Indirect Thermographic Measurement of the Temperature of a Transistor Die during Pulse Operation.

This paper presents aspects related to the indirect thermographic measurement of a C2M0280120D transistor in pulse mode. The tested transistor was made on the basis of silicon carbide and is commonly used in many applications. During the research, the pulse frequency was varied from 1 kHz to 800 kHz. The transistor case temperature was measured using a Flir E50 thermographic camera and a Pt1000 sensor. The transistor die temperature was determined based on the voltage drop on the body diode and the known characteristics between the voltage drop on the diode and the temperature of the die. The research was carried out in accordance with the presented measuring standards and maintaining the described conditions. The differences between the transistor case temperature and the transistor die temperature were also determined based on simulation work performed in Solidworks 2020 SP05. For this purpose, a three-dimensional model of the C2M0280120D transistor was created and the materials used in this model were selected; the methodology for selecting the model parameters is discussed. The largest recorded difference between the case temperature and the junction temperature was 27.3 °C. The use of a thermographic camera allows the transistor's temperature to be determined without the risk of electric shock. As a result, it will be possible to control the C2M0280120D transistor in such a way so as not to damage it and to optimally select its operating point.

The Relationship between the Infrared Eye Temperature of Beef Cattle and Associated Biological Responses at High Environmental Temperatures.

Cattle in regions with high ambient temperatures are at risk of heat stress. Early detection is important to allow action to be taken to minimise the risks to cattle exposed to thermal stress. This study aimed to investigate the impact of heat stress on IRT-Eye temperature and its association with the behavioural and physiological responses of heat-stressed Angus steers (n = 24) on finisher and or substituted diets. Overall, 2 cohorts of 12 Angus steers were individually housed in a climate-controlled facility to examine responses to heat stress when fed on a standard finisher diet, based on a high percentage of cereal grains, and on a substituted diet in which 8% of the grains were replaced by an isoenergetic amount of lucerne hay. Exposing feedlot cattle to hot environmental conditions increased IRT-Eye temperature, which had a strong association with behaviour and physiology. There was no evidence of differences between the different dietary cohorts. The cattle with increased IRT-Eye temperature showed stress-related responses, including a downward-facing head, ears directed backwards, and other indicators of heat stress such as increased panting, standing, and increased rumen temperature. The strong association of IRT-Eye temperature with stress-related behaviours, as well as with rumen temperature and panting behaviour, highlights the potential for IRT-Eye to be utilised as a non-invasive tool to assess cattle responses in hot conditions.

Cryosurgery of eyelid actinic keratosis and the effect of adrenaline in local anesthetics - temperature mapping using IR thermography.

PURPOSE: The efficacy of cryosurgery is believed to depend on the thaw time. The presence of adrenaline in local anesthetics affects blood perfusion, and may thus also affect the thaw time. The aim of the present study was to use IR thermography to monitor the tissue temperature during cryosurgery of actinic keratosis, and to assess the effect of adrenaline in local anesthetics. METHODS: Twelve patients with actinic keratosis in the periorbital region underwent cryosurgery. The temperature was continuously mapped using a high-precision IR camera and was also visually assessed by the surgeon. The results obtained when employing local anesthetics with and without adrenaline were compared. RESULTS: The temperature change during thawing showed a triphasic pattern. The thaw time was significantly longer when using an anesthetic with adrenaline. This was observed with both IR thermography and by visual observation. CONCLUSIONS: The findings indicate that a longer freezing time may be needed when using a local anesthetic without adrenaline to achieve the same cryo-effect as when using a local anesthetic with adrenaline. A larger clinical trial is needed on the effects of using local anesthetics with and without adrenaline to treat actinic keratosis, for example, the clearance rate, before recommendations can be made concerning their use.

Nondestructive Testing of 3D Printed Fiber-Reinforced Polymeric Composites: An Experimental Critical Comparison.

