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19 pages, 1889 KiB  
Article
Infrared Thermographic Signal Analysis of Bioactive Edible Oils Using CNNs for Quality Assessment
by Danilo Pratticò and Filippo Laganà
Signals 2025, 6(3), 38; https://doi.org/10.3390/signals6030038 (registering DOI) - 1 Aug 2025
Abstract
Nutrition plays a fundamental role in promoting health and preventing chronic diseases, with bioactive food components offering a therapeutic potential in biomedical applications. Among these, edible oils are recognised for their functional properties, which contribute to disease prevention and metabolic regulation. The proposed [...] Read more.
Nutrition plays a fundamental role in promoting health and preventing chronic diseases, with bioactive food components offering a therapeutic potential in biomedical applications. Among these, edible oils are recognised for their functional properties, which contribute to disease prevention and metabolic regulation. The proposed study aims to evaluate the quality of four bioactive oils (olive oil, sunflower oil, tomato seed oil, and pumpkin seed oil) by analysing their thermal behaviour through infrared (IR) imaging. The study designed a customised electronic system to acquire thermographic signals under controlled temperature and humidity conditions. The acquisition system was used to extract thermal data. Analysis of the acquired thermal signals revealed characteristic heat absorption profiles used to infer differences in oil properties related to stability and degradation potential. A hybrid deep learning model that integrates Convolutional Neural Networks (CNNs) with Long Short-Term Memory (LSTM) units was used to classify and differentiate the oils based on stability, thermal reactivity, and potential health benefits. A signal analysis showed that the AI-based method improves both the accuracy (achieving an F1-score of 93.66%) and the repeatability of quality assessments, providing a non-invasive and intelligent framework for the validation and traceability of nutritional compounds. Full article
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18 pages, 4279 KiB  
Article
Chemophotothermal Combined Therapy with 5-Fluorouracil and Branched Gold Nanoshell Hyperthermia Induced a Reduction in Tumor Size in a Xenograft Colon Cancer Model
by Sarah Eliuth Ochoa-Hugo, Karla Valdivia-Aviña, Yanet Karina Gutiérrez-Mercado, Alejandro Arturo Canales-Aguirre, Verónica Chaparro-Huerta, Adriana Aguilar-Lemarroy, Luis Felipe Jave-Suárez, Mario Eduardo Cano-González, Antonio Topete, Andrea Molina-Pineda and Rodolfo Hernández-Gutiérrez
Pharmaceutics 2025, 17(8), 988; https://doi.org/10.3390/pharmaceutics17080988 (registering DOI) - 30 Jul 2025
Abstract
Background/Objectives: The heterogeneity of cancer disease and the frequent ineffectiveness and resistance observed with currently available treatments highlight the importance of developing new antitumor therapies. The properties of gold nanoparticles, such as their photon-energy heating, are attractive for oncology therapy; this can [...] Read more.
