This structure is derived from Observationvitalsignsbase.

Summary

10.1.18.37.2 Complete Summary of the Mandatory Requirements

1. One code in Observation.category which must have
   • a fixed Observation.category.coding.system='http ://loinc.org'
   • a fixed Observation.category.coding.code= '9843-4'
   • The code (or codes) for the measurement obtained in Observation.code. All codes SHALL have a system value
2. Either one Observation.valueQuantity or, if there is no value, one code in Observation.DataAbsentReason
   • Each Observation.valueQuantity must have:
     • One numeric value in Observation.valueQuantity.value
     • a fixed Observation.valueQuantity.system="http://unitsofmeasure.org"
     • a UCUM unit code in Observation.valueQuantity.code = 'cm', or '[in_i]'

Mandatory: 1 element (+4 nested mandatory elements)
Must-Support: 4 elements
Fixed Value: 1 element

Slices

This structure defines the following Slices:

• The element Observation.category is sliced based on the value of pattern:$this

This indicates the differences between this profile and the base Observationvitalsignsbase structure.

Name	Flags	Card.	Type	Description & Constraints
Observation		0..*	Observationvitalsignsbase	FHIR Head Circumference Profile
Slices for category		2..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this
category:HeadCircumCode		1..1	CodeableConcept	Classification of type of observation Required Pattern: At least the following
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://loinc.org
code		1..1	code	Symbol in syntax defined by the system Fixed Value: 9843-4
code		1..1	CodeableConcept	Head Circumference Binding: Vital Signs - Head Circumference (preferred): This identifies the set of LOINC codes that are appropriate for representing head circumference vital sign measurements in Observation.code.
valueQuantity		0..1	Quantity	Vital Sign Value recorded with UCUM (preferred)
value	S	1..1	decimal	Numerical value (with implicit precision)
unit	S	1..1	string	Unit representation
system	S	1..1	uri	System that defines coded unit form Fixed Value: http://unitsofmeasure.org
code	S	1..1	code	Coded responses from the common UCUM units for vital signs value set. Binding: Body Length Units (required): cm | [in_i]
Documentation for this format

This provides the consolidated view (aka snapshot) of the profile after applying the changes in this profile to the base Observationvitalsignsbase structure.

