Thermal properties calculated from measured water content as a function of depth in porcine skin

In order to develop a realistic tissue water boiling routine for a mathematical model of burn development, it was necessary to know the water content and the thermal properties of skin as a function of depth. Split thickness skin samples were obtained from several pigs using an air-powered dermatome. Alternate segments of these skin slices were processed for skin water content determination and for histopathologic measurements of skin thickness. Tissue samples were weighed, dried and subsequently weighed again using standardized methods to determine tissue water content. In some instances the volume of tissue was also determined to allow the calculation of tissue density. Given a table of measured values of water content as a function of skin thickness, a least-squares cubic polynomial was fitted to the data and water content as a function of depth was computed from the following formula: w(T-d) = T/d x (WT-WT-d)+WT-d where T is the total thickness of a skin slice, WT is the fraction of water computed from the cubic equation, d is the thickness of the skin slice at a depth T-d, and WT-d is the fraction of water above the thin slice. Stratum corneum hydration was calculated from measured ambient relative humidity based on a relationship previously described by Rushmer et al. (1966). Skin thermal properties as a function of depth were calculated using the formulation of Cooper and Trezek (1971).(ABSTRACT TRUNCATED AT 250 WORDS)