SmartGuard + Dual Wave = Bolus Cancellation

We first wrote about this a few weeks ago, about first coming across the potential perils of SmartGuard suspending basal and cancelling all remaining bolus insulin (i.e. the extended component of a dual wave delivery) without any prompts to resume the bolus component..

We've had a few SmartGuard initiated suspends during an dual wave bolus since then and, of them, we have, on two further occasions, forgotten to recalculate an extended bolus for the remaining time period post resume. One of these was after an interruption of less than ten minutes (i.e. manually cancelling SmartGuard).

The message in the data file (not the pump screen) is the same as before:-
Suspend Before / At Low will suspend basal and cancel an extended bolus. 

The answer for us is the same:-
We need to manually go back in after basal has resumed and put in a revised Square Wave bolus if necessary.

Ok, I get it, but I'm still concerned:-

We know and understand that we need to think about manually inputting a revised Square Wave bolus following a Suspend before Low.

But - and this is, I think a big "but", there's no obvious warning / reminder message on Resume to prompt you (or whoever happens to be looking after Janki) to do this. There is an alarm in the pump log, but it doesn't make it to the screen...

I'm surprised - the pump is very good (perhaps too eager in some situations on our current settings) to chirp and bleep away, telling you that you didn't complete a bolus data entry, it's still waiting for a BG reading, or that due to a chaotic previous 12 hours, you now need to bank a sensor calibration with a stable BG in the small hours of the morning :-) But there's silence when it comes to the partial loss of a dual wave bolus (unless you're within 10 minutes of a battery change interruption)...

If I'd manually suspended delivery, I think I'd be more likely to remember / think to resume or adjust an extended bolus. But, with semi-automation, comes a break in that feedback loop.... Cancellation is automatic (if you enable the suspend options) and surely a prompt to manually adjust bolus on resume should also be automatic, even if the pump doesn't do the calculation for you? 

Of course, you could argue just rely on high SG alerts. But I don't want to correct at 13.9 and above if possible (in practice it would have to be set higher than this away from home as you might expect a fast carb school / preschool meal to bounce into that range for a short period and too many alarms at school aren't going to go down well and are likely to lead to alarm fatigue) - we might spend the next 24+ hours bouncing from one extreme to the other. I'm not sure we could rely on a rate of increase alarm either. The slower carbs tend to come in, um, slowly and so highs can creep up...

According to the System User Guide, the 640g will show the following message:

Resume Dual Bolus?

XX of YY U delivered. 

Resume delivery of ZZ U for XX:XX hr?

if the square portion of a dual bolus was interrupted and it's within ten minutes of this interruption. The manual is clear that this is the case following a brief battery change interruption, but not clear on what happens following any other cause for interruption (such as SmartGuard). We've had one brief (less than ten minutes) SmartGuard interrupted Square Wave portion of a Dual Bolus and there was definitely no prompt to resume this component.

So in the expectation that, at some point in the future, a firmware patch may be available for the 640g (not unknown for Medical Devices), can we please add the following message on Resume:

Square Wave Bolus NOT resumed. 

Edit Bolus setting now? 

Yes / No

or similar please?

Don't get me wrong, I still like the 640g SmartGuard features and this is just part of the adventure (Stage 2 if you remember!) en route to a fully automated Artificial Pancreas. But, a little tweak may make all the difference, particularly when less experienced carers, such as those looking after Janki at school / preschool, are involved.