A Theoretical and Experimental Investigation of the Temperature Response of Pig Skin Exposed to Thermal Radiation

Abstract

This study was undertaken as a part of the problem of predicting the irreversible thermal injury of skin. Of first importance in this problem is the determination of the temperatiire-time-depth history of skin subjected to an arbitrary thermal insult. Although this paper deals with radiant energy heating of skin, it is intended that the results may be applied to other modes of energy input, as well.The theoretical analysis of heat flow in irradiated skin is considered first, and the predicted responses of two models are presented. Methods are developed for the comparison of these theoretical predictions with experimental resultsJ these comparison schemes define the experimental procedures and materials which are next described in detail. Finally, the experimental results are presented, together with an evaluation of the constants of skin, whenever possible» While the experimental results failed to supply all the information necessary to compute the temperature response of skin to any arbitrary energy input, several important conclusions were reached. A most interesting result of the theoretical analysis is that the absorption pattern of radiation in skin may be determined directly by temperature measurements, and the data may be tested rigorously for their validity. Also, it is now possible to plan future experiments which will provide the necessary data which this study failed to supply. Most important is the indication that the desired prediction of thermal injury of skin may be achieved. ill

Analysis of Laser Induced Skin Burns by a Damage Integral Model

“…, depth.4781 eX4t _ I erfc (;a ;4a The temperature change during the exposure period is given by equation (7) and following the termination of radiation exposure by equation (8).…”

“…The numerical values of the thermal constants used in these calculations, U = 11.8 x 10-4 and a = 8.6 x 10-4, were derived experimentally' by Davis (8,9) for porcine skin. A temperature of 36 0 C was assumed for the temperature at time zero in all cases.…”

In Vivo Temperature Measurements*

“…A case in point is the solution for the response of skin heated by penetrating radiant energy. If the model is chosen to reflect the known optical properties of skin, the solutions become extremely complex (10). Numerical values of the appropriate parameters may be chosen from the literature, and numerical solutions obtained, but this procedure does not allow a critical evaluation of these literature values, nor a satisfactory comparison of theory and experiment.…”