Photothermal deflection of laser beam as means to characterize thermal properties of biological tissue: numerical study

Non-subjective and early diagnostic technique for liver fibrosis may decrease morbidity in patients and reduce medical costs. Liver fibrosis results in changes in density and thermal properties of tissue. In this work, we evaluate numerically the feasibility of using the optical beam deflection method (OBDM) by means of a thermo-optic material in contact with liver tissue to quantitate changes in thermal conduction. We use the finite-difference method to model the heat transfer in liver and acrylic slab. The response required for thermal characterization for different fibrosis stages is assessed by calculating the deflection angle using ray trace analysis. Numerical study shows the potential of the OBDM for developing an optical-integrated sensor as non-subjective diagnostic technique for liver fibrosis.