Forehead Temperature Research Articles

The facial expression of schizophrenic patients applied with infrared thermal facial image sequence

BackgroundSchizophrenia is a neurological disease characterized by alterations to patients’ cognitive functions and emotional expressions. Relevant studies often use magnetic resonance imaging (MRI) of the brain to explore structural differences and responsiveness within brain regions. However, as this technique is expensive and commonly induces claustrophobia, it is frequently refused by patients. Thus, this study used non-contact infrared thermal facial images (ITFIs) to analyze facial temperature changes evoked by different emotions in moderately and markedly ill schizophrenia patients.MethodsSchizophrenia is an emotion-related disorder, and images eliciting different types of emotions were selected from the international affective picture system (IAPS) and presented to subjects during ITFI collection. ITFIs were aligned using affine registration, and the changes induced by small irregular head movements were corrected. The average temperatures from the forehead, nose, mouth, left cheek, and right cheek were calculated, and continuous temperature changes were used as features. After performing dimensionality reduction and noise removal using the component analysis method, multivariate analysis of variance and the Support Vector Machine (SVM) classification algorithm were used to identify moderately and markedly ill schizophrenia patients.ResultsAnalysis of five facial areas indicated significant temperature changes in the forehead and nose upon exposure to various emotional stimuli and in the right cheek upon evocation of high valence low arousal (HVLA) stimuli. The most significant P-value (lower than 0.001) was obtained in the forehead area upon evocation of disgust. Finally, when the features of forehead temperature changes in response to low valence high arousal (LVHA) were reduced to 9 using dimensionality reduction and noise removal, the identification rate was as high as 94.3%.ConclusionsOur results show that features obtained in the forehead, nose, and right cheek significantly differed between moderately and markedly ill schizophrenia patients. We then chose the features that most effectively distinguish between moderately and markedly ill schizophrenia patients using the SVM. These results demonstrate that the ITFI analysis protocol proposed in this study can effectively provide reference information regarding the phase of the disease in patients with schizophrenia.

Effect ofWBGT on body thermal responses for agricultural workers in Southern Rajasthan, India

Rajasthan state is in west region of India. Maximum temperatures rise sharply exceeding 45° C by the end of May and early June resulting in harsh summers in the state. Heat stress is a condition that is caused by worker over-exposure to the high temperature work environments often found in outdoor agriculture operations. Wet Bulb Globe Temperature (WBGT) is a measure of heat stress. Considering the range of temperatures prevalent in the Rajasthan state during the months of May and June, agricultural operations during these months and the associated heat stress on the agricultural workers, this study was designed to ascertain the effect of WBGT on body thermal responses of agricultural workers. Southern Rajasthan was selected to conduct this study. The study was conducted on 12 farm workers. Different WBGT of 28°C, 29°C, 30°C, 31°C and 32°C were selected for this study. Thermal parameters included head, forehead and oral temperature. Forehead temperature was observed to decrease with an increase in WBGT. Heavy sweating was observed at high WBGT and this resulted in the decrease in skin and forehead temperature. Oral and head temperature was observed to increase with increase in WBGT. Since oral temperature is also considered to be the core temperature of body, it increased with increase in WBGT. Head absorbs the direct solar radiations and hence, its temperature increased with increase in WBGT.

