FLIR vs SEEK thermal cameras in biomedicine: comparative diagnosis through infrared thermography

Application of smartphone-based infrared thermography devices for ocular surface thermal imaging

Infrared thermography (IRT) is a well-known imaging technique that provides a non-invasive displaying of the ocular surface temperature distribution. Currently, compact smartphone-based IRT devices, as well as special software for processing thermal images, have become available. The study aimed to determine the possible use of smartphone-based IRT devices for real-time ocular surface thermal imaging. This study involved 32 healthy individuals (64 eyes); 10 patients (10 eyes) with proliferative diabetic retinopathy (PDR) and absolute glaucoma; 10 patients (10 eyes) with PDR, who underwent vitreoretinal surgery. In all cases, simultaneous ocular surface IRT of both eyes was performed. In healthy individuals, the ocular surface temperature (OST) averaged 34.6 ± 0.8 °C and did not differ substantially between the paired eyes, in different age groups, and after pupil dilation. In our study, high intraocular pressure was accompanied by a decrease in OST in all cases. After vitreoretinal surgery in cases with confirmed subclinical inflammation, the OST was higher than the baseline and differed from that of the paired eye by more than 1.0 °C. These results highlight that smartphone-based IRT imaging could be useful for the non-invasive detection of OST asymmetry between paired eyes due to increased intraocular pressure or subclinical inflammation.

Utility of Thermal Imaging in Predicting Superficial Infections in Transfemoral Osseointegrated Implants

Background

Superficial infection is a common minor complication of transcutaneous implants that can be challenging to predict or diagnose. Although it remains unclear whether superficial infections progress to deep infections (which may require implant removal), predicting and treating any infection in these patients is important. Given that flap thinning during stage II surgery requires compromising vascularity for stability of the skin penetration aperture, we hypothesized that early skin temperature changes predict long-term superficial infection risk.

Methods

We obtained standardized thermal imaging and recorded surface temperatures of the aperture and overlying flaps 2 weeks postoperatively for the first 34 patients (46 limbs) treated with the Osseointegrated Prosthesis for the Rehabilitation of Amputees transfemoral implant system. We used two-sided t tests to compare temperatures surrounding the aperture and adjacent soft tissues in patients with and without subsequent infection.

Results

During median follow-up of 3 years, 14 limbs (30.4%) developed 23 superficial infections. At patients' initial 2-week visit, mean skin temperature surrounding the aperture was 36.3ºC in limbs that later developed superficial infections and 36.7ºC in uninfected limbs (P = 0.35). In four patients with bilateral implants who later developed superficial infection in one limb, average temperature was 1.5ºC colder in the infected limb (P = 0.12).

Conclusions

Superficial infections remain a frequent complication of transfemoral osseointegration surgery. We did not find differences in early heat signatures between limbs subsequently complicated and those not complicated by superficial infection. Further research should explore more objective measures to predict, diagnose, and prevent infections after osseointegration surgery.

A pilot study of skin stretching and blood circulation effects of dermal suctioning in dogs

Dermal suctioning has been reported to yield effects similar to those of cupping therapy in humans and horses, including pain reduction, increased blood circulation, improved flexibility, and healing. However, there is a dearth of reported outcomes concerning cupping or dermal suctioning in dogs. In this study, we examined the physiological effects of dermal suctioning in dogs. Employing the Medicell MINI pro8 device, dermal suctioning was applied to the dorsal surfaces of eight healthy beagle dogs for 20 min. Metrics such as body surface temperature, rectal temperature, pulse rate, respiratory rate, and skin pinch test results were gauged. Seven healthy beagle dogs were used as controls, and the same measurements were performed without dermal suctioning. The results showed a significant increase in the body surface temperature and skin pinch test results after dermal suctioning. We believe that the elimination of torsion in the blood vessels and nerves in the shallow fascia positively affected the thermoregulatory mechanism, resulting in an increase in body surface temperature, and also improving skin flexibility. Thus, dermal suctioning promotes subcutaneous blood circulation and improves skin flexibility in dogs. Further research is needed to identify the mechanisms underlying the effects of dermal suctioning and evaluate the stress in dogs caused by the implementation of the process.