Background/Objectives: The heterogeneity of cancer disease and the frequent ineffectiveness and resistance observed with currently available treatments highlight the importance of developing new antitumor therapies. The properties of gold nanoparticles, such as their photon-energy heating, are attractive for oncology therapy; this can be effective and localized. The combination of chemotherapy and hyperthermia is promising. Our aim was to evaluate the combination therapy of photon hyperthermia with 5-fluorouracil (5-FU) both in vitro and in vivo. Methods: This study evaluated the antitumor efficacy of a combined chemo-photothermal therapy using 5-fluorouracil (5-FU) and branched gold nanoshells (BGNSs) in a colorectal cancer model. BGNSs were synthesized via a seed-mediated method and characterized by electron microscopy and UV–vis spectroscopy, revealing an average diameter of 126.3 nm and a plasmon resonance peak at 800 nm, suitable for near-infrared (NIR) photothermal applications. In vitro assays using SW620-GFP colon cancer cells demonstrated a ≥90% reduction in cell viability after 24 h of combined treatment with 5-FU and BGNS under NIR irradiation. In vivo, xenograft-bearing nude mice received weekly intratumoral administrations of the combined therapy for four weeks. The group treated with 5-FU + BGNS + NIR exhibited a final tumor volume of 0.4 mm3 on day 28, compared to 1010 mm3 in the control group, corresponding to a tumor growth inhibition (TGI) of 100.74% (p < 0.001), which indicates not only complete inhibition of tumor growth but also regression below the initial tumor volume. Thermographic imaging confirmed that localized hyperthermia reached 45 ± 0.5 °C at the tumor site. Results: These findings suggest that the combination of 5-FU and BGNS-mediated hyperthermia may offer a promising strategy for enhancing therapeutic outcomes in patients with colorectal cancer while potentially minimizing systemic toxicity. Conclusions: This study highlights the potential of integrating nanotechnology with conventional chemotherapy for more effective and targeted cancer treatment. Full article
(This article belongs to the Special Issue Advanced Nanotechnology for Combination Therapy and Diagnosis)
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12 pages, 1699 KiB  
Article
Evaluation of Ear Thermographic Imaging as a Potential Variable for Detecting Hypocalcemia in Postpartum Holstein Dairy Cows
by Guilherme Violin, Nanako Mochizuki, Simon Stephen Abraham Warju, Megumi Itoh and Takahiro Aoki
Animals 2025, 15(14), 2055; https://doi.org/10.3390/ani15142055 - 11 Jul 2025
Viewed by 297
Abstract
Hypocalcemia is common in dairy cows within the first 72 h post-calving, and can be either clinical or subclinical. Early detection is critical, but traditional laboratory tests are time-consuming and cow-side tests remain costly. A classic symptom of hypocalcemia is reduced ear skin [...] Read more.
Hypocalcemia is common in dairy cows within the first 72 h post-calving, and can be either clinical or subclinical. Early detection is critical, but traditional laboratory tests are time-consuming and cow-side tests remain costly. A classic symptom of hypocalcemia is reduced ear skin temperature, which has been explored as a diagnostic tool in a previous study, but was not recommended at the end. Additionally, ambient temperature was found to strongly influence ear skin temperature, complicating diagnosis. The present study investigates infrared thermography of the ear as a potential non-invasive method for helping in the detection of hypocalcemia in Holstein cows. In order to differ from the previous study, with the goal of improving diagnosis accuracy, this research analyzed the entire ear temperature using infrared imaging software. Ambient temperature was factored in by categorizing samples into two groups based on air temperature: colder (−1.6 to 14.6 °C) and hotter (15.3 to 31.2 °C). Forty-two cows were monitored during the perinatal period, with blood samples and thermographic images taken twice a day until 48 h after calving. This study found that the median surface temperature of the ear correlated strongly with environmental temperature (r = 0.806, p < 0.001) and weakly with blood ionized calcium levels (r = 0.310, p < 0.01). In colder air temperatures, ear surface temperature was significantly different between healthy and hypocalcemic cows (p = 0.014). Logistic regression models were used to assess ionized calcium status based on different combinations of ear surface temperature, its difference from air temperature, and days in milk. In hotter air temperatures, only ear surface temperature, with no other covariates, was able to generate a valid model (p = 0.029). In colder air temperatures, multiple combinations of those variables generated valid models (p < 0.05), with the difference between ear and air temperature, together with days in milk, performing the best. Thus, this study concluded that ear surface temperature obtained through infrared thermography, while not promising for warmer environments, does show application potential for helping in the detection of hypocalcemia in colder environments. Full article
(This article belongs to the Section Cattle)
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16 pages, 322 KiB  
Article
Lumbar Temperature Map of Elderly Individuals with Chronic Low Back Pain—An Infrared Thermographic Analysis
by Nelson Albuquerque, Liliana Gonçalves, Wally Strasse, Joaquim Gabriel, Laetitia Teixeira and Pedro Cantista
Diagnostics 2025, 15(11), 1317; https://doi.org/10.3390/diagnostics15111317 - 23 May 2025
Viewed by 441
Abstract
Background/Objectives: Chronic low back pain (CLBP) is a prevalent condition that significantly impacts the aging population. Among non-invasive assessment tools, infrared thermography (IRT) has been highlighted as a radiation-free method to evaluate thermal variations in the lumbar region. However, its applicability in [...] Read more.