Face Cooling Increases Blood Pressure during Simulated Blood Loss

IntroductionBlood loss causes central hypovolemia and in severe instances, it can decrease blood pressure and lead to cardiovascular decompensation. Simple and quick interventions that can be used to prevent cardiovascular decompensation in pre‐hospital settings could be a valuable tool for first responsders. Cooling the forehead and cheeks using an ice/water slurry mixture has been shown to increase blood pressure for over 15 minutes. Therefore, face cooling could be used to mitigate decreases in blood pressure during blood loss.PurposeWe tested the hypothesis that face cooling during simulated blood loss will increase blood pressure.MethodsTen healthy participants (22 ± 2 years, 3 women) completed two randomized trials on separate days. Both trials began with 30 mmHg of lower body negative pressure (LBNP) to simulate blood loss for 6 minutes. Then, either a 2.5 L plastic bag of an ice/water slurry mixture (0 ± 0°C) (LBNP+FC) or a 2.5 L plastic bag of thermoneutral water (34 ± 1°C) (LBNP+SHAM) was placed on the forehead and eyes and 30 mmHg of LBNP was maintained for an additional 15 minutes. We continuously measured blood pressure (Penaz method), heart rate (ECG), stroke volume (Model flow), cardiac output, total peripheral resistance, and forehead temperature throughout the protocol.ResultsForehead temperature did not change from LBNP (34.2 ± 0.6°C) to LBNP+SHAM (33.9 ± 1.4°C, P > 0.999) and decreased from LBNP (34.4 ± 0.5°C) to LBNP+FC (11.0 ± 1.6°C, P < 0.001). Mean arterial pressure did not change from LBNP (82 ± 10 mmHg) to LBNP+SHAM (80 ± 8 mmHg, P = 0.978), but markedly increased during LBNP+FC. The peak increase from LBNP (77 ± 9 mmHg) was observed after 3 minutes of LBNP+FC (98 ± 15 mmHg, P < 0.001). Heart rate during LBNP (76 ± 14 bpm, P = 0.978) was not different from LBNP+SHAM (75 ± 13 bpm). Heart rate was lower throughout LBNP+FC beginning at 2 minutes of FC (60 ± 16 bpm) versus LBNP (80 ± 19 bpm, P < 0.001). Stroke volume did not change from LBNP (72 ± 15 mL) to LBNP+SHAM (67 ± 18 mL, P = 0.857). However, stroke volume increased from LBNP (78 ± 16 mL) to LBNP+FC, and peaked after 5 minutes of FC (97 ± 32 mL, P < 0.001). Cardiac output did not change from LBNP (5.4 ± 1.0 L/min) to LBNP+SHAM (4.9 ± 1.0 L/min, P > 0.415). Cardiac output slightly decreased from LBNP (6.2 ± 1.5 L/min) to 2 minutes of LBNP+FC (5.3 ± 1.6 L/min, P = 0.038). Total peripheral resistance did not change from LBNP (15.6 ± 3.7 mmHg/L/min) to LBNP+SHAM (17.3 ± 3.2 mmHg/L/min, P = 0.613). Total peripheral resistance throughout LBNP+FC was greater than LBNP. The peak increase in total peripheral resistance was observed after 2 minutes of LBNP+FC (20.0 ± 6.2 mmHg/L/min) versus LBNP (13.2 ± 3.9 mmHg/L/min, P < 0.001).ConclusionsFace cooling during simulated moderate blood loss increases blood pressure through an increase in total peripheral resistance. Although more research is warranted, face cooling during blood loss is a potential simple and quick intervention that could delay cardiovascular decompensation.Support or Funding InformationUniversity at Buffalo IMPACT Award

Real-Time Monitoring of Occupants’ Thermal Comfort through Infrared Imaging: A Preliminary Study

Thermally comfortable indoor environments are of great importance, as modern lifestyles often require people to spend more than 20 h per day indoors. Since most of the thermal comfort models use a variety of different environmental and personal factors that need to be measured or estimated, real-time and continuous assessment of thermal comfort is often not practically feasible. This work presents a cheap and non-invasive approach based on infrared imaging for monitoring the occupants’ thermal sensation and comfort in real time. Thanks to a mechatronic device developed by the authors, the imaging is performed on the forehead skin, selected because it is always exposed to the environment and, thus, facilitating the monitoring activity in a non-invasive manner. Tests have been performed in controlled conditions on ten subjects to assess the hypothesis that the forehead temperature is correlated with subjects’ thermal sensation. This allows the exploitation of this quantity as a base for a simple monitoring of thermal comfort, which could later be tuned with an extensive experimental campaign.

