Neonatal patient ventilator
Verification for neonatal patient ventilators
Starting situation
For a neonatal ventilator that has been for years on the market, the technical documentation needed to be brought up to date in terms of new applicable standards.
Our customer defined the functional specifications for several model variants. To provide documentary evidence for all these extensive specifications, evidence (through comprehensive verification) had to be provided that all requirements were met. Without this detailed verification, the responsible authorities and notified bodies would not approve any further market authorization for these devices, resulting in a ban on their production and sales.
For this urgent and challenging task, our customer chose IMT due to our many years of experience and expertise in the design of medical ventilators.
Project objectives
The customer specified more than 900 functional requirements in their neonatal ventilators: various settings, accuracy requirements, ventilation patterns, alarm signals and states, measuring ranges, safety restrictions, and many other parameters.
For this large sum of requirements, it was necessary to partially recreate the verification test procedures to prove that the devices in fact fulfill all these functions in complete detail. For the required proof of traceability, a software tool had to be used, which could demonstrate the traceability of the created test procedures to the functional requirements and the risk analysis.
Of course, the test procedures not only had to be defined, but the tests also had to be carried out as proof.
Technical implementation
To fulfill the traceability requirements, IMT first imported the functional specifications and the risk analysis together with the risk control measures into an ALM tool (Helix, Perforce™). The tool was then used to create corresponding tests and subsequently, their results were documented to automatically generate a “traceability matrix” from the tool at the end.
After the review of the changed requirements and the test runs, it became apparent whether these functional requirements were at all verifiable and correctly written. This resulted in numerous adjustments of requirements and the discovery of improvements that were to be addressed in an updated software. To achieve all this, close cooperation with the client and active, transparent communication was crucial for the success.
It turned out that several tests had to be rated as failed as the results differed from the expected outcomes. These cases were iteratively resolved with the customer, which required two to three iteration loops, depending on the ventilator model.
Results
The entire test procedures developed by IMT could be handed over to the customer, along with the documented proofs of the implemented tests, which were finally all declared as “passed”. With this professional foundation, the customer can integrate any further adaptations that occur in the future lifecycle of their devices and test further software modifications with clear traceability.
