Facial Temperature Research Articles

Thermal Facial Profile and Orofacial Myofunctional Aspects in Movement Disorder Patients: Comparison Between Parkinson Disease and Spinocerebellar Ataxia Type 3.

To evaluate the orofacial myofunctional characteristics, masticatory performance and facial thermal profile in individuals with Parkinson disease (PD) and spinocerebellar ataxia (SCA3), comparing with healthy control ones. Seventy-two participants aged between 30 and 85 years were evaluated and divided into PD, SCA3 and control groups. The assessments included clinical evaluation using the Orofacial Myofunctional Evaluation with Scores protocol (orofacial structures, mastication, swallowing and breathing aspects), masticatory performance assessed with a colour-changeable chewing gum and infrared thermography. The Kruskal-Wallis, one-way ANOVA and Wilcoxon tests were applied. With the exception of face and tongue, a difference was seen in the cheek, maxillomandibular relationship, lips, mentalis muscle and palate appearance and posture between patients and healthy control participants. Orofacial mobility, swallowing and masticatory function also scored higher in the control group. The SCA3 and PD groups required more time to eat the test-food and showed greater facial temperature asymmetries than the control one (p < 0.05). Masticatory performance measured by chewing gum did not differ. Facial temperature asymmetries, swallowing and masticatory function scores and the time needed by the SCA3 and PD groups to eat the test-food were different from healthy participants, drawing attention to the impaired orofacial functions in patients with neurodegenerative disorders.

Embryonic thermal manipulation and post-hatch dietary guanidinoacetic acid supplementation alleviated chronic heat stress impact on broiler chickens

The study investigated the effects of embryonic thermal manipulation (TM) and post-hatch guanidinoacetic acid (GAA) supplementation on male broiler chickens exposed to chronic heat stress (HS). Ross 308 eggs (n = 710) were randomly assigned to control (37.8 °C, 56% RH) or TM (39.5 °C, 65% RH for 12 h/day from embryonic day 7–16) treatments. After hatching, chicks were further assigned to four dietary treatments (n = 12 birds/pen, 5 replicates/treatment): control, control with 1.2 g/kg GAA supplementation (CS), TM, and TM with 1.2 g/kg GAA supplementation (TMS). All birds were subjected to chronic HS (32–36 °C and 55% RH for 6 h/day) from day 28–42. Embryonic TM treatment decreased hatchability, hatching weight (HW), and facial temperature (FT). During the pre-HS period (days 1–28), no significant differences in feed conversion ratio (FCR) and mortality were observed, although the TM group exhibited the lowest body weight gain (BWG). Following HS exposure (days 29–42), the TMS group displayed significantly higher BWG than the control and CS groups. The TM and TMS groups also demonstrated significantly lower FCR and mortality rates during this period. Across the entire period (days 1–42), BWG was significantly higher in the TMS group compared to other groups. Furthermore, TM and TMS treatments were associated with lower mortality rates, improved FCR, better European Performance Efficiency Index (EPEI), and reduced abdominal fat deposition. The experimental treatments did not significantly affect intestinal morphology or most blood parameters, except triiodothyronine (T3), thyroxine (T4), and uric acid. Plasma concentrations of T3, T4, and uric acid were significantly lower in the TM and TMS groups compared to the control and CS treatments. The findings suggest that a combined strategy of embryonic TM and post-hatch dietary GAA supplementation may not only alleviate the detrimental effects of HS but also promote beneficial physiological responses in broiler chickens.

Utility of facial thermography in the recognition of acute pain in hospitalized cats (Felis catus)

