description: The amount of time the individual was exposed to the Substance. package_name: hl7.fhir.core derivation: constraint name: exposureDuration type: Extension elements: extension: {index: 0} url: type: uri pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/openEHR-exposureDuration'} index: 1 valueDuration: {type: Duration, index: 2} package_version: 3.2.0 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/openEHR-exposureDuration base: http://hl7.org/fhir/StructureDefinition/Extension version: null