Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Therm Biol ; 91: 102613, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32716863

RESUMO

The aim of the study was to evaluate skin temperature of the soles of the feet before and after a provoked asymmetrical running. Seventeen recreational male runners performed two 15 min running tests in the same session. In the first test, participants performed running without modifying their running technique (control condition). In the second running test, they repeated the same protocol using an ankle weight of 1.5 kg in the non-dominant ankle (asymmetrical condition). Rate of perceive exertion, heart rate and spatio-temporal parameters were measured during the running tests. Skin temperature was measured with an infrared camera before and after each condition. Generally, comparing both lower limbs, non-preferred limb (with the ankle weight) had lower contact time (p < 0.001 and ES > 0.8), higher stride length (p < 0.05 and ES > 0.3) and higher stride frequency in asymmetrical condition (p < 0.01 and ES > 0.4). However, no differences were observed on skin temperature between both feet in the two conditions in any of the regions of interest assessed (p > 0.05). Although the asymmetry generation model used provoked technical asymmetries in spatio-temporal parameters during running, no thermal asymmetries were observed between preferred and non-preferred sole of the foot. These results suggested the lower importance of mechanical than physiological mechanisms on skin temperature during running.


Assuntos
Pé/fisiologia , Corrida/fisiologia , Temperatura Cutânea , Adulto , Tornozelo/fisiologia , Fenômenos Biomecânicos , Peso Corporal , Humanos , Masculino
3.
Sensors (Basel) ; 18(1)2018 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-29324692

RESUMO

Dynamic laser speckle (DLS) is used as a reliable sensor of activity for all types of materials. Traditional applications are based on high-rate captures (usually greater than 10 frames-per-second, fps). Even for drying processes in conservation treatments, where there is a high level of activity in the first moments after the application and slower activity after some minutes or hours, the process is based on the acquisition of images at a time rate that is the same in moments of high and low activity. In this work, we present an alternative approach to track the drying process of protective layers and other painting conservation processes that take a long time to reduce their levels of activity. We illuminate, using three different wavelength lasers, a temporary protector (cyclododecane) and a varnish, and monitor them using a low fps rate during long-term drying. The results are compared to the traditional method. This work also presents a monitoring method that uses portable equipment. The results present the feasibility of using the portable device and show the improved sensitivity of the dynamic laser speckle when sensing the long-term process for drying cyclododecane and varnish in conservation.

4.
J Biomed Opt ; 22(4): 45010, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28444121

RESUMO

Dynamic laser speckle phenomenon allows a contactless and nondestructive way to monitor biological changes that are quantified by second-order statistics applied in the images in time using a secondary matrix known as time history of the speckle pattern (THSP). To avoid being time consuming, the traditional way to build the THSP restricts the data to a line or column. Our hypothesis is that the spatial restriction of the information could compromise the results, particularly when undesirable and unexpected optical inhomogeneities occur, such as in cell culture media. It tested a spatial random approach to collect the points to form a THSP. Cells in a culture medium and in drying paint, representing homogeneous samples in different levels, were tested, and a comparison with the traditional method was carried out. An alternative random selection based on a Gaussian distribution around a desired position was also presented. The results showed that the traditional protocol presented higher variation than the outcomes using the random method. The higher the inhomogeneity of the activity map, the higher the efficiency of the proposed method using random points. The Gaussian distribution proved to be useful when there was a well-defined area to monitor.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Lasers , Algoritmos , Animais , Gatos , Coffea , Meios de Cultura , Aumento da Imagem/métodos , Luz , Camundongos , Neoplasias/diagnóstico por imagem , Distribuição Normal , Reconhecimento Automatizado de Padrão , Células RAW 264.7 , Sementes , Propriedades de Superfície
5.
Eur J Pediatr ; 174(4): 493-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25241828

RESUMO

UNLABELLED: Musculoskeletal injuries are a leading cause of paediatric injuries and emergency department visits in Western countries. Diagnosis usually involves radiography, but this exposes children without fractures to unnecessary ionising radiation. We explored whether infrared thermography could provide a viable alternative in trauma cases. We compared radiography and thermal images of 133 children who had been diagnosed with a trauma injury in the emergency unit of a Spanish hospital. As well as the thermal variables in the literature, we introduced a new quantifier variable, the size of the lesion. Decision tree models were built to assess the technique's accuracy in diagnosing whether a bone had been fractured or not. Infrared thermography had a sensitivity of 0.91, a specificity of 0.88 and a negative predictive value of 0.95. The new lesion size variable introduced appeared to be of main importance to the discriminatory power of the method. CONCLUSION: The high negative predictive value of infrared thermography suggests that it is a promising method for ruling out fractures.


Assuntos
Fraturas Ósseas/diagnóstico , Termografia/métodos , Adolescente , Criança , Pré-Escolar , Serviço Hospitalar de Emergência , Feminino , Humanos , Lactente , Raios Infravermelhos , Masculino , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Espanha
6.
J Biomed Opt ; 19(5): 057008, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24828071

RESUMO

This work presents the development of a protocol based on the dynamic laser speckle designed to monitor the reaction of cancer cells of line MEL-RC08 to the application of the drug Colcemid in two different concentrations: 0.2 and 0.4 µg/mL. The protocol was designed using the forward scattering approach with an He-Ne laser of 632.8 nm illuminating the samples, a control, and two variations of Colcemid, being monitored along 8 h. The data were analyzed numerically in the time and in the frequency domain, and the results presented the ability of the technique to monitor the action of the drug, particularly Colcemid (0.4 µg/mL).


Assuntos
Demecolcina/farmacologia , Diagnóstico por Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Lasers , Melanoma/química , Análise de Variância , Antineoplásicos Fitogênicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Melanoma/metabolismo
7.
J Biomed Opt ; 17(4): 048002, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22559698

RESUMO

The introduction of new techniques for endodontic procedures requires the analysis of the biomechanical behavior of dental structures. Digital speckle shearing pattern interferometry (DSSPI) is a nondestructive optical measuring technique that allows one to directly quantify deformations in teeth that are subjected to stress. DSSPI technique was applied to measure small deformations caused by flexion in different types of teeth. The test was carried out both before and after endodontic treatment with the ProTaper method in order to evaluate the variation of dental elasticity, taking into the account the type of tooth and the endodontic treatment. The results obtained show that dental elasticity, established by means of the apparent Young's modulus, before and after the endodontic treatment, differs between incisors and premolars. The endodontic process does not affect dental elasticity (p>0.7). Specifically, 57.1% of central incisors and 56.3% of second premolars slightly increase their elasticity after the endodontic process. In turn, 42.9% of central incisors and 43.7% of second premolars slightly decrease elasticity. The endodontic treatment especially affects the "neutral fibre"; therefore, there is little influence on elasticity by flexion. However, after finishing the process, the channel was restored with material, which can slightly increase tooth elasticity in some cases.


Assuntos
Dente Pré-Molar/cirurgia , Módulo de Elasticidade/fisiologia , Endodontia/métodos , Incisivo/cirurgia , Interferometria/métodos , Análise de Variância , Dente Pré-Molar/fisiologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Incisivo/fisiologia , Análise de Regressão
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...