DIY Looping

Steve and I had the pleasure of going to Vienna, Austria together two weeks ago for the diabetes technology meeting, and while there definitely was some cool stuff presented in the artificial pancreas world, my update comes from my own AP world.

As I’ve mentioned before, I started on LOOP about 4 months ago, and I think I’m finally ready to give an update on it.  So first off, what is LOOP?  Basically, it’s an AP system that uses:

  1. An old Medtronic pump
  2. An Iphone
  3. Your CGM (Dexcom or Medtronic)
  4. And a device called a “RileyLink” that connects them all together

The founder of Loop has a daughter with T1D named Riley, and thus, RileyLink!

So what does it do?  Basically, it uses an app to determine what basal rate adjustments should be made on your pump, and uses the RileyLink to hack the pump and tell it what to do.  You still have to bolus as you would for meals, and correct, and all that garbage, but the system does a great job of giving you more or less insulin as a basal rate.  Basically, it does what the 670g system does, but with a lot less hassle.  So what do I like about it?  Well here it is:



I could probably just drop the mic after this one and walk away and I would be fine with that.  I simply don’t get low at night anymore.  And I don’t really get high either.  Nighttime went from my most frustrating time, to my most consistent.  My wife told me the other day, “Hey you don’t sleep with apple juice by your bed anymore.”  And I was like- she’s right.  Now I’m just spending time thinking about what I’m going to do with all this juice money.  Seriously though, I don’t wake up to alarms, and I wake up every day with a really, really good blood sugar.  It took going on LOOP to realize how crappy I was sleeping before…  Low.  Eat.  High.  Insulin.  Repeat.


Yeah that’s right.  Loop lets me slack off a little, and I kinda like that.  I know if I don’t nail my bolus, the basal rate will kick in to help minimize the damage of me drastically underestimating my carbs…. again.  So I think I worry a little less about the fluctuations and my time in range is better.


Not a lot to add here.  I get low less.  Less at night, less during the day, and less with exercise.  Less lows means fewer texts from Steve telling me to get my shit together.  I really like that feature a great deal.


The pump is completely controlled from your phone through a pretty slick-looking app.  So if you don’t want to, you never really have to touch your pump.  You can adjust your target to whatever you want- including an exercise target.  It gives you a predicted glucose curve and its fun to see it shift when you enter carbs or insulin.  It’s not always right, but it looks cool.  You can tell the app if you’re eating a high carb meal (lolly pop), a mixed meal (taco), or high fat (pizza).  All well thought out stuff.


So what don’t I like about it?  Well it’s really when it just doesn’t work.  Sometimes it drops the Dexcom signal or isn’t picking up the pump for some reason.  So I do spend a fair amount of time looking at the app to make sure I’m still “looping”.  Carrying the RileyLink around is kinda annoying and I’ve broken 3 of them.  Yes 3.  All water related.  So more “fried” them then broke them.  But this is all minor stuff.


How do you or your patients get on the system?  To be honest it’s a little complicated to set up, but I actually did it myself (the second time) without any problems.  There are VERY good instructions here:

I didn’t mention before that this is a complete Do It Yourself (DIY) system so is NOT FDA APPROVED, you won’t find it in any CVS, and your doctor can’t prescribe it for you.  You have to do it your damn self (DIYDS).  And to do that you’ll need all those things I mentioned at the top, several hours to spend, and about 130 bucks to buy a RileyLink.

I didn’t realize how much LOOP had really been helping me until I was in Vienna, and I only packed one European electrical converter and ended up charging my phone more than my RileyLink.  So my LOOP would drop out when the RileyLink didn’t charge, and I was back to the dark ages.  Champagne problems for sure, but hey, it made me realize what a big advance this type of technology is.  So while we are waiting for systems to get better and better, for now, go out and DIYDS.


This post originally appeared on If you are a diabetes professional and also have type 1,  sign up for the WeAreOne online diabetes community here!

  1. Avatar

    Hi Jeremy. Nice to hear good news and the closed loop concept is brilliant. I have the feeling that increases weight gain. How is your weight going? Regards from Lisbon, Portugal

    • Avatar

      I would imagine that any weight gained would possibly be a byproduct of better controlled diabetes: remember, insulin=growth and storage hormone. HOWEVER: remember all those lows he’s not treating??? Each low treatment is about 60 calories (if you’re following the “rule of 15’s), not to mention rebound problems….therefore the eating that someone looping is doing is likely going to better reflect what that person would do even without diabetes (disregarding the action of amylin…but that’s another story for another day). I think that most people looping or using 670g actually would have the opportunity to LOSE weight easier….

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    Hi Dr. P: Great presentation of DIYDS ! I am using the 670G and have been T1D for many years and 4 Medtronic pumps and the “dark ages”. The first quarter on the 670G resulted in an A1c drop of 1.1%, 12 lbs weight loss, and in-range 94% of the time. It also results in a loss of sleep, blood, and lots of test strips. BUT IT WORKS !!! I hope Medtronic is working on doing a field-upgradeable software package for some of it’s quirks (no public specifics).
    I have an old Medtronic Paradigm pump. I may try this in parallel with the 670G. What sensors and transmitter did you use with the Riley ? What is your finger stick sensor calibration frequency ? Does this “system” have a separate rendition of/like the 670G Auto Mode for Basil, and a calibration procedure ? I am an Android phone guy; is there an App in the near future or will we continue to be discriminated against like the Diabetic Industry does ? I’m looking forward to your reply……..R

    • Avatar

      Hi, my husband has been looping for 3 months now and has lost about 3-4 kgs. it has radically changed his life after being type 1 for 44 years. No night time hypos and waking up in range everyday. And I sleep all night too, awesome !!!

