querying-terminology-service

Querying a Terminology Service

OpenMed deliberately bundles no restricted vocabulary — no SNOMED CT, RxNorm, LOINC, ICD-10, UMLS. So when an OpenMed entity span needs a validated code (the grounding step exporting-to-fhir references), you call a FHIR terminology server the user already operates, with their own license. This skill is the thin client the coding skills lean on.

When to use

Use it whenever a span must become a coded CodeableConcept, when you need to confirm a code is valid in a system, expand a ValueSet for a picklist, look up a display, or map between vocabularies. Triggers: "terminology server", "$validate-code", "$expand", "ValueSet", "ECL", "is this a valid SNOMED/LOINC/ RxNorm code", "translate ICD-10 to SNOMED". It sits between OpenMed NER and exporting-to-fhir.

Bring your own server

The four operations are standard FHIR; point the client at whichever server the user is licensed for:

• Ontoserver (CSIRO) — production SNOMED CT/LOINC, full ECL.
• HAPI FHIR terminology module — self-hosted.
• tx.fhir.org — HL7 public server (open content only; not for licensed SNOMED/full LOINC, and not for PHI).

OpenMed never ships or proxies these — the credentials and content are the user's.

The four operations

POST [tx]/CodeSystem/$validate-code   -> is this code valid in this system?
POST [tx]/ValueSet/$expand            -> enumerate the codes in a value set
POST [tx]/CodeSystem/$lookup          -> display + properties for a code
POST [tx]/ConceptMap/$translate       -> map a code from one system to another

$validate-code — confirm before you emit

curl -s -X POST 'https://tx.example/fhir/CodeSystem/$validate-code' \
  -H 'Content-Type: application/fhir+json' -d '{
    "resourceType": "Parameters",
    "parameter": [
      {"name": "url",  "valueUri":  "http://snomed.info/sct"},
      {"name": "code", "valueCode": "44054006"},
      {"name": "display", "valueString": "Diabetes mellitus type 2"}
    ]}'
# -> Parameters: { result: true, display: "Diabetes mellitus type 2" }