Infrared thermography in metabolic diseases

The prevalence of metabolic diseases,some diseases that are seriously harmful for human health and affect the quality of life,is increasing year by year.Early detection and intervention is the common strategy to deal with them.Infrared thermography(IRT)is a special medical imaging technology which can capture the changes of skin temperature associated with metabolic disorders.It might be a new method for early detection of metabolic diseases.The purpose of this review is to summarize advances of the use of IRT in evaluating single metabolic disorder such as obesity,hyperglycemia and hypertension,complex metabolic disorders such as metabolic syndrome and target organ damage such as coronary artery atherosclerosis and diabetic foot.The characteristic of thermograms of metabolic disease patients,the changes of thermal maps during the development of the disease,and the lacks in current studies are also discussed in the article.

Anisotropy of Fatigue Behavior and Tensile Behavior of 5A06 Aluminum Alloy Based on Infrared Thermography

The fatigue behavior during high cycle fatigue testing and the tensile behavior of 5A06 aluminum alloy considering the anisotropy were studied.Two types of specimens including longitudinal specimen（parallel to the rolling direction） and transverse specimen（perpendicular to the rolling direction） were prepared.Infrared thermography was employed to monitor the temperature evolution during the fatigue and tensile tests.The temperature evolution curves in the two directions were contrastively analyzed.It is found that the temperature evolution during fatigue process possesses four stages：initial temperature rise stage,slow temperature decline stage,rapid temperature rise stage,and finial temperature decline stage.The heat generating mechanisms of the four stages are discussed.Obvious differences can be found between the longitudinal specimen and transverse specimen in fatigue strength and fatigue life.The fatigue strength and fatigue life of longitudinal specimen are higher than those of transverse specimen.During the tensile and fatigue testing process,the fracture temperature in the transverse direction are higher than that in the longitudinal direction.The fatigue strength prediction by means of infrared thermography has a good consistency with that by the traditional method.

Counting Method of Mangrove Pests Based on Infrared Thermography

In the field of plant protection,certain methods for assessing the current pest situation and implementing appropriate protection countermeasures can effectively protect plants while saving manpower and material resources.However,current pest monitoring methods are primarily based on the stage of"seeing,hand checking,disc shooting and net catching",and the level of automation is low.Manual methods are time-consuming,prone to error,and difficult to review.We designed a method based on infrared thermography principle for counting Ricania guttata(Walker),a pest which is harmful to mangrove plants.This method,which is based on thermal infrared images and binarized image segmentation,realizes image processing of surface temperature,effectively distinguishes pests and sticky board,automatically counts the number of pests,and expands the data source based on image processing.Furthermore,this method contributes to the solution of the problem that counting error of insect close to the color of sticky board is greater in image recognition of visible light,when the pest color is close to the stick board.It can facilitate manual investigation of mangrove pests,simply and efficiently count the number of pests on the stick board,and provide data and technical support for pest condition analysis and control.

Study on divertor heat flux under n=3 and n=4 resonant magnetic perturbations using infrared thermography diagnostic in EAST

Resonant magnetic perturbations(RMPs)with high toroidal mode number n are considered for controlling edge-localized modes(ELMs)and divertor heat flux in future ITER H-mode operations.In this paper,characteristics of divertor heat flux under high-nRMPs(n=3 and 4)in H-mode plasma are investigated using newly upgraded infrared thermography diagnostic in EAST.Additional splitting strike point(SSP)accompanying with ELM suppression is observed under both RMPs with n=3 and n=4,the SSP in heat flux profile agrees qualitatively with the modeled magnetic footprint.Although RMPs suppress ELMs,they increase the stationary heat flux during ELM suppression.The dependence of heat flux on q_(95)during ELM suppression is preliminarily investigated,and further splitting in the original strike point is observed at q 495=during ELM suppression.In terms of ELM pulses,the presence of RMPs shows little influence on transient heat flux distribution.