Thermographic ranges of dromedary camels during physical exercise: applications for physical health/welfare monitoring and phenotypic selection

Despite the relatively wide knowledge of camel biomechanics, research into the immediate functional response that accompanies the execution of physical exercise remains unapproached. Therefore, selective breeding programs lack an empirical basis to achieve genetic improvement of physical stress tolerance traits and monitor camel welfare in this regard. Given the fact that physical exercise increases net heat production, infrared thermography (IRT) was selected to study the temperature changes at the skin surface of the different body areas in clinically normal dromedary camels, mostly relegated to leisure activities. Specifically, a lower dispersion at the individual level of the surface temperature at the scapular cartilage region, shoulder joint, and pelvis region, as well as lower values for Tmax and Tmin at the region of the ocular region, pectoral muscles, semimembranosus-semitendinosus muscles, and hind fetlock after exercise, have to be considered as breeding criteria for candidate selection. Such thermophysiological responses can be used as indirect measures of tissue activity in response to exercise and hence are reliable indicators of animal tolerance to physical exercise-induced stress. Additionally, sex, castration, age, and iris pigmentation significantly impacted the thermo-physiological response to exercise in the study sample, which can be attributed to hormones, general vigor, and visual acuity-mediated effects. These specific factors' influence has to be considered for the evaluation of physical performance and the design of selection schemes for physical-related traits in dromedaries.

A timeline of surgical lighting - Is automated lighting the future?

High quality surgical lighting is central to successful performance in the operating room and therefore to both patient care and treatment. This article discusses the origins of surgical lighting from the 1800s to today, with a focus on the four main forms. Their uses, advantages, and disadvantages are evaluated in an effort to identify the improvements required to improve today's current state of surgical lighting. Whilst these four mainstream types have served well for the past thirty years, the literature exposes opportunities for improvement and can be used to guide the pathway to transition from manual conventional methods to a more automated lighting (AL) approach. The concept of AL has been proposed using established and known technical approaches such as artificial intelligence (AI), 3D sensor tracking algorithms and thermal imaging. Whilst AL seems incredibly promising, further focused research must be undertaken to maximise its' effectiveness and allow for successful integration of this new technology into operating rooms today.

Lumbar Sympathetic Ganglion Block Facilitates Wound Healing in a Rat Ischemic Hindquarter Model

Lumbar sympathetic nerve block (LSNB) improves blood flow in the lower limbs and relieves pain involving the sympathetic afferents. This study examines the use of LSNB, but there are no reports of its use for the purpose of wound healing. Therefore, the authors planned the following study.

Methods

An ischemic limb ulcer was created on both lower limbs using a rat model (N = 18). The rats were divided into three groups, namely, A, B, and C. Group A received LSNB on one side (N = 6). Group B was sprayed with basic fibroblast growth factor preparation (trafermin/fiblast) on one side (N = 6). Group C was used as a control (N = 6). Lower limb temperature and the ulcer area were measured over time in each group. Furthermore, the correlation between the ulcer temperature and the ulcer area reduction rate was analyzed.

Results

Group A had higher skin temperature on the LSNB-treated side than on the nontreated side (P = 0.0022 < 0.05). Regarding the correlation between the average temperature and the ulcer area reduction rate, the correlation coefficient was as high as 0.691 in group A.

Conclusions

In the LSNB group, the skin temperature increased and the ulcer area decreased significantly. Conventionally, LSNB has been used for pain relief purposes, although the authors consider that it will be useful in the treatment of ischemic ulcers and that it is a potential treatment option for future chronic limb ischemia/chronic limb-threatening ischemia cases.

