Figure 5

The figure illustrates the surface and subsurface temporal maximum temperature profiles calculated by the finite element model during laser heating and subsequent cooling (pulse duration listed). The surface temperature profile and six different depths are displayed (100, 200, 300, 400, 500 μm and the depth of the epidermal ridge (ER), which is 130 μm in glabrous skin and 50 μm in hairy skin). It is seen that the delay to reach the maximum temperature after stimulus termination increased with depth, as the heat energy took longer time to diffuse into the skin. Comparing the temperature profile at the ER in hairy and glabrous skin, it is seen that following 5 W stimulations the maximum temperature was almost twice as high in hairy skin as it was in glabrous skin. For the 1 W data the differences were not as pronounced, because the slower heating allows better time for the heat time to diffuse into the skin. A) glabrous skin, 1 W, 0.6 s, 0.6 J/cm² B) hairy skin, 1 W, 0.6 s, 0.6 J/cm² C) glabrous skin, 5 W, 0.12 s, 0.6 J/cm² D) hairy skin, 5 W, 0.12 s, 0.6 J/cm².