Mapping the body surface temperature of cattle by infrared thermography

Infrared thermography (IRT) is an alternative non-invasive method that has been studied as a tool for identifying many physiological and pathological processes related to changes in body temperature. The objective of the present study was to evaluate the body surface temperature of Jersey dairy cattle in a thermoneutral environment in order to contribute to the determination of a body surface temperature pattern for animals of this breed in a situation of thermal comfort. Twenty-four Jersey heifers were used over a period of 35 days at APTA Brazil. Measurements were performed on all animals, starting with the physiological parameters. Body surface temperature was measured by IRT collecting images in different body regions: left and right eye area, right and left eye, caudal left foreleg, cranial left foreleg, right and left flank, and forehead. High correlations were observed between temperature and humidity index (THI) and right flank, left flank and forehead temperatures (0.85, 0.81, and 0.81, respectively). The IRT variables that exhibited the five highest correlation coefficients in principal component 1 were, in decreasing order: forehead (0.90), right flank (0.87), left flank (0.84), marker 1 caudal left foreleg (0.83), marker 2 caudal left foreleg (0.74). The THI showed a high correlation coefficient (0.88) and moderate to low correlations were observed for the physiological variables rectal temperature (0.43), and respiratory frequency (0.42). The thermal profile obtained indicates a surface temperature pattern for each region studied in a situation of thermal comfort and may contribute to studies investigating body surface temperature. Among the body regions studied, IRT forehead temperature showed the highest association with rectal temperature, and forehead and right and left flank temperatures are strongly associated with THI and may be adopted in future studies on thermoregulation and body heat production.

Circadian rhythms in bed rest: Monitoring core body temperature via heat-flux approach is superior to skin surface temperature

ABSTRACTContinuous recordings of core body temperature (CBT) are a well-established approach in describing circadian rhythms. Given the discomfort of invasive CBT measurement techniques, the use of skin temperature recordings has been proposed as a surrogate. More recently, we proposed a heat-flux approach (the so-called Double Sensor) for monitoring CBT. Studies investigating the reliability of the heat-flux approach over a 24-hour period, as well as comparisons with skin temperature recordings, are however lacking. The first aim of the study was therefore to compare rectal, skin, and heat-flux temperature recordings for monitoring circadian rhythm. In addition, to assess the optimal placement of sensor probes, we also investigated the effect of different anatomical measurement sites, i.e. sensor probes positioned at the forehead vs. the sternum. Data were collected as part of the Berlin BedRest study (BBR2-2) under controlled, standardized, and thermoneutral conditions. 24-hours temperature data of seven healthy males were collected after 50 days of -6° head-down tilt bed-rest. Mean Pearson correlation coefficients indicated a high association between rectal and forehead temperature recordings (r > 0.80 for skin and Double Sensor). In contrast, only a poor to moderate relationship was observed for sensors positioned at the sternum (r = -0.02 and r = 0.52 for skin and Double Sensor, respectively). Cross-correlation analyses further confirmed the feasibility of the forehead as a preferred monitoring site. The phase difference between forehead Double Sensor and rectal recordings was not statistically different from zero (p = 0.313), and was significantly smaller than the phase difference between forehead skin and rectal temperatures (p = 0.016). These findings were substantiated by cosinor analyses, revealing significant differences for mesor, amplitude, and acrophase between rectal and forehead skin temperature recordings, but not between forehead Double Sensor and rectal temperature measurements. Finally, Bland-Altman analysis indicated narrower limits of agreement for rhythm parameters between rectal and Double Sensor measurements compared to between rectal and skin recordings, irrespective of the measurement site (i.e. forehead, sternum). Based on these data we conclude that (1) Double Sensor recordings are significantly superior to skin temperature measurements for non-invasively assessing the circadian rhythm of rectal temperature, and (2) temperature rhythms from the sternum are less reliable than from the forehead. We suggest that forehead Double Sensor recordings may provide a surrogate for rectal temperature in circadian rhythm research, where constant routine protocols are applied. Future studies will be needed to assess the sensor’s ecological validity outside the laboratory under changing environmental and physiological conditions.

Multi-sector thermo-physiological head simulator for headgear research.

