Profiles and closed-looping

Diabetes gives challenges in so many ways…and swinging basal/ISF adjustments during hormones is one of them.  We don’t just seem to have changing basal/ISF needs at one time of the month…it actually seems closer to twice a month (ovulation and menstruation both seem to have their own needs).

Prior to looping at all, we simply adjusted basal/ISF on the fly.  For ourselves, usually a simple basal change seemed to adequately compensate for what was needed and usually we could keep isf constant.  We eventually got tired of hand-typing in the profile changes, and we instead created profiles A and B to switch between.

Things got even more complicated when school vs weekends became an issue too.  With school stresses and team sports activities, school days would always bring a need for a large amount of extra insulin in the morning (“oh my gosh, what should i wear today?  am i going to be late to class? do i have everything i need this morning?” seems to make her BGs spike) and then a corresponding decrease in the end of school day (all the sports activity, walking around campus finally cause a BG drop just as the day ended).

Balancing out the various profile changes has been a minor juggling act.  School day with hormones?  Which hormones are we getting?  Will she even want to discuss where she is in her cycle with me?  If she doesn’t want to discuss with me…how am i going to help with basal adjustments going forward (because each month isn’t always exactly the same)?  This has been a real ongoing issue to tackle.

When we started Loop, we originally were about a month into the school year and that school morning spike was BRUTAL.  To deal with the difference between a school vs weekend profile, we had to set up two different Loop apps on the phone.  We gave each different icon photos and names so that we could tell them apart visually and quickly.  The weekend Loop has a big W for a logo and was named Weekend.  She got quite adept at knowing on Friday and Sunday nights to switch between the two loops…but there were definitely times we forgot and had some less than stellar looping as a result.  Nothing dangerous, just not optimal.

As school went on, her morning nerves lessened and we’ve actually grown to the point of not needing separate school vs. weekend profiles.  Loop app can handle the adjustments without a separate profile.  So, we started using a single Loop app again and things went well.

Until the hormones started to rage.  The periods are now regular, and the associated basal/isf changes with them became more pronounced.  We are definitely finding differences between times of month and basal adjustments needed.  And just as all this was coming along, we decided to try OpenAPS.  Because why not throw more complications in at once?

Now here is where things get complicated.  OpenAPS has two “advanced” features that are called autotune and autosens.  You can choose to run your closed loop with them, or without them.  Neither are mandatory parts of the closed loop.  They sound the same, but work subtly different.  We have had both of them enabled on our loop.

Autotune starts with your PUMP’s profile at midnight (technically 12:05am).  It looks at the previous day’s happenings (by pulling data from Nightscout).  Based on that analysis, autotune sets up a NEW autotune-adjusted profile for your day ahead.  Hour-by-hour for the whole day ahead, your rig has an adjusted set of basals and ISFs to use.  Autotune cannot change your new profile by any more than 20% of your pump’s profile that is has current at midnight (that’s hard-coded into the autotune code).  The thing to realize, therefore, when autotune is enabled in your closed loop…changing anything in your pump profile during the day WILL NOT result in changes to the profile that the loop is using to calculate your  needs.  Changes to your pump settings will only be read and considered at midnight and applied the next day as part of the new autotuned-profile.  So, if you have a sudden need for a significant increase in basal during the middle of the day (took a steroid medication?  on a dextrose drip?)…you may need to consider making changes to your autotune, as discussed later in this post.

Autosens will automatically adjust your basal and ISF settings, similar to autotune, by a certain multiplier you specify.  The defaults are no more than 1.2 increase, 0.7 decrease.  (These defaults can be changed in the preferences.json file pretty easily.)  The difference is that autosens runs all  the time, not just once per day.  Autosens goes back on the previous 24 hours of data, excluding times of food influence, and looks to see if basals or isf might need adjusting.  Autosens is a more immediately-acting impact on your closed loop’s settings than autotune, since autosens runs continously.

