Version 1.0.0-rc

Date: 29.01.2026

All extensions and changes to the specification are either based on the regular project plan (e.g. adding further domains) or on feedback received during the ballot period of version 0.1.0-ballot.

• feature Lung Function Testing: Added new MIVs, profiles, operations descriptions, and examples for domain Lung Function Testing.

• feature Blood Pressure Monitoring: Added new MIVs, profiles, operations descriptions, and examples for domain Blood Pressure Monitoring.

• fix Pairing: Consent validity may be longer than the prescription period of the DiGA; therefore, the DiGA must check both. Sequence diagrams for request authorization were corrected accordingly.

• fix Continuous Glucose Measurement: Updated links to the current version (1.0.0 – STU 1) of the HL7 CGM profiles.

• fix Security and Privacy: Corrected the requirements on log downloads (esp. TLS instead of mTLS).

• fix Use of HL7 FHIR: Some examples had been hard coded into the documentation and therefore were not validated by the IG Publisher. All examples are now provided as FSH and are validated during the build process.

• fix Use of HL7 FHIR: Must Support was further relaxed to cover situations where requested data elements are managed by a third-party system and therefore may not be available to a Device Data Recorder.

• fix Retrieving Data: A request for aggregated data that would result in an empty bundle MUST return an OperationOutcome with an error or warning message. The original text incorrectly stated that an empty bundle should be returned.

• fix Retrieving Data: If a search for Observations goes too far back in the past, it does not return a 404 but instead returns a 200 with a bundle containing an OperationOutcome with an error message.

• fix Information Model: Attributes of the Device Data Recorder (e.g. delay-from-real-time) are defined per MIV. The original text incorrectly suggested that these attributes are globally defined for all MIVs supported by a Device Data Recorder.

• fix Information Model: It was previously suggested that the attributes (Grace-Period, etc.) could be queried via an API. This is incorrect. According to the HIIS-VZ specification, the attributes are part of the resource (via extension).

• improve Pairing: Clarified that the DiGA backend must check on a daily basis whether the consent or prescription period associated with a Pairing ID is still valid.

• improve Pairing: Removed the requirement for a Pairing ID to be "random", keeping only the requirement that it be "sufficiently long and unpredictable".

• improve Security and Privacy: Rephrased the authorization requirements in the "Authorization of the DiGA" section for better clarity and consistency. The conditions for granting access are now presented as conjunctive requirements that must all be fulfilled.

• improve Certification Relevant Systems: Improved clarity by explicitly mentioning that the figure illustrates the data-flow in the personal health device ecosystem. Updated figure caption and cross-references for consistency.

• improve Information Model, Retrieving Data: Cardinality of Device.definition changed from 1..1 to 0..1 to further align with existing FHIR profiles for medical devices.

• improve Retrieving Data: Attribute chunk-time-span was changed from an externally visible configuration item to a solely internal value at the Device Data Recorder because the DiGA can derive this value from the sampled Observation data.

• improve Retrieving Data: Clarified creation of a new Device.id when a Personal Health Device is exchanged (must follow FHIR LogicalIDs), and clarified handling of overlapping Device resources — options for keeping both devices active, or setting the old device to inactive when the new device is paired/activated; added guidance to check DeviceMetric.calibration.state and to delay deactivation of the old device until the new device is calibrated when relevant.

• improve Security and Privacy: CT validation was skipped for DiGA because only Device Data Recorders need validated CTs for secure mTLS.

• improve Security and Privacy: Added recommendations for caching times in test environments.

• improve Security and Privacy: Clarified that audit logs must be restricted to information necessary for audit and security purposes, and MUST NOT include personal data identifying the patient.

• improve Information Model: At the end of 2025, BfArM published the HIIS-VZ specification including the DeviceDefinition profiles. References to these profiles were added to the HDDT specification, and statements about the attributes were aligned with the HIIS-VZ information model.

• improve Operational Requirements: Strict requirements about response times were removed. Vendors should apply a best-effort approach.

• improve Blood Glucose Measurement, Blood Pressure Monitoring, Continuous Glucose Measurement, Lung Function Testing: Added an explicit statement that manufacturers of Device Data Recorders MUST implement requirements expressed by RFC 2119 keywords (MUST, SHOULD, MAY, etc.).

• improve Error Codes, FHIR Resource Server - Device, FHIR Resource Server - DeviceMetric, FHIR Resource Server - Observation: Removed usage of HTTP 403 Forbidden for authorization failures. Endpoints MUST return 401 Unauthorized for missing/invalid authentication and 404 Not Found when a resource does not exist or is not accessible due to scope/authorization restrictions.

• documentation Pairing: Added clearly defined scenarios and conditions under which the DiGA and a Device Data Recorder must be unpaired.

• documentation Certification Relevant Systems: Updated Example 5 to clarify that manufacturers must make rtCGM data from their own devices and from third-party vendors available to other DiGA via the HDDT interface.

• documentation Error Codes: Added a dedicated page about error handling, including a condensed list of all error codes.

• documentation HIMI DiGA API: Added a dedicated section about search parameters that MUST be supported by FHIR Resource Server implementations.

• documentation Information Model: The section about Device Data Recorder attributes was moved to the Information Model and rewritten for better clarity.

• documentation Operational Requirements: Deleted chapter 3.3 (Reference implementation) and added information about test support to chapter 3.2.

• documentation Pairing: Clarified the building rules for the pairingID (MUST be specific to the user account of the Device Data Recorder).

• documentation General Considerations: Clarified why version 1.0.0 of the HDDT specification only supports a subset of the contents mentioned in § 374a SGB V.

• documentation Retrieving Data: Added minor clarifications regarding aggregated data with a clearer focus on clinical metrics from continuous measurements.

• documentation Methodology: Clarified the use of the term metric to distinguish between clinical metrics and device metrics.

• documentation General Considerations: Added clarification about the origin and use of the DiGA-ID.

• documentation Operational Requirements: Clarified that strict rules about service times do not apply to unscheduled, security-related hot fixes.

• documentation Retrieving Data: Added examples for various ways to include code arguments in queries for Observation resources.

• documentation Use of HL7 FHIR: Clarified that Observation.device SHOULD NOT refer to a DeviceMetric resource for devices that do not require calibration.

• documentation Pairing: Clarified that a DiGA may request access to resources of multiple MIVs and that the Pairing-ID must remain stable in such cases.

• documentation Information Model: Clarified that the term interoperable value may represent multiple data points and may reference other interoperable values.

• documentation Glossary: Added minor corrections and extensions to the glossary.

• documentation General: Corrected typographical errors and formatting issues throughout the specification.