News broke the other day that Tandem Diabetes had gobbled up 51 patents belonging to Smiths Medical ASD, the folks who made the Deltec Cozmo pump that’s been off the market for almost four years now. Officials from both companies are tight-lipped on what this means, but it seems to imply that future versions of the slick new Tandem t:slim pump might utilize some legacy Cozmo technology…
Meanwhile, we got word in early January that Tandem and the JDRF are working on a dual-chambered infusion pump, and Tandem is already working to eventually integrate its pump with the Dexcom CGM sensor, so the future of this young company (est. 2006) should be an interesting one!
All this recent news makes us wonder: How solid is the first-generation t:slim, which will serve as the foundation for future products? Many in the Diabetes Online Community (DOC) have begun posting day-to-day im
pressions of this new D-device that got FDA approval in late 2011 and hit the market last summer — including our columnist and correspondent Wil Dubois. Here’s Wil’s overview of his experience so far:
I’ve been pumping with the Tandem t:slim, the new Applesque touch-screen insulin pump for more than a month now.
Believe me, I know what you’re thinking… It’s the same thing that’s been on the minds of everyone who doesn’t have this latest gadget but has been googly-eying and drooling over its sleek slender style, so unlike traditional button-interface insulin pumps.
Is there anything special about the t:slim beyond the pretty face? Is the t:slim just about the looks and not really a better breed of insulin pump?
Those are the questions I’ve been mulling myself lately, and what I’m hoping to answer for you now.
So here we go.
First Impressions
Tandem makes a big deal out of the smallness of their pump, claiming it’s the size of a credit card. At roughly two inches by three inches that’s technically true, but what makes a credit card small is its thinness, not its footprint. In reality, t:slim isn’t much slimmer than the competition. T:slim clocks in at 0.6 inches thin while the Animas Ping is 0.76 inches thick.
Is that thin enough to carry the pump in the front pocket of your blue jeans, like in all the Tandem PR shots? Yep. You 
sure can. That’s how I’ve been carrying mine, although it’s only one of many options.
The t:slim is lovely to see and to hold. It feels solid, and well made. The color screen is highly responsive to the touch, and it uses that color intelligently. The pump has no feature allowing you to change the screen brightness, but it’s well optimized for most lighting conditions: The black background keeps it from blinding you at three in the morning, while the icons and lettering are bright and contrasty enough to make the pump easy to read even in bright indoor lighting. Outside in direct sunlight—at least a mile above sea level where I live—the pump can be a little difficult, but not impossible, to read.
I do find the “buttons” on the touch pad to be a hair on the small side for me, and my big fingers sometimes punch the wrong menu or enter the wrong information. Of course, I’m a luddite who only got my first touch-screen device this last summer, so some of my problems here may be lack of experience.
And speaking of touch-screens…
Risking a Butt-Bolus
Police nationwide have been plagued with an epidemic of butt-dialed 911 calls, false alarms caused by people sitting on their cell phones. According to the New York Daily News, New York City’s emergency center receives over 10,000 butt-calls per day. If we can’t keep our phones from calling the cops when we didn’t intend to, what’s to prevent us from being killed by a butt-bolus of 300 units?
As a safety feature, the t:slim needs to be “unlocked” by pressing the only “real” button on the device (on its top) and then tapping three targets on the touch screen in rapid succession. If the screen is touched anywhere else during this process, the pump’s screen goes dark again. The process is easy, and actually—bizarrely—kind of fun. It’s got that Mission-Impossible-electronic-hacking feel to it. It doesn’t slow me down at all when I need to use the pump, and it works; my t:slim hasn’t dialed the New York City police even once since I’ve had it.
Of course, it’s only been a month.
Scrolling = Obsolete
While Medtronic pumps can get data from specially built versions of the old BD, OneTouch, or lately, Bayer meters; OmniPods have a built-in FreeStyle meters; and the Ping talks to its OneTouch meter—the t:slim doesn’t integrate with any BG meter at all. Even before the t:slim box arrived, I was dreading the thought of having to enter BG data manually for corrections, and worried that I might skimp on doing this as often as I should because entering data manually is such a pain.
But what I hadn’t gotten the 4-1-1 on, until I did it myself, was that entering data ain’t what it used to be. The t:slim’s touch pad does away with the need for endless scrolling through a long chain of numbers with an “up” or “down” button. Instead, you just enter whatever number you need. Directly. 1-2-3. Dial-a-bolus.
So yes, data entry is manual, but not in the old sense of clicking incessantly up and down, over and over, till you get to the number you need.
On-The-Fly Meals & Friendly Programming
Entering carbs for a meal is just as fast as entering a BG, and in another time-saver, you can add up your carbs on the fly. The screen used to enter carbs for a meal bolus is itself a calculator, letting you enter the carb count of each individual food item as you
figure it out. The pump keeps a running total for you—no more writing your food math on napkins—so now (maybe) you’ll be able to eat before your food gets cold.