Laser Heating and Infrared Thermography of Building Materials

In this work, a 532 nm diode CW laser is used to heat samples used as building materials at a 1 meter standoff distance while using an FLIR (Forward-Looking Infrared) thermal camera to monitor and record the heating and then cooling of each sample after lasers are switched off. The data is then analyzed using FLIR proprietary software. Since the absorption spectra of materials are unique, using multiple lasers of different wavelengths to simultaneously shine onto the sample at different locations would give enough thermal data to successfully characterize the samples within a reasonable amount of time. The results are very promising for applications involving non-destructive detection and classification of materials.

Value of knee skin temperature measured by infrared thermography and soluble intercellular adhesion molecule-1 in the diagnosis of peri-prosthetic knee infection in Chinese individuals following total knee arthroplasty

Background Total knee arthroplasty （TKA） is a successful and frequently performed procedure in orthopedic surgery.The diagnosis of peri-prosthetic joint infection following TKA remains challenging.The present study estimated the usefulness of knee skin temperature （measured by infrared thermography） and serum soluble intercellular adhesion molecule-1 （slCAM-1） in the diagnosis of post-operative knee peri-prosthetic infection.Methods Patients were divided into three groups：21 patients undergoing uncomplicated TKAs,seven with prosthesis infection,and three undergoing TKA revisions.The serum levels of interleukin-6 （IL-6）,C-reactive protein （CRP）,erythrocyte sedimentation rate （ESR）,and slCAM-1 as well as the local knee skin temperature were measured preoperatively and on Days 1 and 7 and at 1,3,and 6 months post-operatively in Groups 1 and 3.The same parameters were measured in Group 2 at the time of prosthesis infection diagnosis.Results In Group 1,the levels of IL-6,CRP,ESR,and knee skin temperature were significantly elevated post-operatively,but returned to baseline levels within 6 months.The slCAM-1 levels were not significantly different.The mean differential temperature （MDT） and levels of siCAM-1,IL-6,CRP,and ESR differed significantly between Groups 1 and 2.The MDT had returned to normal in Group 3 by 6 months post-operatively.Conclusions Elevations in IL-6,CRP,ESR,and MDT in patients undergoing TKA could be a normal response to surgical trauma,but sustained elevations may be indicative of complications.The knee skin temperature and slCAM-1 may be used as indicators in the diagnosis of knee prosthesis infection following TKA.

Diagnostic Significance of Topical Image of Infrared Thermography on The Patients with Lumbar Intervertebral Disc Protrusion AComparative Study on 45 Patients with Manipulative Treatment and 65 Normal Control

Objective: To analyse and explore the diagnostic significance of infrared thermography on the patients with lumbar intervertebral disc protrusion.Methods: Forty-five hospitalized cases under conservative treatment (mainly manipulation) and 65 controls were consecutively selected. Both groups were examined with infrared thermography on lower back and lower extremities as well as physical examination before and after treatment. The study statistically analysed the temperature difference between the involved and healthy parts at different areas; and also compared the variation of the temperature difference after the treatment to the decreasing scores of physical examination afterward. Results: The statistic result showed that the temperature difference between two sides on patient group was significantly higher than those of the control group. The further analysis showed that the temperature difference at posterior femur area in the patients’ group correlated significantly to the severity of clinical signs caused by nerve root irritation.Conclusion: The thermogram was uncertain to the segmental diagnosis of lumbar disc protrusion and could only be considered as a reference in the final diagnosis. Nevertheless, it is helpful to discover the severity of radical signs according to the posterior femoral region of hypo- (hyper-) thermogram.

Evaluation tool for the thermal performance of retrofitted buildings using an integrated approach of deep learning artificial neural networks and infrared thermography

In most countries,buildings are responsible for significant energy consumption where space heating and air conditioning is responsible for the majority of this energy use.To reduce this massive consumption and decrease carbon emission,thermal insulation of buildings can play an important role.The estimation of energy savings following the improvement of a building’s insulation remains a key area of research in order to calculate the cost savings and the payback period.In this paper,a case study has been presented where deep retrofitting has been introduced to an existing building to bring it closer to a Passivhaus standard with the introduction of insulation and solar photovoltaic panels.The thermal performance of the building with its improved insulation has been evaluated using infrared thermography.Artificial intelligence using deep learning neural networks is implemented to predict the thermal performance of the building and the expected energy savings.The prediction of neural networks is compared with the actual savings calculated using historical weather data.The results of the neural network show high accuracy of predicting the actual energy savings with success rate of about 82%when compared with the calculated values.The results show that this suggested approach can be used to rapidly predict energy savings from retrofitting of buildings with reasonable accuracy,hence providing a practical rapid tool for the building industry and communities to estimate energy savings.A mathematical model has been also developed which has indicated a life-long monitoring will be needed to precisely estimate the benefits of energy savings in retrofitting due to the change in weather conditions and people’s behaviour.

