Personal Health Device Implementation Guide
1.1.0 - STU 1.1 International flag

Personal Health Device Implementation Guide, published by HL7 International / Health Care Devices. This guide is not an authorized publication; it is the continuous build for version 1.1.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/phd/ and changes regularly. See the Directory of published versions

Resource Profile: PhdDeviceMetric - Detailed Descriptions

Draft as of 2024-11-18

Definitions for the PhdDeviceMetric resource profile.

Guidance on how to interpret the contents of this table can be found here

0. DeviceMetric
Definition

This resource contains at least an MDC type code for the observation that can be generated by the PHD.

2. DeviceMetric.extension
SlicingThis element introduces a set of slices on DeviceMetric.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
  • value @ url
  • 4. DeviceMetric.extension:Accuracy
    Slice NameAccuracy
    Control0..1
    TypeExtension(Numeric Accuracy) (Extension Type: Quantity)
    6. DeviceMetric.type
    8. DeviceMetric.type.coding
    Control1..?
    SlicingThis element introduces a set of slices on DeviceMetric.type.coding. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • value @ system
    • 10. DeviceMetric.type.coding:MDCType
      Slice NameMDCType
      Definition

      This MDC code expresses the observation type of the metric.

      ShortThe 11073-10101 MDC code for the metric
      Comments

      This information is provided by any ACOM/GHS PHD device.

      Control1..1
      12. DeviceMetric.type.coding:MDCType.system
      Control1..?
      Fixed Valueurn:iso:std:iso:11073:10101
      14. DeviceMetric.type.coding:MDCType.code
      Comments

      Required for all measurements

      Control1..?
      16. DeviceMetric.type.text
      ShortIt is recommended to display at least the reference identifier for the MDC code.
      18. DeviceMetric.unit
      Comments

      When the type of the observation is numeric or compound numeric, the unit could be filled in as well. This should be a UCUM code, but when that is not known, it can be an MDC code. This field can be updated by the gateway when an observation of the corresponding type is generated by the PHD.

      20. DeviceMetric.source
      TypeReference(PhdDevice)
      22. DeviceMetric.operationalStatus
      Comments

      For a PHD device the operational status is only known when it is communicating. It is recommended to leave this field out.

      24. DeviceMetric.category
      Comments

      When the category can be derived from the type of the DeviceMetric it can be filled in on creation. Otherwise it can be filled in by updating the DeviceMetric resource when the PHD generates an observation of that type. It can be set to #unspecified until known.

      26. DeviceMetric.measurementPeriod
      Comments

      when this information is provided by a GHS device in an Observation Schedule descriptor, it should be filled in here as well.

      Guidance on how to interpret the contents of this table can be found here

      0. DeviceMetric
      Definition

      This resource contains at least an MDC type code for the observation that can be generated by the PHD.


      Describes a measurement, calculation or setting capability of a medical device.

      ShortMeasurement, calculation or setting capability of a medical device
      Comments

      For the initial scope, this DeviceMetric resource is only applicable to describe a single metric node in the containment tree that is produced by the context scanner in any medical device that implements or derives from the ISO/IEEE 11073 standard.

      Control0..*
      Is Modifierfalse
      Summaryfalse
      Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
      dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
      dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
      dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
      dom-6: A resource should have narrative for robust management (text.`div`.exists())
      2. DeviceMetric.implicitRules
      Definition

      A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

      ShortA set of rules under which this content was created
      Comments

      Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of it's narrative along with other profiles, value sets, etc.

      Control0..1
      Typeuri
      Is Modifiertrue because This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      4. DeviceMetric.extension
      Definition

      An Extension


      May be used to represent additional information that is not part of the basic definition of the resource. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

      ShortExtensionAdditional content defined by implementations
      Comments

      There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

      Control0..*
      TypeExtension
      Is Modifierfalse
      Summaryfalse
      Alternate Namesextensions, user content
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      SlicingThis element introduces a set of slices on DeviceMetric.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
      • value @ url
      • 6. DeviceMetric.extension:Accuracy
        Slice NameAccuracy
        Definition

        The accuracy of a measurable quantity. The unit should be the same as the unit of the quantity this applies to.

