Medical Device Communications Testing Project

The reality that medical devices may need to communicate with tens, if not hundreds, of other devices of varying makes, models, and modalities has not only large market implications but may result in life or death scenarios. Acute point-of-care settings such as a hospital's intensive care unit or patient's bedside require each class of medical device to use the same terminology and data organization to seamlessly and reliably communicate physiological data.

To meet this critical healthcare need point of care medical device communication standards that address plug-and-play medical device interoperability are under development. NIST researchers are collaborating with medical device experts to facilitate the development and adoption of standards for medical device communications throughout the healthcare enterprise as well as integrating it into the electronic health record.

NIST researchers have developed test tools and corresponding electronic representation of an international standard's information model that provides several important capabilities leading toward device interoperability.

Why Test?

In a recent survey conducted by Healthcare Information and Management Systems Society (HIMSS), the respondents identified “cross enterprise sharing of patient care device data” as one of their highest priorities. Goals established to meet this priority include shortening decision time, increasing productivity, minimizing transcription errors, and investing in and developing ways to correctly define and interpret the data exchanged. To meet such goals of sharing patient care information, data communication among medical devices and clinical information systems is necessary as point-of-care devices are often the primary source (or destination). Conformance and interoperability testing of medical device data communication is essential leading to long term value propositions which include:

• Integrity of data – automatic population of all information systems – reducing medical errors,
• Automating systems to capture clinical data into Electronic Health Records (EHRs) thus saving time for clinicians,
• Improving agility of enterprises to meet varied patient loads,
• Improving life-cycle cost of ownership,
• Access to patient data across devices and systems so custom communication interfaces can be eliminated thus allowing for best of breed and even plug-and-play devices.

This project consists of a standards-based schema and test tool developed by NIST researchers to assist medical device domain experts. Please use of these public domain and freely available resources.

Collaboration

The Information Technology Laboratory (ITL) within the Department of Commerce's National Institute of Standards and Technology (NIST) is collaborating with:

• The International Organization for Standardization/Institute of Electrical and Electronics Engineers, Inc. (ISO/IEEE 11073 (X73) Medical Device Communications
• The Integrated Health Enterprise - Patient Care Devices (IHE-PCD) domain working groups.
• The Personal Health Devices (PHD) working group.

We are engaged with the medical device industry and provide resources to develop conceptual information-based frameworks and test tools that ensure device implementations are conformant to medical device standards. This effort ultimately contributes to high priority needs to reduce medical errors, promote patient safety and provide accurate information into electronic medical and health record systems.

NIST is an active member in both the IHE-PCD and X73 working groups in order to understand needs, requirements (with regard to testing), and develop test methods to help promote a standards based approach. Our XML schema and test tools were, and are, developed (in part) to contribute to the momentum of the IHE-PCD domain. Our methodology is built upon the base medical device communication standard ISO/IEEE X73.

Medical Device Information Model

A foundational information component of our medical device testing efforts consists of a standards-based schema developed by NIST researchers to assist medical device domain experts. Central to our approach is a standards-based information model written in XML. The electronic equivalent of the ISO/IEEE 11073 Domain Information Model (DIM) enables the representation of medical devices and Implementation Conformance Statements (ICSs). The abstract representation is used to capture medical device implementation details by specifying exactly which features are implemented by a medical device.

Conformance statements, produced by device manufactures and implementers, provide an effective way to increase the likelihood of communicating data correctly. Data must be consistently represented syntactically and semantically for the successful interpretation of medical devices over varying makes and models. A common representation of the base information model is also essential for two or more devices to achieve any level of interoperability.

The NIST developed XML Schema has been accepted by the IEEE to become a normative addition to the ISO/IEEE 11073 Domain Information Model as part 10202. Work on the XSchema is on-going within the X73 working group. Participation and contributions to the working group is welcomed and encouraged to provide a comprehensive and industry vetted information source.

Download XML Schema file(s).

Test Tools

NIST is has developed an Implementation Conformance Statement (ICS) generator tool called ICSGenerator to facilitate creation of vendor conformance statements that would be applicable to testing a particular ISO/IEEE 11073 (X73) device. Additionally, NIST has completed initial development of a ValidatePDU tool, a tool that provides basic syntax and structure check and low level semantic checks for one or more captured messages. Both tools utilize the electronic representation of the X73 standard's information model implemented by NIST researchers in the form of an XML schema. These tools (and information model) are publicly and freely available.

Central to our approach is a capability of the ICSGenerator tool which provides an interface to easily develop and produce implementation conformance statements (ICSs). Users such as medical device vendors, manufacturers, and clinical engineers execute the tool to produce statements which disclose details of a specific implementation and specify the features provided by a particular medical device (i.e., a device profile). Device ICSs, based on, and required by, the ISO/IEEE X73 standard, can subsequently be compared and utilized across device interfaces to help overcome the semantic interoperability problem that is so prevalent today and has prevented proliferation of plug-and-play interoperable solutions. Device profiles can also be used in conjunction with messages from/to devices to determine conformance and validity to standards. Using our X73 PDU validation tool, a determination of not only the correctness of the X73 message, but compliance to the user defined profile (derived via the ICSGenerator tool) can be determined. Medical device test message generation is also possible to enable future manager/agent conformance test scenarios.

Current Tools:

• Rosetta Terminology Mapping Management System (RTMMS)
• NIST v2 Devices Tool