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observationvitalsignsbase	FHIR Head Circumference Profile obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present obs-7: If Observation.component.code is the same as Observation.code, then Observation.value SHALL NOT be present (the Observation.component.value[x] holds the value). obs-8: bodyStructure SHALL only be present if Observation.bodySite is not present vs-2: If there is no component or hasMember element then either a value[x] or a data absent reason must be present.
id	Σ	0..1	id	Logical id of this artifact
meta	Σ	0..1	Meta	Metadata about the resource
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
language		0..1	code	Language of the resource content Binding: All Languages (required): IETF language tag for a human language Additional Bindings Purpose Common Languages Starter Set
text		0..1	Narrative	Text summary of the resource, for human interpretation
contained		0..*	Resource	Contained, inline Resources
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored
identifier	Σ	0..*	Identifier	Business Identifier for observation
instantiates[x]	Σ	0..1	canonical(ObservationDefinition), Reference(ObservationDefinition)	Instantiates FHIR ObservationDefinition
basedOn	Σ	0..*	Reference(CarePlan | DeviceRequest | ImmunizationRecommendation | MedicationRequest | NutritionOrder | ServiceRequest)	Fulfills plan, proposal or order
triggeredBy		0..*	BackboneElement	Triggering observation(s)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
observation	Σ	1..1	Reference(Observation)	Triggering observation
type	Σ	1..1	code	reflex | repeat | re-run Binding: triggered Bytype (required): The type of TriggeredBy Observation.
reason		0..1	string	Reason that the observation was triggered
partOf	Σ	0..*	Reference(MedicationAdministration | MedicationDispense | MedicationStatement | Procedure | Immunization | ImagingStudy | GenomicStudy)	Part of referenced event
status	?!SΣ	1..1	code	registered | preliminary | final | amended | corrected | appended | cancelled | entered-in-error | unknown Binding: Observation Status (required)
Slices for category	S	2..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: Vital Signs Category (preferred): This value set includes the required vital sign interoperability categories.
category:VSCat	S	1..1	CodeableConcept	Classification of type of observation Binding: Observation Category Codes (preferred): Codes for high level observation categories. Required Pattern: At least the following
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
version		0..1	string	Version of the system - if relevant
code		1..1	code	Symbol in syntax defined by the system Fixed Value: vital-signs
display		0..1	string	Representation defined by the system
userSelected		0..1	boolean	If this coding was chosen directly by the user
text		0..1	string	Plain text representation of the concept
category:HeadCircumCode	S	1..1	CodeableConcept	Classification of type of observation Binding: Vital Signs Category (preferred): This value set includes the required vital sign interoperability categories. Required Pattern: At least the following
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
system		1..1	uri	Identity of the terminology system Fixed Value: http://loinc.org
version		0..1	string	Version of the system - if relevant
code		1..1	code	Symbol in syntax defined by the system Fixed Value: 9843-4
display		0..1	string	Representation defined by the system
userSelected		0..1	boolean	If this coding was chosen directly by the user
text		0..1	string	Plain text representation of the concept
code	SΣC	1..1	CodeableConcept	Head Circumference Binding: Vital Signs - Head Circumference (preferred): This identifies the set of LOINC codes that are appropriate for representing head circumference vital sign measurements in Observation.code.
subject	SΣ	1..1	Reference(Patient)	Who and/or what the observation is about
focus	Σ	0..*	Reference(Resource)	What the observation is about, when it is not about the subject of record
encounter	Σ	0..1	Reference(Encounter)	Healthcare event during which this observation is made
effective[x]	SΣC	1..1		Often just a dateTime for Vital Signs vs-1: if Observation.effective[x] is dateTime and has a value then that value shall be precise to the day
effectiveDateTime			dateTime
effectivePeriod			Period
issued	Σ	0..1	instant	Date/Time this version was made available
performer	Σ	0..*	Reference(Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson)	Who is responsible for the observation
Slices for value[x]	SΣC	0..1	Quantity	Vital Signs value are recorded using the Quantity data type. For supporting observations such as Cuff size could use other datatypes such as CodeableConcept. Slice: Unordered, Closed by type:$this
value[x]:valueQuantity	SΣC	0..1	Quantity	Vital Sign Value recorded with UCUM (preferred) Binding: Vital Signs Units (preferred): Commonly encountered UCUM units for recording Vital Signs.
id		0..1	id	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
value	S	1..1	decimal	Numerical value (with implicit precision)
comparator	?!	0..1	code	< | <= | >= | > | ad - how to understand the value Binding: QuantityComparator (required): How the Quantity should be understood and represented.
unit	S	1..1	string	Unit representation
system	SC	1..1	uri	System that defines coded unit form Fixed Value: http://unitsofmeasure.org
code	SC	1..1	code	Coded responses from the common UCUM units for vital signs value set. Binding: Body Length Units (required): cm | [in_i]
dataAbsentReason	SC	0..1	CodeableConcept	Why the result value is missing Binding: Data Absent Reason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
interpretation		0..*	CodeableConcept	High, low, normal, etc Binding: Observation Interpretation Codes (extensible): Codes identifying interpretations of observations.
note		0..*	Annotation	Comments about the observation
bodySite	C	0..1	CodeableConcept	Observed body part Binding: SNOMED CT Body Structures (example): SNOMED CT Body site concepts
bodyStructure	C	0..1	Reference(BodyStructure)	Observed body structure
method		0..1	CodeableConcept	How it was done Binding: Observation Methods (example): Methods for simple observations.
specimen	C	0..1	Reference(Specimen | Group)	Specimen used for this observation obs-9: If Observation.specimen is a reference to Group, the group can only have specimens
device		0..1	Reference(Device | DeviceMetric)	A reference to the device that generates the measurements or the device settings for the device
referenceRange	C	0..*	BackboneElement	Provides guide for interpretation obs-3: Must have at least a low or a high or text
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
low	C	0..1	SimpleQuantity	Low Range, if relevant
high	C	0..1	SimpleQuantity	High Range, if relevant
normalValue		0..1	CodeableConcept	Normal value, if relevant Binding: Observation Reference Range Normal Value Codes (extensible): Codes identifying the normal value of the observation.
type		0..1	CodeableConcept	Reference range qualifier Binding: Observation Reference Range Meaning Codes (preferred): Code for the meaning of a reference range.
appliesTo		0..*	CodeableConcept	Reference range population Binding: Observation Reference Range Applies To Codes (example): Codes identifying the population the reference range applies to.
age		0..1	Range	Applicable age range, if relevant
text	C	0..1	markdown	Text based reference range in an observation
hasMember	Σ	0..*	Reference(QuestionnaireResponse | MolecularSequence | Vital Signs Base Profile)	Used when reporting vital signs panel components
derivedFrom	Σ	0..*	Reference(DocumentReference | ImagingStudy | QuestionnaireResponse | MolecularSequence | Vital Signs Base Profile)	Related resource from which the observation is made
component	SΣC	0..*	BackboneElement	Used when reporting systolic and diastolic blood pressure. vs-3: If there is no a value a data absent reason must be present
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
code	SΣC	1..1	CodeableConcept	Type of component observation (code / type) Binding: Vital Signs Component Measurement (preferred): This identifies the vital sign component measurement.
Slices for value[x]	SΣC	0..1		Vital Sign Value Slice: Unordered, Open by type:$this
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
valueAttachment			Attachment
valueReference			Reference(MolecularSequence)
value[x]:valueQuantity	SΣ	0..1	Quantity	Vital Sign Component Value recorded with UCUM (preferred) Binding: Vital Signs Units (preferred): Commonly encountered UCUM units for recording Vital Signs Components.
dataAbsentReason	SC	0..1	CodeableConcept	Why the component result value is missing Binding: Data Absent Reason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
interpretation		0..*	CodeableConcept	High, low, normal, etc Binding: Observation Interpretation Codes (extensible): Codes identifying interpretations of observations.
referenceRange		0..*	See referenceRange (Observation)	Provides guide for interpretation of component result value
Documentation for this format

