1. A method comprising: converting biomedical signal data into a set of wavelet coefficients, the set of wavelet coefficients including a plurality of scales of wavelet coefficients extending from wavelet coefficients at a fine scale to wavelet coefficients at a coarse scale; identifying features of the biomedical signal data based on whether corresponding identifying features appear in at least one of the plurality of scales of wavelet coefficients; conditionally linking identified features in each of the plurality of scales of wavelet coefficients to determine a degree of severity of a biomedical condition based on the identified features of the biomedical signal data.