Polymer matrix composite (PMC) materials produced by additive manufacturing are a promising solution with several applications in industry. The presence of defects due to fabrication could undermine the performance of the component structure. PMC performance has been extensively studied using destructive tests, but reliable nondestructive testing (NDT) techniques are essential. In this study, PMC with unidirectional fibers were 3D printed with an adapted conventional fused filament fabrication printer. The matrix material was polylactic acid, and three different reinforcement fibers were used: Kevlar®, carbon, and glass fibers. The samples were 3D printed with artificial defects, to simulate delamination's 0.5 mm thick. Four NDT techniques were explored, benchmarking the inspection of PMC envisaging an automated noncontact imaging inspection for easier result interpretation. Active pulse thermography, air-coupled ultrasounds, continuous wave terahertz, and digital X-ray were the techniques chosen, and a critical comparison is presented, evaluating the performance of each technique in the detection of defects. NDT technique diversity, complementarity, and redundancy improve inspection reliability, as there is not a single inspection technique that can cover all material defects or characteristics.

Segmental vitiligo distribution follows the underlying arterial blood supply territory: a hypothesis based on anatomo-clinical, pathological and physio-pathological studies.

Background: Segmental vitiligo (SV) is a subset of vitiligo typically characterized by its unilateral distribution. The pathogenesis of SV remains unclear, and until now the two main patterns proposed for SV have lacked biological support. This calls for a new approach. Objectives: Use data obtained from anatomo-clinical, pathological, and physio-pathological studies to formulate a new hypothesis on segmental vitiligo distribution and its pathogenesis. Methods: Using transparent templates of local arterial blood supply, we evaluated anatomical correspondence (AC) in 140 SV lesions according to the number of SV lesions that fit within the corresponding arterial blood-supply areas. SV lesions were graded as 1 (moderate: AC < 50%), 2 (good: AC > 50%), or 3 (excellent: AC of all lesions). To support this anatomical investigation, we searched for complementary assessments according to the activity of SV lesions. Arterial and periarterial network impairment and inflammatory infiltration were histologically studied using nerve growth factor (NGF) and CD4 and CD8 monoclonal antibodies. Increased blood flow of the underlying arteries was also investigated using thermography and ultrasonography. Results: We recruited 140 patients with a sex ratio of 0.8 and mean age 26.13 years. Localizations: head and neck 84.28%; trunk 6.42%; upper limb 5%; genital areas 2.14%; lower limb 1.42%. The AC of each SV lesion with the underlying artery blood supply territory was rated as 72% excellent; 16% good; and 12% moderate. Histologically (40 patients), we found some periarterial network impairments. Thermal asymmetry was significantly associated with active SV (p < 0.001). Conclusion: We hypothesized that SV distribution corresponds to the underlying artery blood-supply territory.

The correlation between sub-epidermal moisture assessment and other early indicators of pressure ulcer development: A prospective cohort observational study. Part 2. The correlation between sub-epidermal moisture assessment, temperature, epidermal hydration and pain.

There is growing interest in the roles of temperature, epidermal hydration (EH) and pain in pressure ulcer (PU) development. Investigating correlations between these measures and sub-epidermal moisture (SEM) will address this knowledge deficit. A prospective observational study enrolled 60 surgical patients from February to November 2021. SEM, temperature, EH and pain were assessed using a SEM scanner, thermography imaging, skin hydration device and numeric pain intensity scale, respectively. Measurements were taken at the sacrum, both heels and a control site, before and after surgery for 3 days. Data were analysed using Pearson or Spearman's correlation. Of the participants, 50% were male with a mean age of 58 years (±13.46). Low positive/negative correlations between SEM and temperature were found at the sacrum. However, after removing outliers, these results were not statistically significant. Other sites and follow-up days showed negligible correlations. No evidence of a correlation, to low correlations between SEM and EH were observed, but unreliable due to little variation in EH at the heels. Pain showed negligible correlations with SEM. This study did not find consistent evidence of a correlation between SEM, temperature, EH and pain, highlighting the unreliability of temperature and EH for early PU detection. Post-operative pain may also confound accurate pain assessments.

A Randomized Clinical Trial Study on the Prevention Strategy and Early Detection of Ulcer Recurrence in Patients with Type 2 Diabetes Mellitus Using the Risk of Recurrence Ulcer Tool.

TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifies: NCT06434922.

Portable noninvasive technologies for early breast cancer detection: A systematic review.