Background/Objectives: Chronic low back pain (CLBP) is a prevalent condition that significantly impacts the aging population. Among non-invasive assessment tools, infrared thermography (IRT) has been highlighted as a radiation-free method to evaluate thermal variations in the lumbar region. However, its applicability in clinical practice and correlation with functional and pain-related parameters remain unclear. This study aimed to analyze the thermal profile of the lumbar region in elderly individuals with CLBP and explore potential correlations between lumbar temperature patterns and clinical factors such as pain intensity and functional capacity. Methods: A cross-sectional observational study was performed in an outpatient setting. The population included thirty-one elderly individuals diagnosed with CLBP. IRT was used to assess the lumbar temperature distribution, including participants who reported pain radiating to the lower limbs. Pain intensity was measured using a numerical rating scale (0–10). The functional assessments included spine mobility tests and validated questionnaires evaluating clinical characteristics. Results: No significant differences in lumbar temperature patterns were observed among the participants. Additionally, no correlation was found between pain intensity and functional capacity based on a thermographic analysis. Nonetheless, individuals reporting lower fatigue levels and those with a higher body mass index (BMI) were generally associated with cooler thermal readings on the lumbar region’s thermographic maps. Conclusions: These findings suggest that IRT may require methodological refinements, including optimized technical specifications and image acquisition protocols, to enhance its applicability in assessing CLBP. Indeed, IRT might not be the most effective tool for evaluating pain-related thermal changes in elderly populations. Further research is needed to clarify its role in clinical assessments. Full article
(This article belongs to the Special Issue Advanced Musculoskeletal Imaging in Clinical Diagnostics)
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14 pages, 2145 KiB  
Article
Advanced AI-Driven Thermographic Analysis for Diagnosing Diabetic Peripheral Neuropathy and Peripheral Arterial Disease
by Albert Siré Langa, Jose Luis Lázaro-Martínez, Aroa Tardáguila-García, Irene Sanz-Corbalán, Sergi Grau-Carrión, Ibon Uribe-Elorrieta, Arià Jaimejuan-Comes and Ramon Reig-Bolaño
Appl. Sci. 2025, 15(11), 5886; https://doi.org/10.3390/app15115886 - 23 May 2025
Viewed by 892
Abstract
This study explores the integration of advanced artificial intelligence (AI) techniques with infrared thermography for diagnosing diabetic peripheral neuropathy (DPN) and peripheral arterial disease (PAD). Diabetes-related foot complications, including DPN and PAD, are leading causes of morbidity and disability worldwide. Traditional diagnostic methods, [...] Read more.
This study explores the integration of advanced artificial intelligence (AI) techniques with infrared thermography for diagnosing diabetic peripheral neuropathy (DPN) and peripheral arterial disease (PAD). Diabetes-related foot complications, including DPN and PAD, are leading causes of morbidity and disability worldwide. Traditional diagnostic methods, such as the monofilament test for DPN and ankle–brachial pressure index for PAD, have limitations in sensitivity, highlighting the need for improved solutions. Thermographic imaging, a non-invasive, cost-effective, and reliable tool, captures temperature distributions of the patient plantar surface, enabling the detection of physiological changes linked to these conditions. This study collected thermographic data from diabetic patients and employed convolutional neural networks (CNNs) and vision transformers (ViTs) to classify individuals as healthy or affected by DPN or PAD (not healthy). These neural networks demonstrated superior diagnostic performance, compared to traditional methods (an accuracy of 95.00%, a sensitivity of 100.00%, and a specificity of 90% in the case of the ResNet-50 network). The results underscored the potential of combining thermography with AI to provide scalable, accurate, and patient-friendly diagnostics for diabetic foot care. Future work should focus on expanding datasets and integrating explainability techniques to enhance clinical trust and adoption. Full article
(This article belongs to the Special Issue Applications of Sensors in Biomechanics and Biomedicine)
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17 pages, 5269 KiB  
Article
Thermography as a Method to Evaluate Temperature Changes in the Acropodial Region of a Warmblood Horse Following the Application of an Ice Boot Pack: A Pilot Study
by Cristian Zaha, Larisa Schuszler, Alexandru Ciresan, Tudor Căsălean, Irina Spataru, Iuliu Torda, Vlad Cocioba, Ioan Hutu, Janos Degi, Ciprian Rujescu and Roxana Dascălu
Appl. Sci. 2025, 15(10), 5524; https://doi.org/10.3390/app15105524 - 15 May 2025
Viewed by 423
Abstract
This pilot study evaluated the effectiveness of ice boots in cooling the metacarpal and coronary regions of a horse after training over 8 days (n = 8). Background: While cryotherapy is effective in managing exertional heat illness, stress fractures, and laminitis in [...] Read more.
