My requirement for accuracy in the range 80-100mg/dl comes from the way I currently work with the G6 and Omnipod. In practice I only do correction boluses when the G6 is reporting more than 150mg/dl, so in the range 100-150mg/dl I just leave stuff alone; no food without a bolus, no attempt at corrections.
However if the G6 is showing anything in the range 80-100 I look at the trend; up or down. If the trend is down I try to work out whether I need to take corrective action in the form of food. Since the G6 is reading maybe as much as 10 minutes behind my real blood glucose I may well need to take action at 100mg/dl. If it heads to 80 then I need to stop and take action immediately. For this reason the G6 has to be accurate at those numbers; I don’t want to have to stop, do a fingerstick test, and find the result is wildly different from the G6.
Outside that range I don’t much care; above 150mg/dl I do correction boluses off the G6 reading but the correction rate (IU per mg/dl blood glucose change) I have set in the Omnipod is sufficiently low that I don’t think I ever over-correct unless I start stacking corrections.
I have no experience with the Omnipod. My blood sugar often spikes rapidly after eating most carbs and it’s hard for me not to stack insulin because it goes into a range I’m not happy with. My doctor is happy with my pump settings but I wonder if the correction ratio if off. Sometimes my pump will calculate a bolus and then tell me I shouldn’t take any insulin because of IOB. A half hour later, my blood sugar hasn’t dropped a bit and the pump then lets me take insulin.
I get that sometimes with the Omnipod, but not often. The critical variable on the Omnipod is the “insulin action time”, but Insulet have a really crude model of insulin action; I believe they are blocked by Medtronics patents (patents on the obvious, but never mind). If your pump is modelling the insulin according to the data in the freely available (you don’t have to sign an NDA before your read it) package insert then that isn’t the problem.
Your correction ratio might be off. It’s easy to find the correct ratio, well, sort of easy. You don’t eat for 24 hours then ensure you are flatlining (that must be fixed first), then you chug a glucose tablet and carefully do boluses until you are back flatlining. Bernstein describes the procedure without the hard rock allusions. BTW I’m pretty certain that won’t work for T2s, just in case anyone other that us two are reading this.
Well, it happened again. Day 7 into my latest G6 and I figured it was time to do a calibration and get ready to try and extend the life of the sensor. Saturday night my sensor was reading 170 but my finger stick was at 220. I calibrated the sensor through the tslim pump and the same thing happened. The pump would say ‘Calibration accepted’ and a few minutes later, it would ask for a new calibration, and stop giving me readings. Xdrip followed along with the same results.
After an hour and 4 total calibrations, I gave up. I stopped the sensor from the pump and pulled the transmitter from the still inserted sensor. After a half hour I put the transmitter back in and started a new sensor from the pump. Same sensor and same code but didn’t get any warning about not reusing sensors.
After the 2 hour warm up, I started getting readings again and they did and have matched my meter readings since. No calibration errors although I only calibrated one time to check that the readings were matching.
So now I’m even more confused about getting calibration errors 2 sensors in a row after starting to use Xdrip. To the best of my memory, this only happened one other time in 18 months and now twice in a row.
On the positive side, I have shown that pulling the transmitter to reset the sensor does work. Seems a lot easier than the other methods. You just have to have a little patience in getting the transmitter removed.
Just to make sure everyone knows; if you take two test strips and insert one each side at exactly the right place (the place where it is difficult to push the test strips in between the sensor and the transmitter) the transmitter will just pop right out.
For what it’s worth my very newly inserted G6 sensor was working intermittently with xDrip+ until 16:00 today. it then perma-dropped. I killed bluetooth, I rebooted etc. I couldn’t seem to get xDrip+ out of insane-scan mode. So I popped the sensor at 21:10 or so and after a minute or so re-inserted it and rebooted xDrip+. We’ll see what happens; I’ve got the Dexcom receiver in the microwave so that it doesn’t interfere.
I guess that’s an acronym. He’s dead Jim. I’ll let the Dexcom receiver see it then try the @churcr recovery method.
