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.

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.

scholarly journals Effect of skin temperature on cutaneous vasodilator response to the β-adrenergic agonist isoproterenol

2015 ◽  
Vol 118 (7) ◽  
pp. 898-903 ◽  
Author(s):  
Gary J. Hodges ◽  
Dean L. Kellogg ◽  
John M. Johnson
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Skin Temperature ◽  
Skin Blood Flow ◽  
Local Skin ◽  
Vasodilator Response ◽  
Skin Cooling ◽  
Local Skin Temperature ◽  
Β Receptor ◽  
Skin Temperatures

The vascular response to local skin cooling is dependent in part on a cold-induced translocation of α2C-receptors and an increased α-adrenoreceptor function. To discover whether β-adrenergic function might contribute, we examined whether β-receptor sensitivity to the β-agonist isoproterenol was affected by local skin temperature. In seven healthy volunteers, skin blood flow was measured from the forearm by laser-Doppler flowmetry and blood pressure was measured by finger photoplethysmography. Data were expressed as cutaneous vascular conductance (CVC; laser-Doppler flux/mean arterial blood pressure). Pharmacological agents were administered via intradermal microdialysis. We prepared four skin sites: one site was maintained at a thermoneutral temperature of 34°C (32 ± 10%CVCmax) one site was heated to 39°C (38 ± 11%CVCmax); and two sites were cooled, one to 29°C (22 ± 7%CVCmax) and the other 24°C (16 ± 4%CVCmax). After 20 min at these temperatures to allow stabilization of skin blood flow, isoproterenol was perfused in concentrations of 10, 30, 100, and 300 μM. Each concentration was perfused for 15 min. Relative to the CVC responses to isoproterenol at the thermoneutral skin temperature (34°C) (+21 ± 10%max), low skin temperatures reduced (at 29°C) (+17 ± 6%max) or abolished (at 24°C) (+1 ± 5%max) the vasodilator response, and warm (39°C) skin temperatures enhanced the vasodilator response (+40 ± 9%max) to isoproterenol. These data indicate that β-adrenergic function was influenced by local skin temperature. This finding raises the possibility that a part of the vasoconstrictor response to direct skin cooling could include reduced background β-receptor mediated vasodilation.

Validation of a non-contact technique for local skin temperature measurements

2008 ◽  
Vol 14 (4) ◽  
pp. 381-384 ◽  
Author(s):  
J. George ◽  
A. Bensafi ◽  
A. M. Schmitt ◽  
D. Black ◽  
S. Dahan ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Temperature Measurements ◽  
Local Skin ◽  
Local Skin Temperature

Effect of rate of change in skin temperature on local sweating rate

1979 ◽  
Vol 47 (2) ◽  
pp. 306-311 ◽  
Author(s):  
J. P. Libert ◽  
V. Candas ◽  
J. J. Vogt
Keyword(s):  
Skin Temperature ◽  
Rate Of Change ◽  
Dew Point ◽  
Mean Skin Temperature ◽  
Sweating Rate ◽  
Local Skin ◽  
Local Skin Temperature ◽  
Positive Rate ◽  
Skin Temperatures ◽  
Rate Threshold

To evaluate the relative contributions of positive and negative variations of mean skin temperature (+/- dTsk/dt) on thermoregulatory responses, male resting nude subjects were exposed to rapid or slow alterations in air and wall temperatures (28--45 degrees C; Pa = 20.0 mbar). Rates of heating-cooling cycles were equal to dTa/dt = +/- 3.40, 1.13, 0.57, 0.38, or 0.19 degrees C/min. Continuous measurements were made of rectal, oral, ear, and mean skin temperatures and of arm sweating (dew-point hygrometer method). During all exposures the local skin temperature was kept constant (Tsl = 39 degrees C). The results showed that peripheral inputs are a major factor in thermoregulatory processes. Cutaneous receptors produce a positive and a negative rate component within the central thermal integrator. A higher rate threshold was observed for the positive rate component than for the negative one.

