How to loop in diabetes – Build a closed loop system that works

*Disclaimer: All content and information in this blog is for informational and educational purposes only.
This article was written by Pete Lomas (T1D) and medically reviewed by Rachael Baker, BNg, CDE, MNgPrac
Last updated on 01/02/24.

Have you ever heard of the ideas “Loop in diabetes” or “DIY Looping” ? ‘I’m not a “Looper” but I am super proud that our T1D community has individuals smart, brave and ingenious enough to be pushing the boundaries of medical technology to make their lives and their diabetes more manageable.  I think it’s so cool that this community exists to support each other with very little vested interest other than helping out a Diabuddy!

#wearenotwaiting is the mantra and it pretty much says it all.

This Looping community is not waiting for the powers that be to commercialize and regulate technology that helps them create closed loop systems/algorithms that use CGM data to message insulin pumps and deliver insulin without the need for manual CGM data entry.

What is looping? 

Looping originated when Dana Lewis stumbled upon a tweet from John Costik about his ability to access his son’s CGM data remotely.  John shared his code enabling Dana to upload her CGM data to the cloud.  Throw Ben West in the mix, who had reverse engineered insulin pump communication protocols and you have CGM data algorithms that predict glucose levels and the ability to leverage this data to influence insulin pump activity.   

So on a looping system, the collection of CGM data, previous insulin dosing, food intake and blood glucose values allows insulin dosing commands to the pump to regulate insulin dosing and bring glucose levels back in range.  

The equipment you need for DIY Looping

1. A computer to hold the algorithm
2. Radio stick to communicate the algorithm to the pump from the computer
3. Insulin Pump
4. Continuous Glucose Monitor
5. Smart phone to access the app
6. Bravery, ingenuity and some IT savviness 

The closest commercialized looping option is the Medtronic 670G “hybrid closed loop” system which automates basal insulin but still requires button pressing and bolusing for carbohydrate consumption. 

How do you build your own closed loop system 

This one is a little more tricky and there isn’t much out in the ether about building your own closed loop system, unless you want to convert your Freestyle Libre, which is technically a flash monitor as opposed to a continuous monitor (CGM).  There are three options on the market to convert the Libre into a ‘continuous’ monitor. The Ambrosia NightRider, the MiaoMiao and the Bubble.  These Libre attachments facilitate continuous messaging effectively enabling you to build your own CGM. 

Can you loop in diabetes with Dexcom, Freestyle Libre, Omnipod or other devices?

Currently  Dexcom G4, G5, G6, xDrip+ and Medtronic CGM’s can be part of the lopping set up and Omnipod insulin pump is also being ‘hacked’ by loopers now.  Insulet has promised to bring a closed loop system to the market with Omnipod 5.  Their CEO (Shacey Petrovic) has even acknowledged the Looping community, which is a milestone of sorts as to date “industry” have tried to ignore looping and hope it goes away.  Stacey’s acknowledgement is smart on her behalf and looping is here and the community are highly engaged and pretending looping will go away is hoping to ignore a key element of the diabetes community.   

There seems to be less information in the ether about Freestyle Libre and its role in a looping set up.  This fits somewhat with the marketing of the Libre which is more mass market designed as opposed to niche specialized T1D specific.  This has been a key differentiator with the way Abbott have taken Libre to market and expanded indications to T2D and the fitness market.  CGM’s don’t just belong to people with diabetes anymore and Abbott are at the forefront of opening this up.

Advantages and disadvantages of looping 

Loopers observe improved time in range and decreased A1c.  Some caution is recommended with the real world data that underpins any looping results as we don’t yet have any randomized controlled data.

Aside from the observed clinical outcomes, loopers have also observed improved sleep quality and general quality of life improvements.

The risks with looping are the DIY nature and lack of regulatory control that can result in patient safety.  Looping is ‘experimental’ and this brings inherent risks as outlined by Diabetes Australia.  DA does not endorse DIY / Looping per se but does acknowledge the gap between approved technology and a market need.

My personal viewpoint

Personal responsibility is the winner here.  In a world increasingly restricted by regulations and the ever increasing reduction in personal responsibility by laws and regulations , I am wholeheartedly in favor of the looping community and the #wearenotwaiting movement.  Know the risks, do your research and decide for yourself if you have the tech savviness and the wherewithal to become a looper.  There’s plenty of support online and the looping community is one you can rely on for support.