Thursday, August 12, 2010

Dropping Knowledge About My Dexcom

I still need to finish my long overdue full review about my Dexcom.  But honestly the thing has been amazing and well my long self-directed job search has been taking up the bulk of my time.  While I know that going the off-grounds route for my post-MBA job will prove to be incredible rewarding does not make networking my butt off on a daily basis any easier.  But enough of the whining, onto some knowledge about the Dexcom.

My one big frustration with my Dexcom has been its uncanny ability to wake me up at 3am proclaiming that I'm about to go into a hypoglycemic coma with nothing but an announcement of LOW on the screen.  The vibrations and beeps are enough to wake the dead; the tones are especially nice when I accidentally hit the Dexcom next to my pillow while I sleep.  Now if my blood sugar was in the 40s or 50s each time the alarm went off during prime sleeping hours I'd be ecstatic.  However, alot of the time the alarm is going off even though my blood sugar is somewhere in the 110 to 130 range.  Getting woken up at 3:30 for no reason = not cool.

Then during a run the other day I had an epiphany.  My blood sugar started to drop quickly and I could feel some of the symptoms of a bad low coming on so I plopped my butt on a bench.  Since I was looking at my Dexcom every 30 seconds waiting for the trend arrow to change (it takes 7 minutes btw) I decided to clip it off of my shorts and put it on the park bench next to me.  Even though I was just inches away from the Dexcom the out of range icon popped into the status box.  Hmmm..... weird.....

At that moment I realized that the sensor for the Dexcom is probably on the back of the device (I have no official knowledge of the engineering specs for the CGM).  So that when the back of the device was laying flat on a solid wood park bench and my sensor site was above the receiver the transmission got lost in space.  when I flipped my Dexcom face-side down it quickly picked up a signal again somewhat confirming my hypothesis.

It then dawned on me that the same thing is probably happening while I sleep on my mattress.  My big ol' butt is making the sensor site higher than the receiver and if the receiver is face up its receiving nothing but transmission from my mattress.  I've noticed when the Dexcom picks up an intermittent signal it can start to do wacky things - which is what I believe was happening each night.  Now that I keep my Dexcom face down on my mattress I'm getting an "illegitimate" low maybe every 3rd or 4th night - way better than being startled awake up to 3 times a night for false lows.  The small change did the trick and now I'm getting much better sleep!


Meghan said...

I have the same problem with my Dexcom - however, I've noticed even with it facing down on the bedside table it STILL screams that I'm about to die if I'm laying on the sensor. I wear it on my stomach and I've learned when it's on the right side, I must sleep on my left and vice versa. Unfortunately, I have never been able to rectify that situation. HATE IT!

Bernard Farrell said...

Thanks for this really useful time, I'll try it starting tonight.