This pilot study evaluated the effectiveness of ice boots in cooling the metacarpal and coronary regions of a horse after training over 8 days (n = 8). Background: While cryotherapy is effective in managing exertional heat illness, stress fractures, and laminitis in horses, conventional methods are often costly and impractical. This pilot study assessed the efficacy of ice boots as an accessible alternative for cooling the metacarpal and coronary regions post-training. Methods: A four-year-old Warmblood mare was trained on a treadmill over 8 days. An ice boot was applied to the right thoracic limb for 20 min post-exercise. Thermographic images were captured at six time points from pre-training to 30 min post-cooling. Mean temperatures in four regions were analyzed using the FLIR Tools software v6.4.18039.1003. Results: Post-training, metacarpal temperatures increased by 10.97 ± 0.46 °C (p = 0.000). Ice boot application reduced metacarpal temperature by 20.27 ± 0.22 °C (p = 0.001) and coronary band temperature by 5.28 ± 0.30 °C (p = 0.001), with altered thermal patterns visible on the imaging. Treated regions returned to baseline within 30 min, while the control limb took 50 min. Conclusions: Ice boots provide rapid, effective cooling and distinctive thermal pattern changes, offering a practical cryotherapy alternative for equine limb care post-training. These initial findings lay the groundwork for larger studies involving more horses under varied conditions, which will be necessary to confirm the results and establish clear guidelines for the clinical use of ice boots in equine practice. Full article
(This article belongs to the Special Issue Recent Progress and Applications of Infrared Thermography)
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18 pages, 10317 KiB  
Article
Advanced Thermal Imaging Processing and Deep Learning Integration for Enhanced Defect Detection in Carbon Fiber-Reinforced Polymer Laminates
by Renan Garcia Rosa, Bruno Pereira Barella, Iago Garcia Vargas, José Ricardo Tarpani, Hans-Georg Herrmann and Henrique Fernandes
Materials 2025, 18(7), 1448; https://doi.org/10.3390/ma18071448 - 25 Mar 2025
Viewed by 903
Abstract
Carbon fiber-reinforced polymer (CFRP) laminates are widely used in aerospace, automotive, and infrastructure industries due to their high strength-to-weight ratio. However, defect detection in CFRP remains challenging, particularly in low signal-to-noise ratio (SNR) conditions. Conventional segmentation methods often struggle with noise interference and [...] Read more.
Carbon fiber-reinforced polymer (CFRP) laminates are widely used in aerospace, automotive, and infrastructure industries due to their high strength-to-weight ratio. However, defect detection in CFRP remains challenging, particularly in low signal-to-noise ratio (SNR) conditions. Conventional segmentation methods often struggle with noise interference and signal variations, leading to reduced detection accuracy. In this study, we evaluate the impact of thermal image preprocessing on improving defect segmentation in CFRP laminates inspected via pulsed thermography. Polynomial approximations and first- and second-order derivatives were applied to refine thermographic signals, enhancing defect visibility and SNR. The U-Net architecture was used to assess segmentation performance on datasets with and without preprocessing. The results demonstrated that preprocessing significantly improved defect detection, achieving an Intersection over Union (IoU) of 95% and an F1-Score of 99%, outperforming approaches without preprocessing. These findings emphasize the importance of preprocessing in enhancing segmentation accuracy and reliability, highlighting its potential for advancing non-destructive testing techniques across various industries. Full article
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27 pages, 22179 KiB  
Article
Compensation-Based Full-Filed Thermal Homogenization for Contrast Enhancement in Long Pulse Thermographic Imaging
by Yoonjae Chung, Chunyoung Kim, Seongmin Kang, Wontae Kim and Hyunkyu Suh
Sensors 2025, 25(7), 1969; https://doi.org/10.3390/s25071969 - 21 Mar 2025
Viewed by 338
Abstract
Non-destructive testing (NDT) plays a crucial role in ensuring the structural integrity and safety of industrial facilities and components. Long pulse thermography (LPT), a form of active thermographic testing (ATT), has gained attention for its ability to detect subsurface defects efficiently. However, non-uniform [...] Read more.
