InterSystems, based in Cambridge, Massachusetts, is a global software company that develops the platforms and solutions used by millions of people in 100 countries – often without their being aware of it. Clients turn to InterSystems with their toughest technological challenges in data management, interoperability and analytics.


In healthcare, one of InterSystems’ main markets, interoperability is the ultimate 21st century challenge, and FHIR is emerging as a key step in making interoperability a reality. Fast Healthcare Interoperability Resources (FHIR) is a draft standard describing data formats and elements and an application programming interface for exchanging electronic health records. The standard is being developed through the Health Level Seven (HL7) healthcare standards organization.

FHIR as a game-changer

Russell Leftwich, Senior Clinical Advisor at InterSystems and incoming HL7 board member, is clear about the relevance of FHIR to InterSystems: “RESTful interfaces based on FHIR will be a game-changer by commoditizing EHR data and reducing the cost of customized apps that providers have needed and wanted. This will open a path to innovation with apps not yet imagined,” he said.


To sharpen its understanding of the emerging FHIR standard, InterSystems partnered with Firely, a group of software engineers, support engineers and FHIR consultants, based in Amsterdam, the Netherlands.. The goal was to find the best means of integrating FHIR into InterSystems healthcare technology.

InterSystems had already identified major use cases for its flagship HealthShare health informatics platform, which is built on the InterSystems Caché database and the InterSystems Ensemble integration platform. A key topic was the way FHIR resources were to be mapped to the concept of records and objects and their identities in HealthShare.

In-house workshops

InterSystems retained Firely to conduct two in-house workshops of one week each. “Although the FHIR basics are simple enough for any experienced software developer to understand almost at a glance, the finer details and advanced technological edges of FHIR are much more quickly mastered when FHIR experts are at hand for Q&A,” said Matthew Spielman, HealthShare Product Manager at InterSystems with a focus on patient engagement and interoperability.

“It was very useful to have Firely around to discuss all the finer details that show up when you’re building an actual FHIR server. This saved our team a lot of time and helped us avoid pitfalls,” he added.

The introductory workshop included the following FHIR principles:

  • The technical background and genesis of FHIR
  • What “resources” are and how they form a web of information
  • Clinical, administrative, and infrastructural resources in FHIR
  • REST and messaging
  • Search
  • Extensions
  • Operations
  • Conformance

“Conformance” is the concept of using FHIR in a very specific way, for a chosen use case, leaving all the irrelevant parts of FHIR out. Firely elaborated on constraints and extensions on resources to help InterSystems adapt FHIR to its use cases and data models.

Working prototype

The InterSystems developers quickly adopted the FHIR way of thinking and Firely got a better understanding of the architecture of HealthShare. Together, the teams created a working prototype of mapping and storing incoming FHIR REST calls.

Indexing and searching resources

One of the harder parts of building FHIR services is “search.” Thanks to the robust and flexible technical architecture of HealthShare and Firely’s experience with implementing search in FHIR, InterSystems drew up an approach to indexing and searching resources. After the workshop concluded, this approach proved to be viable and enabled InterSystems to participate in the implementation sprints of the Argonaut project, which is leading the implementation of the FHIR standard.