Theory and applications of InfraRed and thermal image analysis in ergonomics research

Designing products and services to fit human needs, wants and lifestyle require meaningful data. With Industry 4.0 and the internet of things, we have many ways to capture data using sensors and other means. InfraRed (IR) cameras are quite ubiquitous, especially for screening illness and wellness. They can provide a wealth of data on different objects and even people. However, their use has been limited due to processing complexities. With reducing cost and increasing accuracy of IR cameras, access to thermal data is becoming quite widespread, especially in medicine and people-related applications. These cameras have software to help process the data, with a focus on qualitative analyses and rather primitive quantitative analyses. In ergonomics, data from multiple users are essential to make reasonable predictions for a given population. In this study, using 4 simple experiments, several quantitative analysis techniques such as simple statistics, multivariate statistics, geometric modeling, and Fourier series modeling are applied to IR images and videos to extract essential user and population data. Results show that IR data can be useful to provide user and population data that are important for design. More research in modeling IR data and application software is needed for the increased application of IR information in ergonomics applications.

Automated and Controlled System for Analysis of Residual Limbs Thermograms of Transtibial Amputees

This work describes the development of a controlled cabin for capturing and analyzing thermal images. The motivation of such a device is to aid in the thermal image acquisition process within a confined space. The thermograms generated provide helpful information for analyzing the residual human limb in subjects with transtibial amputation. Such a study proposes a non-intrusive method to study the thermal activity on the amputee residual limb and seek a correlation to the quality of the socket. The proposed cabin ensures the repeatability of the thermograms acquisition process and provides an isolated workspace, thus improving the quality of the samples. The methodology consists of the design of the mechanical elements and parts of the system on computer-aided design software, the electronic instrumentation, a graphic user interface, and the control algorithm based on a barrier Lyapunov function to solve the trajectory tracking for the camera movements, and numerical simulations to illustrate the functionality and the manufacture of a prototype. The results obtained by implementing the control design on the automated cabin reveal that the thermal image acquisition process is completed following the desired trajectory with a mean squared tracking error of 0.0052. In addition, an example of the thermal images of two subjects and the results processing this class of pictures using the designed interface is shown.

Infrared Thermography Images Acquisition for a Technical Perspective in Screening and Diagnostic Processes: Protocol Standardized Acquisition

In this technical report we describe the thermographic setting protocol suitable for the FLIR T650SC thermal imager (FLIR Systems, Inc., Wilsonville, OR), an instrument that detects electromagnetic radiation in the infrared field which is physiologically emitted from the human body. FLIR T650SC thermal imager processes infrared radiations graphically and analyzes them through a specific software. In biomedicine, infrared thermography is a promising technique amongst other conventional methods used for detecting skin temperature differences considered as a possible sign of disturbances in the human body. Currently, automatic screening of temperature from a safe distance is an instrument utilized in the front line of the SARS CoV2 emergency.

The processing method of the thermogram considers an initial setting of constant parameters that cannot be subsequently modified such as temperature range, focusing and image composition. After the acquisition variable values important in the processing and analysis of the thermogram, such as detection of environment temperature, reflected temperature, emissivity, relative humidity and contrast palette, are set in the software. The analysis is performed using the FLIR Tools software.

In the biomedical field standardized acquisition of thermograms facilitates the identification of trigger points and areas of hyper- and hypothermia distributed on the skin surface and muscle bundles. The protocol made it possible to create images with the same acquisition method for all patients.

The thermal imaging camera is a valid screening tool because its execution is rapid, it is non-invasive, well-tolerated, and at a low cost for patients.