Breast cancer remains a leading cause of cancer mortality worldwide, with early detection crucial for improving outcomes. This systematic review evaluates recent advances in portable non-invasive technologies for early breast cancer detection, assessing their methods, performance, and potential for clinical implementation. A comprehensive literature search was conducted across major databases for relevant studies published between 2015 and 2024. Data on technology types, detection methods, and diagnostic performance were extracted and synthesized from 41 included studies. The review examined microwave imaging, electrical impedance tomography (EIT), thermography, bioimpedance spectroscopy (BIS), and pressure sensing technologies. Microwave imaging and EIT showed the most promise, with some studies reporting sensitivities and specificities over 90 %. However, most technologies are still in early stages of development with limited large-scale clinical validation. These innovations could complement existing gold standards, potentially improving screening rates and outcomes, especially in underserved populations, whiles decreasing screening waiting times in developed countries. Further research is therefore needed to validate their clinical efficacy, address implementation challenges, and assess their impact on patient outcomes before widespread adoption can be recommended.

Thermal Evaluation of Bone Drilling with a One-Drill Protocol.

This study evaluates the thermal impact of a one-drill protocol for osteotomy preparation in dental implant surgery. Our findings demonstrate a significant reduction in heat generation compared to traditional sequential drilling, suggesting potential benefits for implant osseointegration and patient comfort. Specifically, the one-drill protocol was associated with lower peak temperatures and a reduced duration of elevated temperatures. These findings suggest that the one-drill protocol may contribute to improved implant stability and reduce the risk of thermal-induced bone damage. While further research is needed to confirm these findings in clinical settings, the results of this study provide promising evidence for the potential advantages of the one-drill protocol in dental implant surgery. Additionally, the one-drill protocol may offer simplified surgical workflows and reduced instrument management, potentially leading to improved efficiency and cost-effectiveness in dental implant procedures.

Infrared Thermography Sensor in the Analysis of Acute Metabolic Stress Response during Race Walking Competition.

Introduction: Due to the possible impact of the thermoregulatory process on sports performance, it is necessary to explore the existing relationships between kinetic, mechanical, and physiological variables. The objective of this study was to evaluate metabolic stress using thermography in the lower limb after the Spanish Championship 2023 walk. Method: A descriptive study was carried out on national and international race walkers before and after the 2023 Spanish Championships. The participants performed different tests within the same circuit. Five walkers completed the long-distance race of 35 km, four walkers completed the middle-distance race of 20 km and finally, two walkers completed the short-distance race of 10 km. Result: Statistically significant changes were observed in the lower limbs of the walkers after completing the test. We observed a decrease in skin temperature in all the anatomical regions analyzed, except for the back of the leg. More specifically, the decrease was in the hip (-1.92 °C: p = 0.004), quadriceps, hamstrings (-1.23 °C: p = 0.002), and tibia (-1.23 °C: p = 0.030). However, in the posterior region of the leg, a significant increase in temperature was observed (+0.50 °C: p = 0.011) following the competition. Discussion and Conclusions: The findings in this descriptive investigation support the notion that thermography may serve as a useful tool in the acute analysis of muscle functional activation and metabolic response in professional marching athletes. Moreover, the results confirmed that the change in skin temperature is the result of a variation in acute metabolic and functional activation in the lower extremities of race walkers during competition, with infrared thermography representing an instrument capable of detecting such a change in a rapid and non-invasive manner.

Fully Interpretable Deep Learning Model Using IR Thermal Images for Possible Breast Cancer Cases.

Breast cancer remains a global health problem requiring effective diagnostic methods for early detection, in order to achieve the World Health Organization's ultimate goal of breast self-examination. A literature review indicates the urgency of improving diagnostic methods and identifies thermography as a promising, cost-effective, non-invasive, adjunctive, and complementary detection method. This research explores the potential of using machine learning techniques, specifically Bayesian networks combined with convolutional neural networks, to improve possible breast cancer diagnosis at early stages. Explainable artificial intelligence aims to clarify the reasoning behind any output of artificial neural network-based models. The proposed integration adds interpretability of the diagnosis, which is particularly significant for a medical diagnosis. We constructed two diagnostic expert models: Model A and Model B. In this research, Model A, combining thermal images after the explainable artificial intelligence process together with medical records, achieved an accuracy of 84.07%, while model B, which also includes a convolutional neural network prediction, achieved an accuracy of 90.93%. These results demonstrate the potential of explainable artificial intelligence to improve possible breast cancer diagnosis, with very high accuracy.

