Hannover 2016 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 59: Poster: Symposium Biomedical Optics (SYBO)
Q 59.1: Poster
Donnerstag, 3. März 2016, 16:30–19:00, Empore Lichthof
Determination of absorption and effective scattering in three-layered biological tissue using the diffusion and P3 approximation — •Simeon Müller, Dominik Reitzle, André Liemert, and Alwin Kienle — Institut für Lasertechnologien in der Medizin und Meßtechnik, Helmholtzstr. 12, 89081 Ulm, Germany
Clinically relevant parameters can be deduced from the scattering and absorption properties of tissue. The radiative transfer equation (RTE) describes light propagation in biological tissue. Solutions are obtained applying different approximations. The most widely used one is the diffusion approximation. It has been solved for infinite, half space and layered geometries but has limitations for short times and small source-detector separations. The spherical harmonic (Pn) approximation approaches the exact solution to the RTE for high orders n. It has recently been solved by our group for the above mentioned geometries.
One way to determine the optical properties of scattering media are time domain measurements. A short pulsed laser beam is targeted on the medium and the time resolved reflectance signal from the surface is measured at a certain distance. Determination of the optical properties is then accomplished by fitting the mentioned models to the measured signal.
With simulated time domain measurements, the determination of the optical properties in three-layered media is investigated, comparing the different approximations. It is shown that already P3 offers a significant improvement to the diffusion theory for optical properties in the typical range of biological tissue.