A novel thermo-physiological human head simulator for headgear testing was developed by coupling a thermal head manikin with a thermo-physiological model. As the heat flux at head-site is directly measured by the head manikin, this method provides a realistic quantification of the heat transfer phenomena occurring in the headgear, such as moisture absorption-desorption cycles, condensation, or moisture migration across clothing layers. Before coupling, the opportunities of the head manikin for representing the human physiology were evaluated separately. The evaluation revealed reduced precision in forehead and face temperature predictions under extreme heterogeneous temperature distributions and no initial limitation for simulating temperature changes observed in the human physiology. The thermo-physiological model predicted higher sweat rates when applied for coupled than for pure virtual simulations. After coupling, the thermo-physiological human head simulator was validated using eight human experiments. It precisely predicted core, mean skin, and forehead temperatures with average rmsd values within the average experimental standard deviation (rmsd of 0.20 ± 0.15, 0.83 ± 0.34, and 1.04 ± 0.54°C, respectively). However, in case of forehead, precision was lower for the exposures including activity than for the sedentary exposures. The representation of the human sweat evaporation could be affected by a reduced evaporation efficiency and the manikin sweat dynamics. The industry will benefit from this thermo-physiological human head simulator leading to the development of helmet designs with enhanced thermal comfort and, therefore, with higher acceptance by users.

A Comparison of Mixed-Method Cooling Interventions on Preloaded Running Performance in the Heat.

Stevens, CJ, Bennett, KJM, Sculley, DV, Callister, R, Taylor, L, and Dascombe, BJ. A comparison of mixed-method cooling interventions on preloaded running performance in the heat. J Strength Cond Res 31(3): 620-629, 2017-The purpose of this investigation was to assess the effect of combining practical methods to cool the body on endurance running performance and physiology in the heat. Eleven trained male runners completed 4 randomized, preloaded running time trials (20 minutes at 70% V[Combining Dot Above]O2max and a 3 km time trial) on a nonmotorized treadmill in the heat (33° C). Trials consisted of precooling by combined cold-water immersion and ice slurry ingestion (PRE), midcooling by combined facial water spray and menthol mouth rinse (MID), a combination of all methods (ALL), and control (CON). Performance time was significantly faster in MID (13.7 ± 1.2 minutes; p < 0.01) and ALL (13.7 ± 1.4 minutes; p = 0.04) but not PRE (13.9 ± 1.4 minutes; p = 0.24) when compared with CON (14.2 ± 1.2 minutes). Precooling significantly reduced rectal temperature (initially by 0.5 ± 0.2° C), mean skin temperature, heart rate and sweat rate, and increased iEMG activity, whereas midcooling significantly increased expired air volume and respiratory exchange ratio compared with control. Significant decreases in forehead temperature, thermal sensation, and postexercise blood prolactin concentration were observed in all conditions compared with control. Performance was improved with midcooling, whereas precooling had little or no influence. Midcooling may have improved performance through an attenuated inhibitory psychophysiological and endocrine response to the heat.

Sustained increases in blood pressure elicited by prolonged face cooling in humans.

We tested the hypothesis that increases in blood pressure are sustained throughout 15 min of face cooling. Two independent trials were carried out. In the Face-Cooling Trial, 10 healthy adults underwent 15 min of face cooling where a 2.5-liter bag of ice water (0 ± 0°C) was placed over their cheeks, eyes, and forehead. The Sham Trial was identical except that the temperature of the water was 34 ± 1°C. Primary dependent variables were forehead temperature, mean arterial pressure, and forearm vascular resistance. The square root of the mean of successive differences in R-R interval (RMSSD) provided an index of cardiac parasympathetic activity. In the Face Cooling Trial, forehead temperature fell from 34.1 ± 0.9°C at baseline to 12.9 ± 3.3°C at the end of face cooling (P < 0.01). Mean arterial pressure increased from 83 ± 9 mmHg at baseline to 106 ± 13 mmHg at the end of face cooling (P < 0.01). RMSSD increased from 61 ± 40 ms at baseline to 165 ± 97 ms during the first 2 min of face cooling (P ≤ 0.05), but returned to baseline levels thereafter (65 ± 49 ms, P ≥ 0.46). Forearm vascular resistance increased from 18.3 ± 4.4 mmHg·ml-1·100 g tissue-1·min at baseline to 26.6 ± 4.0 mmHg·ml-1·100 g tissue-1·min at the end of face cooling (P < 0.01). There were no changes in the Sham Trial. These data indicate that increases in blood pressure are sustained throughout 15 min of face cooling, and face cooling elicits differential time-dependent parasympathetic and likely sympathetic activation.

