I just started Medtronic Enlite CGM with my Paradigm 523. It’s working out well so far. I am curious though…since I’m not using the new 530 my pump only recognizes the Enlite for three days and then I have to restart. I tried the ‘reconnect old sensor’ menu option, but it never works! I always have to use the ‘new sensor’ menu option which is kind of a pain because then I have to wait 2 hrs. to check my bs. I keep meaning to call Medtronic and ask about this. I assume it is just part of the hassle pairing the newer CGM with the older pump model (I had to have a special Rx to use them like this since I guess the Enlite was never tested with the older pumps). Anyone else using it this way? What’s the longest you’ve kept your transmitter on? I changed out at day 6 like they said to do, but I’m wondering if you can wear it longer.
You will have to use CONNECT NEW SENSOR, same as with the newest MM pumps. Two hours goes by pretty quickly, once you get into the groove of doing that, but it IS a pain to have to do it every 3 days as opposed to every 6 days. How about upgrading (don’t go thru insurance!) for a fee, to the newer pump? It will be well worth it, IMO. I’ve worn one sensor for 25 days, and the xmitter needs to be charged every 6 days. The battery won’t go beyond 7.5 days in my experience. I typically can restart a sensor at least once or twice before it stops working well, but that only holds true when I wear them on my arm. See my other threads on the subject.
This option does work. It is simply not intended to be used to connect to a sensor which the pump’s firmware has decided has “expired”.
Here is my understanding of how the three different Link to Sensor options on the Medtronic pumps work.
- Find Lost Sensor
I believe this option is intended to be used when your pump and sensor have been disconnected for more than the 40 minutes which the MiniLink transmitter can buffer. If I recall correctly, when you use this option the pump will (usually) prompt you with a meter BG NOW calibration alert. This calibration is treated as a regular calibration meaning that the pump will set the countdown for the next required calibration to 12 hours later. The pump’sSensor Agevalue is not changed.
- Reconnect Old Sensor
While this is largely similar to Find Lost Sensor, the calibration is processed as a first calibration. All previous calibrations are ignored and another calibration will need to performed within 6 hours, not 12, of this one. The pump’sSensor Agevalue is not changed.
Note: I use this to calibrate whenever my ISIG values have suddenly changed and the calibration factor for the current calibration would be significantly different from the previous factors. In other words, this can be used as a kludge to attempt to avoid the dreaded “Calibration Error” alert.
Another reason to use it is as a way to “force” the pump to accept the meter calibration BG you enter as THE only value to use. The pump will not attempt to “average” in the previous calibration BGs you entered. It will only use the meter BG NOW value you enter for this option.
- New Sensor
I believe this performs essentially the same function as Reconnect Old Sensor. The difference is that using New Sensor resets the pump’sSensor Agevalue to 0. For an 723/523 or 722/522 pump this is three days and for the 530G it is 6 days.
It’s not quite that straight forward. The 2 hour sensor calibration sequence is not triggered by any of the pump’s Link to Sensor options. Instead that process appears to be triggered whenever the MiniLink transmitter is “reset”. This (typically) happens because the transmitter was disconnected from the sensor to recharge it.
While I am not completely sure what happens during that 2 hour “Warm Up” process, I don’t think it has anything (much) to do with the pump. Instead the MiniLink transmitter appears to be calibrating the ISIG output from the sensor. I think what is happening is perhaps very loosely analogous to how an electronic scale will “zero” itself when it is first turned on.
The bottom line is that when at the end of the first three days you perform the “New Sensor” operation, the pump should prompt you with meter BG NOW almost immediately after it reconnects to the transmitter. You won’t be without Sensor Glucose (SG) readings for 2 hours. The only gap will be about 15 minutes while the pump collects three ISIG readings from the transmitter to use for this “first” calibration of the “new” (to the pump at least) sensor.
You will also have to provide a second calibration BG within the next 6 hours, (Unless of course you decide to do Reconnect Old Sensor because you’ve decide that first calibration is no longer relevant and you want to restart calibrating “from scratch”.)
As phoenixbound mentioned, the battery in the MiniLink transmitter typically lasts no more than about 7 days. You can if you wish do another “New Sensor” operation on the sixth day to continue to use the sensor until the transmitter battery dies. If you wish to attempt to use the sensor for a longer period than that then you need to very, very carefully disconnect the transmitter from the sensor, recharge it, and then reconnect it to the sensor.
If you do remove, recharge, & then reconnect the transmitter, you will also need to wait through another 2 hour Warm Up calibration period. This is because the transmitter resets itself when it is disconnected from the sensor. It will no longer know where “0” is and will need to perform the 2 hour Warm Up process to figure it out again.
meh.