Then, there’s the whole menu setup of the t:slim that clearly got its share of attention during the design process.
There aren’t endless pages of menus to go through, and in most cases nearly all the options appear on a single screen. Again, no scrolling.
A ground-breaking feature of the t:slim is that basal rates, correction factors, carb ratios, and target BGs can be viewed all together in one place called a “profile,” instead of being in four separate places. The pump holds up to six profiles, each of which can have up to 16 time segments, and you can copy an existing profile with a couple of screen taps to make near-duplicate profiles rather than having to re-enter everything from scratch. Whew!
Sadly, like most other pumps on the market, you still must manually switch between profiles. For example, if you have a weekend profile, you’ll have to activate it yourself on Friday night.
I was also frustrated at the extraordinary number of “are you really sure” type of warning screens when taking insulin. To cover a meal and take a correction bolus requires you to navigate through four such confirmation screens. And when I enter an out-of-range blood sugar into the pump, it first asks me if I want to correct it. Of course I want to. Why else would I have entered it in the first friggin’ place?
All Praise IOB
CoZmo fans rejoice! Insulin On Board (IOB) is baaaaaaaaaack!
The t:slim, unlike the rest of the pump pack in recent years, tracks all insulin given, not just insulin for meals. Better still, it displays this info prominently on the home screen where you can check it without even unlocking the pump. My informal poll of a half-dozen new t:slimers found this to be the No. 1 new indispensable feature. We could spend an entire post talking about IOB tracking, and how to use it, but suffice it to say it’s one of those things that once you have it, there’s no going back.
Power Fear
The t:slim is rechargeable. Every other pump I’ve ever worn was battery powered, and carrying a few spare copper-tops was no big deal. But a pump is a life support system. It wouldn’t kill you if your cell phone went dead—OK, for some people it probably would—but can you imagine the terror that would strike your heart if you read “15 minutes of power remain, recharge immediately” on the screen of your insulin pump? What if there were a blackout? What if you were lost in the woods?
Of course, my daily life is full of rechargeable devices: cell phone, iPod, camera, laptop, and razor to name a few; as is my diabetes life with a Dexcom CGM and a r
echargeable glucometer; and they rarely give me trouble.
Tandem recommends that you “top off” the t:slim’s battery daily, and apparently this doesn’t harm the battery’s lifespan. I plug mine in for 15 minutes a day when I’m in the shower, and I don’t think it’s ever gone below 95% since. In theory, the battery lasts for seven days if you get lost in the woods.
And if you’re planning to be in the woods for more than seven days, you can use a charging pack or solar charger. T:slim can be charged from a wall, a computer, or a car with a USB cable—and the gear needed to do all three is included with the pump.
That said, one thing I would fault Tandem for is giving us a plug for the car and a plug for the wall but only one cable. WTF? A quick call to Tandem and a $9.95 charge on my debit card fixed the problem, and I now have a complete backup charging system in my glove box. If I get lost in the woods it will likely be in my Jeep anyway, and if there’s a blackout I can recharge in my driveway.
Make a Cup of Coffee, Read the Newspaper…
One of the worst aspects of the t:slim is its slooooooooooow site change. The pump features a 300-unit bag-like insulin reservoir rather than a syringe. The pump fetches insulin from this bag as needed using micro-pump technology. Tandem touts this as a safety feature as it places a physical barrier between the wearer and a potentially fatal overdose of insulin — but this also limits the speed at which the pump can fill the infusion set tubing.
Are you sitting down? The time it takes to prime a 43” set is… six friggin’ minutes.
Oh well, at least it gives you time to brew your morning coffee, check the weather and your email, and get a manicure. On the bright side of site changes, the t:slim uses the industry standard Luer lock connection, meaning any brand and style of set can be used, except those with proprietary Medtronic Paradigm connections.
My Final Word
Overall, I think the t:slim is a fine device. It’s more than just a garden-variety pump with a pretty high-tech face. Tandem has led the charge back to IOB tracking, has pioneered a new profile-based method of pump programming, minimized menus, eliminated scrolling, designed a truly user-friendly interface, and wrapped it all up in a small box that is generally fun to use. The fact that it looks cool is just icing on the cake.
Yes, there
are things missing and some that Tandem could have done a little better. For one, the computer software that it goes with it is still being held up by the FDA. This probably isn’t a big deal for veteran pumpers, but will be a real headache for newbies trying to sort out their settings with nothing more than long delivery history logs on the pump itself to work with. You can’t predict how long the FDA may take on anything, but Tandem surely could’ve timed this better.
Am I in love? No. Actually, I’m considering abandoning the t:slim. It has nothing to do with the little incident I had with a reservoir, or with the well-publicized scary low that I had that might, or might not, have had anything to do with this pump.
