Introduction

Welcome to LoopTips! The purpose of these pages is to help you make the most of your DIY closed-looping experience. In particular, these pages support users of the Loop app. These documents have been a long time in the making and as always, your feedback is welcome. If you have comments, please feel free to provide input at the Looped Facebook Group, Loop and Learn Facebook Group or in Loop's Zulipchat.

LoopTips is a companion to LoopDocs. LoopTips does not cover the build or installation of Loop app. If you have problems with building your Loop app or troubleshooting the technical aspects of Loop operations, please head over to LoopDocs for help. The LoopTips pages are specifically related to understanding how your loop is recommending the actions being taken, and how you can improve your blood glucose outcomes on Loop. Some of the pages that originated in LoopTips are now included in LoopDocs. Don't be surprised when you find links between the sites. (The color bar is deliberately a different shade to help you know where you are.)

What is a closed loop?

The U.S. Food and Drug Administration (FDA) has a general definition of an "artificial pancreas device system" (aka closed loop system) on their website, quoted below.

"Most Artificial Pancreas Device Systems consists of three types of devices already familiar to many people with diabetes: a continuous glucose monitoring system (CGM) and an insulin infusion pump. A blood glucose device (such as a glucose meter) is used to calibrate the CGM.

A computer-controlled algorithm connects the CGM and insulin infusion pump to allow continuous communication between the two devices. Sometimes an artificial pancreas device system is referred to as a "closed-loop" system, an "automated insulin delivery" system, or an "autonomous system for glycemic control."

An Artificial Pancreas Device System will not only monitor glucose levels in the body but also automatically adjust the delivery of insulin to reduce high blood glucose levels (hyperglycemia) and minimize the incidence of low blood glucose (hypoglycemia) with little or no input from the patient."

What is Loop?

The Loop app is a do-it-yourself closed loop algorithm and user interface, developed through the work of community volunteers. You can read about the history of Loop development in LoopDocs. Loop predicts future blood glucose based on basals, carbohydrate intake, insulin deliveries, and current CGM readings. These blood glucose predictions provide Loop with the information needed to recommend a temporary basal rate to attain a targeted glucose range in the future. The system can either operate as an “open loop” by making recommendations to the user for their approval before enacting or as a “closed loop” by automatically setting the recommended temporary basal rate.

As exciting as this sounds...we should first get the caveats out of the way. There are some limitations on what kind of pumps/equipment are required. This system doesn't work with most pumps and requires you to do some work. The pumps that are supported and the directions for building are thoroughly covered in LoopDocs.

Disclaimer

While it may seem obvious, please consult with your health care professional regarding your diabetes management. The suggestions and discussion in LoopTips are not a one-size-fits-all nor intended to replace the input from your doctor. You take full responsibility for building and running this system and do so at your own risk.