Fig. 4.
Experimental studies on the near surface layers of the skin, and on a sample of porcine skin with different, known levels of hydration. (A) Optical image of a stripping disk (D-Squame; CuDerm) on the forearm, as a simple and painless means to uniformly remove a fixed area of SC from the skin. (B) Measurements of ΦBLE (black) and ΦCML,1 (blue), and SC hydration levels (ΦCML,3; red) measured using a commercial device (MoistureMeterSC; Delfin Technologies) as a function of the number of cycles of adhesive disk stripping. (C) Measurements of ∆T12 at short (t = 1 s; black) and long (t = 10 s; red) heating times as a function of the number of cycles of stripping. The vertical bar denotes the spread associated with measurements repeated three times. (D) Optical image of the device mounted on a sample of porcine skin, next to a commercial device (MoistureMeterSC; Delfin Technologies) for measuring SC hydration levels. (E) Measured Φ for a sample of porcine skin with different, known levels of hydration controlled by placing the sample in a food dehydrator (33 °C). (F) Measurements of ∆T12 (square) and linear fits (solid line) at short (t = 1 s) and long (t = 10 s) heating times for a sample of porcine skin as a function of water loss in grams. The changes in ∆T12 exhibit positive correlation with water loss: ∆T12 (10 s) = 6.9 + 0.3 × water loss (R2 = 0.97), and ∆T12 (1 s) = 5.6 + 0.1 × water loss (R2 = 0.85).