Non-destructive testing (NDT) plays a crucial role in ensuring the structural integrity and safety of industrial facilities and components. Long pulse thermography (LPT), a form of active thermographic testing (ATT), has gained attention for its ability to detect subsurface defects efficiently. However, non-uniform thermal excitation and environmental noise often degrade the accuracy of defect detection. This study proposes an advanced thermographic inspection technique incorporating a halogen array (HA) lamp and a compensation methodology to enhance the reliability of defect detection. Two compensation methods, namely absolute temperature compensation (ATC) and temperature rate compensation (TRC), were developed to correct non-uniform thermal loads and improve the defect contrast. Experimental validation was conducted on A-type and B-type mock-up specimens with artificial subsurface defects (10–90% depth). The results demonstrated a significant enhancement in the signal-to-noise ratio (SNR), reaching up to a 42 dB improvement in severe defects. Furthermore, a quantitative evaluation method was proposed using SNR-based defect depth estimation models, improving the accuracy of defect sizing. This approach eliminates the need for complex amplitude and phase transformations, enabling direct defect assessment from temperature thermograms. Full article
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26 pages, 3654 KiB  
Article
Resistance Welding Quality Through Artificial Intelligence Techniques
by Luis Alonso Domínguez-Molina, Edgar Rivas-Araiza, Juan Carlos Jauregui-Correa, Jose Luis Gonzalez-Cordoba, Jesús Carlos Pedraza-Ortega and Andras Takacs
Sensors 2025, 25(6), 1744; https://doi.org/10.3390/s25061744 - 12 Mar 2025
Viewed by 1170
Abstract
Quality assessment of the resistance spot welding process (RSW) is vital during manufacturing. Evaluating the quality without altering the joint material’s physical and mechanical properties has gained interest. This study uses a trained computer vision model to propose a cheap, non-destructive quality-evaluation methodology. [...] Read more.
Quality assessment of the resistance spot welding process (RSW) is vital during manufacturing. Evaluating the quality without altering the joint material’s physical and mechanical properties has gained interest. This study uses a trained computer vision model to propose a cheap, non-destructive quality-evaluation methodology. The methodology connects the welding input and during-process parameters with the output visual quality information. A manual resistance spot welding machine was used to monitor and record the process input and output parameters to generate the dataset for training. The welding current, welding time, and electrode pressure data were correlated with the welding spot nugget’s quality, mechanical characteristics, and thermal and visible images. Six machine learning models were trained on visible and thermographic images to classify the weld’s quality and connect the quality characteristics (pull force and welding diameter) and the manufacturing process parameters with the visible and thermographic images of the weld. Finally, a cross-validation method validated the robustness of these models. The results indicate that the welding time and the angle between electrodes are highly influential parameters on the mechanical strength of the joint. Additionally, models using visible images of the welding spot exhibited superior performance compared to thermal images. Full article
(This article belongs to the Special Issue Wireless Sensor Networks for Condition Monitoring)
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14 pages, 10109 KiB  
Article
Using Infrared Thermography to Assess Musculoskeletal Overload in the Hands of Harvester Operators
by Alysson Braun Martins, Marcos Leal Brioschi, Carla Krulikowski Rodrigues and Eduardo da Silva Lopes
Forests 2025, 16(3), 429; https://doi.org/10.3390/f16030429 - 27 Feb 2025
Viewed by 547
Abstract
Mechanization in timber harvesting has improved the comfort and safety of operator workstations. However, there is an imminent ergonomic risk in relation to the repetition of movements, which can cause musculoskeletal injuries. The aim of this study was to apply infrared thermography to [...] Read more.
