Baroreflex_Analysis — Baroreflex analysis using multi channel non stationnary signal analysis method
results = Baroreflex_Analysis(RR,SBP,freq_sampling,frequency_band ,options) results = Baroreflex_Analysis(RR,SBP,freq_sampling,frequency_band ,BPfrequencybounds, BPfilterlength ,options)
a real vector of length N
: The vector
of re-sampled (see ResampleRR) interbeat
intervals of the R waves in the electrocardiogram (ms).
a real vector of length N
: The vector
of systolic blood pressure.
a real positive scalar, the sampling frequency (in Hz) of
the RR
and SBP
signals.
a two column array with Nr
rows,[fmin fmax]
each row specifies a
frequency range (in Hz) to be studied. See the
??? section for details.
a real row vector of length 2
: the band
pass filter frequency bounds (in Hz) or an empty
matrix. In the latter case
BPfrequency_bounds
is set to
[0.9*min(fmin) max(fmax)*1.1]
.
BPfrequency_bounds
is used to perform a
wide range band pass filtering of the given
RR
and SBP
signals.
BPfilterlength
is set to 0 no wide range
band pass filtering is done. See the
??? section for details.
a struct with fields:
<term>sectionlength</term>: an integer, the signal section length to be used for power and cross spectrum computation. The default value is 256.
<term>sectionstep</term>: an integer, the step to be applied for one signal section to the next one. sectionstep must be less or equal to sectionlength. Overlap is sectionlength-sectionstep. The default value is 128.
<term>smoothwindowlength</term>: an integer, the length of the smoothing window (hanning). the default value is 5.
<term>minimalcoherence</term>: a positive number in
]0 1]
. Used to check if RR can be
approximated as a linear filtering of SBP. The
default value is 0.5.
"RRB
typed list with following fields:
M
, the time discretization of
the given RR
and
SBP
signals.
RR
signal.
SBP
: a real row vector, the
given SBP
signal.
M
by Nr
matrix. Each
row contains the smoothed windowed energy of the
RR
signal in the corresponding
frequency range.
M
by Nr
matrix. Each
row contains the smoothed windowed energy of the
SBP
signal in the corresponding
frequency range.
M
, the time discretization of
the comptuded signals.
M
by Nr
matrix. Each
row contains the frequency around which the dispersion of
the RR
signal is minimal in the
corresponding frequency range.
M
by Nr
matrix. Each
column contains the frequency around which the dispersion of
the SBP
signal is minimal in the
corresponding frequency range.
M
by Nr
matrix. Each
column contains the value of the Smoothed Power Spectral
Density (SPSD) at the frequency of minimal dispersion for
the RR
signal in the
corresponding frequency range.
M
by Nr
matrix. Each
column contains the value of the Smoothed Power Spectral
Density (SPSD) at the frequency of minimal dispersion for
the SBP
signal in the
corresponding frequency range.
M
by Nr
matrix. Each
column contains the value of the minimal dispersion for the
RR
signal in the corresponding
frequency range. Dispersion value is zero
when the signal is merely a sinusoide, only one
components, whereas is 1 if the spectra is completely
spread, so there isn't a principal component.
M
by Nr
matrix. Each
column contains the value of the minimal dispersion for the
SBP
signal in the corresponding
frequency range. Dispersion value is zero
when the signal is merely a sinusoide, only one
components, whereas is 1 if the spectra is completely
spread, so there isn't a principal component.
M
by Nr
matrix. Each
column contains the SBP
to
RR
transfer function gain in the
corresponding frequency range.
M
by Nr
matrix. Each
column contains the coherence between SBP
and RR
signals in the corresponding
frequency range.
Signals acquisition and filtering
d=read(cardiovascularpath()+"demos/DATA/tilt_divers",-1,5)';//[RR SBP DBP Vt time] freq_sampling=2; shift=600; RR= d(1,shift:$); SBP=d(2,shift:$);
Analysis
clear options options.sectionlength=64; fbands=[0.04 0.15; //LF 0.2 0.3]; //HF result=Baroreflex_Analysis(RR,SBP,freq_sampling,fbands,options)
Drawing
PlotBaroreflexAnalysis(result,"Tilt")