On a new site insertion, does anyone know if a sensor will ever recover after giving immediate ??? after two hour start up? This happened at 3AM last night with my two year old - we already had one sensor failure around midnight and had to insert a new sensor, and then the new sensor showed ??? after the two hour start up. I really, really, really didn't want to wake him up again and put another new one on. I toyed with going through another two hour start up time to see if it would come back and we were all so tired, but decided it probably wouldn't work and did another site insertion. Just wondering if anyone has had this experience on a new site insertion, and what happened.
Yes I know - my age is showing.
Got to see old IBM tube computer in Santa Barbara - 1969. Worked on GE 245 - all discrete transistors, diodes etc. As well as early PDP 8, 11, 12, 15 et all. IBm 7040, 1620 411 tabulating machines.
From steam engines to lap top high performance computers and trick advanced cpu chips with branch target cache's, multi pipleline, multi word, multi execution internal units - super scaler operation.
Apologies for walking good folks up.
Oh that's to cute! I am sure it has got to be a way bigger struggle dealing with the little guys and being diabetic. Back in my early days of being diabetic I remember my mom sitting beside my bed spoon feeding me sugar and trying to get me to drink some OJ, "guessing" (no pumps, cgms, or finger sticks back then!) I was low because I was soaking wet with sweat but not running a fever. It's got to be somewhat easier with the Dex when the Dex cooperates! Maybe we need to get Dex to make a unit that shown numbers all the time so parents can set up a "Dex-cam" and be able to view the Dex without needing to go into the childs room and punch buttons! (i'd like to be able to plug my i-pod into my dex at night to wake me up with alerts since I sleep through the alarms!) Good luck with figuring out what works best for Jack and his Dex.
I know I am super lucky to have a CGM. My husband (who works in wireless technologies) and I talk all the time how we would love to have the Dex talk to our phones - or any remote device for that matter. But no we have useless info transmitted - where did you go for dinner? - but not for medical stuff. We always keep hoping for the "Steve Jobs" of diabetes.
People I know complain about the Dex, but I always say SOME information is better than NO information.
Thank you Jim for all your good info on the ???. I just finished my first box of sensors and have had it with dexcom from all the ??? readings. I do insert at night, and wait until morning to start the sensor, but usually within the first few days i get the ??? and stays for hours and hours. My last sensor did ??? all day yesterday and then 'sensor failed' this morning.
Imust admit, I'm not aware of where my cell phone was and how much RF is in the house, but will from now on, do you fridge trick and sit outside and hope that it will recalibrate and start working correctly.
These sensors are expensive so it's quite annoying having them disrupt this easily.
Thank you for comments.
For reasons that escape me; I found it was wise to force disconnect on receiver - put in fridge or cover alumin foil. I would then move to a different environment, and I would see after about 1/2 hour, the ??? would drop and then unit would read a value that matched caveman machine ( +/- 10 points) indicating that sensor was in order. I have done this about 5 times.
Somehow the receiver gets latched up and hangs onto bad values longer than it should and disconnecting link as indicated seems to free things up.
Originally, I used to think ??? was a sign of bad sensors. Today; I am not sure.
Dexcom's advise is one should wait to see if it clears. My experience says about 1/2 hour in quiet RF environment after link dropped/recovered in clean RF environment clears ???.
So far I only have had one sensor recently that really was not working well after stopping and starting. There was no sensor error message while resetting on 2 hours. There was no ??? during initialization. AFter up and running, it struck me sensor was off, so I replaced it and found issues under the sensor platform where I had bled a little and fluids drifted under the transmitter contacts.
I am unclear but the steps I mention so far have got sensors drop ??? after 1/2 hour. For some reason, my impression is that once linked receiver declares the ???; it gets latched on hard unless link dropped and then linked back up in an environment sans no RF Traffic. And in fact it will hang for hours otherwise.
somehow, in noisey rf environment keeps the ??? test period extended - hours?
The only other solid data is that my unit works great in my car, out with jack rabbits in mohave and sage brush and around vacant lots , open fields etc. ( and out of line of site of Point Hueneme Military base and airfield.
some more data and ideas on dexcom and wireless link.
1. if you live in freestanding newer home that has aluminum barrier material
on outside structure, cross interferene in home usually - but not all of grief may be greatly reduced. Usually windows that let visible light in also let in all rf in from the neighbourhood. Condos/apartments and older wood structures, the wood is like glass on the windows allowing all rf signals in.
2. closely spaced townhouses/condos/apartments are serious grief time as there really should be at minimum - aluminum barrier sheets between units. Otherwise while thw walls provide appearance of privacy and from networking/rf/rf polution; one is living in glass house. Burglar alarms, wireless routers, baby alarms, wireless cameras, wi/fi-bluetooth and assorted other neat toys all fight and polute the communal living space.
3. trying to seal off this crap after the fact is like relining space lab with the trick aluminized 3/16 thick mylar film insulation. Reduces heat and rf.
4. Dexcom's unit as I understand it, implements a unlicenced low power rf link with an extremely high gain receiver that is even to me very sensitive to any level of signal sneaking around that can easily override the sensor transmitter pair. that probably explains why in super quiet environments, the system works great unhinered while in communal rf swamps, the link is struggling to overcome all the interference. I really believe that more security and error analsys as well as a user created password one can enter when having trouble just like in a house to keep the pests out, changing the locks with ones own new key helps ensure security. on any system where security is critical for safety and security, changing the password/locks is key critical. Using the transmitter serial number only does not seem to be optimal to me.
5. one off the tricks, I use; is to make a aluminized mylar plastin insulation about a foot long enough and sufficient diameter to slip over my arm and enclose the dexcom receiver/near transmitter pair to help exclude the interlopers. Sometimes that helps as a test. othertimes the strength of the interferor will still overcome. As previously indicated whatch where your cell phones are shut-powered down at critcal times.
6. like cell phones this product from my experience suffers from all the same issues as hot and dead zones where for dexcom, you really want to operate in dead zones - opposite to cell phones.
good luck and happy hunting.
Good luck. problem I see is that extra RF floating around while decom has ??? turned on will keep the ??? turned on. Sometimes I hop in car and go down street to open lot ( away from stores -business's) and I will see it repeatedly drop the ??? after 30 to 45 minutes and go back reading. The inital reading after a ??? has in my mind tracked actual body value and good correlation to fingerprick.
ie while Dexcom receiver stalled out displaying ???, transmitter has been clicking along ok. In past I mistakenly assume trhat ??? is bad sensor and replaced. Not the case. Lately, they all were good after recovering where one sensor was sloppy ( not failing) and I replaced it.
As in quiet environment, unit recovers in reasonable time and I remember that Dexcom field service response is just wait and it should recover. Yes in a quiet rf environment and no cell phone transmit punches.
From your comments I suspect you have a lot of Higher energy RF polution sneaking around in your home environment.
Watching how fast the Dexcom receiver relinks after disconnection is clear indication how quiet your rf environment is.
Many times , I find it relinks quickly standing behind my condo front doors I checked that they have metal cores and no measureable leakage on RF smog meter. Elsewhere it can take minutes - 5 to 10 to relink as receiver struggles to relink.
Another sign is when you are sitting peacefully with receiver within 2 feet and linked up, and it suddenly delinks, that in my mind is clear example of a higher power RF blast that just walked thru your air space.
I also meant to point out that these new remote reading power meters really punch out some racket. Some operate on 800 MHZ region and some others operate on 400 Megahertz region. There not supposed to interfere but the chatter out there says something else.