<StructureDefinition xmlns="http://hl7.org/fhir">
  <url value="https://example.org/fhir/StructureDefinition/MyObservation" />
  <name value="MyObservation" />
  <status value="draft" />
  <fhirVersion value="3.0.2" />
  <kind value="resource" />
  <abstract value="false" />
  <type value="Observation" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Observation" />
  <derivation value="constraint" />
  <differential>
    <element id="Observation.identifier">
      <path value="Observation.identifier" />
      <max value="0" />
    </element>
    <element id="Observation.basedOn">
      <path value="Observation.basedOn" />
      <max value="0" />
    </element>
    <element id="Observation.status">
      <path value="Observation.status" />
      <fixedCode value="headacheType" />
    </element>
    <element id="Observation.category">
      <path value="Observation.category" />
      <min value="1" />
      <max value="1" />
    </element>
    <element id="Observation.category.coding">
      <path value="Observation.category.coding" />
      <min value="1" />
      <max value="1" />
    </element>
    <element id="Observation.category.coding.system">
      <path value="Observation.category.coding.system" />
      <min value="1" />
      <fixedUri value="http://terminology.hl7.org/CodeSystem/observation-category" />
    </element>
    <element id="Observation.category.coding.version">
      <path value="Observation.category.coding.version" />
      <max value="0" />
    </element>
    <element id="Observation.category.coding.code">
      <path value="Observation.category.coding.code" />
      <min value="1" />
      <fixedCode value="survey" />
    </element>
    <element id="Observation.category.coding.display">
      <path value="Observation.category.coding.display" />
      <max value="0" />
    </element>
    <element id="Observation.category.coding.userSelected">
      <path value="Observation.category.coding.userSelected" />
      <max value="0" />
    </element>
    <element id="Observation.category.text">
      <path value="Observation.category.text" />
      <max value="0" />
    </element>
    <element id="Observation.code.coding">
      <path value="Observation.code.coding" />
      <min value="1" />
      <max value="1" />
    </element>
    <element id="Observation.code.coding.system">
      <path value="Observation.code.coding.system" />
      <min value="1" />
      <fixedUri value="http://loinc.org" />
    </element>
    <element id="Observation.code.coding.version">
      <path value="Observation.code.coding.version" />
      <max value="0" />
    </element>
    <element id="Observation.code.coding.code">
      <path value="Observation.code.coding.code" />
      <min value="1" />
    </element>
    <element id="Observation.code.coding.display">
      <path value="Observation.code.coding.display" />
      <max value="0" />
    </element>
    <element id="Observation.code.coding.userSelected">
      <path value="Observation.code.coding.userSelected" />
      <max value="0" />
    </element>
    <element id="Observation.subject">
      <path value="Observation.subject" />
      <type>
        <code value="Reference" />
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/Patient" />
      </type>
    </element>
    <element id="Observation.subject.reference">
      <path value="Observation.subject.reference" />
      <min value="1" />
    </element>
    <element id="Observation.subject.identifier">
      <path value="Observation.subject.identifier" />
      <max value="0" />
    </element>
    <element id="Observation.subject.display">
      <path value="Observation.subject.display" />
      <max value="0" />
    </element>
    <element id="Observation.context">
      <path value="Observation.context" />
      <max value="0" />
    </element>
    <element id="Observation.effective[x]">
      <path value="Observation.effective[x]" />
      <max value="0" />
    </element>
    <element id="Observation.issued">
      <path value="Observation.issued" />
      <max value="0" />
    </element>
    <element id="Observation.performer">
      <path value="Observation.performer" />
      <max value="0" />
    </element>
    <element id="Observation.value[x]">
      <path value="Observation.value[x]" />
      <type>
        <code value="Quantity" />
      </type>
      <type>
        <code value="string" />
      </type>
      <type>
        <code value="dateTime" />
      </type>
      <type>
        <code value="Period" />
      </type>
    </element>
    <element id="Observation.dataAbsentReason">
      <path value="Observation.dataAbsentReason" />
      <max value="0" />
    </element>
    <element id="Observation.interpretation.coding">
      <path value="Observation.interpretation.coding" />
      <min value="1" />
      <max value="1" />
    </element>
    <element id="Observation.interpretation.coding.system">
      <path value="Observation.interpretation.coding.system" />
      <min value="1" />
      <fixedUri value="http://loinc.org" />
    </element>
    <element id="Observation.interpretation.coding.version">
      <path value="Observation.interpretation.coding.version" />
      <max value="0" />
    </element>
    <element id="Observation.interpretation.coding.code">
      <path value="Observation.interpretation.coding.code" />
      <min value="1" />
    </element>
    <element id="Observation.interpretation.coding.display">
      <path value="Observation.interpretation.coding.display" />
      <max value="0" />
    </element>
    <element id="Observation.interpretation.coding.userSelected">
      <path value="Observation.interpretation.coding.userSelected" />
      <max value="0" />
    </element>
    <element id="Observation.interpretation.text">
      <path value="Observation.interpretation.text" />
      <min value="1" />
    </element>
    <element id="Observation.comment">
      <path value="Observation.comment" />
      <max value="0" />
    </element>
    <element id="Observation.bodySite">
      <path value="Observation.bodySite" />
      <max value="0" />
    </element>
    <element id="Observation.method">
      <path value="Observation.method" />
      <max value="0" />
    </element>
    <element id="Observation.specimen">
      <path value="Observation.specimen" />
      <max value="0" />
    </element>
    <element id="Observation.device">
      <path value="Observation.device" />
      <max value="0" />
    </element>
    <element id="Observation.referenceRange">
      <path value="Observation.referenceRange" />
      <max value="0" />
    </element>
    <element id="Observation.related">
      <path value="Observation.related" />
      <max value="0" />
    </element>
    <element id="Observation.component">
      <path value="Observation.component" />
      <max value="0" />
    </element>
  </differential>
</StructureDefinition>