Different clinical conditions have been associated with the presence of pain in animals, so understanding the pathophysiological changes associated with their response is essential in in-hospital clinical monitoring. The objective of this study was to describe the usefulness of facial thermography in the recognition of acute pain in hospitalized cats (Felis catus), for which 71 cats were studied with an average weight of 4.3±1.4 Kg and an age average of 4.4±3.5 years. Facial temperature values were obtained in different region of interest (ROI) and compared according to the values of the Grimace pain scale in cats according to the following subclassification: Group 1, control animals (n=10); Group 2, animals classified with score 0-3 (n=21); Group 3, animals classified with score 4-6 (n=30) and Group 4, animals classified with score 7-10 (n=10). The global average temperature of the facial (F), auricular (A), periocular (PO), nasal (N) and rectal (R) regions was 33.7±1.9; 31.4±3.6; 32.1±0.9; 28.9±4.5 and 38.3±0.8 oC respectively. A difference (p&lt;0.05) was observed between the temperature of A and PO as well as between PO and N, but not between A and N. The present study allowed us to show an increase (p=0.0484) in the temperature mean PO ROI in G4 animals compared to G1 and a correlation with R temperature and peak temperature in the PO region in all groups. It is concluded that the increase in temperature of the periocular region and the nasal plane observed through infrared thermal imaging of the facial surface of hospitalized cats suggests the presence of clinically relevant acute pain. Facial thermography is a safe and non-invasive diagnostic method that complements other methods of identifying pain in cats.

Facemask vapor trapping, condensation, and thermoregulation

The widespread adoption of facemasks in various contexts has highlighted challenges associated with prolonged mask-wearing. Despite their effectiveness in preventing the spread of pathogens, issues such as discomfort, stuffiness, and fogging of eyeglasses can deter individuals from wearing masks consistently. Understanding the mechanisms of thermal and humidity regulation during facemask use is crucial for addressing these challenges. This study investigates the impact of face mask-wearing on facial thermoregulation and moisture accumulation, comparing conditions with and without masks. An integrated computational model was developed to consider respiratory flows, tissue heat generation, skin convective heat dissipation, the influence of inhaled cool air and exhaled warm air, and their interactions with the mask media. Model validation was conducted using complementary Schlieren imaging and transient temperature measurements. Results reveal significant increases in facial temperature with well-fitted masks and highlight the role of trapped moisture inside the mask. Thermo-humidity variations beneath the mask and condensations in the mask were quantified, providing insights into facemask-wearing thermoregulation. The effects of moist vs. dry air, steady vs. tidal breathing, and with vs. without buoyancy were quantitatively compared. These findings have implications for improving mask design and promoting adherence in diverse environmental settings. Addressing these discomfort-related challenges is crucial for enhancing mask adherence and ensuring adequate protection.

What not to do in facial infrared thermographic measurements: A post data enhancement

The accuracy of infrared thermographic measurements depends on several factors, including movement of target. In this study, accuracy of nose tip temperatures obtained in a mental workload assessment using a thermal imaging camera were impacted by participants’ movement and camera zooming/panning. To correct these measurement errors, we compared manual facial landmark identification techniques using data labelling software with an automated deep learning-based approach utilised for facial landmark tracking and evaluated both against the built-in tracking features of the thermal camera, Thermal Spot Tracking. Using the Manual Thermal Landmark Annotation measurements as the ground truth, our results show that the Automated Facial Feature Tracking approach, which is the AI based approach performed better than the Thermal Spot Tracking as it matched comparatively more spatial coordinates and temperature datapoints as well as showed comparatively lower mean relative error. The study highlights the potential of AI in enhancing the accuracy of thermographic measurements, particularly in applications involving facial temperature analysis.

Thermal comfort prediction in multi-occupant spaces based on facial temperature and human attributes identification

Research on thermal comfort prediction has garnered significant attention, with numerous studies focusing on predicting individual thermal comfort through various physiological indicators. However, these methods often lack reliability in long-distance, multi-occupant spaces and fail to utilize RGB image information fully. To address these limitations, this study introduces a new method for predicting thermal comfort in multi-occupant spaces by integrating individual attributes and facial temperature features. The research extracts human body attributes from RGB images and temperature features from different facial regions using image registration and deep learning algorithms. Results show that specific facial regions (cheeks, nose, eyes) combined with human attributes effectively predict thermal comfort. In contrast, the forehead, mouth, and chin are less reliable due to their sensitivity to external influences. Among various models, the LightGBM model achieves the highest accuracy at 90.04 ± 4.46%, demonstrating the effectiveness of the model this study proposed. This study offers a novel perspective for thermal comfort prediction in various settings, such as classrooms and lecture halls.