Relation of local skin temperature and local sweating to cutaneous blood flow

1963 ◽  
Vol 18 (4) ◽  
pp. 781-785 ◽  
Author(s):  
Leo C. Senay ◽  
Leon D. Prokop ◽  
Leslie Cronau ◽  
Alrick B. Hertzman
Keyword(s):  
Blood Flow ◽  
Skin Temperature ◽  
Sweat Gland ◽  
Cutaneous Blood Flow ◽  
Local Skin ◽  
Cutaneous Vasodilatation ◽  
Local Skin Temperature ◽  
Relationship Of ◽  
The Relationship ◽  
Cutaneous Blood

The relationship of local skin temperature and the onset of sweating to the local cutaneous blood flow was studied in the forearm and calf. The purpose of the investigation was to appraise the possible relation of sweat gland activity to the cutaneous vasodilatation which has been attributed to bradykinin or to intracranial temperatures. The onset of sweating was not marked by any apparently related increases in the rate of cutaneous blood flow. On the contrary, the onset of sweating was followed often by a stabilization or even a decrease in the level of cutaneous blood flow. The relations of the latter to the local skin temperature were complex, particularly in the forearm. There appeared to be additional unidentified influences, possibly vasomotor, operating on the skin vessels during transitional phases in the relation of skin temperature to blood flow. Submitted on October 15, 1962

The effect of environmental temperature on the growth of vertebrae in the tail of the mouse

Development ◽  
1970 ◽  
Vol 24 (2) ◽  
pp. 405-410
Author(s):  
Janet F. Noel ◽  
E. A. Wright
Keyword(s):  
Skin Temperature ◽  
Environmental Temperature ◽  
Tissue Temperature ◽  
Local Skin ◽  
Temperature Growth ◽  
Peripheral Organs ◽  
Hot Environment ◽  
Caudal Vertebrae ◽  
Local Skin Temperature ◽  
C3h Mice

C3H mice were bred at 30°C and 22°C. At 28 days of age the lengths of the sacral and caudal vertebrae were measured from radiographs and related to the local skin temperature. Growth of the sacral and proximal caudal vertebrae was slightly retarded in the hot environment, but the distal caudal vertebrae showed increased growth which could be quantitatively related to an increase in skin temperature. This suggests that in hot climates the increased growth of peripheral organs of some mammals is due to local increases in tissue temperature.

Influences of overall thermal balance on local inputs for drive of evaporation in men

1987 ◽  
Vol 62 (3) ◽  
pp. 926-931 ◽  
Author(s):  
M. Heising ◽  
J. Werner
Keyword(s):  
Thermal Load ◽  
Sweat Rate ◽  
Thermal Balance ◽  
Whole Body ◽  
Thermal Loads ◽  
Climatic Chamber ◽  
Local Skin ◽  
Local Skin Temperature ◽  
Local Mean ◽  
Regulatory Models

Three kinds of experiments were carried out in a climatic chamber: experiments with warm load on the whole body at 36 degrees C (4 subjects); experiments at 36 degrees C with reduction of thermal load (28 degrees C) on the left leg (right leg at 36 degrees C) (8 subjects); and experiments at 36 degrees C with antisymmetric thermal load on the legs of 44 degrees C (right leg) and 28 degrees C (left leg), which resulted in additional thermal loads of +/- 30 W/leg (8 subjects). The additional thermal loads, which were applied via two climatic boxes, produced measurable effects on sweat rate when applied to one leg only. In comparison to the experiment 1, experiment 2 brought about a significant reduction of local evaporation on the left leg. With antisymmetric thermal loads on both legs (experiment 3), which did not influence the overall thermal balance, there was no significant influence on local evaporation, although significant changes of local temperatures were measured. It is suggested that the well-known regulatory models, declaring local, mean skin, and core temperatures as local evaporation drive should be supplemented with an important additional feature: local control of evaporation by local skin temperature may be blocked by an overall thermal balance.

scholarly journals Effect of local skin blood flow during light and medium activities on local skin temperature predictions

2019 ◽  
Vol 84 ◽  
pp. 439-450
Author(s):  
Stephanie Veselá ◽  
Boris R.M. Kingma ◽  
Arjan J.H. Frijns ◽  
Wouter D. van Marken Lichtenbelt
Keyword(s):  
Blood Flow ◽  
Skin Temperature ◽  
Skin Blood Flow ◽  
Local Skin ◽  
Local Skin Temperature

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.

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