Application Of Infrared Thermography Research Articles

Uses of infrared thermography in acute illness: a systematic review.

Infrared thermography (IRT) is a non-contact, non-ionising imaging modality, providing a visual representation of temperature distribution across a surface. We conducted a systematic search of indexed and grey literature for studies investigating IRT applications involving patients in acute care settings. Studies were categorised and described along themes identified iteratively using narrative synthesis. Quality appraisal of included studies was performed using the Quality Assessment tool for Diagnostic Accuracy Studies. Of 1,060 unique records, 30 studies were included. These were conducted in emergency departments and intensive care units involving adult, paediatric and neonatal patients. IRT was studied for the diagnosis, monitoring or risk stratification of a wide range of individual conditions. IRT was predominantly used to display thermal change associated with localised inflammation or microcirculatory dysfunction. Existing research is largely at an early developmental stage. We recommend that high quality diagnostic validation studies are now required for some clinical applications. IRT has the potential to be a valuable tool in the acute care setting and represents an important area for future research particularly when combined with advances in machine learning technology. CRD 42022327619 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=327619).

Swin transformer network leveraging multi-dimensional features for defect depth prediction

This study introduces a novel method for accurately predicting defect depth in pulsed infrared thermography. The core innovation of this study lies in the utilization of multi-dimensional features to enhance the accuracy of depth prediction. By integrating temperature, temperature change rate, and time-frequency spectrum into a comprehensive feature set, we aim to capture a more detailed understanding of defect characteristics, thereby facilitating more precise predictions. Additionally, we employ the Hilbert encoding method to obtain two-dimensional matrices and utilize mask-based augmentation to generate synthetic defect data matrices. Subsequently, the generated matrices are fed input into a Swin transformer network configured with shifted windows and multi-head self-attention. In comparison to existing high-performing architectures, our method leveraging multi-dimensional features, demonstrates superior performance, especially in defect depth prediction for non-planar samples. This work paves the way for more accurate and efficient defect depth prediction in various infrared thermography applications.

Application of Infrared Thermography in the Rehabilitation of Patients in Veterinary Medicine.

Infrared Thermography (IRT) has become an assistance tool in medicine and is used to noninvasively evaluate heat elimination during and after inflammatory processes or during the recovery period. However, its application in veterinary patients undergoing physiotherapy is a field that requires deep research. This review aims to analyze the application of IRT in the monitoring of animal physiotherapy, using the thermal changes that are present in patients undergoing gait or lameness issues (e.g., inflammation, pain, increased local temperature) as a neurobiological basis. Rehabilitation techniques such as acupuncture, physical therapies, thermotherapy, photo-biomodulation, and electrostimulation have been reported to have an anti-inflammatory effect that decreases the amount of local heat production, which is heat that can be recorded with IRT. Therefore, IRT could be used as a complementary tool to evaluate the effectiveness of the therapy, and it is suggested that further studies evaluate the accuracy, sensibility, and sensitivity of IRT.

Thermal imaging and computer vision technologies for the enhancement of pig husbandry: a review.

Pig farming, a vital industry, necessitates proactive measures for early disease detection and crush symptom monitoring to ensure optimum pig health and safety. This review explores advanced thermal sensing technologies and computer vision-based thermal imaging techniques employed for pig disease and piglet crush symptom monitoring on pig farms. Infrared thermography (IRT) is a non-invasive and efficient technology for measuring pig body temperature, providing advantages such as non-destructive, long-distance, and high-sensitivity measurements. Unlike traditional methods, IRT offers a quick and labor-saving approach to acquiring physiological data impacted by environmental temperature, crucial for understanding pig body physiology and metabolism. IRT aids in early disease detection, respiratory health monitoring, and evaluating vaccination effectiveness. Challenges include body surface emissivity variations affecting measurement accuracy. Thermal imaging and deep learning algorithms are used for pig behavior recognition, with the dorsal plane effective for stress detection. Remote health monitoring through thermal imaging, deep learning, and wearable devices facilitates non-invasive assessment of pig health, minimizing medication use. Integration of advanced sensors, thermal imaging, and deep learning shows potential for disease detection and improvement in pig farming, but challenges and ethical considerations must be addressed for successful implementation. This review summarizes the state-of-the-art technologies used in the pig farming industry, including computer vision algorithms such as object detection, image segmentation, and deep learning techniques. It also discusses the benefits and limitations of IRT technology, providing an overview of the current research field. This study provides valuable insights for researchers and farmers regarding IRT application in pig production, highlighting notable approaches and the latest research findings in this field.