A building unit decomposition model for energy leakage by infrared thermography image analysis

A quantitative energy leakage model was developed based on the thermography image data measured for both external and internal building surfaces.The infrared thermography images of both surfaces of doors,windows,and walls of an office building in the Hengqin Campus of University of Macao were taken at various times in a day for four seasons.The transient heat flux for sample units were obtained based on measurements of the seasonal transient local temperature differences and calculations of the effective thermal conductivity from the multiple-layer porous medium conduction model.Effects of construction unit types,orientations,and seasons were quantitatively investigated with unit transient orientation index factors.The corresponding electric energy consumption was calculated based on the air conditioning system coefficient of performance of heat pump and refrigerator cycles for different seasons.The model was validated by comparing to the electric meter records of energy consumption of the air conditioning system.The uncertainties of the predicted total building energy leakage are about 14.7%,12.8%,12.4%,and 15.8%for the four seasons,respectively.The differences between the predicted electric consumption and meter values are less than 13.4%and 5.4%for summer and winter,respectively.The typical daily thermal energy leakage value in winter is the highest among the four seasons.However,the daily electric energy consumption by the air conditioning system in summer and autumn is higher than that in winter.The present decomposition model for energy leakage is expected to provide a practical tool for quantitative analysis of energy leakage of buildings.

A Preliminary Study on Evaluation of Electro-Acupunctural Effect by Using Cortical Infrared Thermography

Objective: To explore the possibility of using cortical infrared thermography (CIT) and temperature in studying the principle of acupuncture and moxibustion. Methods: The changes of the cerebral cortical temperature during electro-acupuncture (EA) measured by CIT in twenty cats were observed. By opening the skull before experiments, the cortex of animals was revealed. The distribution of the conical temperature of the awakened animals was studied by AGA infrared thermovision, and the thermograms were analysed by computer. Results: (1) The thermograms of the profile of the cortex could be displayed clearly, the temperature was higher in the ante and lower in post-cortex than that in other regions. (2) No tendency of conical temperature ascending within 30 minutes in cats without EA. (3 ) After EA, the temperature of cortex generally increased by 0.3 to 1.7 degrees centigrade, and 5 min after EA, the increment of temperature was the highest, 10 min after EA, the temperature increment was higher than before EA, but lower than 5 min after EA. The conical temperature recovered 10 min after stopping the stimulation. (4) The temperature increment was more obvious in the regions of ant. ectosylvian, ant. supra-Sylvian and ant. Sylvian than that in other regions. No matter where the site of EA was, every group had its own special region of higher temperature increment. Conclusion: The temperature increased in the cortex were mainly in the somatosensory regions. The extent and position of temperature response of cortex after EA could be displayed with CIT directly by picture. The display of the temperature response could be taken as the indication of the nervous activity. CIT could be used to conduct the studies of the acupuncture and the brain.

Numerical Simulation of Non-destructive Testing of Stainless Steel Composites Plate by Infrared Thermography

The non-destructive testing(NDT)of debonding in stainless steel composites plate(SSCP)is performed by infrared thermography,finite element analysis(FEA)software ANSYS is taken as the simulative tool,and 2D simulative model has been set up to investigate effect of the thickness of coating and/or substrate on the detectibility of debonging in SSCPs.Two parameters,namely the maximum defect temperature difference and defect appearing index,are defined to evaluate the detectivity of defects,and their computational methods and formulas are given respectively.The preliminary changing tendency of the maximum defect temperature difference and defect appearing index with the thickness of coating and/or substrate is found by numerical simulation.

