Conversation with a DIY Looper, What It Is, and Why People Do It

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By : Suvarna Sheth

There is a growing group of people with diabetes that are taking things into their own hands: Instead of relying on expensive glucose management tools made by large manufacturers, they are opting to build their own.

The devices are essentially hacks of two diabetes management devices that people have figured out ways to work together: continuous glucose monitors (CGM) and insulin pumps, essentially creating a do-it-yourself artificial pancreas device.

The CGM gathers information, when a person’s glucose levels are high, and instructs the pump to deliver insulin. The DIYers often build their own devices by following step-by-step instructions found on the Internet.

They make the two devices “talk to each other,” by doing what’s known as “Closing the Loop.”

A Bloomberg article reported last year that by some estimates as many as 2,000 people around the world have used a home-built pancreas made mostly by users on social media sites and GitHub, a site where developers collaborate on code and build their own software.

DIY Choices For Diabetes Management

There are a few options for creating a closed loop, from OpenAPS to Looping, to AndroidAPS- and each has their respective followers.

OpenAPS – or “open source artificial pancreas technology” is a system made out of a miniature computer and radio. It works with older Medtronic pumps and any CGM. It can be set up using a PC running Windows or Linux, or a Mac.

The growing community of OpenAPS DIYers can be found using the hashtag: #OpenAPS hashtag on Twitter.

Loop – a system that is compatible only with Apple and runs on an iPhone. This system also uses the older Medtronic Pumps, uses Dexcom Share or G5, or Medtronic CGM for glucose data. It also needs a “RileyLink” to communicate between the pump and phone. It requires xCode on a Mac to set up and costs $99 for an Apple developer license.

AndroidAPS – This is an option for Android users and uses the OpenAPS algorithm. It works with a DANA*RS & Roche Combo – the first closed loop implementation on Android. It works with multiple CGM systems and requires Android Studio to set up on either a Mac or PC.

Conversation With A DIY Looper

To get a personal insight into looping technology, dLife speaks with DIY-looper, Julia Blanchette Ph.D. (c), RN, CDE, to learn more about the DIY community, what is it, and why she is a part of it.

1. Can you describe what exactly your looping entails?

Loop uses specific, older Medtronic pumps, or the Eros version of Omnipod pods, in conjunction with a piece of hardware called RileyLink, Dexcom G4/5/6 and an iPhone app you create called Loop.

I use the Omnipods and Dexcom G6. RileyLink and the phone must remain close to the pod (or pump) and CGM at all times.

After programming the application and putting it on my phone, I entered my baseline basal rates, insulin to carbohydrate ratios, target blood glucose ranges, insulin sensitivities, and maximum basal delivery.

As I changed from a different pump system, I wasn’t sure these settings were correct, so I started conservatively and reviewed my patterns to make adjustments.

When eating a meal, I enter in my estimated carbohydrate amount and absorption rate. The app provides a bolus recommendation and you can deliver that amount, override or underride it.

Then, Loop predicts future blood glucose (for six hours into the future) based on the entered settings, carbohydrates on board and insulin on board.

The Loop app adjusts insulin delivery using a temporary basal rate to reach the target blood glucose. If the target blood glucose is predicted to drop below your pre-set target range, the basal insulin will decrease and will increase if predicted to rise above the target range.

If the sensor glucose reading (CGM reading) is below the pre-set suspend threshold, delivery is automatically suspended and resumes automatically once above the threshold. As with any insulin pump, you have to refill the insulin and change the infusion set every 2-3 days. You also have to change the CGM sensor as indicated.

2. What is the greatest need within the DIY-community? Why do people resort to DIY looping?

The greatest need within this community is having provider support. As this is a DIY system, there are no certified insulin pump trainers or CDEs who can help walk their patients through benefits to choosing the system, realistic expectations of the system, setting up the system or helping with pattern management after starting the system.

There is a lot that has to be done before having greater provider understanding and involvement, and provider support would establish greater safety and optimization in using the system.

There is also a gap in understanding how the algorithm works and how to properly adjust one’s settings in the Loop app, which is problematic without the help of CDEs and providers.

There are wonderful documents called LoopDocs which walk one through setting up the system, tips before starting such as basal testing and safety tips.

These docs are so helpful and I highly suggest anyone Looping read them before jumping in. But, one also has to understand the benefits and limitations of using the insulin pump and CGM system of choice.

Regarding the second question, people resort to Looping because it provides greater flexibility and precision to achieve optimal glycemic control while reducing user self-management burden. There is no product on the market right now that is able to relieve the same self-management decision burden as Loop.

3. You have a unique perspective, as a CDE. Why did you choose to DIY loop?

Before choosing DIY-Loop, I used a wonderful system that I had few problems with. I had a great time in range and my HbA1c was also at my goal.

