Time-resolved Autofluorescence Of Human Nasopharyngeal Tissues In Vitro

The clinical significances of detection for early nasopharyngeal carcinoma, as well as the diagnostic applications of time-resolved autofluorescence spectroscopy, i.e. fluorescence lifetime, for various tumors and other diseases, were presented. Based on the investigation of exiting scientific literatures, the research project for characterization of time-resolved autofluorescence spectra of human normal nasopharyngeal tissues and nasopharyngeal carcinoma was proposed for this thesis.Firstly, the principle and method for the measurement of time-resolved autofluorescence spectroscopy were introduced in detailed. As a result, time correlated single photon counting method was selected as the approach for our measurement.Secondly, the characteristics of the time-resolved autofluorescence spectra of nasopharyngeal carcinoma and normal nasopharyngeal tissues in vitro were investigated, respectively. Subsequently, the average lifetimes of normal nasopharyngeal tissues and nasopharyngeal carcinoma were determined by least squares fitting from the time-resolved autofluorescence spectra. The preliminary results indicate that the nasopharyngeal carcinoma can be discriminated from the normal nasopharyngeal tissues by applied the time-resolved autofluorescence spectroscopy, in particular, the average lifetimes. Furthermore, the discrimination threshold for identifying of normal nasopharyngeal tissues and nasopharyngeal carcinoma was obtained by the statistical analysis.Finally, the effects of blood, processing method for tissue storing, and polarization and coherence of the excited light source on the time-resolved autofluorescence spectra were discussed, respectively, which also plays an important role on the explanations the obtained results.