Medical Device Interoperability

Purpose

Enable safe and standards-aligned interoperability: HL7 FHIR/IHE profiles, data formats, terminology mapping, and API design for medical data exchange.

When to Apply

• •Designing or updating device APIs, data exchange, or integrations with HIS/EMR/cloud.
• •Handling PHI or clinical decisions based on exchanged data.

Requirements (testable)

1. •Standards Use: Prefer established standards (HL7 FHIR, HL7 v2 where applicable, IHE profiles) for relevant data flows; document conformance. Rationale: interoperability and clarity.
2. •Terminology: Use standard vocabularies (SNOMED CT, LOINC) for clinical concepts; map device codes to standard codes. Rationale: semantic consistency.
3. •Data Integrity: Validate messages (schema/length/range); apply checksums/hashes over payloads where appropriate; reject/flag invalid data. Rationale: correctness.
4. •Security & Privacy: Protect PHI with TLS 1.3+; enforce authz (scopes/roles); log access; minimize data shared. Rationale: confidentiality/integrity.
5. •Error Handling: Provide clear, standard error responses; fail safe; no silent truncation. Rationale: predictable integration.
6. •Traceability: Log message IDs, timestamps, and correlation IDs; link to requirements/tests; keep audit for safety-relevant exchanges. Rationale: accountability.
7. •Interop Risks: Document interop-related hazards (misinterpretation, time sync, version mismatch) and mitigations. Rationale: safety.

Recommended Practices

• •Provide versioned APIs and explicit capability statements (e.g., FHIR CapabilityStatement).
• •Time-sync devices (NTP/PTP) to avoid timestamp drift in clinical workflows.
• •Use contract tests against partner systems; include negative cases.
• •Avoid custom extensions unless necessary; document them clearly.

Patterns

FHIR-like JSON validation (pseudo):

# REQ-INTOP-VALID-01; TEST-INTOP-04
def validate_observation(obs: dict) -> bool:
    required = ["resourceType", "status", "code", "subject", "effectiveDateTime"]
    if obs.get("resourceType") != "Observation":
        return False
    return all(k in obs for k in required)

Terminology mapping table (YAML):

# REQ-INTOP-TERM-02
device_code: FLOW_RATE
loinc: 8310-5
display: Infusion flow rate

Error response:

// REQ-INTOP-ERR-03; TEST-INTOP-07
{ "error": "invalid-parameter", "detail": "missing code" }

Anti-Patterns (risks)

• •Custom proprietary formats without mapping -> risk: misinterpretation by HIS/EMR.
• •Sending PHI over plaintext or weak TLS -> risk: data breach.
• •Silent acceptance of invalid messages -> risk: wrong clinical decisions.
• •No time sync -> risk: misleading timestamps in therapy/diagnostics.

Verification Checklist

• • Standards selected and documented; conformance statements present.
• • Terminology mapped to SNOMED/LOINC (or applicable); mappings versioned.
• • Message validation implemented; invalid data rejected/logged.
• • TLS 1.3+ and authz enforced; PHI minimized; access logged.
• • Error responses clear and standard; no silent truncation.
• • Interop hazards documented with mitigations/tests.
• • Time synchronization implemented and monitored.

Traceability

• •Requirements REQ-INTOP-### linked to contract/interop tests TEST-INTOP-###; logs maintain correlation IDs for message tracing.

References

• •HL7 FHIR R4/R5; HL7 v2 where applicable.
• •IHE profiles relevant to devices (e.g., PCD-01, DEC).
• •FDA interoperability guidance (2017).
• •IEC 62304/ISO 14971 for risk integration.

Changelog

• •1.0.0 (2026-01-04): Initial interoperability skill with standards use, validation, terminology, and security guidance.

Audit History

• •2026-01-04: Audit performed. Verified:
  • •HL7 FHIR R4/R5 references accurate
  • •IHE profiles (PCD-01, DEC) correctly mentioned
  • •FDA interoperability guidance (2017) reference verified
  • •SNOMED CT and LOINC terminology references appropriate