New Closed-Loop Pump Options

There are two new options for patients interested in moving to a hybrid closed-loop insulin pump system. Both new options will use the Dexcom G6 continuous glucose monitor (CGM). One version will be FDA approved and use the Tandem X2 pump with the Control-IQ control system. The other option is an open-source Loop controller running on an iPhone that communicates to an OmniPod.

As a reminder, a hybrid closed-loop system is where an insulin pump communicates with a CGM and feeds information into a control algorithm that works to control glucose levels. The system largely does this by increasing and decreasing the basal insulin as glucose levels rise and fall. The user still needs to input carbohydrates and make adjustments for exercise, as well as make occasional corrections for high glucose levels.

The first FDA approved system was the Medtronic 670G system that uses their Guardian sensor. The best results with this system come from entering carbohydrates in advance of meals and calibrating the sensor four times a day. For people who can get accurate sensor readings and are able to manage the system, it helps to increase the time in range between 70-180 mg/dl and does a good job of adjusting the overnight glucose level to 120 mg/dl. We have some patients who have started on the system and found that the sensor was not accurate, required too many calibrations or that is was too hard to make it fit into their life with diabetes. However, other patients love the system and are achieving 70% or more time in range.

The next FDA-approved system is expected in late summer or early fall, this will be the Tandem X-2 pump with an upgrade to their Control-IQ software. Once it is approved, the software update will be available shortly afterwards. Current X-2 insulin pumps can upgrade their current pump with a software update to run the new software. that pairs with a Dexcom G6 CGM. This will be an upgrade from the current Basal-IQ system that now controls the basal dose to help prevent glucose levels less than 70 mg/dl. The Dexcom G6 is considered the most accurate CGM on the market and it is factory calibrated, but there is an option for the user to enter a calibration is needed.

The big news in the open-source, closed-loop community is that the Loop team has worked to make a connection to an OmniPod. They have recently released the code to turn an iPhone into a Pod controller paired with what is known as a Riley-link device that serves as a communication bridge. This provides the option of using a current insulin delivery system instead of the previous delivery system of using an out of warranty MiniMed pump.

The Loop system will work with the OmniPod Eros pods - the ones that communicate to the original OmniPod PDM. We have a patient who was an early beta-tester of the OmniPod Loop and many others who have shown interest. Much of the interest has come from tech savvy patients who are using the Loop or OpenAPS systems with the older Medtronic pumps. These people tend to be comfortable with technology and trying out a novel system of diabetes management.

These systems are not FDA approved and we can not officially prescribe them. However, safety is key, and our team has had a lot of experience in helping patients use these devices. The FDA warns that the risks associated with these systems is not yet known.

OmniPod is expected to launch their own FDA approved closed-loop system next year and there are other groups and companies working to release their system in the coming years. Expect continuing developments in this fast-moving field, we will do our best to keep up to date with the research and are available to help our patient decide what is right for them.

Links to the current systems and news:

Medtronic 670G
Tandem Diabetes
The Loop System
The Loop OmniPod:
Loop Facebook Group
History of the OpenAPS
OpenAPS system
The Tidepool Initiative to get an open-source system approved by the FDA