The PhdNumericObservation reports PHD measurements that contain one of either a Basic-Nu-Observed-Value, Simple-Nu_observed-Value, or Nu_observed-Value attribute.

Used for non-compound numeric observations from Personal Health Devices.

The decoded Mder FLOAT or SFLOAT value from a PHD measurement containing either a Basic-Nu-Observed-Value Simple-Nu-Observed-Value or Nu_observed-Value attribute.

The implicit precision in the value shall be honored. The Mder encoding used in the above attributes provides this precision. The translating software shall honor that precision when generating this value. This element shall be present unless there is an error reported in the Measurement-Status attribute or the Nu-Observed-Value.status field or the Mder encoding represents one of the special values. In that case there is a dataAbsentReason element and the valueQuantity element is not present. Note that not all measurement status values are errors resulting in no measurement being reported here; for example the preliminary or verified status.

The UCUM code needs to be translated from the 11073-10101 code from the device. This translation means that the reporting of units is not future proof.

Provides a reason why the expected value in the element Observation.valueQuantity is missing. This could be a 'not-a-number', 'positive-infinity', 'negative-infinity' or an error condition indicated by the Measurement-Status attribute or the status field from a Nu-Observed-Value attribute.

The current values in the http://terminology.hl7.org/CodeSystem/data-absent-reason system do not provide a code that matches the special values 'not at this resolution' and 'reserved'. In those cases one uses the generic 'error' code. If both a special value and a Measurement-Status indicating invalid, not unavailable, or msmt ongoing are received, the Measurement-Status mapping takes precedence.

This component shall be present if the Accuracy attribute is present.

The code for the Accuracy attribute is 67914

Should include the reference identifier for the Accuracy attribute MDC_ATTR_NU_ACCUR_MSMT

This is the value of the accuracy attribute. The value is Mder FLOAT encoded and shall be expressed to the precision indicated by the Mder FLOAT.

The unit code shall use the UCUM system

The units for the Accuracy are given by the units of the measurement so this entry shall have the same code as in Observation.valueQuantity.code

This component gives one of the settings reported in the Alert-Op-State attribute. This attribute is used only by the Pulse Oximeter specialization. The Alert-Op-State attribute is used in conjunction with the Current-Limits and Measurement-Status attributes. The Current-Limits defines upper and lower limit thresholds for a reported measurement value. When the reported measurement value goes below or above these limits, a bit is set in the Measurement-Status attribute is set if the Alert-Op-State attribute indicates that the alert is active for the given threshold. Since it is considered important that if a Current-Limits attribute is present an alert shall be sent went the thresholds are crossed, the Alert-Op-State Bits are only set when the alert is, for some reason, turned OFF for a given threshold. There shall be one such alertOpStateComponent entry for every bit set in the Alert-Op-State attribute. There may be an entry for the defined cleared components as well.

Recall that when creating the code for this entry that the code uses the MDER-Bit setting to be reported along with the Alert-Op-State attribute's MDC code. MDER-Bit 0 is the most significant bit of the attribute value. Since the Alert-Op-State attribute is a BITS-16 value, MDER-Bit 0 would have value 0x8000 and MDER-Bit 1 would have value 0x4000. Only bits 0, 1, and 2 are defined for this attribute. This component indicates if a given alert condition monitoring is turned off.

Normally alternative coding systems are allowed but in this case the value is intimately tied to the code. The code represents the feature indicated by a bit setting in the attribute value. which is either cleared (0) or set (1). Thus the value for this entry is itself a binary 'Y' or 'N' code from http://terminology.hl7.org/CodeSystem/v2-0203

This code, which is an alpha-numeric string, is generated by the attribute MDC code, which is 68746 for the Alert-Op-State, followed by a dot (.) followed by the MDER-bit that was set. Given that only three bits are defined in the Pulse Ox specialization that uses this attribute, the code will be one of 68746.0, 68746.1, or 68746.2

Note that this code is an alpha-numeric string and not a decimal number. Think of it like a very-limited OID.

This coding system contains only two entries, 'Y' (bit set) and 'N' (bit cleared)

If the MDER-Bit is set, the code value is 'Y' otherwise it is 'N'. These are 'state' bits thus both the set and cleared states are reported.

Recall that when the value is 'Y' the alarm or alert is turned off

The Current-Limits attribute gives upper and lower threshold values for the triggering of an alert for the measured value being reported in this Observation resource. This attribute is currently used only in the Pulse Oximeter specialization. If the alerting is not turned off, a Measurement-Status attribute bit is set when either threshold is crossed. The Current-Limits attribute value shall be reported if it is present in the measurement.

