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This article elucidates the need to consider the inherent spatial transfer function (blur), of any thermographic instrument used to measure thermal fields. Infrared thermographic data were acquired from a modified, commercial, laser-based powder bed fusion printer. A validated methodology was used to correct for spatial transfer function errors in the measured thermal fields. The methodology was found to make a difference of 40% to the measured signal levels and a 174 °C difference to the calculated effective temperature. The spatial gradients in the processed thermal fields were found to increase significantly. These corrections make a significant difference to the accuracy of validation data for process and microstructure modeling. We demonstrate the need for consideration of image blur when quantifying the thermal fields in laser-based powder bed fusion in this work.

Jitka Fricova,1,2 Marketa Janatova,3 Martin Anders,4 Jakub Albrecht,4 Richard Rokyta2 1Charles University, 1st Faculty of Medicine, General University Hospital, Department of Anesthesiology, Resuscitation and Intensive Medicine, Pain Management Center, Prague, Czech Republic; 2Charles University, 3rd Faculty of Medicine, Department of Normal, Pathological and Clinical Physiology, Prague, Czech Republic; 3Charles University, 1st Faculty of Medicine, General University Hospital, Department of Rehabilitation Medicine, Prague, Czech Republic; 4Charles University, 1st Faculty of Medicine, General University Hospital, Department of Psychiatry, Prague, Czech Republic Background: Infrared thermography can be used to obtain more complete information about a patient’s condition. The method can be used in various medical applications for monitoring acute and chronic orofacial pain syndrome. With this diagnostic method, thermal differences in the examined region are usually compared to the same reference region on the opposite side of the body. Methods: Infrared quantitative thermography is a non-invasive method for contactless monitoring of dynamic thermal fields on a surface, or in this case, the human body. This method is based on detection of infrared radiation, which is naturally emitted from the surface of the body. In a pilot project with a patient having orofacial pain, changes before and after repetitive transcranial magnetic brain stimulation treatment were assessed. Results: First-day measurements found significantly higher maximum, minimum, and average temperatures, before and after therapy, in the area where the patient subjectively reported pain. The fifth and final measurements, before and after therapy, found only a slight elevation of the maximum temperature of the assessed regions, relative to the same regions on the opposite side of the face. Conclusion: During the measurements on the fifth day, a thermal difference greater than 0.4°C was only observed relative to the minimum temperatures associated with the regions of self-reported pain before and after therapy. For validation of the effects, this method will need to be tested using a randomized, double-blind study with a larger number of patients. Keywords: orofacial pain, thermovision, infrared thermography, transcranial stimulation

The objective of this paper is to use quantitative thermography for fatigue damage assessment and life prediction of welded components. The energy dissipation during fatigue process is taken as an effective index of fatigue damage to develop a nonlinear damage accumulation model, and the model is extended to evaluate the fatigue damage and residual life of the specimen subjected to variable loading. Experiments are performed to validate its applicability, and the relationships between the fatigue damage variable to the cycle number and the accumulated energy dissipation are presented and discussed. The results show that the energy dissipation has the same trend as the temperature increment evolution, and a power law relationship between the stress range and the energy dissipation is experimentally determined. The linear relationship between the accumulated energy dissipation and the cycle number is confirmed at different constant stress levels, and the total energy dissipation to failure is shown to be a constant value. The developed nonlinear damage accumulation model is used to predict the residual fatigue life, and a good agreement is achieved. It is concluded that the developed approach is applicable for fatigue damage accumulation and residual life evaluation of materials.

There are several parameters that can influence significantly the measurement of surface temperatures using IRT. For that reason, this issue is deeply discussed in this chapter, including a comparison between the values obtained using three different devices (infrared camera, infrared thermometer and type T thermocouples). The chapter describes the methodology and the results attained in two experimental campaigns, one in situ and the other one in laboratory. In the in situ case study, the surface temperature of various finishing materials on the facades of a building was measured in different periods of the day and at different distances. The second campaign (laboratory) consisted in selecting materials with different emissivity and exposing them to external environmental conditions, while measuring their surface temperature.

Thermal imaging cameras are expensive, particularly those designed for measuring high temperature objects with low measurement uncertainty. A wide range of research and industrial applications would benefit from lower cost temperature imaging sensors with improved metrology. To address this problem, we present the first ever quantification methodology for the temperature measurement performance of an ultra-low cost thermal imaging system based on a smartphone sensor. The camera was formed from a back illuminated silicon Complementary Metal Oxide Semiconductor (CMOS) sensor, developed for the smartphone camera market. It was packaged for use with a Raspberry Pi computer. We designed and fitted a custom-made triplet lens assembly. The system performance was characterised with a range of state-of-the-art techniques and metrics: establishing a temperature resolution of below 10 &deg, C in the range 600&ndash, 1000 &deg, C. Furthermore, the scene dependent aspects of combined uncertainty were considered. The minimum angular subtense for which an accurate thermal measurement could be made was determined to be 1.35&deg, which corresponds to a 23 mm bar at a distance of 1 m, or 45:1 field-of-view in radiation thermometer nomenclature.

