Heat transfer behavior and physiological effects of living human skin under local radiative thermal stimulation

In order to develop a moxibustion treatment device that can heat appropriately by radiation while lowering the risk of burning by the moxa, a local radiative heating device for skin was fabricated and the unsteady response of the skin surface and internal temperature during infrared radiative heating were evaluated based on subjective experiments and numerical analysis. Because it was necessary to perform non-contact temperature measurements of the heated surface to control the heat, methods of evaluating and correcting the impact on measurement precision were studied. The study clarified that as skin was heated, the skin surface temperature rose, and the blood flow speed around the heated part increased. A local thermal sensation corresponded to the increase. Absorption of radiation by skin occurred only near the surface, so it was concluded that a useful way to effectively heat skin, was to set a certain temperature as the upper limit of the surface temperature, and lower the heat when this temperature has been reached, wait for the heat to penetrate more deeply, then restart heating.