PCD Detailed Profile Proposal 2009 WCM
Proposed Workitem: Waveform Communication Management [WCM]
- Proposal Editor: Ken Fuchs
- Editor: TBA
- Date: N/A (Wiki keeps history)
- Version: N/A (Wiki keeps history)
- Domain: Patient Care Device
Summary
The WCM (Waveform Communication Management) Profile provides support for the communication of physiological 2-dimensional waveforms that have been digitized at regular time intervals (e.g. every 2msec for an ECG waveform). This data can then be reported using the IHE PCD WCM Profile as either a time-bounded waveform report or a continuous stream of waveform data.
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.
Key Use Cases
- A patient enters the Emergency Room complaining of pressure on the chest wall. A 12-lead ECG is obtained and transmitted via WCM 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.
- 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 the waveform, parameter data and alarm information is acquired by a separate alarm communication system which then sends the appropriate information snapshot to a caregiver's portable device.
- A physician would like to review the current status of a patient including his parameter information, waveforms, device settings, etc. He brings up an application on his PDA or personal computer and can view the current information delayed by a maximum of 10 seconds.
- A physician starting his rounds would like to review the waveforms and associated data for a patient under his/her care. He/she accesses an archive which has stored the continuous waveforms and related vital signs and other parameter data over the past 24 (or more) hours.
- A Remote Monitoring Station, responsible for checking on monitored outpatients, receives an alert on one of its patients. The alert is accompanied by a waveform snippet at the time of the event. If further investigation of the current status of the patient is required, a continuous waveform can be viewed.
- The user of an EHR requests a snapshot of a waveform from the device.
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 'Unified Code for Units of Measure' (UCUM)
- Health Level 7, version 2.5 (which supports large observation messages) (IHE PCD Waveforms using HL7 V2 OBX)
Technical Approach
We anticipate that a phased approach will be used, either focusing first on waveform snapshots and then on continuous waveforms or vice-versa. This decision will be made based on the interests of the participants.
Existing actors
The WCM profile will not use any existing actors.
New actors
Some new actors may include:
- Waveform Communications Reporter (WCR)
- Waveform Communications Consumer (WCC)
- Waveform Communications Filter (WCF)
Those familiar with the DEC profile will see the parallelism...
Existing transactions
The existing DEC profile transactions can be used as templates for the WCM transactions.
New transactions (standards used)
For waveform snapshot communications, it may be a decision of the working group to use HL7 version 3.x transactions. If that is the case, this will be the first such project within the PCD.
Impact on existing integration profiles
No modifications of existing profiles is anticipated.
New integration profiles needed
The WCM profile?
Support & Resources
The WCM Brief Profile Proposal received support from:
- Ascom Wireless
- Capsule
- Draeger Medical
- GE Healthcare
- LiveData
- Philips Healthcare
Risks
Technical risks include:
- Size of resulting HL7 messages
- Lack of participation
- ???
Political risks include:
- ???
Open Issues
- Key issue is to first choose which aspect of the profile to implement first: snapshot or continuous.
- Waveform snapshots can be expressed as either DICOM, images (such as jpeg), HL7 Version 2.x or HL7 Version 3.x transactions. A key requirement is whether 'Raw Data' is required or an image will do. (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 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 3 - this is a good example of the possible use of the WCM profile.
- Use Case 4 - this Use Case is related to the Query for Bulk Data (QBD) Profile and will be handled as such.
Tech Cmte Evaluation
<The technical committee will use this area to record details of the effort estimation, etc.>
Effort Evaluation (as a % of Tech Cmte Bandwidth):
- 35% for ...
Responses to Issues:
- See italics in Risk and Open Issue sections
Candidate Editor:
- TBA