Vital sign monitoring utilizing Eulerian video magnification and thermography.

In this paper we present a proof of concept for non-contact extraction of vital signs using RGB and thermal images obtained from a smart phone. Using our method, heart rate, respiratory rate and forehead temperature can be measured concurrently. Face detection and tracking is leveraged in order to allow natural motion of patients. Heart rate is estimated via processing of visible band RGB video using Eulerian Video Magnification technique. Respiratory rate and the temperature is measured using thermal video. Experiments conducted with 11 healthy subjects indicate that heart rate and respiration rate can be measured with 92 and 94 percent accuracy, respectively.

Running performance in the heat is improved by similar magnitude with pre-exercise cold-water immersion and mid-exercise facial water spray

ABSTRACTThis investigation compared the effects of external pre-cooling and mid-exercise cooling methods on running time trial performance and associated physiological responses. Nine trained male runners completed familiarisation and three randomised 5 km running time trials on a non-motorised treadmill in the heat (33°C). The trials included pre-cooling by cold-water immersion (CWI), mid-exercise cooling by intermittent facial water spray (SPRAY), and a control of no cooling (CON). Temperature, cardiorespiratory, muscular activation, and perceptual responses were measured as well as blood concentrations of lactate and prolactin. Performance time was significantly faster with CWI (24.5 ± 2.8 min; P = 0.01) and SPRAY (24.6 ± 3.3 min; P = 0.01) compared to CON (25.2 ± 3.2 min). Both cooling strategies significantly (P < 0.05) reduced forehead temperatures and thermal sensation, and increased muscle activation. Only pre-cooling significantly lowered rectal temperature both pre-exercise (by 0.5 ± 0.3°C; P < 0.01) and throughout exercise, and reduced sweat rate (P < 0.05). Both cooling strategies improved performance by a similar magnitude, and are ergogenic for athletes. The observed physiological changes suggest some involvement of central and psychophysiological mechanisms of performance improvement.

Physiological response of locusts to eye stimulation by spectral illumination for phototactic pest control

To provide theoretical support for study of locust phototactic vision nature, the locust phototactic physiology and visual spectrum effects were investigated by stimulating the visual system using light from an AvaSpec fiber-optic spectrometer and Flir thermal imaging system. When light stimulated the locust visual system, the biological photoelectric transformation effect of the visual system caused by photon energy, presented with the higher physiological temperature on the forehead, as tested by the Flir thermal system. After stimulation with light, the different absorption degrees of the vision system on the spectral photons, as tested by the AvaSpec spectrometer, showed that the phototactic response to light had the simultaneous requirements of lighting intensity and time. The absorbing differences of spectral photons by the vision system demonstrated the absorption selectivity under light stimulation, as exhibited by the sensitive absorption of spectral energy at 430 nm, 545 nm and 615 nm. Moreover, the higher forehead temperature increment indicated and induced the stronger physiology activity which was the reason that causing the good phototactic response degree of locusts with 30 min light stimulation, and the adaption time was about 60 min. Therefore, only when the visual reaction effect was stimulated to absorb sensitive spectral energy and generate the physiological exciting response could cause the phototactic behavior. Keywords: Phototactic pest control, physiological response, Locusta migratoria, spectral illumination, phototactic vision, spectrum absorption, light simulation DOI: 10.3965/j.ijabe.20160902.1249 Citation: Liu Q H, Zhou Q. Physiological response of locusts to eye stimulation by spectral illumination for phototactic pest control. Int J Agric & Biol Eng, 2016; 9(2): 186－194.

