Study of smartphone suitability for mapping of skin chromophores

Abstract

RGB (red-green-blue) technique for mapping skin chromophores by smartphones is proposed and studied. Three smartphones of different manufacturers were tested on skin phantoms and in vivo on benign skin lesions using a specially designed light source for illumination. Hemoglobin and melanin indices obtained by these smartphones showed differences in both tests. In vitro tests showed an increment of hemoglobin and melanin indices with the concentration of chromophores in phantoms. In vivo tests indicated higher hemoglobin index in hemangiomas than in nevi and healthy skin, and nevi showed higher melanin index compared to the healthy skin. Smartphones that allow switching off the automatic camera settings provided useful data, while those with “embedded” automatic settings appear to be useless for distant skin chromophore mapping.

Multispectral, Fluorescent and Photoplethysmographic Imaging for Remote Skin Assessment

“…Specially developed software transmits the obtained spectral images via mobile network to a remote server that converts them into distribution maps of the three main skin chromophores (melanin, oxy- and deoxy-hemoglobin) and then transmits the maps back for displaying on the smartphone touchscreen. More details on the RGB-LED smartphone add-on prototype and its tests are provided in [17,18]. …”

“…Design scheme of smartphone RGB illuminator ( a ) and normalized emission spectra of the used color LEDs ( b ) [18]. …”

“…Spectral images of skin malformations taken by different prototypes: ( a ) nevus taken by smartphone—RGB LED prototype at white, red, green and blue illumination [18]; ( b ) nevus taken by SkImager at white, red, green, blue and NIR illumination [49]; ( c ) papilloma taken by modified video-microscope at blue, green, red and NIR illumination [23]; ( d ) melanoma taken by modified video-microscope at blue, green, red and NIR illumination [23]. …”

Multispectral, Fluorescent and Photoplethysmographic Imaging for Remote Skin Assessment

“…Five AA 2800 mAh rechargeable battery blocks provide the system power supply. Design scheme of smartphone RGB illuminator (a) and normalized emission spectra of the used color LEDs (b) [18]. Fig.2,a provides more design details of the prototype.…”

“…After processing 16. Spectral images of skin malformations taken by different prototypes: a -nevus taken by smartphone -RGB LED prototype at white, red, green and blue illumination [18], b -nevus taken by SkImager at white, red, green, blue and NIR illumination [49], c -papilloma taken by modified video-microscope at blue, green, red and NIR illumination [23], d -melanoma taken by modified video-microscope at blue, green, red and NIR illumination [23]. …”