Inserting Medtronic Enlite CGM in upper arm — How did that work for you?

Continuing the discussion from Medtronic 640g - Offical Details and photos:

I have tried inserting an Enlite on the back(ish) part of my upper arm three times so far. My experience with this is that it is sort of really good while also, at times, really annoying.

Good because I feel I get noticeably better performance from the sensor. ISIGs in my experience have so far been generally stronger and remained that way for a longer period over the life of the sensor. Also, the accuracy seems generally better as well. I also believe that … with the exception noted later … I tend to jostle the sensor less in that location as I go about my day to day activities. Another definite personal plus is that when my cats sleep on or walk over my stomach while I’m laying down, they won’t disturb the sensor. :smirk_cat:

FWIW, should anyone be curious, it’s a location where you can easily show someone what the sensor looks like without pushing up against common social TMI boundaries. :smiley:

The really annoying aspect for me was essentially that there is an adjustment period to acclimate to the new sensor location. I definitely have to make sure the pump is always on the same side of my body as the sensor to avoid “Weak Signal” disconnects and alarms. I also found I have to consciously remember to not rip the sensor out when I’m washing my upper arm in the shower. (I tend to be on autopilot while I’m soaping and rinsing. :blush:)

Of course, the most obvious potential problem is the insertion and overtaping, especially if you are doing this by yourself. The trick of pushing the back of your upper arm “towards” you with the back of a chair is what I use. But applying a length of very sticky tape is consistently challenging to do while using only one hand. Getting the tape to lay smoothly so you don’t irritate your skin and also putting it exactly where you want it to go is definitely easier with two hands than one.

I have made one modification to Medtronic’s suggested order of insertion steps as an adaptation to working one handed. After inserting and very carefully removing the “serter”, I leave the insertion needle in place while I slowly & gently remove the white paper cover to affix the curved adhesive pad on an Enlite’s back end. It’s only after I have applied the rear adhesive pad that I move on to working on removing the insertion needle tower.

I do it this way because I think it may make it a little harder to accidentally pull out the sensor while I am tugging one-handed on that rear adhesive cover. Maybe it makes no difference, but, if nothing else, it makes me happier doing it this way. Probably not worth thinking about if you have someone other than a cat who can help you with that step. :blush:

One final question and slight digression. I would like to ask @swisschocolate and/or @Buckley83 and/or @ anyone else using Enlites outside the U.S., if you have ever spoken about inserting the Enlite in the upper arm with anyone from Medtronic or whomever you work with about CGM/Enlites in your doctor’s office. If so, what did they say?

I’m just looking for some anecdotal confirmation from personal experience on whether or not Medtronic presents a different policy towards CGM insertion sites outside of the U.S. versus inside.

don’t put it in the back of your arm. Put it in the side of the front of your arm. Don’t worry what MM or your doc says!! Put it where it works, and for many, that is in the arm. I’ve posted pics twice before of where I wear it. No other location works worth a crap for me. It’s easy to get WEAK SIGNAL when wearing it the arm, so pump placement is important.

I would never tell MM techs that I have it in my arm. I’ve told m doctor’s office staff (and the doc) that I put it there as they know all about my complaints with the system when I’ve worn it on my abdomen.

I obviously am not “worried”. If I was then I probably wouldn’t do it at all. And, frankly, I have never really gotten any official feedback on this from a human. The only reason I know Medtronic classifies this insertion location as “not indicated” is from reading their docs and watching their vids.

But I am still very curious what sort of external feedback others may or may not be getting. Perhaps its because I don’t get out much? :confused:

So yeah, i cant do it myself either. the putting in is not the problem, but the tape afterwards i cant do on my own. either my mom or my sister have to help me.
My rep did not tell me anything about where to put the sensor, she told me i can put it wherever i inject (except 3cm away from the infusion site). she even encouraged me to use other places when i had struggles with my sensor back in june/july.
Personally i have now decided not to use my arm for a while, as i have noted sensors working better in my buttocks, and they are easier to put in there on my own as well.
my rep told me that sensors work best in fatty tissue, and as i am lean, arms might not work best.
but again, my rep encouraged me to try out different places as arm, belly, buttocks, legs, hips, etc.

