Quantitative method for evaluating nonstandard tissue absorption characteristics using synergetic near-infrared laser thermography and analytical modeling tools

Abstract The field of laser therapeutic and diagnostic devices has a growing need for innovative experimental and analytical tools to support development of standardized methods for evaluating laser safety and performance. Current laser exposure limits in recognized standards apply only to ocular and skin tissues. These limits do not address safe exposure limits for internal tissues beyond eye and skin, referred to here as nonstandard tissues. Furthermore, the lack of comprehensive databases on laser parameters and tissue optical characteristics complicates the development of quantitative methods for assessing photothermal laser-tissue interactions in nonstandard tissues. To address these gaps, we present a novel proof-of-concept quantitative method for evaluating the absorption characteristics of nonstandard mucosal tissue. The proposed synergetic method integrates laser thermography with computational modeling. Using a near-infrared (NIR) thermography system, we evaluated surface temperatures in ex vivo porcine tongue mucosal tissues at a therapeutic wavelength of 980 nm and powers ranging from 250 mW to 1 W. The absorption coefficients obtained using the synergetic method (72.75 m − 1 ) closely matched those from the conventional spectrophotometric method (71.57 m − 1 ), with a low percentage difference of 1.6%. The results indicate method’s potential to provide accurate and independent evaluation of the absorption characteristics of nonstandard tissues.