Continuously rethink and challenge even proven design concepts
We gave Hannes almost complete freedom when it came to developing a solution and he really made the most of this opportunity. In collaboration with our development department, he put almost all of the existing components to the test. He went on to replace not only the detector system, but also the thermal emitter, which he replaced with a more cost-effective LED version. The system design also came under scrutiny, as Hannes wanted to work out the optimal positioning of the detector and emitter and to establish an improved measurement cell as a result. The aim here was to get as much light output as possible on the surface of the detector and to prevent any dead space in the gas ducts, as these do not allow for any gas exchange, which can end up contaminating the measurements.
Tests back up Hannes’ concept
Hannes developed a LabVIEW program to test how the changes will improve the system. This program makes it possible to control and parameterize the system hardware and to read out and store all of the important measurement results. This allowed Hannes to compare values such as the noise behavior, rise time, temperature dependency and long-term stability of our new capnography module with the behavior of the tried-and-tested CAP201. And the evaluations showed that the new module achieves good to very good values with lower costs and a smaller construction space.
The noise behavior remains significantly below the standard limit, the rise time is very quick and the system is stable over time, delivering valid results over a long period. The system could also be produced a lot more cheaply than the CAP201 thanks to the use of the LED emitter.
