scholarly journals Validation of the thermophysiological model by Fiala for prediction of local skin temperatures

2016 ◽  
Vol 60 (12) ◽  
pp. 1969-1982 ◽  
Author(s):  
Natividad Martínez ◽  
Agnes Psikuta ◽  
Kalev Kuklane ◽  
José Ignacio Priego Quesada ◽  
Rosa María Cibrián Ortiz de Anda ◽  
...  
Keyword(s):  
Local Skin ◽  
Thermophysiological Model ◽  
Skin Temperatures

scholarly journals High-Performance Workwear for Coal Miners in Northern China: Design and Performance Evaluation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ying Ke ◽  
Qing Zheng ◽  
Faming Wang ◽  
Min Wang ◽  
Yi Wang
Keyword(s):  
Performance Evaluation ◽  
Thermal Comfort ◽  
High Performance ◽  
Northern China ◽  
Coal Miners ◽  
Climate Chamber ◽  
Local Skin ◽  
Worker Performance ◽  
And Performance ◽  
Skin Temperatures

Abstract The design of workwear has significant effects on worker performance. However, the current workwear for coal miners in Northern China is poor in fitness and thermal comfort. In this study, new workwear (NEW) for coal miners was developed with the design features providing better cold protection and movement comfort performance, as compared with a commonly worn workwear (CON). To evaluate the effectiveness of NEW, we conducted human trials which were performed using simulated work movements (i.e., sitting, shoveling, squatting, and crawling) in a climate chamber (10°C, 75% RH). Physiological measurements and perceptual responses were obtained. The results demonstrated that the local skin temperatures at chest, scapula, thigh, and calf; mean skin temperatures,; and thermal comfort in NEW were significantly higher than those in CON. NEW also exerted an improvement in enhancing movement comfort. We conclude that NEW could meet well with the cold protective and mobility requirements.

Optimization of a neuro-human thermal model using a genetic algorithm

2020 ◽  
pp. 1420326X2097519
Author(s):  
Mohamad El Kadri ◽  
Fabrice De Oliveira ◽  
Christian Inard ◽  
François Demouge
Keyword(s):  
Genetic Algorithm ◽  
Thermal Model ◽  
Absolute Error ◽  
Maximum Error ◽  
Male Students ◽  
Local Skin ◽  
Active Systems ◽  
Physiological Variables ◽  
Human Thermal Model ◽  
Skin Temperatures

A neuro-human thermal model was optimized to increase the prediction accuracy of the physiological variables of a group of 15 healthy male students exposed to transient environmental conditions. The effect of both the passive and active systems parameters was studied using a sensitivity analysis, and the parameters that had the most influence on the neuro-human thermal model outputs were established. A genetic algorithm was then used to optimize the model in order to determine the parameters that corresponded to the studied population. The results showed that the optimization increased the precision of the neuro-human thermal model. The mean absolute error and the maximum error between the experimental data and the numerical results for mean skin temperature were 0.13°C and 0.56°C, respectively, and we obtained 0.03°C and 0.11°C, respectively, for rectal temperature. These results show that the neuro-human thermal model can be accurately adjusted for the rectal, mean and local skin temperatures of a targeted population by using a genetic algorithm to determine the values of the parameters that correspond to this population.

Effects of the cycling workload on core and local skin temperatures

2016 ◽  
Vol 77 ◽  
pp. 91-99 ◽  
Author(s):  
Jose Ignacio Priego Quesada ◽  
Natividad Martínez ◽  
Rosario Salvador Palmer ◽  
Agnes Psikuta ◽  
Simon Annaheim ◽  
...  
Keyword(s):  
Local Skin ◽  
Skin Temperatures

scholarly journals Characteristics of the local cutaneous sensory thermoneutral zone

2017 ◽  
Vol 117 (4) ◽  
pp. 1797-1806 ◽  
Author(s):  
Davide Filingeri ◽  
Hui Zhang ◽  
Edward A. Arens
Keyword(s):  
Steady State ◽  
Skin Temperature ◽  
Thermal State ◽  
Detection Threshold ◽  
Local Skin ◽  
Thermoneutral Zone ◽  
Temperature Detection ◽  
Applied Design ◽  
Skin Temperatures ◽  
Threshold Range

