Decision time

While no pump system is perfect, in my opinion, the Snap is the best insulin pump system on the market in the USA today. If I can get my health insurance to cover the bodies, the sets, and the insulin, I’ll retire my t:slim in two seconds and switch to the Snap. Why? Because what matters to me most in an insulin pump is speed and simplicity. And Snap gives me both.

The Snap really is a snap to use. I guess Asante chose a good name for it after all.

Next time: Back to our regularly scheduled diabetes rants.

Should I wish upon a star, I would wish for…

I like a lot of things about the Snap. But are there things it needs to be better? Damn straight. It needs:

To  be able to talk to the Dex G-4 CGM transmitter.

It also needs a meter that talks to it. It would be even better if several different meters talked to it.

It needs to accept a Novolog penfill. Humalog is “off formulary” on many health plans. Including mine.

It needs download capability to a computer. Not for the pumpers, we never bother, but our educators and doctors like to do it.

It needs a brown leather belt case.

All things I’m told Asante is working on. Except the brown leather case.

I also wish they’d fix the few bone-headed menu items we talked about, although the more I used it, the more I got used to how it’s laid out, and I developed workarounds to compensate. Still, I shouldn’t have had to do that. Why couldn’t the entire menu order be user programmable? Like those online surveys where you slide things into the order that’s most important to you. It would let each pumper personalize the Snap’s controls in a way that made the most sense to him or her. No two of us use our pumps the same way. Our diabetes varies. Our diabetes “control” modus operandi varies. Our pumps should be variable, or at least customizable, too.

And to make it the “perfect” pump it also needs:

Basal programing that automatically changes by day of the week.

Corrections that intensify with altitude of blood sugar. I guarantee you that the correction factor that works to fix a blood sugar of 200 won’t be enough to fix a 400.

IOB needs to be on the home screen, along with a time/percentage remaining indicator.

We need an easy place to look up when the next body site change should happen.

It needs faster BGL scrolling, or the ability to scroll BGL numbers by fives.

It needs a well-written and funny user’s manual.

And lastly, it needs a data base of pictures of naked mermaids and cheerleaders. Because who wouldn’t want that?

But other than all of that, it’s a pretty damn good package.

Next week: So will I keep it?

The best things…

The top ten best things about the Snap:

1) Getting insulin for a meal is fast.

2) Filling it with insulin is faster.

3) And you don’t need to fill it up as often as you do with other pumps.

4) It’s lightweight.

5) There are no batteries to change (or spares to carry), nor do you ever need to find a place to plug it in.

6) It’s simple and straightforward to use.

7) Its alarms are loud enough to hear.

8) Bubbles in the tubing are pretty much nonexistent, thanks to the pre-filled reservoirs and automatic tubing fill feature.

9) The text and numbers on the screen are big enough and sharp enough to read easily, and…

10) You can use it in bright sunlight.

Next time: What I’d change if I were King of the Snaps

Where’s the site change reminder? Apparently with Waldo, wherever he is…

This is how it should be: If you fill a cannula a pump knows you’ve just changed your site. That should trigger a reminder that this needs to be done again in either two days, three days, or four days—depending on how sensitive your skin is and how bad your health insurance is.

It should be seamless and automatic. You shouldn’t have to do a fucking thing to make it happen. Furthermore, there should be a quick and easy place to double check when that impending reminder is going to happen. In short, there should be a site-change reminder screen so that when I get ready for bed at night I can check to see if I should leave out a new infusion set for the next morning.

So in a perfect world, a system like that would rate a ten on a scale of one to ten. How does the Snap pump fare in this regard?

I’d give it a one. Or maybe a zero. Or perhaps a negative three. And to add insult to injury, the Snap needs a good site-change tracking, reminder, and status system more than any other pump on the planet because the reservoir changes are completely independent from the site changes. It’s bad enough to try to remember anything that happens on a three-day basis (because it’s never the same day of the week from week to week), but now there are two schedules to take care of. Plus, if you use CGM, it will be in it’s own little site-change schedule, too. I’m surprised no one is getting rich selling diabetes day-planners.

So here’s what I’ve been doing on the Snap, and I hate, hate, hate, hate it. Did I mention that I hate it? I’ve been setting the “Pump Alert.” This is a feature that lets me manually set a countdown alarm. The range of the alert can be as little as six hours or as much as nine days and 18 hours. Don’t ask me how they came up with that range. The hours can only be selected in 6-hour increments.

But getting where you need to be to actually set this alarm is tedious, to say the least. Let me take you through the process. Uh….you might want to brew a cup of strong coffee first.

First, press any button to wake up the pump.

Then, select the “Menu” button.

Next, you need to skip over the following menus:

Bolus

Stop

Basal

Prime

Log Book, and then:

Select the “Set Up” menu.

After that, you need to skip over all of the following menus:

Time

BG Prompt

BG Units

Low Insulin

Notification Timing

Daily Alerts

Auto Off

Beep Volume

BG Log Target

Delivery Limit

Button Guard

Intro Screen

Flashlight

Screen Timeout

And finally, select “Pump Alert.”

That’s 24 button presses, just to get there. Ow. I have a cramp in my thumb. And now I still need to set the alert, both the days and the hours. At least the Snap remembers what I set the last time.

It is, by far, the greatest number of button presses you’ll ever need to do anything on the Snap pump. What the fuck were they thinking?

