The digilog model goes far beyond the "classic" monitoring of patients using portable medical devices by as well including diagnostic and therapeutic procedures performed in the patient's immediate environment. Examples are mobile laboratory diagnostics or the use of portable radiological equipment. In addition, data from typical lifestyle devices such as SmartWatches can be captured and used to validate or even supplement medical data.
To meet this heterogeneity of data-collecting endpoints, digilog relies on an equally heterogeneous, distributed architecture of data stores:
- Registering, querying and retrieving data via transactions defined in the IHE Cross-Enterprise Document Sharing (XDS) integration profile : data is stored as documents in a standard IHE XDS platform;
- providing and retrieving data as HL7 FHIR Observation Resources : An IoT hub and standardized REST interfaces allow granular data (eg single lab values) to be written to a standard FHIR store;
- Linking existing IHE XDS Document Repositories: Existing data stores can be connected transparently, given that the data is registered to the digilog Document Registry. This method is currently being used to make key sequences of ultrasound exams from GE-hosted cloud storage available to digilog.
A special feature of the digilog platform is that access to the data is always possible via the interfaces of the FHIR store as well as the XDS document management, even if the requested data has been stored in the respective other storage system. Examples for the benefits of using such an abstraction of storage and access logic are:
- The results of a long-term ECG are written as a structured document to the XDS document managing system. Physicians can retrieve generated findings as PDF files via the XDS interface. Via the FHIR interface, the individual measurements coded in the document can be queried and subsequently correlated with other data. Renderings of specific forms of presentation can also be realized in this way (see graphic below for the representation of an ECG in the digilog doctors’ cockpit);
- Data from personal medical devices are written to the FHIR store via the IoT hub. Such data are stored as individual values and can be queried as such from the FHIR store via REST interfaces. Existing hospital information systems acting in the role of an IHE Document Consumer can also retrieve this data via the IHE interface as a dynamically generated PDF or structured CDA document.
All software modules developed for digilog run within their own Docker containers. This makes it easy to deploy the same component either within the eHealth center, an external data center, or a cloud infrastructure, without affecting any other systems within the digilog ecosystem.