Skin temperature detection thresholds have been used to measure human cold and warm sensitivity across the temperature continuum. They exhibit a sensory zone within which neither warm nor cold sensations prevail. This zone has been widely assumed to coincide with steady-state local skin temperatures between 32 and 34°C, but its underlying neurophysiology has been rarely investigated. In this study we employ two approaches to characterize the properties of sensory thermoneutrality, testing for each whether neutrality shifts along the temperature continuum depending on adaptation to a preceding thermal state. The focus is on local spots of skin on the palm. Ten participants (age: 30.3 ± 4.8 yr) underwent two experiments. Experiment 1 established the cold-to-warm inter-detection threshold range for the palm’s glabrous skin and its shift as a function of 3 starting skin temperatures (26, 31, or 36°C). For the same conditions, experiment 2 determined a thermally neutral zone centered around a thermally neutral point in which thermoreceptors’ activity is balanced. The zone was found to be narrow (~0.98 to ~1.33°C), moving with the starting skin temperature over the temperature span 27.5–34.9°C (Pearson r = 0.94; P < 0.001). It falls within the cold-to-warm inter-threshold range (~2.25 to ~2.47°C) but is only half as wide. These findings provide the first quantitative analysis of the local sensory thermoneutral zone in humans, indicating that it does not occur only within a specific range of steady-state skin temperatures (i.e., it shifts across the temperature continuum) and that it differs from the inter-detection threshold range both quantitatively and qualitatively. These findings provide insight into thermoreception neurophysiology. NEW & NOTEWORTHY Contrary to a widespread concept in human thermoreception, we show that local sensory thermoneutrality is achievable outside the 32–34°C skin temperature range. We propose that sensory adaption underlies a new mechanism of temperature integration. Also, we have developed from vision research a new quantitative test addressing the balance in activity of cutaneous cold and warm thermoreceptors. This could have important clinical (assessment of somatosensory abnormalities in neurological disease) and applied (design of personal comfort systems) implications.

Predicting indoor thermal sensation for the elderly in welfare centres in Korea using local skin temperatures

2016 ◽  
Vol 26 (8) ◽  
pp. 1155-1167 ◽  
Author(s):  
Chihye Bae ◽  
Hyunjung Lee ◽  
Chungyoon Chun
Keyword(s):  
Field Study ◽  
Skin Temperature ◽  
Elderly People ◽  
Thermal Sensation ◽  
The Elderly ◽  
The Body ◽  
Elderly Subjects ◽  
Climate Chamber ◽  
Local Skin ◽  
Skin Temperatures

This study aims to develop a method to predict thermal sensation in elderly people. To identify the point on the body where skin temperature can best predict thermal sensation in elderly people aged 65 or older and develop a thermal comfort measurement model that can replace the psychological scale, experiments were conducted in a stainless steel wall finish climate chamber and at the seven senior welfare centres in Korea. The results of the climate chamber experiment with 30 healthy elderly people (15 males, 15 females) showed that there was a correlation between thermal sensation and local skin temperature on the back of the hand, the upper arm, the top of the foot and the cheek. This developed thermal sensation prediction model was then applied in a field study at senior welfare centres to verify whether the model could be applied to a large number of elderly subjects in different locations. The field study with 294 elderly people (111 males, 183 females) shows that cheek and back of the hand skin temperatures were useful in predicting thermal sensation in the elderly, and predicted thermal sensation based on the skin temperature of the cheek had the strongest correlation with thermal sensation among the participants.

The Effect of Pressure on Skin Temperature Measurements for a Disk Sensor

1979 ◽  
Vol 101 (4) ◽  
pp. 261-266 ◽  
Author(s):  
S. D. Mahanty ◽  
R. B. Roemer
Keyword(s):  
Skin Temperature ◽  
Human Subjects ◽  
Reactive Hyperemia ◽  
Circular Disk ◽  
Temperature Measurements ◽  
Whole Body ◽  
Local Pressure ◽  
Local Skin ◽  
Local Skin Temperature ◽  
Skin Temperatures

In order to determine the effect of application pressure on the accuracy of skin temperature measurements for area contact sensors, low values of pressure (2-20 mm Hg) were applied to the mid-thigh and to the lateral aspect of the trochanter of human subjects using a thin, circular disk with a thermistor mounted in the base. From measurements of the local skin temperatures, it was determined that a pressure of 2 mm Hg is adequate to measure the skin temperature accurately. Applying larger pressure results in higher local skin temperatures with the thighs showing larger temperature increases than the trochanters. The results of a finite difference analysis indicate that the increases in skin temperature at higher pressures can be accounted for by the physical phenomena associated with the penetration of the sensor into the tissue. After the release of pressure, the local skin temperature immediately decreased for all subjects indicating little or no reactive hyperemia was occurring. A method of compensating for the changes in local skin temperature which are due to whole body transient thermal effects was also developed. Use of this method allows the effects of the local pressure application to be separated from the transient environmental effects.