Now, I do need to mention one other (in theory) cool option. The Snap has a “notification timing” option. This lets you choose between having the pump remind you when the timer expires, no matter what, or choose to have it remind you when you next turn on the pump. This sounds great in theory—no one likes to have a reminder alarm wake them up if they are sleeping in—but using this feature screws up your timing. Once you acknowledge the alarm by telling the pump “OK,” the Snap resets and starts counting down again.

Well, I don’t know about you, but my life is not so precise. What if I get busy and don’t change my site until the next day? Now my site change timer is off. The only way to reset it is to follow that tortuous path laid out above and turn the reminder off, then turn it back on again. And once a timer is running, you can’t stack a second reminder on top of it. If you have a change of heart, or have your infusion set ripped out by a passing door knob, you have to cancel the old alert and then start a new one.

This lack of a proper site reminder sucks, sucks, SUCKS!! It should be automatic with the cannula prime. Or at least it shouldn’t be buried at the bottom of the set-up menu half way to hell, 24 button clicks downstream.

Twenty four clicks for something we need to do every two or three days?

Boooooo…Hisssssss.

Next time: On the other hand, there are areas were the Snap really shines

Status report

Status report

Yesterday we talked about what happens if you take a left turn from the home screen: You end up in Worthless Graphland. But what if you take the other fork in the road? What if you turn right instead? Clicking the right button takes you to a series of screens that give you the current operational status of the pump. There’s some good info in here, even if I might arrange it a bit differently.

The first page tells you when your last bolus was, how much it was, and what kind it was. The next screen gives you your IOB. Does that order make sense to you? I’d rather have the IOB first, as I use it more. But I can see where last bolus can make sense as a priority for some folks. Who among us, half way through a bacon triple cheese burger deluxe with fries, hasn’t had an alarm go off in our heads: Oh my God… Did I remember to take insulin for this meal?

Two clicks to check and you can be back to feeding yer face.

After IOB on the Snap is a temp rate status screen, if you’re running a temp rate. Right now I am, so the Snap is showing me the rate (zero, as I did a super bolus with my breakfast), and the time remaining (11 minutes, as breakfast was quite a while ago). If I weren’t running a temp rate, this screen would show me which basal profile is active and what the current flow rate is.

The next screen shows the amount of insulin remaining in the penfill inside the pump body. Mine shows I’m not-quite running on fumes with 32.85 units remaining. That’ll get me through the day today and through tonight as well. This screen also makes note of the fact that I started this penfill nine days ago, so this body will have lasted me ten days by the time I snap on my last Snap body tomorrow. What will I do ten days after that? You’ll just have to wait to find out.

Next screen over is the pump alert, a feature so sucky I’m dedicating tomorrow’s entire post to it. But briefly, it’s a difficult to set and more difficult to monitor alarm that’s the only thing I can find to function as a site-change reminder (recall that while you can stretch the use of the body to the max, you’d be a fool to do the same with the part of the infusion set that rests on, and inserts through, your skin).

Following the alert screen, there’s a screen that tells you when you last primed the cannula. I hadn’t realized it until now, but I suppose you could use that as an ass-backward site-change reminder, but I hate reminders that you have to remember to check. It rather defeats the purpose, doesn’t it?

The final screen shows the software version, which is meaningless to me, but would probably be of use to their support staff if something totally funky happened to the pump and I had to phone “home” for help.

Next time: Remembering to remember

Pointless data points

Press any button to wake up the Snap, then hit the left button to get to the graph.

The graph?

Oh, yes. The Snap stores and displays a plethora of operational data for you on a graph. At a glance you have your last twelve hours of smart boli, manual boli, meal records and blood sugar readings. But don’t get too excited

This is the stupidest idea of all time.

The display area of the Snap screen is only 3/8ths of an inch tall by 1 and 3/4 inches wide. The Y axis (up and down) displays blood sugar readings from zero to 500, making it only vaguely possible to determine the altitude of  an “+” that marks a fingerstick. The X axis (left to right) holds 12 hours of data. Three almost invisible “tick marks” along the bottom divide the screen into four 3-hour time segments. There isn’t any time readout. It’s a frozen picture. You can’t scroll backwards in time to look at older data, say, last night’s dinner if you were sleeping off a bender and were trying to sort out the night’s blood sugar adventures the morning after

Not that that ever happened to me.

I guess the idea is to give the Snapper a crude tool to study the relationship between meals, boli, and blood sugar. I guess if you didn’t have CGM, and if you did enter every frickin’ blood sugar in the pump, it might have some limited value. For instance, if you went low (and why would you take the time to enter that information into a pump that can do nothing to help you?), and then later—within 12 hours—went and looked at the graph, there’s a remote possibility that it could help you sort out what happened.

That’s a bit of a stretch, isn’t it?

Don’t get me wrong, I love it when any type of data can be displayed in a graphical format, but a graph requires some landscape to display properly, and the Snap screen is woefully small. I think even the folks at Asante know this graph is an embarrassment. They give it only one page in their 167-page user guide. I wanted to give you a quote from that page, maybe something the marketing department slipped in to try to convince us that this is actually a useful feature, but the copy on this one page is as dry as the Dust Bowl. I guess the best advice is the very last line: “Press EXIT from the graph screen to return to the startup screen.”