<!-- Observationheadcircum -->

<Observation xmlns="http://hl7.org/fhir"
>
  <!-- from Element: extension -->
 <id value="[id]"/><!-- 0..1 Logical id of this artifact -->
 <meta><!-- I 0..1 Meta Metadata about the resource --></meta>
 <implicitRules value="[uri]"/><!-- I 0..1 A set of rules under which this content was created -->
 <language value="[code]"/><!-- I 0..1 Language of the resource content   -->
 <text><!-- I 0..1 Narrative 
     Text summary of the resource, for human interpretation --></text>
 <contained><!-- 0..* Resource Contained, inline Resources --></contained>
 <modifierExtension><!-- I 0..* Extension  Extensions that cannot be ignored  --></modifierExtension>
 <identifier><!-- I 0..* Identifier 
     Business Identifier for observation --></identifier>
 <instantiates[x]><!-- I 0..1 canonical|Reference(ObservationDefinition) 
     Instantiates FHIR ObservationDefinition --></instantiates[x]>
 <basedOn><!-- I 0..* Reference(CarePlan) Fulfills plan, proposal or order --></basedOn>
 <triggeredBy> I 0..* BackboneElement  <!-- I 0..* Triggering observation(s) -->
  <modifierExtension><!-- I 0..* Extension  Extensions that cannot be ignored even if unrecognized  --></modifierExtension>
  <observation><!-- I 1..1 Reference(Observation) 
      Triggering observation --></observation>
  <type value="[code]"/><!-- I 1..1 reflex | repeat | re-run   -->
  <reason value="[string]"/><!-- I 0..1 Reason that the observation was triggered -->
 </triggeredBy>
 <partOf><!-- I 0..* Reference(MedicationAdministration) Part of referenced event --></partOf>
 <status value="[code]"/><!-- I 1..1 registered | preliminary | final | amended | corrected | appended | cancelled | entered-in-error | unknown   -->
 <-- category sliced by pattern:$this  in the specified orderOpen-->
 <category><!-- I 1..1 CodeableConcept Classification of  type of observation   --></category>
 <category><!-- I 1..1 CodeableConcept Classification of  type of observation   --></category>
 <code><!-- I 1..1 CodeableConcept Head Circumference   --></code>
 <subject><!-- I 1..1 Reference(Patient) 
     Who and/or what the observation is about --></subject>
 <focus><!-- I 0..* Reference(Resource) 
     What the observation is about, when it is not about the subject of record --></focus>
 <encounter><!-- I 0..1 Reference(Encounter) 
     Healthcare event during which this observation is made --></encounter>
 <effective[x]><!-- I 1..1 dateTime|Period 
     Often just a dateTime for Vital Signs --></effective[x]>
 <issued value="[instant]"/><!-- I 0..1 Date/Time this version was made available -->
 <performer><!-- I 0..* Reference(Practitioner) 
     Who is responsible for the observation --></performer>
 <-- valueQuantity sliced by type:$this  in the specified orderClosed-->
 <valueQuantity> I 0..1 Quantity  <!-- I 0..1 Vital Sign Value recorded with UCUM (preferred) -->
  <value value="[decimal]"/><!-- I 1..1 Numerical value (with implicit precision) -->
  <comparator value="[code]"/><!-- I 0..1 < | <= | >= | > | ad - how to understand the value   -->
  <unit value="[string]"/><!-- I 1..1 Unit representation -->
  <system value="[uri]"/><!-- I 1..1 System that defines coded unit form -->
  <code value="[code]"/><!-- I 1..1 Coded responses from the common UCUM units for vital signs value set.   -->
 </valueQuantity>
 <dataAbsentReason><!-- I 0..1 CodeableConcept Why the result value is missing   --></dataAbsentReason>
 <interpretation><!-- I 0..* CodeableConcept High, low, normal, etc   --></interpretation>
 <note><!-- I 0..* Annotation Comments about the observation --></note>
 <bodySite><!-- I 0..1 CodeableConcept Observed body part   --></bodySite>
 <bodyStructure><!-- I 0..1 Reference(BodyStructure) Observed body structure --></bodyStructure>
 <method><!-- I 0..1 CodeableConcept How it was done   --></method>
 <specimen><!-- I 0..1 Reference(Specimen) Specimen used for this observation --></specimen>
 <device><!-- I 0..1 Reference(Device) 
     A reference to the device that generates the measurements or the device settings for the device --></device>
 <referenceRange> I 0..* BackboneElement  <!-- I 0..* Provides guide for interpretation -->
  <modifierExtension><!-- I 0..* Extension  Extensions that cannot be ignored even if unrecognized  --></modifierExtension>
  <low><!-- I 0..1 Quantity 
      Low Range, if relevant --></low>
  <high><!-- I 0..1 Quantity 
      High Range, if relevant --></high>
  <normalValue><!-- I 0..1 CodeableConcept Normal value, if relevant   --></normalValue>
  <type><!-- I 0..1 CodeableConcept Reference range qualifier   --></type>
  <appliesTo><!-- I 0..* CodeableConcept Reference range population   --></appliesTo>
  <age><!-- I 0..1 Range 
      Applicable age range, if relevant --></age>
  <text value="[markdown]"/><!-- I 0..1 Text based reference range in an observation -->
 </referenceRange>
 <hasMember><!-- I 0..* Reference(QuestionnaireResponse) 
     Used when reporting vital signs panel components --></hasMember>
 <derivedFrom><!-- I 0..* Reference(DocumentReference) 
     Related resource from which the observation is made --></derivedFrom>
 <component> I 0..* BackboneElement  <!-- I 0..* Used when reporting systolic and diastolic blood pressure. -->
  <modifierExtension><!-- I 0..* Extension  Extensions that cannot be ignored even if unrecognized  --></modifierExtension>
  <code><!-- I 1..1 CodeableConcept Type of component observation (code / type)   --></code>
  <-- value[x] sliced by type:$this  in the specified orderOpen-->
  <valueQuantity><!-- I 0..1 Quantity Vital Sign Component Value recorded with UCUM (preferred)   --></valueQuantity>
  <dataAbsentReason><!-- I 0..1 CodeableConcept Why the component result value is missing   --></dataAbsentReason>
  <interpretation><!-- I 0..* CodeableConcept High, low, normal, etc   --></interpretation>
  <referenceRange><!-- See http://hl7.org/fhir/StructureDefinition/Observation#Observation.referenceRange  Provides guide for interpretation of component result value --></referenceRange>
 </component>
</Observation>