It’s the sheer volume of “are you sure” screens that stand between me and my insulin that’s starting to make this pump feel like more trouble than it’s worth. The Tandem folks tell me that new FDA regulations mandated this level of caution, but it’s tedious, especially when I’m tired. Please… I just want my damn insulin… These numerous caution screens are starting to grate on me.
So I’m thinking about going back to my insulin pen. For real. It never asks me if I’m sure I want the bolus I just dialed up. Not even once.
Much less four times.
Thanks Will.
Delightful read as usual.
I the buzz I hear is Tandem may not have sent the desktop software to the FDA in a timely manner and if that is true then maybe FDA shouldn’t get the ding. Either way is the freaking software gonna work on Mac as well as PC and what flavor of OS? XP and 10.6? How about off the desktop and into the mobile?
I think your last point about usability is really sound. Maybe that is an area where some patient input is needed in the FDA thinking process. Also I wonder how we do that.
… I just want my damn insulin…
Tandem’s software is web based, not desktop software.
From their website:
“t:connect* is our web-based Mac and PC compatible therapy management software that works with most internet browsers.”
Joy
I’m on the other side of the atlantic and am very much looking forward to the t:slim finally getting CE certification for europe. In the meantime, I thank you (and other t:slim users) for your reviews. That last comment really hit home though. I’m still holding on to my Cozmo, partly because when I looked at the Animas Vibe, there seemed to be SO MUCH more button pressing just to get a bolus (or change any parameters). It looks like all pumps are going the way of extra button pressing for safety but seriously, four “are-you-sure” screens? That could lead to missed boluses for forgetting the final “Yes I’m freaking sure!”
They thought of that all ready, don’t worry, the t-slim comes with a “hey! you forgot to finish this bolus!” alert too, so if you zone out before getting through all the “yes, I’m sure screens”, it notices and calls you on your laziness.
The highlight of the “hey you didn’t finish your bolus” alert though, is that when you acknowledge the alarm, it takes you back to the screen you left off on, so you don’t have to input everything again, which is a nice touch.
Tx for the review. Frustrating to realize the extraneous steps to bolus were required by the FDA. Another fail by the FDA to grok life with T1. Of course, insulin can be dangerous but we use it daily the way other people get in their cars and drive. Should drivers be required to press several buttons to deactivate a warning message, “Are you *sure* you want to drive?” every time they get in the car?
Are you sure you would give up the t:slim because of this, Wil? Are you really, REALLY sure?
You have to think about the Will cranky factor… LOL
Scott–No, I’m not really, REALLY sure. Not yet. But here’s the issue: As far as I’m concerned there are two reasons to wear a pump. The first is a theoretical improved accuracy. I say “theoretical,” because while pumps are heaps more accurate than shots, I suspect that in general they far exceed the accuracy of diabetes, the human body, and the human operator. At least for me, anyway, I’m not sure I need THAT much accuracy. The second reason to wear a pump is it used to be move convenient than shots, and that’s the biggie for me. Right now it’s a toss up. The screens are sufficiently annoying that I’m trying to decide if it’s just not more convenient to whip out a pen. And if this is the way all pumps will be in the future, it’s not just a t:slim issue, it’s a pump issue. For impatient, or “cranky” patients like me, pens may be the way of the future (will someone please design me a skinny pen with IOB tracking????). The other side of the coin, that has me on the fence, is that I do very much like to make use of Temp Rates. That’s one place the worst of pumps trumps a Lantus shot. You can’t take away a basal insulin shot.
Will great article. Being a t:slim user myself I agree with everything said.
The part about the several Clicks (touches) to deliver a bolus is annoying. But like you, I heard this was part of the new FDA requirement.
Who knows, maybe all new insulin pumps will have this “safety” feature included too.
Nice piece as usual.
if bolusing takes too long for you, then just use the ‘touch bolus button”… eating 25 grams of carbs… click it 5 times….
50 grams…- click it 10x.
my son’s fav feature – just like the Cozmo….
FYI I turned off the touch bolus on my previous pump and also on the t:slim. I found myself stacking boluses far too often. This was because I didn’t look beforehand to see if there was IOB. I decided the touch bolus was a luxury I couldn’t afford.
Wil, just wondered if there is some sort of problem and you need to change the insulin bag before it’s empty, can you get the insulin left in it out, like you can in a normal cartridge?
Yep, unofficially of course, you just stick the giant syringe back in and suck it back out. Easy peasy.
Great review! I’m a t:slim pumper as well. So far, I’ve really enjoyed it. It’s less of a burden than my old MM 722. The touch screen might not sound like a big deal to most people, but it really doesn’t make my everyday life a little bit easier. And really what more can I ask for?