The value is expressed as a range. The lower and upper values of the range represent the thresholds.

Allows the downstream signaling of an alert and/or warning situation.

Indicates the MDC coding system

The code is that of the Current-Limits attribute

Shall be the code of the Current-Limits attribute.

Should include the reference id for the Current-Limits attribute which is MDC_ATTR_LIMIT_CURR

This value is given by Current-Limits.lower as an MDER-FLOAT and shall be expressed in the precision indicated by the MDER-FLOAT construct.

This gives the lower threshold. If the measurement falls below this value, the Measurement-Status attribute is sent with a bit stating the alert is present (if the alerts are not turned off for the lower limits).

Indicates the UCUM coding system.

This code (which is the code for the units) shall be the same as Observation.valueQuantity.code

The MDC units are translated to UCUM.

The high limit shall be present

This value is given by Current-Limits.upper as an MDER-FLOAT and shall be expressed in the precision indicated by the MDER-FLOAT construct.

This gives the upper threshold. If the measurement goes above this value, the Measurement-Status attribute is sent with a bit stating the alert is present (if the alerts are not turned off for the upper limits).

Indicates the MDC coding system.

This code (which is the code for the units) shall be the same as Observation.valueQuantity.code

The MDC units are translated to UCUM.

This component reports the values in the Alert-Op-Text-String attribute.

This attribute consists of human readable strings giving further information about the upper and lower limits of the Alerts

The MDC code for the Alert-Op-Text-String attribute

The reference identifier for the attribute should be included. The Alert-Op-Text-String attribute ref id is MDC_ATTR_AL_OP_TEXT_STRING

This is the value of the lower and upper text strings presented in an application specific manner.

The Measurement-Confidence-95 attribute defines the lower and upper bounds for a range within which the manufacture is 95% confident that the actual value resides. The unit for the lower bound and upper bound is the same as the measurement.

Indicates the MDC coding system

The code is that of the Current-Limits attribute

Shall be the code of the Current-Limits attribute.

Should include the reference id for the Current-Limits attribute which is MDC_ATTR_MSMT_CONFIDENCE_95

Thsi value is given by Measurement-Confidence-95.lower-bound as an MDER-FLOAT and shall be expressed in the precision indicated by the MDER-FLOAT construct.

This gives the lower bound of the range for which the manufacturer is 95% confident that the measurement reported lies in.

Indicates the UCUM coding system.

This code (which is the code for the units) shall be the same as Observation.valueQuantity.code

The MDC units are translated to UCUM.

The high limit shall be present

This value is given by Measurement-Confidence-95.upper-bound as an MDER-FLOAT and shall be expressed in the precision indicated by the MDER-FLOAT construct.

This gives the upper bound of the range for which the manufacturer is 95% confident that the measurement reported lies in.

Indicates the UCUM coding system.

This code (which is the code for the units) shall be the same as Observation.valueQuantity.code

The MDC units are translated to UCUM.

This component reports the values in the Threshold-Notification-Text-String attribute. This attribute is a human readable string describing the threshold met condition.

This attribute consists of human readable strings giving further information threshold notification(s)

The MDC code for the Threshold-Notification-Text-String attribute

The reference identifier for the attribute should be included. The Threshold-Notification-Text-String attribute ref id is MDC_ATTR_THRES_NOTIF_TEXT_STRING

This is the value of the text string.

The PhdNumericObservation reports PHD measurements that contain one of either a Basic-Nu-Observed-Value, Simple-Nu_observed-Value, or Nu_observed-Value attribute.

Used for non-compound numeric observations from Personal Health Devices.

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.

Security labels applied to this resource. These tags connect specific resources to the overall security policy and infrastructure.

The security labels can be updated without changing the stated version of the resource. The list of security labels is a set. Uniqueness is based the system/code, and version and display are ignored.

Security labels applied to this resource. These tags connect specific resources to the overall security policy and infrastructure.

The security labels can be updated without changing the stated version of the resource. The list of security labels is a set. Uniqueness is based the system/code, and version and display are ignored.

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

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.

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

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).

Need to refer to a particular code in the system.

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.

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.

To be used when the actual gateway used at the time of the observation, and the referenced device is also specified. The gateway device may be acting as a communication/data collector, translator or controller; This extension is useful when there is more than one gateway device, for example, where there are apps on a phone and each are a device, and more than one app is used to pass on the data to a FHIR Server. In that case you need to be able to say from the observation which specific app was used to act as gateway. Note that the Provenance/AuditEvent resources can represent the same information.

