Measurements of Tissue Optical Properties Using an Integrating Sphere Set Up

Lasers have found many applications, such as photodynamic therapy and laser surgery, in medicine The light distribution within the tissue is determined by the optical properties of the irradiated tissue and thus it is the optical properties of the tissue that determine the biological effect of the radiation. Many of these applications induce heat and it is therefore interesting to see how this heat affects the optical properties. In this study the optical properties of rat liver tissue were determined using an integrating-sphere set up in combination with a Monte Carlo spline interpolation program. Thermotherapy was used to induce heat in the tissue The optical properties for the treated and untreated were compared and the result showed considerate differences in all optical interaction coefficients Thus the effect of heat induced changes in the optical properties of tissue has to be considered for laser dosimetry applications Table of Content