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Analysis of the effects of low-level laser therapy on muscle fatigue of the biceps brachii muscle of healthy individuals and spastic individuals
摘要： Background: Muscular fatigue is caused by biochemical alterations that modify the mechanics of muscle contraction, resulting in negative changes in the performance of the contraction. Several resources are studied to mitigate this situation among which we can cite low-level laser therapy (LLLT). The effects of LLLT are being studied in healthy subjects with fibromyalgia and who are athletes, and currently the studies are being performed in spastic muscles with poststroke individuals. The aim will be to evaluate the effects of LLLT on the fatigue of the biceps brachii muscle of healthy individuals and individuals with spastic hemiparesis. Methods: A cross-sectional, comparative, randomized, placebo, double-blind clinical trial will be divided into 2 phases: phase I shall consist of 30 healthy subjects and phase II of 30 poststroke individuals. The study will consist of 3 groups (control group, placebo group, and LLLT group), and all individuals will pass through all groups, following the randomization criteria. The protocol consists of the application of LLLT in the biceps brachii muscle on the dominant side in healthy individuals and in the hemiparetic side of poststroke individuals, and, subsequently, 3 maximal isometric voluntary contractions (MIVCs) will be performed for 50 seconds in the dynamometer, with an interval of 50 seconds between them. Pain intensity will be evaluated by means of the visual analog scale, and the myoelectric activity by means of surface electromyography associated with the evaluation of muscular strength by means of the dynamometer. The local temperature will be evaluated by infrared thermography and blood lactate concentration through the lactimeter, which will be measured at 4 different times, before the application of the laser (basal), and 3, 15, and 25 minutes after the MIVC.
关键词： stroke,spasticity,infrared thermography,muscular fatigue,photobiomodulation
更新于2025-09-11 14:15:04
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Local sparseness and image fusion for defect inspection in eddy current pulsed thermography
摘要： Defect feature extraction and analysis based on eddy current pulsed thermography (ECPT) technique is a research focus in non-destructive testing area. In this paper, a new feature extraction method based on thermography is proposed to enhance quantitative defect information. The proposed method included entropy-based image selection, local (element-wise) sparse and low rank decomposition (LSLD) and image fusion can increase the contrast of defect area and background and extract more useful defect features than other two common feature extraction algorithms in ECPT. The experiments including comparison results are provided to demonstrate the capabilities and benefits of the proposed algorithm. More meaningful defect information of the experimental specimens is reserved from raw ECPT data and background is suppressed severely compared with other feature extraction algorithms.
关键词： local sparse,eddy current,image fusion,non-destructive evaluation,thermography
更新于2025-09-11 14:15:04
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Detectability of Delamination in Concrete Structure Using Active Infrared Thermography in Terms of Signal-to-Noise Ratio
摘要： Detecting subsurface delamination is a dif?cult and vital task to maintain the durability and serviceability of concrete structure for its whole life cycle. The aim of this work was to obtain better knowledge of the effect of depth, heating time, and rebar on the detectability capacity of delamination. Experimental tests were carried out on a concrete specimen in the laboratory using Long Pulsed Thermography (LPT). Six halogen lamps and a long wavelength infrared camera with a focal plane array of 640 × 480 pixels were used as the heat source and infrared detector, respectively. The study focused on the embedded imitation delaminations with the size of 10 cm × 10 cm × 1 cm, located at depths varying from 1 to 8 cm. The signal-to-noise ratio (SNR) was applied as a criterion to assess the detectability of delamination. The results of this study indicate that as the provided heating time climbed, the SNR increased, and the defect could be identi?ed more clearly. On the other hand, when using the same heating regime, a shallow delamination displayed a higher SNR than a deeper one. The moderate fall of the SNR in the case of imitating defect located below reinforced steel was also observed. The absolute contrast was monitored to determine the observation time, and the nondimensional prefactor k was empirically proposed to predict the depth of delamination. The mean absolute percentage error (MAPE) was used to quantitatively evaluate the difference between forecasted and real depth, which evaluation con?rmed the high reliability of the estimated value of the prefactor k.