@MKSSS I use the same x23 pump as you, also with Enlites. Although I have not had any first hand experience with the 530G, I have been underwhelmed by what I’ve read about it. The 530G strikes me as essentially the same as an x23 only with a few more menu tweaks. The most (only?) significant change seems to be the addition of Threshold Suspend. Unless you have few or no limitations on when and to what you “upgrade” to, my advice would be to ignore the 530G and instead wait for the newer MiniMed 630G to become available in the US.
Unlike the 530G, the 630G has a number of changes which I feel make it more worth one’s while to switch. The big add is a function the Medtronic marketeers have dubbed “Smartguard”. The pump’s firmware attempts to predict based on your CGM when you are 30 minutes from a hypo and can be set to turn off your basal. If/when your SGs “recover” the 630G will then automatically resume your basal
The 630G also uses a newer … hopefully at least slightly improved … CGM transmitter which Medtronic refers to as the “Guardian Link 2”. 
I think it is also likely that the calibration algorithms in the pump’s firmware might have been improved. (One, can self-delude … eh, dream, no? 
)
Thank you. That is so helpful! The calibration between my 3 day period wasn’t as long…you were right. I’m still trying to learn about the ISIG #'s. I found this:
http://forums.childrenwithdiabetes.com/showthread.php?20347-CGMS-ISIG-and-Calibration-Guidelines
I’m planning on sitting down soon and spending some serious study time on the topic. Math is not my strong suit, ug. Even with me not paying any attention to the ISIG values and calibrating based on the training I had starting my CGM my #'s haven’t been far off my bg meter. The other night my pump alarmed me at low. I checked at 3am and was 88. After that my pump alarmed 3 more times and I just kept ignoring, but eventually I felt bad, checked, and I was at 50!
You both have posted a lot of info. about sensors which I’ve been reading. And I thought starting on a pump was complicated…child’s play compared to this whole new CGM. I was offered the opportunity to upgrade out of my own pocket, but I choose not too since I’m a cheapskate, and I didn’t want to be locked into another 4 years with a pump that wasn’t that much different from my 523. I don’t really need the threshold suspend at this point in my life. Also, I’m waiting for the newest Medtronic in 2017 when my warranty is up. If it doesn’t blow me away I’m switching. If Medtronic can’t figure out how to make their pumps smaller and watertight then goodbye Medtronic. Plus, I don’t know why their CGM can’t be as good as Dexcom (or as good as people say it is). Although now that T:Slim has been on the market for a while longer it is interesting to see people starting to complain about certain features- good to learn about all the pumps out there.
Ok, so do you think the difference between Dexcom and Medtronic is how they are made or or what??? I knew going into my Enlite that Dexcom was more accurate, but I wanted to just stay with everything Medtronic and although I know Dexcom is soon going to the “cloud” I really did NOT want to carry around a receiver. I love the idea of it all being contained in my pump.
I’ve seen discussion about Dexcom having the same issues I have with the enlite. My enlites are very accurate once I calibrate correctly. Always the first day is iffy, but I see ppl with Dexcom saying the same thing.
Yes, I did wonder about that. If interstitial fluid is different from blood glucose then it would follow the #'s would never be completely perfect no matter what CGM you use.
It depends on how quickly your BG is changing. If your BG is relatively “stable” then your interstitial glucose should also remain relatively constant and your SG (Sensor Glucose) can be calibrated to “match” your BG meter reading. In any case, while I want the BG & SG to be close, it is also important to always pay attention to the trend. If the SG is rising or dropping it should imply that your BG is doing the same … if the sensor is working well.
Of course, the whole comparison game is more complicated than I think most people assume because the BG meter reading itself is not accurate. If you take two different samples with your meter, one after the other, will they be identical? I doubt it.
It’s hard to say because both companies are incredibly secretive about their glucose sensor technology. It may well be that the chemistry of Dexcom sensors is better than Medtronic’s. But even if it is, I’m not sure that explains most of the difference in perception between the two technologies.
I think the main problem with the Enlite is the physical design. In my opinion the Enlite sensor with attached transmitter is too much like a lever. If the physical setup of the sensor and transmitter is wrong, then pushing on the transmitter can actually lift the sensor up and away from your body, a “rocking chair” effect.
I think paying attention to how the sensor is inserted, taped, attached to the transmitter, and then taped again can make a big difference between getting good results from the Enlite versus some of the horror stories one can easy find out there. I think of the Medtronic CGM as a “Goldilocks” technology. It works fine, even really good so long as everything is just right! If you make mistakes during the setup, which of course humans do, then it can really throw off the results.