I predict that’s what you’ll do the one and only time you visit the graph.

I think the Snap graph is a waste of everyone’s time, unless the management is laying the ground work for a place to eventually display trace data from an integrated CGM, in which case the two-button click to get there ain’t bad. But as designed, this graph would make a piss-poor CGM display screen, indeed. With the space between 100 mg/dL and 200 mg/dL on this graph being 3/32ths of an inch, most blood sugar traces will look like flat lines. For comparison, the space between 100 and 200 on the Dex G4 receiver is hair over a quarter inch, more than two-and-a-half time times larger.

On a Snap, with the total vertical space so small, even trend information would be hard to interpret. Does this mean it’s hopeless for a happy marriage between CGM and Snap? No, not really. But like any marriage, the happy couple will either need to remodel their house, or move to a new one. Options might include having the CGM readout only display 50-300, on the theory that outside those ranges (on either end) the shit has hit the fan and “normal” diabetes management is out the window anyway. Or the controller could be re-designed somehow to accommodate a larger screen. Or (((shudder))) they could put in a touch screen. I hope they don’t, as I prefer real buttons. Touch screens require extra steps to unlock them, and suck down more power.

Keep it simple Snap, that’s your strength. We need real options, not a t:slim me-too pump.

Tomorrow: The other side of the graph

Mad Science Two: Up on the rooftop

Pumps get dropped. It’s just part of life for a pump. And pump companies warn you that if your pump gets dropped that something…. bad… could happen. Its delicate circuits might get scrambled. Its moving parts could get jostled. Its casing might get cracked, leaving an opening for water to get it and short-circuit the mother board, causing the mother of all pump failures.

The Snap isn’t drop-proof, but it’s the first pump to quantify the risk of damage after a drop. It has a drop sensor in the body. I guess, more correctly, it’s considered to be an impact sensor. To be honest, I did drop the Snap once, onto a tile bathroom floor at a Holiday Express no less, but the pump didn’t seem to mind. That was about a four-foot drop to a hard surface. I can’t find it in the manual or on their website, but I think one of the Asante people told me they felt the traditional FDA guidelines for pump drops of only a couple of feet were silly, as most dropped pumps are dropped from at least waist height onto hard surfaces, so for an extra measure of safety the Asante engineers shot for a six-foot survivability. And they added the drop sensor, which (perversely) was so innovative it delayed FDA approval of the Snap system for months—further proof that no good deed goes unpunished.

The impact sensor in the Snap will shut down the system if it detects a big enough impact to damage the pump’s parts. Naturally, I wanted to test the drop sensor for myself.

So the first thing I did was to take a used body and hold it as high as I could. I’m about six feet tall and my arms add another couple of feet, so I dropped the body from about eight feet onto my library floor. Now the floor looks like tile, but you need to remember that I’m working-poor, so it’s really self-sticky linoleum tile from Home Depot.

Down plummeted the pump. Ka-thwack! It bounced once. Clunk!

I slipped the Snap out of my pocket and unsnapped the active body. Then I slid the skydiving body into place. Snap! What would happen?

Snap said: “Pump body connected.”

Apparently, it was undamaged. It was time to get more aggressive. Next step, the ladder test.

Down plummeted the pump. Ka-thwack! It bounced once. Clunk!

I clambered down off the ladder, slipped the Snap out of my pocket and unsnapped the active body. Then I slid the skydiving body into place. Snap! What would happen this time?

Snap said: “Pump body connected.”

Apparently, it was still undamaged. OK. No more messing around. Next step, the roof test.

Standing on the very edge of my roof I dangled the hapless pump body over my porch far below. So long, sucka! I dropped it. Down plummeted the pump. Ka-thwack! It bounced once. Clunk! It came to rest in the coiled-up garden hose.

I clambered off the roof, down the ladder, onto the porch, slipped the Snap out of my pocket and unsnapped the active body. Then I slid the skydiving body into place. Snap! What would happen?

Snap said: “Pump body connected.”

Having failed to break the pump by dropping it from as high as I can reach, dropping it from a ladder, and dropping it from the roof of my house, I had only one card left to play. I gave it to a eleven-year-old boy.

My son Rio son grabbed it by the tubing and swung the pump body wildly around his head like biblical David with the sling shot, then let it fly against the house. It impacted with a sickening thud.

If this fails, I thought to myself, I’ll rent a plane and drop the damn thing out the window over a shopping mall parking lot.

But there was no need. Where I had failed, Rio succeeded:

Well, not dropped so much as flung.

Next week: A ’graph or two on graphs

Mine is bigger than yours is

Mine is bigger than yours is

Men spend a lot of time comparing sizes. Who has the bigger salary. Who caught the bigger fish. Whose wife has the bigger breasts. And who has the longer… well, you know. So guys, my infusion set tubing is longer than yours is.

But the funny thing is, I actually thought the opposite was true until I whipped out my handy Stanley 12’ measuring tape this morning.

Here’s the deal: I could have sworn that my previous pump could lie on the floor when I’m standing up naked. OK, that’s probably too much information, but I actually have a point to make here. The Snap pump doesn’t quite make it to the floor from my infusion site. It dangles just a hair above, and pulls on the site.

