectures are optimized using a modified version of the well-established particle swarm optimization algorithm. The performance of the optimized models is compared to models created by other contemporary optimizers, and the results show significant potential for real-world applications. Further analyses are carried out on the best-performing models to determine feature importance.


Assuntos
Algoritmos , Redes Neurais de Computação , Eletrocardiografia/métodos
3.
BMC Pregnancy Childbirth ; 23(1): 20, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36631859

RESUMO

BACKGROUND: Congenital Heart Disease represents the most frequent fetal malformation. The lack of prenatal identification of congenital heart defects can have adverse consequences for the neonate, while a correct prenatal diagnosis of specific cardiac anomalies improves neonatal care neurologic and surgery outcomes. Sonographers perform prenatal diagnosis manually during the first or second-trimester scan, but the reported detection rates are low. This project's primary objective is to develop an Intelligent Decision Support System that uses two-dimensional video files of cardiac sweeps obtained during the standard first-trimester fetal echocardiography (FE) to signal the presence/absence of previously learned key features. METHODS: The cross-sectional study will be divided into a training part of the machine learning approaches and the testing phase on previously unseen frames and eventually on actual video scans. Pregnant women in their 12-13 + 6 weeks of gestation admitted for routine first-trimester anomaly scan will be consecutively included in a two-year study, depending on the availability of the experienced sonographers in early fetal cardiac imaging involved in this research. The Data Science / IT department (DSIT) will process the key planes identified by the sonographers in the two- dimensional heart cine loop sweeps: four-chamber view, left and right ventricular outflow tracts, three vessels, and trachea view. The frames will be grouped into the classes representing the plane views, and then different state-of-the- art deep-learning (DL) pre-trained algorithms will be tested on the data set. The sonographers will validate all the intermediary findings at the frame level and the meaningfulness of the video labeling. DISCUSSION: FE is feasible and efficient during the first trimester. Still, the continuous training process is impaired by the lack of specialists or their limited availability. Therefore, in our study design, the sonographer benefits from a second opinion provided by the developed software, which may be very helpful, especially if a more experienced colleague is unavailable. In addition, the software may be implemented on the ultrasound device so that the process could take place during the live examination. TRIAL REGISTRATION: The study is registered under the name "Learning deep architectures for the Interpretation of Fetal Echocardiography (LIFE)", project number 408PED/2020, project code PN-III-P2-2.1-PED-2019. TRIAL REGISTRATION: ClinicalTrials.gov , unique identifying number NCT05090306, date of registration 30.10.2020.


Assuntos
Cardiopatias Congênitas , Ultrassonografia Pré-Natal , Recém-Nascido , Gravidez , Feminino , Humanos , Primeiro Trimestre da Gravidez , Estudos Transversais , Ultrassonografia Pré-Natal/métodos , Cardiopatias Congênitas/diagnóstico por imagem , Ecocardiografia , Coração Fetal/diagnóstico por imagem
4.
BMJ Open ; 11(9): e047188, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34493509

RESUMO

INTRODUCTION: Over the last decades, a large body of literature has shown that intrapartum clinical digital pelvic estimations of fetal head position, station and progression in the pelvic canal are less accurate, compared with ultrasound (US) scan. Given the increasing evidence regarding the advantages of using US to evaluate the mechanism of labour, our study protocol aims to develop sonopartograms for fetal cephalic presentations. They will allow for a more objective evaluation of labour progression than the traditional labour monitoring, which could enable more rapid decisions regarding the mode of delivery. METHODS/ANALYSIS: This is a prospective observational study performed in three university hospitals, with an unselected population of women admitted in labour at term. Both clinical and US evaluations will be performed assessing fetal head position, descent and rotation. Specific US parameters regarding fetal head position, progression and rotation will be recorded to develop nomograms in a similar way that partograms were developed. The primary outcome is to develop nomograms for the longitudinal US assessment of labour in unselected nulliparous and multiparous women with fetal cephalic presentation. The secondary aims are to assess the sonopartogram differences in occiput anterior and posterior deliveries, to compare the labour trend from our research with the classic and other recent partogram models and to investigate the capability of the US labour monitoring to predict the outcome of spontaneous vaginal delivery. ETHICS AND DISSEMINATION: All protocols and the informed consent form comply with the Ministry of Health and the professional society ethics guidelines. University ethics committees approved the study protocol. The trial results will be published in peer-reviewed journals and at the conference presentations. The study will be implemented and reported in line with the Strengthening the Reporting of Observational Studies in Epidemiology statement. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT02326077).