Implementation of Thermal Camera for Non-Contact Physiological Measurement: A Systematic Review

Non-contact physiological measurements based on image sensors have developed rapidly in recent years. Among them, thermal cameras have the advantage of measuring temperature in the environment without light and have potential to develop physiological measurement applications. Various studies have used thermal camera to measure the physiological signals such as respiratory rate, heart rate, and body temperature. In this paper, we provided a general overview of the existing studies by examining the physiological signals of measurement, the used platforms, the thermal camera models and specifications, the use of camera fusion, the image and signal processing step (including the algorithms and tools used), and the performance evaluation. The advantages and challenges of thermal camera-based physiological measurement were also discussed. Several suggestions and prospects such as healthcare applications, machine learning, multi-parameter, and image fusion, have been proposed to improve the physiological measurement of thermal camera in the future.

Thermal face recognition under different conditions

Background

A thermal face recognition under different conditions is proposed in this article. The novelty of the proposed method is applying temperature information in the recognition of thermal face. The physiological information is obtained from the face using a thermal camera, and a machine learning classifier is utilized for thermal face recognition. The steps of preprocessing, feature extraction and classification are incorporated in training phase. First of all, by using Bayesian framework, the human face can be extracted from thermal face image. Several thermal points are selected as a feature vector. These points are utilized to train Random Forest (RF). Random Forest is a supervised learning algorithm. It is an ensemble of decision trees. Namely, RF merges multiple decision trees together to obtain a more accurate classification. Feature vectors from the testing image are fed into the classifier for face recognition.

Results

Experiments were conducted under different conditions, including normal, adding noise, wearing glasses, face mask, and glasses with mask. To compare the performance with the convolutional neural network-based technique, experimental results of the proposed method demonstrate its robustness against different challenges.

Conclusions

Comparisons with other techniques demonstrate that the proposed method is robust under less feature points, which is around one twenty-eighth to one sixtieth of those by other classic methods.

Stress detection and monitoring based on low-cost mobile thermography

The high level of stress in modern life is one of the huge problems of the 21st century society, especially in the context of the Covid-19 pandemic. With the pandemic, the need for inexpensive, portable and easy-to-use health monitoring tools (mental and physical) has increased. Of particular importance here is mobile (smartphone) thermography, as it enables the initial detection and self-control of stress, which being intensified nowadays, is the cause of many diseases, depression and health problems. The smartphone thermal imaging camera responds to the strict sanitary guidelines, offering contact-free, painless and non-invasive operation. Additionally, it is included in the group of low-cost solutions available for home use. It is an alternative to commonly used (often expensive and unavailable to everyone): EMG, ECG, EEG, GSR or other high-cost stress detection tools. Thermal imaging by analyzing abnormalities or temperature changes allows for detection application. Therefore, the aim of this work is to determine the possibilities of a low-budget mobile thermal imaging camera in detecting stress, detecting and analyzing stress by identifying the characteristics of psychophysiological signals with the individual characteristics of the participants, along with the correlation. The participants’ reactions to the film introducing stress tension up to the climax of the action were recorded thermographically. Data was processed in OpenCV. In the usual observation, stress often remained unnoticed. However, the thermographic analysis provided detailed information on the impact of the film’s stressful situation on the participants, with the possibility of distinguishing the stages of stress. The results of the preliminary pilot study were presented, which indicated the variability of temperature and heart rate as important indicators of stress – with the simultaneous significance of individual characteristics of the participant. Smartphone stress thermography is a promising method of monitoring human stress, especially at home.

The Use of Infrared Thermal Imaging to Determine Functional Nasal Adequacy: A Pilot Study

Objective

The goal of this study was to establish a numeric threshold to separate functional from substantially obstructed noses using comparisons of thermal imaging and subjective scores.

Study Design

An inexpensive smartphone application and hardware attachment that uses infrared thermal imaging was tested to differentiate between substantial nasal blockage from an adequately functioning nose.

Setting

Sequential adult participants who presented to a public hospital otolaryngology clinic between June and August 2018 were asked to complete the Nasal Obstruction Symptom Evaluation (NOSE) tool.

Methods

A thermal video imaging device was used to record the difference in temperature (ΔT) between inspired (I) and expired (E) air at each nostril. The nostril ΔT between I and E air of patients with severe obstruction by the subjective measure (NOSE score) was compared with that of patients with minimal symptoms.

Results

A total of 26 participants were enrolled in the study. During normal respiration, Total ΔT for the nonobstructed group had a mean of 9.0, whereas the Total ΔT for the obstructed group had a mean of 7.69, a 17% difference that was statistically significant at P = .045. For the worst-performing nostril tested, ΔT for the nonobstructed group had a mean/median of 4°C, while the obstructed group had a mean of 3.23°C (median 3; 23.8% difference, P = .023).

Conclusion

Measures of thermal imaging, particularly at the threshold between the median scores of the worst-performing nostril, may be a useful clinical test to differentiate between a substantially obstructed nose from an adequately functioning nose, although more data are required.

Infrared thermography as a modality for tracking cutaneous temperature change and post-mortem interval in the critical care setting

PURPOSE

To evaluate the potential use of cutaneous facial temperature change as measured by an infrared camera as a marker of postmortem interval (PMI) in the minutes immediately following death.

METHODS

This was a prospective, observational pilot study using a convenience sample of all deaths which occurred in a room in an Intensive Care Unit equipped with a ceiling mounted thermal camera. Cutaneous temperature measurements were taken from 60 min antemortem to as long as possible postmortem.

RESULTS

A total of 134 separate measurements was taken from 5 patients, with 65 occurring antemortem, and 69 occurring post-mortem. The longest recorded post-mortem time was 130 min. A Kruskal-Wallis ANOVA testing the hypothesis that there was a difference in facial temperature at each of the different timepoints showed significance (p = 0.029). Post-Hoc comparisons were then performed to compare median temperature values at each timeframe to the baseline value. Compared to baseline, there was a significant difference in facial temperature at 30, 60, and 90 min (p = 0.007, p = 0.01, p = 0.016) (Table 2).

CONCLUSION

There is a statistically significant cutaneous facial temperature change in patients immediately following death as measured by a thermal camera. There is potential for infrared thermography to identify changes immediately before and after death in environments where traditional temperature measurement cannot be accomplished. More work needs to be done to confirm whether a precise postmortem interval (PMI) could be derived from these values.

Thermo-optic measurements and their inter-dependencies for delineating cancerous breast biopsy tissue from adjacent normal

The histopathological diagnosis of cancer is the current gold standard to differentiate normal from cancerous tissues. We propose a portable platform prototype to characterize the tissue's thermal and optical properties, and their inter-dependencies to potentially aid the pathologist in making an informed decision. The measurements were performed on 10 samples from five subjects, where the cancerous and adjacent normal were extracted from the same patient. It was observed that thermal conductivity (k) and reduced-scattering-coefficient (μ'_s ) for both the cancerous and normal tissues reduced with the rise in tissue temperature. Comparing cancerous and adjacent normal tissue, the difference in k and μ'_s (at 940 nm) were statistically significant (p = 7.94e-3), while combining k and μ'_s achieved the highest statistical significance (6.74e-4). These preliminary results promise and support testing on a large number of samples for rapidly differentiating cancerous from adjacent normal tissues.

Comparison of cutaneous facial temperature using infrared thermography to standard temperature measurement in the critical care setting