Exploring the Human Response to Anger: Uncovering Insights through Infrared Thermography and Experimental psychology

This study examines how exposure to angry versus neutral facial expressions affects facial temperature, aiming to validate thermograms as reliable measures of emotional responses. We focus on Saudi youth and explore the impact of different stimuli categories (young vs. old, male vs. female) on subjective feelings recorded by thermal cameras.The research involved a sample of 40 male participants selected from King Fahd University of Petroleum and Minerals (KFUPM) in Saudi Arabia, with an average age of 21.8 years (SD = 1.3). All participants had normal or corrected-to-normal visual acuity. The study comprised two experiments to examine the impact of exposure to angry versus neutral faces on physiological responses. Thermal data were collected using infrared thermography, focusing on variations in facial temperature as a key indicator of physiological reactions. Participants were exposed to stimuli consisting of angry and neutral faces from various demographic categories, including males, females, young individuals, and elderly adults. This comprehensive methodology combined behavioral analysis and infrared thermography techniqueThe behavioral findings indicated that individuals exhibited increased response times (RTs) when classifying angry stimuli compared to neutral face stimuli. Infrared thermography revealed a notable impact of anger, particularly in Region of Interest 5 (the area around the upper jaw). This effect was especially pronounced in individuals exposed to angry facial expressions, but not in those analyzing angry expressions of younger individuals.These findings provide insight into the unique physiological responses triggered by angry facial expressions, specifically identifying temperature rises in specific facial areas. The results contribute to our understanding of the physiological mechanisms involved in the processing of facial expression recognition.

Thermoregulatory Responses To Lying Based on Age and Temperature

The main goal that was trying to be achieved throughout the course of this project was to determine if a subject is lying, based on the body temperature of an individual. This can also be known as the thermoregulatory responses in the metopic suture and the apex region between male and females. When law enforcement tries to determine whether a subject is lying, they could be able to figure it out based on the subject’s facial temperature increasing or decreasing. The two points, forehead and nose, were chosen because there is a location in the brain called the insula, which is located deep within the lateral sulcus of the brain, which shows a difference in temperature when a lie is told. Insula activates brown adipose tissue to release heat, causing this phenomenon to occur. Ten subjects were used. Thirty questions were posed to each subject, and they were permitted to tell either the truth or a lie. After every question, the forehead and nose temperatures were taken. The results showed that when male and females lie, their temperature increases. The explanation for this is the area in the brain called the insula, which is more active in females and people over the ages of eighteen. For high insular activity to happen, it means the brain is trying hard to perform a complex task.

The potential of in ovo-fed amino acids to alleviate the effects of heat stress on broiler chickens: effect on performance, body temperature, and oxidative status during the finisher phase

The aim of the current study was to investigate the potential of in ovo-fed amino acids (AA) to reduce the effects of heat stress on finishing broiler chickens. To achieve this, a total of 1,400 fertile hatching eggs were randomly distributed into 5 groups (n = 280/group) and injected with one of the following in ovo treatments on embryonic day 18: 52 µL of sterile diluent/egg (CTRL), CTRL + 1.0 mg of L-Leucine (T1), CTRL + 0.45 mg of leucine + 1.15 mg of methionine (T2), CTRL + 3.0 mg of methionine + 2.0 mg of cysteine (T3), and CTRL + 0.40 mg of leucine + 1.60 mg of methionine + 1.60 mg of cysteine (T4). After hatch, chicks were allocated according to a complete randomized block design comprising 2 thermal conditions: thermoneutral (24°C, 45% RH) and heat stress (34°C, 55-60% RH) with 5 pens/group/condition. The cyclical heat stress regimen (10 h/d) was then applied from d 29 to d 34. Compared to the CTRL group, T3 and T4 exhibited a higher BW during the starter phase (P < 0.001). T4 also had a lower feed conversion ratio (FCR) than CTRL during this same phase (P = 0.03). During the grower phase, males of all treatment groups consistently exhibited higher BW compared to the CTRL group, which was not observed among female birds (PSex × TRT = 0.005). During the finisher phase, the in ovo treatment effect on performance was not significant. However, heat-stressed birds from treatment group T3 and T4 exhibited lower facial temperatures (Pday × TRT < 0.001) as well as lower plasma (Pcondition x TRT = 0.039) and liver (Pcondition x TRT < 0.001) malonaldehyde concentrations compared to the CTRL group. In conclusion, in ovo-fed AA have the potential to modulate the effects of heat stress on finishing broiler chickens by limiting its detrimental consequences, including increased body temperature and oxidative damage.