        ShortNumeric Accuracy
        Control0..1
        This element is affected by the following invariants: ele-1
        TypeExtension(Numeric Accuracy) (Extension Type: Quantity)
        Is Modifierfalse
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
        ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
        8. DeviceMetric.modifierExtension
        Definition

        May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

        Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

        ShortExtensions that cannot be ignored
        Comments

        There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

        Control0..*
        TypeExtension
        Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
        Summaryfalse
        Requirements

        Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

        Alternate Namesextensions, user content
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
        10. DeviceMetric.type
        Definition

        Describes the type of the metric. For example: Heart Rate, PEEP Setting, etc.

        ShortIdentity of metric, for example Heart Rate or PEEP Setting
        Comments

        DeviceMetric.type can be referred to either IEEE 11073-10101 or LOINC.

        Control1..1
        BindingThe codes SHOULD be taken from DeviceMetricAndComponentTypeshttp://hl7.org/fhir/ValueSet/devicemetric-type
        (preferred to http://hl7.org/fhir/ValueSet/devicemetric-type)

        Describes the metric type.

        TypeCodeableConcept
        Is Modifierfalse
        Summarytrue
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        12. DeviceMetric.type.coding
        Definition

        A reference to a code defined by a terminology system.

        ShortCode defined by a terminology system
        Comments

        Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

        Control10..*
        TypeCoding
        Is Modifierfalse
        Summarytrue
        Requirements

        Allows for alternative encodings within a code system, and translations to other code systems.

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        SlicingThis element introduces a set of slices on DeviceMetric.type.coding. The slices areUnordered and Open, and can be differentiated using the following discriminators:
        • value @ system
        • 14. DeviceMetric.type.coding:MDCType
          Slice NameMDCType
          Definition

          This MDC code expresses the observation type of the metric.


          A reference to a code defined by a terminology system.

          ShortThe 11073-10101 MDC code for the metricCode defined by a terminology system
          Comments

          This information is provided by any ACOM/GHS PHD device.


          Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

          Control10..1*
          TypeCoding
          Is Modifierfalse
          Summarytrue
          Requirements

          Allows for alternative encodings within a code system, and translations to other code systems.

          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          16. DeviceMetric.type.coding:MDCType.system
          Definition

          The identification of the code system that defines the meaning of the symbol in the code.

          ShortIdentity of the terminology system
          Comments

          The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously.

          Control10..1
          Typeuri
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summarytrue
          Requirements

          Need to be unambiguous about the source of the definition of the symbol.

          Fixed Valueurn:iso:std:iso:11073:10101
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          18. DeviceMetric.type.coding:MDCType.code
          Definition

          A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

          ShortSymbol in syntax defined by the system
          Comments

          Required for all measurements

          Control10..1
          Typecode
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summarytrue
          Requirements

          Need to refer to a particular code in the system.

          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          20. DeviceMetric.type.text
          Definition

          A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user.

          ShortIt is recommended to display at least the reference identifier for the MDC code.Plain text representation of the concept
          Comments

          Very often the text is the same as a displayName of one of the codings.

          Control0..1
          Typestring
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summarytrue
          Requirements

          The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source.

          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          22. DeviceMetric.unit
          Definition

          Describes the unit that an observed value determined for this metric will have. For example: Percent, Seconds, etc.

          ShortUnit of Measure for the Metric
          Comments

          When the type of the observation is numeric or compound numeric, the unit could be filled in as well. This should be a UCUM code, but when that is not known, it can be an MDC code. This field can be updated by the gateway when an observation of the corresponding type is generated by the PHD.


          DeviceMetric.unit can refer to either UCUM or preferable a RTMMS coding system.

          Control0..1
          BindingThe codes SHOULD be taken from DeviceMetricAndComponentTypeshttp://hl7.org/fhir/ValueSet/devicemetric-type
          (preferred to http://hl7.org/fhir/ValueSet/devicemetric-type)

          Describes the unit of the metric.

          TypeCodeableConcept
          Is Modifierfalse
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          24. DeviceMetric.source
          Definition

          Describes the link to the Device that this DeviceMetric belongs to and that contains administrative device information such as manufacturer, serial number, etc.

          ShortDescribes the link to the source Device
          Control0..1
          TypeReference(PhdDevice, Device)
          Is Modifierfalse
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          26. DeviceMetric.operationalStatus
          Definition

          Indicates current operational state of the device. For example: On, Off, Standby, etc.