To assess the accuracy and precision of infrared cameras compared to traditional measures of temperature measurement in a temperature, humidity, and distance controlled intensive care unit (ICU) population. This was a prospective, observational methods comparison study in a single centre ICU in Metropolitan Melbourne, Australia. A convenience sample of 39 patients admitted to a single room equipped with two ceiling mounted thermal imaging cameras was assessed, comparing measured cutaneous facial temperature via thermal camera to clinical temperature standards. Uncorrected correlation of camera measurement to clinical standard in all cases was poor, with the maximum reported correlation 0.24 (Wide-angle Lens to Bladder temperature). Using the wide-angle lens, mean differences were − 11.1 °C (LoA  − 14.68 to  − 7.51),  − 11.1 °C ( − 14.3 to  − 7.9), and  − 11.2 °C ( − 15.23 to  − 7.19) for axillary, bladder, and oral comparisons respectively (Fig. 1a). With respect to the narrow-angle lens compared to the axillary, bladder and oral temperatures, mean differences were  − 7.6 °C ( − 11.2 to  − 4.0),  − 7.5 °C ( − 12.1 to  − 2.9), and  − 7.9 °C ( − 11.6 to  − 4.2) respectively. AUCs for the wide-angle lens and narrow-angle lens ranged from 0.53 to 0.70 and 0.59 to 0.79 respectively, with axillary temperature demonstrating the greatest values. Infrared thermography is a poor predictor of patient temperature as measured by existing clinical standards. It has a moderate ability to discriminate fever. It is unclear if this would be sensitive enough for infection screening purposes.Fig. 1

Smartphone-based imaging systems for medical applications: a critical review

SIGNIFICANCE

Smartphones come with an enormous array of functionality and are being more widely utilized with specialized attachments in a range of healthcare applications. A review of key developments and uses, with an assessment of strengths/limitations in various clinical workflows, was completed.

AIM

Our review studies how smartphone-based imaging (SBI) systems are designed and tested for specialized applications in medicine and healthcare. An evaluation of current research studies is used to provide guidelines for improving the impact of these research advances.

APPROACH

First, the established and emerging smartphone capabilities that can be leveraged for biomedical imaging are detailed. Then, methods and materials for fabrication of optical, mechanical, and electrical interface components are summarized. Recent systems were categorized into four groups based on their intended application and clinical workflow: ex vivo diagnostic, in vivo diagnostic, monitoring, and treatment guidance. Lastly, strengths and limitations of current SBI systems within these various applications are discussed.

RESULTS

The native smartphone capabilities for biomedical imaging applications include cameras, touchscreens, networking, computation, 3D sensing, audio, and motion, in addition to commercial wearable peripheral devices. Through user-centered design of custom hardware and software interfaces, these capabilities have the potential to enable portable, easy-to-use, point-of-care biomedical imaging systems. However, due to barriers in programming of custom software and on-board image analysis pipelines, many research prototypes fail to achieve a prospective clinical evaluation as intended. Effective clinical use cases appear to be those in which handheld, noninvasive image guidance is needed and accommodated by the clinical workflow. Handheld systems for in vivo, multispectral, and quantitative fluorescence imaging are a promising development for diagnostic and treatment guidance applications.

CONCLUSIONS

A holistic assessment of SBI systems must include interpretation of their value for intended clinical settings and how their implementations enable better workflow. A set of six guidelines are proposed to evaluate appropriateness of smartphone utilization in terms of clinical context, completeness, compactness, connectivity, cost, and claims. Ongoing work should prioritize realistic clinical assessments with quantitative and qualitative comparison to non-smartphone systems to clearly demonstrate the value of smartphone-based systems. Improved hardware design to accommodate the rapidly changing smartphone ecosystem, creation of open-source image acquisition and analysis pipelines, and adoption of robust calibration techniques to address phone-to-phone variability are three high priority areas to move SBI research forward.

Use of high-resolution thermography as a validation measure to confirm epidural anesthesia in mice: a cross-over study

BACKGROUND

Effective epidural anesthesia is confirmed in humans by sensory assessments but these tests are not feasible in mice. We hypothesized that, in mice, infrared thermography would demonstrate selective segmental warming of lower extremities following epidural anesthesia.

