I wrote in my last post about a Dexcom G7 sensor which for me was only supplying data 97% of the time. That meant that it missed checkins and combined across the entire day it didn’t respond for just over an hour. Mind you, that metric doesn’t capture how long it was offline for each time: when it reconnects it fills the missing data even though the automated insulin delivery (AID) system wasn’t able to act on the data in real time (and with insulin the timing of the doses can make a big difference).
This article is just a follow-up to that now the sensor has aged slightly. I’m still using that sensor, and now on the 7th day I can see it’s currently only getting an 85% realtime capture rate.
This means that for more than 3.5 hours out of the last 24 there’s been silence. The last gap I saw was 20 minutes long.
Even back in the days of G5 I observed that getting below 95% could negatively impact the final TIR/etc. 85% is just ridiculous.
Sensor comparisons
I’m not currently using that G7 to drive my AID system. I’m not prepared to take that risk, and I’ve just left it in to observe.
I’m currently running off a G6 which is on its 3rd day. And just for laughs I also have another G6 which is at 24 days! Anubis transmitters don’t kill off the session at 10 days but are otherwise the same as a standard G6 transmitter. I was using this sensor weeks ago, but left it in as a cross-check (especially as initially I only had it and the G7 – in between I used a standard G6 transmitter on another sensor).
So let’s see what last night’s data looks like…
The G7 sensor is achieving a real-time capture rate of only 85%. The youngest G6 is at 99%. The old G6 is at 98% (although the difference between 98-100% is miniscule).
Sensor readings can occasionally jump a bit. Sometimes due to just physical impedance (“compression lows” are an extreme example). You can see that even the young G6 occasionally jumps a bit. And the very old G6 is well past its prime, jumping up/down occasionally before continuing.
But the 7-day-old G7 is still jumping all over the place. And not consistently providing data. I’d almost prefer that aged G6 sensor (although it’s about to come out).
Just to reiterate: