How sharp does a blade need to be?

My father carried a Swiss Army knife all his life. It had several blades of various sizes, flat and Phillip’s head screwdrivers, tweezers, a plastic tooth pick, bottle opener, and miniature scissors.

A pretty amazing piece of technology, all things considered.

I don’t carry a Swiss Army knife. I find them too bulky to carry in the pocket. But a blade is a handy thing to have around, which is why men started carrying pocket knives once walking around with a sword went out of fashion.

After trying a number of different things over the years, I finally settled on the Husky Box Cutter. It’s the type of thing you find at Home Depot, and a tool more common to construction workers than diabetes educators. It is a flat, folding knife with a belt clip that uses replaceable razor blades. I clip it to the top of my right pants-pocket and I most often use it to open blood glucose meter boxes.

Beyond being light and flat, I really like the fact that I always have a sharp blade without having to go through the whole grinding on a whetstone rigmarole. My mother, a Girl Scout Troop Leader, was always telling me that dull blades are more dangerous than sharp ones. You apparently need more elbow grease to use a dull blade than a sharp one, hence you are more likely to slip and injure yourself.

So why am I writing about blades? Because last night as I drifted off to sleep it occurred to me that CGM sensors are like knife blades; and that the Guardian was a Swiss Army knife with a dull blade while the Dexcom is a box cutter with a razor sharp blade.

Which tool is better to have?

Well, that depends on what you want (or need) to do with it, doesn’t it? If all you need to do is cut, then by all means get the box cutter. On the other hand, a box cutter makes a poor screwdriver, can’t open a bottle, and will never work like scissors.

As I near the end of my recently extended (thanks Secret Santa!) Dexcom trial, I am more and more impressed with how sharp the sensor is. It is dead on. Always. It is fast and responsive. Wearing the two CGMs, I feel more and more like the Guardian is a lumbering, but comfortable, ocean liner. The Dex is a speed boat.

So, despite what I said recently about sticking with the Guardian, am I contemplating a switch? Mmmmmmmmmm…. maybe so. The jury is still out, or is out again. I thought I’d made up my mind to stay with the Girl I brought to the dance, but…

Over the last ten days, every time I take a fingerstick, the Dex is closer. Scary-closer. I haven’t been able to screw up its calibration, even when intentionally trying to do so. That is great for diabetics everywhere, no so much so for me, as now I need to re-write my chapter on CGM calibration. Damn. Oh well, in the long run this makes my life easier too. The Dex is also heaps better when the you-know-what hits the fan, which often happens with me as I have no common sense when it comes to the temptation of carbs.

At first I was convinced I needed a Swiss Army knife, even if it had a dull blade. But do you know what? I mainly use knives to cut with. Why shouldn’t I have the sharpest blade? The truth is, although I like all of the advanced features of the Guardian, I don’t really use them. I mainly wear it for protection from hypos, which my treacherous body does not feel or warn me of.

Guardian lets you pull some pretty amazing data off of the monitor. Dex does not. But she does have some pretty amazing software that can answer every question you have plus twenty more you didn’t even think to ask.

I still dither about the lack of predictive alarms, but the flow of highly accurate, responsive blood sugar information may trump this worry. Right now, the Dex often alerts me to trouble before the Guardian’s predictive alarms do.

I’m also falling for her big blue eyes. That large, easy to read screen is something a guy could really get used to. Pressing a button for info isn’t really that bad, and is probably the only physical exercise I get. Changing the alarm thresholds is simple, given the Reader’s Digest Style menus on the Dex, but I know I’ll forget some night and lose sleep with nuisance alarms or forget to change back in the morning and run around high half the day.

So… I have not made up my mind. Not yet. I’ve got another sensor coming. I’m going to try it monotherapy: I’m going to give my Guardian a week off and see what life is like just living with Dex.

I carry a box cutter because I need a blade far more often than I need a screwdriver. Or a bottle opener. Or tweezers.

Maybe it is OK to view CGM the same way.