Optical radar detection of precancerous bronchial tissue

Previous measurement of laser-induced fluorescence in bronchus tissue is si mulated using an electromagnetic (EM) scattering model. The EM parameters d erived indicate that the changes in the thickness of the epithelium associa ted with carcinoma in situ can be detected using an optical radar process, providing an early detection of cancer. Further simulation using the EM mod el indicates various practical methods of measuring the thickness, includin g frequency modulated continuous wave optical radar, multi-laser continuous wave radar and low coherence interferometry. Initial optical experiments a nd calculations have demonstrated which of the methods is likely to lead to the development of an endoscopic instrument. The availability of suitable optical components is a major consideration. Some early interferometry resu lts indicate that a resolution of at least 40 mu m and a signal to noise of up to 45 dB can be readily reached for histological imaging.