Characterization and Optical Early Diagnosis by Diffuse Reflectance Spectroscopy

Diffuse reflectance spectroscopy (DRS) is a technique that illuminates the surface of the tissue and analyzes the spectrum of backscattered light, in which the signature of various biochemical species can be identified. This promising technique is established in this article for the non-invasive and in vivo characterization of the optical properties of tissues for diagnostic applications. We have introduced a new compact and inexpensive architecture for DRS based on the use of a multispectral image sensor and LEDs to obtain a diffuse reflectance signal in contact with the skin. For the proof of concept, a prototype device, involving a spectrometer coupled to an optical fiber, a microcontroller, a set of 8 LEDs and a computer, was developed, manufactured and set up. Diffuse reflectance profiles were acquired at 438.2 nm, 544.5 nm and 613.7 nm. Indeed, the spectrum of Mycobacterium ulcerans was established by this method at 256 nm and 365.2 nm. The results obtained confirm the potential of our approach for the quantitative characterization of the optical properties of tissues.