Natural time analysis
[3] Natural time analysis has been primarily applied to earthquake prediction[1][2] / nowcasting[4][5][6][7][8][9][10][11][12][13] and secondarily to sudden cardiac death[14] / heart failure[15][16] and financial markets.
A related term, pk, is the ratio Qk / Qtotal, which describes the fractional energy released.
Living systems for example are considered to operate far from equilibrium as there is flow of energy crossing their boundaries, in contrast to deceased organisms where inner driving forces are absent.
When κ1 approaches the value κ1 = 0.070 for the candidate region, a critical seismic event is considered imminent, i.e. it will occur in a few days to one week or so.
[4] Nowcasting calculations produce the "earthquake potential score", an estimation of the current level of seismic progress.
(b) the same ECG plotted in (a) but read in natural time analysis
(c) ECG at conventional time upon time reversal
(d) ECG upon time reversal in natural time analysis
The length between RR distances in conventional time is approximately considered as the energy of each pulse (event) in natural time analysis.