Skin chromophore mapping from multi-spectral laser line images

Skin chromophore maps can be used for assessment of various skin malformations and early cancer diagnostics. Commercially available devices are bulky and expensive. We present two portable proof-of-concept device prototypes for multi-spectral laser line imaging with three (448 nm, 532 nm and 659 nm) and four (450 nm, 523 nm, 638 nm and 850 nm) wavelength laser illumination. Laser modules and special optics that ensure uniform light distribution over the region of interest have been exploited. Skin chromophore maps were calculated using Beer-Lambert law, considering light scattering properties in the skin and including photon path length evaluated from the directly measured photon-time-of-flight signals. Chromophore concentrations in the lesion are compared to the surrounding healthy skin. In vivo measurement results were compared with the results obtained from agar-based multi-layered skin phantoms which mimic vascular and pigmented skin lesions.