Did the sensor (En)lite up my life?

By | 5 May, 2011

And so the day has come. I have called an end to 12 days of loyal service from my first Medtronic Enlite CGM sensor. How was it for me? Well…

The much smaller Enlite sensor (attached to the Minilink transmitter)

Overall it was very good. I’ve no real complaints. It seems a good bit of kit that’s an improvement on the old sensors. Not a life changing, swinging from the lampshades, best thing in the world ever improvement, but a good step forward.

Let’s start at the beginning with insertion. This is much improved. It still fires in with a fair amount of force but – I suspect due to the finer, more polished needle – it really doesn’t hurt. It’s still a surprise when it goes in, as it is when anyone fires a bit of metal into your body at speed, but it’s not a painful surprise.  I don’t have the patience to talk you through the whole insertion process, but if you want to see an animated model inserting the Enlite into his beautifully toned, hair free stomach – take a look here, it’s an accurate representation of what I did.

It did feel like 3 hands would have been useful at times as the insertion process and associated stickies were a bit fiddly at times. With the old sensors I was pretty adept at putting them into my back, but I think it’ll be a while before I attempt that with the Enlite, I need to be 100% happy with the process first. I think a bit of practice will sort this out. 

I was a little disappointed that the packaging is bigger than with the previous sensors. In the grand scheme of things, this is a pretty insignificant whinge, but when you’re trying to fit two weeks worth of infusion sets and sensors plus spares in to a bag, it’s a pain. Then every extra centimeter of packaging counts, and they’ve certainly added a few centimeters. I know there are scientists out there who have dedicated decades of their careers to making this wonderful tech, and I also know it’s bigger to accomodate the plastic bit that now hides the previously scary insertion needle, but as a trend, stuff should be getting smaller, not bigger.

The sensor goes in vertically, like a Quickset, which means there’s no more faffing around like there was with the old ones trying to get the exact angle correct, you just whack it in. That’s good. The insertion process felt a bit longer than with the old ones but I think that was because it was new and I wasn’t used to it. A couple more weeks and it’ll be second nature.

The sensors use the same Minilink transmitter, and now come with a sticky bit to secure that to the body. It did seem pretty robust, but I don’t like having any part of the transmitter exposed to catch things on, so I stuck my usual bit of sticky tape over the whole lot anyway.

Once you’re all connected, there’s still the usual 2 hour start up time (although rumour has it this is due to the programming in the Veo pump rather than the sensor, if allowed the sensor would be up and running straight away – I’ve asked for confirmation of that from Medtronic and am awaiting a response). After that 2 hours, it needs calibrating with a blood test. Previously you had to calibrate at that 2 hour point, then again after 6 hours. This one doesn’t require another calibration for 12 hours.

The big question is of course, is it more accurate? The stats say it is. Medtronic reckon its 17% better overall and 26% better when it comes to low blood sugars. That is of course pretty meaningless if you’re a 6 and it says you’re a 10, so in the real world is it actually any better? I’m reluctant to judge it based on one sensor, but yes, it did seem more accurate.

With the old sensors, if they said I was 3.5, I’d usually find I was in the 2’s. When the new one said I was 2.8, I was actually 2.6 so pretty damn close. Equally with highs, it tracked me more accurately all the way up to 16.8 and back again, better than the old sensors. Obviously these extremes of blood sugars were deliberate in order to test the sensor, they in no way reflect insulin/carb errors by the user.

When I had normal control, the readings were more accurate than with the old sensors. The lag between sensor readings and meter readings seems less than the old 20mins. I had very few accuracy issues with the old sensors and had been using them for so long I tended to know when to expect issues, so I wasn’t expecting massive improvements. However, I am impressed in that it does seem more accurate, even for me.  I’d be interested to know what difference the new sensors make for people who struggled with accuracy with the previous sensors.

The Enlite is registered for use for 6 days. On day 6 I turned off the sensor on the pump, disconnected the transmitter, recharged it for 20mins then reconnected to the sensor and started it up again on the pump. It picked up the sensor after the 2 hour warm up, I calibrated it and I was off and running for another 6 days. The sensor was still working perfectly at 12 days, but I pulled it because I don’t like leaving stuff in my body for much longer than that.

Overall, it seems a good step forward with the whole CGM malarkey, of which I am a huge fan.

Category: Kit & equipment Tags: , , ,

About Alison

Diagnosed with Type One in 1983 at the age of four, Alison’s been at this for a while now. She uses Humalog in a combined insulin pump and continuous glucose monitoring system and any blood glucose meter as long as it takes five seconds or less.

8 thoughts on “Did the sensor (En)lite up my life?

  1. Mike

    Sounds great Alison. I’m still enviously peering in through the sweetshop window like a ragged Dickensian urchin, but it’s nice to know these new treats exist all the same.

  2. Tim

    Top write up Alison. So out of ten, how would you score the old and new sensors?

    In other, related, news. I’m going to be trialling CGM for a few weeks in a few month’s time. So gird your collective loins for further CGM write ups.

  3. Alison Post author

    @Tim I was pretty happy with the old sensors so would have given them 7/10 and probably 8.5/10 for the new ones because of improved insertion and accuracy.

  4. katerina

    Nice review! So are you saying that the part that is stuck to your body is bigger that before? After all this time I was expecting at least a 1/3 reduction in size … Oh well I will have to wait for the dexcome 4 to see if they reduced the volume of the transmitter.

  5. Alison Post author

    @katerina No, the actual bit that attaches to the body is the same size, and the bit that goes into the body is significantly smaller, the disposable packaging that the sensor comes in has massively increased in size.

  6. katerina

    Ok thanks. The same is better than bigger but still it is not what I was hoping for, Why- with all this nanotechnology- can’t they make it smaller???

  7. Emma

    Just wondering how you’ve found the sensors you have used since this one.

    I’m on my first Enlite sensor right now and really disappointed. It’s less accurate than the old sensors, and I’ve had false low alarms regularly every night I’ve worn it. And now it seems to be dying after 4 days. I’m really hoping this is just one dud sensor, since the other reviews I’ve read have been positive.

    Also, do you mind me asking what site you use? I wear sensors in my arm, and I wonder whether that’s what’s causing my problems. Sorry for all the questions! I’m finding it harder to get information on these sensors and people’s experiences, since they’re not out in the US.

  8. Alison Post author

    @emma.carey Hi Emma, good questions, I’ve been meaning to write an update for a while but haven’t quite got round to it, I promise I’ll do it soon!

    I’ve found the sensors to be good. Insertion has always been painless. I find the first day to be less reliable than the old sensors, but the following days to be better, especially in low and high ranges. I got one sensor to 12 days. All others have lasted the full 6 days, at which point on half of them I’ve turned off the sensor, removed the transmitter, recharged it, reattached it to the sensor, turned the sensor back on and done “link to sensor”. Two hours later it asks for a calibration. I’ve found the accuracy has tailed off after about 9 days of use.

    If you’re finding the accuracy poor after 4 days, I’d normally try the IT standard of turning the sensor off on the pump, turning it back on again and then doing “link to sensor” so it thinks its a new sensor. That sometimes sorts it for me, although I haven’t tried it with the Enlites before the 6 day mark.

    I’ve never worn a sensor in my arm. I use my back and stomach. With the old Medtronic sensors I found the ones in my back were always more accurate. I haven’t noticed such a great difference in the new ones.

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