          Shorton | off | standby | entered-in-error
          Comments

          For a PHD device the operational status is only known when it is communicating. It is recommended to leave this field out.

          Control0..1
          BindingThe codes SHALL be taken from DeviceMetricOperationalStatushttp://hl7.org/fhir/ValueSet/metric-operational-status|4.0.1
          (required to http://hl7.org/fhir/ValueSet/metric-operational-status|4.0.1)

          Describes the operational status of the DeviceMetric.

          Typecode
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          28. DeviceMetric.category
          Definition

          Indicates the category of the observation generation process. A DeviceMetric can be for example a setting, measurement, or calculation.

          Shortmeasurement | setting | calculation | unspecified
          Comments

          When the category can be derived from the type of the DeviceMetric it can be filled in on creation. Otherwise it can be filled in by updating the DeviceMetric resource when the PHD generates an observation of that type. It can be set to #unspecified until known.

          Control1..1
          BindingThe codes SHALL be taken from DeviceMetricCategoryhttp://hl7.org/fhir/ValueSet/metric-category|4.0.1
          (required to http://hl7.org/fhir/ValueSet/metric-category|4.0.1)

          Describes the category of the metric.

          Typecode
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          30. DeviceMetric.measurementPeriod
          Definition

          Describes the measurement repetition time. This is not necessarily the same as the update period. The measurement repetition time can range from milliseconds up to hours. An example for a measurement repetition time in the range of milliseconds is the sampling rate of an ECG. An example for a measurement repetition time in the range of hours is a NIBP that is triggered automatically every hour. The update period may be different than the measurement repetition time, if the device does not update the published observed value with the same frequency as it was measured.

          ShortDescribes the measurement repetition time
          Comments

          when this information is provided by a GHS device in an Observation Schedule descriptor, it should be filled in here as well.

          Control0..1
          TypeTiming
          Is Modifierfalse
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))

          Guidance on how to interpret the contents of this table can be found here

          0. DeviceMetric
          Definition

          This resource contains at least an MDC type code for the observation that can be generated by the PHD.

          ShortMeasurement, calculation or setting capability of a medical device
          Comments

          For the initial scope, this DeviceMetric resource is only applicable to describe a single metric node in the containment tree that is produced by the context scanner in any medical device that implements or derives from the ISO/IEEE 11073 standard.

          Control0..*
          Is Modifierfalse
          Summaryfalse
          Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
          dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
          dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
          dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
          dom-6: A resource should have narrative for robust management (text.`div`.exists())
          2. DeviceMetric.id
          Definition

          The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.

          ShortLogical id of this artifact
          Comments

          The only time that a resource does not have an id is when it is being submitted to the server using a create operation.

          Control0..1
          Typeid
          Is Modifierfalse
          Summarytrue
          4. DeviceMetric.meta
          Definition

          The metadata about the resource. This is content that is maintained by the infrastructure. Changes to the content might not always be associated with version changes to the resource.

          ShortMetadata about the resource
          Control0..1
          TypeMeta
          Is Modifierfalse
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          6. DeviceMetric.implicitRules
          Definition

          A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

          ShortA set of rules under which this content was created
          Comments

          Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of it's narrative along with other profiles, value sets, etc.

          Control0..1
          Typeuri
          Is Modifiertrue because This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summarytrue
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          8. DeviceMetric.language
          Definition

          The base language in which the resource is written.

          ShortLanguage of the resource content
          Comments

          Language is provided to support indexing and accessibility (typically, services such as text to speech use the language tag). The html language tag in the narrative applies to the narrative. The language tag on the resource may be used to specify the language of other presentations generated from the data in the resource. Not all the content has to be in the base language. The Resource.language should not be assumed to apply to the narrative automatically. If a language is specified, it should it also be specified on the div element in the html (see rules in HTML5 for information about the relationship between xml:lang and the html lang attribute).

          Control0..1
          BindingThe codes SHOULD be taken from CommonLanguages
          (preferred to http://hl7.org/fhir/ValueSet/languages)

          A human language.

          Additional BindingsPurpose
          AllLanguagesMax Binding
          Typecode
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          10. DeviceMetric.text
          Definition

          A human-readable narrative that contains a summary of the resource and can be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety.

