This is a novel method—existing patents I've seen on melanoma scanners generally fall into the category of 3D imaging and computer vision to automate what a clinician does to various degrees.
So is it basically that the specific heat capacity of the material in the top layers of the skin is altered when there's melanoma present, so when it's cooled one can observe that this part warms more slowly (?) than the surrounding tissue (because of density?).
It seems likely to me that there would be a difference in reflectivity/transmittivity too that could be detected by using a strong light source that could penetrate the exterior dermal layers. Presumably active scanning like MRI (or microwave heating - probably too risky) would show the differences well too?
Would be interesting to read about the range of methods that have been tested (conductivity using surface contact probes would seem another obvious method?).
The benefit, as it appears, of the current method is probably simplicity but it doesn't appear to scale to scanning the full surface readily.
