EBME Forums Forums Maintenance Technical Assistance Baxter colleague low occlusion pressure

Sounds like the Colleague pump is a bit like purchasing an electric car. You get a government incentive to offset the higher cost; it gives the impression of reducing carbon emissions; but when your wanting to commute more than 50 miles each day it's a complete waste of space.
A medical device should be able to do exactly what it says on the box without any glitches that prevent continuous use.

Anyone here ever worked for medical equipment R&D dept in major corporation?

Well, not me, that's for sure.

But how about this link?

It looks like that magazine has being going for thirty years, yet I've only just discovered it. So it's true ... you (can) learn something new every day.

Texas Instruments do some brilliant (and, or course, containing modern - "latest stuff", in fact - technology) application guides. But you need to register with them (which shouldn't be a problem). You might also want to keep an eye on (bookmark or whatever) this interesting blog).

And lastly (in case you've missed my earlier plugs ... how come?), don't forget Tim Gee's blog.

"Luck favours the prepared mind." - Louis Pasteur

Hi guys, it's the OP back with a little by way of an update.

Having to continue testing and process pumps through the relicence system I have made further discoverys.

A pump failing our imposed occlusion pressure limits of 400 - 550 mmHg can be frigged to pass (eventually) by re loading the set.

Normally I'm lucky and the Baxter will pass, borderline cases normally pass on a second attempt. Some can take a few attempts before scraping a pass.

I am now concerned that this is possibly a far from acceptable situation and have looked at the results further.

The pump on test at the moment is displaying characteristic results as follows;

New BAXTER giving set loaded
Device flow tested at 10ml/hr for 2 hours
Device occlusion tested - 375mmHg FAIL UNDER SPEC
Device occlusion tested - 383mmHg FAIL UNDER SPEC
Device occlusion tested - 383mmHg FAIL UNDER SPEC
Set removed and reloaded in same position
Device occlusion tested - 368mmHg FAIL UNDER SPEC
Device occlusion tested - 308mmHg FAIL UNDER SPEC
Set removed and relocated onto unused section and reloaded
Device occlusion tested - 630 FAIL OVER SPEC
Device occlusion tested - 563 FAIL OVER SPEC

Device is currently back on flow test to see if the occlusion pressure drops as expected.

Can somebody tell me how the baxter detects occlusion pressure and if the test could be influenced by the working of the giving set.

Yeah, I think I can remember colleagues called Baxter at school. Seems like there were at least one of those t*****s in every class!

The previously mentioned device has been flowing 9.9 ml/hr for 4 hrs, I'v subjected it to a number of occlusion tests, the results were as follows;

540
525
525
525
540
540
540

So - therefore it scrapes a pass. But should it?

They're all within your spec. and also within few percentage points of each other. So reproducible, at least. Did you have to "frig" this time, or was the test a reasonable one?

You started off this thread saying you were getting low occlusion results. Now they appear to be approaching the high end of your spec. So what's changed in the way you're testing them, I wonder? Or is this just the kind of scattered results that these Colleague pumps normally give?

What do you do ... an initial occlusion test (to see if the thing needs adjustment), then flow tests at low, medium and high rates (say), then a final occlusion test?

I'm also wondering if you get similar occlusion alarm results at low, medium and high flows. I would suggest that low flow occlusion presents the greater threat to the patient, in case a harmful bolus gets released as, when, or if the occlusion is relieved.