          ShortText summary of the resource, for human interpretation
          Comments

          Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.

          Control0..1
          TypeNarrative
          Is Modifierfalse
          Summaryfalse
          Alternate Namesnarrative, html, xhtml, display
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          12. DeviceMetric.contained
          Definition

          These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, and nor can they have their own independent transaction scope.

          ShortContained, inline Resources
          Comments

          This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags In their meta elements, but SHALL NOT have security labels.

          Control0..*
          TypeResource
          Is Modifierfalse
          Summaryfalse
          Alternate Namesinline resources, anonymous resources, contained resources
          14. DeviceMetric.extension
          Definition

          An Extension

          ShortExtension
          Control0..*
          TypeExtension
          Is Modifierfalse
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
          SlicingThis element introduces a set of slices on DeviceMetric.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
          • value @ url
          • 16. DeviceMetric.extension:Accuracy
            Slice NameAccuracy
            Definition

            The accuracy of a measurable quantity. The unit should be the same as the unit of the quantity this applies to.

            ShortNumeric Accuracy
            Control0..1
            This element is affected by the following invariants: ele-1
            TypeExtension(Numeric Accuracy) (Extension Type: Quantity)
            Is Modifierfalse
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
            18. DeviceMetric.modifierExtension
            Definition

            May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

            Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

            ShortExtensions that cannot be ignored
            Comments

            There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

            Control0..*
            TypeExtension
            Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
            Summaryfalse
            Requirements

            Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

            Alternate Namesextensions, user content
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
            20. DeviceMetric.identifier
            Definition

            Unique instance identifiers assigned to a device by the device or gateway software, manufacturers, other organizations or owners. For example: handle ID.

            ShortInstance identifier
            Comments

            For identifiers assigned to a device by the device or gateway software, the system element of the identifier should be set to the unique identifier of the device.

            NoteThis is a business identifier, not a resource identifier (see discussion)
            Control0..*
            TypeIdentifier
            Is Modifierfalse
            Summarytrue
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            22. DeviceMetric.type
            Definition

            Describes the type of the metric. For example: Heart Rate, PEEP Setting, etc.

            ShortIdentity of metric, for example Heart Rate or PEEP Setting
            Comments

            DeviceMetric.type can be referred to either IEEE 11073-10101 or LOINC.

            Control1..1
            BindingThe codes SHOULD be taken from DeviceMetricAndComponentTypes
            (preferred to http://hl7.org/fhir/ValueSet/devicemetric-type)

            Describes the metric type.

            TypeCodeableConcept
            Is Modifierfalse
            Summarytrue
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            24. DeviceMetric.type.id
            Definition

            Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

            ShortUnique id for inter-element referencing
            Control0..1
            Typestring
            Is Modifierfalse
            XML FormatIn the XML format, this property is represented as an attribute.
            Summaryfalse
            26. DeviceMetric.type.extension
            Definition

            May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

            ShortAdditional content defined by implementations
            Comments

            There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

            Control0..*
            TypeExtension
            Is Modifierfalse
            Summaryfalse
            Alternate Namesextensions, user content
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
            SlicingThis element introduces a set of slices on DeviceMetric.type.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
            • value @ url
            • 28. DeviceMetric.type.coding
              Definition

              A reference to a code defined by a terminology system.

              ShortCode defined by a terminology system
              Comments

              Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

              Control1..*
              TypeCoding
              Is Modifierfalse
              Summarytrue
              Requirements

              Allows for alternative encodings within a code system, and translations to other code systems.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              SlicingThis element introduces a set of slices on DeviceMetric.type.coding. The slices areUnordered and Open, and can be differentiated using the following discriminators:
              • value @ system
              • 30. DeviceMetric.type.coding:MDCType
                Slice NameMDCType
                Definition

                This MDC code expresses the observation type of the metric.

                ShortThe 11073-10101 MDC code for the metric
                Comments

                This information is provided by any ACOM/GHS PHD device.

                Control1..1
                TypeCoding
                Is Modifierfalse
                Summarytrue
                Requirements

                Allows for alternative encodings within a code system, and translations to other code systems.

