Estimation of flavin adenine dinucleotide (FAD) concentration in turbid medium from laser-induced autofluorescence spectra
Lim, Fei Sheng
Date of Issue2014
School of Chemical and Biomedical Engineering
Autofluorescence spectroscopy and imaging has been explored extensively for tissue characterization including cancer diagnosis during past years. A lot of physiological information such as fluorophore concentrations, redox ratio, etc., can be extracted from autofluorescence spectra. However, quantitative measurement of these physiological parameters in tissue in vivo is still very challenging due to the fact that the measured fluorescence signal is influenced heavily by the background absorption and scattering. In this project, a correction method is explored to recover intrinsic fluorescence of flavin adenine dinucleotide (FAD) from raw fluorescence spectra that distorted by surrounding medium’s absorption and scattering. Moreover, the concentration of FAD was estimated from the intrinsic fluorescence spectra. Skin tissue phantom experiments were carried out to investigate the accuracy of the established model. Raw fluorescence spectra from tissue phantoms with different optical properties and concentrations of FAD were corrected through the established model. As depicted by the results, computed intrinsic fluorescence of FAD in tissue phantoms are free from distortions by background optical properties. The concentration of FAD of tissue phantom has been estimated accurately by the established normalization model. The average coefficient of determination (R^2) and average root mean square (RMS) error for the estimated concentrations of FAD are 0.9845 and 0.58%, respectively. Our study shows that the established model is a promising method to recover intrinsic fluorescence spectra and estimate concentration of FAD. In future works, a more sophisticated model will be developed to extract the intrinsic fluorescence of multiple endogenous fluorophores from turbid medium.
Final Year Project (FYP)
Nanyang Technological University