Figure 4From: Estimating the distribution of dynamic invariants: illustrated with an application to human photo-plethysmographic time seriesHuman pulse waveform recorded withphoto-plethysmography. Four recordings of human pulse waveform (61 Hz) in four different physiological conditions. The four time series correspond to: (a) normal, (b) quasi-stable, (c) unstable, and (d) post-operative (stable).Back to article page