PCD Brief Profile Proposal 2008 WCM

1. Proposed Workitem: Waveform Communication Management [WCM]

• Proposal Editor: Ken Fuchs
• Editor: TBD
• Date: N/A (Wiki keeps history)
• Version: N/A (Wiki keeps history)
• Domain: Patient Care Device

2. The Problem

Waveform data is an important component of information coming from medical patient care devices. This information can be an important complement to assessing the current status of a patient or the status of a patient during a clinical event. As such waveform information can be provided in a number of forms:

• waveform snapshots
  • specific forms of snapshots such as 12-lead ECG associated with a diagnostic encounter
  • general snapshots of waveforms captured during a clinical event or due to a request by a clinician
• continuous waveforms
  • a continuous "real-time" stream of waveform data that would be used for a remote "real-time" waveform display

Independent of the form of waveform, the following information must be accommodated:

• waveform type (e.g. ECG, Arterial Blood Pressure, CO2, etc.)
• sampling rate
• start time
• event time
• scaling (e.g. #bits/mmHg in the case of blood pressure)
• annotations (e.g. pacer, beat-label, QRS, respiration, out-of-range, etc.)
• status (e.g. lead-off, out-of-range, test mode, etc.)
• filter status (e.g. low-pass, high-pass, etc.)
• number of waveform samples
• suggested waveform display color
• units of measure
• patient identification
• clinician notes

A waveform snapshot may also include encapsulated vitals signs and event related information. The real-time waveform probably has this information as part of DEC or ACM data stream.

3. Key Use Case

1. A patient enters the Emergency Room complaining of pressure on the chest wall. A 12-lead ECG is obtained and transmitted to the Cardiology Management System. The data is reviewed and annotated and sent via WCM to the hospital Clinical Information System as part of the patient's clinical record.
2. A patient, post Heart Attack, is walking in his room while being monitored using a patient telemetry system. The system detects a run of ventricular beats and generates an alarm at the central nurse station. In parallel the alarm information, including a waveform snapshot, is communicated to a separate alarm communication system which send the alarm, vital signs and a waveform snapshot to a caregiver's portable device.
3. A physician starting his rounds would like to review the waveforms and associated data for a patient under his/her care. He/she accesses a real-time archive which has stored the continuous waveforms and related vital signs and other parameter data over the past 24 (or more) hours.

4. Standards & Systems

• ISO/IEEE 11073-10101 Health informatics — Point-of-care medical device communication — Part 10101: Nomenclature, First edition, 2004-12-15. ISO and IEEE, 2004.
• ISO/IEEE 11073-10201
• The Code for Units of Measure' (UCUM)
• Health Level 7, version 2.5 (which supports large observation messages) (IHE PCD Waveforms using HL7 V2 OBX)

5. Discussion

Use Case 1 - there are already DICOM based IHE profiles to support the transmission of 12 Lead ECG Data. During the Oct. 2008 F2F it was decided that 12 Lead Rest ECG reports would be out of scope for this profile.

Use Case 2 - a basic decision needs to be made whether these types of applications require 'raw data' or images such as jpeg files. This scenario is closely related to work being done on the ACM Profile. During the Oct. 2008 F2F it was decided that 'raw data' would be the best way of transferring this type of data. This is the best way of supporting very widely varying display sizes, form factors, pixel areas, etc.

Use Case 3 - this Use Case is related to the Real-Time Archival (& Retrieval) Management (RAM) Profile. We also need a discussion concerning whether this should be resolved as part of the DPI profile or whether we need a DEC version of this functionality as well.