Thermal Imaging as a Method to Indirectly Assess Peripheral Vascular Integrity and Tissue Viability in Veterinary Medicine: Animal Models and Clinical Applications.

Infrared thermography (IRT) is a technique that indirectly assesses peripheral blood circulation and its resulting amount of radiated heat. Due to these properties, thermal imaging is currently applied in human medicine to noninvasively evaluate peripheral vascular disorders such as thrombosis, thromboembolisms, and other ischemic processes. Moreover, tissular damage (e.g., burn injuries) also causes microvasculature compromise. Therefore, thermography can be applied to determine the degree of damage according to the viability of tissues and blood vessels, and it can also be used as a technique to monitor skin transplant procedures such as grafting and free flaps. The present review aims to summarize and analyze the application of IRT in veterinary medicine as a method to indirectly assess peripheral vascular integrity and its relation to the amount of radiated heat and as a diagnostic technique for tissue viability, degree of damage, and wound care.

Infrared thermography application for in-situ determination of the building envelope thermal performance

During the phase of creating energy audit documentation, many calculations are needed when evaluating the thermal performance of building envelope components due to a large number of distinct components and junctions. Several computer programs are available to assess buildings’ energy consumption, using the thermal performance of building envelope elements as input data. These thermal performances are often provided with varying degrees of accuracy, typically only for the current field of the component, without considering the impact of thermal bridges. However, when using linear heat transfer coefficients ψ, the details provided in thermal bridges’ atlases do not cover all the case studies encountered in the current design, which often requires approximate details. In some cases, the technical documentation of the building is unavailable, which leads to various assumptions about the detailing of the building envelope and a non-realistic picture of the energy performance of the assessed building. The paper presents a methodology and accompanying software called THERMOG that evaluates the thermal performance of the building envelope under actual operating conditions using aerial and terrestrial thermography methods. The paper presents initial findings from some case studies used to calibrate the developed methodology.

Innovations in Building Diagnostics and Condition Monitoring: A Comprehensive Review of Infrared Thermography Applications

Infrared thermography is a non-destructive technique that uses infrared radiation to visualize surface temperature variations. It is a versatile tool that can be used to detect a variety of problems in buildings, including insulation deficiencies, moisture intrusion, structural compromise, and electrical faults. The review paper discusses the fundamental principles of infrared thermography, the different types of infrared approaches, and the condition monitoring of buildings using infrared imaging techniques. It also discusses research showing how infrared thermography has been applied to recognize and solve different building-related problems. The article highlights the potential for infrared thermography to advance while also acknowledging its current limits. Infrared thermography is predicted to become an even more effective technique for building diagnostics with the development of more sensitive cameras and the incorporation of artificial intelligence.

Use of infrared thermography from a crewed aerial vehicle for remote sensing of tropical pasture areas with different levels of afforestation

Better livestock practices are needed to enable more efficient and sustainable food production. Integrated crop-livestock-forest (iCLF) production systems stand out among these. However, iCLF systems have not yet been monitored remotely using infrared thermography (IRT). Crewed overflights were conducted every 21 days for 14 months in São Carlos, Brazil (21°58′30″S, 47°51′07″W, 854 m AMSL) to (i) evaluate the efficiency of remote thermographic sensing of pastures for beef cattle and (ii) study the surface temperatures of pastures in monoculture/full sun (FS system) or iCLF (iCLF system). There was a significant correlation between air temperatures recorded at 1.5 m from the ground by automated meteorological stations and temperatures recorded using IRT, with the highest correlation coefficients observed in FS at 12:00 PM (r = 0.89; P = 0.0013) and in iCLF between 10:00 AM and 11:00 AM (r = 0.77; P = 0.0142). The surface and air temperatures did not differ significantly in FS (2:00 PM–4:00 PM) and iCLF (8:00 AM–6:00 PM; P > 0.05). In all seasons, IRT revealed higher thermal classes more frequently in FS. Heat maps showed notable differences between the production systems, including two heterogeneous thermal zones. Circumscribed areas of varying sizes with higher surface temperatures (>35.0 °C) were also observed in spots (FS) or parallel bands in the east–west direction (iCLF). These areas had no trees and/or less vegetation cover. Infrared thermography remote sensing in crewed overflights ran concurrently with temperature readings from on-site meteorological stations. This enabled the precise identification of thermographic differences between pastures in monoculture and integrated systems, with the definition of heat islands and comfort zones. This study provides insights into the novel application of IRT for microclimatic assessments of livestock pastures, which can aid in decision-making to improve the welfare of free-range animals.