Of course, maybe it’s not that at all. Maybe some people are just “lucky” and others aren’t? In any case, even though I think the physical design sucks, Medtronic is clearly sticking with it for at least the near future. Although the internals of sensor & transmitter used with the 630G have been tweaked, the basic external physical design of the sensor and transmitter is unchanged. 
I don’t have trouble keeping the sensor in place. Removing the tapes to recharge is what’s tricky. 
Me either. Mine works perfectly fine and I’m not the greatest inserter in the world either. Mine works good enough to bolus by it and hasn’t been a “horror story” at all. I don’t even tape mine the way they say because I’m highly allergic to the glue and I’m sure I would be allergic to dexcom too, because I’m allergic to everything that sticks to my skin.
When it comes to Enlite, the “mileage” you get certainly does seem to vary. A lot. I don’t have any good explanations for this, only speculations … and sometimes not even those.
Here’s a link to my sorta favorite Enlite trial horror story:
“My Experience With Medtronic’s Enlite CGM System”
It starts out with the typical “these readings are complete crap!” tale and then segues into Bizarro World territory. She visits her endo’s office to replace the “bad sensor” and for five times in a row when she removes the inserter she pulls the sensor out along with it. For three of the five tries the doctor’s nurse is present.
OK, I probably would have taken her word on it that this actually happened, but she also includes the pic below apparently as “proof” that the bad stuff really did happen. It’s one of those tales where I really want to have been there to see it for myself … and of course proffer the inevitable Y chromosome based “helpful” suggestions. (aka “Here! Just let me try it!” syndrome )
I have a different take on the events since something vaguely similar actually happened to me. Sometime during the first 20 or so sensors I did the press/release to insert and then completely forgot to press the inserter button again when I removed the inserter.
What happened? In my case the sensor stayed attached to me but removing the inserter also removed the insertion needle.
It then suddenly became “obvious” to me why Medtronic has such an awkward button pressing process for the Enlite insertion. The original intent (I am guessing) was for people to always do it the way I had mistakenly done it. The original design probably intended that the insertion needle would be removed at the same time that you removed the insertion device.
But I can also guess that what happened “in the field” was that time and time again people were pulling out their sensors when they lifted off the inserter. Medtronic then decided to “fix” this by having people press the button before removing the serter and then removing the insertion needle as a separate step.
But I digress …
I guess I did have two of the inserter’s replace. Not sure if they were defective or I damaged them in some way. MM replaces them and replaced all sensors, so I didn’t think it was an issue. But I know what u mean by the insertion process. I found it wierd at first, but doable once I got used to it. My biggest problem was with the adhesive though and I have that problem with infusion sets and ekg leads and anything else that sticks to skin.
What “bad thing” had happened that prompted Medtronic to replace your inserters?
I’m still using the inserter which my nurse educator found for me after rummaging around in her “junk drawer” for a minute or so. 
(That’s actually also where my first few Enlites came from. They were “expired” ones I think she was going to use to “demo” the insertion process.)
I have definitely had some “questionable moments” since that one time when I simultaneously removed the insertion needle along with the inserter. Inserting unassisted in my arm seems particularly prone to inserter removal problems. But I have never (knock on wood) pulled off the sensor while removing the inserter. That may be true for two different OCD prompted things I do.
First, I always leave the serter gently in place (no hard pressing) to let the pressure sensitive adhesive bond. I wait at least the 10 seconds Medtronic suggests, but often more like between 30 to 60 seconds. (Hey, if a little is good then more is …)
Second, I also “feel my way” when I’m raising the inserter. If I feel “too much” tugging on the sensor I stop and try changing the orientation of the inserter to see if I can free it from whatever way it seems to be “snagged”.
I frankly don’t have a lot of faith that the adhesive is going to hold sensor in place when I’m removing the inserter. So I am always very cautious during this step. Perhaps other folks are not? How could one really know? 
There is a flat piece of the works, about the middle of the short side of the inserter. If this is bent and it’s hard to notice it and easy to bend it, the inserter does not insert properly. I had tried about 3 times before I called medtronic. The replace the serter and sensors both times.
I’ve had a couple sensors sort of snag and I’ve slid a knife blade (all D-maintenance is done in my kitchen, LOL…) in between the snagged inserter and the sensor to keep the sensor pressed down so it doesn’t come up while I’m wrasslin’…
Still not seeing it. In the pic below is it the smaller, bottom circled area or the larger or neither of these?
The smaller square piece at the bottom. That sometimes bend downward and you don’t even really notice it. If it bends, it doesn’t work.
Huh. While I have thought to slide something between the inserter & sensor when I’m nervous that removing the former might also tear the latter out, it never occurred to try using a table knife. I think I’ll add one to my arsenal of insertion tools. 
Thanks for the idea!