{ // Observationheadcircum
  // from Element: extension
    "meta" : { Meta }, // IMetadata about the resource
    "implicitRules" : "<uri>", // IA set of rules under which this content was created
    "language" : "<code>", // ILanguage of the resource content
    "text" : { Narrative }, // IText summary of the resource, for human interpretation
    "contained" : [{ Resource }], //Contained, inline Resources
    "modifierExtension" : [{ Extension }], // IExtensions that cannot be ignored
    "identifier" : [{ Identifier }], // IBusiness Identifier for observation
  // value[x]: Instantiates FHIR ObservationDefinition. One of these 2:
    "instantiatesCanonical" : "<canonical>", // IInstantiates FHIR ObservationDefinition
    "instantiatesReference" : { Reference(ObservationDefinition) }, // IInstantiates FHIR ObservationDefinition
    "basedOn" : [{ Reference(CarePlan) }], // IFulfills plan, proposal or order
    "triggeredBy" : [{ BackboneElement }], // ITriggering observation(s)
    "partOf" : [{ Reference(MedicationAdministration) }], // IPart of referenced event
    "status" : "<code>", // I R! registered | preliminary | final | amended | corrected | appended | cancelled | entered-in-error | unknown
    "category" : [ //  sliced by pattern:$this  in the specified order, Open 
      { // Classification of  type of observation // I R! 
        // from Element: extension
      },
      { // Classification of  type of observation // I R! 
        // from Element: extension
      }
    ],
    "code" : { CodeableConcept }, // I R! Head Circumference
    "subject" : { Reference(Patient) }, // I R! Who and/or what the observation is about
    "focus" : [{ Reference(Resource) }], // IWhat the observation is about, when it is not about the subject of record
    "encounter" : { Reference(Encounter) }, // IHealthcare event during which this observation is made
  // value[x]: Often just a dateTime for Vital Signs. One of these 2:
    "effectiveDateTime" : "<dateTime>", // I R! Often just a dateTime for Vital Signs
    "effectivePeriod" : { Period }, // I R! Often just a dateTime for Vital Signs
    "issued" : "<instant>", // IDate/Time this version was made available
    "performer" : [{ Reference(Practitioner) }], // IWho is responsible for the observation
    "valueQuantity" : [ //  sliced by type:$this  in the specified order, Closed 
      { // Vital Sign Value recorded with UCUM (preferred) // I
        // from Element: extension
        "extension" : [ //  sliced by value:url  in the specified order, Open ]
        "value" : <decimal>, // I R! Numerical value (with implicit precision)
        "comparator" : "<code>", // I< | <= | >= | > | ad - how to understand the value
        "unit" : "<string>", // I R! Unit representation
        "system" : "http://unitsofmeasure.org", // I R! 
        "code" : "<code>" // I R! Coded responses from the common UCUM units for vital signs value set.
      }
    ],
    "dataAbsentReason" : { CodeableConcept }, // IWhy the result value is missing
    "interpretation" : [{ CodeableConcept }], // IHigh, low, normal, etc
    "note" : [{ Annotation }], // IComments about the observation
    "bodySite" : { CodeableConcept }, // IObserved body part
    "bodyStructure" : { Reference(BodyStructure) }, // IObserved body structure
    "method" : { CodeableConcept }, // IHow it was done
    "specimen" : { Reference(Specimen) }, // ISpecimen used for this observation
    "device" : { Reference(Device) }, // IA reference to the device that generates the measurements or the device settings for the device
    "referenceRange" : [{ BackboneElement }], // IProvides guide for interpretation
    "hasMember" : [{ Reference(QuestionnaireResponse) }], // IUsed when reporting vital signs panel components
    "derivedFrom" : [{ Reference(DocumentReference) }], // IRelated resource from which the observation is made
    "component" : [{ BackboneElement }], // IUsed when reporting systolic and diastolic blood pressure.
  }

