Omnipod app UI snafu

[Carlos]

Saw this in a blog I read occasionally

UIs matter

Well, this is a horror story about coding incompetence. There is this nice gadget that can be controlled from your phone to automagically dispense insulin, a real boon to diabetics. You just type h…

freethoughtblogs.com

Apparently the Omnipod app disregards the decimal point for the bolus dose input if it isn't preceded by a zero, so if you type .50 it will interpret it as 50, and inject 10 times the expected value.

I am not a pump user, and I don't know how often users will inject 0.5 units, and how likely they would be to type that as .50, so probably this is an fairly obscure corner case, but surprising and potentially with very serious consequences.

 

[rebrascora]

Isn't there a maximum dose setting on pumps which you have to confirm if you are exceeding it. So say 20 units, which would mean that for 50units would need you to override the max dose by confirming it and you are extremely unlikely to bolus 0.2 units.

I confess I have not clicked and read the article in full because I invariably find these things want you to accept cookies and I am very wary of such things.

 

[Bruce Stephens]

Isn't there a maximum dose setting on pumps which you have to confirm if you are exceeding it.

The default maximum is apparently 15 units. I tend to agree that I'm struggling a bit to imagine why I'd bolus 0.15 units (which would do approximately nothing for me), but maybe if I used a pump the reasons would be obvious?

There's an advisory:

Field Safety Notification - November 2023 | Omnipod

www.omnipod.com

 

[helli]

With the pumps I have used, I rarely enter a specific dose. I usually use the integrated bolus calculator based on BG and carbs. This makes it easy to have different ratios at different times of day and have more precise ratios without having to divide by 12, 13, 15, … at different times of day,
So, it is not often that I would input .5 units although based on my I:C ratio, my dose is often less than one unit.

My max dose is 10 units so, in the OmniPod snafu, I would not get 50 units. But, as I would enter “.5” (why type an extra zero at the end if you are not willing to put one at the start?), I guess I could get 5 units which is a high dose for me.

 

[Bruce Stephens]

I usually use the integrated bolus calculator based on BG and carbs.

It's possible that's what they mean, so it's 1g multiplied by 0.15, or something like that. (Though I imagine bolusing for 1g of carbs is pretty unusual even when you can.)

 

[Bloden]

Thanks for the heads-up @Carlos. I haven’t started using the Omnipod 5 yet, but it’s a great reminder to check, check, check before pushing that final button. 🙂

 

[Carlos]

It does seem like a corner case, but typing .5 would inject 5 units, which would probably not raise an alarm, but is a significant over dose compared to the intended value. What is the feedback after the injection, would the user notice immediately, or could this go unnoticed?

 

[trophywench]

Well I'd certainly notice, bearing in mind I rarely need more than an average of approx 20u a day, max probably 25u (if I've had too much carby food! Like I had a mince pie in the afternoon then Pete decided he was making us mac cheese (he has to, not in my repertoire) for dinner, oops) and using a pump to deliver it that includes both basal and bolus insulin. Although my previous pump allowed hourly basal rates to 3 decimal places - boluses were only to 1. Current and previous pump - 2 places basal, 1 place bolus/correction.

 

[nonethewiser]

Isn't there a maximum dose setting on pumps which you have to confirm if you are exceeding it. So say 20 units, which would mean that for 50units would need you to override the max dose by confirming it and you are extremely unlikely to bolus 0.2 units.

I confess I have not clicked and read the article in full because I invariably find these things want you to accept cookies and I am very wary of such things.

Your not wrong there @rebrascora

On previous Omnipod PDM & with Dash now there's a max bolus limit which you can set yourself to avoid errors, if you enter a bolus dose above that limit a message will appear warning you that it's above your preset limit, at this point you can override it if you chose to.

Can't see this feature being absent on this new phone app being discussed here.

 

[everydayupsanddowns]

It does seem like a corner case, but typing .5 would inject 5 units, which would probably not raise an alarm, but is a significant over dose compared to the intended value. What is the feedback after the injection, would the user notice immediately, or could this go unnoticed?

Yikes!

I nudge with .5u .7u or .8u surprisingly often, and am just the sort to omit leading zeroes 😱

 

[Tdm]

That really should have come out in testing!

 

[Carlos]

That really should have come out in testing!

Test coverage of UIs and how real users might (mis)use them is notoriously difficult. Having said that, I almost always omit the leading zero when inputing numbers on any kind of computer UI, and have never come across any UI that behaved as the Omnipod app does.

 

[PattiEvans]

I'm sorry, I don't really understand this. I have the Omnipod Dash and when you click on "bolus" it asks you the amount of carb, and you enter that, then it asks you your current BG and you enter that. It comes with a decimal point, so if I enter 5 it just thinks my current BG is 5.0. It then calculates your dose for you. As far as I can see you do not ever enter a dose because if you want a correction you just omit the number of carbs and enter your current BG. Unless I am being stupid I do not see any way to enter an amount of insulin to be dosed. The Omnipod 5 may be different I suppose. I saw one briefly last night, but due to the number of people crowding round the table I didn't have time to inspect it in detail but it looked much the same. Also when setting up the PDM you tell it the maximum dose. If I try entering my BG as 50, which I can then I get a blooming big warning!

So basically I don't see how you could do it.

The original article is UScentric, so maybe the US version of the pump is different?

 

[PattiEvans]

Having re-read the letter from Insulet then I can sort of see how it would happen, but my pump would NOT deliver it without a huge warning popping up.

 

[nonethewiser]

I'm sorry, I don't really understand this. I have the Omnipod Dash and when you click on "bolus" it asks you the amount of carb, and you enter that, then it asks you your current BG and you enter that. It comes with a decimal point, so if I enter 5 it just thinks my current BG is 5.0. It then calculates your dose for you. As far as I can see you do not ever enter a dose because if you want a correction you just omit the number of carbs and enter your current BG. Unless I am being stupid I do not see any way to enter an amount of insulin to be dosed. The Omnipod 5 may be different I suppose. I saw one briefly last night, but due to the number of people crowding round the table I didn't have time to inspect it in detail but it looked much the same. Also when setting up the PDM you tell it the maximum dose. If I try entering my BG as 50, which I can then I get a blooming big warning!

So basically I don't see how you could do it.

The original article is UScentric, so maybe the US version of the pump is different?

Use Dash also & you can bolus without putting in carb value & glucose reading, but there's no way you can exceed max bolus dose set up by yourself without a warning message coming up, as said earlier can't see it being any different with Omnipod 5 apps.

 

[PattiEvans]

Thanks for that. I'd never tried to bolus without taking the PDM "advice" after putting in details, but after some fiddling around I can see how you'd do it. Again though, as you say, the warning would come up.