Photoacoustic determination of the optical absorption coefficient of thermally coagulated blood

摘要

Important to the laser based diagnosis of burn depth is an adequate understanding of the optical properties of thermally coagulated blood. Although the optical properties of photocoagulated blood have been studied in some detail, they are inadequate at completely characterizing the optical properties associated with the thermally coagulated blood of burn injuries. Using a photoacoustic method involving the addition of an absorber to thermally coagulated blood, we obtained data that will be used to derive a spectrum for the optical absorption coefficient, a, of thermally coagulated blood within the wavelength range from 580 to 700 nm. Before implementing this method, the stability of photoacoustic measurements within the diffusion theory realm was tested on two weakly absorbing, highly scattering Intralipid solutions. In addition, the absorber, Chlorazol Black, was tested for resistance to change caused by photobleaching and heating.