Summary

10.1.18.37.3 Complete Summary of the Mandatory Requirements

1. One code in Observation.category which must have
   • a fixed Observation.category.coding.system='http ://loinc.org'
   • a fixed Observation.category.coding.code= '9843-4'
   • The code (or codes) for the measurement obtained in Observation.code. All codes SHALL have a system value
2. Either one Observation.valueQuantity or, if there is no value, one code in Observation.DataAbsentReason
   • Each Observation.valueQuantity must have:
     • One numeric value in Observation.valueQuantity.value
     • a fixed Observation.valueQuantity.system="http://unitsofmeasure.org"
     • a UCUM unit code in Observation.valueQuantity.code = 'cm', or '[in_i]'

Mandatory: 1 element (+4 nested mandatory elements)
Must-Support: 4 elements
Fixed Value: 1 element

Slices

This structure defines the following Slices:

• The element Observation.category is sliced based on the value of pattern:$this

This provides the consolidated view (aka snapshot) of the profile after applying the changes in this profile to the base Observationvitalsignsbase structure.

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observationvitalsignsbase	FHIR Head Circumference Profile obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present obs-7: If Observation.component.code is the same as Observation.code, then Observation.value SHALL NOT be present (the Observation.component.value[x] holds the value). obs-8: bodyStructure SHALL only be present if Observation.bodySite is not present vs-2: If there is no component or hasMember element then either a value[x] or a data absent reason must be present.
id	Σ	0..1	id	Logical id of this artifact
meta	Σ	0..1	Meta	Metadata about the resource
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
language		0..1	code	Language of the resource content Binding: All Languages (required): IETF language tag for a human language Additional Bindings Purpose Common Languages Starter Set
text		0..1	Narrative	Text summary of the resource, for human interpretation
contained		0..*	Resource	Contained, inline Resources
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored
identifier	Σ	0..*	Identifier	Business Identifier for observation
instantiates[x]	Σ	0..1	canonical(ObservationDefinition), Reference(ObservationDefinition)	Instantiates FHIR ObservationDefinition
basedOn	Σ	0..*	Reference(CarePlan | DeviceRequest | ImmunizationRecommendation | MedicationRequest | NutritionOrder | ServiceRequest)	Fulfills plan, proposal or order
triggeredBy		0..*	BackboneElement	Triggering observation(s)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
observation	Σ	1..1	Reference(Observation)	Triggering observation
type	Σ	1..1	code	reflex | repeat | re-run Binding: triggered Bytype (required): The type of TriggeredBy Observation.
reason		0..1	string	Reason that the observation was triggered
partOf	Σ	0..*	Reference(MedicationAdministration | MedicationDispense | MedicationStatement | Procedure | Immunization | ImagingStudy | GenomicStudy)	Part of referenced event
status	?!SΣ	1..1	code	registered | preliminary | final | amended | corrected | appended | cancelled | entered-in-error | unknown Binding: Observation Status (required)
Slices for category	S	2..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: Vital Signs Category (preferred): This value set includes the required vital sign interoperability categories.
category:VSCat	S	1..1	CodeableConcept	Classification of type of observation Binding: Observation Category Codes (preferred): Codes for high level observation categories. Required Pattern: At least the following
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
version		0..1	string	Version of the system - if relevant
code		1..1	code	Symbol in syntax defined by the system Fixed Value: vital-signs
display		0..1	string	Representation defined by the system
userSelected		0..1	boolean	If this coding was chosen directly by the user
text		0..1	string	Plain text representation of the concept
category:HeadCircumCode	S	1..1	CodeableConcept	Classification of type of observation Binding: Vital Signs Category (preferred): This value set includes the required vital sign interoperability categories. Required Pattern: At least the following
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
system		1..1	uri	Identity of the terminology system Fixed Value: http://loinc.org
version		0..1	string	Version of the system - if relevant
code		1..1	code	Symbol in syntax defined by the system Fixed Value: 9843-4
display		0..1	string	Representation defined by the system
userSelected		0..1	boolean	If this coding was chosen directly by the user
text		0..1	string	Plain text representation of the concept
code	SΣC	1..1	CodeableConcept	Head Circumference Binding: Vital Signs - Head Circumference (preferred): This identifies the set of LOINC codes that are appropriate for representing head circumference vital sign measurements in Observation.code.
subject	SΣ	1..1	Reference(Patient)	Who and/or what the observation is about
focus	Σ	0..*	Reference(Resource)	What the observation is about, when it is not about the subject of record
