286
A. V. Tankanag et al.
Fig. 18.4 Box-Whisker plots for the phase coherence values of skin blood flow oscillations of
left and right fingers. The asterisk symbol (*) indicates statistically significant differences between
spontaneous and controlled breathing (p < 0.05)
Table 18.1 Median values of
phase coherence function
between skin blood flow
oscillations of left and right
fingers
Frequency (Hz)
Breathing regimes
Spontaneous
Controlled
0.05
0.41
0.84*
0.07
0.46
0.75*
0.1
0.49
0.92*
0.16
0.31
0.89*
0.25
0.28
0.83*
* statistically significant differences between spontaneous and
controlled breathing (p < 0.05)
presented in the Fig. 18.4 and Table 18.1. There is significant increase in phase
coherence of SBF left –SBF right pair for all breathing regimes. The maximal increase
was observed for controlled breathing at 0.25 Hz which is close to the spontaneous
breathing rate. At this frequency, the median of phase coherence value was approximately three times higher under controlled breathing as compared to spontaneous
one (Table 18.1).
18.4 Discussion
We obtained the significant increase of phase coherence of skin blood flow
oscillations of left and right forefingers for all regimes of controlled breathing.
The respiratory-related variations in peripheral hemodynamics can originate from
changes in the arterial blood pressure induced by thoracic pressure changes and
passively transmitted from large to small arteries [5] or from peripheral sympathetic