Life with the DIY Loop

By Christine Fallabel

I’ve lived with type 1 diabetes for the past 20 years, and in that time frame, managing my diabetes has gone from manual finger pricks and twice-daily shots to checking my blood sugar on my iPhone, dosing my insulin from an app, and having my whole basal insulin program adjusted on the fly without me even thinking. 

How is this possible? About a year ago, I started DIY “looping” with my Omnipod tubeless pump and a Dexcom G6. DIY looping basically means hacking your insulin pump with a single-board computer, such a Raspberry Pi or Riley Link, to make it communicate with an existing continuous glucose monitor (CGM) to make basal adjustments accordingly. 

While the community, known as the #WeAreNotWaiting community is small, it is growing rapidly, and people are having better diabetes control than ever before as a result. They have published full instructions on how you can loop too, and people are more than happy to help if needed. Here’s what you need to know about looping, if you’re curious about this tech-savvy way to better manage your blood sugars! 

Setup is Hard, But Not That Hard 

Building the program takes about 3-4 hours. You’ll need to buy a developer account through Apple to set up Xcode, as well as a Mac computer, iPhone, the Riley Link, and currently be on one of the compatible insulin pumps and CGM systems. I don’t code regularly, but it helps to know some of the basics for setting it up. All of the instructions for setup are available online, and there is even a Looped Facebook group for questions and support. 

Note that this system is not FDA approved, and that’s why each individual user must build their own program (to protect against liability). It may be hard to find an endocrinologist who will explicitly recommend their patient trying looping, but few have explicitly advised against it. 

Personalize Management and Improve Quality of Life

Since the user builds the whole program themselves, the user can set their own target bg levels. Mine is set to 110. You can also set exercise targets (I like to workout once I hit 170), pre-meal targets (mine is 80), as well as adjust basal rates for overnight and daytime, and all correction factors. Once you’re set up, you can always change these targets at any time you wish; nothing  is set in stone. 

I’ve noticed the biggest, best improvement in my overnight blood sugar levels. Since this is a hybrid closed-loop system (and not a completely closed-loop, that would be able to administer insulin for food and adjust dosing for exercise automatically), the system does best when there’s less outside interference (i.e. food). It will automatically adjust my basal rates all night long and early morning to accommodate for the dawn phenomenon I struggle with. 

Exercising is also a lot easier with the DIY looping system. When you are planning longer bouts of exercise (long hikes or races, for example), you can set your exercise mode to “on” for a few hours before you start (my exercise bg goal is 170), and the system will make sure you have little IOB before you begin, but that your blood sugar doesn’t soar above your target blood sugar, either. I’ve had much more success with the looping system than my old insulin pump when it comes to avoiding lows while exercising. 

The Most Important Adjustment

When starting the DIY hybrid closed-loop system, the most important adjustment is making sure your correction factor (CF) is appropriate. This is the amount your blood sugar will fall from dosing one unit of insulin.

Turns out that mine was completely wrong when I started, and leading to a lot of lows. Once that was adjusted, it’s been much lot smoother sailing.

It’s also extremely important to appropriately count carbohydrates, as the system does not run on AI and cannot predict your eating patterns or activity level without you explicitly telling the system what you’re about to do or are doing. 

Trouble Spots

The system has been amazing in many ways, but it’s still not perfect, and it definitely is no cure. The system is only as strong as your weakest CGM site, and every time my CGM site errors out, or doesn’t read my blood glucose (at all or even correctly), it throws the whole system off. 

Pump and CGM site changes can also be an obstacle, and due to the 2 hour warm-up window for the CGM, I don’t have CGM readings for 120 minutes on site change day, and my hybrid closed-loop didn’t know how to respond. 

Additionally, you must have the Riley Link near your pump site at all times. Sometimes, this can be an issue with sleep or wardrobe issues. Another (albeit minor) issue is that all of my diabetes care is on my phone now, which is both a blessing and a curse. It’s ideal if you’re trying to lessen your screen time, but incredible nonetheless.

The Takeaway

My hba1c levels have hovered in the 6s for the last 10 or so years, but with the loop I’ve finally been able to achieve an hba1c of 5.9%. The biggest difference is that my time in range has increased from around 30% to 80%, and the number of lows that I experience has gone down from around 3 per day to 1 or 2 per week. 

More than anything, a year into looping has been a blessing for my mental health. I still have to count carbohydrates, adjust for exercise, and dose for meals, but hours can go by where I don’t think about diabetes at all.

I don’t experience diabetes burnout like I used to, and my distress over constantly adjusting my basal rate to avoid highs and lows is almost completely gone. I’m more motivated than ever to continue taking the best care of my diabetes, because I’m not so worn out by its daily management all the time anymore. 

While the DIY looping system is nowhere near a cure, I’m experiencing a more carefree existence, if only ever a little more carefree. An existence where I don’t have to be micromanaging every move I make, every morsel I eat, every minute of my day.

One where my blood sugar is quietly humming along in the background, and not the fog horn in the middle of my afternoon. One where I feel a bit more taken care of, if only ever a little bit.

The cure may not be 5 years out, like the doctor who diagnosed me 20 years ago promised, but with looping I finally feel okay waiting for the cure just a little bit longer. 

– By Christine Fallabel

Sign in or Register to view comments.