I woke up around 1:40 am, hypo and confused. I was trying to get to the backlight on my pump. I knew I had set the CGM graph to not turn itself off (I did that for the sabbath so I wouldn't have to press buttons so much) and that I had figured out that if I just pressed ACT ESC DOWN from any of the main four screens, it should then give me the backlight.
Parenthetically, I had gotten tired of trying to guess how many times I needed to press ESC before getting to the home screen, from which I could press DOWN to get the backlight- there is no way other than getting to the homescreen first or turning on an alarm to get to the backlight generally speaking.
Well, it didn't work, probably because I pressed down first or something. It made some "cancel" noises. It made some beep noises. I wondered if I was drawing a monster with an etch a sketch atnd I started pressing lots of buttons. Still no backlight. Was it broken?
Finally, I got out of bed and turned on the light. I was on the main menu screen. I hit escape and scrolled through the screens. The CGM screen was reading 49; it was on the 6 hour screen and I could see a big drop had happened until about 10:30, when I was still awake and had treated it; it had gone up a bit to about 75, which was when I had fallen asleep. After I fell asleep it fell to about 46 and then rose.
I went to utilities and saw that I had had the threshhold suspend kick in; I guess I turned it off while trying to turn on the backlight (that would be the second time I've done that- the first time I didn't realize what I'd done, thought the suspend feature didn't work, and called the helpline people, who took an hour to tell me I had turned it off myself- oy my sleep).
So I went and ate and treated the hypo and then I scrolled through the screens and noticed something funny. On the Sensor Status Screen, it said Next Cal: 13:46.
That meant that I had entered a calibration at 1:46.
Big problem, I didn't remember entering any calibration at 1:46.
I went to main menu ->sensor-> calibration hist-> and it told me that my most recent calibration had been at 22:38 hours, and was a bg of 75, just like I thought.
But I happen to know that medtronic does not put calibrations in the history until 15 minutes after they've been entered, and it was less than 15 minutes after 1:46. Medtronic doesn't enter them in the history because medtronic doesn't USE them for 15 minutes after they've been entered (to account for the theoretical 15 minute lag, which, btw, is seriously theoretical). This allows it to also have a sort of nice feature which is that if you enter in two calibrations within 15 minutes, it assumes the first one was in error.
That meant I had until 2:01 to enter in a real calibration or it was going to use whatever it was I had entered by accident. I made it just in time. My real calibration says my bg was 69 mg/dl at 2:02 am (no I don't know why that was in time, it shouldn't have been by my calculations).
So, lesson learned, I better turn on the Lock Keypad feature before bedtime. Because next time I might bolus myself by accident. Or enter in another bogus calibration leading to some very bogus numberss turning on a bogus threshhold suspend and making me wonder what the heck was wrong with my CGM.
Dear Medtronic, please please please put a backlight button on your next pump that can be turned on from ANY screen.