I noticed something strange about the OmniPod PDM. It only considers a correction bolus to be “insulin on board”. Any bolus for food does not count as IOB. If I eat lunch and get the right bolus for it then test an hour later I will be above my target BG value. If I wait another hour the meal bolus for lunch will catch up and my BG will be good. The problem is that when I test 1 hour after the meal and am a little high the PDM will suggest a correction bolus even though the lunch bolus is still active.
So what possible reason could there be to design the OmniPod system this way? If there was a good reason for it I could accept it and just manually override some of the correction bolus during postprandial BG rise. So please help edu-ma-cate me on why IOB doesn’t include meal boluses.
I’ve noticed it, too, but I guess I assume the PDM calculates all the meal bolus as being “taken up” by the carbs that were eaten and thus none of it is left on board. But this really sounds like a good question for your trainer or CDE. I’m out of touch with mine and don’t see my endo for another 6 weeks, so if you find an answer please post it for the rest of us.
Now that I have read this, I see exactly what you’re saying. I actually thought my PDM was broke, now I realize that just what you’re saying - it only suggests the IOB after a correction, not meal.
But then that brings a new question: Since we know this is what it is doing, what “rule” to we follow if we are too high for a post-meal reading? (i.e. I was 205 2hrs after my breakfast of 36g of carbs, took 1.5u of the 2.1u the “correction bolus” suggested and ended up 68 and dropping by lunch.) When I say rule, do we mentally do something like take the number and subtract a post meal factor like 140 or 170 and divide that by our correction factor? (example: 205-170=35 then 35 divided by 50 = 0.7, so take a 0.7u bolus?)
I’d say if that happens on a regular basis, then you might need to adjust the “correction factor” in the PDM. I’d ask my trainer and/or endocrinologist.