InfraRed Thermography and 3D-Data Fusion for Architectural Heritage: A Scoping Review

Comprehensive documentation is the foundation of effective conservation, repair and maintenance (CRM) practices for architectural heritage. In order to diagnose historic buildings and inform decision making, a combination of multi-disciplinary surveys is fundamental to understanding a building’s heritage and performance. Infrared thermography (IRT), a non-contact, non-invasive and non-destructive imaging technique, allows both qualitative and quantitative assessments of temperature to be undertaken. However, the inherent low spatial resolution of thermal imaging has led recent work to fuse thermographic and geometric data for the accurate 3D documentation of architectural heritage. This paper maps the scope of this emerging field to understand the application of IRT and 3D-data fusion (IRT-3DDF) for architectural heritage. A scoping review is undertaken to systematically map the current literature and determine research gaps and future trends. Results indicate that the increasing availability of thermal cameras and advances in photogrammetric software are enabling thermal models to be generated successfully for the diagnosis and holistic management of architectural heritage. In addition, it is evident that IRT-3DDF provides several opportunities for additional data integration, historic building information modelling (H-BIM) and temporal analysis of historic buildings. Future developments are needed to transform IRT-3DDF findings into actionable insights and to apply IRT-3DDF to pressing climate-related challenges, such as energy efficiency, retrofitting and thermal comfort assessments.

Applications of Infrared Thermography in Ophthalmology

Body temperature is one of the key vital signs for determining a disease's severity, as it reflects the thermal energy generated by an individual's metabolism. Since the first study on the relationship between body temperature and diseases by Carl Reinhold August Wunderlich at the end of the 19th century, various forms of thermometers have been developed to measure body temperature. Traditionally, methods for measuring temperature can be invasive, semi-invasive, and non-invasive. In recent years, great technological advances have reduced the cost of thermographic cameras, which allowed extending their use. Thermal cameras capture the infrared radiation of the electromagnetic spectrum and process the images to represent the temperature of the object under study through a range of colors, where each color and its hue indicate a previously established temperature. Currently, cameras have a sensitivity that allows them to detect changes in temperature as small as 0.01 °C. Along with its use in other areas of medicine, thermography has been used at the ocular level for more than 50 years. In healthy subjects, the literature reports that the average corneal temperature ranges from 32.9 to 36 °C. One of the possible sources of variability in normal values is age, and other possible sources of variation are gender and external temperature. In addition to the evaluation of healthy subjects, thermography has been used to evaluate its usefulness in various eye diseases, such as Graves' orbitopathy, and tear duct obstruction for orbital diseases. The ocular surface is the most studied area. Ocular surface temperature is influenced by multiple conditions, one of the most studied being dry eye; other diseases studied include allergic conjunctivitis and pterygium as well as systemic diseases such as carotid artery stenosis. Among the corneal diseases studied are keratoconus, infectious keratitis, corneal graft rejection, the use of scleral or soft contact lenses, and the response to refractive or cataract surgery. Other diseases where thermographic features have been reported are glaucoma, diabetic retinopathy, age-related macular degeneration, retinal vascular occlusions, intraocular tumors as well as scleritis, and other inflammatory eye diseases.

Characterization of high-temperature paints for infrared thermography in fire research

Infrared temperature measurements are common in fire research and adjacent fields to provide spatially-resolved temperature distributions on surfaces. To obtain accurate temperature values from these instruments, a well-characterized emissive surface is desired to minimize error in the calculated values. In fire applications, the robustness of the surface coating is also an important consideration. To this end, surfaces to be measured with infrared thermal cameras are commonly coated with a high-emissivity coating to reduce uncertainty in measurements. Here, the optical properties and thermal stability of a set of commercially available paints were characterized to assess their suitability for future applications and to provide a reference dataset for researchers. The thermal stability of the paints was assessed using thermogravimetry to measure degradation at elevated temperatures. Emissivity was determined spectrally at room temperature and as a band-averaged value as a function of temperature for long-wave infrared thermography applications. Differences were revealed in these tests, indicating a need to carefully select coatings based on the application, giving consideration to the exposure temperature, optical-sensing band, and dynamic emissivity input for temperature-varying environments. Properties collected were verified against a bench-scale experiment with flame exposure, demonstrating the accuracy and usefulness of infrared thermography in fire research applications.

Infrared Thermography Compared to Standard Care in the Prevention and Care of Diabetic Foot: A Cost Analysis Utilizing Real-World Data and an Expert Panel.

