We suggest the adding a new item for device operational status to the DeviceMetric resource. Currently, this information can be provided by the statusReason item of the Device resource.

We look at this from the perspective of an insulin pump. We understand that a new device should be defined as a Device item when it is added to the system. At this point the status of the devices is for example "in stock | in use". When an insulin pump defined in the system is in use, its operational status changes quite often. This status can be "online | paused | standby | offline | not-ready | transduc-discon | hw-discon | off"

The current implementation does not support thinking like this, as the exact state of the device can only be described in the Device item. The current implementation leads to a situation where the entire Device item has to be updated quite often in case of insulin pump.