METHODS

We anesthetized 10 C57BL/6 mice with isoflurane and then inserted a PU-10 epidural catheter under direct surgical microscopy at T11-12. A thermal camera (thermal sensitivity ±0.05°C, pixel resolution 320x240 pixels, and spatial resolution 200 μm) recorded baseline temperature of front and rear paws, tail and ears. Thermography was assessed at baseline and 2, 5, 10, and 15 min after an epidural bolus dose of 50 μL bupivacaine 0.25% or 50 μL saline (control) using a cross-over design with dose order randomized and investigators blinded to study drug. Thermal images were recorded from video and analyzed using FLIR software. Effect over time and maximal effect (E_max) were assessed by repeated measures ANOVA and paired t-tests. Comparisons were between bupivacaine and control, and between lower vs upper extremities.

RESULTS

Epidural bupivacaine caused progressive warming of lower compared with upper extremities (P <0.001), typically returning to baseline by 15 min after administration. Mean (±SD) E_max was +3.73 (±1.56) °C for lower extremities compared with 0.56 (±0.68) °C (P=0.03) for upper extremities. Following epidural saline, there was no effect over time (E_max for lower extremities -0.88 (±0.28) °C compared with the upper extremities -0.88 (±0.19) °C (P >0.99).

CONCLUSIONS

Thermography is a useful tool to confirm epidural catheter placement in animals for which subjective, non-noxious, sensory measures are impossible.

Influence of infrared camera model and evaluator reproducibility in the assessment of skin temperature responses to physical exercise

Infrared thermography (IRT) has been gaining in popularity in clinical and scientific research due to the increasing availability of affordable infrared cameras. This study aims to determine the similarity of measurement performance between three models of IRT camera during assessment of skin temperature before and after physical exercise. Three models of FLIR thermographic cameras (E60bx, Flir-One Pro LT, and C2) were tested. Thermal images were taken of the foot sole, anterior leg, and anterior thigh from 12 well-trained men, before and after a 30-min run on a treadmill. Image files were blinded and processed by three evaluators to extract the mean, maximum, and standard deviation of skin temperature of the region of interest. Time for data processing and rate of perceived effort was also recorded. Data processing was slower on the E60bx (CI95% E60 vs C2 [0.2, 2.6 min], p = 0.02 and ES = 0.6); vs. Flir-One [0.0, 3.4 min], p = 0.03 and ES = 0.6) and was associated with lower effort perception (E60 3.0 ± 0.1 vs. Flir-One 5.6 ± 0.2 vs C2 7.0 ± 0.2 points; p < 0.001 and ES > 0.8). The C2 and Flir-One cameras underestimated the temperature compared with the E60. In general, measuring mean temperature provided higher camera and examiner intra-class correlations than maximum and standard deviation, especially before exercise. Moreover, post exercise mean skin temperatures provided the most consistent values across cameras and evaluators. We recommend the use of mean temperature and caution when using more than one camera model in a study.

Local and Contralateral Effects after the Application of Neuromuscular Electrostimulation in Lower Limbs

Neuromuscular electrostimulation (NMES) has been used mainly as a method to promote muscle strength, but its effects on improving blood flow are less well known. The aim of this study is to deepen the knowledge about the local and contralateral effects of the application of symmetric biphasic square currents on skin temperature (Tsk). An experimental pilot study was developed with a single study group consisting of 45 healthy subjects. Thermographic evaluations were recorded following the application of NMES to the anterior region of the thigh. The results showed an increase in the maximal Tsk of 0.67% in the anterior region of the thigh where the NMES was applied (p < 0.001) and an increase of 0.54% (p < 0.01) due to cross-education effects, which was higher when the NMES was applied on the dominant side (0.79%; p < 0.01). The duration of the effect was 20 min in the dominant leg and 10 min in the nondominant one. The application of a symmetrical biphasic current (8 Hz and 400 μs) creates an increase in the maximal Tsk at the local level. A temperature cross-education effect is produced, which is greater when the NMES is applied on the dominant side. This could be a useful noninvasive measurement tool in NMES treatments.

