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1.
Sensors (Basel) ; 20(6)2020 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-32235780

RESUMO

According to the World Health Organization (WHO), Diabetes Mellitus (DM) is one of the most prevalent diseases in the world. It is also associated with a high mortality index. Diabetic foot is one of its main complications, and it comprises the development of plantar ulcers that could result in an amputation. Several works report that thermography is useful to detect changes in the plantar temperature, which could give rise to a higher risk of ulceration. However, the plantar temperature distribution does not follow a particular pattern in diabetic patients, thereby making it difficult to measure the changes. Thus, there is an interest in improving the success of the analysis and classification methods that help to detect abnormal changes in the plantar temperature. All this leads to the use of computer-aided systems, such as those involved in artificial intelligence (AI), which operate with highly complex data structures. This paper compares machine learning-based techniques with Deep Learning (DL) structures. We tested common structures in the mode of transfer learning, including AlexNet and GoogleNet. Moreover, we designed a new DL-structure, which is trained from scratch and is able to reach higher values in terms of accuracy and other quality measures. The main goal of this work is to analyze the use of AI and DL for the classification of diabetic foot thermograms, highlighting their advantages and limitations. To the best of our knowledge, this is the first proposal of DL networks applied to the classification of diabetic foot thermograms. The experiments are conducted over thermograms of DM and control groups. After that, a multi-level classification is performed based on a previously reported thermal change index. The high accuracy obtained shows the usefulness of AI and DL as auxiliary tools to aid during the medical diagnosis.


Assuntos
Aprendizado Profundo , Pé Diabético/classificação , Pé Diabético/diagnóstico , Termografia/métodos , Inteligência Artificial , Humanos , Aprendizado de Máquina , Máquina de Vetores de Suporte
2.
Int J Mol Sci ; 19(11)2018 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-30400174

RESUMO

Endothelial cells perform a wide variety of fundamental functions for the cardiovascular system, their proliferation and migration being strongly regulated by their intracellular calcium concentration. Hence it is extremely important to carefully measure endothelial calcium signals under different stimuli. A proposal to automate the intracellular calcium profiles extraction from fluorescence image sequences is presented. Digital image processing techniques were combined with a multi-target tracking approach supported by Kalman estimation. The system was tested with image sequences from two different stimuli. The first one was a chemical stimulus, that is, ATP, which caused small movements in the cells trajectories, thereby suggesting that the bath application of the agonist does not generate significant artifacts. The second one was a mechanical stimulus delivered by a glass microelectrode, which caused major changes in cell trajectories. The importance of the tracking block is evidenced since more accurate profiles were extracted, mainly for cells closest to the stimulated area. Two important contributions of this work are the automatic relocation of the region of interest assigned to the cells and the possibility of data extraction from big image sets in efficient and expedite way. The system may adapt to different kind of cell images and may allow the extraction of other useful features.


Assuntos
Cálcio/metabolismo , Células Endoteliais/metabolismo , Processamento de Imagem Assistida por Computador , Espaço Intracelular/metabolismo , Trifosfato de Adenosina/metabolismo , Algoritmos , Animais , Automação , Fluorescência , Masculino , Ratos Wistar
3.
Sensors (Basel) ; 13(8): 10561-83, 2013 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-23948873

RESUMO

This paper presents a project on the development of a cursor control emulating the typical operations of a computer-mouse, using gyroscope and eye-blinking electromyographic signals which are obtained through a commercial 16-electrode wireless headset, recently released by Emotiv. The cursor position is controlled using information from a gyroscope included in the headset. The clicks are generated through the user's blinking with an adequate detection procedure based on the spectral-like technique called Empirical Mode Decomposition (EMD). EMD is proposed as a simple and quick computational tool, yet effective, aimed to artifact reduction from head movements as well as a method to detect blinking signals for mouse control. Kalman filter is used as state estimator for mouse position control and jitter removal. The detection rate obtained in average was 94.9%. Experimental setup and some obtained results are presented.


Assuntos
Acelerometria/instrumentação , Piscadela/fisiologia , Interfaces Cérebro-Computador , Encéfalo/fisiologia , Periféricos de Computador , Eletroencefalografia/instrumentação , Movimentos Oculares/fisiologia , Algoritmos , Desenho de Equipamento , Análise de Falha de Equipamento
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