1. A computer-implemented method for the analysis of a biomedical signal having multiple identifiable time-sequential segments and at least one recognisable periodic signal feature, the method comprising the step of segmenting the signal using a Hidden Markov Model, the model comprising a plurality of states corresponding to successive segments of the signal; characterised in that: the segmentation is performed using only two or more states corresponding to a subset of said multiple identifiable time-sequential segments, the subset forming a part of said signal between a start and an end point, in that the position of at least one of said start and end points is estimated by reference to said periodic signal feature, and in that the segmentation is performed only on said part of said signal whose location is based on said estimated position.