#dblogweek – Day 4 – Fantasy diabetes device

For the next week, I’ll be participating in the 3rd Annual Diabetes Blog Week (for more info, click on the banner above). Each day, D-Bloggers will be (mostly) blogging about a common topic but offering their own perspectives.

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My “Fantasy Device”.  Where do I begin?

Today, I’m going to keep my feet firmly planted in reality.  Sure, I’d love a device that can non-invasively track my blood sugars, infuse the proper amounts of super-duper-fast insulin  in my body precisely when it’s needed, keep me from going high, keep me from going low, keep me from interchangeably tacking and taping things to my skin… and make it so small and reliable that I hardly know I’m carrying anything with me at all.

That won’t happen.  I won’t even fantasize about it.

My 2012 Fantasy Device, which should be able to logically enter the marketplace in 2012, is an Integrated Pump and CGM.

But Scott, they already have such a device!  It’s made by Medtronic and is called the Revel.

No, the Revel is not an integrated device, not by my definition.  The Revel is two devices in one case, sharing a display and a couple of buttons, but little more.

So you’re looking for a Closed-Loop system? (Artificial Pancreas)

Again, no.  I’m talking about something that doesn’t even require any more research.  We all agree that delivering insulin based on CGM readings isn’t quite ready for prime time – there are plenty of accuracy issues and mathematical algorithms to deal with.  But there are some ways in which an insulin pump can be integrated with a CGM, in which they share information and display alerts based on the combination of the two.

Take a look at the targets.  My pump has a set of BG targets used to recommend adjustments to my boluses in order to correct a high or low blood sugar.  For simplicity, let’s say I use a single target of 100 mg/dl, all day.  The CGM-side of my pump, however, has a different set of target ranges.  Since people (even without diabetes) always have some level of BG rise after meals, the upper target is, well, higher.  Mine is set artificially high, to 170.  This way, I’ll be alerted if my BG graph looks like I’m scaling the side of a mountain, but not if I’m gracefully strolling over a small hill after a meal.  Unfortunately, with this setup I’ve found myself riding a steady 160 mg/dl for hours without warning.

But it doesn’t have to be this way.  Since my Revel pump/CGM knows how much insulin I have on-board (IOB, also known as “active insulin”) at all times (in theory, anyway), I shouldn’t need to set these levels artificially high.  I’d much rather set my “high” alert at a safer 120 or 130, where I should be without any other influences.  If I’m cruising along at 135 with no IOB, a small correction could be in order and I’d like to know about it.  Hoiwever, when I’m spiking to 150 but I’ve got 4 units of insulin already delivered and at work, the device should know this too, and should be smart enough to leave me alone.  Those 4 units would bring me down safely, and stacking more insulin on top of that could be dangerous.   But it doesn’t.  It makes a prediction of a HIGH BG without considering the entire picture.

Left hand, meet right hand.

When my Revel alerts me to a potential problem, and I need to navigate through to a different screen on the same device to see if it’s really a problem, that irks me.  When a device has a “feature” to tell me when something’s wrong, but I need to take steps to circumvent that feature, it irks me as well.

I’m not asking the pump to deliver insulin based on a CGM reading.  All I’m asking is for it to tell me what I need to know, when I need to know it.  That’s what technology is best suited for – not for being a tease.