
Single channel signal 73
in ApEn were pointed out in [Richman and Moorman, 2000] and [Costa et al., 2002]
and another measure called sample entropy (SaEn) was introduced in [Richman and
Moorman, 2000].
In the SaEn method the vectors (blocks) ξ(i) of differing dimensions k are cre-
ated by embedding a signal in a way similar to that given in formula (2.128). The
reconstructed vectors are the state space (k-dimensional) representation of the dy-
namics of the system. SaEn is defined as the logarithmic difference between the
probability(density) of occurrence of the vector ξ(i) within the chosen distance r in
k dimensions and the probability of occurrence ...