Infrared Thermography in Assessment of Facial Temperature of Racing Sighthound-Type Dogs in Different Environmental Conditions.

The aim of the study was to assess the usefulness of IRT measurements of selected regions of interest (ROI), i.e., the eyeball and the nose of whippet dogs, before and after coursing competitions taking place in various environmental conditions, thereby enabling the assessment of well-being and the level of heat stress. The research was carried out over two different periods with different thermal humidity indexes (THIs). In the first period, the THI was 59.27 (Run 1), while in the second period, the THI was 63.77 (Run 2). The experimental subjects comprised 111 sighthound-type dogs-whippets-that were photographed with a thermal imaging camera to determine their eye temperature (ET) and nose temperature (NT). The average minimum and maximum eye temperatures were statistically lower after running in both measurements. Increased minimum and maximum nose temperatures were also demonstrated after both runs. The nasal temperature values were statistically higher for Run 2, for which the THI was higher, compared to Run 1. Eyeball temperature may be a marker of thermoregulation ability, regardless of the ambient temperature. The value of ETmax decreased on average by 2.23 °C and 0.4 °C, while NTmax increased uniformly by 2 °C after both runs. A correlation was found between the IRT measurements and physiological indicators.

Automated collection of facial temperatures in dairy cows via improved UNet

In cattle, facial temperatures captured by infrared thermography provide useful information from physiological aspects for researchers and local practitioners. Traditional temperature collection requires massive manual operations on relevant software. Therefore, this paper aimed to propose a tool for automated temperature collection from cattle facial landmarks (i.e., eyes, muzzle, nostrils, ears, and horns). An improved UNet was designed by replacing the traditional convolutional layers in the decoder with Ghost modules and adding Efficient Channel Attention (ECA) modules. The improved model was trained on our open-source cattle infrared image dataset. The results show that Ghost modules reduced computational complexity and ECA modules further improved segmentation performance. The improved UNet outperformed other comparable models on the testing set, with the highest mean Intersection of Union of 80.76% and a slightly slower but still good inference speed of 32.7 frames per second. Further agreement analysis reveals small to negligible differences between the temperatures obtained automatically in the areas of eyes and ears and the ground truth. Collectively, this study demonstrates the capacity of the proposed method for automated facial temperature collection in cattle infrared images. Further modelling and correction with data collected in more complex conditions are required before it can be integrated into on-farm monitoring of animal health and welfare.

Prediction of occupant thermal state via infrared thermography and explainable AI

Accurate and real-time assessment of occupant thermal comfort can provide a solid foundation for efficient air conditioning operations. Existing studies already show the feasibility of using contactless technologies for thermal comfort prediction assisted by machine learning algorithms. However, the lack of transparency in machine learning often weakens user trust. This study performs explainable AI analysis to explore the potential of infrared imaging in thermal comfort evaluation. Specifically, an investigation was carried out in a climatic chamber, and infrared cameras were used to collect facial temperature data. Five popular ensemble tree models were employed to construct prediction models, and explainable AI analysis was performed using SHAP (SHapley Additive exPlanations) theory. Results show that combining additional facial information can significantly improve the overall model performance, and certain facial attributes present high contributions based on SHAP values. Combining facial features with explainable AI provides a convincing basis for thermal comfort assessment. The high SHAP values of facial features can also contribute to finding selective occupants with low neutral voting rates, providing evidence for customized cooling or heating from building systems.

Prediction of coronary artery disease based on facial temperature information captured by non-contact infrared thermography

BackgroundCurrent approaches for initial coronary artery disease (CAD) assessment rely on pretest probability (PTP) based on risk factors and presentations, with limited performance. Infrared thermography (IRT), a non-contact technology that...

Your blush gives you away: detecting hidden mental states with remote photoplethysmography and thermal imaging.

