Wednesday, September 12, 2007

So What's Not to Like?

I said I would post more about using the new Guardian instead of my Dexcom Seven. Here it is.

I would say the “honeymoon” with this device is over. I had originally thought that by setting the low threshhold to 100, I could bypass the Guardian’s rather crappy performance on lows. So I have. And most of the time that is OK, I get a low warning that I am 100 or 95, and test and see that I am really in the 70s, so I treat if it’s dropping and forget about it. But that doesn’t always work. Today, for example, I was working and my “Low Predicted” alarm went off. It said I was 120 with one arrow down. I tested and got a 60. Quite the difference there.

Still, though, it caught it. So that’s not the most annoying thing.

The most annoying thing is when a sensor just flakes out and your readings either launch skyward or drop like a rock. Sure, my Dex has done this a handful of times in the 15 months I have had either the STS or the Seven. But I have been using the guardian a little over two weeks and it has happened 3 times.

The first time I was at work. It was the middle of the morning and I had been drifting down after breakfast when I suddenly got a predicted high warning at 170. I tested and was 125. A few minutes later Guardian said I was 190. Then 225, then 300 in the next half hour. I tested again. 122. I entered this value on the Guardian, which by now had me in 400+ range, and promptly got a CAL ERROR and a request for a new reading. Now, when Guardian thinks you have a CAL ERROR and asks for another reading, it doesn’t really mean it. If you give it that second reading you’re begging for a second cal error and a bad sensor. So instead you wait for your BG to level out if it was weird, and don’t give it a new reading for an hour or so.

So I waited. And waited. Ate lunch, went for a walk, tested two hours after lunch and was 170. OK, let’s tell Guardian. Cal Error. Bad Sensor. Since I’m in a study, I can’t just restart, I do need to change the sensor. Which is at home in the fridge. Big PITA.

The second time, I was in bed. It was not quite one in the morning, and I got a predicted low warning. I tested and was 130, right where I want to be at night. A few minutes later a high warning. Then a predicted high warning, then a bunch more high warnings and assorted beeps. I was never over 160 on the meter and pretty level. Again I tried a sync up, and got a cal error. Now it was also beeping for a “Meter BG Now” that I wasn’t going to give it. Needless to say, after that first alarm, I never fully got back to sleep. At 5:15 I finally got out of bed, flung the damn receiver into the closet and shut the door. I could still hear its muffled complaints in my 30 minutes of sleep before morning. I had to call in sick to work that day because I just couldn’t function.

At 9am I let Guardian out of his prison and let him Find Lost Sensor. He happily chugged along for the rest of the time with no problems.

Then a few days ago it happened again. Only this time Guardian thought I was low. I was 156. After an hour or so of bogus below-40 readings, that I refused to dignify by trying to sync up again, I locked Guardian in his closet and went downstairs. Several hours later he was paroled and again behaved himself.

So now I’m thinking that clunky software and carrying a goddam potato clipped to my belt might be a small price to pay for actually getting to use the darn sensor when I want to. If I’m at work when Guardian flakes out, how do I get him out of range for long enough to smack some sense into him? Ask a friend to keep an annoying beeping or vibrating device in their office for a few hours? Put him inside some kind of Faraday cage to block out the signals? Leave him in the ladies room with a “please don’t steal me” post-it note? Or just give up and go back to Dex, who flakes out every few months not every few days.

I’m done with this study in a week and a half. I find now that I’m looking forward to my old clunky but reliable Dex.


Anonymous said...

Lock it in the trunk of the car!

Anonymous said...

I find it funny that people tend to push blame. Ever think you aren't doing it right? Are you calibrating at the right time? Mine's working great. Occasional lost sensor, but otherwise it tracks really well.