For once in my life, I found out about a new piece of diabetes technology before the rest of my family-full-of-doctors. When I went to my quarterly date with my diabetes nurse over here (2x a year is the endocrinologist, 2x is the diabetes nurse. I'm not such a fan of this endo thing; it requires way too much of my time), I was asked what insulin pump I was using. I proudly showed her my
Paradigm 530G Revel, with its fancy threshold suspend and active insulin indicator, and was shocked when she went 'Oh, you're using the old pump.'
What? You must be mistaken. This is the top of the line, super fancy pump. There isn't anything newer.
Apparently there is. Available in select European countries as of May 2015 (and the Netherlands as of August), the
Minimed 640G is the new kid on the block and it wants to kick ass and take names.
So naturally, I went about getting my hands on it ASAP. Cuz I like to play with fancy new toys that I can't get in the States and are covered by my Dutch insurance. Oh, the excitement! Since according to my Dutch insurance I'm a new pump user, Medtronic sent someone over to my house to train me. I didn't question it, since from putzing around with the 640G I realized I was going to need a lesson or two. Preferably in English.
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The first thing you notice about the 640G is it looks nothing like the previous Minimed insulin pumps. Minimed has had the same pager-like layout and interface since before I started using them in 2001, with some updates to the interface as different features including bolus types (regular, square-wave, and duel-wave), CGMs, and Bolus Wizard were introduced. The basics, though, remained unchanged, and navigating/programming the newest iteration of pump required minimal training (except for using the sensors). Like most technology, the pumps have gotten slightly smaller with each model... until the 640G.
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| The evolution of my insulin pumps, 2009 - present (left to right): MiniMed Paradigm 522 , Paradigm 530G Revel, 640G |
The second thing you notice is it's bigger. And heavy. I'll get to that in a minute.
In my mind, the biggest selling point of the 640G is the predictive suspend ('Smart Guard') feature. You can program a target blood glucose level (BGL), and the pump will automatically suspend when you drop below the target range and trend towards a low BGL. When your BGL starts trending up and re-enters the target zone +2.2 mmol/L, it will turn itself back on. This is an improvement on the threshold suspend introduced with the 530G, which will suspend for 2 hours when you reach a set BGL. This feature is nice, but is reactive rather than preventative, as it is responding to an already-low blood glucose, while the predictive suspend is designed to
prevent the low. This is a huge step closer to a
closed-loop system.
The next awesome thing is that the 640G interfaces with the Bayer Contour Next Link 2.4 glucose meter, which automatically transmits glucose readings to the pump and suggests a correction if needed. The meter prompts you to select the type of reading (fasting, pre-meal, post-meal, other) and you can enter notes. Both the pump and meter will prompt you to take a correction if your blood sugar is high. Have I mentioned the meter is a remote for the pump? That is so freaking cool! My only gripe with the Next Link is that it is larger than other meters on the market (pretty much the same size as the OneTouch Ultra) and the case it comes with has an awkward layout. This is easily fixed by not using the case and/or finding a different one.
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| I took this opportunity to see if my FreeStyle Libre was holding calibration. It is. I'm still madly in love with it, even though it isn't 'smart'. |
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To go along with the facelift, the 640G has a totally new interface. For long-time pump users like me (14 years and counting), this takes some getting used to. On the other hand, the 640G looks a lot less like a pager, so maybe I won't get asked why the hell I'm using something from the 1990's anymore. The menus have many more options (this goes along with the additional features, so I'll forgive it) but aren't always as intuitive as the old interface.
The Easy Bolus feature is managed with only one button (rather than 2) and can only be used while the pump is 'asleep', which worried me a bit since it's how I program (at least) 80% of my boluses. I have been doing it by feel for years, and was not excited at the prospect of having to look at the pump every time I want to take insulin. While the buttons are still textured, there are 7 of them (compared to 5 on previous models), which are different shapes and arranged in a way so it's easy to press the wrong one. More annoyingly, it's really easy to accidentally wake up the pump so Easy Bolus can't be used. It took me a couple days to get used to the new interface, but the transition wasn't as bad as I thought it might be. I still have to look at the screen, but I suspect with time I'll end up closer to the 'program the pump without looking' level.
(UPDATE: I'm still having trouble with the easy bolus. Part of this is that the tones are different than the old pump (and there are more of them, which I'm still trying to get used to), but it's also hard to tell if it actually accepted the bolus without looking at the screen (bah), and it's too easy to accidentally 'wake up' the pump and bypass the easy bolus.)