Infrared thermography (IRT) is a non-invasive technology for screening and early detection of diabetic foot. Real-world data and the Delphi technique were used to assess IRT's potential effect on typical care pathways of diabetic foot and their costs in the Finnish healthcare setting. The most typical care pathways of diabetic foot were identified from national healthcare registers from 2011 to 2017. The effect of IRT in terms of avoidable care episodes was assessed by a Delphi panel including Finnish diabetic foot specialists (n=13). By combining a series of decision-analytic models, the IRT's potential effect on the costs of each pathway and their sensitivity to model assumptions were estimated. Hypothetical annual savings were estimated to be EUR ~1.7 million (EUR ~1.3 million-EUR ~2.5 million), constituting approximately 20% of the total annual care pathway costs examined. In the longer and more complex pathways, the application of IRT was estimated to result in notable savings while in the shorter pathways, IRT could increase costs. Our modeling suggests that IRT could potentially reduce costs in a Finnish healthcare setting. Given our analysis, generation of robust evidence on the effectiveness of recent IRT technologies with up-to-date protocols seems appropriate.

A Review of Fault Diagnosis Methods for Rotating Machinery Using Infrared Thermography.

At present, rotating machinery is widely used in all walks of life and has become the key equipment in many production processes. It is of great significance to strengthen the condition monitoring of rotating machinery, timely diagnose and eliminate faults to ensure the safe and efficient operation of rotating machinery and improve the economic benefits of enterprises. When the state of a rotating machine deteriorates, the thermal energy that is much more than its normal operation will be generated due to the increase in the friction between the components or other factors. Therefore, using the infrared thermal camera to collect the infrared thermal images of rotating machinery and judge the health status of rotating machinery by observing the temperature distribution in the thermal images is often more rapid and effective than other technologies. Nevertheless, after decades of development, the research achievements of infrared thermography (IRT) and its application in various industrial fields are numerous and complex, and there is a lack of systematic sorting and summary of the achievements in this field. Accordingly, this paper summarizes the development and application of IRT as a non-contact and non-invasive tool for equipment condition monitoring and fault diagnosis, and introduces the basic theory of IRT, image processing technology and fault diagnosis methods of rotating machinery in detail. Finally, the review is summarized and some future potential topics are proposed, which will make the subject easier for beginners and non-experts to understand.

A Preliminary Study on Infrared Thermograph of Metabolic Syndrome.

ObjectiveTo explore the temperature distribution characteristics of the face, palms, feet and the trunk area of metabolic syndrome (MS) through infrared thermography (IRT) and provide evidence for the application of IRT in the assistant evaluation of MS population.MethodsWe collected thermographs of 184 participants (91 males, 93 females) and further divided participants of each gender into 4 groups according to the number of abnormal metabolic indexes. Mean temperatures of 6 Region of Interests (ROIs) (face, anterior trunk, bilateral palms and dorsum of feet) were calculated. Comparisons of the mean temperatures between genders, among groups and ROIs were carried out.ResultsMale participants had higher mean temperature in their face, palms (P<0.01) and dorsum of feet (P<0.05), and lower mean temperature in the anterior trunk (P<0.01). Female participants with MS had higher mean temperature in their palms and dorsum of feet (P<0.01) and lower mean temperature in the anterior trunk (P<0.01) than normal participants. Similar tendencies were shown in the mean temperature of the left palms and trunk of MS males. With the increase of the number of abnormal metabolic indexes, it seems that the mean temperature gradually increased in palms and dorsum of feet, and decreased in the anterior trunk.ConclusionThe thermograph of MS exhibits certain characteristics. This may help reveal the correlations between Infrared thermography and metabolic disorders.

Clinical applicability of infrared thermography in rheumatic diseases: A systematic review.

Rheumatic Diseases (RD) are a class of disorders of the musculoskeletal system, including different conditions, and are considered a major cause of disability among the population. RD do not have an objective and quick diagnosis and are sometimes challenging. In this way, Infrared Thermography (IT) could represent a fast and effective tool to detect essential information for diagnosing RD. Thus, the aim of this systematic review was to summarize and describe the clinical applicability of IT in RD. This innovative systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in the International Prospective Registry of Systematic Reviews (PROSPERO) (CRD42020214601). The risk of bias assessment was performed using the Cochrane tool. The PubMed, EMBASE, Science Direct, Web of Science, CINAHL, and SciELO databases were searched from their inception to June 2021. In total, 476 studies were identified and 12 studies met the inclusion criteria. The main RD analyzed were Raynaud's Phenomenon (RP), Scleroderma, Osteoarthritis (OA), Rheumatoid arthritis (RA), and localized juvenile scleroderma. The assessment protocols were similar in terms of acclimatization time, distance between the camera and the individual, temperature, and ambient humidity. Evidence demonstrates that infrared thermography is an effective tool to assess the health status of individuals with rheumatic diseases, producing clinical information relevant to diagnosis and treatment.

