Figure 1: Phase response curve from non-invasive observation: scheme of the approach.
From: In vivo cardiac phase response curve elucidates human respiratory heart rate variability
(a,b) The respiratory signal, the electrocardiogram, and the arterial pulse are simultaneously recorded from subjects in resting state. (c,d) From these scalar signals, by virtue of a proper 2D embedding, the protophases θr, θe, and θp are obtained and transformed to the phases φr, φe, and φp, shown in e. (In this schematic representation the difference between θe and φe is not seen). (f) The coupling (interaction) function describing the effect of respiration on heart dynamics is reconstructed in an invariant way. (g) The coupling function is decomposed into the phase response curve PRC and the respiratory forcing.