If you’ve never worn a pump, the sensation of having your site tugged on is an odd one. It doesn’t generally hurt (unless a doorknob grabs the tube while you are moving past it at high speed), but it’s an uncomfortable sensation. Some of it might be more mental than physical. Like when a scuba diver sees bubbles gushing from a shark-severed air hose: Yeah, he’s still breathing for the moment, but he knows it’s not for long. In the same way, our infusion set is our lifeline. Don’t tug on a man’s lifeline.

Now in case you didn’t know it, pretty much all the infusion sets in the world are actually made by the same company, Unomedical, who re-packages them as the various brands we all know. Snap’s are made at Unomedical’s plant in Mexico. Well, that’s not quite right. The Snappers in the Sunnyvale, California, plant make the prism/hub connectors and then send them down to Mexico where Unomedical attaches them to standard infusion tubing and sets, packages them up, and sends them back up to the states. Gotta love the global aspects of diabetes.

The Snap sets come in angled or in 90-degree cannulas, both short and long. The tubing comes in either 43 inch or 23 inch. The 90-degree sets come with the popular disposable “hockey puck” inserter. The angled sets are the manually inserted kind, which is a pity, as I had been using the Inset 30s which have an extremely clever disposable inserter. It’s not that I’m a wimp about inserting an infusions set by hand, but this is easier, faster, more precise, and since I’ve been using them, I’ve had fewer kinked cannulas.

Now… where was I? Oh yes. Because my pump wouldn’t hit the floor, I began wondering if someone was trying to shave a few shekels off the production cost by cheating me of an inch or two.

Thus the Stanley tape measure today.

And guess what? My Snap tubing is a full 44 inches long. I got a bonus inch.

The Inset tubing for my Tandem? 42 inches. They cheated me of an inch, damn them.

But wait a sec, you say, with a full two spare inches and a longer pump to boot, why on earth are you having pump-flat-on-the-floor-while-naked issues? I have no idea. Maybe I’m placing the sets a bit higher on my stomach. Maybe I’m standing up straighter. Maybe I’m naked with the pump on the floor so rarely that I was mistaken in the first place.

But one thing’s for sure. I’m two inches longer than the guy with the Tandem pump.

Next time: Dropping Kittens.

More real math

Snap won’t let me set a 65% temp rate, damn it. It’s making me choose between 63% and 69%. WTF?

Being the insulin-pumping super genius that I am, and being equipped with the latest and greatest in precision pumping equipment, I of course know exactly what I need in this temp rate: and I need precisely 65%. For those of you who have not had enough French Roast this morning, I’m being both facetious and sarcastic here. As we discussed the other day, the precision of our gear is bad, and the precision of our brains is still worse.

Unlike two days ago, today scientific precision is my enemy. Here’s the deal. Snap temp rates can only be set in 0.05-unit increments. So for instance, you could set a temp rate at 0.45u, 0.50u, 0.55u, 0.60u per hour and so forth. Right now, my basal flow is 0.8 units per hour. To get an actual 65% temp rate would require a 0.52 units per hour flow rate. Opps! Snap can’t do that. So I have to choose between rounding down to 0.5u (which would be the 63% temp rate); or rounding up to 0.55u (which would be the 69% temp rate).

So this time Snap is being precise and honest. And frankly, I’m finding that a huge pain in the ass. Life is hard enough without having to re-think everything I’ve done. Most likely, the other pumps let me enter my fantasy temp rate and just round it either up or down under the hood without telling me that’s what they are doing.

And I’m fine with that.

While I understand the purity of math from the engineering perspective, for me this is just one more reminder that I’m swimming in a sea of uncertainty, and that nothing is as real as I’d like to pretend it is.

Just give me my frickin’ 65%! Sometimes being in the dark is a good thing.

Tomorrow: Size really does matter

Why you should keep a skeleton (or an embalmed body) in the closet

The Snap has twice the brains of any other pump in the world because it has a memory chip in the controller and a non-volatile memory chip in each disposable body. There was some practical reason for the body chip, and I don’t recall what it was, but the upshot was that Asante engineers had some spare memory space on it and decided to put it to smart use. Each disposable pump body downloads and stores the controller’s settings the first time they snap together.

What good does that do us?

Well, let’s say that you get a wild hair and decide enter one of those trash-TV ultimate fighting competitions. Hey, it could happen. You step into the Cage of Death and get beat to a bloody pulp in 45 seconds while the crowd goes wild. Unfortunately, you put up such a poor defense that the fight is really too short for good TV, so while sitting on your head, your opponent uses up the extra time by ripping off your pretty blue Snap pump and crushing it in his teeth.

Once you get home from the hospital, you find a FedEx box waiting for you. Inside is a Get-Well-Soon card from the friendly folks at Asante along with a replacement body, this time in Red (because the Black, Pink and Green ones aren’t available just yet). But now you have a problem, being in a body cast and all. And with nine out of ten fingers broken, how on earth will you program your new controller?

Easy-peasy. You get the skeleton out of your closet. Take any dead, used body and plug it into a brand new controller, and you have the option of transferring all of your settings to the new controller. Bada-bing! It’s done. In a Snap.

Of course, if you saved the dead body from day one and dicked around with your settings a hundred times since, your new controller won’t have the current settings, so you might want to be sure to save a new dead body every time you make a serious change in your basal rate or other settings.