22:00 the Dexcom receiver and xDrip+ had been reporting “sensor errors” (is that what F2D means?). After a while; until a minute or so ago, that was the status, then the Dexcom receiver caught up and filled in all the missing readings, it was outside the microwave but it looks like the microwave doesn’t work, maybe I should turn it on? A couple of minutes later xDrip+ caught up and filled in the same missing readings.
In both cases there is a drop out (no readings) from 21:07 to 21:52. The start was about when I popped the sensor (I did 2IU at that point because I hadn’t had any readings for 5 hours so I did a fingerstick; I have the time from two sources).
So it looks like popping the sensor is another work round for the xDrip+ bugs, at the cost of losing 45 minutes of readings.
The calibration issues are a separate issue; xDrip+ rejected my fingerstick at 21:02 because it was not “sane”, despite the fact that xDrip+ at that moment hadn’t received any readings for around 4 hours and, when it recovered the 21:07 reading it was 179mg/dl while the fingerstick (21:02 according to the meter, 21:04 according to xDrip+ but appearing on the xDrip+ graph at about 21:12) was 186mg/dl.
I don’t use the Dexcom receiver but rather my Tandem pump is used in place of it. What I did was uninstall xdrip from phone first. Then I stopped the sensor from my pump, removed the transmitter, and left it out for a 1/2 hour. After that I put the transmitter back in and started a new sensor from the pump (even though it wasn’t new) and it acted like a new sensor with 2 hour warm up and all.That was 2 days and 8 hours ago and the sensor is still matching fingersticks. Total time of the 2 sessions on this sensor is 9 days and 18 hours so I guess I’ll see what happens later in the day.
I haven’t posted in awhile but thought I should say something. I’m happy but confused about what has been going on. My last sensor install failed with calibration errors after 7 days 10 hours. It was the second sensor that failed out of the box with calibration errors. And both sensors were connected to xdrip!+.
The funny thing is that I restarted the sensor using the method of removing the transmitter. Since then, I have another 7 days out of this sensor with a total of almost 14 1/2 days. And I’m checking my blood sugars with a meter each day and the sensor readings are consistent with the meter readings.
Not sure how much longer I should use this sensor although I’ve seen posts saying that some people go for 20 days. Just seems weird that I was getting calibration errors and Tandem says that means the sensor is bad. But after restarting, I’ve got another 7 days with no problems. Maying the problem is with calibration while running xdrip+. Although I have been verifying the G6 readings with a meter, I have not once tried to calibrate.
I like a lot of things about xdrip but fear I may have to give up on it. I started a new sensor on Sunday, 1/12/20 because I had to go to training on Monday for starting my U200 insulin with my tslim pump. My old sensor was at 15 days and I wanted a fresh one for the insulin switch. While I had left xdrip running, I stopped the old sensor and started the new one with my pump. After the 2 hour warm up, everything seemed ok.
After switching to the U200 on Monday, my blood sugars ran high all day. When I got home from work I decided to compare the Dexcom with my meter and it was off by over 50 points. So I calibrated from my pump. Sadly, I started getting calibration errors for the 3rd sensor in a row since experimenting with xdrip.
Once again, I uninstalled xdrip from my Galaxy s8, removed the transmitter for 30 minutes, and restarted from my tslim. The G6 has been giving me consistent and accurate readings since but I have not reinstalled xdrip.
Hopefully someone out there has some similar experiences that they can share.
When you had xdrip installed, did you have the setting for native checked? When checked, xdrip should show same BG value as receiver/pump. When not checked, xdrip gets “raw” data and determines BG. I use native mode with G6, and get identical readings on xdrip and G6 receiver. Currently using transmitter 8Gxxx. Dexcom is making changes with newer transmitters, that may not let xdrip work as expected, or may need latest release of xdrip.
I’ve found the first 24 hours on the G6 to be unreliable; that’s one of the two reasons why I liked restarting (I’ve stopped doing that with the latest transmitters). I did find that a calibrate during those hours didn’t do anything good for the accuracy in the following days.
In fact I haven’t even tried calibrating at all recently; I just run the sensor uncalibrated until I start getting repeated sensor errors during the day, or the 10 day limit is reached. Using the G6 this way I seem to get very reliable results around 80mg/dl; at least the G6 system consistently agrees with what my body tells me when I start to go below 80.