                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                32. DeviceMetric.type.coding:MDCType.id
                Definition

                Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                ShortUnique id for inter-element referencing
                Control0..1
                Typestring
                Is Modifierfalse
                XML FormatIn the XML format, this property is represented as an attribute.
                Summaryfalse
                34. DeviceMetric.type.coding:MDCType.extension
                Definition

                May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                ShortAdditional content defined by implementations
                Comments

                There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                Control0..*
                TypeExtension
                Is Modifierfalse
                Summaryfalse
                Alternate Namesextensions, user content
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                SlicingThis element introduces a set of slices on DeviceMetric.type.coding.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                • value @ url
                • 36. DeviceMetric.type.coding:MDCType.system
                  Definition

                  The identification of the code system that defines the meaning of the symbol in the code.

                  ShortIdentity of the terminology system
                  Comments

                  The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously.

                  Control1..1
                  Typeuri
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Requirements

                  Need to be unambiguous about the source of the definition of the symbol.

                  Fixed Valueurn:iso:std:iso:11073:10101
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  38. DeviceMetric.type.coding:MDCType.version
                  Definition

                  The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

                  ShortVersion of the system - if relevant
                  Comments

                  Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

                  NoteThis is a business version Id, not a resource version Id (see discussion)
                  Control0..1
                  Typestring
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  40. DeviceMetric.type.coding:MDCType.code
                  Definition

                  A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

                  ShortSymbol in syntax defined by the system
                  Comments

                  Required for all measurements

                  Control1..1
                  Typecode
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Requirements

                  Need to refer to a particular code in the system.

                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  42. DeviceMetric.type.coding:MDCType.display
                  Definition

                  A representation of the meaning of the code in the system, following the rules of the system.

                  ShortRepresentation defined by the system
                  Control0..1
                  Typestring
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Requirements

                  Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  44. DeviceMetric.type.coding:MDCType.userSelected
                  Definition

                  Indicates that this coding was chosen by a user directly - e.g. off a pick list of available items (codes or displays).

                  ShortIf this coding was chosen directly by the user
                  Comments

                  Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.

                  Control0..1
                  Typeboolean
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Requirements

                  This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.

                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  46. DeviceMetric.type.text
                  Definition

                  A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user.

                  ShortIt is recommended to display at least the reference identifier for the MDC code.
                  Comments

                  Very often the text is the same as a displayName of one of the codings.

                  Control0..1
                  Typestring
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Requirements

                  The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source.

                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  48. DeviceMetric.unit
                  Definition

                  Describes the unit that an observed value determined for this metric will have. For example: Percent, Seconds, etc.

                  ShortUnit of Measure for the Metric
                  Comments

                  When the type of the observation is numeric or compound numeric, the unit could be filled in as well. This should be a UCUM code, but when that is not known, it can be an MDC code. This field can be updated by the gateway when an observation of the corresponding type is generated by the PHD.

                  Control0..1
                  BindingThe codes SHOULD be taken from DeviceMetricAndComponentTypes
                  (preferred to http://hl7.org/fhir/ValueSet/devicemetric-type)

                  Describes the unit of the metric.

                  TypeCodeableConcept
                  Is Modifierfalse
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  50. DeviceMetric.source
                  Definition

                  Describes the link to the Device that this DeviceMetric belongs to and that contains administrative device information such as manufacturer, serial number, etc.

                  ShortDescribes the link to the source Device
                  Control0..1
                  TypeReference(PhdDevice)
                  Is Modifierfalse
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  52. DeviceMetric.parent
                  Definition

                  Describes the link to the Device that this DeviceMetric belongs to and that provide information about the location of this DeviceMetric in the containment structure of the parent Device. An example would be a Device that represents a Channel. This reference can be used by a client application to distinguish DeviceMetrics that have the same type, but should be interpreted based on their containment location.

                  ShortDescribes the link to the parent Device
                  Control0..1
                  TypeReference(Device)
                  Is Modifierfalse
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  54. DeviceMetric.operationalStatus
                  Definition

                  Indicates current operational state of the device. For example: On, Off, Standby, etc.

                  Shorton | off | standby | entered-in-error
                  Comments

                  For a PHD device the operational status is only known when it is communicating. It is recommended to leave this field out.

                  Control0..1
                  BindingThe codes SHALL be taken from DeviceMetricOperationalStatus
                  (required to http://hl7.org/fhir/ValueSet/metric-operational-status|4.0.1)

                  Describes the operational status of the DeviceMetric.

