643563.fig.008a
(a)
643563.fig.008b
(b)
643563.fig.008c
(c)
643563.fig.008d
(d)
643563.fig.008e
(e)
643563.fig.008f
(f)
Figure 8: HRV spectra obtained by means of different methods: (a)equidistantly repositioned HR samples with frequency axis scaled according to the mean heart period; unevenly sampled heart rate sequence resampled to evenly spaced signal- (b) cubic-spline interpolation, (c) nearest neighbour interpolation, (d) Berger method; spectra computed without resampling-, (e) Lomb-Scargle periodogram, (f) spectrum of counts.