I gave up a week ago, not because I had any problem with calibration but because I couldn’t handle the regular drop outs in readings. I bought an iPhone and installed the Dexcom app on it along with SugarMate and other stuff. It’s horribly dark ages compared to xDrip+ but it does work.
Yes, I did have Native selected. And xdrip does mirror the readings on my pump (I use that instead of the G6 receiver). It’s my understanding that the 8G has been out for awhile. I’m still using an 81xxx series. But it is nearing the end of its life and I’m not sure I want to hard reset it. I don’t like the idea of not knowing the battery life remaining. My new sensors and transmitters arrived a few days ago. The transmitters are 8G series so I guess I’ll find out soon enough.
Considered that the G6 is FDA approved to use in a closed loop insulin delivery system (Tandem Tslim X2 that I own), I would think that unreliable readings during the first 24 hours wouldn’t be acceptable. I rarely calibrated my G6 and when I did, it would always adjust the readings on my pump.
I don’t have a lot of problems with either the Dexcom app or xdrip dropping off. I have more problems with my meter doing this. I do not like the Dexcom app because it is difficult to see the graph. I liked the graph on xdrip much better plus it would wirelessly send my data to TidePool. Now I have to use the upload app on my computer once a day.
I’m surprised the 8G transmitters are still around. They weren’t in production very long, and had some serious issues with Bluetooth connectivity and accuracy. In my experience, the best results I ever got with the G6 were when I was using an 81 transmitter. I bought another 81 when we were in Maui this past December, after I threw my 8H into the ocean because I was so pissed off at the terrible accuracy I was getting. The current 81 I’m using now, has been fantastic.
I’ve found connectivity as good, perhaps slightly better, than the 80 series with the Dexcom receiver; I never used the 81 series with that receiver.
So far as accuracy is concerned I see no significant change. Indeed now I know how to work with the G6 and know what to believe and what not to believe accuracy is better, but that’s because I’ve learnt how to deal with a system with deficiencies, not because of any change I can detect in the Dexcom system itself.
At present I have consistent connections in a moderately challenging environment (two concrete walls with WiFi blocking rebar) between me an the receiver, this is using both the Dexcom receiver and an iPhone XR with the Dexcom APP. I also had a fully working system in the SFO terminal and (minus the effects of no internet) on an international flight.
What I saw was that xDrip+ could not sustain connections on my previous phone (a BV9500) in noisy environments with any transmitter release. When I started on the 8G on 2019-11-28 with release 0518 the system became less reliable; after a drop out xDrip+ had much greater problems reconnecting. This worsened with 1027 and it seemed that my previous settings were disabled; it looked like 1027 disabled the “minimize scanning” setting and, indeed, most of the settings seemed disabled (they could be set but did nothing).
I could deal with other issues, such as the removal of the preemptive restart (which I don’t really need), but the failure to recover after a connection drop meant the system was unusable.
Surely the other way round? Using the numbers for correction boluses might be dangerous and, indeed, the guidelines say not to use the readings to determine treatments. Using the numbers to increase or decrease insulin delivery by small amounts, however, is harmless so long as the system reads accurately around 80mg/dl because any errors can be corrected later.
It’s not like doing a 90g bolus, which I did on the aforementioned international flight (the airline food problem) then finding I had overestimated; there’s no way to suck the insulin out.
Really not sure what to tell you. My Tandem Tslim pump already has Basil IQ which will stop by insulin delivery based on my G6 readings. And soon to be released in a new system that will enhance Basic IQ with the pump being able to give correction insulin. Also by the readings on the G6.
Of course I’ve read the guidelines several times as well. Whenever I reinstall the G6 app on my phone, I’m forced to read them again. They also say that you should never make any type of correction unless you are getting a BG reading with an up or down arrow. Or if your body doesn’t feel like the readings from the G6 are correct.
I’ve been a type 1 for over 30 years and my body doesn’t always ‘feel’ where my levels are until it’s too late. What good is a blood glucose measuring system that I can’t depend on for accurate readings. Even the meters are allowed to have a +/- 20% range. Thats a big range when you are running low.
Sorry, I do appreciate your input. Just gets frustrating sometimes. I wouldn’t wish this disease on my worse enemy.