TISSUE OPTICAL PROPERTY MEASUREMENTS - OVERESTIMATION OF ABSORPTION-COEFFICIENT WITH SPECTROPHOTOMETRIC TECHNIQUES

This study examines the validity of optical property measurements by c omparing surface temperatures rises predicted by a well-tested mathema tical model with temperatures measured experimentally during laser irr adiation. Analysis is based on the early temperature response that is proportional to the absorption coefficient. The results of the investi gation suggest that values for tissue absorption coefficient can be gr eatly overestimated when current spectrophotometric techniques are use d. This seems especially true when a broad light beam and a low port-t o-beam-size ratio are used for transmission and reflection measurement s with an integrating sphere. (C) 1994 Wiley-Liss, Inc.