<StructureDefinition xmlns="http://hl7.org/fhir">
  <url value="https://example.org/fhir/StructureDefinition/MyObservation" />
  <name value="MyObservation" />
  <status value="draft" />
  <fhirVersion value="4.0.1" />
  <kind value="resource" />
  <abstract value="false" />
  <type value="Observation" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Observation" />
  <derivation value="constraint" />
  <differential>
    <element id="Observation.subject">
      <path value="Observation.subject" />
      <type>
        <code value="Reference" />
        <targetProfile value="https://example.org/fhir/StructureDefinition/MyPatient" />
      </type>
    </element>
    <element id="Observation.component.referenceRange">
      <path value="Observation.component.referenceRange" />
      <contentReference value="http://hl7.org/fhir/StructureDefinition/Observation#Observation.referenceRange" />
    </element>
  </differential>
</StructureDefinition>