“…In addition to the temporal, spectral, and non-linear parameters already discussed, the EHG electrical activity, as measured on the abdominal wall, also allows propagation analysis of EHG signals [ 32 ], propagation analysis of uterine contractions [ 33 ], and evaluation of directionality and synchronization of the EHG signals [ 34 ]. These include: estimation of conduction or propagation velocity amplitudes [ 10 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ], estimation of conduction velocity directions [ 39 , 40 , 41 , 42 , 43 ], estimation of propagation patterns [ 40 , 42 ], estimation of directionality, synchronization, and coupling [ 34 , 44 ], and estimation of spatiotemporal EHG patterns [ 45 ].…”