 waveform records within a clinical time range
   rdsamp          - Read signal files of WFDB records
   sortann         - Rearrange annotations in canonical order
   sqrs            - Finds the QRS complexes of a WFDB ECG record signal
   surrogate       - Generates amplitude adjusted phase shuffled surrogate time series
   sumann	        - Summarize the contents of a WFDB annotation file
   tach            - Calculates instantaneous heart rate of a WFDB ECG record signal
   visgraph        - Visibility Gr