The Influence of Age on Blood Flow and Temperature of Acupuncture Points: A Study based on Laser Doppler Flowmetry and Infrared Thermography

Background:To date,there has been a great lack of investigation on the influence of age on blood flow and temperature of acupoints in specific regions.Objective:This study aimed to determine the association between different age categories and acupoint blood flow/temperature on the forearm.Methods:Acupoint blood flow and temperature were measured in healthy adults of different age categories using laser doppler flowmetry(LDF)and infrared thermography(IRT),respectively.A total of 60 eligible healthy volunteers were divided into the young group,mid age group and old age group.All groups received LDF and IRT examination.Shenmen(HT7),Shaohai(HT3),Taiyuan(LU9)and Chize(LU5)of the Heart and Lung meridians on the forearm were selected as 4 test acupoints.Results:Regarding blood flow of the 4 test acupoints,the PU of Taiyuan(LU9)in the old age group was sig-nificantly different compared with that of the young age group(P<0.05)and the mid age group(P<0.05),while there was no significant difference in PU of the other acupoints between 3 groups(all P>0.05).Simi-larly,regarding acupoint temperature of the 4 test sites,the temperature of Shaohai(HT3)in the old age group was significantly different compared with that of the mid age group(P<0.05),while there was no significant difference in the temperature of the other 3 acupoints between 3 age groups(all P>0.05).Conclusion:Age category tends to have notable influence on the blood flow and temperature in specific acupoints in the forearm.Therefore,particular concerns should be taken into consideration regarding the effect of age differences for future studies in this field.Nevertheless,further studies with a large sample size and more test acupoints are needed to further verify current findings.

An innovative approach towards enhancing energy conservation in buildings via public engagement using DIY infrared thermography surveys

Energy consumption in urban environment in the EU accounts for about 40%of the total energy consumption,and the majority of this energy is utilised for heating and air conditioning of buildings.Hence the process of insulating and retrofitting of relatively old buildings is essential to enhance the thermal performance and hence contribute to energy and carbon emission reduction.There is a need to enhance people’s engagement and education in relation to such issues to inspire and encourage positive actions and investment from the public.This paper presents an approach of combining a novel training process using a low-cost infrared thermal camera with small scale building model to promote DIY(Do-It-Yourself)infrared survey for the public to evaluate the performance of their own homes in order to identify any issues related to insulation or air leaks from the building envelop to encourage them to take corrective actions.The work included the engagement of 50 people to survey their own homes to capture the technical findings as well as their personal reaction and feedback.The results show that 88%of participants have found the educational session helpful to understand the infrared thermography;and 92%have considered the infrared camera to be an effective tool to indicate location of heat losses.Additionally,90%of participants trust that the thermal camera has helped them to identify insulation defects that cause heat losses in their homes.Moreover,84%believe that the thermal imaging has convinced them to think more seriously about the heat losses of their homes and what they could do to improve that.The experimental thermography surveys have shown that many houses have limitations in terms of thermal insulation which have been identified by the participants.This DIY interaction has provided enhanced public engagement and energy awareness via the use of the technology.The financial issues are also found to be critical,as none of the participants would have done the survey if they had to pay for it.Hence,this paper provides a solution for households with limited budgets.

Remote sensing of bark beetle damage in Norway spruce individual tree canopies using thermal infrared and airborne laser scanning data fusion