The 640G is only available in 3.0mL right now. You can use the 1.8mL reservoirs, so that's not a problem, but it does result in a larger pump, which I would rather not have given the already-increased size.
Another thing worth mentioning is the 640G takes a AA battery rather than the AAA that previous Medtronic pumps use. This likely accounts for some of the additional size and weight, as well whatever extra stuff they had to do in order to make the pump waterproof.
A side-by-side comparison of the 530G and the 640G
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My initial impressions are as follows:
Pros:
- The Smart Guard predictive suspend is an exciting step forward for diabetes management. Reviews have been largely positive, and I'm in the process of trying to get my hand on the Guardian 2 transmitter so I can try it out (the US and European sensors transmit on different frequencies, and the Guardian 2 is a new transmitter).
- The preset bolus and basel rate feature is awesome, easy to use, and time saving. I can simply chose a temporary basel of 0.2 units/hr for 2 hours (or whatever I've programmed in) without having to manually set it each time I go out for a run. Similarly, I can quickly select pre-programmed bolus amounts. This feature makes perfect sense and is easy to access through the home screen.
- The introduction of an unlock button helps prevent accidental anything. However, you have to look at the pump to unlock it, since the button changes. In fact, I have to actually look at the pump to do pretty much anything. I know this is an improvement, but I'm set in my ways and this adds yet another step to every process.
- It is now pretty much impossible to accidentally deliver insulin. A bolus requires 5 steps (actually, this is annoying and yet another reason I use easy bolus most of the time):
The bolus stages (from top left): home screen (select 'Bolus'), unlock, bolus menu, select bolus type and amount, deliver bolus, bolus delivery screen
- The interface with the Next Link meter is pretty darn slick and will automatically calibrate your sensor as needed. The fact that it's also a remote makes discreetly taking insulin easier and eliminates rummaging around in your bra or reaching up your skirt when in public.
- It's waterproof! Finally, Medtronic has addressed the only significant difference from the
Animas by making a waterproof insulin pump. While I have no intention of swimming with it, this is great news, as I have murdered a couple pumps with sweat (they're not a huge fan of being stuck in a sweaty sports bra for 4-plus hours) and incidental snow from playing outdoors. That said, I've also had quick dunks that left the old pump no worse for wear, so the waterproof thing isn't that big of a deal for me. Plus, the customer service and warranty of Medtronic is bloody amazing (they have a no-confidence exchange policy, which is exactly what it sounds like), which takes away most of the stress when your pump starts acting weird.
Mildly Annoying:
- For pretty much everything except using easy bolus, I have to remove the pump to use it, otherwise I'm twisting my neck and giving myself a headache trying to read the text upside down. The backlight feature has been eliminated and the new screen is blank when the pump is asleep, so I can't use it as a time piece anymore. I suppose this means it's time to invest in a watch. Medtronic has done a decent job of making the screen readable in direct sun/with glare, but it's not perfect. More importantly, the text size on the 640G is noticeably smaller. I have good eyesight but have a hard time reading some of the menus without taking the pump out. This is one of the only aspects where I think the 640G falls short of previous models.
- The reservoir change interface is even more time-consuming than the 'improved' one of the 530G. The older pump models (through the 522) had only 3 steps in the reservoir change process: rewind, prime reservoir, fill cannula. The 530G added some steps and requires confirmation before moving on to the next: disconnect set from body, automatically prime reservoir, manually prime until you see drops at the end of the cannula, insert set, fill cannula.
The 640G has added even more steps and literally walks you through the set-change process in itty-bitty baby steps. At some point, the prompts are too simple and serve only to make my set change take longer (I can change my set start-to-finish with the 530G in under 3 minutes. The 640G set change took me almost 5). Personally, I feel that the 530G has a good balance between efficiency and idiot-proofing, although my change-resistant ass still prefers the super-basic setup of the 522. We'll see how much the extra-special-stupid-kid reservoir interface prompts piss me off.
Cons:
- The 640G is heavier and larger than the 530G. Much heavier. It's also big enough that it no longer fits easily into my hand. It sticks out about the same, but the belt clip is sub-par and the pump is bulky enough it doesn't fit well into a pocket.
- The belt clip. I was going to put this under the 'mildly annoying' section, but it just keeps disappointing me. The clip feels flimsy (turns out, it actually is flimsy. It's now been repaired twice) and the spring is much weaker than the older models, allowing the pump to shift around on your jeans and fall off easily when bumped. You can no longer clip the pump upside down to the bottom of your shirt - it falls off immediately. This isn't a big con, but I often do this when I'm changing for convenience. I suspect the pump would hit me in the face if I did a handstand. Hold on. I need to go test this.