In situ Passive Infrared Thermography Application for the Assessment of Localized Mechanical Properties of Tungsten Inert Gas-Welded Inconel 625 Alloys

In situ Passive Infrared Thermography Application for the Assessment of Localized Mechanical Properties of Tungsten Inert Gas-Welded Inconel 625 Alloys

Investigating the thermal physiology of Critically Endangered North Atlantic right whales Eubalaena glacialis via aerial infrared thermography

The Critically Endangered status of North Atlantic right whalesEubalaena glacialis(NARWs) warrants the development of new, less invasive technology to monitor the health of individuals. Combined with advancements in remotely piloted aircraft systems (RPAS, commonly ‘drones’), infrared thermography (IRT) is being increasingly used to detect and count marine mammals and study their physiology. We conducted RPAS-based IRT over NARWs in Cape Cod Bay, MA, USA, in 2017 and 2018. Observations demonstrated 3 particularly useful applications of RPAS-based IRT to study large whales: (1) exploring patterns of cranial heat loss and providing insight into the physiological mechanisms that produce these patterns; (2) tracking subsurface individuals in real-time (depending on the thermal stratification of the water column) using cold surface water anomalies resulting from fluke upstrokes; and (3) detecting natural changes in superficial blood circulation or diagnosing pathology based on heat anomalies on post-cranial body surfaces. These qualitative applications present a new, important opportunity to study, monitor, and conserve large whales, particularly rare and at-risk species such as NARWs. Despite the challenges of using this technology in aquatic environments, the applications of RPAS-based IRT for monitoring the health and behavior of endangered marine mammals, including the collection of quantitative data on thermal physiology, will continue to diversify.

Principles and cautions in the infrared thermography application in sheep

Infrared thermography is a safe technology for diagnostic imaging that preserves welfare and does not emit ionizing radiation. This paper aimed to report the principles of infrared thermography formation and cautions on imaging acquisition with sheep illustrations. This technique is based on capturing infrared electromagnetic energy from the matter molecules, proportional to the increase in temperature. The capture of images, not just in sheep, must obey technical criteria to avoid interpretation errors of the thermograms. Direct exposure to solar radiation, humidity, manipulation of the examined area, time of day, proper use of equipment, and the manifestation of certain behaviors can hinder the interpretation of the findings. Infrared thermography is a tool that helps practitioners because it provides practicality, safety, and accurate data.

ESTIMATION OF RECTAL TEMPERATURE OF GOATS BASED ON SURFACE TEMPERATURE

Infrared thermography (IR) is a non-invasive tool with potential to indicate changes in the animal’s thermal conditions in response to the thermally stressful environment. The objective of this study was to evaluate the application of IR to estimate the rectal temperature of crossbred goats of the Boer breed. Six male crossbred goats of the Boer breed were distributed in a completely randomized design and submitted to temperatures of 26, 30 and 34 °C. Rectal temperature (RT) and thermograms data were collected from animals at each air temperature evaluated. In the thermograms, the temperatures of the ocular globe (PT), head (HT), shoulder (ST), hindquarter (HQ) and maximum infrared (IRMax) of the animals’ surfaces were collected, the latter being observed in the lower region of the animals’ eyes, at all air temperatures evaluated. The correlation of PT, HT, ST, HQ and IRMax data with the RT was evaluated through the Pearson coefficient analysis and the concordance using Bland-Altman diagrams. With the exception of the IRMax surface temperature, the others were adequate for the accurate estimation of RT, with PT standing out for presenting the highest correlation coefficient with RT (r = 0.951) and estimation errors varying in the range of ± 0.27 °C.

Infrared thermography analysis with a low-cost camera in plaster sculptures of museum collections

Infrared thermography (IRT) is a non-destructive and non-invasive technique that provides the possibility to investigate the surface of sculptures for the detection of subsurface features and anomalies such as delamination, layer structure, fillings, and defects. IRT has been widely used in buildings and large structures, as well as in works of art such as bronze sculptures and paintings. This article describes the application of active infrared thermography, using a portable low-cost IRT camera, in the examination of plaster sculptures, a material where it has not yet been applied to. In particular, it was used in two plaster sculptures by 19th-century Portuguese artist Soares dos Reis, within a wider project (GEO-SR) aimed at the study of his work. The results indicate that thermography is a suitable technique with a great potential to detect alterations under the surface of plaster, revealing a new look into its manufacturing and conservation.