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M. Thanaj et al.
Abbreviations
ARA
Attractor reconstruction analysis
BF
Blood flux
CVD
Cardiovascular disease
ETC
Effort to Compress
FFT
Fast Fourier transform
LDF
Laser Doppler flowmetry
LZC
Lempel-Ziv Complexity
MLZC Multiscale Lempel-Ziv complexity
MSE
Multiscale entropy
NO
Nitric oxide
oxyHb Oxyhaemoglobin
PSD
Power spectral density
PU
Arbitrary perfusion units
SampEn Sample Entropy
WT
Wavelet transform
19.1 Introduction
The maintenance of an adequate blood flow through a vascular network sufficient
to meet the metabolic demands of the tissue, is dependent on neural, humoral and
local vaso-mechanisms that determine vascular tone and flow patterns within the
microvasculature. It has been argued that attenuation of these flow patterns may be
a major contributor to disease risk and that quantitative information on the temporal
behaviour and spatial distribution of microvascular perfusion, in vivo, is important
if we are to understand network functionality and flexibility in cardiovascular and
metabolic disease.
To date, time and frequency domain analysis has been extensively used to assess
network functionality and to describe the dynamic characteristics of signals derived
from superficial vascular networks such as that of the skin, obtained using noninvasive laser Doppler fluximetry [24, 54]. Variations in the amplitude and relative
contribution of spontaneous, rhythmic oscillatory fluctuations of local endothelial,
neurogenic, and myogenic origin have become widely associated with a decline in
microvascular function in a wide variety of disease states (see [19]). Impairment of
spatial and temporal regulation of network perfusion by these localised mechanisms
has been shown to give rise to a mismatch between perfusion and demand, particularly
at times of elevated metabolic demand [30]. The consequence of such inadequate
perfusion control is a compromised tissue function, such as that associated with
features of the metabolic syndrome, which eventually leads to the development of
retinopathy, neuropathy, skin ulcers and difficult to heal wounds [25].
M. Thanaj et al.
Abbreviations
ARA
Attractor reconstruction analysis
BF
Blood flux
CVD
Cardiovascular disease
ETC
Effort to Compress
FFT
Fast Fourier transform
LDF
Laser Doppler flowmetry
LZC
Lempel-Ziv Complexity
MLZC Multiscale Lempel-Ziv complexity
MSE
Multiscale entropy
NO
Nitric oxide
oxyHb Oxyhaemoglobin
PSD
Power spectral density
PU
Arbitrary perfusion units
SampEn Sample Entropy
WT
Wavelet transform
19.1 Introduction
The maintenance of an adequate blood flow through a vascular network sufficient
to meet the metabolic demands of the tissue, is dependent on neural, humoral and
local vaso-mechanisms that determine vascular tone and flow patterns within the
microvasculature. It has been argued that attenuation of these flow patterns may be
a major contributor to disease risk and that quantitative information on the temporal
behaviour and spatial distribution of microvascular perfusion, in vivo, is important
if we are to understand network functionality and flexibility in cardiovascular and
metabolic disease.
To date, time and frequency domain analysis has been extensively used to assess
network functionality and to describe the dynamic characteristics of signals derived
from superficial vascular networks such as that of the skin, obtained using noninvasive laser Doppler fluximetry [24, 54]. Variations in the amplitude and relative
contribution of spontaneous, rhythmic oscillatory fluctuations of local endothelial,
neurogenic, and myogenic origin have become widely associated with a decline in
microvascular function in a wide variety of disease states (see [19]). Impairment of
spatial and temporal regulation of network perfusion by these localised mechanisms
has been shown to give rise to a mismatch between perfusion and demand, particularly
at times of elevated metabolic demand [30]. The consequence of such inadequate
perfusion control is a compromised tissue function, such as that associated with
features of the metabolic syndrome, which eventually leads to the development of
retinopathy, neuropathy, skin ulcers and difficult to heal wounds [25].