Optimal lighting of RGB LEDs for oral cavity detection.

In this paper the optimal lighting for oral cavity detection is proposed. The illuminants consist of several LEDs with different intensity ratios and peak wavelengths, which can enhance the color difference between normal and abnormal regions in the oral cavity. An algorithm combined with multi-spectral imaging (MSI) and color reproduction technique is applied to find the best enhancement of this difference. The colored LEDs of the optimal lighting, the Color Rendering Index (CRI) of the illuminants, and comparison with traditional illuminants are discussed. The calculations show that color enhancement ability in the oral cavity is not entirely a function of the higher CRI of some illuminants, as the narrowband illuminants (LEDs) produce an image with greater contrast than the broadband spectra and higher CRI of traditional illuminants in the reddish oral environment. Accordingly, an illuminant with specific intensity ratio of red, green, and blue LEDs is proposed, which has optimal color enhancement for oral cavity detection. Compared with the fluorescent lighting commonly in the use now, the color difference between normal and inflamed tissues can be improved from 21.5732 to 30.5532, a 42% increase, thus making medical diagnosis more efficient, so helping patients receive early treatment.