encounter	Σ	0..1	Reference(Encounter)	Healthcare event during which this observation is made
effective[x]	SΣC	1..1		Often just a dateTime for Vital Signs vs-1: if Observation.effective[x] is dateTime and has a value then that value shall be precise to the day
effectiveDateTime			dateTime
effectivePeriod			Period
issued	Σ	0..1	instant	Date/Time this version was made available
performer	Σ	0..*	Reference(Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson)	Who is responsible for the observation
Slices for value[x]	SΣC	0..1	Quantity	Vital Signs value are recorded using the Quantity data type. For supporting observations such as Cuff size could use other datatypes such as CodeableConcept. Slice: Unordered, Closed by type:$this
value[x]:valueQuantity	SΣC	0..1	Quantity	Vital Sign Value recorded with UCUM (preferred) Binding: Vital Signs Units (preferred): Commonly encountered UCUM units for recording Vital Signs.
id		0..1	id	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
value	S	1..1	decimal	Numerical value (with implicit precision)
comparator	?!	0..1	code	< | <= | >= | > | ad - how to understand the value Binding: QuantityComparator (required): How the Quantity should be understood and represented.
unit	S	1..1	string	Unit representation
system	SC	1..1	uri	System that defines coded unit form Fixed Value: http://unitsofmeasure.org
code	SC	1..1	code	Coded responses from the common UCUM units for vital signs value set. Binding: Body Length Units (required): cm | [in_i]
dataAbsentReason	SC	0..1	CodeableConcept	Why the result value is missing Binding: Data Absent Reason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
interpretation		0..*	CodeableConcept	High, low, normal, etc Binding: Observation Interpretation Codes (extensible): Codes identifying interpretations of observations.
note		0..*	Annotation	Comments about the observation
bodySite	C	0..1	CodeableConcept	Observed body part Binding: SNOMED CT Body Structures (example): SNOMED CT Body site concepts
bodyStructure	C	0..1	Reference(BodyStructure)	Observed body structure
method		0..1	CodeableConcept	How it was done Binding: Observation Methods (example): Methods for simple observations.
specimen	C	0..1	Reference(Specimen | Group)	Specimen used for this observation obs-9: If Observation.specimen is a reference to Group, the group can only have specimens
device		0..1	Reference(Device | DeviceMetric)	A reference to the device that generates the measurements or the device settings for the device
referenceRange	C	0..*	BackboneElement	Provides guide for interpretation obs-3: Must have at least a low or a high or text
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
low	C	0..1	SimpleQuantity	Low Range, if relevant
high	C	0..1	SimpleQuantity	High Range, if relevant
normalValue		0..1	CodeableConcept	Normal value, if relevant Binding: Observation Reference Range Normal Value Codes (extensible): Codes identifying the normal value of the observation.
type		0..1	CodeableConcept	Reference range qualifier Binding: Observation Reference Range Meaning Codes (preferred): Code for the meaning of a reference range.
appliesTo		0..*	CodeableConcept	Reference range population Binding: Observation Reference Range Applies To Codes (example): Codes identifying the population the reference range applies to.
age		0..1	Range	Applicable age range, if relevant
text	C	0..1	markdown	Text based reference range in an observation
hasMember	Σ	0..*	Reference(QuestionnaireResponse | MolecularSequence | Vital Signs Base Profile)	Used when reporting vital signs panel components
derivedFrom	Σ	0..*	Reference(DocumentReference | ImagingStudy | QuestionnaireResponse | MolecularSequence | Vital Signs Base Profile)	Related resource from which the observation is made
component	SΣC	0..*	BackboneElement	Used when reporting systolic and diastolic blood pressure. vs-3: If there is no a value a data absent reason must be present
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
code	SΣC	1..1	CodeableConcept	Type of component observation (code / type) Binding: Vital Signs Component Measurement (preferred): This identifies the vital sign component measurement.
Slices for value[x]	SΣC	0..1		Vital Sign Value Slice: Unordered, Open by type:$this
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
valueAttachment			Attachment
valueReference			Reference(MolecularSequence)
value[x]:valueQuantity	SΣ	0..1	Quantity	Vital Sign Component Value recorded with UCUM (preferred) Binding: Vital Signs Units (preferred): Commonly encountered UCUM units for recording Vital Signs Components.
dataAbsentReason	SC	0..1	CodeableConcept	Why the component result value is missing Binding: Data Absent Reason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
interpretation		0..*	CodeableConcept	High, low, normal, etc Binding: Observation Interpretation Codes (extensible): Codes identifying interpretations of observations.
referenceRange		0..*	See referenceRange (Observation)	Provides guide for interpretation of component result value
Documentation for this format

