Sensor longevity and repeated BG alerts from 670G

My trainer told me that 3G sensor would last for 7 days but I’ve used the 670G and sensors for almost a year now and have never got more than 5 days. At most, in the fifth day of use, I start getting prompts to enter a BG. Upon entering that, I immediately get another prompt to enter a BG along with a msg to calibrate the sensor.
Today, I’ve been getting these every 20 minutes even though the SG and BG are within 10. This getting very irritating. No help from the Medtronic support line, either. I get a different answer every time I’ve called. On the last call, I was told I’d placed the sensor incorrectly…after 5 days???
Has anyone else had this frustration?


Sorry to hear you are having this problem. I think this has happened to me only once in the last year or so that I’ve been on my 670/G3. I’ve managed to extend the sensors a few times, but have not been particularly successful with that.

Tell us more about your placement and/or anything else you can think of. I’ve worn them on my stomach and love handle area as I carry very little fat. I recently tried my calves and aside from the sensor/pump communication being lost a few times when i’m sleeping, it worked surprisingly well there too.

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As far as how long the sensor lasts, I have been told that the more your numbers go up or down (really high or really low) the shorter your sensor life will be, which may be why you only get about 5 days. I recently tried to call Medtronic to ask why it asks for Enter BG multiple times, and the person I talked to just said a bunch of useless stuff. Even if I can’t change it, I want to know the algorithm used by the pump to determine when to get rid of the message. There must (supposedly) be some reason they don’t always want to use the first one, but what is that reason? Is that reason so confidential that I can’t know it? I have definitely had the frustration of repeatedly being asked to Enter BG, it is probably one of the very few things about the 670G that I DON’T like!

I place my sensors in stomach/love handle areas also. At training, the trainer placed the sensor on the back of my arm (tricep area) and said to try there. I asked her if she’d ever put one on herself there one-handed. The only response was “I don’t use a pump, so NO”.
I used the previous generation of pump/CGM with no issues. Even though they were advertised as 6 day usage, I could get 10 - 14 days with no problem.
Another issue I have is with the adhesive. When I work outside and sweat, the adhesive will not hold. I ordered some SkinTac swabs that I apply before I putting the tape on and that works much better if you don’t mind ripping it off when you change the sensor.
Don’t get me wrong, the system works great when it works. My A1C has gone from +9 to 7.1 on my last test, but it’s very frustrating at times.

After spending hours on the phone with Medtronic support folks (1 hour Friday and another hour Saturday night with support and then ANOTHER hour with the supervisor of the second person), the solution to getting my pump back on AUTO mode and putting an end to the annoying “ENTER BG” messages every 20 minutes was to turn AUTO MODE off overnight.

Sunday morning, I turned AUTO MODE back on and entered a BG when prompted and no more issues. (This was the recommendation of the supervisor.) He even called me back Sunday afternoon to check if everything was working correctly.
Evidently, the program in the pump gets stuck in loop and that’s the work-around. It would be nice if the folks answering the phone knew that! It is a known issue.

I can’t say my sanity is back intact, but it is back to base-line.

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I used to use the Oval Tape that comes with the Guardian 3, and when I would try to “rip it off” I would often end up actually ripping the tape instead and needing to peel it off slowly instead. What I started doing was using some of the patches from GrifGrips as a “barrier” between the tape and my skin. I also started using Unisolve to make removal less painful.

I never tried turning Auto Mode off for more than a minute or so when trying to get back into Auto Mode, so maybe I’ll try turning it off for a longer period of time the next time I have trouble getting back into Auto Mode. Thanks for that suggestion.