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    Is there anyway to rig a tandem t slim pump? I wanna LOOP too!!!!

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    Hi Jeremy,

    We met at the TCOYD conference in St. Louis last year just as you were getting set up with Loop. I was on one of the panels you moderated. I’m so glad to hear that it’s going well for you and I 100% agree with what you’ve found re:sleep being the biggest benefit. Cheers!

  5. Avatar

    Sorry for my delayed response, I was looking on WeAreOne for comments and not here, so here are my thoughts

    1. Weight- my weight went up a little bit because I think im probably taking slightly more insulin than I was previously. Hard to say for sure though since I made a lot of changes. I went from basal insulin and afrezza to Looping, so the weight gain was probably just from going on to a pump rather than LOOP itself. Afrezza has shown to result in some weight LOSS, so I might have just lost that benefit. I WILL say, however, that LOOP makes it easier to eat carbs etc so you have to keep an eye on your intake for sure.

    2. It doesnt work with Tandem yet. Sorry dont shoot the messenger. BTW they should have it ready to go with the Dexcom G6 very soon now that it has been approved.

    3. Bert thanks for the post. You were my inspiration!!!!

    Take care everybody


  6. Avatar

    Thank you Jeremy! I’ve been T1 for 32 years now and am currently using the 670g + Guardian Sensor. My experience is that it works great as long as the infusion site connection is good. That’s the major issue for me as someone with a fairly low-fat mass. The statement you made that most intrigued me was this: “Basically, it does what the 670g system does, but with a lot less hassle.” What do you find is easier about looping than using the 670g system? Aggain, thanks so much for the report back!

    • HI! I like that Loop NEVER kicks you out of auto mode. AND you can use the G6 Dexcom which is a better sensor and doesn’t require calibrations. So you don’t have to do all those tests, and always stay in auto mode, and can do it all from your cell phone. Less hassle! 🙂

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    Jeremy, Seeing that you are in the community, have you asked Dexcom to work directly with the Loop Developers to resolve the connection issues you experienced? How about working with Tandem or others to allow for the use of Loop. I see this as an opportunity to give an opensource community the ability to test drive the latest hardware with the latest opensource software and use that data for trail guidance. If your a manufacturer seeking FDA approvals and need to conduct a trial, wouldn’t it be nice to already know the outcome of that double blind cohort study? What if you already had the results from 50,000 people who had been “experimenting ” with it in the open source community ?

    Maybe I’m a bit to naive, or to visionary, though I think in the competitive landscape for diatech, any advantage is $$$. From what I can tell, medtronic want’s no part in the opensource space and as a leader, is toxic to innovation. Thus, closing access to next gen devices and removing access by way of firmware updates to older devices. They could allow user to reload older firmware’s by choice the way Apple still does.

    On the other end of the spectrum Tandem is a newcomer with nothing to lose and insult has some interesting tech. I think if Dexom (Best Sensor in the industry) bought Insulet and integrated its sensor, and at the same time open sourced the platform and supported it in the opensource community (like Google does with kubernettes), they would corner the market and could leverage loop and other communities to advance tech in this space. Tandem could benefit from this move as well as they are already partnered with Dexcom and could provide the more traditional path.

    So, if you every get a chance to speak with a product owner at one these companies, let em know this crazy guy had these crazy idea’s..

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    I am a little late to the Looping party. I am on the 670G with a guardian sensor and became curious about the looping from an article i read yesterday. My main question is abut the phone, is there any known development in making this work with android phones?

    • Avatar

      Same question and hope here for Android.
      I’m happy to throw some money at helping to get an android development done

    • Hi Seth,
      We haven’t heard of any yet, but we’re sure people are working on it because of the high demand.

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    What type of pump and sensor are you using in your loop?

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    Hi, Can medtronic guardian sensor and omnipod compatible with Loop?
    Some say they’re not compatible. Thank you.

  11. Avatar

    Does this work with tandem pump

  12. hello
    my son has ASD and Type 1 and is now on a medtronic loop system ( sensor and 670g)
    till now we have been able to get alerts on our phones using the dexcom sensor……
    now we have change to medtronic does anyone know if its possible to get a readout/alerts to my phone still.
    Medtronics says “officially ” NO??

    • The best system for your son is the Tandem Control-IQ that communicates with the Dexcom G6. The Dexcom G6 does allow sharing in real time, whereas the Medtronic sensor does not. I suggest you use everything in your power to appeal so you can use the Dexcom and Control-IQ system. Medtronic’s new system will have this capability, but not sure when it will be coming out.

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    This is the first time I’ve heard about DIY looping, but I’m currently using the Tandem X2 with the Dexcom G6. Can you tell me if there are any advantages to DIY looping over using the X2 with the G6? I feel like my current regimen is working for me, but just wondering if I can do better!

    • The only reason to switch would be if you’re tired of the tubing, but other than that it’s really not worth switching.

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