Assuntos
Feto , Apresentação no Trabalho de Parto , Parto Obstétrico , Feminino , Feto/diagnóstico por imagem , Humanos , Estudos Observacionais como Assunto , Gravidez , Ultrassonografia , Ultrassonografia Pré-Natal
5.
PLoS One ; 15(7): e0236401, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32692779

RESUMO

Medical data are often tricky to get mined for patterns even by the generally demonstrated successful modern methodologies of deep learning. This paper puts forward such a medical classification task, where patient registers of two of the categories are sometimes hard to be distinguished because of samples showing characteristics of both labels in turn in several repetitions of the screening procedure. To this end, the current research appoints a pre-processing clustering step (through self-organizing maps) to group the data based on shape similarity and relabel it accordingly. Subsequently, a deep learning approach (a tandem of convolutional and long short-term memory networks) performs the training classification phase on the 'cleaned' samples. The dual methodology was applied for the computational diagnosis of electrooculography tests within spino-cerebral ataxia of type 2. The accuracy obtained for the discrimination into three classes was of 78.24%. The improvement that this duo brings over the deep learner alone does not stem from significantly higher accuracy results when the performance is considered for all classes. The major finding of this combination is that half of the presymptomatic cases were correctly found, in opposition to the single deep model, where this category was sacrificed by the learner in favor of a good accuracy overall. A high accuracy in general is desirable for any medical task, however the correct identification of cases before the symptoms become evident is more important.


Assuntos
Aprendizado Profundo , Eletroculografia , Aprendizado de Máquina não Supervisionado , Algoritmos , Análise por Conglomerados , Bases de Dados como Assunto , Humanos , Redes Neurais de Computação , Estimulação Luminosa , Movimentos Sacádicos/fisiologia , Fatores de Tempo
6.
Sensors (Basel) ; 20(11)2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32471077

RESUMO

Application of deep learning (DL) to the field of healthcare is aiding clinicians to make an accurate diagnosis. DL provides reliable results for image processing and sensor interpretation problems most of the time. However, model uncertainty should also be thoroughly quantified. This paper therefore addresses the employment of Monte Carlo dropout within the DL structure to automatically discriminate presymptomatic signs of spinocerebellar ataxia type 2 in saccadic samples obtained from electrooculograms. The current work goes beyond the common incorporation of this special type of dropout into deep neural networks and uses the uncertainty derived from the validation samples to construct a decision tree at the register level of the patients. The decision tree built from the uncertainty estimates obtained a classification accuracy of 81.18% in automatically discriminating control, presymptomatic and sick classes. This paper proposes a novel method to address both uncertainty quantification and explainability to develop reliable healthcare support systems.


Assuntos
Eletroculografia , Método de Monte Carlo , Redes Neurais de Computação , Ataxias Espinocerebelares , Árvores de Decisões , Humanos , Processamento de Imagem Assistida por Computador , Ataxias Espinocerebelares/diagnóstico
7.
PLoS One ; 14(10): e0223593, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31600306

RESUMO

Stock price prediction is a popular yet challenging task and deep learning provides the means to conduct the mining for the different patterns that trigger its dynamic movement. In this paper, the task is to predict the close price for 25 companies enlisted at the Bucharest Stock Exchange, from a novel data set introduced herein. Towards this scope, two traditional deep learning architectures are designed in comparison: a long short-memory network and a temporal convolutional neural model. Based on their predictions, a trading strategy, whose decision to buy or sell depends on two different thresholds, is proposed. A hill climbing approach selects the optimal values for these parameters. The prediction of the two deep learning representatives used in the subsequent trading strategy leads to distinct facets of gain.


Assuntos
Comércio , Simulação por Computador , Aprendizado Profundo , Heurística , Investimentos em Saúde/economia , Algoritmos , Redes Neurais de Computação , Reprodutibilidade dos Testes , Romênia , Fatores de Tempo
8.
Rom J Morphol Embryol ; 60(3): 841-846, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31912094

RESUMO

We analyzed 82 patients with colorectal cancer (CRC) [75 patients with mucinous adenocarcinoma (ADK) and seven patients with "signet ring cell" ADK] using multi-cytokeratin (CK) AE1∕AE3 immunohistochemical assay. In order to determine the mucinous nature of some of the lymph node metastases of the mucinous colorectal ADKs studied, Periodic Acid Schiff-Alcian Blue (PAS-AB) histochemical staining was used. The counting results were systematized in the following ranges: 0 budding areas; between 1-4 budding areas; between 5-9 budding areas; and =10 tumor budding (TB) areas. The statistical analysis was performed using the Student's t-test. More than half of the cases of mucinous ADK revealed an increased intensity of TB, whereas in the case of "signet ring cell" ADK, an average intensity of this phenomenon. Mucinous ADKs, which were pT3 staged, showed an increased intensity of TB, and those in pT2 stage demonstrated, in the vast majority of cases, the absence of TB. There was a predominance of TB intensity in the absence of vascular-lymphatic invasion. Our study shows the existence of a concordance between tumor progression, the histological type of CRC, vascular-lymphatic invasion and the phenomenon of TB.


