Time–amplitude analysis of skin blood flow oscillations during the post-occlusive reactive hyperemia in human

Age‐related changes of skin blood flow during postocclusive reactive hyperemia in human

“…A complex-valued Morle wavelet was used as the analyzing function; this wavelet is widely used to study LDF signals (21,27,29,31,44,45,52,53). The use of adaptive wavelet filtering allows one to study the low-frequency components of transient (fast) transitional processes on the starting interval, right after the cuff release (21,45). The oscillatory components of the postocclusive LDF-signal fragments were discriminated as described earlier (21,45).…”

“…The number of articles considering the mechanisms of skin aging is growing (7,(9)(10)(11), and the age-related changes of skin morphology and structure are now well-studied (11,12). There is also a num-ber of works which make use of the laser Doppler flowmetry (LDF) technique and study the age-related changes of skin perfusion with bloodboth at rest and under certain stimuli (4,9,(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). To assess adaptive reserves of the microvascular bed and to judge the state of the mechanisms that regulate blood flow in tissues, researchers apply various functional tests, with the occlusion test being one of those used most frequently (13,17,18,20,21,(23)(24)(25)(26).…”

Anesthesia effects on the low frequency blood flow oscillations in mouse skin

“…Skin blood flow oscillations were well studied with laser Doppler (LDF) flowmetry technique and wavelet transform in human and rat skin. [1][2][3][4][5] Now it is widely accepted that frequency of peripheral blood flow oscillations are divided into several intervals 2,3 : 0.005-0.021 Hz-endothelial activity (I); 0.021-0.056 Hz-neurogenic activity (II); 0.056-0.145 Hz-myogenic activity (III); 0.145-0.6 Hz-respiratory rhythm (IV); 0.6-2 Hz-cardiac rhythm (V). Some researchers divided the oscillations in the endothelial interval on NO-depended and NOindependent rhythms.…”

Quantifying low-frequency fluctuations in the laser Doppler flow signal from human skin

“…As can be seen, deviations higher than 100% were observed. Thus the time domain analysis revels very slow and large amplitude changes, suggesting that longer timeaverage intervals than those normally used should be considered ( [3] use one minute and [4] use five minutes). Table 1).…”

“…However, the quantity (P) is the mean power of the flow fluctuation in a selected frequency band and this method does not allow the study of the temporal response of microvascular flow to a stimulus. Recently the wavelet analysis in short time-intervals [3] and adaptive wavelet transform [4] were proposed for analyzing the flow oscillations in the time domain. The analysis of temporal fluctuations of flow in spectral bands, preserving the phase and amplitude of the signal in each spectral band, is beyond of the scope of these works.…”