关键词： signal-to-noise ratio (SNR),nondestructive technique (NDT),reinforced concrete,infrared thermography,long pulsed thermography,delamination
更新于2025-09-10 09:29:36
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Multi-Modality Imaging (Applications and Computational Techniques) || Infrared Thermography
摘要： Infrared thermography (also infrared imaging or thermal imaging) is a new remote, non-contact and non-invasive diagnostic and monitoring technique with increasing relevance in a wide range of medical ?elds. This is mainly due to the several advantages of this technology. Thermal imaging is a passive technique which detects the radiation naturally emitted from an object, in this case the human skin, and does not use any harmful radiation. Thus, infrared thermography (IRT) is suitable for prolonged and repeated use. In the last decades, new medical applications for thermal imaging have arisen. These techniques have been successfully used in the diagnosis of several pathologies, including breast cancer, rheumatic diseases, dry eye syndrome, vascular diseases, etc. Infrared thermography has also demonstrated its potential in the monitoring of several vital signs, including temperature, respiratory rate, heart rate, and blood perfusion. Recently, there has been new advance in 3D infrared imaging. A three-dimensional thermal signature may provide several advantages in the detection and monitoring of the course of several pathologies including arthritis, thyroid dysfunctions, breast cancer, sports lesions, and diabetic foot. The current chapter focuses on advances in the area of medical IRT. First, it reviews the basics of IRT and essential theoretical background. Second, some medical applications and corresponding methods are described in detail. Third, it gives an overview on the recent advances on “3D Infrared Thermography”.
关键词： 3D infrared thermography,Infrared thermography,Diagnostic,Monitoring,Medical applications
更新于2025-09-10 09:29:36
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Development and validation of an algorithm to predict the treatment modality of burn wounds using thermographic scans: Prospective cohort study
摘要： Background The clinical evaluation of a burn wound alone may not be adequate to predict the severity of the injury nor to guide clinical decision making. Infrared thermography provides information about soft tissue viability and has previously been used to assess burn depth. The objective of this study was to determine if temperature differences in burns assessed by infrared thermography could be used predict the treatment modality of either healing by re-epithelization, requiring skin grafts, or requiring amputations, and to validate the clinical predication algorithm in an independent cohort. Methods and findings Temperature difference (ΔT) between injured and healthy skin were recorded within the first three days after injury in previously healthy burn patients. After discharge, the treatment modality was categorized as re-epithelization, skin graft or amputation. Potential confounding factors were assessed through multiple linear regression models, and a prediction algorithm based on the ΔT was developed using a predictive model using a recursive partitioning Random Forest machine learning algorithm. Finally, the prediction accuracy of the algorithm was compared in the development cohort and an independent validation cohort. Significant differences were found in the ΔT between treatment modality groups. The developed algorithm correctly predicts into which treatment category the patient will fall with 85.35% accuracy. Agreement between predicted and actual treatment for both cohorts was weighted kappa 90%. Conclusion Infrared thermograms obtained at first contact with a wounded patient can be used to accurately predict the definitive treatment modality for burn patients. This method can be used to rationalize treatment and streamline early wound closure.
关键词： treatment modality,prediction algorithm,burn wounds,Random Forest machine learning,infrared thermography
更新于2025-09-10 09:29:36
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Handbook of Advanced Non-Destructive Evaluation || Induction Thermography of Surface Defects
摘要： A survey on theory, characteristic quantities, and the experimental technique of induction thermography is given. Induction thermography is used for surface defect detection in forged parts of ferromagnetic steel at typical frequencies of 100–300 kHz. Values for the detection limits for various types of cracks and approaches to determine crack depths are given. The sensitivity for crack detection is comparable to magnetic particle inspection. A hidden defect in ferritic steel with a coverage of 140 μm was detected by lowering the induction frequency down to 1500 Hz. Cracks in silicon solar cells were detected. Defects of ?bers were detected in carbon ?ber reinforced polymer (CFRP). Inductive excitation is complementary to ?ash excitation. Crack detection in railway components like rails and wheels was shown. In rails, a larger defect could be detected from a test car moving at a speed of up to 15 km/h. A fully automated demonstrator for wheel testing was built up, which can detect surface defects in railway wheels with sensitivity comparable to magnetic particle testing. Standardization of thermography has gained progress in the last years and led to ?rst standards on active thermography and induction thermography.