The personal profiles have truly been a life saver for me over the last few days as well. I was put on prednisone for 9 days (I’m 3 days in right now), and I was able to duplicate my “Normal” profile and tweak all of my settings without worrying about messing up my regular program. Love it! I think this has truly been the best feature I’ve used so far.
Great article – saying that seems redundant.
even more reason to try to keep my cozmo alive longer….
cant wait to see what / when /if the smiths patents are used for
Don’t quote me on this, but I *think* the number of “are you sure” screens is based on the amount of insulin delivered. I just bolused for 10 grams, just under 1.5 units, and I only had to click “Yes” to confirm request, then “deliver” to deliver the insulin. So two “are you sure” screens. I do know there’s the smaller “are you sure” screen that is like in the middle? I see it occasionally but never really paid attention it them. I am now in the “just press the buttons until it says delivering” mode. As much as it might be an annoyance, I think the couple times I might second guess my decision or want to stop the delivery for whatever reason, I’ll be thankful for it.
I was told yesterday by “my” t-slim rep that the software will be out by the end of the month at the latest, so that should soon be a non-issue.
For what its worth, I was also told that the not-yet-in-existence T-slim integrated with a CGM (Dexcom) should be available by the end of next year. I’m already excited about that because trading my MM Paradigm all -in-one pump & CGM system for TWO thingies to carry around and give input to is kind of driving me nuts. I’ll get used to it, but its not something I’m adapting to very easily.
No other pumps come with so many “are you sure” screens, so did the FDA just decide this was a required safety feature and all new pumps have to come with them, or is this just the excuse t-slim is handing out so we don’t blame them?
The smaller screen in the middle only appears for correction boluses. I was bothered by it until I spoked with a Tandem person. They clearly made a mistake with this screen because all other screens with a Yes/Cancel button combination appear with the buttons on the bottom of the screen. So when i first saw this screen it looked like stuff was missing.
With meal boluses there are more confirmation screens. If you choose an extended bolus on the last confirmation screen then they throw in a few more for good measure. I suspect that some of these were an FDA requirement but that some were added by Tendem to ensure FDa gave a green light, I mean who needs a confirmation screen after loading the pump? Who would load it and then NOT resume the insulin delivery. That certainly seems extraneous.
As of Dec.26, I’m back on pens. My pump would say it was giving me insulin, but too often it wasn’t. With the pens, when I take my insulin, I know I got my insulin. Still carrying the pump around for the Bolus Wizard calculator and CGM, but no reservoir. So far, it hasn’t noticed that it still isn’t giving me insulin.
Wil, excellent review as always. I’m really interested to see what Tandem does with thos Cozma patents. I find it funny that Cozmo is now held up as a paragon because I know people used to complain about the number of buttons presses needed on the Cozmo to deliver a bolus. Something ironic about this.
You mentioned the ease of numeric input. But one very important difference with the Tandem is the accuracy. You can set a basal rate or 1.37 units per hour, or bolus 2.58 units. I think this is going to take some getting used to.
I was in hospital recently on huge doses of steroids. Before with my Cozmo and Dexcom 7+ I never managed to really control the blood sugars. With the t:slim and Dexcom G4 combination I was able to keep my blood sugars close to 140 despite taking almost three times as much insulin. I know that part of that success was the ability to move basal rates up or down by 0.01 unit increments. I think parents are going to LOVE this level of accurate delivery.
My 13 year old son wore the Cozmo since he was 5 and could not wait for the T-Slim to be available. This review is incredibly accurate. Overall we love the T- slim and highly recommend this pump. Completely agree about all the advantages and about the LONG time it takes to do a site change as the main disadvantage.
As for the “are you sure” screens, we were told that all new pumps moving forward will have this precaution mandated by the FDA. So this would not be a disadvantage of the T- slim as compared to other pumps.
The T- Slim is a great pump!
I’ve been using the t:slim since September ’12. Previously I used the Medtronic/ Minimed since 1986. The touch screen is great to use and have no problems with the confirmations.
One issue is the size of the display. Being a little vision impaired I have to use a magnifying glass when reloading the pump, especially when I’m tired.
I had a problem with a cartridge. When changed it would throe an stop alarm. T:Slim immediately replaced my supply of cartridges based on the Lot Numbers. Great support and service.
Finally, I wish I had the software. Great pump!
Wil,
Your comparison of pumps versus injections missed what I consider to be the two most significant advantages of pumping. First advantage: variable basal rates to cover such things as the dawn phenomenon, Second advantage: no fighting with the variability of long acting insulin to achieve correct basal rates. As you point out dosage accuracy is a nice effect, too.
Good points both, as is the importance of temp rates when begining to run low!
I’m a MM Paradigm user and am considering switching to the t-slim. After reading several online reviews, one thing is not clear to me. I know the t-slim has a manual calculator built into it’s input screens and that it displays IOB, but does it have a bolus wizard that automatically subtracts iob from a correction (or carb) bolus?