## DeviceComponent Profiles
### Scope and Usage
These DeviceComponent profiles are part of the Point-of-Care Device General Implementation Guide. A set of DeviceComponent and DeviceMetric resources represent the physical or logical structure of a medical device in a containment hierarchy.

A compliant device is represented by multiple [DeviceComponent](http://hl7.org/fhir/devicecomponent.html) resources according to the MDS, VMD, and Channel DeviceComponent profiles. A top-level MDS DeviceComponent makes the root node of the tree structure. There shall be one or more VMD DeviceComponents at the VMD level, and one or more Channel DeviceComponents per VMD at the Channel level. The profiles define the following rules:
* `DeviceComponent.type` shall have a coding from the ISO/IEEE 11073 MDC device nomenclature. The [Rosetta Terminology Mapping Management System](https://rtmms.nist.gov/rtmms/index.htm) (RTMMS) lists available codes. `DeviceComponent.type.coding` allows additional coding from other code systems.
* `DeviceComponent.source` shall be present and refer to a Device resource according to the PoC Device profile.
* `DeviceComponent.parent` is a reference to the next upper level DeviceComponent resource. For Channel DeviceComponent, it shall be present and refer to a VMD DeviceComponent. For VMD DeviceComponent, it shall be present and refer to a MDS DeviceComponent. For MDS DeviceComponent it's optional and may refer to another MDS DeviceComponent as a composite MDS.
* If multiple instances of the same VMD or Channel type exist, the Instance extension allows to define a sequence.
* To assign a common color representation for all metrics in a Channel, the Color extension can be used. It gets a code from the [DeviceMetricColor](http://hl7.org/fhir/valueset-metric-color.html) value set.

### Content
|StructureDefinition|Description|Example|
|---|---|---|
|{{link:DoF-PoCD/MdsDeviceComponent}}|Characteristics and operational status of a point-of-care device|{{link:DoF-PoCD/PhysioMonitorMdsDeviceComponent-example}}|
|{{link:DoF-PoCD/VmdDeviceComponent}}|Characteristics and operational status of a medical-related subsystem of a point-of-care device|{{link:DoF-PoCD/ECGVmdDeviceComponent-example}}|
|{{link:DoF-PoCD/ChannelDeviceComponent}}|Characteristics and operational status of a group of metrics|{{link:DoF-PoCD/HeartRateChannelDeviceComponent-example}}|

|Extension|Description|Example|
|---|---|---|
|{{link:DoF-PoCD/devicecomponent-instance}}|Instance number for multiple components of the same type|{{link:DoF-PoCD/BloodPressureVmdDeviceComponent-example}}|
|{{link:DoF-PoCD/devicecomponent-color}}|Color for representation of contained metrics|{{link:DoF-PoCD/ECGChannelDeviceComponent-example}}|