Optical phantom materials for near infrared laser photocoagulation studies

Abstract

Background and Objective Phantoms were developed that simulate tissue with dynamic and static optical properties with which to study the effects of laser irradiation. Study Design/Materials and Methods Albumen, agar, and an absorbing dye (Naphthol Green) were combined to form a phantom with heat sensitive optical properties to mimic tissue response. The optical properties of this phantom were measured by using the added absorber technique. A polyacrylamide phantom with static optical properties was designed with the equivalent values of μa and μ′s by combining appropriate concentrations of Naphthol Green and Intralipid-10%. Results The absorption and reduced scattering coefficient of the phantoms were 0.50 ± 0.04 cm−1 and 2.67 ± 0.07 cm−1 respectively, in the native state at 805 nm. In the coagulated state, the absorption and scattering coefficient were 0.7 ± 0.1 cm−1 and 13.1 ± 0.5 cm−1 respectively. Conclusion Two phantoms with dynamic or static optical properties were developed with properties similar to tissue. They may be used in future studies of opto-thermal effects in tissues. Lasers Surg. Med. 25:159–169, 1999. © 1999 Wiley-Liss, Inc.