Fig. 1.

Schematic representation of the factors involved in the calculation of the normalization factor. The signal s(t) is segmented into active segments s_k(t). For each active segment there are 2^n_u possible MUAP combinations x_k (sets of circles, each set here showing the 4 possible combinations of 2 different MUAPs). A segment-wise annotation X (heavy line) is equivalent to a path through this trellis and corresponds to a specific firing pattern T. The likelihood of the annotation is the product of shape-dependent factors associated with each active segment and firing-time-dependent factors associated with the firing pattern. Computing the normalization factor requires summing the likelihoods of all possible paths.