I have questions about calibrating my MM CGM system

I sometimes get the crappy scenario where my sensor glucose (SG) reading is way off (this morning, for instance, the sensor read 177 but my glucose was actually 107). I know this happens, there is a lag, glucose was rapidly decreasing due to a bolus, etc etc…

so when I provide a “Meter BG” to the sensor, how does it actually use that info? It doesn’t appear to instantly calibrate to that value, so how does it incorporate it? Any advice or info is really appreciated to help me clear this up! thanks.

You know, if you think about it, you will understand that MM is scamming all of you with their CGMS. Their system is still in the “beta” stage. Compare the users’ experience with the Dexcom 7+ system - no hassles about anything at all: easy insertion/removal, easy calibrations, and accurate readings. And MM CGMS? Painful insertions, extremely confusing guidelines about calibrations like “do not calibrate if bg is changing rapidly” or some such nonsense, and wildly inaccurate results. That is how they yank you about - “oh, you did not calibrate it the right way” i.e. the problem is not the CGMS but it is the user. How do you even tolerate such BS from this company?

Everytime I read about poor users having difficulty with the MM CGMS, I feel like screaming out “can’t you see you are being scammed? isn’t it obvious??!!”. Return this useless piece of costly trash to MM and switch to something else like the Abbott system of the Dexcom system. You will then see what a CGMS really works like, and reap the benefits of having something work to keep you healthy.

When I was on the MM CGMS, my control got worse because I trusted the CGMS - flat at around 100 mg/dL for an hour or so and I check with a finger prick and it is really 210 mg/dL or so.

I should stop now because I feel my blood pressure rising sky high and this impotent rage that is building up.

Wake up, people, boycot MM CGMS. They are scamming you.

There are a very small minority here who find the MM CGMS useful. I don’t know how you do it. I find it very hard to believe that it is smooth sailing for you, either.

John, thanks , but no thanks for me and millions of others reading your response . Your observation , not mine !..I should post this under the the discussion " what is the most annoying comment you 've ever gotten about diabetes " , but I won’t .Today is my day of getting hooked , I suppose .
My BG’s not doing great …am recuperating from a cold and laryngitis ( after I posted somewhere , that since I take Vit D , colds have not been a big part of me lately …well I fibbed :slight_smile: …finger poke result just now : 9.4 ( x 18 ) ,Medtronic 's CGMS result 10 ( x 18 ) and now 5 min. later at 9.7 ( x 18 ) . I call this a decent comparison and find no reason to discontinue the system .Calibrating suggestions as the other John suggest are much more useful and I bet his BP is not rising sky high .
I do not live in the US and even for those living in the US , the alternative may just not be available . Had you thought of that , prior to posting , than I would not have to respond here …remember I said : I got hooked .
Be well .

I’ve been using MM CGMS since May of 2009 and am NOT happy with it. Calibrating is taking over my life, and only 25% of the time do I get accurate readings.

Right now I am trialing Dexcom and if I had 5 thumbs, I’d give it a 5 thumbs up. The accuracy from the very beginning is similar to the few days that I would have good readings on MM CGMS. And calibrating is as easy as testing my BG and punching it in. I still am in shock that I do not need to not eat, bolus, exercise, and have a steady BG before calibrating. That is nearly impossible for a human being who is diabetic.

I also am SO SICK of reps, doctors, nurses, CDEs all pushing MM CGMS. They all say how MM is the leading company, the most research, most money, blah blah blah. I don’t know why they do this. I also do not understand how it works so well for those few people. How are they not so incredibly frustrated with calibrating? Even if they are getting good calibrations, there is just way too much to try to control to get a good calibration…I just don’t get it.

Anyway, preaching to the choir a bit. And I don’t think so much that MM is scamming us, but I do think that they need to let me think for myself, and decide for myself which system is better. And I’m 99% sure that after this trial I am starting the paperwork for a Dex.

Elizabeth , I calibrate , when numbers are relatively stable …no more than twice daily with added times at original set up ; try to do this before a meal …I use my Bayer Contour Link meter to calibrate and I have another meter I use for finger pokes and this meter does does NOT send result to the pump …for me calibrating is the least of my problems having diabetes. I place the sensor in me at night ; the following morning I attach transmitter . And ofcourse you need to think for yourself …diabetes is a disease that does much better , if one does just that .

