EBME Forums Forums Maintenance Technical Assistance Cardiac output

I'm looking for advice on testing the calibration of CO/PiCCO monitors, using a test simulator. Specifically, which parameters should be replicated from test simulator to monitor. Any insights or tips you can share would be really helpful!

Isn't calibration carried out at the monitor these days? That is, during setting up with an actual patient?

I'm not sure that anything you can do away from a patient would be any improvement on that (because that way you are testing the complete circuit as used in a "live" situation). As you know, the PiCCO patient set up (tubing etc.) is relatively complex.

Back in the "old days" we used to calibrate the transducers of invasive BP systems separately. That is is, just the monitor and the transducer (via its cable). Different than Cardiac Output, I know. There were a few testers (Bio-Tek et al) that could inject a signal into the monitor via a suitable cable (but that, of course, only checked the monitor).

Which monitors are you using? And are the nurses complaining?

Thanks for your reply, Geoff. I was referring to testing as part of PPM performance verification, to ensure accurate and reliable performance of the device - after all this is an EBME forum!

Just the monitor, then. Any clues in the service manual?

Service manual...This is where the problem arises. There is no service manual available for this kit. Mind if I PM you Geoff?

H'mmm ... I wonder if the manufacturer is one of those who declared that the monitor "does not require servicing" (or some such display of arrogance)?

PM by all means ... although I much prefer discourse in open forum (on the grounds that others may be interested, and (or) make a contribution).

As per original post, I'm keen to connect with those who've got hands-on experience testing CO/PiCCO monitors - from an EBME perspective with annual functional/calibration checks. By the way, my experience with testing various manufacturers' CCO monitoring has been pretty straightforward - set up the simulation test kit, connect it to the monitor, and then compare the results - easy. The crucial parameter to ensure is correct is the CO volume. Interestingly, the manufacturer of a recently acquired PiCCO monitoring system in our hospital claims that it doesn't matter if the parameter value collected by the PiCCO monitor differs from the value on the test kit. They've mentioned that as long as the monitor displays some kind of value, that's all that matters. Any thoughts or similar experiences?

"Pretty straightforward" ... yes; as it should be. Is your simulation test kit anything special, or something we should all be familiar with?

That's interesting what the manufacturer is saying. Going back to my thoughts about the complete calibration being done at the monitor, perhaps (self calibrating during pre-use checks). Some may say that renders your own PM checks redundant ... to which I would respond that they would be missing the real point of PM (which is, in a word, reassurance). Just as long as PM checks remain, as you say, pretty straightforward (that is, performance checks, rather than calibration* per se).

Does your test kit work OK with the new monitor? How do the results compare? Not too far out, I hope.

If I were in your position, I would push the manufacturer a little on the claim made. How do they test the monitor, I wonder?

* Although if PM checks include calibration, that is of course no bad thing.

Absolutely agree with you! When it comes to PMing static state devices, the main goal is to ensure the device is functioning as intended. Just because it zeros doesn't necessarily mean all the other functions are working correctly.

We're using the same test kit the manufacturers recommend. For instance, if the test kit is set for a volume of 5LPM, the monitors consistently show readings of 6.5 LPM or above. In my experience with other manufacturers, readings have always matched the test kit precisely.

I'm getting the impression that the technical services provided by the manufacturers might not fully grasp the clinical aspects of CO.

Does anyone else have experience with testing (EBME planned maintenance checks) CO monitors?