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).

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.

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.

A unique identifier assigned to this observation.

Allows observations to be distinguished and referenced.

An identifier created from a combination of the measurement parameters like sensor time stamp, type code, unit code, patient and device identifiers, and selected elements of any component elements.

This value is used in the conditional create to prevent data duplication. PHDs will often re-send already sent data for a variety of reasons. This element is required unless the metric measurement contains no time stamp or is a measurement containing a time stamp that is real time. By real time the time stamp reported by the PHD must be later than the current time reported by the PHD before any measurements are received. There might be other means to ascertain whether the data is real time. Temporarily stored data from IEEE 11073-10206 compliant devices, which are required to be deleted the data after sending, can be considered real time. An example of this are temporarily stored observation from a device implementing the Bluetooth SIG GHS profile or implementing another Bluetooth SIG medical sensor device profile.

Allows observations to be distinguished in a selective enough manner to prevent resource duplication.

The purpose of this identifier.

Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.

A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.

This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.

Allows users to make use of identifiers when the identifier system is not known.

Establishes the namespace for the value - that is, a URL that describes a set values that are unique.

Identifier.system is always case sensitive.

There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.

The portion of the identifier typically relevant to the user and which is unique within the context of the system.

If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe.

The status of the result value. Either 'final' or 'preliminary'

The value shall be set to 'final' unless a Measurement-Status attribute or Nu-Observed-Value attribute status field indicates that the measurement is preliminary. In that case this field shall be set to 'preliminary'

Codes providing the status of an observation.

Need to track the status of individual results. Some results are finalized before the whole report is finalized.

A code that classifies the general type of observation being made.

In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

Codes for high level observation categories.

Used for filtering what observations are retrieved and displayed.

A code that classifies the general type of observation being made.

The category enables identifying observations generated by PHDs.

Codes for high level observation categories.

Used for filtering what observations are retrieved and displayed.

A reference to a code defined by a terminology system.

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.

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

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

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.

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

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).

Need to refer to a particular code in the system.

A code that classifies the general type of observation being made.

In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

Codes for high level observation categories.

Used for filtering what observations are retrieved and displayed.

A reference to a code defined by a terminology system.

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.

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

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

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.

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

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).

Need to refer to a particular code in the system.

Describes what was observed. Sometimes this is called the observation "name".

All code-value and, if present, component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

Codes identifying names of simple observations.

Knowing what kind of observation is being made is essential to understanding the observation.

A reference to a code defined by a terminology system.

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.

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

This MDC code expresses what the measurement is.

The value for the code can be obtained from the IEEE 11073-10206 Observation.type attribute.

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

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

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.

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

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).

Required for all measurements

Need to refer to a particular code in the system.

This LOINC code expresses what the measurement is

If the observation is one of the FHIR-defined vital signs observation, the equivalent LOINC code for that vital sign as specified by FHIR appears here.

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

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

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.

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

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).

Required if the measurement is a vital sign

Need to refer to a particular code in the system.

The patient, or group of patients, location, or device this observation is about and into whose record the observation is placed. If the actual focus of the observation is different from the subject (or a sample of, part, or region of the subject), the focus element or the code itself specifies the actual focus of the observation.

One would expect this element to be a cardinality of 1..1. The only circumstance in which the subject can be missing is when the observation is made by a device that does not know the patient. In this case, the observation SHALL be matched to a patient through some context/channel matching technique, and at this point, the observation should be updated.

Observations have no value if you don't know who or what they're about.

A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources.

Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server.

The time or time-period the observed value is asserted as being true. It is a time period if a Measure-Active-Period (duration) attribute is part of the metric measurement sent by the PHD. Otherwise it is the time stamp sent by the PHD or the time of reception by the PHG if the PHD sent no time stamp.

At least a date should be present unless this observation is a historical report. For recording imprecise or "fuzzy" times (For example, a blood glucose measurement taken "after breakfast") use the Timing datatype which allow the measurement to be tied to regular life events.

Knowing when an observation was deemed true is important to its relevance as well as determining trends.

The information determined as a result of making the observation, if the information has a simple value.

An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

The decoded Mder FLOAT or SFLOAT value from a PHD measurement containing either a Basic-Nu-Observed-Value Simple-Nu-Observed-Value or Nu_observed-Value attribute.

