Regarding the development version of FHIR (v0.4.0-xxxx) there may be a problem with the Observation resource.
Consider a Device having some DeviceComponents each delivering specific DeviceMetrics. How do I create an Observation and specify its type to be of a specific DeviceMetric or DeviceComponent?
We have defined the DeviceMetricObservation profile, which derives from the existing Observation resource. This profile includes the reference link to the DeviceMetric where the observation is coming from. You should be able to see it under Conformance Packages tab in the Observation resource page.
