Couple weeks ago, I could not enter Auto Mode on my 670G for three days due to the dreaded “BG Required Loop.” As a solution, I eventually had to change the sensor to be able to re-enter AutoMode.
God knows I have tried to resolve the issue using every advise given online in forums (including trying to “fake” the system by entering a number just above or below your last entry) but these have only worked only a couple times.
What I think Causes the BG Required Loop
At issue I think is the way that the 670G calibrates the Guardian sensor. It seems to be programmed to validate the BG you’ve entered into the system probably based on the ISIG history and its predictive model of where your BG readings are trending towards.
So if you enter a BG reading from your glucometer that the 670G does not think makes sense to its predictive model, it initiates the “BG required loop”. But when you test again, the BG number you get from your meter might be more or less the same as the one you got before.
So as soon as you enter a new number, it is once again rejected and the loop persists and so on.
I personally think the “BG required loop” has nothing to do with the pump but has everything to do with the so-so precision of the Medtronic Contour next Link 2.4 meter (the meter that comes with the pump).
Just perform 5 repeated measurements using this meter on the same site and you will be amazed by how varied the readings can be, they are literally all over the place.
My Solution to the BG Required Loop
I decided to try the OneTouch Verio meter for my calibrations instead of the Medtronic Contour next Link 2.4 meter.
From the onset I was amazed at how easily it is to enter Auto Mode with the Verio. I have actually decided to ditch the Medtronic Contour next Link 2.4 meter and use the Verio permanently despite the small inconvenience of having to enter my meter readings manually into the pump.
The pump readily accepts values from the Verio even when I have a single upward or downward arrow with no problem.
And the values are impressively close between the pump and meter as you can see below.
As a matter of fact, when I have used this meter continuously, I have not encountered the BG loop. I ran out of strips last week and I had to use the Contour next and it was a disaster, with one sensor failing completely.
The precision of the OneTouch Verio/Ultra is great but I believe it is not as accurate as the Medtronic Contour next Link 2.4 meter (see my comparison article).
But my last HbA1c were within my target range so I do not think the OneTouch meters (ultra and Verio) are really off especially over a 3 month averaging period.
UPDATE 12/4/18: One of our readers also noted that they have had success using the ReliOn Premier Blood Glucose Monitoring System to calibrate their Medtronic MiniMed 670G .