Medtronic 670G Auto-mode "Learning" Period

This is for people who are considering upgrading to the new Medtronic 670G system and using Auto-mode. Users are required to wear the insulin pump and CGM sensor for a week so the pump’s control algorithm can “learn” about your basal insulin needs. The pump will allow you to turn-on auto-mode after about 4-days of CGM sensor data has been logged.

However, the pump can take up to a month (Medtronic’s words) to fully “learn” your insulin needs. The first time I turned on automode, I saw my BG steadily climp into the mid 300’s. I turned it off after about 6 hours, as I was not getting enough background “basal” insulin. A few days later, I tried again. Not as bad this time, but still pretty lousy. Turned auto-mode off again after about 2 days (same issue).

After about 3 weeks, things are starting to get smoothed out. But there are other MAJOR GOTCHAS with the 670G system (see my other Medtronic 670G posts).

For a lot of people, expect about 3 weeks of intermittent hyperglycemia (high blood sugars) and general poor blood-sugar control while the magic black-box is “learning” how your body works.

THAT SUCKS. I have about 1.5 years worth of 630G insulin/BG/carb data logged into Carelink. I don’t think it is too unreasonable to expect Medtronic should have taken advantage of this historical data and developed a way to train the 670G algorithm based on your personal data. That would probably get you 90% of the way there, and would cut the painful “learning” time down to a few, more tolerable days (instead of weeks).

But, Medtronic choose not to make things easy for us 670G users, by forcing everyone to start with the default auto-mode internal settings.

“Thank you for Choosing Medtronic” - You can bet, this (670G Pump) is the last time I will be choosing Medtronic.

I, too, am having some difficulty adjusting, but my issues are mostly lows. Yesterday I had to eat about 12 glucose tabs throughout the course of the day. Since I’m overweight, I hate to have to consumer all of these extra calories when I’m not even eating. I am also unhappy with how long one has to wait to speak to a Minimed rep when calling for assistance. They need to staff up!

Consider that Medtronic may not have had a choice in this, the FDA is heavily regulating the introduction of “bionic” or “artificial pancreas” pumps in America. The learning period you speak of may have been a requirement of the FDA and not a decision of Medtronic.

I just had to replace my 670G when it fell and broke. Ugh! And, I am happy to report that Medtronic was really awesome with getting me the replacement. So, while I too can grumble over there often very slow customer support, this time it was different. Phew.
In terms of the Learning Period, I just had to go through that all again, and yes, it is frustrating that it can’t be “learned” through previously collected data from Carelink. I had to stay really diligent with extra finger sticks and corrections but it’s finally getting back (mostly) on track after about two weeks, and I’m hoping that will only get better.
I think new users should be better educated on the amount of time it really takes to get it up and running. And beyond that, it takes many months to really see improved control, at least it did for me.
It’s definitely not the “miracle” I was hoping for but I do think it’s moving in the right direction.

I had the same “learning curve” and, in fact, I removed the 670G and CGM twice and returned to insulin injections due to inaccurate sensors, and have also had issues with long wait times for customer service. I spoke to a wise Medtronic rep at some point during the 1.5 months of horrid BG levels, and he told me that people who have the need to have tight control over BG levels are the ones who have difficulty with auto mode. REALLY? I am one of those people! But when I consulted with my doctor and my Medtronic rep, we made adjustments to my basal dosages, insulin sensitivity and bolus dosages, I have had great BG control and love the freedom that this pump provides! I am no longer hypersensitive to lows, but if my level gets above 170 I can feel the effects immediately - I feel HORRIBLE; groggy, confused, sloooow!

i still experience occasional “looping” and the pump asking me to submit a BG reading every five minutes but found that my compulsive entering of the last BG level on the screen is causing a lot of this issue. If I wait it out, it will pass.


I had a lot of trouble with inaccurate sensors, until I started using the Bayer Contour meter to calibrate the sensor. I was using another BG meter for a long time, because I could get the test-strips super cheap ($2/box of 100). I found I can mail-order the Contour test strips from Medtronic for about half the cost of buying them through my local pharmacy, if that helps.