Multimodal emotion recognition techniques are increasingly essential for assessing mental states. Image-based methods, however, tend to focus predominantly on overt visual cues and often overlook subtler mental state changes. Psychophysiological research has demonstrated that heart rate (HR) and skin temperature are effective in detecting autonomic nervous system (ANS) activities, thereby revealing these subtle changes. However, traditional HR tools are generally more costly and less portable, while skin temperature analysis usually necessitates extensive manual processing. Advances in remote photoplethysmography (r-PPG) and automatic thermal region of interest (ROI) detection algorithms have been developed to address these issues, yet their accuracy in practical applications remains limited. This study aims to bridge this gap by integrating r-PPG with thermal imaging to enhance prediction performance. Ninety participants completed a 20-min questionnaire to induce cognitive stress, followed by watching a film aimed at eliciting moral elevation. The results demonstrate that the combination of r-PPG and thermal imaging effectively detects emotional shifts. Using r-PPG alone, the prediction accuracy was 77% for cognitive stress and 61% for moral elevation, as determined by a support vector machine (SVM). Thermal imaging alone achieved 79% accuracy for cognitive stress and 78% for moral elevation, utilizing a random forest (RF) algorithm. An early fusion strategy of these modalities significantly improved accuracies, achieving 87% for cognitive stress and 83% for moral elevation using RF. Further analysis, which utilized statistical metrics and explainable machine learning methods including SHapley Additive exPlanations (SHAP), highlighted key features and clarified the relationship between cardiac responses and facial temperature variations. Notably, it was observed that cardiovascular features derived from r-PPG models had a more pronounced influence in data fusion, despite thermal imaging's higher predictive accuracy in unimodal analysis.

Effect of face masks on dyspnea perception, cardiopulmonary parameters, and facial temperature in healthy adults.

Respiratory droplets, naturally produced during expiration, can transmit pathogens from infected individuals. Wearing a face mask is crucial to prevent such transmission, yet the perception of dyspnea and uncomfortable breathing remains a common concern, particularly during epidemics. The aim of this study was to investigate the impact of face mask use on the perception of dyspnea, cardiopulmonary parameters, and facial temperature during physical activity. A randomized crossover study was conducted on healthy adults at a physiology laboratory located in the Faculty of Medicine, Universitas Sumatera Utara, Medan, Indonesia, in November 2022. Participants underwent five stages of physical exercise tests based on the Bruce Protocol under three conditions: without any face mask (control), wearing a surgical mask, and an N95 mask, forming the study's main groups. Dyspnea perception (measured by the Modified Borg Dyspnea Scale), cardiopulmonary parameters (heart rate, oxygen saturation, respiratory rate, blood pressure, and mean arterial pressure) and facial temperature were measured before the exercise test (pre-workout), at the end of stage 1, 2, 3, 4, 5, and after the whole exercise test (post-workout). A two-way repeated measures ANOVA was conducted, considering two factors: the type of mask (control, surgical mask, N95 mask) and the various stages of the exercise test. A total of 36 healthy adults were included in the study. We found that dyspnea perception was much worse in the N95 mask group, particularly during vigorous exercise. There was no significant difference between groups in cardiopulmonary parameters. However, participants wearing N95 had a greater supralabial temperature than those wearing surgical masks or no mask at all. It is recommended to undertake a more in-depth evaluation of cardiopulmonary physiological measures.

Analysis of autonomic responses during transnasal cooling via facial temperature and heart rate monitoring

Introduction Transnasal cooling has been shown to improve symptoms in patients with migraine headaches in a recent clinical trial. However, the mechanism underlying this phenomenon is unclear. Methods We sought to explore the potential autonomic responses to transnasal cooling in 10 patients by measuring changes in facial temperature and heart rate. Results We observed a decrease in average facial temperatures at the end of intervention compared to baseline in all regions measured, namely the forehead (−0.55 ± 0.58°F, p = 0.007), the opposite cheek (−0.44 ± 0.34°F, p = 0.027), and the same cheek (−0.64 ± 0.91°F, p = 0.001). The average baseline heart rate was 70.1 ± 10.5 bpm and did not undergo a change throughout the three phases (p = 0.22). Conclusion Bilateral facial temperature reduction despite unilateral cooling, prolonged cooling effect post-intervention, and no significant change in heart rate suggest a local sympathetic response to transnasal cooling.