Yup, the clip fails the 'stay on my pants under gravity load' test. Bummer (and now my cheek hurts a little. I suppose I deserved that).
(26/12/15: After 2 months of continuous use, the belt clip has pissed me off enough that I am seriously considering switching back to the 530G until (unless) I can get my insurance to cover the CGMs. It really is that bad.)
- After a low battery alarm, you only have a couple hours to change it out. This is very different from the older models, which can last over 24 hours with a low battery (obviously, you're not supposed to do that, but I never claimed to do everything the way I'm supposed to). (Note: the battery lasted 3 weeks before it died on me, and I'm not using any of the fancy features. So that's... really crappy. Also, you only get 4 hours of (basic usage, no fancy features) life before it totally dies. This is really not a redeeming quality.)
- The Bayer Next Link 2.4 meter and test strips aren't covered by most insurances in the US (and the meter itself isn't covered by my insurance over here, but the strips are. Go figure).
- The CGM sensors aren't covered by insurance over here since I'm not an actual child (maturity doesn't count, apparently), have long-term good control, and am not trying to get pregnant. This is the first case where I've found a major improvement in US insurances, since my sisters and I have been able to get CGMs covered in the States.
- Only available in Europe (seriously, US FDA, get your shit together).
(NOTE: as of August 2016, the Minimed 630G is available in the USA. This really is the same pump as the 640G, with all the same features, interface, etc. I've been told the belt clip is better, but haven't tested it)
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A couple other things I've noticed after a few days of use:
The 640G feels much bigger than the Paradigm. I know the size difference isn't really that much, but between the weight and larger dimensions, it just seems clunky. I noticed this immediately when I first put it on, and it became even more noticeable when I clipped it to my sports bra when I went bouldering. While the pump didn't bounce around more than than I'm used to, there was no ignoring its presence.
That said, the belt clip is recessed into the pump, which makes it sit flatter. The chafing due to the increased size is a little irritating, and may be more of an issue for those with bigger boobs. The lower profile clip means that the big 'ol box clipped under my shirt is less noticeable, which is definitely a plus, especially since it means that the pump is less visible under my shirt when clipped to a regular bra, thus (mostly) eliminating the third boob effect.
(Top: Minimed 640G, Bottom: Paradigm 530G)
I clip my pump to the back of my shorts when I go for a run (it rubs too much if I put it in my bra), which has potential for annoying bouncing and being super irritating. Given my reservations regarding the belt clip, I was curious to see how the bigger, heavier 640G would handle a run. I was pleasantly surprised to find that it didn't bounce around much more than the 530G, probably once again due to the lower profile of the clip, but the extra weight did pull my shorts down a bit.
UPDATE: I was wrong. The pump bounces around like crazy if there's any sort of slack in your pants and falls out of a sports bra if you bend over. The longer I use it, the more irritating it becomes, to the point where the pump is approaching unusable. I'm going to have to rig something to make it work, because this is very not ok.
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The Minimed 640G has some major improvements over previous models. The new interface takes some getting used to for existing pump users, but all the features are still there, although most of them require some additional steps to access. The pump looks slick but bounces around more than older models. The predictive suspend alone is a reason to upgrade as soon as possible if you have access to the
Enlite CGMs. From a safety standpoint, this is a feature too long coming and should absolutely be taken advantage of. As a stand-alone pump, you can't use many of the new features, so if you can't get your hands on the Next Link meter or the sensors, it's probably not worth the upgrade if insurance doesn't cover 100% of it.
My main gripe with the 640G is its increased weight and really shitty belt clip. The pump feels bulky and heavy, and the annoyance factor doesn't seem to be diminishing over time. Especially given the weight, the belt clip is inadequate and flimsy. Hopefully Medtronic picks up on this and updates the clip (they did this a few years back for the Paradigm models, so it's not unprecedented).
In short, for a new pump user I think the 640G is an excellent choice. It walks you through absolutely every step for pretty much everything you would ever do and suggests when to take a correction for low or high blood sugars. If you use the Bolus Wizard feature, it will even tell you how much to take. In conjunction with the CGM, this is an incredibly powerful tool. For existing pump users, the new features provide valuable insight and can help fine-tune your control. There's a bit of a learning curve, but it's not too bad. As an athlete, there isn't a big difference between the pumps outside of the increased weight, although storing it in a bra is potentially abrasive for people with actual boobs.
(updated 15 November 2015)
(updated (again) 26 November 2015)
