Comparison between Laser Doppler Flowmetry Signals Recorded in Glabrous and Non Glabrous Skin - Time and Frequency Analyses

Skin microvascular properties vary with anatomical zones. Thus, glabrous skin found in fingers, toes, nail beds, hand palms and feet soles has a high density of arteriovenous anastomoses (AVAs). In contrast, skin found in sites such as ventral face of the forearms do not possess AVAs and therefore microvascular blood flow in this non glabrous skin is different. We herein propose to analyse laser Doppler flowmetry (LDF) signals that reflect skin microvascular perfusion, in two different sites of healthy subjects: hand (glabrous skin) and ventral face of the forearm (non glabrous skin). The signal analysis is performed both in the time and in the frequency domains. Our results show that the mean amplitude of LDF signals recorded in the hand is generally higher than in the forearm. Moreover, the signal fluctuations observed in the hand are much higher than the ones observed in the forearm. Our work also shows that the power spectrum of LDF signals recorded in hand and forearm can be different. They both may possess characteristics of fractal processes but these characteristics may be different for the two anatomical sites.