IV. SINGLE CHANNEL ANALYSIS

Bicoherency spectra during ventricular fibrillation

fig. 4.19: detail of fig. 3.3 shows place of epicardial electrodes and channel nr in experiment 24056
	electrode in fig. 3.2 analysis of experiment in tabular form

Peaks in a bicoherency spectrum indicate significant coherency between the frequency on one horizontal axis, the frequency on the other horizontal axis and their sum; see appendix D. The horizontal axes in the figures below represent the above mentioned frequencies f1 and f2. The points in this f1,f2 plane represent the f1+f2 frequencies. Due to the method of Fourier transform the spectra are estimated in bands of 0.5 Hz, so a difference of 0.5 Hz between f1 and f2 means nothing more than that the real fibrillation frequency lies in between.
The frequencies mentioned below are drawn from the printed spectra, not from the figures!

fig. 4.17: autobicoherency spectrum of channel 4 (fig. 4.19)
figure						references
						auto power spectrum in fig. 4.25
description	Hertz
primary axis	11.5	11.5	11.5	12.0	23.5
secundary axis	12.0	17.5	23.5	23.5	23.5
sum frequency	23.5	29.0	35.0	35.5	47.0
harmonic sequence:	11.75, 23.5, 35.25 & 47.0

fig. 4.18: autobicoherency spectrum of channel 6 (fig. 4.19)
figure								references
								auto power spectrum in fig. 4.12
description	Hertz
primary axis	9.0	7.0	8.5	11.0	11.5	10.0	9.5
secundary axis	9.5	16.5	15.0	12.5	12.0	22.0	23.5
sum frequency	18.5	23.5	23.5	23.5	23.5	32.0	33.0
primary axis	10.5	11.0	11.5	11.5	12.0	13.0	23.5
secundary axis	23.5	23.5	23.5	23.5	23.5	23.5	23.5
sum frequency	34.0	34.5	35.0	35.5	36.0	36.5	47.0
harmonic(?) sequence:	11.75, 23.5, 35.25 & 47.0

fig. 4.28: autobicoherency spectrum of ECG II (fig. 4.19)
figure							references
							auto power spectrum in fig. 4.27
description	Hertz
primary axis	10.0	9.5	11.5	10.5	7.0	23.5
secundary axis	10.5	13.5	12.0	19.5	23.5	23.5
sum frequency	20.5	23.0	23.5	30.0	30.5	47.0
harmonic sequences	10.25 & 20.5 (fig. 4.29)
	11.75, 23.5 & 47 (fig. 4.17 and 4.18)

fig. 4.29: autobicoherency spectrum of channel 5 (fig. 4.19)
figure					references
					auto power spectrum in fig. 4.26
description	Hertz
primary axis	8.0	10.0	10.5	10.5
secundary axis	8.5	10.5	19.0	23.5
sum frequency	16.5	20.5	29.5	34.0
harmonic sequence	10.25 & 20.5

Return to contents of the book.
Return to start page of ventricular fibrillation