Extremely Low Thermal Resistance of ß-Ga2O3 MOSFETs by Co-integrated Design of Substrate Engineering and Device Packaging.

Gallium oxide (Ga2O3) emerges as a promising ultrawide bandgap semiconductor, which is expected to surpass the performance of current wide bandgap materials, like GaN and SiC, in electronic devices. However, widespread application of Ga2O3 is hindered by its extremely low thermal conductivity and lack of effective device-level thermal management strategies. In this work, Ga2O3 metal-oxide-semiconductor field-effect transistors (MOSFETs) are fabricated by conducting co-integrated design of substrate engineering with layer transferring and device packaging. 3D Raman thermography is introduced as a novel method to analyze the temperature distribution within the device, which provides valuable insights into their thermal performances. A high-quality Ga2O3-SiC heterogeneous integrated material is successfully fabricated with an extremely low interface thermal resistance of 6.67 ± 2 m2·K/GW. Compared to the homoepitaxial Ga2O3 MOSFETs, the degradation of Ion/Ioff in Ga2O3-SiC MOSFETs is decreased by 1.5 orders of magnitude, and that of Ron is decreased by 31%, showing the great thermal stability of Ga2O3-SiC MOSFETs. With the additional device packaging, a significant one order-of-magnitude reduction in the thermal resistance of the Ga2O3-SiC MOSFET is achieved, reaching a record-low value of 4.45 K·mm/W in the reported Ga2O3 MOSFETs. This work demonstrates an efficient strategy for device-level thermal management in next-generation Ga2O3 power and RF applications.

Protocol to evaluate human thermoregulation before and after thermal stress.

Problem and motivation: The human body dissipates 60 % of its heat by emitting infrared radiation, it can be studied using Infrared Thermography (IRT). IRT images serve as thermal maps of the body, useful in medical applications to investigate the physiopathological of diseases that present symptoms such as swelling, pain, infection, rash, and increased local skin temperature. Aim: To design a protocol to capture IRT images before and after physical activity. The protocol collects skin temperature data of the entire body, in the frontal (anterior and posterior) and sagittal (right and left) planes. Methodology: The protocol was designed considering clinical, environmental, and technical factors and ensuring its reproducibility in both healthy and pathological populations. Thermographic images were acquired both at rest and after thermal stress (modified Bruce test). In addition, questionnaires were prepared to collect and store information on demographic data, core temperature, environmental conditions, pain perception, and level of physical activity. Results: The protocol combines the acquisition of IRT images with the application of the modified Bruce protocol on a treadmill as a thermal stress generator. Further impact: This protocol offers a valuable tool for studying the thermoregulatory capacity of the human body in the presence of different medical conditions.

Comparison of infrared thermography of the face between mouth-breathing and nasal-breathing children.

PURPOSE: To compare the temperature of thermoanatomic points and areas of the upper and lower lips between mouth-breathing and nasal-breathing children. METHODS: This cross-sectional observational study had a sample of 30 nasal-breathing and 30 mouth-breathing children aged 4 to 11 years. One front-view, one left-view, and one right-view infrared thermogram of the face were acquired from each participant. A total of 14 thermoanatomic points plus the upper lip and lower lip areas were marked on the front-view thermograms, while on the side-view thermograms, six thermoanatomic points were marked. The research also calculated the difference between the temperature of the upper and lower lip areas (∆T area) and between the temperature of the points on the upper and lower lips (∆T points). The normalized mean temperatures of points and areas and temperature differences were compared between groups with the t-test and Mann-Whitney test. RESULTS: The temperature of the thermoanatomic points closest to the lip (nasolabial, Labial Commissure, and lower labial), areas of the lips, and external acoustic meatus was lower in mouth breathers than in nasal breathers, which did not happen for most other points. ∆T area and ∆T points were not different between the groups. CONCLUSION: Thermography is a promising complementary diagnostic tool, since showed mouth-breathing children had lower temperatures in the region of the lips than nasal breathers.