I’m not quite clear. Are you saying that, for you, Enlite on the arm did not work as well as other locations? Just asking to clarify.

This is why I nominally target the “back” of my arm, but I’ve never actually gotten a sensor there. The sensors always end up off to outer side of the arm because apparently that is the best I can do on my own.

You mean like this guy does it (at around time 1:45 into the video)? In my case I’m am pretty sure I would really have a hard time getting the overtape on properly … working just myself … if I tried to insert there.

My arm is lean and my wife’s arm is lean. the sensors work great in our arms. we both have fat on our abdomens and I have had numerous failures (for sure, more than 14, since December 2014) when putting sensors there. So much for your rep’s opinion being gospel.

question one: i think that i have noted, that amongst other reasons, the arm might have contributed to my sensors not working properly for 6 days. this, as i have used the place that i am going to explain in question two, for a month now without problems, and after trying the arm again i already had a failure yesterday. so i’ll leave it for now. this might also be addressed to @phoenixbound’s response. while i see that the arm works miraculously well for you, it might not be the best option for me atm.
question two, about where: i dont really put it in the buttocks like that guy in the video, but more on the side where butt and thighs meet…
see picture:

has been working well there for a while and it is easy to put in.

EDIT: if anyone thinks that is me on that picture, it’s not. just a random picture from the internet


Do you think you could have some interference in your house causing this? The only reason I ask is because I’m finding that the range I get on the enlite transmitter is pretty impressive. I often take my pump off when doing heavy work at home and I find I never get a lost/weak signal, even when I am 10-20 metres away from my pump.

the old enlites did have pretty big problems with reach signals, and i experienced the same problems as @irrational_John.
however, with the new transmitter (guardian 2) that problem has been solved for me :relaxed:

20 meters! wow! No way can I get that. Over the last 5 or so years, we have had 4 transmitters between us and none has had that kind of range. we don’t have guardian 2…

20 meters (over 65 U.S. feet) is simply unheard of. If you are using Medtronic’s CGM then I am afraid I find it hard to believe this is actually happening. The signal from their CGM transmitter is simply not that strong. Heck, I’m not sure if even Dexcom users get that kind of connection distance between their sensor and monitor.

Which CGM transmitter are you using? Since you are in Australia my guess is you have a 640G which uses the Guardian Link 2 transmitter whereas in the U.S. we are still using the previous gen MiniLink. But even then the signal strengths should not differ that much. Medtronic does not appear to have changed the design enough to explain an increase in signal strength of that magnitude.

Another possibility is that while the pump and transmitter are actually becoming disconnected, you simply aren’t noticing it. The Guardian 2 will buffer up to 10 hours of CGM data. If the pump and transmitter do disconnect, as soon as they reconnect all that data would be sent to the pump.

For the older pumps such as the 530G and my Paradigm 723, the indicator for whether or not the sensor is connected is on the pump’s home screen. The pic below shows the two status icons to look for.

For the 640G it’s apparently slightly different because the 640G has a color display screen. From what I could find by looking at an online copy of the “System User Guide”, the color of the icon changes. Green means connected (as in the pic below) but the “connection icon appears gray when the Sensor feature is turned on, but the transmitter is not connected or communication with your pump has been lost.”

Are you saying that you can be 20 meters away from your pump for more than 5 minutes and the pump still shows the sensor status as connected? Have you tried having another person check your pump connection status five mintues or more after you have been separated from it?

Sorry, Swiss. I think from now on whenever I see one of your posts my mental image will automatically be of you rising from the water in a bikini with a large red hoop clipped to either side of your waste. :smirk:

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Ok clearly I need to do more testing on this! Last weekend I was working on the roof of our house and I left my pump downstairs on the ground floor, the sensor and pump were definitely connected as my pump alerted my wife downstairs that I was going low.