                  Typecode
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  56. DeviceMetric.color
                  Definition

                  Describes the color representation for the metric. This is often used to aid clinicians to track and identify parameter types by color. In practice, consider a Patient Monitor that has ECG/HR and Pleth for example; the parameters are displayed in different characteristic colors, such as HR-blue, BP-green, and PR and SpO2- magenta.

                  Shortblack | red | green | yellow | blue | magenta | cyan | white
                  Control0..1
                  BindingThe codes SHALL be taken from DeviceMetricColor
                  (required to http://hl7.org/fhir/ValueSet/metric-color|4.0.1)

                  Describes the typical color of representation.

                  Typecode
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  58. DeviceMetric.category
                  Definition

                  Indicates the category of the observation generation process. A DeviceMetric can be for example a setting, measurement, or calculation.

                  Shortmeasurement | setting | calculation | unspecified
                  Comments

                  When the category can be derived from the type of the DeviceMetric it can be filled in on creation. Otherwise it can be filled in by updating the DeviceMetric resource when the PHD generates an observation of that type. It can be set to #unspecified until known.

                  Control1..1
                  BindingThe codes SHALL be taken from DeviceMetricCategory
                  (required to http://hl7.org/fhir/ValueSet/metric-category|4.0.1)

                  Describes the category of the metric.

                  Typecode
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  60. DeviceMetric.measurementPeriod
                  Definition

                  Describes the measurement repetition time. This is not necessarily the same as the update period. The measurement repetition time can range from milliseconds up to hours. An example for a measurement repetition time in the range of milliseconds is the sampling rate of an ECG. An example for a measurement repetition time in the range of hours is a NIBP that is triggered automatically every hour. The update period may be different than the measurement repetition time, if the device does not update the published observed value with the same frequency as it was measured.

                  ShortDescribes the measurement repetition time
                  Comments

                  when this information is provided by a GHS device in an Observation Schedule descriptor, it should be filled in here as well.

                  Control0..1
                  TypeTiming
                  Is Modifierfalse
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  62. DeviceMetric.calibration
                  Definition

                  Describes the calibrations that have been performed or that are required to be performed.

                  ShortDescribes the calibrations that have been performed or that are required to be performed
                  Control0..*
                  TypeBackboneElement
                  Is Modifierfalse
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  64. DeviceMetric.calibration.id
                  Definition

                  Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                  ShortUnique id for inter-element referencing
                  Control0..1
                  Typestring
                  Is Modifierfalse
                  XML FormatIn the XML format, this property is represented as an attribute.
                  Summaryfalse
                  66. DeviceMetric.calibration.extension
                  Definition

                  May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                  ShortAdditional content defined by implementations
                  Comments

                  There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                  Control0..*
                  TypeExtension
                  Is Modifierfalse
                  Summaryfalse
                  Alternate Namesextensions, user content
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                  68. DeviceMetric.calibration.modifierExtension
                  Definition

                  May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

                  Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

                  ShortExtensions that cannot be ignored even if unrecognized
                  Comments

                  There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                  Control0..*
                  TypeExtension
                  Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
                  Summarytrue
                  Requirements

                  Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

                  Alternate Namesextensions, user content, modifiers
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                  70. DeviceMetric.calibration.type
                  Definition

                  Describes the type of the calibration method.

                  Shortunspecified | offset | gain | two-point
                  Control0..1
                  BindingThe codes SHALL be taken from DeviceMetricCalibrationType
                  (required to http://hl7.org/fhir/ValueSet/metric-calibration-type|4.0.1)

                  Describes the type of a metric calibration.

                  Typecode
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  72. DeviceMetric.calibration.state
                  Definition

                  Describes the state of the calibration.

                  Shortnot-calibrated | calibration-required | calibrated | unspecified
                  Control0..1
                  BindingThe codes SHALL be taken from DeviceMetricCalibrationState
                  (required to http://hl7.org/fhir/ValueSet/metric-calibration-state|4.0.1)

                  Describes the state of a metric calibration.

                  Typecode
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  74. DeviceMetric.calibration.time
                  Definition

                  Describes the time last calibration has been performed.

                  ShortDescribes the time last calibration has been performed
                  Control0..1
                  Typeinstant
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))