Closing the loop – The System that’s Changing Diabetes Management


Life is full of disappointments. I mean I don’t remember 4-year-old me getting that Christmas pony I was promised. But when you’re talking about life with type 1 diabetes, disappointment takes on a whole knew meaning and order of magnitude. A1Cs (both low and high), all-nighters because of blood glucose levels (BGs), , and those are just a few of the ones that start with the letter B! In short, the type 1 community is no stranger to disappointment and this past year has proven to be no different.

With announcements of the intended discontinuation of insulin pump delivery systems by Johnson & Johnson’s Diabetes Care Company in October and Roche Diabetes Care Company in January, it would seem that 2017 could be in the running for a spot in the Type 1 Disappointment Hall of Fame. But while this past year has added onto the all too familiar pile of disappointments, hope still remains as the next phase of type 1 management makes its way into the mainstream.  

Closed Loop Insulin Delivery: a system that works to mimic the human pancreas by using real time continuous glucose monitor (CGM) data to determine when it should or shouldn’t make adjustments to the wearers basal insulin delivery. It is a concept that has been around since the early 2000s but which has seen its greatest strides towards actuality in the past two years.

In 2016, five different medical device companies announced the release of their versions of a closed loop insulin system within the next two years and one, the Medtronic’s MiniMed 670G system, already hitting the market this past Spring. Trial studies have shown closed loop therapy benefits range from fewer experiences of extreme highs or lows to improved A1C results and even better sleep due to greater BG stability throughout the night. And in addition to these industry produced closed loop systems, many in the type 1 community have taken matters into their own hands and developed their own do-it-yourself closed loop systems utilizing altered or hacked technologies that are already being used.

DIY closed loop systems have been in use by a growing subset of the type 1 community. For years now proponents of DIY systems have been working together and utilizing computer programming skills to hack current devices and technologies to effectively achieve a “substitute pancreas” that requires less human involvement. This then provides those interested in the benefits of closed loop therapy and bypasses the strict standards and guidelines medical device companies are held to by the government. For all the Batman fans in the room, it’s like the difference between the Dark Knight himself and Gotham PD.

Both are basically trying to keep the public safe but have different tools at their disposal. In the case of medical device companies like Medtronic or Tandem, they are held to specific legal standards and guidelines intended to keep the consumer safe. Those who have discovered DIY closed loop systems, on the other hand, can use their technical knowledge while also not being hampered by the same legal constraints allows them to use existing technologies in new and unintended ways. While both can result in a functioning closed loop system and all the benefits thereof, both also suffer from unique drawbacks: getting government approval for medical devices can be a very drawn-out and expensive process that can often times takes years and capital that a select few companies have access too. DIY closed loop systems require a certain level of proficiency in skills like computer programming or engineering, skills that your typical person with type 1 diabetes just doesn’t have which then limits their ability to take advantage of DIY closed loop systems.

While in the wake of losing three different insulin pump systems this year, the type 1 community still has much to look forward to. The options may have been taken from us but more are coming soon as has generally been the case in the type 1 world. Lending credence to the adage that I just made up, “When one medical device company closes its doors; another opens theirs.”

Read an interview with Melissa who is a DIY looper.

WRITTEN BY Walt Drennan, POSTED 03/20/18, UPDATED 10/23/22

Walt was diagnosed with type 1 diabetes in 2000 at the age of 12. Despite having type 1 diabetes (T1D) for over half his life Walt didn’t really come to terms with it until after completing a cross country charity cycling tour in 2012. Cycling over 4,000 miles from South Carolina to California in 80 days with no type 1 complications made Walter realize that the only thing hiding him back from doing everything he wanted was himself. He’s been cycling ever since and completed a second cross-country charity cycling tour from Maryland to Oregon in 2014. In 2017, he was Bike Beyond's program coordinator and crossed the US for a third time from New York City to San Francisco.