Minimed 530G with Enlite Sensor Trial, Day 1

When Medtronic recently offered me the opportunity to do a free trial of the Minimed 530G with Enlite Sensor, their new pump and continuous glucose monitoring system, I jumped at the chance. (Disclosure: I have to give it back at the end of the trial period, and they have no say over what I write. Right now I wear the Medtronic Paradigm Revel 523, and the Dexcom Platinum G4 CGM.) Not only am I a diabetes dork and self-experimentation enthusiast, but I genuinely am interested in whether I might eventually be interested in switching over. 

I’m planning on writing a series of blog posts about the experience — so let’s start with the basics.

After an initial call last week from Sheryl, my StartRight program contact (StartRight is Medtronic’s new six-month support program for new customers or people upgrading their systems, and seems pretty awesome), I met my trainer, Lindsay, at a coffee shop this morning to get started with the system. 

I’d already checked out some of the gear myself — or, I should say, the packaging, which Medtronic recently redesigned to provide users with a less overwhelming and intimidating initial experience. (Some people had been so overwhelmed when they opened the box that they sent the pump back without even trying it.) So now the pump and CGM come in a special suitcase that you can bring with you to your training session, without having to worry about whether you’ve got what you need. In addition, the boxes themselves have been redesigned to look more like an Apple product than a medical device. For example: 

It’s a good idea, especially when you imagine what it’s like to initially consider going from this:

to this:

 The first important thing to know about the Minimed 530G with Enlite is that it’s an entire integrated system — so that’s what I’ll devote the rest of this post to describing.

One part is the Minimed pump, which is what actually delivers the insulin. (As pumpers know, the pump is not “smart” — it can’t decide dosing itself — but it makes it much easier to customize your basal rates and make precise adjustments.) And the Minimed 530G is also the first insulin pump approved in the US that has “threshold suspend.” I’ll write more about this feature later, but the basic idea is that once you reach a predetermined number — say, 60 mg/dl — the pump will sound an alarm to make sure that you are alert and conscious (in which case you simply clear the alarm). If you do not respond to its alarm, then it will make a very loud noise, and go into “threshold suspend” mode, which means that it will halt the delivery of basal insulin for 2 hours or until you clear the alarm, whichever occurs first. The idea, of course, is to prevent making a low blood sugar worse by pumping in additional insulin. Again, more on this later.

The next part of the system is the Enlite continuous glucose monitoring system, which reads your interstitial glucose levels and transmits them wirelessly to the pump, which will then alarm if you go too high or too low. (As a side note, some insurance providers — hello, CMS! — don’t believe in the value of CGMs because you’re not supposed to actually dose insulin off them. To which I would like to point out an alternate definition of them, provided courtesy of StripSafely.com‘s Bennet Dunlap: by alerting you to severe hypos, they actually can be considered “death avoiders” — which seems to me like a pretty important purpose, and one which Medicare JUST MIGHT WANT TO COVER.) 

But I digress. The third part of the system is Bayer’s Contour Next Link blood glucose meter. This is the blood glucose meter that the FDA has specifically approved as part of the Medtronic system, and it’s pretty cool: when you test your blood sugar on the meter, it automatically logs the number, asks you if it’s before or after a meal (or neither) and sends the information to your pump. The pump then asks you if you would like to use that number to calibrate your continuous monitor (eliminating the need for manual entry) and also puts that number automatically into your “bolus wizard calculator,” which is a tool built into the pump that helps you calculate a proper insulin dose. 

What’s more, one side of the Next Link is actually a USB dongle — which gets me to the fourth part of the system: the CareLink Personal Management Therapy Software. Once you’ve created a CareLink account, you can plug in your dongle (heh), and the software is able to input all the info from not just the blood glucose meter, but from your pump and the continuous glucose monitor as well. You can then view this combined data on a variety of different graphs and overlays (I will write more about it once I’ve played around), and you can share it with your doctor or diabetes educator or anyone else you think might be interested. What’s more, since CareLink is based in the cloud, you can use it on either PCs or Macs (hallelujah!), and it automatically synchs between your devices. 

***An important coverage note: if you are on the Medtronic system and your insurance company says that it will not cover the Bayer strips, talk to your doctor about writing a letter of medical necessity saying that you require those particular strips. If that doesn’t work, contact Medtronic directly and ask them for help/guidance — if you’re on the 530G with Enlite system, there should be a way to get an authorization to get these specific strips. This is also true for people on mail order — if your mail order supplier tries to switch you to a different meter, PLEASE contact Medtronic or your StartRight representative and ask for help. The mail order supplier is supposed to be getting you these particular strips. (With that said, if you don’t want to use the Bayer meter you also can pick a different one and manually input blood glucose values; you just need to get a CareLink dongle, available from Medtronic, to get the data from the pump into your computer.)***

So that’s the basic overview of how the system works. It’s the first — and only — system in the US in which a CGM and pump communicate with each other directly. (Johnson & Johnson has submitted an integrated Animas Vibe pump/Dexcom CGM system to the FDA, but it has not yet been approved, and while Tandem and Dexcom have a similar plan, it’s not yet been submitted.) It’s also the first system in the US to have low threshold suspend. And it’s also the first system where the data from all three components — pump, CGM and blood glucose meter — can be easily displayed in one software management system. And I have to say, as someone who’s spent the past five years or so on a Dexcom CGM, Medtronic pump, and Abbott blood glucose meter, this smooth integration is really, really nice. 

For my next post, I’ll talk about getting started on the system. If you have any specific questions you’d like me to try to answer during the course of this trial, please leave them in the comment section.

Catherine Price

Catherine Price (www.catherine-price.com) was diagnosed with Type 1 diabetes when she was 22 years old. She has written for publications including The Best American Science Catherine Price is a professional journalist who was diagnosed with Type 1 diabetes when she was 22 years old. Her work has been featured in publications including The Best American Science Writing, The New York Times, Popular Science, The Los Angeles Times, The San Francisco Chronicle, The Washington Post Magazine, Salon, Slate, Men’s Journal, Health Magazine, The Oprah Magazine, and Outside, among others. A graduate of Yale and UC Berkeley’s Graduate School of Journalism

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Catherine Price

Catherine Price was diagnosed with Type 1 diabetes when she was 22 years old. She has written for publications including The Best American Science Catherine Price is a professional journalist who was diagnosed with Type 1 diabetes when she was 22 years old. Her work has been featured in publications including The Best American Science Writing, The New York Times, Popular Science, The Los Angeles Times, The San Francisco Chronicle, The Washington Post Magazine, Salon, Slate, Men’s Journal, Health Magazine, The Oprah Magazine, and Outside, among others. A graduate of Yale and UC Berkeley’s Graduate School of Journalism