DICOM PS3.17 2024a - Explanatory Information

C.6 Harmonization With HL7

This Waveform IE definition is harmonized with the HL7 waveform semantic constructs, including the channel definition Attributes and the use of multiplex groups for synchronously acquired channels. The use of a common object model allows straightforward transcoding and interoperation between systems that use DICOM for waveform interchange and those that use HL7, and may be viewed as an example of common semantics implemented in the differing syntaxes of two messaging systems.

This section describes the congruence between the DICOM Waveform IE and the HL7 version 2.3 waveform message format (see HL7 version 2.3 Chapter 7, sections 7.14 - 7.20).

C.6.1 HL7 Waveform Observation

Waveforms in HL7 messages are sent in a set of OBX (Observation) Segments. Four subtypes of OBX segments are defined:

  • The CHN subtype defines one channel in a CD (Channel Definition) Data Type

  • The TIM subtype defines the start time of the waveform data in a TS (Time String) Data Type

  • The WAV subtype carries the waveform data in an NA (Numeric Array) or MA (Multiplexed Array) Data Type (ASCII encoded samples, character delimited)

  • The ANO subtype carries an annotation in a CE (Coded Entry) Data Type with a reference to a specific time within the waveform to which the annotation applies

Other segments of the HL7 message definition specify patient and study identification, whose harmonization with DICOM constructs is not defined in this Annex.

DICOM PS3.17 2024a - Explanatory Information