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

The majority of PCD devices use vendor-specific or proprietary nomenclatures and terminologies. As a result, even though information may be exchanged using standards-based transactions such as Device Enterprise Communication, semantic interoperability is not achieved until the content is mapped to a standard nomenclature. This mapping is often inconsistent and subject to loss of information (e.g. mapping from a specific term to a more generic term). Also given the lack of tooling, utilizing standardized medical device terminology in production systems is difficult and often cost prohibitive.

This profile will focus on identifying a core set of semantics that are shared between multiple devices within the same modality (e.g., physiological monitors, ventilators, infusion pumps, etc.) and then mapping them to a standard terminology. The RTM mapping effort will initially include numeric parameters and their associated units of measurement and enumerated values.

The RTM information should be represented in a uniform manner, such as by one or more XML files. This will facilitate use by production systems, but more importantly, facilitate comparison between vendors that have (or plan to) implement the nomenclature standard in their systems, with the following goals:

• identify terms that are missing from the standard nomenclature
• ensure correct and consistent use if multiple representations are possible
• ensure correct and consistent use of units-of-measure
• ensure correct and consistent use of enumerated values

During the development of the RTM, gaps in the standardized medical device terminology will be identified. In these cases, proposals will be made for adding the semantics to the appropriate terminologies. Although the immediate focus of the RTM profile will be to standardize the content in transaction profiles such as DEC, which are typically between a device data gateway and enterprise level applications, the standardized terms should also support direct device communication, enabling semantic interoperability literally from the sensor to the EHR.

The availability of the RTM information will also facilitate development of tools that can more rigorously validate messages, such as enforcing the use of the correct units-of-measure and correct enumerated values associated with specific numeric values. For example, ST segment deviation will be expressed in "uV" or "mV", rather than the traditional "mm". This will promote greater interoperability, clarity and correctness which will in turn benefit patient safety.

The consistent and correct use of a standard nomenclatures such as ISO/IEEE 11073-10101 and UCUM for medical device and system data exchange will facilitate further development of real-time clinical decision support, smart alarms, safety interlocks, clinical algorithms, data mining and other clinical research. This work can be also be expanded at a future date to support events and alarms, waveforms, device settings and other critical monitoring information.

3. Key Use Case

A patient is monitored at home. A potentially life-threatening cardiac event is detected and reported to a remote monitoring service that confirms and forwards the event to his caregiver. The patient is subsequently admitted to the ER complaining about chest pain. A diagnostic 12-lead is taken followed by continuous vital signs monitoring or telemetry for further observation. Following a series of premonitory episodes of ST segment deviation, the patient exhibits short runs of ventricular ectopy that rapidly devolve into ventricular tachycardia and then fibrillation. The patient is cardioverted in the ER and scheduled for CABG surgery. During surgery, the patient is connected to well over a dozen medical devices (e.g. multiparameter patient monitor, anesthesia machine, multiple infusion pumps, bypass machine, etc.) and the data from these devices and systems is displayed in a unified and comprehensible manner and automatically charted. After successful surgery, the patient is monitored in the ICU. The patient is discharged a week later to continue his recovery at home, where, among other things, he uses a spirometer with a low-cost wireless interface to facilitate recovery. He also exercises while walking around in and outside the house attached to a wireless sensor that records and transmits his ECG via his cell phone to a remote monitoring service. The patient also has follow-up visits to cardiac rehab, where his ECG and glucose measurements are taken before and after exercise, with all the data also electronically recorded. This information is ultimately stored in the patient's personal health record and made available for a follow-up study regarding the cardiac medications he was taking.

The key point of this overly broad but realistic use case is that the patient's data is "touched" by well over three dozen medical devices and systems designed and manufactured by nearly an equal number of different vendors. An essential first step towards achieving interoperability across all these devices and systems is that they use a shared semantic foundation.

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.

The ‘Unified Code for Units of Measure’ (UCUM), [1].

5. Discussion

1. Detailed mapping content should not be included in the RTM profile document, but in separate files that could be more easily updated and manipulated.
2. Issue: Addressing gaps and having them quickly addressed by the appropriate standards organization
3. ...