DIY looping, can I trust it?

T1D Jonathan Garfinkle writes in The Walrus blog an interesting account of how he came to use Loop, an automated insulin dosing system. The history of the #WeAreNotWaiting open-source community is woven into his personal diabetes story.

Jonathan was diagnosed over 30 years ago at 12 years of age during a family European vacation. He writes about a poignant memory of the moment he realizes what this means to his life.

I have cried only once before because of my disease. It was my second day in that London hospital, and I was learning how to inject insulin by practising on an orange. It was the moment I understood that diabetes is a life sentence. My mother was outside my hospital room, and at first, I wasn’t sure what she was doing alone in the hallway. It was the first time I saw her break down too.

He comes to this story with a healthy dose of skepticism and that makes his narrative compelling and credible. Enjoy.


It’s a great account, very informative—thanks!

And as always with these things where someone is describing their D experience over a similar timeline to my own, my attention gets snagged by largely irrelevant discrepancies between their experience and mine. They don’t detract from the main points being made, but I just find myself going “Wait—what?” and “When was this written?” to these things when they pop up. Like:

“Artificial pancreas” isn’t a term I’d heard before. I ask Riddell to explain.

Wait, when was this written? Guy seems pretty D savvy, but this term has been around for a decade maybe? Also surprised that he appears to have been totally unfamiliar with the DIY looping community before writing the article. Which is actually not a bad perspective to start from when writing for the general public. But it did make me realize that the only reason I’m familiar with this stuff is because of TUD and contributions by people like @Terry4. So stop assuming we all have the same knowledge base, I tell myself.

Another was where he describes being given the line at DX in 1986 about “You can eat what you want as long as you dose for it,” which I thought of as being entirely contingent on the advent of Lantus/Novolog basal-bolus MDI and 86 was back in the R/N era. I was dx’d in 83 and I sure as heck didn’t hear anything of the kind until the late 90s. For me it was all eat-to-the-insulin up to that point, and the whole carb-counting, I:C ratio stuff was totally not a thing, though it was a life-changing development when it did finally come along.

On the eye-opening side, I had no idea that the @We’reNotWaiting movement started over getting the Dexcom G4 to talk to a smart phone at all, not about using it to control delivery from the pump, though it was a necessary step in that direction. I love learning about this bit of history.

CGM in the Cloud, an international community of 30,000 members with a do-it-yourself ethos, all of whom were interested in hacking existing devices to find new ways to manage the disease. Like Farnsworth, members felt that official health channels, with their long regulatory delays, weren’t always working in the best interests of diabetics. They created a hashtag to rally around: #WeAreNotWaiting.

Great article!

1 Like

I was diagnosed within a year or two of you. I think what might explain the disparity of the author’s knowledge of diabetes treatment trends compared to ours was his younger age at diagnosis. He went through the '90’s as a teenager.

I’ve read many accounts of childhood diagnosis, good early glucose control under the watchful eye of a parent and then deteriorating management through the teen years and into the 20’s.

I remember starting on Humalog when it first came out in '96 and I believe a lot of the carb up, shoot up ethos was popular during that time. I think the health care professionals were so tired of the eat to the dictates of your insulin, especially the notorious NPH, that they were more than ready to embrace a different strategy. I think it permitted them an avenue to make a better connection with their patients.

Since I was a long-term pumper, I didn’t use any of the newer basal insulins as they came out. It appears that Lantus debuted in 2000 in Europe, not sure when it became available here.

Yeah, not everyone monitors diabetes management tactics and interacts regularly with their peers like we do. Long before diabetes social media, back in the early '90’s, I was aware of the concept of a CGM and fantasized about using it in the future. I didn’t get a chance to try a CGM until 2009, almost 20 years after I understood the concept.

Not sure when the idea of a closed loop system entered my awareness. I do remember being skeptical of its practicality given the slow action curves of even our “fast” insulins. It took me getting hooked up with Loop to make a believer out of me.

The #WeAreNotWaiting movement was born with the idea to get Dexcom data, G4 at the time, up “into the cloud” so that remote parents, especially, could stay informed of their child’s BG. NIghtscout was written for this purpose. The DIY closed loop idea followed a few years later.

He only cried once. WOW. I lost count of how many times I was overwhelmed by the diagnosis and the reality of what I was facing (back in 1978).

When I went off of the pump a few times, and used Lantus, let me tell you, it can BURN! I’m glad I have no discomfort wearing a pump. Only once have I felt a sting, and that was a 10U bolus with the 670G, using the fast-bolus option.

It wasn’t until I took a pump vacation a few years ago that I tried Tresiba, I’ve never used Lantus but have heard many times about the burning sensation at delivery. I can’t imagine managing a child through that daily discomfort.

I think what is most valuable about these systems is that they can be re-written by the user - ultimate flexibility. Also, the spitting in the face of legal liability. Also, the big data collection for deeper analysis.

Initial results will be released at the end of this month or next month in Spain.