The implicit precision in the value shall be honored. The Mder encoding used in the above attributes provides this precision. The translating software shall honor that precision when generating this value. This element shall be present unless there is an error reported in the Measurement-Status attribute or the Nu-Observed-Value.status field or the Mder encoding represents one of the special values. In that case there is a dataAbsentReason element and the valueQuantity element is not present. Note that not all measurement status values are errors resulting in no measurement being reported here; for example the preliminary or verified status.

Precision is handled implicitly in almost all cases of measurement.

How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.

Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.

The identification of the system that provides the coded form of the unit.

Need to know the system that defines the coded form of the unit.

A computer processable form of the unit in some unit representation system.

The UCUM code needs to be translated from the 11073-10101 code from the device. This translation means that the reporting of units is not future proof.

Need a computable form of the unit that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.

Provides a reason why the expected value in the element Observation.valueQuantity is missing. This could be a 'not-a-number', 'positive-infinity', 'negative-infinity' or an error condition indicated by the Measurement-Status attribute or the status field from a Nu-Observed-Value attribute.

The current values in the http://terminology.hl7.org/CodeSystem/data-absent-reason system do not provide a code that matches the special values 'not at this resolution' and 'reserved'. In those cases one uses the generic 'error' code. If both a special value and a Measurement-Status indicating invalid, not unavailable, or msmt ongoing are received, the Measurement-Status mapping takes precedence.

Codes specifying why the result (Observation.value[x]) is missing.

For many results it is necessary to handle exceptional values in measurements.

A reference to a code defined by a terminology system.

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.

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

A reference to a code defined by a terminology system.

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.

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

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

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.

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

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).

Need to refer to a particular code in the system.

The device used to generate the observation data.

This field will reference the PHD Device.

Reference to the device-related resources that describe the sensor device taking the measurement. This element will point to a Device resource following the Phd Device Profile.

This reference points to the Device resource containing information about the sensor device that took the measurement.

Some observations have multiple component observations. These component observations are expressed as separate code value pairs that share the same attributes. Examples include systolic and diastolic component observations for blood pressure measurement and multiple component observations for genetics observations.

For a discussion on the ways Observations can be assembled in groups together see Notes below.

Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

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).

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.

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.

Describes what was observed. Sometimes this is called the observation "code".

All code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

Codes identifying names of simple observations.

Knowing what kind of observation is being made is essential to understanding the observation.

For each partition:term code pair contained in the Supplemental-Types attribute, a separate supplementalTypesComponent element is generated. The component is not generated if the attribute is absent or empty. The component shall be generated otherwise.

A PHD may send a Supplemental-Types attribute as part of the measurement. This attribute consists of a set of MDC nomenclature codes as partition:term code pairs. Each pair is a code describing something additional about the measurement, such as MDC_MODALITY_SPOT in the pulse oximeter which indicates that the provided measurement is a stable average. An MDC_MODALITY_FAST would indicate that a short averaging is used and the result reported regardless of stability.

Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

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).

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.

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.

Describes what was observed. Sometimes this is called the observation "code".

All code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

Knowing what kind of observation is being made is essential to understanding the observation.

A reference to a code defined by a terminology system.

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.

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

A reference to a code defined by a terminology system.

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.

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

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

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.

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

68193 is the 32-bit nomenclature code indicating a 'Supplemental-Types' value

Need to refer to a particular code in the system.

The information determined as a result of making the observation, if the information has a simple value.

Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

The supplemental information determined as a result of making the observation, if the information is a code.

Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

A reference to a code defined by a terminology system.

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.

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

A reference to a code defined by a terminology system.

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.

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

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

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.

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

For the given Supplemental-Types entry the code here is given by: partition * 2**16 + term code

Need to refer to a particular code in the system.

Provides a reason why the expected value in the element Observation.component.value[x] is missing.

"Null" or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "test not done".

The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

Codes specifying why the result (Observation.value[x]) is missing.

For many results it is necessary to handle exceptional values in measurements.

This component shall be present if the Accuracy attribute is present.

For a discussion on the ways Observations can be assembled in groups together see Notes below.

Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

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).

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.

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.

Describes what was observed. Sometimes this is called the observation "code".

All code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

Knowing what kind of observation is being made is essential to understanding the observation.

A reference to a code defined by a terminology system.

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.

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

A reference to a code defined by a terminology system.

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.

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

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

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.

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

The code for the Accuracy attribute is 67914

Need to refer to a particular code in the system.

