An example to demonstrate using the bodyPosition and delta extensions

{
  "resourceType": "Observation",
  "id": "map-sitting",
  "text": {
    "status": "extensions",
    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\"><p><b>Generated Narrative: Observation</b><a name=\"map-sitting\"> </a></p><div style=\"display: inline-block; background-color: #d9e0e7; padding: 6px; margin: 4px; border: 1px solid #8da1b4; border-radius: 5px; line-height: 60%\"><p style=\"margin-bottom: 0px\">Resource Observation &quot;map-sitting&quot; </p></div><p><b>bodyPosition</b>: Sitting position (finding) <span style=\"background: LightGoldenRodYellow; margin: 4px; border: 1px solid khaki\"> (<a href=\"https://browser.ihtsdotools.org/\">SNOMED CT</a>#33586001)</span></p><p><b>delta</b>: Decreased (qualifier value) <span style=\"background: LightGoldenRodYellow; margin: 4px; border: 1px solid khaki\"> (<a href=\"https://browser.ihtsdotools.org/\">SNOMED CT</a>#1250004)</span></p><p><b>status</b>: final</p><p><b>category</b>: Laboratory <span style=\"background: LightGoldenRodYellow; margin: 4px; border: 1px solid khaki\"> (<a href=\"http://terminology.hl7.org/3.1.0/CodeSystem-observation-category.html\">Observation Category Codes</a>#laboratory)</span></p><p><b>code</b>: Mean blood pressure <span style=\"background: LightGoldenRodYellow; margin: 4px; border: 1px solid khaki\"> (<a href=\"https://loinc.org/\">LOINC</a>#8478-0)</span></p><p><b>subject</b>: <a href=\"patient-example.html\">Patient/example</a> &quot;Peter CHALMERS&quot;</p><p><b>encounter</b>: <a href=\"encounter-example.html\">Encounter/example</a></p><p><b>effective</b>: 2018-04-02T10:30:10+01:00 --&gt; 2018-04-05T10:30:10+01:00</p><p><b>issued</b>: 04/04/2018 12:30:10 AM</p><p><b>value</b>: 60 mm Hg<span style=\"background: LightGoldenRodYellow\"> (Details: UCUM code mm[Hg] = 'mmHg')</span></p><p><b>interpretation</b>: Below low normal <span style=\"background: LightGoldenRodYellow; margin: 4px; border: 1px solid khaki\"> (v2-0078#L &quot;Low&quot;)</span></p></div>"
  },
  "extension": [
    {
      "url": "http://hl7.org/fhir/StructureDefinition/observation-bodyPosition",
      "valueCodeableConcept": {
        "coding": [
          {
            "system": "http://snomed.info/sct",
            "code": "33586001",
            "display": "Sitting position (finding)"
          }
        ]
      }
    },
    {
      "url": "http://hl7.org/fhir/StructureDefinition/observation-delta",
      "valueCodeableConcept": {
        "coding": [
          {
            "system": "http://snomed.info/sct",
            "code": "1250004",
            "display": "Decreased (qualifier value)"
          }
        ]
      }
    }
  ],
  "status": "final",
  "category": [
    {
      "coding": [
        {
          "system": "http://terminology.hl7.org/CodeSystem/observation-category",
          "code": "laboratory",
          "display": "Laboratory"
        }
      ]
    }
  ],
  "code": {
    "coding": [
      {
        "system": "http://loinc.org",
        "code": "8478-0",
        "display": "Mean blood pressure"
      }
    ]
  },
  "subject": {
    "reference": "Patient/example"
  },
  "encounter": {
    "reference": "Encounter/example"
  },
  "effectivePeriod": {
    "start": "2018-04-02T10:30:10+01:00",
    "end": "2018-04-05T10:30:10+01:00"
  },
  "issued": "2018-04-03T15:30:10+01:00",
  "valueQuantity": {
    "value": 60,
    "unit": "mm Hg",
    "system": "http://unitsofmeasure.org",
    "code": "mm[Hg]"
  },
  "interpretation": [
    {
      "coding": [
        {
          "system": "http://terminology.hl7.org/CodeSystem/v2-0078",
          "code": "L",
          "display": "Low"
        }
      ],
      "text": "Below low normal"
    }
  ]
}