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Cardio Vascular toolbox >> Cardio Vascular toolbox > CDM_SPWVD_Analysis

CDM_SPWVD_Analysis

Performs the analysis of a narrow band component of the RR signal using Smoothed Pseudo Wigner-Ville time-frequency distribution and complex demodulation methods.

Calling Sequence

result =
CDM_SPWVD_Analysis(RR,Vt,freq_sampling,frequency_bounds,filterlength
[,options])

Parameters

RR
a real vector of length N: The vector of interbeat intervals of the R waves in the electrocardiogram (ms).
Vt
It can be:
  • either a real scalar: that gives the frequency reference (in Hz)
  • or a real vector of length N: The tidal volume respiratory signal. its slowly varying frequency gives the frequency reference.
See the Caution section for details.
freq_sampling
a real positive scalar, the sampling frequency (in Hz) of the signals.
frequency_bounds
a real row vector of length 2: the frequency range of interest (in Hz).See the Caution section for details.
filterlength
a real scalar with integer value: the order of the FIR Hamming band_pass filter. Caution section for details.
options
A struct with possible fields:
  • lowpass: an odd length vector of real numbers. The coefficients of a fir lowpass filter used to smooth the resulting signals. The default value is computed by wfir("lp",195,[0.01 0],"hm",[0,0]).
  • timewindowlength: a real scalar with positive integer odd value. The time smoothing window length used in the smoothed pseudo Wigner-Ville distribution. The default value is 77.
  • frequencywindowlength: a real scalar with positive integer odd value. The frequency smoothing window length used in the smoothed pseudo Wigner-Ville distribution. The default value is 75.
  • frequencybins a real scalar with positive integer power of 2 value. The number of frequency bins used in the smoothed pseudo Wigner-Ville distribution. The default value is 128.
results
a typed list with type "RRA" and with the following fields:
  • time: a real row vector of length N, the time discretization associated with the following signals.
  • RR: a real row vector of length N, the shifted RR signal
  • Vt: a real row vector of length N, the shifted Vt signal or the empty matrix.
  • RRfiltered: a real row vector of length N, the shifted band-pass filtered RR signal.
  • IFreq_CDM: a real row vector of length N, the instaneous frequency of the RR signal (in Hz) estimated by complex demodulation method.
  • IFreq_SPWVD: a real row vector of length N, the instaneous frequency of the RR signal (in Hz) estimated by smoothed pseudo Wigner-Ville method.
  • IAmp_CDM: a real row vector of length N, the instaneous amplitude of the RR signal estimated by complex demodulation method.
  • IAmp_SPWVD: a real row vector of length N, the instaneous amplitude of the RR signal estimated by smoothed pseudo Wigner-Ville method.
  • IPhase: a real row vector of length N, the evolution of the instaneous phase shift between the RR and Vt signals.
  • IPow: a real row vector of length N, the instaneous power of the RR signal.
  • IDisp: a real row vector of length N, the instaneous dispersion of the RR signal.

Description

CDM_SPWVD_Analysis Performs the analysis of a narrow band component of the RR signal using both Complex demodulation and Smoothed Pseudo Wigner-Ville time-frequency distribution methods. It estimates the instaneous frequency, the instanenous amplitude, the instaneous power and the instaneous dispersion of the RR signal. It allows a simple comparison of both methods.

Caution

Examples

See Also

Authors

Bibliography

Short-term control of the cardiovascular system: modelling and signal analysis Alessandro Monti , Claire Médigue , Michel Sorine. Rapport de recherche n° 4427 April 12, 2002

"Instantaneous parameter estimation in cardiovascular time series by harmonic and time-frequency analysis", Alessandro Monti , Claire Médigue , Mangin Laurence,IEEE Trans Biomed Eng. 2002 Dec;49(12 Pt 2):1547-56.

"Instantaneous envelope and phase extraction from real signals: Theory, implementation, and an application to EEG analysis". Periklis Y. Ktonasa and Nicola Papp

Used Functions

  • TimeMoments
  • ComplexDemodulation
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