Detecting Vasodilation as Potential Diagnostic Biomarker in Breast Cancer Using Deep Learning-Driven Thermomics

Breast cancer is the most common cancer in women. Early diagnosis improves outcome and survival, which is the cornerstone of breast cancer treatment. Thermography has been utilized as a complementary diagnostic technique in breast cancer detection. Artificial intelligence (AI) has the capacity to capture and analyze the entire concealed information in thermography. In this study, we propose a method to potentially detect the immunohistochemical response to breast cancer by finding thermal heterogeneous patterns in the targeted area. In this study for breast cancer screening 208 subjects participated and normal and abnormal (diagnosed by mammography or clinical diagnosis) conditions were analyzed. High-dimensional deep thermomic features were extracted from the ResNet-50 pre-trained model from low-rank thermal matrix approximation using sparse principal component analysis. Then, a sparse deep autoencoder designed and trained for such data decreases the dimensionality to 16 latent space thermomic features. A random forest model was used to classify the participants. The proposed method preserves thermal heterogeneity, which leads to successful classification between normal and abnormal subjects with an accuracy of 78.16% (73.3-81.07%). By non-invasively capturing a thermal map of the entire tumor, the proposed method can assist in screening and diagnosing this malignancy. These thermal signatures may preoperatively stratify the patients for personalized treatment planning and potentially monitor the patients during treatment.

Automated thermal imaging for the detection of fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) comprises a spectrum of progressive liver pathologies, ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. A liver biopsy is currently required to stratify high-risk patients, and predicting the degree of liver inflammation and fibrosis using non-invasive tests remains challenging. Here, we sought to develop a novel, cost-effective screening tool for NAFLD based on thermal imaging. We used a commercially available and non-invasive thermal camera and developed a new image processing algorithm to automatically predict disease status in a small animal model of fatty liver disease. To induce liver steatosis and inflammation, we fed C57/black female mice (8 weeks old) a methionine-choline deficient diet (MCD diet) for 6 weeks. We evaluated structural and functional liver changes by serial ultrasound studies, histopathological analysis, blood tests for liver enzymes and lipids, and measured liver inflammatory cell infiltration by flow cytometry. We developed an image processing algorithm that measures relative spatial thermal variation across the skin covering the liver. Thermal parameters including temperature variance, homogeneity levels and other textural features were fed as input to a t-SNE dimensionality reduction algorithm followed by k-means clustering. During weeks 3,4, and 5 of the experiment, our algorithm demonstrated a 100% detection rate and classified all mice correctly according to their disease status. Direct thermal imaging of the liver confirmed the presence of changes in surface thermography in diseased livers. We conclude that non-invasive thermal imaging combined with advanced image processing and machine learning-based analysis successfully correlates surface thermography with liver steatosis and inflammation in mice. Future development of this screening tool may improve our ability to study, diagnose and treat liver disease.

A Cost-Effective System for Aerial 3D Thermography of Buildings

Three-dimensional (3D) imaging and infrared (IR) thermography are powerful tools in many areas in engineering and sciences. Their joint use is of great interest in the buildings sector, allowing inspection and non-destructive testing of elements as well as an evaluation of the energy efficiency. When dealing with large and complex structures, as buildings (particularly historical) generally are, 3D thermography inspection is enhanced by Unmanned Aerial Vehicles (UAV—also known as drones). The aim of this paper is to propose a simple and cost-effective system for aerial 3D thermography of buildings. Special attention is thus payed to instrument and reconstruction software choice. After a very brief introduction to IR thermography for buildings and 3D thermography, the system is described. Some experimental results are given to validate the proposal.

Main findings and advances in bioinformatics and biomedical engineering- IWBBIO 2018

In the current supplement, we are proud to present seventeen relevant contributions from the 6th International Work-Conference on Bioinformatics and Biomedical Engineering (IWBBIO 2018), which was held during April 25-27, 2018 in Granada (Spain). These contributions have been chosen because of their quality and the importance of their findings.