“…However, to the best of the authors’ knowledge none of these tools meet all requirements listed above. An often-encountered limitation is that they only work for one signal type—predominantly, ECG [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ] or respiration [ 15 ]. Furthermore, the list of characteristic points is predefined: a user can annotate a single fiducial (R-peak) [ 10 , 14 ] or an extended, but fixed set of points (P, Q, R, S, and T waves) [ 12 , 13 ].…”