FHIR Observation Usage

PressureAI posts FHIR R4 Observation resources to the hospital EHR. The code system URI on this page appears in Observation.code.coding.system.

CodeSystem Resource

{
  "resourceType": "CodeSystem",
  "id":           "pai-risk",
  "url":          "https://docs.prelego.ai/pressureai/",
  "version":      "1.0.0",
  "name":         "PressureAIRiskCode",
  "title":        "PressureAI Risk Stratification Code System",
  "status":       "active",
  "content":      "complete",
  "concept": [
    { "code": "green",   "display": "Low Risk"          },
    { "code": "amber",   "display": "Elevated Risk"     },
    { "code": "red",     "display": "High Risk"         },
    { "code": "no-data", "display": "Insufficient Data" }
  ]
}

Example Observation Resource

{
  "resourceType": "Observation",
  "status": "final",
  "category": [{
    "coding": [{
      "system":  "http://terminology.hl7.org/CodeSystem/observation-category",
      "code":    "survey"
    }]
  }],
  "code": {
    "coding": [{
      "system":  "https://docs.prelego.ai/pressureai/",
      "code":    "amber",
      "display": "Elevated Risk"
    }],
    "text": "PressureAI Risk Score"
  },
  "subject":           { "reference": "Patient/example-123"   },
  "effectiveDateTime": "2026-04-09T08:30:00Z",
  "performer":         [{ "reference": "Device/pressureai-v1" }],
  "valueCodeableConcept": {
    "coding": [{
      "system":  "https://docs.prelego.ai/pressureai/",
      "code":    "amber",
      "display": "Elevated Risk"
    }]
  }
}

Element Binding

FHIR Element	Value
Observation.code.coding.system	https://docs.prelego.ai/pressureai/
Observation.code.coding.code	green | amber | red | no-data
Observation.status	final (all outputs are finalised at the time of posting)
Observation.performer	Reference to the PressureAI Device resource
Observation.subject	Reference to the Patient resource