Is this a glitch in the Omnipod 5 software?

[PattiEvans]

To give some background I've been using pumps for almost 12 years. First the Roche Combo pump (I had 2) and then the Omnipod Dash. Last June I was asked if I'd like to go on HCL with the Omnipod 5 and Libre 2+. An opportunity I jumped at, though in fact my control had always been quite good. However, I was disappointed in the level of control I had with the HCL, it seemed too ineffectual in it's corrections and so forth, plus I wasn't happy with the "target" of 6.1 as I've always had a target of 5.5. Might seem negligible, but I found I was running in the 7s/8s a lot of the time on the Omnipod rather than the 5s where I am comfortable. So, a month ago I decided to revert to manual. Unfortunately I still couldn't lower the target on the software.

Anyway, I've relied on my pumps to do the maths for dosing all the years I've been on a pump. Recently I've noticed that quite often when BG has been in the 9s or 10s I've asked it to do a correction and it's recommended 0u as I have an amount of insulin on board already. Fine - might be leftover from a meal dose.... however, this was happening in the morning when I had had no insulin since the previous evening's meal. It then dawned upon me that the IOB is actually my basal for that hour which is supposed to keep me level, it's not supposed to correct my BGs. Once I realised this, I could work backwards within the calculations and administer the amount needed to lower my BG. However, surely the pump should be calculating a correction, not relying on my residual basal for the hour.

I can't help thinking this is a glitch in the software. Anyone else noticed?

 

[everydayupsanddowns]

Really interesting observations @PattiEvans

I have no firm evidence for this, but I wonder if this might be a ‘safety’ measure either required by the FDA, or something that helps to get it through one or other regulatory process?

You might be interested to know, for example, that the MM780G algorithm does something very similar.

It basically makes every bolus into a Superbolus (remember that thing when you would add the next hour or two’s basal up front to your meal dose, and set a 0% tbr to front-load a dose and help to reduce a post-meal spike?)

The MM780G uses what they call ‘safe bolus’, and essentially it sets a 0% TBR for 1-2 hours after almost every single bolus. As soon as I spotted that, I had to tweak my meal ratios to add the ‘missing’ basal back in.

I think the device manufacturers are assuming that they can always add the insulin back in later if it’s needed… but they can’t take it out once it’s IN. So they basal-suspend early, and top-up with extra insulin if needed.

If BG is low-ish before a meal, the MM780G will reduce the bolus by a lot. Sometimes I’m unable to prebolus because pretty much 0u is being recommended for 40-50g of carbs. I have to remember to dose later when my BG has begun to rise slightly

 

[PattiEvans]

It basically makes every bolus into a Superbolus (remember that thing when you would add the next hour or two’s basal up front to your meal dose, and set a 0% tbr to front-load a dose and help to reduce a post-meal spike?)

I do remember the superbolus being discussed in DSF... but I don't think it's that. I'd type all the calculations out but it's endless and I'm probably wrong, I just don't understand how there can be any bolus on board if I have administered none for 14 hours plus!

 

[trophywench]

The superbolus - MUCH discussed in the pregnancy forum ISTR ! Hardly required by non pregnant ladies though!