Sweating response in man during transient rises of air temperature

1978 ◽  
Vol 44 (2) ◽  
pp. 284-290 ◽  
Author(s):  
J. P. Libert ◽  
V. Candas ◽  
J. J. Vogt
Keyword(s):  
Rectal Temperature ◽  
Rate Control ◽  
Unsteady State ◽  
Local Skin ◽  
Warm Environment ◽  
Multiplicative Effect ◽  
Transient Period ◽  
Skin Temperatures ◽  
Appreciable Variation ◽  
Stimulation Of

Nude men were exposed to neutral environments (Ta = 28 degrees C, Pw = 20 mbar) changing to warm environments (Ta = 50 degrees C, Pw = 20 mbar). The transient period from neutral to warm environment lasted 4 min (dTA/DT = 5.50 degrees C/min) or 20 min (DTa/dt = 1.10 degrees C/min) or 40 min (dTa/dt = 0.55 degrees C/min) or 60 min (dTa/dt = 0.37 degrees C/min). Continuous measurements were made of rectal and mean skin temperatures and of body weigth loss. Sweating started before appreciable variation in rectal temperature. Onset of sweating could be explained by a peripheral proportional and rate control. Unsteady-state sweating can be predicted by summated stimulation of skin and rectal temperatures. This stimulation could be increased for some subjects by a multiplicative effect due to differences in local skin temperatures. This multiplicative effect occurred during the first transient period.

Experimental Study on Effective Placement of PCM Packets in Cooling Vest to Improve Performance in Warm Environment

2017 ◽  
Author(s):  
Mariam Itani ◽  
Nesreen Ghaddar ◽  
Kamel Ghali ◽  
Beatrice Khater ◽  
Djamel Ouahrani ◽  
...  
Keyword(s):  
Heat Stress ◽  
Perceived Exertion ◽  
Human Subjects ◽  
Whole Body ◽  
Local Cooling ◽  
Coverage Area ◽  
Local Skin ◽  
Gradual Improvement ◽  
Body Cooling ◽  
Skin Temperatures

Global warming has increased the risk of heat stress of outdoor workers and one measure against heat stress is wearing passive personal cooling clothing. Passive body cooling systems, including phase change material (PCM) cooling vests, are considered as an effective solution to improve the working endurance of outdoor active workers. The objective of this study is to assess the effective placement of PCM packets in the cooling vest by examining the local and overall sensation and comfort when: (i) only the frontal segment of the human torso is covered (ii) only the back segment of the human torso is covered and (iii) both segments are covered. The PCM cooling vest is worn by human subjects performing cycling at about 3 Mets and for 30 minutes in a climatic chamber maintained at 28 °C and 60 % relative humidity. The used PCM melting temperature is 28 °C with a coverage area of 642 cm2 and total weight of the vest of 1.19 kg including 8 PCM packets (87.5 grams each). The physiological/thermal responses such as body core and mean skin temperatures, heart rate, and skin wittedness are monitored during the experiments while exercising and wearing the vest. In particular, the frontal and back torso skin temperatures are examined after being subjected to local cooling compared to the case when no PCM packets cover the torso segment. Moreover, subjective votes of thermal comfort, whole body and torso thermal sensations, skin and clothing wetness sensation and perceived exertion are recorded throughout the experiment. The experiment was repeated on five male subjects to ensure robustness of the obtained results. It was found that the core temperature changed slightly when wearing the vest, however the local skin temperature of the back and front torso segments decreased by about 5 °C and 3 °C at the end of the exercise, respectively. Gradual improvement in comfort that reaches a stable level when the PCM starts melting till the end of the exercise was also noticed.

Sign in / Sign up

Export Citation Format

Share Document