DICOM PS3.3 2021e - Information Object Definitions
A.34.16.4.2 Waveform Sequence and Number of Waveform Channels

The number of Waveform Sequence (5400,0100) items is unconstrained.

Note

If the total number of Waveform Channels is one the Respiratory Waveform IOD could be used instead

DICOM PS3.3 2021e - Information Object Definitions