FWIW, my son was only ever on small doses of Lantus (max 5U) as he switched to a pump while still in honeymoon, but he never complained about it stinging.

@Terry4, thanks for the article! The concern many have about this “automatic” type system is always what if the CGM number is wrong!?
It was my very big concern. I am pretty insulin sensitive and my Dexcom G4 wasn’t very on target. I always felt if I bolused off the CGM number and it was off, bad things would happen.
I have been following all these companies trying to put out a closed looped system and have been very excited and very worried. The “what if’s” were brutal.
I dream of a true closed loop, one I don’t have to work at.
So while finding a hackable pump was my downfall, I did find a great substitution in my Tandem IQ.
I have entered another clinical trial and one of the doctors who has been looping for a few years, got to test Tandems new Control IQ and he was so happy with it, he is starting the process to get his own. Big one for him was the loss of phone connectivity. When you lose that with a looping system, there is no system. But he said overnight, he lost the phone connection but the pump was still working as usual.
He did say, it takes some time to get the numbers in a good place but he said within a week, it was rolling!
A week and I can sleep through the night now. I no longer worry about the lows but now I can no longer worry about high alarms waking me up.
And the numbers not being close? Sure sometimes the numbers don’t match. But I have never had any live threatening issues. And when I have tested to check, the CGM comes back into line within an hour. And if I bolus too much, the system has my back and shuts off.
Technology can be so very sweet! And thank goodness for all those DIY’ers! Without them pushing this forward we would not have so many companies working so hard to get this technology out there.
So my personal opinion here, yes I think I can trust it and I do everyday and can’t wait for it get closer to a true closed loop! And just think soon, the Beta Bonics company working on a pump where you don’t have to count carbs, just in out whether it’s a small, regular or larger meal!

2 prereqs: 1) an infallible sensor system and 2) very fast in/out insulin.

Current insulins, injected subq, just last too long to make a true closed loop pump feasible, or safe. My BP goes up a tick every time I see the phrase “closed-loop” mentioned with either the MM or the Tandem pumps. No way are either “close-loop”.

They’re not called a closed loop by either manufacturer. They are in fact labeled by both companies, a “Hybrid” closed loop system, which makes perfect sense considering what they do.

That’s a common sense concern. I only have direct experience with Loop, so I’ll limit my remarks to it. First of all, Loop does not deliver any automatic correction boluses. Correction boluses are all manual with the user taking direct action.

What Loop does do based on CGM data, is set 30-minute temporary basal rates. Loop’s delivery limits are set by each user. If, for example, you take 1.0 units/hour basal rate from 5 a.m. till 9 a.m., you may decide to set 1.5 units/hour as the maximum amount or limit of any temporary basal Loop delivers.

So, if your CGM reading is much higher than your actual BG during this morning time frame, Loop will be limited to only delivering 1.5 units/hour. And doing this as a change to basal rates, the immediate effect will be small.

As a broader thought, I think we as wearers of this tech, need to always pay attention and do a fingerstick if our symptoms don’t match up to what the system is showing us. I understand the allure of a completely automatic system than requires no user monitoring but I don’t think that will come anytime soon.

If the Loop app on my phone loses connection with the pump and CGM, after 30 minutes, Loop steps aside and the pump takes over at its programmed rates. By the way, I don’t often lose connection (the red circle in Loop) for more than 30 minutes, 10 minute disconnects are more common. But these disconnects do not have a large impact on my blood glucose levels.

Good luck with your Control-IQ start. I will be cheering from the sidelines!

Yes, but I see the term “closed loop” applied to them by many people; do you not also see that when reading stories about the pumps?

Yes, but it doesn’t bother me. I believe this is why representatives from both Medtronic and Tandem stress these are Hybrid closed loop systems. I’m with you, eliminating one word in a description makes a big difference.

This sounds exactly like control-iq, sans the 60% correction bolus which still causes me anguish.

I have been jumping back and forth between open and closed loop quite a bit now.
I’m experimenting with that even though my sensor accuracy has been great lately.
I still find it more effective to turn it on and turn it off throughout the day.
In general, lately, I turn it off so I can bolus high before I eat, then 2-4 hours after the meal, I turn it back on to make a nice smooth landing and not go low.

True, they are not a true closed loop system. But they are getting so much closer!
And while, as I stated many times, I was completely wigged about about a CGM making decisions on how much or how little insulin I needed, I have realized for me it is working very, very well! No testing, no worries, no hassles!
And on the few times I have tested and the numbers didn’t match, I just let it sit and it does come back into line. And never once has the system caused me to drop or rise into a dangerous situation.
This really is the first time in my very long diabetes career, that I am not worrying everyday about what is going on.
And now with all the less mental space diabetes has been taking up, I am really thinking about taking up a new language!

Around here, the best bet would be Spanish.

That is my go to choice! My two kids did sign language in high school which is very cool and than my daughter did Italian in college. It came in handy when she studied in Italy but hasn’t used it since. I would like a language I can use everyday.