Dude - I am not being scammed. And I’m not lying. I just happen to be a PhD in electrical engineering who can easily handle the most difficult of gadgets. Guess I’m lucky that way. There are a few reasons I use the MM CGM:

  1. My sensor readings are accurate 85% of the time. The rest of the time my blood sugar is either rising or falling too fast for it to keep up. They’re so good that I’ve never had an A1C above 6.0% on the MM CGM.
  2. My insurance would only pay for the MM CGMS - not Dex or Navigator. So I’m shelling out about 10% of what I would have if I had gone with the Navigator or Dex.
  3. My transmitter is over a year and a half old and still truckin so I’m not about to ask my insurance to pony up for a new one (if they were to cover Dex or Navigator) b/c what I’ve got is working just fine.

I think there are more people that have good luck with the MM than you realize, because as a rule, folks don’t post about something that doesn’t give them problems. I know there are quite a few people who cannot get the Dex to work for them, so do you think they’re being scammed too? I’m not really sure why you felt the need to insult all of us who have no issues with the MM, or who cannot afford the other CGMs. Not cool.

I am envious , John as a seventy year young person , with no diabetes complications …viewing these stats. NO B.S here.
I hope you get Emily motivated too .
Where did I read , that S.Woodward suggested using a pillow to lie on, to avoid the " flat line " , while lying on the sensor at night ??

Good to hear positive reports about the MM CGMS. I have been using it on and off since October 2009. I found the calibrations and insertions intially vety diffcult and time consuming.I found that searching for,And searching for a calibration time that would work to get accurate readings was frustratiing…The learning and acceptance curve has been long, but I will stay with it, as t I am learning more and more about it, I really love it when I actually can prevent a high. I am hoping I become more and more proficient at mastering the MM CGMS.

God Bless,

i would like to thank people for posting, but boo-hoo to the negative posts! Why would you bother if the title of my post said MM CGM? I find that weird. Ah well, some get their kicks in funny ways. But to the point, I cannot get another sensor in my particular case right now, so i guess I am making due with what I have!

I think I will try to scale back the calibrations, I might be confusing my sensor! All the advice and small tips are great, thanks again for helping me with this topic!


You know, you are free to buy their system or not.

Personally, it has worked exceptionally well for me - and I have worn it every day for the past year.

Yes - there are times the sensor does not match your BG - why does this happen?

1.) First off, the method they use to determine BG is different than a finger stick - and this method - reading the sort of fluid they do - causes the sensor to be about 15 minutes behind reality. If you can’t accept that - then the sensor is not for you.

2.) I suspect that due in part to the lag - it is exceedingly important that you calibrate the sensor to a BG reading when your BG is in steady state. Not when it is moving. If you are unsure if you are in steady state - test your BG - wait 15 minutes and test again. If the numbers are close - then you are in steady state and are good to calibrate.

3.) Sensor insertion is also critical - I have noticed a few times when pulling the needle out the sensor will sometimes pull out a little - if the sensor is not all of the way in it will not provide good readings.

Finally - if it were beta or a scam - then it probably would not have recieved approval to be used in the United States.

I don’t use the MM CGMS, but the ideas are the same! When I calibrate it never pops up to the exact number. Generally, it takes 15 minutes or so before it aligns with my reading. You just have to give it time.

I have found that less is more when it comes to calibration. I only do it twice a day, and leave it be during the day(unless it is unusually way off…even then I may let it sit to see if it self corrects, often times it does).

Other than the negative post, the information on the MM is good stuff.

The guess by some engineers is that when you put pressure on the sensor, Nav, MM or Dex, the movement of interstitial fluid is reduced and as the tissue absorbs the glucose in the area, the amount of glucose in the fluid which is being seen by the sensor, is reduced. I look at it as kind of like “glucose sleep” like when you foot gets numb because you are sitting on it…well something like that.

I have my ups and downs with the MM, but I love it. I’m still learning how to get it working better everyday. I now put the sensor in the night before plugging in the transmitter and that is working great for getting it started. I have had the chance to wear the MM and the Nav side by side and I can hardly wait for the new MM Revel is out to see how much better the software works for predicting lows and highs. There are new sensors coming out this year from and three companies and that will be a big step to better CGM performance and reliability.

The “be patient” when calibrating should be a mantra for CGMs, but the MM really need a few hours of steady BGs to be calibrated. As said, there is no reason to enter a BG when it ask if your BG is going down up.

All three systems have their good and bad “features” and if your insurance will only by the MM, the Nav or the Dex, take it now!

I could not agree more. After a little over a year on the sensor - I could not imagine going back to not wearing the sensor.

The predictive alarms on the new Medtronic Revel are turning out to be exceptionally good.

You still need to calibrate correctly - and that comes down to patience as Mr Woodward suggests.

The 15 minute delay for the old threshold alerts were alway too late for me catching my lows. Setting the predictive alarm to 20 minutes - the pump now has warned me of an impending high and impending low - and for the first time this was news to me (not already high or low, and the pump going - oh,yeah - I noticed too.)