Yes that is correct. I think the guardian Link 2 transmitter can buffer 6 or 7 days of data as before I got my medtronic pump medtronic rep did a 7 day cgm trial with me. They inserted the sensor and transmitter (no pump connected) and 7 days later I came back and they downloaded the data to a pc.

From what I have experienced the display shows — when the signal is lost, this happens when I am in the bath for example and the sensor is underwater. After the signal has been lost for a longer period of time, maybe around 30 minutes it will then give an alert and error on screen.

This is what I believe but based on your comments I am doubting myself and need to do further testing!

Nope. The Guardian Link buffers data for a max of 10 hours. I base that on the excerpt below which is quoted from a CGM and Sensors FAQ section on the Medtronic Diabetes Australasia web site. Note the bits I italicized.

What happens when the MiniMed® 640G transmitter and insulin pump move out of range?
If the transmitter and insulin pump are too far apart (about 2 metres or 6 feet), an alert will sound and either a “LOST SENSOR SIGNAL” or “SENSOR SIGNAL NOT FOUND” message will appear on the screen. The transmitter holds 10 hours’ worth of memory and if the transmitter and insulin pump are too far apart for longer than 10 hours, reports may have a “data gap” where information is missing during this time period.

I’m not sure what the heck your medtronic rep was up to with that allegedly “7 day cgm trial”. I mean, yes, it was a trial of wearing the do-hickey for 7 days and also of whether the battery is actually going to last 7 days. But the only data they would have gotten would have been the last 10 hours which the transmitter had buffered.

The other aspect of it is that they would have needed to have access to at least one or more meter BG readings during that last 10 hour period to allow them to calibrate and “make sense of” it. Did they also download your BG meter when you came back in 7 days later?

Is there any way you can contact the rep and ask her/him, “Dude??? What the hell was up with that???”

This is the first time I have ever heard of a “trial” of the inserted sensor & transmitter without also carrying the pump. Even if they didn’t want you to use the 640G to pump insulin, you still could have carried one which you could have calibrated and used to monitor your glucose levels. And they could have then downloaded the 640G’s data which would have given them results from the entire 7 day period. :question:

:question: Why would they do this? :question: What the heck were they trying to achieve? :question:

I am now curious as all heck about this. :confused: :scream_cat:

Sorry John I have probably confused things a bit, I have done some research and what I actually did was use the medtronic ipro system. I have done this twice during the past. The transmitter looks the same as the guardian but it’s probably a completely different device that doesn’t even transmit.

You keep a detailed log for 7 days of food/bgl and then these use the bgl levels to calibrate the historic sensor data.

Oh. Yes, that’s a different thingamajig. Never mind. :blush:

I followed your link and went through a bit of the Medtronic training vids to get some idea what it was like. The training vid says you could wear the recorder for 3 to 5 days. But the technology they are using with the “IPro 2” is clearly the old Medtronic Sof-Sensor (aka “the harpoon”), not the Enlite. So I’m not sure how up to date that the training material is.

Do you recall how long ago you went through the process? Do you know which Medtronic CGM sensor you were using, Enlite or Harpoon? (I guess I’m still curious. :blush:)

Did it twice, last time was 6 months ago, before that about two years ago. When I did it 6 months ago the grey inserter with green button was used so I assume it was the enlite sensor. I can’t remember the one from two years ago, I think I looked the other way when the rep was putting the sensor in :scream:

I finally got around to downloading the detailed data from my pump in a “.CSV” (comma separated values) file, opening the file in Google sheets, and then filtering and crunching slightly the Calibration Factors my pump has used over the last not quite 2 weeks.

The results are in the chart below. The raw data, if anyone is interested, follows in a screencap pic below the chart. (I couldn’t think of a easier/better way to include the data in a post. :disappointed:)

I have no recommendations or great insights to offer, just sharing the data. But while I enjoy inserting in an upper arm for a few different reasons, greater sensor life has so far not been one of them … at least for me.

Regardless of whether a sensor was inserted in my abdomen or my arm, the sensitivity of my sensors always seem to deteriorate quickly after about 5 to 6 days. This is indicated by the significant increase in the size of the cal factor the pump comes up with after a calibration.