Bestimmung der optischen Eigenschaften trüber Medien mittels nichtinvasiver Remissionsmessungen
Auch gedruckt in der BibliothekW: W-H 12.827
FakultätFakultät für Naturwissenschaften
Ressourcen- / MedientypDissertation, Text
Datum der Freischaltung2012-01-19
In this thesis two techniques for determination of the absorption- and reduced scattering coefficients of turbid media were introduced. The fundamentals of the spatially resolved reflectance method, measured with a CCD-Camera, were investigated and optimized. Further a new method, which measures the total reflectance of a sample, was developed and verified. Using both methods the optical properties of several biological samples could be determined with high spectral resolution. The compliance of both methods ensures the determination quality of the optical properties. For data analysis the light propagation in turbid media was described theoretically using the radiative transfer theory and the diffusion theory. The inverse problem for the determination of the optical properties was solved using a nonlinear least squares algorithm. The systematic errors in the determination of the optical properties caused by using the different theories were investigated. The method was validated using liquid phantoms and the measurement range was specified. The performance of both methods could be shown by determination of the optical properties of different biological samples. The absorption- and reduced scattering coefficients of these samples were determined and, thus, the ingredients of the media could be identified. This work enables the determination of the optical properties of a variety of turbid media which can be used for a lot of applications in the field of process control or medical diagnostics and therapy.
Monte Carlo method