Should include the reference identifier for the Accuracy attribute MDC_ATTR_NU_ACCUR_MSMT

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

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.

The information determined as a result of making the observation, if the information has a simple value.

Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

The information determined as a result of making the observation, if the information has a simple value.

Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

This is the value of the accuracy attribute. The value is Mder FLOAT encoded and shall be expressed to the precision indicated by the Mder FLOAT.

The implicit precision in the value should always be honored. Monetary values have their own rules for handling precision (refer to standard accounting text books).

Precision is handled implicitly in almost all cases of measurement.

How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.

Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.

The unit code shall use the UCUM system

Need to know the system that defines the coded form of the unit.

The units for the Accuracy are given by the units of the measurement so this entry shall have the same code as in Observation.valueQuantity.code

The preferred system is UCUM, but SNOMED CT can also be used (for customary units) or ISO 4217 for currency. The context of use may additionally require a code from a particular system.

Need a computable form of the unit that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.

Provides a reason why the expected value in the element Observation.component.value[x] is missing.

"Null" or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "test not done".

The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

Codes specifying why the result (Observation.value[x]) is missing.

For many results it is necessary to handle exceptional values in measurements.

This component gives one of the settings reported in the Alert-Op-State attribute. This attribute is used only by the Pulse Oximeter specialization. The Alert-Op-State attribute is used in conjunction with the Current-Limits and Measurement-Status attributes. The Current-Limits defines upper and lower limit thresholds for a reported measurement value. When the reported measurement value goes below or above these limits, a bit is set in the Measurement-Status attribute is set if the Alert-Op-State attribute indicates that the alert is active for the given threshold. Since it is considered important that if a Current-Limits attribute is present an alert shall be sent went the thresholds are crossed, the Alert-Op-State Bits are only set when the alert is, for some reason, turned OFF for a given threshold. There shall be one such alertOpStateComponent entry for every bit set in the Alert-Op-State attribute. There may be an entry for the defined cleared components as well.

Recall that when creating the code for this entry that the code uses the MDER-Bit setting to be reported along with the Alert-Op-State attribute's MDC code. MDER-Bit 0 is the most significant bit of the attribute value. Since the Alert-Op-State attribute is a BITS-16 value, MDER-Bit 0 would have value 0x8000 and MDER-Bit 1 would have value 0x4000. Only bits 0, 1, and 2 are defined for this attribute. This component indicates if a given alert condition monitoring is turned off.

Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

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).

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.

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.

Describes what was observed. Sometimes this is called the observation "code".

All code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

Knowing what kind of observation is being made is essential to understanding the observation.

A reference to a code defined by a terminology system.

Normally alternative coding systems are allowed but in this case the value is intimately tied to the code. The code represents the feature indicated by a bit setting in the attribute value. which is either cleared (0) or set (1). Thus the value for this entry is itself a binary 'Y' or 'N' code from http://terminology.hl7.org/CodeSystem/v2-0203

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

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

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.

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

This code, which is an alpha-numeric string, is generated by the attribute MDC code, which is 68746 for the Alert-Op-State, followed by a dot (.) followed by the MDER-bit that was set. Given that only three bits are defined in the Pulse Ox specialization that uses this attribute, the code will be one of 68746.0, 68746.1, or 68746.2

Note that this code is an alpha-numeric string and not a decimal number. Think of it like a very-limited OID.

Need to refer to a particular code in the system.

The information determined as a result of making the observation, if the information has a simple value.

Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

A reference to a code defined by a terminology system.

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.

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

A reference to a code defined by a terminology system.

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.

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

This coding system contains only two entries, 'Y' (bit set) and 'N' (bit cleared)

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.

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

If the MDER-Bit is set, the code value is 'Y' otherwise it is 'N'. These are 'state' bits thus both the set and cleared states are reported.

Recall that when the value is 'Y' the alarm or alert is turned off

Need to refer to a particular code in the system.

Provides a reason why the expected value in the element Observation.component.value[x] is missing.

"Null" or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "test not done".

The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

Codes specifying why the result (Observation.value[x]) is missing.

For many results it is necessary to handle exceptional values in measurements.

The Current-Limits attribute gives upper and lower threshold values for the triggering of an alert for the measured value being reported in this Observation resource. This attribute is currently used only in the Pulse Oximeter specialization. If the alerting is not turned off, a Measurement-Status attribute bit is set when either threshold is crossed. The Current-Limits attribute value shall be reported if it is present in the measurement.

The value is expressed as a range. The lower and upper values of the range represent the thresholds.