Background:Increasing threat to Central Europe’s forests from the growing population of the European spruce bark beetle Ips typographus (L.) calls for developing highly effective methods of detection of the infestation spots. The main goal of this study was to establish an automatic workflow for detection of dead trees and trees in poor condition of Picea abies using Middle Wave Infrared spectral range obtained from the aircraft.Methods:The studies were conducted in Wigry National Park (Poland) in 2020. A fusion of aircraft thermal data and laser scanning was used. Synchronous with thermal data acquisition ground reference data were obtained for P. abies in different health conditions. Determination of the range of canopy temperatures characteristic of the three condition states (‘healthy’,‘poor condition’,‘dead’) was performed using K-mean clustering. The accuracy of the method was evaluated on two validation sets:(1) individual tree canopies determined by photointerpretation, and (2) automatic segmentation of laser scanning data.Results:The results showed that the average temperature of ‘healthy’trees was 27.70℃, trees in ‘poor condition’28.57℃, and ‘dead’trees 30.17℃. High temperature differences between ‘healthy’and ‘dead’P. abies made it possible to distinguish these two condition classes with high accuracy. Lower accuracies were obtained for the class of ‘poor condition’, which was found to be confusing with both ‘healthy’and ‘dead’trees. According to results from the first validation set, a high overall accuracy of 0.60 was obtained. For the second validation set, the overall accuracy was reduced by 11%.Conclusions:This study indicates that canopy temperature recorded from the airborne level is a variable that differentiates ‘healthy’spruces from those in ‘poor condition’and the ‘dead’trees. The results confirmed that thermal and airborne laser scanning data fusion allows for creating a quick and simple workflow, which can successfully separate individual tree canopies and identify P. abies attacked by I. typographus. Further research is needed to identify trees in the early stages of invasion.

Benchmarking dynamic properties of structures using non-contact sensing

Non-contact sensing can be a rapid and convenient alternative for determining structure response compared to conventional instrumentation.Computer vision has been broadly implemented to enable accurate non-contact dynamic response measurements for structures.This study has analyzed the effect of non-contact sensors,including type,frame rate,and data collection platform,on the performance of a novel motion detection technique.Video recordings of a cantilever column were collected using a high-speed camera mounted on a tripod and an unmanned aerial system(UAS)equipped with visual and thermal sensors.The test specimen was subjected to an initial deformation and released.Specimen acceleration data were collected using an accelerometer installed on the cantilever end.The displacement from each non-contact sensor and the acceleration from the contact sensor were analyzed to measure the specimen′s natural frequency and damping ratio.The specimen′s first fundamental frequency and damping ratio results were validated by analyzing acceleration data from the top of the specimen and a finite element model.

A novel rock bolting system exploiting steel particles

The effectiveness of rock bolting in ground control has been extensively investigated,mainly for resin based systems.Alternative coupling materials are needed to have good mechanical performance and to reduce the economic impact.This study proposed a new bolting system exploiting steel particles as coupling material.The applicability of this system was assessed by laboratory and field pullout tests,assisted by digital imaging correlation(DIC),infrared thermography(IRT)and acoustic emission(AE).The results indicated that,for a 20 mm diameter bolt,the suitable steel particle size and corresponding inner diameter of borehole were 1.4 and 28 mm,respectively.For bolts installed in steel tubes,the particles improved the loading capacity compared to the resin bonded ones.Additional pullout tests on cement blocks indicated that steel particles can be effective for hard rock,whilst resin was a better choice for bolting of soft rock.Similar understanding was obtained by pullout tests in engineering fields,which demonstrated that the steel particles coupled bolts can provide favorable effects in hard rock mass,while the effects were negligible when installed in extremely soft coal mass.The wide set of multi-technique measurements helped to understand the mechanisms involved in the performance of the bolting system with coupling steel particles.

A combined survey to evaluate the thermal behavior of loess for a landslide-prone slope on the Heifangtai terrace in Northwest China

A combined survey including infrared thermography(IRT)and field-laboratory tests were conducted to analyze the thermal responses and thermal properties of loess on a landslide-prone loess slope in the Heifangtai terrace in Northwest China aiming at preliminarily demonstrating the potential of IRT as a complementary technique to the investigation of irrigation-induced loess landslides.Multitemporal thermographic surveys corresponding to various solar radiation intensities during the afternoon were carried out on the landslide-prone loess slope.Accordingly,the spatiotemporal distribution of the thermal responses within the observed slope surface was analyzed qualitatively and quantitatively.Meanwhile,field and laboratory investigations were also performed on the thermal properties of different landslide materials.The results indicate that loess,a landslide-prone deposit that usually has a relatively high water content,exhibits different thermal properties and anomalies,including a lower surface temperature and greater thermal inertia,compared to surrounding zones without landslides.The groundwater table and corresponding seepage line could also be obtained by determining the potential boundary between the thermal response distribution of landslide scarps and that of saturated deposits in the presence of landslides.The results of these investigations are expected to provide insight for future endeavors combining infrared thermography with other efficient survey methodologies(e.g.,InSAR,which can monitor the active displacement of a loess slope)to evaluate the activity of this kind of excessive irrigation-induced loess landslide.

