description: This profile represents the constraint applied to the Quantity data type by the PS-ON project to use UCUM as the code system for units. Informed by the constraints of the [Observation-Quantity-UV-IPS profile](http://hl7.org/fhir/uv/ips/StructureDefinition-Quantity-uv-ips.html).
package_name: ca.on.oh.patient-summary
derivation: constraint
name: QuantityPSON
type: Quantity
elements:
  system:
    short: UCUM system for units
    pattern: {type: Uri, value: 'http://unitsofmeasure.org'}
    mustSupport: true
    index: 0
  code: {mustSupport: true, index: 1}
package_version: 0.11.0
class: complex-type
kind: complex-type
url: http://ontariohealth.ca/fhir/StructureDefinition/ca-on-ps-profile-quantity
base: http://hl7.org/fhir/StructureDefinition/Quantity
version: 0.10.0
required: [system, code]