Mechanization in timber harvesting has improved the comfort and safety of operator workstations. However, there is an imminent ergonomic risk in relation to the repetition of movements, which can cause musculoskeletal injuries. The aim of this study was to apply infrared thermography to identify musculoskeletal overload in the hand region of harvester operators. This study was conducted on wood harvesting of homogeneous Eucalyptus urophylla × Eucalyptus grandis stands using a forestry harvester tractor. Thermographic images were taken of seven operators at the beginning and end of the working day during six days of the shift. The maximum, average, and minimum temperatures were measured in 14 hand regions of interest (ROI), verifying the existence of a difference between the beginning and the end of work (p-value < 5%) by using the Mann–Whitney test. The operators presented hyperradiant temperature variation in the hand region after work, with a variation above 2.5 °C, indicating a high degree of abnormality. There was greater temperature variation in the right hand (3.7 °C) due to the greater concentration of commands on the machine’s right joystick. Infrared thermography has proven to be an important tool for functional imaging diagnosis, contributing to the reduction in risks of developing Repetitive Strain Injury/Work-Related Musculoskeletal Disorder (RSI-WMSD). Full article
(This article belongs to the Special Issue Addressing Forest Ergonomics Issues: Laborers and Working Conditions)
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25 pages, 2484 KiB  
Article
Automatic Fault Classification in Photovoltaic Modules Using Denoising Diffusion Probabilistic Model, Generative Adversarial Networks, and Convolutional Neural Networks
by Carlos Roberto da Silveira Junior, Carlos Eduardo Rocha Sousa and Ricardo Henrique Fonseca Alves
Energies 2025, 18(4), 776; https://doi.org/10.3390/en18040776 - 7 Feb 2025
Cited by 2 | Viewed by 963
Abstract
Current techniques for fault analysis in photovoltaic (PV) systems plants involve either electrical performance measurements or image processing, as well as line infrared thermography for visual inspection. Deep convolutional neural networks (CNNs) are machine learning algorithms that perform tasks involving images, such as [...] Read more.
Current techniques for fault analysis in photovoltaic (PV) systems plants involve either electrical performance measurements or image processing, as well as line infrared thermography for visual inspection. Deep convolutional neural networks (CNNs) are machine learning algorithms that perform tasks involving images, such as image classification and object recognition. However, to train a model effectively to recognize different patterns, it is crucial to have a sufficiently balanced dataset. Unfortunately, this is not always feasible owing to the limited availability of publicly accessible datasets for PV thermographic data and the unequal distribution of different faults in real-world systems. In this study, three data augmentation techniques—geometric transformations (GTs), generative adversarial networks (GANs), and the denoising diffusion probabilistic model (DDPM)—were combined with a CNN to classify faults in PV modules through thermographic images and identify the type of fault in 11 different classes (i.e., soiling, shadowing, and diode). Through the cross-validation method, the main results found with the Wasserstein GAN (WGAN) and DDPM networks combined with the CNN for anomaly classification achieved testing accuracies of 86.98% and 89.83%, respectively. These results demonstrate the effectiveness of both networks for accurately classifying anomalies in the dataset. The results corroborate the use of the diffusion model as a PV data augmentation technique when compared with other methods such as GANs and GTs. Full article
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17 pages, 40755 KiB  
Article
Data-Driven Clustering of Plantar Thermal Patterns in Healthy Individuals: An Insole-Based Approach to Foot Health Monitoring
by Mark Borg, Stephen Mizzi, Robert Farrugia, Tiziana Mifsud, Anabelle Mizzi, Josef Bajada and Owen Falzon
Bioengineering 2025, 12(2), 143; https://doi.org/10.3390/bioengineering12020143 - 1 Feb 2025
Viewed by 1210
Abstract
Monitoring plantar foot temperatures is essential for assessing foot health, particularly in individuals with diabetes at increased risk of complications. Traditional thermographic imaging measures foot temperatures in unshod individuals lying down, which may not reflect thermal characteristics of feet in shod, active, real-world [...] Read more.
