Spectral IR tissue diagnostics with photothermal detection

Photothermal (PT) and Photoacoustic (PA) Step-Scan FT-IR measurements are successful tools for thickness determination of layered samples. Aiming to separate optically between different layered tissues, we have been able to distinguish skin, liver and muscle tissues by means of PT and PA measurement techniques. Performing Step-Scan FT-IR measurements, the PT and PA phase and amplitude signals follow the tissue's absorption peaks which corresponds to the transmission spectra. These results are supported and confirmed by a simulation using the Finite- Difference-Method whereat the basic spectral data from transmission measurements and some assumed thermal properties of investigated tissues have been inserted.