BIOENGINEERING AND THE SKIN - FROM STANDARD ERROR TO STANDARD OPERATING PROCEDURE

Bioengineering techniques for examination of the skin, measuring princ iples and sources of error relative to technique, study design, measur ing conditions and variability related to test subjects and preconditi oning are reviewed. Principles of validation and standard operating pr ocedures (SOP) are discussed, including guidelines for measurement of transepidermal water loss (TEWL) and laser Doppler cutaneous blood flo w. Today typical errors are not related to a measuring device but to t he way it is used.