족욕프로그램이 뇌졸중 환자의 심박변이도, 혈압, 체온 및 피로에 미치는 효과

Purpose: This study was to examine the effects of a footbath program on heart rate variability, blood pressure, body temperature and fatigue of stroke patients with stroke-induced hemiparesis. Methods: A non-equivalent control group pretest-posttest design was used. Participants were 40 stroke patients, twenty for the footbath program and twenty for the control group, who were hospitalized in a long-term rehabilitation hospital in G city of Korea, from February to April 2014. The twenty participants in the experimental group received the intervention of footbaths and an educational program focused on the prevention of stroke complications; Collected data were analyzed by the IBM SPSS WIN 20.0 program using a t-test, χ² test, Mann-Whitney U test and repeated measures ANOVA. Results: Significant differences were found in heart rate variability, systolic blood pressure, hand and foot temperatures and fatigue between the two groups. But no significant differences were found in diastolic blood pressure, core temperatures, forehead temperatures, and hand temperatures between the two groups. Conclusion: The footbath program was an effective intervention for skin temperature change and fatigue reduction for stroke patients. Therefore, it is recommended that the footbath program can be utilized as an effective nursing intervention for stroke patients in long-term rehabilitation care hospitals.

Clinical accuracy of non-contact infrared thermometer from umbilical region in children: A new side

Measurement from axillary site with digital thermometer has been accepted as the most accurate method. But this method is time consuming. Tympanic and forehead measurements are often used but don't always seem to be more appropriate. Another site, umbilical region, could be an alternative site. This study aims to compare the measurements with axillary digital thermometer and non-contact infrared thermometers at sites from umbilicus and forehead to determine whether umbilical site could be used accurately in children. For each method, 2,048 measurements in total were performed. Using axillary method as gold standard, with a cut-off temperature of 38oC, the sensitivities and specificities, positive and negative predictive values of umbilical and forehead temperatures and area under the ROC curve were determined in non obese children. There was a significant positive correlation between axillary and umbilical temperatures with a correlation coefficient of 0.78. The average difference between the mean of both axillary and umbilical temperatures was -0.47 ± 0.65°C. The Bland-Altman plot showed good accuracy with only 2.5 % of the readings falling outside the 95% level of confidence. Umbilical measurements showed sensitivity of 71.7% and specificity of 95.8%. The area under the ROC curve was 0.93. The easy application may lead noncontact measurements from umbilicus site to be the preferable method for health care providers, but agreement limits mentioned in this study should be considered.

Newborn friendly thermometry – Comparative study of body temperature with an infrared versus digital thermometer

Background: Accurate measurement of body temperature is of great importance in day to day neonatology practice. One touch infrared thermometry is safe, accurate, and easy to use. Objective: We aimed at comparing infrared forehead thermometer with an axillary digital thermometer to assess the accuracy. Methods: Axillary and forehead temperatures were measured simultaneously in normal newborn babies using digital and infrared thermometers respectively at a tertiary level teaching hospital in northern Kerala, India and the meantemperature measured by these two methods were compared. Those babies with fever or admitted at Neonatal Intensive Care Unit were not included in the study. Results: Totally, 193 newborns were included in the study with the mean birth weight of 2600±400 g. There was no significant difference in temperature measured by digital and infrared thermometers (97.74±0.91°F vs. 97.81±0.89°F, p=0.44). There was a significant positive correlation between axillary and forehead temperature (r=0.94) and mean difference between two readingswas 0.07±0.25°F (p=0.11). Conclusion: Infrared forehead thermometry is as reliable and accurate as axillary digital thermometry. Thus, infrared forehead thermometry can be used in clinical practice, especially in neonatal and postnatal wards where ease of use and speed of obtaining the temperature readings are important.

光生物节律因子计算模型的研究

Two kinds of model,Biological Equivalent model and Circadian Light model which used to evaluate the biological effect of light were discassed and the differences between them were pointed out by fitting curve between the biorhythm factor and human body temperature after several field test.Calculating with the spectrum produced by the LCD screen,it shows that these two models have a stronger restraint of green light band while the red band of light appear not too consistent with the actual results.By tested the forehead temperature under different colors of LED light and fitting with the calculated biorhythm factor,it demonstrates that the forehead temperature increases with the biorhythm factor linearly.And the linear fitting correlation of biological equivalent model is 0.95.