Monitoring plantar foot temperatures is essential for assessing foot health, particularly in individuals with diabetes at increased risk of complications. Traditional thermographic imaging measures foot temperatures in unshod individuals lying down, which may not reflect thermal characteristics of feet in shod, active, real-world conditions. These controlled settings limit understanding of dynamic foot temperatures during daily activities. Recent advancements in wearable technology, such as insole-based sensors, overcome these limitations by enabling continuous temperature monitoring. This study leverages a data-driven clustering approach, independent of pre-selected foot regions or models like the angiosome concept, to explore normative thermal patterns in shod feet with insole-based sensors. Data were collected from 27 healthy participants using insoles embedded with 21 temperature sensors. The data were analysed using clustering algorithms, including k-means, fuzzy c-means, OPTICS, and hierarchical clustering. The clustering algorithms showed a high degree of similarity, with variations primarily influenced by clustering granularity. Six primary thermal patterns were identified, with the “butterfly pattern” (elevated medial arch temperatures) predominant, representing 51.5% of the dataset, aligning with findings in thermographic studies. Other patterns, like the “medial arch + metatarsal area” pattern, were also observed, highlighting diverse yet consistent thermal distributions. This study shows that while normative thermal patterns observed in thermographic imaging are reflected in insole data, the temperature distribution within the shoe may better represent foot behaviour during everyday activities, particularly when enclosed in a shoe. Unlike thermal imaging, the proposed in-shoe system offers the potential to capture dynamic thermal variations during ambulatory activities, enabling richer insights into foot health in real-world conditions. Full article
(This article belongs to the Special Issue Body-Worn Sensors for Biomedical Applications)
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31 pages, 6912 KiB  
Article
Enhancing Early Breast Cancer Detection with Infrared Thermography: A Comparative Evaluation of Deep Learning and Machine Learning Models
by Reem Jalloul, Chethan Hasigala Krishnappa, Victor Ikechukwu Agughasi and Ramez Alkhatib
Technologies 2025, 13(1), 7; https://doi.org/10.3390/technologies13010007 - 26 Dec 2024
Cited by 4 | Viewed by 3592
Abstract
Breast cancer remains one of the most prevalent and deadly cancers affecting women worldwide. Early detection is crucial, particularly for younger women, as traditional screening methods like mammography often struggle with accuracy in cases of dense breast tissue. Infrared thermography offers a non-invasive [...] Read more.
Breast cancer remains one of the most prevalent and deadly cancers affecting women worldwide. Early detection is crucial, particularly for younger women, as traditional screening methods like mammography often struggle with accuracy in cases of dense breast tissue. Infrared thermography offers a non-invasive imaging alternative that enhances early detection by capturing subtle thermal variations indicative of breast abnormalities. This study investigates and compares the performance of various deep learning and machine learning models in analyzing thermographic data to classify breast tissue as healthy, benign, or malignant. To maximize detection accuracy, data preprocessing, feature extraction, and dimensionality reduction were implemented to isolate distinguishing characteristics across tissue types. Leveraging advanced feature extraction and visualization techniques inspired by geospatial data methodologies, we evaluated several deep learning architectures and classical classifiers using the DRM-IR and Breast Thermography Mendeley thermal datasets. Among the tested models, the ResNet152 architecture combined with a Support Vector Machine (SVM) classifier delivered the highest performance, achieving 97.62% accuracy, 95.79% precision, 98.53% recall, 94.52% specificity, an F1 score of 97.16%, an area under the curve (AUC) of 99%, a latency of 0.06 s, and CPU utilization of 88.66%. These findings underscore the potential of integrating infrared thermography with advanced deep learning and machine learning approaches to significantly improve the accuracy and efficiency of breast cancer detection, supporting its role as a valuable tool for early diagnosis. Full article
(This article belongs to the Section Information and Communication Technologies)
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23 pages, 7813 KiB  
Article
The Use of Hybrid CNN-RNN Deep Learning Models to Discriminate Tumor Tissue in Dynamic Breast Thermography
by Andrés Munguía-Siu, Irene Vergara and Juan Horacio Espinoza-Rodríguez
J. Imaging 2024, 10(12), 329; https://doi.org/10.3390/jimaging10120329 - 21 Dec 2024
Cited by 4 | Viewed by 2845
Abstract
Breast cancer is one of the leading causes of death for women worldwide, and early detection can help reduce the death rate. Infrared thermography has gained popularity as a non-invasive and rapid method for detecting this pathology and can be further enhanced by [...] Read more.
