atr reference beat annotations
man reference beat annotations for selected beats only
q1c manually determined boundaries, annotator 1 (second pass)
q2c manually determined boundaries, annotator 2 (second pass)
qt1 manually determined boundaries, annotator 1 (first pass)
qt2 manually determined boundaries, annotator 2 (first pass)
pu automatically determined boundaries (based on both signals)
pu0 automatically determined boundaries (based on signal 0 only)
pu1 automatically determined boundaries (based on signal 1 only)