Comparative study of circadian variation in oral, tympanic, forehead, axillary and elbow pit temperatures measured in a cohort of young university students living their normal routines

The primary objective of the present research work is to study and compare the circadian variability in body temperature recorded from different locations of the body during subjects’ normal routines. Temperatures of oral cavity (sublingually), tympanum, forehead, axilla and the elbow pit were measured simultaneously at approximate 1-h intervals for five consecutive days during subjects’ waking span in their routine living condition. The observations were made in eight young, apparently healthy, university students. Data were analysed using cosinor rhythmometry for evaluation of circadian rhythms and two-way ANOVA with repeated measures to assess the effect of time of day and measuring site on body temperatures and their interaction. Significant circadian rhythms in body temperature, irrespective of site, were found. Based on autocorrelation analysis, it was observed that the day-to-day variability in body temperature was consistent. The acrophases of all the studied temperature rhythms were located in the afternoon, except axillary temperature, which occurred in the early evening. The mean daytime temperature was found to be the highest when recorded sublingually and it was the lowest on the forehead or elbow pit. On the basis of the results of this study, we recommend that the methods used could be introduced into laboratory courses in a curriculum of chronobiology courses for both UG and PG classes for the demonstration/study of circadian rhythms in body temperature under normal routines. The methods used are valuable as they are non-invasive, easily accepted and assessable in a student setting.

Changes in serum free testosterone, sleep patterns, and 5-alpha-reductase type I activity influence changes in sebum excretion in female subjects.

Sebum is thought to play an important role in acne vulgaris and sebum excretion rate (SER) is often used as a marker of efficacy in acne studies. This study explored factors that could induce intra-subject variability in SER. SER was measured twice, 7 days apart, on the forehead of 40 healthy subjects. At each visit, the following parameters were also evaluated: serum androgen levels, 5-alpha-reductase type I gene expression, forehead temperature, sleep habits, diet, facial washing routine, and UV exposure. There was a positive correlation between the time subjects fell asleep on Day 0 and the change in SER for the left (P=0.010; R=0.402) and right sides (P=0.002; R=0.467) of the forehead. There was a significant inverse correlation between SER and 5-alpha-reductase type 1 expression and between free testosterone levels and 5-alpha-reductase type 1 expression. In sub-analyses performed on men and women, these correlations were only significant for women. Variations in sleep patterns, free testosterone, and 5-alpha-reductase type 1 activity are associated with changes in sebum excretion in women. This could explain some of the inter-subject variability in SER measured between visits in clinical studies.

Relationships between facial temperature changes, end-exercise affect and during-exercise changes in affect: A preliminary study

The present study was performed as an evaluation of the relationships between changes in facial temperature and self-reported pleasure–displeasure during an acute aerobic exercise bout. Ninety-two students performed a 10-minute long session of cycle ergometry at 80–85% of age-predicted maximal heart rate. Using infrared thermography and a single-item measure of pleasure–displeasure (the Feeling Scale, FS), facial temperature and the FS score were sampled at the beginning (Min1:00) and at the end of the exercise session (Min9:00). Statistical analyses revealed that cheek (but not forehead) temperature was higher at the end of the exercise bout compared to Min1:00 (it increased by about 5%). Change in cheek temperature was negatively related to end-exercise affect (β = −0.28, P < 0.001) and to during-exercise affective changes (β = −0.35, P < 0.001). No significant relationship with forehead temperature was found. Some of the possible reasons for this differential effect as well as theoretical and practical implications of our findings are discussed.

Evaluation of driver’s mental workload by facial temperature and electrodermal activity under simulated driving conditions

The purpose of this study was to evaluate the mental workload of increasing driving speed, from 60 km/h to 180 km/h, when operating a driving simulator. The evaluation, based on changes in facial temperature and electrodermal activity, showed that the difference between nose and forehead temperature increased, that the skin potential level decreased, and that the skin conductance level increased. Monitoring facial temperature and electrodermal activity were both found to be effective in evaluating the mental workload involved.