Other than self-inflicted stupidity (that’s how I would define being beaten to a pulp on national TV), when else would this feature be useful? Well, shit happens to pumps, even the best cared for ones. Pumps get lost (gasp!), slammed in car doors (horrors!), dropped from roller coasters (oh crap!), cooked in microwaves (oops!), and eaten by sharks. Hey, I bet that’s happened at least once. And pumps, like any other man-made device, sometimes just crap out for no apparent reason. Just like any other pump company, if your controller bites the dust, Asante will quick-ship a replacement to you. But instead of spending hours keying in all your settings into the replacement pump, while mentally beating yourself up for not making a copy of your pump settings the last fourteen times you changed them, you’ll be on your way again with one snap.

Oh. Wait. I’m sorry. That would be two snaps, actually.

You’ll need to snap on the dead body to get the settings moved over, then you need to pull the dead one back off and snap on a new body with fresh insulin onto the newly programmed controller before you’ll be ready to rock and roll.

I like this feature. I’m sick of having to program pumps on tiny screens with little buttons. We seem to be moving backwards in this regard, as the old Cozmos and the first gen Med-T Paradigm pumps could be programed on a PC and the settings then transferred to the pump. Now I confess, on the Cozmo in particular, transferring the data was a pain in the ass, as the infrared reader was a bitch to line up to the pump. (You could always recognize Cozmo pumpers at diabetes conventions because of the bruises on their foreheads from banging their heads on their desktops.) But it still beat the hell out of scrolling through menus and trying to remember what you were doing.

To be fair, the t:slim is quite brilliant as on-pump programing goes, but nothing beats doing it with a mouse and keyboard on a screen with acres of landscape. Well, nothing beats it except not having to do it at all, which is pretty much what Asante has accomplished here, thanks to the unique architecture of their system.

Another forward-looking aspect that’s related to this memory transfer is that it appears that Asante isn’t the kind of company content to let dust collect on its shoes. They’re already talking about the next generation of controllers. The features of the next controller aren’t public knowledge, but we can presume that Novolog and meter compatibility, along with computer downloading are all high on the list. They have, however, announced that if you are a Snapper you’ll always be able to snap-up a next-gen controller for a hundred bucks any time there’s an upgrade. Well, I think they actually said it would be $99, as marketing people think we are stupid enough to believe that 99 dollars sounds soooooooo much cheaper than 100 dollars. And they may be right; there’s a reason gasoline is sold in 9/10 of a cent increments. We can’t get insulin pumps to deliver accurately, but By God a gas pump will if there’s a tenth of a cent to be made.

Now, we could argue all day about whether or not a hundred clams is a fair price for an upgrade, but one thing is for sure: once your credit card runs and the new controller arrives, getting it ready to rock and roll will be a snap.

Tomorrow: Real math; because engineers don’t know any other kind.

By the book and by the numbers

My hosts were astounded. “You actually read the manual? The whole manual?”

Well, yeah. Sure. Of course I did. Poor journalist I’d be if I didn’t do my homework first.

“I bet nobody else outside this building has read the whole manual!” said one management-type admiringly.

“I bet nobody else in the entire universe has read the whole manual,” muttered an engineer into his coffee cup.

Granted, the Asante Snap Insulin Pump User Manual isn’t a great work of literature, and you won’t see it on the New York Times best seller list anytime soon. (I have a dream: Someday, some forward-thinking company will hire me to write an entertaining user guide.) Still, I found some interesting  things in Asante’s 167-page Snap book.

The first thing that intrigued me was that as well as listing the precautions pumpers should take while undergoing various medical procedures (back away from the MRI scanner and no one gets hurt), Asante also details what precautions pump-wearing healthcare workers need to take to protect their gear in the workplace.

Being a most-of-the-time healthcare worker myself, I found this very appealing.

There’s a nice two-page, three-column chart that lays out the details. The first column lists the medical procedure in question. The second column gives pump-safety instructions if the patient is a pumper, and the third column lists pump procedures when the healthcare professional is the pumper.

For instance, ladies, for those you getting a mammogram, Asante advises that the mammogramee disconnect and leave her pump in the dressing room, while leaving her  cannula in place. Meanwhile, the mammogramographer can leave her pump on, so long as she’s behind the shield when she presses the button. Healthcare pumpers who work with MRIs, on the other hand, are cautioned never to enter the scanning room with their pumps on, and laser surgery techs are cautioned that some lasers will cause the pump alarms to go off! Can you imagine the fear that would strike the heart of an innocent sugar-normal getting laser surgery if your air-raid siren accidently went off?

Also of particular interest to me was something nearly hidden in the very back of the manual: The Snap’s delivery accuracy. Here I found some shocking honesty that I’ve rarely seen in pump manuals. Asante shows an analysis of the delivery accuracy of their system at several insulin volumes. The low volume delivery accuracy is depressing, to say the least.

At 0.3 units per hour, the accuracy of the Snap is plus or minus 10%. Oh, snap! Or should I say…Oh, fucking Snap! It’s not too inspiring to think that our basal delivery can vary so much, but at least they are honest and open about it. And for me, anyway, it also calls into question the real value of some other systems that let us set rates out to thousandths of a unit. Bio-usability aside, are we kidding ourselves about the value and accuracy of such minuscule delivery amounts?