Breast cancer is one of the leading causes of death for women worldwide, and early detection can help reduce the death rate. Infrared thermography has gained popularity as a non-invasive and rapid method for detecting this pathology and can be further enhanced by applying neural networks to extract spatial and even temporal data derived from breast thermographic images if they are acquired sequentially. In this study, we evaluated hybrid convolutional-recurrent neural network (CNN-RNN) models based on five state-of-the-art pre-trained CNN architectures coupled with three RNNs to discern tumor abnormalities in dynamic breast thermographic images. The hybrid architecture that achieved the best performance for detecting breast cancer was VGG16-LSTM, which showed accuracy (ACC), sensitivity (SENS), and specificity (SPEC) of 95.72%, 92.76%, and 98.68%, respectively, with a CPU runtime of 3.9 s. However, the hybrid architecture that showed the fastest CPU runtime was AlexNet-RNN with 0.61 s, although with lower performance (ACC: 80.59%, SENS: 68.52%, SPEC: 92.76%), but still superior to AlexNet (ACC: 69.41%, SENS: 52.63%, SPEC: 86.18%) with 0.44 s. Our findings show that hybrid CNN-RNN models outperform stand-alone CNN models, indicating that temporal data recovery from dynamic breast thermographs is possible without significantly compromising classifier runtime. Full article
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16 pages, 6198 KiB  
Article
Modeling Cost-Effectiveness of Photovoltaic Module Replacement Based on Quantitative Assessment of Defect Power Loss
by Victoria Lofstad-Lie, Bjørn Lupton Aarseth, Nathan Roosloot, Erik Stensrud Marstein and Torbjørn Skauli
Solar 2024, 4(4), 728-743; https://doi.org/10.3390/solar4040034 - 19 Dec 2024
Cited by 1 | Viewed by 931
Abstract
The degradation of solar photovoltaic (PV) modules over time, which are aggravated by defects, significantly affects the performance of utility-scale PV parks. This study presents a quantitative assessment of the power loss from module defects and evaluates the cost-effectiveness of replacing defective modules [...] Read more.
The degradation of solar photovoltaic (PV) modules over time, which are aggravated by defects, significantly affects the performance of utility-scale PV parks. This study presents a quantitative assessment of the power loss from module defects and evaluates the cost-effectiveness of replacing defective modules at various stages of degradation. A module test site was established in Norway with six different defects, and continuous thermographic monitoring, combined with light IV measurements and electroluminescence (EL) imaging, provides partial support for further calculations on the long-term effects of the defects. The cumulative module energy loss is calculated over a 25-year park lifespan under both Norwegian and Chilean environmental conditions, with the latter representing higher solar irradiation levels. The energy gain from replacing the defective modules at various stages of degradation is compared to the costs of replacement, both for infant-life failures and mid-life failures. It is likely not beneficial to replace minor infant-life defects of 1% power loss in low-irradiation regions like Norway. For Chilean conditions, it can be cost-effective, but primarily if the module is replaced around mid park life, which gives a larger yield when replaced with a new module. For more severe defects of 10% loss, the replacement gain is above the replacement cost for high-irradiation locations, and replacing the 33% power loss defect is cost-effective for both locations, even when discovered late in the park lifetime. It is primarily beneficial to replace mid-life defects in high-irradiation locations. Full article
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