List Every Kind of Evidence a Device Produces
Four Truths Data Inventory
Companion to Medical Device Connectivity · Updated 2026-09-29
Use this at the start of a product definition or a connectivity roadmap, to list every kind of evidence the device produces before anyone decides what to expose. Product managers, systems engineers, and clinical or process specialists fill it in together; “Every Device Produces Four Kinds of Evidence” works it on the smart infusion pump. For a continuous renal replacement therapy machine, a surgical robot, or a blood bank refrigerator, the same four rows apply; only the items change.
Fill in the four truth rows in the order given. List each item this device produces. Record where each item lives today. Name who needs it.
The Four Truths Data Inventory: every kind of evidence the device produces, and where it lives today.
| Truth | Look for | What this device produces | Where it lives today (screen, paper, internal log, file, interface, another system, nowhere) | Who needs it |
|---|---|---|---|---|
| Clinical truth: evidence about the patient or specimen | Heart rate; blood pressure; oxygen saturation; glucose; waveforms; imaging data; lab results; temperature; respiratory parameters | |||
| Therapeutic truth: evidence about an intervention performed on or for a patient | Infusion parameters actually delivered; ventilation settings and changes; dialysis treatment parameters; energy delivered; medication administration state; treatment cycle; therapy pauses, overrides, and completions | |||
| Operational truth: evidence about the work the device performed and the surrounding workflow | Cycle started and completed; pass or fail result; operator; asset identity; location; consumable identity, lot, or expiration; probe or instrument identity; utilization; turnaround time; queue state; cleaning or disinfection cycle; device availability; alarm acknowledgment; workflow handoff; chain of custody | |||
| Assurance truth: evidence that the device itself can be trusted | Software or firmware version; secure boot status; cryptographic identity; configuration version; calibration status; maintenance status; self-test results; patch level; vulnerability status; certificate state; software bill of materials (SBOM) component identity; update history; tamper evidence; service history; cybersecurity events |
After the inventory, record a rating for each truth. The ratings are conceptual judgments that help a team compare devices; they aren’t scores and can’t be added up.
Conceptual ratings for this device (High, Medium, Low, or Very high): judgments for comparing devices, not scores.
| Clinical truth | Therapeutic truth | Operational truth | Assurance truth |
|---|---|---|---|
Any operational or assurance item that lives only on the screen, on paper, in the device’s internal log, in someone’s re-keying, or nowhere is an operational blind spot the product creates for every customer. Put each one on the roadmap ahead of features that add data nobody has asked for.