Improving the thermal performance of the existing building stock is essential to significantly reduce the overall energy consumption in the building sector. A key objective is the retrofitting of the existing building envelope. A necessary first step in the building envelope optimization process is the assessment of its actual thermal performance. This assessment should be repeated after retrofitting to clearly define the improvements that were made and the heat loss reduction that was achieved. In this study, an efficient, non-destructive, in-situ measurement method, based on an outdoor infrared thermographic survey, is developed to determine the thermal bridging performance. As wind velocity significantly influences the heat losses through the building envelope, this study includes quantification of the wind velocity impact on the Psi-value. This was assessed by undertaking ITT of the same thermal bridge at various wind velocities, in a controlled environment, in a hot box device. The results showed that the Psi-value is highly dependent on wind velocity so that measurement of the Psi-value taken at different wind conditions cannot be directly compared. An adjustment procedure is proposed that can be used to convert the Psi-value measured at any wind velocity to a standard value corresponding to a velocity of 4 m/s. From a practical point of view, this adjustment procedure makes the methodology widely applicable. Enterprise Ireland for the provision of financial support for this study through Innovation VoucherIV-2014-4203. peer-reviewed 2019-09-18

Objectives To correlate Frey's syndrome with subjective symptoms, Minor's starch iodine test results, and infrared thermography measurements, and to discuss the utility of thermography as a quantitative diagnostic method. Methods This study included 59 patients who underwent unilateral parotidectomy. A subjective clinical questionnaire and an objective Minor's starch iodine test were performed to evaluate the incidence of Frey's syndrome. Infrared thermography was performed, and the subjects were divided into seven groups according to the temperature differences between operated and unoperated sites. The thermal differences were correlated with the results from Minor's starch iodine test and the subjective symptoms questionnaire. Results Of the 59 patients, 20 patients (33.9%) reported subjective symptoms after eating; 30 patients (50.8%) tested positive for Minor's starch iodine test, 19 patients (63.3%) of which reported subjective symptoms. Of the 29 patients who were negative for the iodine test, 2 patients (6.9%) reported subjective symptoms. Thus, subjective symptoms were well correlated with Minor's starch iodine test (r=0.589, P

A key aspect in assessing the thermal standard of building envelopes is the quantification of the heat loss though thermal bridging, which can be expressed in terms of the linear thermal transmittance Psi. Values of W may be obtained from tabulated values for standard building details, from numerical modelling or from measurement. Where the internal structure of the building envelope is unknown, which is very often the case, measurement is the only option. This study shows how the infrared thermography technique (ITT) can be used as a non-invasive and easy-to-use method to provide quantitative measures of the actual thermal bridging performance. The novelty of this approach includes evaluation of the actual heat flow rate caused by thermal bridge q(TB) and Psi-value by means of the ITT solely, without any supporting methods. Another important aspect of the methodology is that it accounts for the correlation between the surface temperature and the convective and radiative heat transfer coefficients. Values for these coefficients are assessed for the whole range of the surface temperatures recorded on the thermogram resulting in improve accuracy. The q(TB) and Psi-value calculated using the presented methodology fully mirrors the real thermal performance of the thermal bridge. The methodology has been tested under laboratory conditions in a steady state in a hot box with excellent agreement. (C) 2016 Elsevier B.V. All rights reserved. peer-reviewed

Global climate change is one of the most important challenges and threats to economic, social and environmental sustainability.. Reducing electrical power demand is an important and necessary step in lessening global climate change and preserving our energy resources for future generations. The objective of this work is the development and demonstration of a quantitative thermographic system to rapidly and noninvasively determine in-use electrical motor efficiency. The development has included testing of four motors in a controlled laboratory setting. This setting permits the complete and steady measurement of electrical power draw, mechanical load applied in addition to the thermal imaging. It provides a reliable means to validate the quantitative thermographic system. The thermographic technique proved to be reliable for all motors at 60% or more of full load.

