Infrared fiber optic spectroscopy: A novel tool for skin diagnosis

Fiber Evanescent Wave Spectroscopy (FEWS) is a very useful method for non-invasive and non-destructive biomedical diagnosis. We have developed a FEWS system that makes use of a Fourier Transform Infrared (FTIR) spectrometer and IR transmitting AgBr_xCl_1-x fibers. The FTIR-FEWS system is compact and easy to use, and it is ideal for the study of the spectroscopy of the skin in the mid-IR. The evanescent wave penetration depth in the mid-IR is comparable with the thickness of the stratum corneum, and therefore the vibrational spectra of lipids, proteins and water can be easily analyzed. We have used FTIR-FEWS for a clinical study of the skin of 60 patients, who had some suspicious skin lesions. Preliminary measurements were carried out both on the lesion and on neighboring healthy areas of the skin, showing some differences in the IR absorption. More data is needed in order to determine the possibility of diagnosis of skin cancer and its type from mid-IR spectral data.