More on how Snap stacks up to the competition in that regard in a minute, but first, as pumps are more than the sum of their basal: What about bolus delivery? How accurate is that on a Snap?

It depends on how big a bolus you are taking. For a coma-inducing 25-unit mega dose, it’s accurate to 3%. I guess that’s good enough to guarantee a successful suicide attempt. Perversely, for smaller, more realistic boli, a one-tenth unit bolus is only accurate to plus or minus 27%. Add that error to the error range of your fucking teststrip and it will be clear why seemingly identical circumstances net very different results from day to day. I’m so depressed thinking about it that I want to go drink some cinnamon whiskey, but the carb count on the nutrition label is also subject to the same basic error range.

These numbers are so… awful… that I decided to do some digging. Is this a pump problem or a Snap pump problem? I looked at the published data on the Med-T Revel, t:slim, and OmniPod, and found that… Well, I’m not sure what I found. Generally speaking, all three companies claim a plus or minus 5% accuracy on all basal and meal boli; but the other pump companies list their data differently. It’s like comparing apples to walnuts. For instance, OmniPod only gives their bolus accuracy data for volumes above half a unit, yet the pump is said to be able to deliver boli as small as 0.05 units, which is a volume ten times smaller. What’s the accuracy on that? The folks at OmniPod are mum on that subject

I suspect if we really knew how inaccurate all of our gear is we’d all become drunks. I’m beginning to see that diabetes control is a myth.

Back to Snap. Any other specs of interest? Not really. You can have up to four basal profiles (enough), but you have to switch among them manually. One of the things I miss most about my beloved Cozmo is the fact that it would automatically change basal profiles by day of the week. That let me have a clinic-day profile (more running around) and a writing day profile (more sitting on my ass) without having to remember to change every morning and then change back every evening. Each of the Snap profiles only allows ten steps. Hmmmm…. I know one endo who says that if you need more than four steps you need a new endo, but I’m a believer in smooth-curve basal changes. I have eight steps in my profile and I wouldn’t be insulted if someone felt they needed 24.

Speaking of steps and profiles, you can set eight different insulin-to-carb ratios in a day, but you are only allowed a skimpy three correction factors throughout the day. What were they thinking?

The Snap’s temp rates are limited to 24 hours, which seems sensible. The t:slim, which is currently living on my desk instead of on my pocket, as I’ve been double-checking some items on it as I compare the two systems, let me set a whopping 72-hour temp rate of zero units per hour. Before you wonder why on earth a pump would let you set a deadly temp rate, bear in mind that you might want to run, say, a +50% temp rate for three days when you had the flu. Snap’s temp rates range from 0% to 500% of programmed flow, but won’t actually let you choose the percentage you really want. Say what? That’s confusing and post-worthy by itself, so I’ll dig into that later this week.

By the way, the manual’s final word is that the Snap conducts more than 8 million “redundant safety cross-checks per day for both hardware and software functionality.” As there are only 86,400 seconds in a day, that means the Snap is preforming more than 92 checks a second. Busy little beaver, that Snap.

Well, actually that’s a lie. The part about the last word, not the part about beavers. I took a literary license. The last thing the manual really says is: “This page intentionally left blank.”

Not an ending worthy of great literature.

Next time on LifeAfterDx: Why at least one skeleton in the closet is a good thing

I be, you be, we all be IOB… now I need to pee… (sorry, rhymes tend to run amok)

Now back on Day Two of this little project I mentioned that the Snap pump lets you choose how you want it to track insulin on board, called IOB, or sometimes “active insulin.” And I suggested that you should all send thank you cards to Asante for doing this, and promised to talk in more detail about this feature later. So today is later! But before we get into the details, we need to spend a minute making sure everyone understands what IOB is all about. And it’s all about pancakes.

More specifically, it’s about stacks of pancakes.

Yep, that American gut-busting tradition of piling good things on top of each other is the perfect analogy for one of the most wicked risks of modern insulins: Stacking. Here’s the deal: all of the ’Logs—Humalog, Novolog, Apridralog (OK, I took the liberty of renaming that last one, but it is an analogue insulin)—are classified as rapid-acting insulins.

Hah! Rapid, my ass. Twenty minute onset, two hour peak, four-to-six hour duration of action: What’s rapid about that? Nothing at all. They only get the title by being the fastest of the slow. The insulins that preceded the analogues were called short-acting. ’Logs are faster than short, and so the get the honorary title of rapid, but don’t make the mistake of thinking they come anywhere close to the speed of real insulin in the body of a sugar-normal. Or anywhere close to the speed we dFolk need.

But back to the pancakes. Even if you ate a whole stack of pancakes, it’s likely that you’ll be feeding your face again sometime in the next 4-6 hours. Which also means you’ll take more insulin (at least you’d better had). The problem is, some of the insulin from that first stack of pancakes is still in your system, still active, still able to lower blood sugar. If you test your blood sugar and take insulin for your sugar and a second round of pancakes without considering that some of the earlier insulin is still in play, you can stack the insulin doses, and end up with too much insulin in your body.

Insulin stacking causes spectacular hypos.

The other classic example of stacking crashes is someone checking their BGL and saying, “Wow, I’m too dern high”—forgetting that they took 10 units three hours before—and throwing more fuel on the fire with an hour or more of old insulin action yet to play out.