<!-- Observationheadcircum -->

<Observation xmlns="http://hl7.org/fhir"
>
  <!-- from Element: extension -->
 <id value="[id]"/><!-- 0..1 Logical id of this artifact -->
 <meta><!-- I 0..1 Meta Metadata about the resource --></meta>
 <implicitRules value="[uri]"/><!-- I 0..1 A set of rules under which this content was created -->
 <language value="[code]"/><!-- I 0..1 Language of the resource content   -->
 <text><!-- I 0..1 Narrative 
     Text summary of the resource, for human interpretation --></text>
 <contained><!-- 0..* Resource Contained, inline Resources --></contained>
 <modifierExtension><!-- I 0..* Extension  Extensions that cannot be ignored  --></modifierExtension>
 <identifier><!-- I 0..* Identifier 
     Business Identifier for observation --></identifier>
 <instantiates[x]><!-- I 0..1 canonical|Reference(ObservationDefinition) 
     Instantiates FHIR ObservationDefinition --></instantiates[x]>
 <basedOn><!-- I 0..* Reference(CarePlan) Fulfills plan, proposal or order --></basedOn>
 <triggeredBy> I 0..* BackboneElement  <!-- I 0..* Triggering observation(s) -->
  <modifierExtension><!-- I 0..* Extension  Extensions that cannot be ignored even if unrecognized  --></modifierExtension>
  <observation><!-- I 1..1 Reference(Observation) 
      Triggering observation --></observation>
  <type value="[code]"/><!-- I 1..1 reflex | repeat | re-run   -->
  <reason value="[string]"/><!-- I 0..1 Reason that the observation was triggered -->
 </triggeredBy>
 <partOf><!-- I 0..* Reference(MedicationAdministration) Part of referenced event --></partOf>
 <status value="[code]"/><!-- I 1..1 registered | preliminary | final | amended | corrected | appended | cancelled | entered-in-error | unknown   -->
 <-- category sliced by pattern:$this  in the specified orderOpen-->
 <category><!-- I 1..1 CodeableConcept Classification of  type of observation   --></category>
 <category><!-- I 1..1 CodeableConcept Classification of  type of observation   --></category>
 <code><!-- I 1..1 CodeableConcept Head Circumference   --></code>
 <subject><!-- I 1..1 Reference(Patient) 
     Who and/or what the observation is about --></subject>
 <focus><!-- I 0..* Reference(Resource) 
     What the observation is about, when it is not about the subject of record --></focus>
 <encounter><!-- I 0..1 Reference(Encounter) 
     Healthcare event during which this observation is made --></encounter>
 <effective[x]><!-- I 1..1 dateTime|Period 
     Often just a dateTime for Vital Signs --></effective[x]>
 <issued value="[instant]"/><!-- I 0..1 Date/Time this version was made available -->
 <performer><!-- I 0..* Reference(Practitioner) 
     Who is responsible for the observation --></performer>
 <-- valueQuantity sliced by type:$this  in the specified orderClosed-->
 <valueQuantity> I 0..1 Quantity  <!-- I 0..1 Vital Sign Value recorded with UCUM (preferred) -->
  <value value="[decimal]"/><!-- I 1..1 Numerical value (with implicit precision) -->
  <comparator value="[code]"/><!-- I 0..1 < | <= | >= | > | ad - how to understand the value   -->
  <unit value="[string]"/><!-- I 1..1 Unit representation -->
  <system value="[uri]"/><!-- I 1..1 System that defines coded unit form -->
  <code value="[code]"/><!-- I 1..1 Coded responses from the common UCUM units for vital signs value set.   -->
 </valueQuantity>
 <dataAbsentReason><!-- I 0..1 CodeableConcept Why the result value is missing   --></dataAbsentReason>
 <interpretation><!-- I 0..* CodeableConcept High, low, normal, etc   --></interpretation>
 <note><!-- I 0..* Annotation Comments about the observation --></note>
 <bodySite><!-- I 0..1 CodeableConcept Observed body part   --></bodySite>
 <bodyStructure><!-- I 0..1 Reference(BodyStructure) Observed body structure --></bodyStructure>
 <method><!-- I 0..1 CodeableConcept How it was done   --></method>
 <specimen><!-- I 0..1 Reference(Specimen) Specimen used for this observation --></specimen>
 <device><!-- I 0..1 Reference(Device) 
     A reference to the device that generates the measurements or the device settings for the device --></device>
 <referenceRange> I 0..* BackboneElement  <!-- I 0..* Provides guide for interpretation -->
  <modifierExtension><!-- I 0..* Extension  Extensions that cannot be ignored even if unrecognized  --></modifierExtension>
  <low><!-- I 0..1 Quantity 
      Low Range, if relevant --></low>
  <high><!-- I 0..1 Quantity 
      High Range, if relevant --></high>
  <normalValue><!-- I 0..1 CodeableConcept Normal value, if relevant   --></normalValue>
  <type><!-- I 0..1 CodeableConcept Reference range qualifier   --></type>
  <appliesTo><!-- I 0..* CodeableConcept Reference range population   --></appliesTo>
  <age><!-- I 0..1 Range 
      Applicable age range, if relevant --></age>
  <text value="[markdown]"/><!-- I 0..1 Text based reference range in an observation -->
 </referenceRange>
 <hasMember><!-- I 0..* Reference(QuestionnaireResponse) 
     Used when reporting vital signs panel components --></hasMember>
 <derivedFrom><!-- I 0..* Reference(DocumentReference) 
     Related resource from which the observation is made --></derivedFrom>
 <component> I 0..* BackboneElement  <!-- I 0..* Used when reporting systolic and diastolic blood pressure. -->
  <modifierExtension><!-- I 0..* Extension  Extensions that cannot be ignored even if unrecognized  --></modifierExtension>
  <code><!-- I 1..1 CodeableConcept Type of component observation (code / type)   --></code>
  <-- value[x] sliced by type:$this  in the specified orderOpen-->
  <valueQuantity><!-- I 0..1 Quantity Vital Sign Component Value recorded with UCUM (preferred)   --></valueQuantity>
  <dataAbsentReason><!-- I 0..1 CodeableConcept Why the component result value is missing   --></dataAbsentReason>
  <interpretation><!-- I 0..* CodeableConcept High, low, normal, etc   --></interpretation>
  <referenceRange><!-- See http://hl7.org/fhir/StructureDefinition/Observation#Observation.referenceRange  Provides guide for interpretation of component result value --></referenceRange>
 </component>
</Observation>

