4 ms·

Is depletion of the glucose oxidase reagent the limiting factor, versus the ~~17 week estimated battery life? One would expect an item with a 17 week battery th

Is depletion of the glucose oxidase reagent the limiting factor, versus the ~~17 week estimated battery life? One would expect an item with a 17 week battery that also has the glucose oxidase reagent electrode that also lasts ~~17 weeks to have a higher service life - since it does not, I expect the electrode is the limiter and it might have perhaps 30 days? Of course, it has a clock and a limited life to guarantee correct service beyond the 15 day clockout. It will take a better hacker than me to amend the software to explore these electrode limits in a safe manner. One would expect a foreign body might face attack by the body that inexorably acts to cover/passivate this foreign body.

walterbell 2y ago
Some discussion in this 2018 article, https://hackaday.com/2018/12/03/why-is-continuous-glucose-monitoring-so-hard/ https://hackaday.com/2018/12/03/why-is-continuous-glucose-mo... https://idoroseman.com/freestyle-libre-blood-glucose-monitoring-system-teardown/ https://idoroseman.com/freestyle-libre-blood-glucose-monitor... > The sensor life is limited by the amount of chemical coating on the probe and the amount of glucose in the interstitial fluid. It could last longer for a person with low and steady BG than for one with chronically high, so the sensor life is a conservative compromise between battery size, Bluetooth wake cycles, and probe life. If the probe had a larger supply of reactant or its dispersal rate could be slowed, the sensor life could be extended to the battery capacity or the max that the FDA would permit.
- aurizon 2y ago
  Thanks for that +
geor9e 2y ago
On the G4 through G6 generation of Dexcom sensor, there is a trick to restart the timer. So I regularly get about 20 days per sensor. The limiting factor is really just the sticker peeling off. So you have to put some kinesiology tape over the whole thing to keep it on. The other limiting factor is the noise in the data gets bad. By massaging the flesh around the sensor, I can make the noise go away. so i don't think the reactant is running out, i think it's biofilm building up so it can't interact with the interstitial fluid as directly.
- DaFuk 2y ago
  Restart? For the idiots. The smart among us purchased the Anubis transmitter. No restarts required, the sensor stays in until you determine it is no longer accurate or it stops working. The battery is also replaceable.
  - walterbell 2y ago
    Thanks for the pointer. https://bionicwookiee.com/tag/anubis/ https://bionicwookiee.com/tag/anubis/ https://www.loopnlearn.org/anubis/ https://www.loopnlearn.org/anubis/ https://www.facebook.com/groups/310545804061135 https://www.facebook.com/groups/310545804061135
  - xeromal 2y ago
    Idiot seems like a harsh word to use
  - geor9e 2y ago
    That's neat. I'm not sure why you think hearing about this first makes you smart though, or me an idiot. Weird thing to say. I used to get G5 battery changes from a lady on Facebook who would drill and epoxy the transmitter. Once G6 came out she stopped offering it, and I haven't kept up with the underground news. I'll probably order one - $130 for 6 months is about the same as my insurance copay is charging me for transmitters.

walterbell 2y ago

Some discussion in this 2018 article, https://hackaday.com/2018/12/03/why-is-continuous-glucose-monitoring-so-hard/ https://hackaday.com/2018/12/03/why-is-continuous-glucose-mo... https://idoroseman.com/freestyle-libre-blood-glucose-monitoring-system-teardown/ https://idoroseman.com/freestyle-libre-blood-glucose-monitor... > The sensor life is limited by the amount of chemical coating on the probe and the amount of glucose in the interstitial fluid. It could last longer for a person with low and steady BG than for one with chronically high, so the sensor life is a conservative compromise between battery size, Bluetooth wake cycles, and probe life. If the probe had a larger supply of reactant or its dispersal rate could be slowed, the sensor life could be extended to the battery capacity or the max that the FDA would permit.

aurizon 2y ago
Thanks for that +

geor9e 2y ago

On the G4 through G6 generation of Dexcom sensor, there is a trick to restart the timer. So I regularly get about 20 days per sensor. The limiting factor is really just the sticker peeling off. So you have to put some kinesiology tape over the whole thing to keep it on. The other limiting factor is the noise in the data gets bad. By massaging the flesh around the sensor, I can make the noise go away. so i don't think the reactant is running out, i think it's biofilm building up so it can't interact with the interstitial fluid as directly.

DaFuk 2y ago
Restart? For the idiots. The smart among us purchased the Anubis transmitter. No restarts required, the sensor stays in until you determine it is no longer accurate or it stops working. The battery is also replaceable.
- walterbell 2y ago
  Thanks for the pointer. https://bionicwookiee.com/tag/anubis/ https://bionicwookiee.com/tag/anubis/ https://www.loopnlearn.org/anubis/ https://www.loopnlearn.org/anubis/ https://www.facebook.com/groups/310545804061135 https://www.facebook.com/groups/310545804061135
- xeromal 2y ago
  Idiot seems like a harsh word to use
- geor9e 2y ago
  That's neat. I'm not sure why you think hearing about this first makes you smart though, or me an idiot. Weird thing to say. I used to get G5 battery changes from a lady on Facebook who would drill and epoxy the transmitter. Once G6 came out she stopped offering it, and I haven't kept up with the underground news. I'll probably order one - $130 for 6 months is about the same as my insurance copay is charging me for transmitters.