Loop -- a dynamic answer to a dynamic problem


After six months of using Loop, my latest 14-day overnight blood glucose lines have dropped into an ideal and sustained range. The average BG (midnight until 1 p.m.) runs from 86 mg/dL (4.8 mmol/L) to 105 mg/dL (5.8 mmol/L). The second half of the day is a bigger challenge as that’s the half I eat my two meals.

Overall, I would not choose to stop Loop. I’m still learning (aren’t we always?) as I experiment with “eat-soon” mode, insulin sensitivity settings segmented by time of day, and duration of insulin action. I’m still tinkering with these settings and learning more.


Wow, that graph is fantastic. I know it still took an incredible effort but still I do look forward to OmniPod releasing an aps. Thanks for keeping us inspired!


How are you implementing wat soon w Loop? Lower target?


Yes, I set the workout glucose target to 65 like an hour before I eat, kind of like a super-bolus. I think of it like “stepping on the gas,” to deliver more insulin. My use of this function around eating is opposite to the programmed intention, setting a higher goal to exercise. My normal target is from 80-90. I like that you can set for one hour, two hours, or indefinitely. The one and two hour selections just timeout when they’re done so you don’t have to remember to toggle them off.


I just updated Caleb’s options to include 3 and 4 hours as well.

When you say “super bolus” you mean something like - an extra strong bolus - yes? Or are you achieving John Walsh’s super bolus bc you are front loading insulin that’s later turned off?


As you know, a super-bolus borrows some basal insulin from the post meal hours, delivers it with the meal bolus, and then pays it back with a temp bolus zero period following the meal. When I set a temporary lower target I induce Loop to be more aggressive with its temp basals (both higher high temps and less low low temps). If it works as intended then Loop will back off the high temp basals during the after meal time and essentially “pay back” the borrowed insulin from earlier.

The beauty of the super-bolus is that the net effect on insulin dose is zero, just the timing is changed. I think this tactic works similarly. By the way, I see this technique as a crutch and I think better fundamental Loop settings are the real answer. But it works so well, I find it a nice work-around while I figure out a better answer.


Yes, yes. We’ve been super-blousing for a long, long time. I just wanted to be sure I understood your use of the term. Loop does inherently super-bolus quite a bit. I wish it did it a little more aggressively, tbh.


When you are trying to super-bolus by setting a lower target, @Terry4, how long do you set workout mode to be on?

I was attempting to achieve this by changing Caleb’s target from 5:30 and 7:30 - he eats around 6:30. It’s not working bc Loop is forecasting a bg in range at the end of his DIA which extends beyond the time I actually want the lower target. It seems the only way to achieve it is my using indefinitely, and then turning it off. Or am I missing something?


When you set a workout target for say 2 hours, Loop considers those new targets for all calculations over the next 2 hours. The bg value at DIA is compared to these workout targets -
it does not matter that DIA is extending beyond 2 hours. I am not sure why this was not working as intended - maybe Loop predicted eventual bg at DIA inside the workout targets? If so, then it really should not be high temping anyway.


Thank you, Dragan. I believe Loop predicted a bg value at DIA which was within the bg target at that time - 9:30 (105-135), but was higher than the range set for 5:30-7:30 (70-90). His bg was 122 and Loop was predicting he would stay flat for the following four hours. We were not using workout mode. It’s a target I’ve set bc we’re asleep at 5:30. Does that make the difference?


Setting lower targets for 5:30-7:30 can help in the sense of encouraging Loop to high temp some prior to the meal time. However, as you’ve noticed, this won’t affect bolus recommendation or high-temping at 6:30. You may consider turning workout on (with lower but still safe targets) at or before meal time for the next 1 or 2 hours, to encourage more aggressive bolus recommendation and/or more aggressive high temping for the meal.


I’m using the “workout mode” with a lower target around meals and at other times when I want to manually encourage more insulin delivery. I use one or two hours as the duration but will turn it off early if I see a falling trend.

This morning, for example, I woke up around 60 but could see that I had not been in hypo territory for more than 20 minutes or so. For a few weeks my morning pattern was to wake up in the low end of my range, 70-99, and my BG would first head slightly lower, then over the next 30 minutes or so head higher. I’ve referred to this secondary rise and attendant insulin need as my “feet hit the floor” morning insulin requirement.

I’ve been eating one half to one full glucose tab to treat the half-hearted low and when the BG starts to ramp up, I’ll use the workout mode with a lower target (I use 65) to mitigate that rise. Here’s this morning’s trace.

I ate one glucose tab just before 8 a.m. and then turned on the workout mode, 65 target, for one hour, starting at 8:30 a.m. when the line started to rise. I was able to stop that rise at 100. Without this tactic, I know I would have gone to the 130-140 range.

