Observing the closed loop

After you have created a schedule with cron, your loop will automatically run.

Starting with low glucose suspend mode

You may notice that the loop is only going to temp you til your netIOB (this means the net amount of insulin compared to your normal basal rates; so if you temp to 0 and your basal is usually 1.3; you will end up with negative netIOB) returns to 0. This is an important safety feature to help you observe the loop for three days in this mode.

At this stage, if you consistently see net negative insulin amounts at the same time every day (use Nightscout reports or similar to observe), then you may be over-bolusing for meals and/or your basal rates are too high the 1.5-2 hours before the low BGs are occurring.

If you observe this, you’ll need to tweak your basals or consider how you bolus for meals - your I:C ratio may be off.

Make sure you check this out before moving to the next stage of tuning the loop.