Wavelet analysis of oscillations in the peripheral blood circulation measured by laser Doppler technique.
The wavelet transform technique, a time-frequency method with logarithmic frequency resolution, was used to analyze oscillations in human peripheral blood flow measured by laser Doppler flowmetry. The oscillations extended over a wide frequency scale and their periods varied in time. Within the frequency range studied, 0.0095-1.6 Hz, five characteristic oscillations were revealed, arising from both local and central regulatory mechanisms. After the insertion of endothelium-dependent and endothelium-independent vasodilators the spectra of blood flow markedly differed in the frequency interval 0.0095-0.02 Hz. In this way it was demonstrated that endothelial activity is a rhythmic process that contributes to oscillations in blood flow with a characteristic frequency of around 0.01 Hz. The study illustrates the potential of laser Doppler flowmetry combined with dynamical systems analysis for studies of both the micro- and macroscopic mechanisms of blood flow regulation in vivo.
Stefanovska
A
A
Faculty of Electrical Engineering, University of Ljubljana, Slovenia. aneta@osc.fe.uni-lj.si
Bracic
M
M
Kvernmo
H D
HD
D000109:Acetylcholine / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007478:Iontophoresis; D017078:Laser-Doppler Flowmetry / Q000379:methods*; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D009991:Oscillometry / Q000379:methods; D011673:Pulsatile Flow / Q000187:drug effects; D012039:Regional Blood Flow / Q000187:drug effects; D012815:Signal Processing, Computer-Assisted; D012867:Skin / Q000098:blood supply*; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D009599:Nitroprusside; D000109:Acetylcholine