Assuntos
Neoplasias Colorretais/imunologia , Imuno-Histoquímica/métodos , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Prognóstico
9.
Comput Biol Med ; 41(4): 238-46, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21419402

RESUMO

This paper presents an automatic tool capable to learn from a patients data set with 24 medical indicators characterizing each sample and to subsequently use the acquired knowledge to differentiate between five degrees of liver fibrosis. The indicators represent clinical observations and the liver stiffness provided by the new, non-invasive procedure of Fibroscan. The proposed technique combines a hill climbing algorithm that selects subsets of important attributes for an accurate classification and a core represented by a cooperative coevolutionary classifier that builds rules for establishing the diagnosis for every new patient. The results of the novel method proved to be superior as compared to the ones obtained by other important classification techniques from the literature. Additionally, the proposed methodology extracts a set of the most meaningful attributes from the available ones.


Assuntos
Algoritmos , Diagnóstico por Computador/métodos , Cirrose Hepática/diagnóstico , Design de Software , Humanos
10.
Artif Intell Med ; 51(1): 53-65, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20675106

RESUMO

OBJECTIVE: Hepatic fibrosis, the principal pointer to the development of a liver disease within chronic hepatitis C, can be measured through several stages. The correct evaluation of its degree, based on recent different non-invasive procedures, is of current major concern. The latest methodology for assessing it is the Fibroscan and the effect of its employment is impressive. However, the complex interaction between its stiffness indicator and the other biochemical and clinical examinations towards a respective degree of liver fibrosis is hard to be manually discovered. In this respect, the novel, well-performing evolutionary-powered support vector machines are proposed towards an automated learning of the relationship between medical attributes and fibrosis levels. The traditional support vector machines have been an often choice for addressing hepatic fibrosis, while the evolutionary option has been validated on many real-world tasks and proven flexibility and good performance. METHODS AND MATERIALS: The evolutionary approach is simple and direct, resulting from the hybridization of the learning component within support vector machines and the optimization engine of evolutionary algorithms. It discovers the optimal coefficients of surfaces that separate instances of distinct classes. Apart from a detached manner of establishing the fibrosis degree for new cases, a resulting formula also offers insight upon the correspondence between the medical factors and the respective outcome. What is more, a feature selection genetic algorithm can be further embedded into the method structure, in order to dynamically concentrate search only on the most relevant attributes. The data set refers 722 patients with chronic hepatitis C infection and 24 indicators. The five possible degrees of fibrosis range from F0 (no fibrosis) to F4 (cirrhosis). RESULTS: Since the standard support vector machines are among the most frequently used methods in recent artificial intelligence studies for hepatic fibrosis staging, the evolutionary method is viewed in comparison to the traditional one. The multifaceted discrimination into all five degrees of fibrosis and the slightly less difficult common separation into solely three related stages are both investigated. The resulting performance proves the superiority over the standard support vector classification and the attained formula is helpful in providing an immediate calculation of the liver stage for new cases, while establishing the presence/absence and comprehending the weight of each medical factor with respect to a certain fibrosis level. CONCLUSION: The use of the evolutionary technique for fibrosis degree prediction triggers simplicity and offers a direct expression of the influence of dynamically selected indicators on the corresponding stage. Perhaps most importantly, it significantly surpasses the classical support vector machines, which are both widely used and technically sound. All these therefore confirm the promise of the new methodology towards a dependable support within the medical decision-making.


Assuntos
Inteligência Artificial , Técnicas de Imagem por Elasticidade/classificação , Hepatite C Crônica/complicações , Cirrose Hepática/diagnóstico por imagem , Fígado/diagnóstico por imagem , Algoritmos , Automação Laboratorial , Biópsia , Feminino , Humanos , Fígado/virologia , Cirrose Hepática/classificação , Cirrose Hepática/virologia , Masculino , Modelos Biológicos , Reconhecimento Automatizado de Padrão , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
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