This Observation Series type contains waveforms of a "representative beat" (a.k.a. "median beat" or "average beat"). The waveform samples are measured in relative time, relative to the beginning of the beat as defined by the Observation Series effective time. The waveforms are not directly acquired from the subject, but rather algorithmically derived from the "rhythm" waveforms.

This Observation type contains ECG "rhythm" waveforms. The waveform samples are measured in absolute time (a.k.a. "subject time" or "effective time"). These waveforms are usually "raw" with some minimal amount of noise reduction and baseline filtering applied.