Novel Diagnostic Approach for Acute Pharyngitis: Combining Machine Learning With Thermal Imaging.

We evaluated the effect of infrared thermography (IRT) on the clinical assessment of bacterial and viral pharyngitis and its impact on the predictive value of the McIsaac score algorithm for streptococcal pharyngitis in children. We also investigated if IRT could distinguish between bacterial and viral pharyngitis. The study included children aged 2-17 years presenting with sore throat and fever over 38°C from November 1, 2021, to April 30, 2022. Of the 76 assessed children, 16 were excluded due to missing data or technical issues, leaving 60 children (32 males, 28 females) divided into three groups: Group A with streptococcal pharyngitis (N = 30), viral pharyngitis (N = 16), and healthy controls (N = 14). McIsaac score and IRT imaging showed a 90% positive predictive value for streptococcal pharyngitis. While IRT alone could not distinguish between bacterial and viral infections, it significantly increased the predictive value when combined with the McIsaac score.

Millimeter wave radiation to measure blood flow in healthy human subjects.

Objective.Peripheral Artery Disease (PAD) is a progressive cardiovascular condition affecting 8-10 million adults in the United States. PAD elevates the risk of cardiovascular events, but up to 50% of people with PAD are asymptomatic and undiagnosed. In this study, we tested the ability of a device, REFLO (Rapid Electromagnetic FLOw), to identify low blood flow using electromagnetic radiation and dynamic thermography toward a non-invasive PAD diagnostic.Approach.During REFLO radio frequency (RF) irradiation, the rate of temperature increase is a function of the rate of energy absorption and blood flow to the irradiated tissue. For a given rate of RF energy absorption, a slow rate of temperature increase implies a large blood flow rate to the tissue. This is due to the cooling effect of the blood. Post-irradiation, a slow rate of temperature decrease is associated with a low rate of blood flow to the tissue. Here, we performed two cohorts of controlled flow experiments on human calves during baseline, occluded, and post-occluded conditions. Nonlinear regression was used to fit temperature data and obtain the rate constant, which was used as a metric for blood flow.Main results.In the pilot study, (N= 7) REFLO distinguished between baseline and post-occlusion during the irradiation phase, and between baseline and occlusion in the post-irradiation phase. In the reliability study, (N= 5 with 3 visits each), two-way ANOVA revealed that flow and subject significantly affected skin heating and cooling rates, while visit did not.Significance.Results suggest that MMW irradiation can be used to distinguish between blood flow rates in humans. Utilizing the rate of skin cooling rather than heating is more consistent for distinguishing flow. Future modifications and clinical testing will aim to improve REFLO's ability to distinguish between flow rates and evaluate its ability to accurately identify PAD.

Thermal Reading of Texts Buried in Historical Bookbindings.

In the manufacture of ancient books, it was quite common to insert written scraps belonging to earlier library material into bookbindings. For scholars like codicologists and paleographers, it is extremely important to have the possibility of reading the text lying on such scraps without dismantling the book. In this regard, in this paper, we report on the detection of these texts by means of infrared (IR) pulsed thermography (PT), which, in recent years, has been specifically proven to be an effective tool for the investigation of Cultural Heritage. In particular, we present a quantitative analysis based, for the first time, on PT images obtained from books of historical relevance preserved at the Biblioteca Angelica in Rome. The analysis has been carried out by means of a theoretical model for the PT signal, which makes use of two image parameters, namely, the distortion and the contrast, related to the IR readability of the buried texts. As shown in this paper, the good agreement between the experimental data obtained in the historical books and the theoretical analysis proved that the capability of the adopted PT method could be fruitfully applied, in real case studies, to the detection of buried texts and to the quantitative characterization of the parameters affecting their thermal readability.

The Effect of Dimple Insole Design on the Plantar Temperature and Pressure in People with Diabetes and in Healthy Individuals.