Traditionally, using syringes or pens, there’s no good way to keep track of when you dosed, and how much insulin may still be in play. [Modern shooters can now use the marvelous RapidCalc Ap on a smart device.] But a pump has the computing power to track this insulin, and take the insulin on board into consideration when crunching the numbers and recommending an insulin dose.

“Wonderful,” you say. “So what’s the problem?” The problem is that no one agrees on the best way to track the active insulin in our bodies. Now the world has changed, but back in the day there were two very different ways to look at IOB, and they were called the Medtronic Way and the Cozmo Way. Medtronic pumps traditionally only counted correction bolus insulin on the theory that any insulin given for food would be perfectly cancelled by our superior carb-counting skills. The Cozmo way realized that was ridiculous, none of us really knows what the fuck we’re doing, and counted all insulin. I confess to being a fan of the Cozmo way of looking at IOB.

In today’s world, OmniPod’s blue-controller uses the Med-T way, as does the Ping. Ironically, the new Med-T pumps no longer use the classic Med-T way. The t:slim uses the Cozmo way, as does, as I understand it, the new black-controller OmniPod pumps. To be honest, I’m not sure how the “new” Roche pump calculates IOB. I tend to forget it’s out there. Have any of you ever seen one in the wild?

I digress. In truth, there are plusses and minuses to either method. And as long as you understand what your system is doing, and it makes sense to you, you’ll be fine. That said, from a clinical perspective, I’ve seen a lot more pumpers get into trouble with the Med-T-type IOB systems than with the Cozmo-type systems. In my view, playing with insulin is playing with fire. And if I’m playing with fire, I really want to see all the fire—not just half of it.

When OmniPod first came out, I was disappointed to learn that they had chosen the Med-T method of IOB tracking. When one of their senior folks came out to set me up to be one of their pump trainers, I asked why they did that. I don’t know if it’s true or not, but the answer I was given was that they polled a bunch of endos and 51% of them preferred the Med-T method. If it was that close, why didn’t you just make it a menu option? I asked.

She just shrugged one shoulder.

Well, the good folks at Asante did just that. In the menu, the choices are called Correction or All. In the Snap pump, this menu is buried in the Smart Bolus setup menu. Go Home>Menu>Bolus Menu>Bolus Setup>Smart Setup>IOB Mode. Getting there takes a lot more button pushes than it looks like, as you have to skip over many other options to reach home plate. But I have no qualms about how deeply it’s buried in the menus because it’s unlikely you’ll ever change it once you set it the way you believe IOB should be tracked.

Just to be clear: Correction = Med-T way; All = Cozmo way.

In addition to the differences in how the pumps of yesterday tracked IOB, there were also big differences in how they reported this tracking to the user. On older Med-T pumps, a lot of this happened under the hood. You couldn’t see it, couldn’t get to it, and couldn’t interact with it. Even on today’s Revel pump, viewing the IOB is no easy task. On the old Cozmo pumps, on the other hand, IOB was center-stage. There was a IOB status screen, and you could even leave the IOB screen as your default when you turned on the pump!

Tandem took a feather from Cozmo’s hat and even upped that ante: the slick Applesque t:slim really shines amongst other modern pumps when it comes to IOB. You don’t even have to fully turn on the pump to see your IOB! Just run your finger across the top of the pump to press the only analog button on the machine, and the unlock screen appears. At the bottom of the unlock screen (and on the main menu as well) is your IOB in a little status banner along the bottom of the screen, both the units in play, and the time remaining.

So how does Snap compare? Not very favorably. Viewing your IOB on the Snap is no snap. It takes three clicks: One to wake the pump, then the right button to get to Status, then the right button again to view your IOB.

 Uh…. Wait a sec. Something is missing here... I see how much insulin is in play, but I don’t see how long it’s going to last. Most of us IOB fans are used to thinking about both volume and duration. Let me give you an example. Let’s say I check my blood sugar and it’s 197 mg/dL. I look at my IOB and see that there’s 1.4 units on board that will last for another 45 minutes. OK, I’m probably safe from a hypo. I might even end up a bit high by the time the inulin runs its course. On the other hand, what if my blood sugar was 109, instead? Oh, crap! I’m gonna crash!

Naturally, I grilled the Snappers about why this key piece of critical insulin guidance data is missing. Their engineers seemed amazed that any of us would care. They viewed it as a house of cards, and pointed out that most pumps reset the countdown if even a tiny amount of insulin is added to the pile. One of them challenged me this way: What if you had, say, 4 units on board with only 30 minutes left? Then you added a quarter of a unit. Now the IOB time re-sets to four hours. It will show you have 4.25 units running over four hours, which is misleading. The large volume is gone in half an hour. Only the little splat left will last longer.

He’s probably right, damn it. But I still don’t like it.

I’m used to making decisions with two facts: volume and time remaining; and I’m getting old enough that I’m getting stuck in my ways and I don’t want to have to change, damn it! Intellectually, I get it. I get that if one variable is misleading, my decisions won’t be the best. But in the trenches, having some indication of time as well as volume is a big help. It puts my IOB into a useful perspective.

The engineers—who clearly don’t have diabetes—also thought it wasn’t that big a deal to check your bolus history if you wanted to know how much came from when. Are they kidding? Who has time for that??!

