<Observation xmlns="http://hl7.org/fhir">
    <id value="demo-spiro-mbr-1-2" />
    <status value="final" />
    <!-- 
20150-9   FEV1	19868-9    Forced vital capacity [Volume] Respiratory system by Spirometry      L	19926-5 - FEV1/​FVC	33452-4  - Maximum expiratory gas flow Respiratory system airway

 -->
    <code>
        <coding>
            <system value="http://loinc.org" />
            <code value="19868-9" />
            <display value="Forced vital capacity [Volume] Respiratory system by Spirometry" />
        </coding>
    </code>
    <subject>
        <reference value="Patient/demo-patient-1" />
    </subject>
    <effectiveDateTime value="2018-03-12" />
    <valueQuantity>
        <value value="4.356" />
        <system value="http://unitsofmeasure.org" />
        <code value="L" />
    </valueQuantity>
</Observation>