This is a research effort that helps to define thermal infrared imaging as a diagnostic tool in breast cancer detection, which can be used as a complementary modality to traditional mammography. Our approach consists in the non-topological and the hybrid methods of computerized thermogram classification. The principle task is to find the most significant thermopathological features. 1 Introduction The breast cancer is the second most often cancerous cause of death among women and the second most frequent type of cancer at all. Nevertheless it is proved that early stages of breast cancer are well treatable. That is why the early detection is so important. Thermography is non-invasive and has proved ability to detect physiological changes caused by early cancer growth. Our approach to thermography application consists in quantitative computer performed analysis and classification of digital thermograms of breasts. This paper summarizes our existing research results. 2 Methods

Summary form only given. The needs of the space program for quantitative thermography is reviewed and the implications of NASA's advanced development work in thermography and its relationship to human perception and clinical diagnostics are discussed, with emphasis on image information processing capabilities of representative observer vision systems. Areas in which further work is needed are identified. >

Significant new technological advances in biomedical engineering in detector material, staring focal plane array (SFA) sensors, integrated circuits, and high performance photon detectors such as mercury-cadmium-telluride (MCT) operating in the 70 K to 120 K temperature range enable the clinician in medicine to "see more". With third generation technology coupled with concomitant advances in biological medicine in gene, receptor specific, and enzymatic molecular medicines, interventional quantitative thermography enables a better understanding of interactive thermal pattern recognition in neuropathic, myopathic, angiopathic and scleropathic syndromes as aides in diagnosis and monitoring treatment in pain management. As a result of these advances, we can now demonstrate two types of interventional computerized thermal imaging: (1) chemically mediated-receptor specific; and (2) peripheral neuropathic localization of the somato-autonomic thermatome. This study focuses on new medical applications of these techniques, and reviews the clinical physiology mediated by interventionally monitored digitalized infrared thermal imaging (DITI).

Paget's disease of bone, identified over 200 years ago, is characterised by altered bone metabolism, increased heat and bending of long weight bearing bones such as the tibiae. Infrared thermography is an efficient means of monitoring the temperature changes over actively diseased bone. Fundamental studies to determine the cause of temperature changes have been made, using a mathematical model of heat flow in the tibia. These indicate that high osseous vascularity is the major cause of the temperature increase. Changes in temperature often precede clinical response to treatment or remission. A series of case studies using Calcitonin, and also Etidronate therapy for periods up to 4 years, have been recorded using a thermal index. Quantitative thermography is the ideal means for monitoring the progress of the disease and its treatment.

A 49-year-old patient with pulmonary hypertrophic osteoarthropathy was treated with 0.4 mg of atropine sulfate every 4 hours for 14 days. A good clinical response was obtained as measured by handgrip strength, range of motion, and quantitative thermography. Chemical vagotomy supports the hypothesis of the vagal reflex as the pathophysiological mechanism in pulmonary hypertrophic osteoarthropathy.

1 Three intra-articular prednisolone analogues have been studied in a group of forty-six rheumatoid arthritic subjects. Each compound was tested at 50 mg and 100 mg dose over 3 weeks. 2 The anti-inflammatory effect was assessed by quantitative thermography. Systemic escape of the drug was monitored by plasma prednisolone and cortisol levels. 3 Both the systemic escape from the joint and the duration of effect on injected and uninjected knees were related to drug solubility. 4 Depression of plasma cortisol occurred with all three preparations and was most prolonged with the long-acting preparation. 5 Increasing the dose from 50 mg to 100 mg increased the antiflammatory effect only with the soluble acetate preparation.

Summary A case of hypertrophic pulmonary osteoarthropathy (HPOA) is described, together with synovial fluid cytology and synovial histology. A new approach to therapy is described using adrenergic blockade. The effectiveness of this regime was assessed by quantitative thermography. The successful results support the neurogenic hypothesis for the aetiology of HPOA.

The basal temperature of the hands has been measured by quantitative thermography in a group of normal controls and rheumatoid patients exhibiting Raynaud's phenomenon. The thermographic index for both the dorsum of the hand and the fingers was significantly lower in the patients with Raynaud's. Oral treatment with inositol nicotinate (Hexopal) was followed by an initial rise in the thermographic index in both areas. After the initial increase the temperature fell again but then rose after two months treatment. At nine months two subjects on continuous therapy had higher indices than the four who had discontinued therapy. It is suggested that long-term treatment with nicotinate acid derivatives may produce improvement in the peripheral circulation by a different mechanism than the transient effect detected by short-term studies.

The human body is an efficient radiator. Infra red energy can be detected and displayed to provide a thermal map of the skin surface. Many biological factors control skin temperature, and strict control of technique is essential, to establish meaningful measurements. A variety of options in instrumentation are currently available including computerised data processing. Temperature abnormalities may be used to aid diagnosis, and monitor treatment. Thermography can be used to indicate changes in thermal pattern, temperature range, and response to a stimulation test. In articular joint diseases, metabolic disorders, and circulatory diseases the value of quantitative thermography has been demonstrated.