{ // Observationheadcircum
  // from Element: extension
    "meta" : { Meta }, // IMetadata about the resource
    "implicitRules" : "<uri>", // IA set of rules under which this content was created
    "language" : "<code>", // ILanguage of the resource content
    "text" : { Narrative }, // IText summary of the resource, for human interpretation
    "contained" : [{ Resource }], //Contained, inline Resources
    "modifierExtension" : [{ Extension }], // IExtensions that cannot be ignored
    "identifier" : [{ Identifier }], // IBusiness Identifier for observation
  // value[x]: Instantiates FHIR ObservationDefinition. One of these 2:
    "instantiatesCanonical" : "<canonical>", // IInstantiates FHIR ObservationDefinition
    "instantiatesReference" : { Reference(ObservationDefinition) }, // IInstantiates FHIR ObservationDefinition
    "basedOn" : [{ Reference(CarePlan) }], // IFulfills plan, proposal or order
    "triggeredBy" : [{ BackboneElement }], // ITriggering observation(s)
    "partOf" : [{ Reference(MedicationAdministration) }], // IPart of referenced event
    "status" : "<code>", // I R! registered | preliminary | final | amended | corrected | appended | cancelled | entered-in-error | unknown
    "category" : [ //  sliced by pattern:$this  in the specified order, Open 
      { // Classification of  type of observation // I R! 
        // from Element: extension
      },
      { // Classification of  type of observation // I R! 
        // from Element: extension
      }
    ],
    "code" : { CodeableConcept }, // I R! Head Circumference
    "subject" : { Reference(Patient) }, // I R! Who and/or what the observation is about
    "focus" : [{ Reference(Resource) }], // IWhat the observation is about, when it is not about the subject of record
    "encounter" : { Reference(Encounter) }, // IHealthcare event during which this observation is made
  // value[x]: Often just a dateTime for Vital Signs. One of these 2:
    "effectiveDateTime" : "<dateTime>", // I R! Often just a dateTime for Vital Signs
    "effectivePeriod" : { Period }, // I R! Often just a dateTime for Vital Signs
    "issued" : "<instant>", // IDate/Time this version was made available
    "performer" : [{ Reference(Practitioner) }], // IWho is responsible for the observation
    "valueQuantity" : [ //  sliced by type:$this  in the specified order, Closed 
      { // Vital Sign Value recorded with UCUM (preferred) // I
        // from Element: extension
        "extension" : [ //  sliced by value:url  in the specified order, Open ]
        "value" : <decimal>, // I R! Numerical value (with implicit precision)
        "comparator" : "<code>", // I< | <= | >= | > | ad - how to understand the value
        "unit" : "<string>", // I R! Unit representation
        "system" : "http://unitsofmeasure.org", // I R! 
        "code" : "<code>" // I R! Coded responses from the common UCUM units for vital signs value set.
      }
    ],
    "dataAbsentReason" : { CodeableConcept }, // IWhy the result value is missing
    "interpretation" : [{ CodeableConcept }], // IHigh, low, normal, etc
    "note" : [{ Annotation }], // IComments about the observation
    "bodySite" : { CodeableConcept }, // IObserved body part
    "bodyStructure" : { Reference(BodyStructure) }, // IObserved body structure
    "method" : { CodeableConcept }, // IHow it was done
    "specimen" : { Reference(Specimen) }, // ISpecimen used for this observation
    "device" : { Reference(Device) }, // IA reference to the device that generates the measurements or the device settings for the device
    "referenceRange" : [{ BackboneElement }], // IProvides guide for interpretation
    "hasMember" : [{ Reference(QuestionnaireResponse) }], // IUsed when reporting vital signs panel components
    "derivedFrom" : [{ Reference(DocumentReference) }], // IRelated resource from which the observation is made
    "component" : [{ BackboneElement }], // IUsed when reporting systolic and diastolic blood pressure.
  }