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>Observation Body Position</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>Observation 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/5.1.0/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>: 4 Apr 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"
  }]
}