However, I had to put a lot of work into it. I did a lot of sugar surfing, extended boluses, and temp basals. I reviewed my patterns and made insulin setting and/or basal adjustments at least once a week.

I had always been curious about Loop. I was curious since I heard about it a few years ago but too scared to try it with an out of warranty Medtronic pump. So, I had been following the DIY Loop community in anticipation of the Omnipod Loop release.

When I heard that Omnipod Loop went public, I jumped right on it. I used Omnipod previously and I understand the pump system itself very well. Plus, Omnipod is accessible to me.

My friend, who is a software engineer, helped me set up the system quickly. It took about a week to figure out my settings– when switching pump systems you may have differing insulin settings due to different mechanisms of insulin delivery, in addition to figuring out the proper settings for Loop.

I was happy I stuck it out because my time in range has increased to about 90%! I no longer have to focus on sugar surfing after meals and making so many adjustments, although I do review my patterns.

I feel Loop is able to improve my quality of life- it relieves some of the constant burdens of using my self-management decision making and skills. It also reduces anxiety when I go to bed at night. I no longer have to worry about waking up high or low.

4. Has it ever crossed your mind whether DIY looping is safe?

The only time the safety of Loop has crossed my mind is when other healthcare providers ask me about it. I wouldn’t intentionally place myself in danger by starting myself on a system I felt was dangerous. In fact, I feel safer Looping since it keeps my blood glucose more in range.

However, since starting Loop, I now have a different perspective regarding safety. I see many individuals who are curious about the system or begin using the system without being properly prepared or fully understanding the system.

I do not see the algorithm itself as dangerous. I see user error such as putting in incorrect or settings that are too aggressive, or not having a back-up plan in place, as dangerous.

5. What are your thoughts on the FDA’s recent warning against using DIY diabetes devices? 

As my friend Nick Galloway, who is also a CDE with Type 1 diabetes says, “Reality is diabetes is a constant DIY. People still get hurt with approved therapies every day.”

The truth is that diabetes self-management is never going to be perfect. Insulin itself is a dangerous but life-sustaining medication and insulin pumps themselves place users at a higher risk for DKA.

People who are insulin dependent constantly take chances and try new strategies when making daily self-management decisions.

The blame cannot simply be put on the device or the algorithm, especially when we don’t know the circumstances that led up to the event of severe hypoglycemia. Did the device actually “overdeliver insulin” or was it programmed to deliver too much insulin based on the wrong settings, circumstances or inaccurate information?

Would the event have more easily occurred if using a different device or MDI? You cannot make the conclusion that the device alone over-delivered insulin without understanding the full picture.

In a way though, the FDA is correct. As this is a DIY system, it has not gone through typical FDA trials so scientific evidence is lacking regarding the safety of the device. Providers may hear stories or see patients who have great success on the device, but the scientific support for safely prescribing the device is currently missing. Providers cannot feel safe prescribing the device if the risks associated with it are unknown- that is a huge liability.

While we wait for Tidepool Loop and future automated insulin delivery systems that will go through FDA approval, I highly recommend that anyone who uses Loop considers joining the Jaeb Loop study. The study sends out email surveys weekly in which acute complications such as severe hypoglycemia or DKA can be reported by those who use Loop. Providing evidence that Loop IS safe, but also reporting issues, is key right now!

6. What age would you consider Looping safe?

The answer is complicated—age isn’t as big of a safety consideration as having the right daily insulin requirements for Omnipod and understanding the system.

The issue with Omnipod is that it isn’t able to give as precise insulin doses as the other systems. Omnipod delivers insulin in .05 increments and cannot set a 0.0 unit/hr programmed basal rate. If the child isn’t on enough insulin per day to use the Omnipod, that would be a barrier.

Also, the RileyLink hardware component of the system isn’t waterproof, but Loopers have found water-proofing solutions which could be used for younger children.

For children who have large enough daily insulin requirements to use Omnipod, it really depends on the caregiver’s understanding of Loop. If the caregiver understands Loop, then Loop would be generally safe to use- just like with other insulin pump systems.

Additionally, if the child is starting to take on independent self-management tasks, the phone app which controls the system is easy to use. In fact, I think Looping would make self-management easier during the tricky teenage years. The system does more work than I would expect teenagers to put into self-management.

The part of the system that could be unsafe is if one does not understand how it works or how to make adjustments as discussed earlier. Many adults do not understand pattern management regardless of Looping.

7. Any other thoughts you’d like to share?

I would just like to reiterate, regarding providers, there is the total reason for concern if patients do not know how to pattern manage or fully read and understand Loop docs before using the system.

The biggest point I would like to make though is that the quality of life benefit that Loop provides is amazing. It is important to understand and respect why one chooses to Loop. Loop offers what other insulin delivery systems do not.