Fourier transform infrared evanescent wave (FTIR-FEW) spectroscopy tissue

A new Fourier Transform Infrared Fiberoptic Evanescent Wave (FTIR-FEW) Spectroscopy method has been developed for tissue diagnostics in the middle infrared (MIR) wavelength range (3 to 20 mu m). Specific novel fiberoptical chemical and biological sensors have been studied and used for spectroscopic diagnostic purposes. These nontoxic and nonhygroscopic fiber sensors are characterized by (i) low optical losses (0.05 to 0.2 dB/m at about 10 mu m) and (ii) high flexibility. Our new fiber optical devices can be utilized with standard commercially available Fourier Transform Spectrometers including attenuated total reflection (ATR) techniques. They are in particular ideally suited for noninvasive, fast, direct, sensitive investigations of in vivo and ex vivo medical diagnostics applications. Here we present data on IR spectra of skin tissue in vivo for various cases of melanoma and nevus in the range of 1480-1800 cm(-1). The interpretation of the spectra of healthy and different stages of tumor and cancer skin tissue clearly indicates that this technique can be used for precancer and cancer diagnostics. This technique can be designed for real-time and online computer modeling and analysis of tissue changes.