I normally eat a late breakfast, around 11 a.m. Around 10 a.m. I’ll turn on the workout mode lower target and set it for two hours. This helps blunt my post meal rise to the 120 range, instead of the 140 range.


That is my goal. We are not achieving it, which I thought was bc the bg at DIA is within target at that time and no consideration was being given to the lower target prior to DIA. I’m still not clear that that is not the case.

I had not considered that the bolus would be impacted. He’s not bolusing until after he wakes up. My goal is to get active insulin in him before he wakes up. I thought the bolus would be for the meal and that was that. I’m not sure how targets play a role in that.

@Terry4 - In your example it’s just after 10am and your dia bg is 74, yes? I don’t understand why Loop is not giving a temp basal reduction to get the dia bg in range. That’s what we think we are seeing - if the lower target is not as far out at the dia bg, then it will not consider that in the temp basal.


oh, now I think I understand what you are trying to do: you want to automate “eating soon” technique, so that he has some insulin going before he wakes up for the breakfast at 6:30? Yes, you are correct. If you set a lower target for 5:30-7:30, Loop should have already high temped earlier during the night, starting DIA before 5:30, which is too early. I think there are 2 ways to accomplish your goal of having some high tempting start, for example 1 hour before 6:30, so at 5:30: one option would be to set a lower target from (5:30+DIA) to (5:30+DIA+2). Another option (assuming you’ve upgraded to Loop 1.3.2dev) would be to enter some future carbs at (5:30+DIA) the day after before you go to sleep. Either of these two options should encourage Loop to start high temping at 5:30 for the upcoming meal at 6:30. Hope this makes sense? BTW, thanks for the idea - I may give this a try :slight_smile:


Right! Not only am I not achieving what I want, but I’m creating another problem with this change in target. [quote=“Dragan1, post:236, topic:57501”]
Another option (assuming you’ve upgraded to Loop 1.3.2dev) would be to enter some future carbs at (5:30+DIA) the day after before you go to sleep.

This is fascinating. Yes, we have 1.3.2. Caleb has mentioned the ability to enter future carbs. I thought he was nuts. When you say enter at 5:30 + DIA, does the + DIA refer to carb absorption?


No, DIA = duration of insulin action. I’ll describe an example, which I will try tomorrow, and will let you know how it goes. Lets say your DIA = 4 hours. The night before you go to sleep enter future carbs (a small amount, be careful) at 5:30+DIA = 5:30+4 = 9:30am tomorrow morning. Select carb absorption for that meal the same as you would do for the anticipated breakfast. Since Loop is looking at bg prediction DIA ahead, at 5:30am it will see bg increase coming up and will start high temping. As a result, at breakfast time at 6:30am there should already be some extra insulin going. At that time, touch on the carbs graph and edit that previously entered meal: change the time to current time (6:30), and change carbs to whatever the breakfast actually is, and accept whatever bolus Loop recommends. Please be cautious and careful - what I’ve described above is a bit unconventional. Will let you know if I confirm this approach works.

Time to let Caleb take over? :wink: (btw, during the day, I enter future carbs very often as a way of pre-bolusing with Loop)


Wow. This is some creative thinking. I thought you meant to schedule the carbs at 5:30 w a ca the length of día. You’re suggesting schedule the carbs for 9:30. I get it. I like it.

Rather than change the target, Caleb has been inputting some carbs a half an hour or so before he eats to get the temp basal increase. That seems more effective for him. This forecasting of carbs had not, and probably would not have, occurred to me. [quote=“Dragan1, post:238, topic:57501”]
Time to let Caleb take over? :wink:

Indeed. That’s what we’re working toward. I love when he comes up w this stuff. I need to pay more attention to him. :slight_smile:


Yup, that’s exactly what I am doing routinely, and it’s working well for me too. I find such high temping safer and more effective than traditional pre-bolusing or changing the target (although changing the target is admittedly even safer). In any case, looks like Caleb is going pro with Loop - that’s great! :thumbsup:


Thank-you to @Lorraine and @Dragan1 for an interesting discussion raising tactics I had not yet considered. It makes me realize that there’s much more to Loop than meets the eye. Here I am at six months in and still learning. And I’m enjoying the best control of my diabetic life.

Lorraine, Caleb’s interest in this project tells me that you and he are on the same side in the fight against diabetes. That is no mean feat in rearing a teenager!


Do you have a rule to determine how many carbs to input in advance? A fixed amount, percentage, just your gut?

I’m lucky. He’s a good kid and an over achiever even when it comes to diabetes. He has never missed a meal bolus, ever. He’s also highly motivated because of this trip to Italy he applied for, was awarded and he really really wants to attend.