For me, a common nocturnal ritual (along with brushing my teeth, kissing the boy goodnight, and making sure my alarm clock is set) is to think about my IOB and the time remaining from my dinner bolus while analyzing the risk/benefit ratio of a bedtime correction bolus. Yes, the pump should be able to tell me if a correction is safe or not, but I know things the pump doesn’t know. I also have CGM on my team. So not only do I know my blood sugar, I know my trend. Am I stable? Am I falling? Am I rising? If I combine that knowledge with how much insulin is on board and how long it will last, I’m smarter than my pump. If I’m drifting upwards and the pump thinks a correction is a bad idea, I’ll override it and give myself more insulin anyway. I know I need it. Other times, Mr. Pump might think I could use a correction based on blood sugar and IOB, but I know better because my CGM trace lines are gliding smartly downwards.

The bottom line here is that time does matter. It’s an integral part of the IOB decision-making process in the trenches, where real diabetes therapy decisions take place. While it’s true that a pile of little boli would mess up the true accuracy of a typical IOB timer, I suspect that most of us pumpers don’t really take boli all that often in the first place. If I’m right about that, the conventional timers work fine for most people, and are certainly better than nothing, even if they are a technical house of cards.

But I’m willing to concede that the Asante engineers have a point, so my challenge to them is this: As you guys think the timing is unrealistic; come up with a solution. Don’t ignore the variable of time. Perfect it instead. Why not combine time and volume with an impact percentage measure? Using the example above, it shouldn’t take a rocket scientist to write a piece of code that could tell me:

IOB 4.25 units. 94% exhausted in 30 minutes; 6% exhausted in 4 hours.

I’d be happy, you’d be happy, we’d all be happy. Happy, happy, happy.

Monday: Oh, Snap! I have no idea what I’m going to write about next week… I’d better snap to it and figure out what the Snap I should talk about next.

Mad Science 1: Alien Autopsy

The body had been dead for a few days, but luckily for me, it hadn’t started to decompose yet. I had all the tools I needed for the postmortem assembled and laid out carefully on the sterile field: Pliers, various sizes of screw drivers, a razor knife, and a Dremel tool—just in case things got dicey. Actually, that inventory sounds more like the tools used in a Banana Republic torture chamber than the surgeon’s tools of the trade used in a proper autopsy.

Oh well. And there’s one other difference between this procedure and a proper postmortem: I’ve no interest in the cause of death. We know why the Snap body died. It reached the normal end of its natural life. What I’m really out to discover is not the cause of death, but the cause of life. I’m out to figure out just how the disposable Snap body works in the first place.

Donning a white lab coat, surgical mask, and protective goggles, I centered the bright exam light over the corpse, and got started. First I disconnected the prism-hub tubing connector. Then I pried out the glass Humalog penfill, by some miracle not breaking it in the process. Next, I used a flat wide-bladed screw driver to try to pry apart the sealed seams of the body from the inside of the insulin chamber. To my delight, the seams effortlessly split asunder. The body opened up like a clam shell.

Nurse, put away the Dremel tool, I ordered in my best terse-surgeon voice.

“But Daddy, I’m not a nurse,” objected Rio.

Kids today. No fucking imagination. That’s the whole problem with society.

(((Sigh)))

After accomplishing the hardest part of the autopsy without incident, I proceeded to drop the fucking thing on the floor while moving it to better light to photograph it. Shit! I’ll be pulling small screws and springs out of the bottom of my bare feet for weeks.

Anyway, here’s what most of the pieces, once I put it back together as best as I could, look like:

The first thing I noticed was that it’s powered by an Energizer Bunny battery. Who knew that hyper rabbit had diabetes? I tell you, we are everywhere!

Looking closer, we can see taht the body of the Snap has not one heart, but four: Power, motor, gears, and something new and wonderful. Let’s start with that last one first. Look at this picture:

Across the bottom-left two thirds you can see the plunger driver. Well, what’s left of it after my unfortunate dropping-the-dead incident. To the right and wrapping around the chamber is a strange goo. These are one and the same. The penfill plunger is forced upwards, delivering insulin, by a flexible tube of waxy plastic which in this body is nearly used up, as I drank every drop of insulin it had to offer. I saw these white tube-like structures at their factory, but didn’t realize what they were. They just looked like little lengths of rope to me at the time.

If you look at the housing, you can see that the plunger curls up in a U-shape, like a lazy snake, before beginning its journey upwards. And like a mutant viper, it only has one fang. A single spear-like needle rises out of the tip and skewers the rubber bottom of the penfill to better anchor the system.

What drives this journey? You’ll never believe it. The smallest, cutest little electric motor you’ve even seen:

 Even Stuart Little would find this pint-sized wonder small.

Wait a sec. Isn’t this all a little…umm… primitive for an insulin pump? Where are the brains, for crying out loud? Ah hah! There’s the circuit board and computer stuff, on a thin ribbon, hiding behind the AAA bunny battery:

 The gears I don’t have totally figured out yet, but here they are: A couple of clock-work pieces and something that looks a hell of a lot like an Archimedes screw. Wow, can you get any older-school than the ancient Greeks?

 The circuit board controls the motor, which drives the gears, which turn the Archimedes screw, which moves the snake, which pushes the plunger, which delivers the insulin. Crazy shit! How can this simple and yet elegant system really work without killing me?

Next time: Active insulin and urine. Nothing to get pissed off about.