Write Down What the Device Means Before Choosing a Protocol
Event/State/Command Modeling Worksheet
Companion to Medical Device Connectivity · Updated 2026-09-29
Use this before choosing any protocol, to write down what the device means; the mapping to standards comes last. Systems and interoperability engineers fill it in with clinical or process specialists; “Decide What the Device’s Data Means Before Choosing the Protocol” works it on the automated probe reprocessor.
Fill in the rows from top to bottom. Use the words the device’s users use. Leave the last row until every other row is complete.
The Event/State/Command Modeling Worksheet: define what the device means first, and map to standards last.
| Element | What to record | Entries |
|---|---|---|
| Events | Each thing that happens, named in the user’s words (cycle started, chemistry test failed, specimen aspirated, bed-exit alarm raised), with its trigger, its fields, and who consumes it | |
| States | Each state the device and its key objects can be in (idle, running, faulted, awaiting release), the allowed transitions between them, and which transitions are safety rules the device enforces locally | |
| Commands | Each instruction the device accepts from outside, who may send it, how the device validates it, and when the device refuses it | |
| Measurements | Each value, with its units, range, resolution, and the method that produced it | |
| Settings | Each configurable parameter, who may change it, and how the device records a change | |
| Identities | Which identities from the Device Identity Matrix each event and measurement carries | |
| Time | The clock each record uses, how that clock is synchronized, and how a record shows that its time may be wrong | |
| Quality and calibration | How each value shows its quality, and the calibration state behind it | |
| Context | The patient, specimen, or workflow association each record needs before it means anything | |
| Provenance | Whether each value was measured, entered, inferred, or derived, and its transformation history | |
| Failure semantics | What each event or command means when it arrives late, twice, out of order, or not at all | |
| Standards mapping (last) | The standard, profile, or interface each element maps to, with its version, and the elements that don’t map to anything yet |
If a row can be filled in only by naming a protocol, the model isn’t finished. Keep these definitions in the device’s own model, and design the transport as a part the team can replace without changing them.