Effects of Chinese tuina on the level changes of lumbar muscle temperature and serum 5-HT and β-EP in patients with low back pain

Objective:To analyze the level changes of the degree of back pain by visual analogue scale(VAS),lumbar function(Japanese Orthopaedic Association Scores,JOA),muscle temperature,serum serotonin 5-hydroxytryptamine(5-HT)andβ-endorphin(β-EP)in patients of low back pain(LBP).Methods:64 LBP patients treated in the tuina department of first affiliated hospital of Hainan Medical University were randomly divided into observation group(32 cases)and control group(32 cases).The control group was treated with traditional filiform acupuncture needling,the observation group was treated with Chinese tuina.VAS,JOA,muscle temperature,5-HT,β-EP,these indexes were tested before and after treatment.Results:The VAS and JOA score in the observation group were significantly lower than those in the control group(P<0.01),the muscle temperature in the observation group and the control group increased significantly(P<0.01),and the observation group was higher than that in the control group(P<0.05);5-HT、β-EP was significant difference before and after treatment(P<0.01),and the level in observation group was significantly higher than that in the control group,the difference was statistically significant(P<0.05).Conclusion:Chinese tuina has significant clinical efficacy in the treatment of LBP.The medical infrared thermal imaging technology and serum pain detection technology is conducive to objectively helpful to analyze the exact efficacy of tuina in the treatment of LBP and its impact on relevant indexes.

Non-invasive water status detection in grapevine(Vitis vinifera L.)by thermography

Grapevines are preferentially grown under mild to moderate water stress conditions to achieve the best compromise between wine quality and quantity.Water status detection for advanced irrigation scheduling is frequently done by predawn leaf water potential(ΨPD)or leaf stomata conductance(gL)measurements.However,these measurements are time and labor consuming.Therefore,the use of infrared thermography(IRT)opens up the possibility to study large population of leaves and to give an overview on the stomatal variation and their dynamics.In the present study IRT was used to identify water stress of potted grapevines.In order to define the sensitivity of IRT measurements to water stress,the IRT-based water status information were compared with simultaneously measuredΨPD and gL data.Correlations between IRT-based CWSI data on the one hand and gL andΨPD on the other showed the potential of IRT for water stress detection.However,the CWSI calculation procedure is laborious and the sensitivity of CWSI for water stress detection still needs to be improved.Therefore,further improvements are necessary in order to apply remote IRT-based systems for irrigation scheduling in the field.

Low-velocity impact response and infrared radiation characteristics of thermoplastic/thermoset composites

The low-velocity impact response and infrared radiation characteristics of composites have rarely been focused on simultaneously.This study aims to investigate the low-velocity impact response and infrared radiation characteristics of the glass fiber reinforced thermoplastic polypropylene and carbon fiber reinforced thermosetting epoxy resin laminates wildly used in the aircraft industry.The impact tests were conducted at five energy levels.Characterization parameters such as impact load,displacement,and absorbed energy were measured.The damage evolution and damage modes of the laminates were analyzed through active and passive thermography,ultrasonic C-scan,and optical microscope.The results indicate that Thermosets(TS)laminates exhibit better impact resistance,while Thermoplastics(TP)laminates show higher delamination ductility,and the maximum contact force of TP laminates is much smaller than that of the TS laminates under lowvelocity impacts,but the low bending stiffness and low ductility of the TP matrix cause the difference in energy absorption level between the two not significant.The temperature characteristic changes of passive infrared thermography heat maps could characterize the damage mode of the laminates.The correlation between the heat maps and the impact characteristic curves is explained;the fluctuation of the impact characteristic curves is directly related to the hot spot characteristics changes of the heat maps.More frequent curve fluctuations correspond to a larger and brighter hot spot on the heat map,which peaks at the maximum impact load after the impact force versus time curve fluctuation cutoff point,the maximum center displacement of the impact force versus displacement curve,and the maximum absorbed energy of the absorbed energy versus time curve.