The question is why am I telling you all this?  Well, this week Anna got hit with her period and a vicious head cold all at the same time.  Things were going along just fine before the cold came.  In fact, I didn’t even see her period reflected in her BGs like I normally do to start with…OpenAPS seemed to be handling it just fine.  The problem became when the head cold hopped on board with it.  A couple nights ago, Anna’s BGs hung out around 120 mg/dl all night, just below our high alarm level (130 mg/dl), even though her target is set to 90 mg/dl.  She was carrying positive IOB the whole time with it.  A sure sign that her basals and/or ISF needed some adjusting.  We went into the next day, and I was making adjustments on her pump the whole time.  Things weren’t getting worse…but they weren’t changing like I expected.  Even though I was putting in much higher basal rates in the pump…openaps was seemingly ignoring my pump changes.  I could see in the openaps pills and loop functions, the higher basal rates just weren’t being considered.  I was stumped.

Finally, I realized something I hadn’t understood before.  Autotune basically was locking me into a basal/isf profile each day at 12:05am.  No matter what I did in the pump settings that day, my basal rates and ISF were only going to change if autosens decided to adjust them dynamically.  And those adjustments were capped at 20% increase and 30% decrease.  So…that explained it.  All my little button pushing all day wasn’t going to make an impact.

The good news is that last night at midnight, autotune took all of yesterday’s insulin resistance and higher basal needs and made some adjustments for us.  Last night, she didn’t hang out in the 120s.  She was near target the whole time and not holding IOB.  Today has been better, too…pretty much at target.  And we didn’t do any profile adjustments.

This whole experience presented me with some important what-if scenarios worth exploring:

  • “What about those times where you absolutely need to change your mid-day basals for some reason?”  Maybe you need to start a new BG-impacting medicine or you end up needing a dextrose drip?  Well, you can turn autotune off so that you can manually use your pump to adjust settings immediately for your loop.  But, you do need to know how to navigate your rig and openaps in the event you want to make immediate changes.  So, setting up a way to remotely login through your phone is a really good step.  You can also simply turn off your loop…that’s always an option.
  • “What can I do to help situations that normally require different basal profiles (like hormones or school)?”  Well, you can still use different profiles, but you just need to be aware that the change in profile won’t really become effective until the next day.  You can also allow autosens to make greater adjustments than the defaults (change your preferences.json accordingly).  That will help in situations like hormone surges hitting where the change might be greater than 20% increase needed in basals/ISF.
  • “What happens with a site failure or bad insulin?  Will that mess up my next day?”  Yes, that could cause problems.  Will they be horrible?  Probably not, but it may be worth turning off autotune and/or autosens when you have a bad site failure or bad insulin that causes your BGs to be artificially high.
  • “Do I even still need two profiles?”  The answer is probably “it depends.”  I’d use the Medtronic 670g pump as an example of where openaps’ autotune and autosens is headed.  User needs to provide very little input (really just a starting point once), and then all the subsequent adjustments are made based on data collected from the previous day(s).  Autotune and autosens seem capable of that to me…but they will need your help to provide sensible allowances (maybe more than 20%) to make those changes, good inputs (log carbs and doses accurately), and perhaps a little patience when a period AND head cold come at the same time.  🙂  I’ll report back later when we have more time under our belt with openaps running through these situations where we normally would have switched profiles.  But, so far, I’d say it handled the period and head cold situation pretty well.  The failing was in my lack of patience and my lack of understanding for how autotune was working.

So, I am writing all this as kind of a learning lesson about how the different looping systems handle the information.  It caught me by surprise, so I thought it was worth noting.  Loop will allow you, within the app, to immediately change your basal and isf settings at any time.  And it will immediately use those new settings.  If you have autotune/autosens enabled, OpenAPS will dynamically be watching and adjusting 24-7 based on how your BG impacts have been happening (or not happening).  At times, that may mean a slight delay in seeing some of the larger changes to pump settings that you previously were used to being enacted immediately when you entered them (like Loop).  The plus side is that you won’t have to be the one calculating the needed change or pushing the buttons to make it happen.  OpenAPS will do that for you.  You can mitigate the effect of the delay by giving the default settings more room to make adjustments.

Am I scrapping autotune as a result of this experience?  Nope.  I’ve still liked the results I’ve gotten from the system.  I have widened my autosens allowances from default settings to help with the hormones and head colds more.  And, I also know that I’m not going to change basals/ISF on the pump during the day (because it won’t do anything anyways while autotune is enabled).  Instead, I’ll be more apt to look at my autotune results and make adjustments at the end of the day when I feel it is necessary.  Thus far, I don’t think that I need to.

I’ll keep tabs on this and report back.




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