A standard method for repeated recording of skin blood flow using laser Doppler flowmetry

We investigated the simple method of non-invasive Laser Doppler Flowmetry (LDF), and its use as a reproducible standard method for measuring skin blood flow. Microcirculatory blood flow shows both considerable temporal as well as regional variation. The study of reactive changes in skin blood flow, e.g. in irritancy tests, requires repeated measurements. The normal variation of skin blood flow was studied on the forearms of healthy volunteers. Males showed higher values than females. Differences between left and right arms, and recordings in the morning and the afternoon were not significant. Differences between lateral and medial aspects were borderline significant; and significant differences were measured between proximal and distal test sites. To improve the reproducibility of the measurements, a probeholder was designed with a considerably larger test area than that of the original probeholder. Fixation at both ends of the probeholder allows for repeated measurements without affecting skin blood flow. Recommendations are given for repeated testing by LDF.