1989 Fiscal Year Final Research Report Summary
THERMOREGULATORY RESPONSES OF MAN TO RADIANT HEATING WITH VARIOUS MODES AND INTENSITIES
Project/Area Number |
63480117
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
環境生理学(含体力医学・栄養生理学)
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Research Institution | AICHI MEDICAL UNIVERSITY |
Principal Investigator |
OGAWA Tokuo AICHI MEDICAL UNIVERSITY, DEPT. OF PHYSIOL., PROFESSOR, 医学部, 教授 (50065520)
|
Co-Investigator(Kenkyū-buntansha) |
SUGENOYA Junichi AICHI MEDICAL UNIVERSITY, DEPT. OF PHYSIOL., ASSOCIATE PROFESSOR, 医学部, 助教授 (50109352)
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Project Period (FY) |
1988 – 1989
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Keywords | radiant heating / infrared radiation / wavelength / body temperature / sweating / cutaneous blood flow / skin temperature / thermoregulation |
Research Abstract |
The ventral and/or dorsal aspects (or the left half of the latter) of the sitting nude subject were irradiated continuously (10-60 min), or repeatedly with a period of 4 min (2 min on, 2 min off) by one of 3 kinds of infrared heaters: 'near-infrared'(NIR) with peak wavelength at 1.3 um, 'intermediate-infrared' (MIR) with peak at 3.5 um and 'far-infrared' (FIR) with wavelength ranging 2.8-25 um. at a given intensity (effective radiant temperature of 9.0 or 12.5゚C). Core (tympanic and esophageal) and skin temperatures, finger-tip blood flow, local sweat rates on irradiated and non-irradiated areas, and whole body sweat rate were recorded continuously. An initial fall in core temperature was hardly noted with continuous irradiation to a wide body surface area. Finger-tip blood flow as well as sweat rate increased rapidly and the latter leveled off soon. The rate and degree of rise in core temperature were lower with NIR than the others. Finger blood flow and local sweat rate at the irradi
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ated and non-irradiated areas responded well to periodic irradiations. Sweating response to MIR was predominantly strong on non-irradiated areas. Effects of more restricted ranges of wavelength were also compared by the use of filters, and the range of 3.6-8 um induced a marked sweat response on the irradiated area, whereas the sweat response on remote area were predominantly strong with the range of 2.7-3.5 um. Changes in core temperature (Tty and Tes) in correspondence with periodic heating were minimum, regardless of direct irradiation of the head, whereas shading of the head from the irradiation reduced the rise in core temperature and sweating response during continuous irradiation, and a warmer air temperature was preferred by the subject. In conclusion, infrared radiation of longer wavelengths, especially around 3 um, which is absorbed in a superficial layer of the skin, stimulates strongly cutaneous thermoreceptors and induces effectively heat-dissipating responses, as compared with NIR. Less
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