NONCONTACT IMAGING OF THERMAL-PROPERTIES OF THE SKIN

Non-contact measurement of thermal properties of the skin was performe d by using a thermovision camera and a mechanical system that provides a step change in ambient radiation temperature. A hood maintained at 20 degrees C was initially placed so as to cover the object surface to wards which a thermovision camera was directed. Then the hood was quic kly replaced by another hood maintained at 40 degrees C. Thermograms b efore, immediately after and 20 s after switching the hoods were taken . Then the image of emissivity was computed from thermograms taken bef ore and immediately after hood switching, and the emissivity-corrected thermograms were computed by using the emissivity value obtained at e ach pixel. The images of the square root of the product of thermal con ductivity, density and specific heat were computed from thermograms ta ken immediately after and 20 s after hood switching. While images of t he emissivity obtained and the thermal parameter defined above contain ed significant noise, differences in these quantities between sites co uld be clearly demonstrated.