关键词： surface defect detection,induction thermography,crack detection,carbon fiber reinforced polymer,railway component testing,ferromagnetic steel
更新于2025-09-10 09:29:36
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Application of IR Thermography with Thermal Diffusivity Analysis for Detection of Plies Displacement in CFRP Composites
摘要： This paper presents an efficient nondestructive testing (NDT) method for detection of plies displacement in carbon fiber reinforced plastic (CFRP) composites using the active thermography technique. To assess the capability of the proposed technique for detection of plies displacement, the CFRP composite specimens with simulated fault were designed and manufactured. The IR thermography measurements were conducted using two-sided experimental arrangement. From recorded sequences of thermal images, the temperature variations versus time plots were extracted to obtain the maximum thermal contrasts. For quantitative interpretation of the results, the thermal diffusivity values for each composite material were determined and related to the fiber volume fraction. The experimental results showed that the thermal diffusivity increases with an increase of fiber volume fraction; further, the values of thermal diffusivity are specimen thickness dependent. The obtained values of thermal diffusivity varied from 1.5 3 1027 m2/s (for 3.2 mm composite with 8.5 vol.% carbon fiber) to 2.6 3 1027 m2/s (for 7.7 mm composite with 34.1 vol.% carbon fiber). On the basis of these results, it was concluded that the active thermography combined with thermal diffusivity analysis can be considered as a reliable NDT technique for detection of plies displacement in CFRP composites.
关键词： thermal contrast,active thermography,thermal diffusivity,CFRP composites,plies displacement
更新于2025-09-10 09:29:36
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High velocity infrared thermography and numerical trajectories of solid particles in compressible gas flow
摘要： The use of High Velocity Infrared Thermography as a valuable alternative to other existing techniques for the visualisation and tracking of solid particles transported by a gas jet has been assessed by considering different situations in terms of problem characteristic numbers (jet Reynolds and Mach numbers and Particle Stokes and gravitational Froude numbers). Particles paths have also been calculated by means of a hybrid Eulerian-Lagrangian technique under the intent to cross-validate the two (experimental and numerical) approaches. The results indicate that such a strategy is robust and sufficiently flexible to be used in relatively wide regions of the space of parameters. Experiments have clearly demonstrated that thermography can properly capture particle dynamics with a level of detail comparable to that provided by simulations. Computations have proved to be valuable on their own by allowing the explorations of regions of the parameters space otherwise out of reach. Different tests have been conducted considering both isolated particles and “swarms”. We show that the observed dynamics are induced by the delicate interplay of different effects, including inertial, gravitational and eventually “lift” contributions produced by a non-perfect horizontal orientation of the jet or other uncertainties (such as those due to a non mono-sized set of particles).
关键词： Multiphase Flow,solid particles,jet,hybrid Eulerian-Lagrangian approach,High Velocity Infrared Thermography
更新于2025-09-10 09:29:36
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Digitised Frequency Modulated Thermal Wave Imaging for Non-destructive Testing and Evaluation of Glass Fibre Reinforced Polymers
摘要： The active thermal non-destructive testing and evaluation techniques have gained wide acceptance in health monitoring of various solids materials such as metals, composites and semiconductors. The most popular active infrared thermographic methods for non-destructive testing and evaluation applications are pulse based thermography and lock-in thermography techniques. But the usage of these techniques is limited due to their inherent limitations. To overcome the limitations of the existing approaches, the present work demonstrates the effectiveness of digitized frequency modulated thermal wave imaging technique for detection of different shaped defects in a glass fibre reinforced polymer specimen. Further, the usage of post-processing scheme facilitates defect detection with high resolution and also preserves the shape of defects.
关键词： Non-destructive Testing,Thermal waves,Thermal Wave Imaging,Active Infrared Thermography
更新于2025-09-10 09:29:36
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A Quantitative Comparison Among Different Algorithms for Defects Detection on Aluminum with the Pulsed Thermography Technique
摘要： Pulsed thermography is commonly used as a non-destructive technique for evaluating defects within materials and components. In the last few years, many algorithms have been developed with the aim to detect defects and different methods have been used for detecting their size and depth. However, only few works in the literature reported a comparison among the different algorithms in terms of the number of detected defects, the time spent in testing and analysis, and the quantitative evaluation of size and depth. In this work, starting from a pulsed thermographic test carried out on an aluminum specimen with twenty ?at bottom holes of known nominal size and depth, different algorithms have been used with the aim to obtain a comparison among them in terms of signal to background contrast (SBC) and number of detected defects by analyzing different time intervals. Moreover, the correlation between SBC and the aspect ratio of the defects has been investigated. The algorithms used have been: Pulsed Phase Thermography (PPT), Slope, Correlation Coef?cient (R2), Thermal Signal Reconstruction (TSR) and Principal Component Thermography (PCT). The results showed the advantages, disadvantages, and sensitivity of the various thermographic algorithms.
关键词： non-destructive testing,quantitative analysis,pulsed thermography,aluminum
更新于2025-09-10 09:29:36