Development of a wrist-band type device for low-energy consumption and personalized thermal comfort

Several researches have been investigation the effect of direct human body cooling and warming. Recently, a Japanese research team developed a portable system using Peltier elements that can both cool and warm neck. It is expected to become widespread since it enables to maintain thermal comfort while being low-energy consumption. Though cooling was demonstrated to affect positively both physiological and psychological state in summer heat environment, in cold climate it could be confirmed for only neck warming but not feet and hands. We have proposed and developed the PICO-Band (Personal intelligent comfort control Band) a Peltier element based wearable device that directly warms human body, and studied how wrist warming in cold climate affects physiology. We have measured temperature at index finger, palm and back of the hand, and heat transfer from PICO-Band heating part toward the wrist, in both normal and heating conditions. In heating condition index finger temperature decrease were observed for two among five subjects, who claimed having poor blood circulation. Concerning heat transfer, though heating during 10 minutes, we could observe for all subjects a decrease under 400 W/m2 after two minutes, which corresponded with heating sensation decrease timing.