Toward Objectification of Subjective Chronic Pain based on Implicit Response in Biosignals.

Chronic pain necessitates early intervention and accurate evaluation. Current subjective questionnaire -based methods have limitations. This study aims to develop a chronic pain assessment method based on multi-modal biosignal and to validate its feasibility. We present a model utilizing electroencephalogram (EEG), photoplethysmogram (PPG), electrocardiogram (ECG), and facial temperature (FT) data from 59 subjects (26 chronic pain patients). A total of 112 features were derived from all signals, and 17 of them showed a significant difference between the chronic pains and the normal control. By optimizing signal types and feature combinations, our pain classification model significantly enhanced chronic pain assessment (AUROC: 0.802 to 0.864). Notable features included PPG systolic length (12.3%), EEG alpha band power (11.1%), and delta band power (9.4%). This multi-modal biosignal approach holds promise for effective chronic pain quantification.

An Empirical Study of the Value of the Change in the Facial Temperature of a Suspect in a Simulated Theft Case in the State of Lies

An Empirical Study of the Value of the Change in the Facial Temperature of a Suspect in a Simulated Theft Case in the State of Lies

Non-Contact Thermal and Acoustic Sensors with Embedded Artificial Intelligence for Point-of-Care Diagnostics.

This work involves exploring non-invasive sensor technologies for data collection and preprocessing, specifically focusing on novel thermal calibration methods and assessing low-cost infrared radiation sensors for facial temperature analysis. Additionally, it investigates innovative approaches to analyzing acoustic signals for quantifying coughing episodes. The research integrates diverse data capture technologies to analyze them collectively, considering their temporal evolution and physical attributes, aiming to extract statistically significant relationships among various variables for valuable insights. The study delineates two distinct aspects: cough detection employing a microphone and a neural network, and thermal sensors employing a calibration curve to refine their output values, reducing errors within a specified temperature range. Regarding control units, the initial implementation with an ESP32 transitioned to a Raspberry Pi model 3B+ due to neural network integration issues. A comprehensive testing is conducted for both fever and cough detection, ensuring robustness and accuracy in each scenario. The subsequent work involves practical experimentation and interoperability tests, validating the proof of concept for each system component. Furthermore, this work assesses the technical specifications of the prototype developed in the preceding tasks. Real-time testing is performed for each symptom to evaluate the system's effectiveness. This research contributes to the advancement of non-invasive sensor technologies, with implications for healthcare applications such as remote health monitoring and early disease detection.

Reactivity of observers' facial skin blood flow depending on others' facial expressions and blushing.

Facial skin blood flow (SkBF) has attracted attention as an autonomic indicator because it influences facial colour, which informs others of emotional states, and facial temperature related to social anxiety. Previous studies have examined the facial SkBF in people experiencing emotions; however, facial SkBF changes in the observers of emotions are poorly understood. Our study clarified facial SkBF changes related to observing others' emotions by comparing the changes with other physiological indices. Thirty healthy participants (24 females; mean age: 22.17) observed six types of facial expressions (neutral, angry, and embarrassed expressions with and without facial blushing) and rated the emotional intensity of the other person. We measured their facial SkBF, finger SkBF, and cardiac RR interval as they made their observations. Facial SkBF generally decreased in relation to observing emotional faces (angry and embarrassed faces) and significantly decreased for angry expressions with blushing. None of the participants noticed blushing of facial stimuli. For the RR interval and finger SkBF, there was no variation depending on the observed facial expressions, although there was a general increase related to observation. These results indicated that facial SkBF is sensitive and reactive to emotional faces-especially angry faces with blushing- compared with other autonomic indices. The facial SkBF changes were not related to either RR interval changes or the intensity rating, suggesting that facial SkBF changes may be caused by vasoconstriction and have potential functions for our emotions. The decrease in facial SkBF may have a role in calming observers by preventing them from adopting the same emotional state as a person with intense anger. These findings clarify daily facial SkBF fluctuations and their relationship with our emotional processing in interpersonal situations.