Thermically induced changes in optical properties of heart

Optical properties of ventricular myocardium (dog) were determined at two helium-neon laser wavelengths, 594 nm and 633 nm. The absorption coefficient and reduced scattering coefficient were deduced from integrating sphere measurements of total transmission and total reflectance. The changes caused by variable time exposure to various temperatures (water bath) were documented. The temperature dependence of the degree of coagulation achieved by heating, scored by the final stable optical properties, suggests that a heterogeneous population distribution of tissue structures is involved in coagulation.<>