Wavelet Phase Coherence Analysis of Cardiovascular and Respiratory Oscillations in Human

Wavelet phase coherence between respiration rate, heart rate variability (HRV), skin blood flow and tissue blood volume oscillations were studied in healthy volunteers at rest. High phase coherence between respiration rate and tissue blood volume oscillations and low phase coherence between respiration and skin blood flow ones was obtained. Analogous results were found for phase interactions between HRV and peripheral hemodynamics. High coherence between HRV and tissue blood volume oscillations and low coherence between HRV and skin blood flow ones was found at respiration frequency (~ 0.3 Hz). There were similarities of phase coherence of both analyzed signals (skin blood flow and tissue blood volume) with HRV in low frequency range from 0.0095 to 0.1 Hz. The results obtained can be used for developing new diagnostic approaches for state assessment of peripheral vessels in various pathologies.