An increase in plantar pressure and skin temperature is commonly associated with an increased risk of diabetic foot ulcers. However, the effect of insoles in reducing plantar temperature has not been commonly studied. The aim was to assess the effect of walking in insoles with different features on plantar temperature. Twenty-six (F/M:18/8) participants-13 with diabetes and 13 healthy, aged 55.67 ± 9.58 years-participated in this study. Skin temperature at seven plantar regions was measured using a thermal camera and reported as the difference between the temperature after walking with an insole for 20 m versus the baseline temperature. The mixed analyses of variance indicated substantial main effects for the Insole Condition, for both the right [Wilks' Lambda = 0.790, F(14, 492) = 4.393, p < 0.01, partial eta squared = 0.111] and left feet [Wilks' Lambda = 0.890, F(14, 492) = 2.103, p < 0.011, partial eta squared = 0.056]. The 2.5 mm-tall dimple insole was shown to be significantly more effective at reducing the temperature in the hallux and third met head regions compared to the 4 mm-tall dimple insole. The insoles showed to be significantly more effective in the diabetes group versus the healthy group, with large effect size for the right [Wilks' Lambda = 0.662, F(14, 492) = 8.037, p < 0.000, Partial eta-squared = 0.186] and left feet [Wilks' Lambda = 0.739, F(14, 492) = 5.727, p < 0.000, Partial eta-squared = 0.140]. This can have important practical implications for designing insoles with a view to decrease foot complications in people with diabetes.

Effects of meridian sinew tuina after identifying the treatment area under ultrasound localization combined with greater and third occipital nerve injections in cervicogenic headache: a randomized controlled trial protocol.

Introduction: Cervicogenic headache (CEH) is a secondary headache characterized by chronic, unilateral headache. Ultrasound-guided injections of the greater occipital nerve (GON) and the third occipital nerve (TON) are effective in the treatment of CEH, as is meridian sinew tuina for the treatment of CEH, but the evidence of clinical efficacy of combining these two therapies is valid. Therefore, we have designed a randomized controlled trial with the aim of investigating the efficacy and safety of ultrasound localization meridian sinew tuina combined with GON and TON injections for the treatment of CEH. Methods and analysis: In this study, we enroll 60 patients experiencing CEH. The control group receives ultrasound-guided injections of GON and TON. The intervention group is treated with ultrasound localization meridian sinew tuina combined with the injection of GON and TON. Meridian sinew tuina is performed once a day for 30 min for 3 days. The primary observational index includes the Short-Form of McGill Pain Questionnaire (SF-MPQ). The Secondary outcomes include Cervical Range of Motion (ROM) and Medical Infrared Thermography (MIT). MIT is used to measure the change in skin temperature in the area of the patient's meridian sinew tuina treatment of GON and TON before and after the intervention. There are 5 time points assessed as baseline, day 3, day 15, day 30, and day 60. Discussion: This study proposes to combine ultrasound-guided injections of GON and TON for the treatment of CEH after identifying the treatment area of meridian sinew tuina under ultrasound localization. Meanwhile, MIT is utilized to provide objective evidence of the efficacy of CEH. Clinical trial registration: ChiCTR2300076128.

Evaluation of the scrotal thermal environment and the testicular sizes in prepubertal hemiscrotal agenesis without cryptorchidism.

Introduction: Hemiscrotal agenesis is a rare scrotal developmental disorder. Orchiopexy on the opposite side of the scrotum with rugae or scrotoplasty combined with orchiopexy is usually performed as a surgical treatment for hemiscrotal agenesis with cryptorchidism. Till date, there are only eight published case studies of hemiscrotal agenesis. Case presentation: A 6-year-old boy, who had been previously treated for infantile hemangiomas, was referred by a pediatrician to our hospital for the follow-up of hemiscrotal agenesis without cryptorchidism. Thermography demonstrated that the temperature of the right scrotal skin with no rugae was higher than that of the left scrotal skin with rugae. The patient's parent declined scrotoplasty because the hemiscrotal agenesis was to be followed up without scrotoplasty and scrotal ultrasonography revealed no abnormal findings in both testes. Conclusion: High-temperature environment may not impair the testicular growth in prepubertal hemiscrotal agenesis without cryptorchidism.