description: Extension to represent cardiac implantable device(s) which generated the observation. package_name: hl7.fhir.uv.cardx-cied derivation: constraint name: CIEDDeviceExtension type: Extension elements: extension: {index: 0} url: pattern: {type: uri, value: 'http://hl7.org/fhir/uv/cardx-cied/StructureDefinition/cied-device-extension'} type: uri index: 1 value: choices: [valueReference] index: 3 valueReference: type: Reference choiceOf: value refers: ['http://hl7.org/fhir/uv/cardx-cied/StructureDefinition/cied-device'] index: 4 package_version: 1.0.0-ballot extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/uv/cardx-cied/StructureDefinition/cied-device-extension base: http://hl7.org/fhir/StructureDefinition/Extension version: 1.0.0-ballot