Medtrum - the new low cost CGM solution now being sold

The lifespan of the sensor is pretty good so far. At the moment, the adhesive is holding my Medtrum in place better than the G5 on the other arm, which is cover in Kinesiology tape.

In terms of restarting, I flipped the switch in the app to give 14 days life. That doesn't seem to have caused any issues. What I did find was that on day 8, the transmitter and phone stopped communicating properly, with the battery showing in the app somewhere around 50%. I popped the transmitter off and charged it, which seems to have resolved the issue, however, it causes the transmitter to believe it has a new sensor.

One thing that's become very clear is that in the first week, the readings were on average 7% higher than blood values. So far, five days into the second week, they are reading roughly 5% lower than blood on average, so there is some inconsistency across the time period. For comparison, in the first week, the G5 was, on average, 0.1% lower than bloods. In the second week so far it has been 10.8% higher than bloods. This all has interesting implications for those using these things for closed loop applications.

In terms of placement, they've licensed it for abdominal use, so are well within their rights to complain about arm use...

@Raralalala - I'm not aware of anyone who's been in the early use stages getting 14 days. I managed 11, and it was noticeable that there was a change in performance after 7 days. I'm in the process of writing up some data, but given both Dexcom and Medtrum state a MARD of 9%, it's worth mentioning that in the 11 days of use, Mean Absolute Relative Variation from Blood (an approximation for MARD using a standard fingerprick test in place of a Yellow Springs Instruments venous analyzer) was interesting:

• A6 was 14% while the Dexcom G5 was 10% over the life of the Medtrum sensor
• A6 was 13% while the Dexcom G5 was 9% during the first week

The other thing worth looking at is the Mean Relative Difference from Blood:

• A6 was 5.5% versus Dexcom G5 at 0.1% over the 11 days of the Medtrum sensor
• During the first week, A6 was +7.1% while G5 was -2.1%, meaning the A6 read higher values than the blood reading in most cases, whereas the G5 read lower. Directional can be skewed by one or two big misreadings, it's also worth adding
• During the second week, the A6 was -3.4% and the G5 was +11.1%, suggesting that once you're past the 7 day point with the G5 that its accuracy drops off.

In addition, the readings above or below current blood test stack up as well:

• Week 1, 62.5% of A6 readings were greater than blood tests, while 32.8% of G5 ones were
• In the second week, 50% of A6 readings were greater than blood tests while 58.3% of G5 readings were.

Based on that first sensor I wouldn't want to dose from the A6 over the first seven days of use, but the performance doesn't appear dramatically different from Enlites used with the older medtronic pumps.

LAtest update: http://www.diabettech.com/cgm/medtrum-a6-cgm-a-week-or-two-in-the-life/

The second sensor isn't showing the same level of skew that the first did. It's more mediated. It's not a great deal more accurate though, with the first four days showing a Mean Absolute Relative Variation from Blood of 19.4% on the A6 vs 10.2% on the G5. What I have noticed is that there is a real tail in performance as you approach the next calibration point. I've seen some properly wide values at that point in time.

For what it's worth, the graphs are:

@redditchdiabetic I'm running the most current version of the software on the iPhone. Can't say I've seen a bunch of updates. Unless they're updating the transmitter every time they update the phone software (which I don't believe), then that shouldn't make a lot of difference.

The second sensor seems to have settled into a much more effective tracking of blood/Dexcom than the first did though. That does beg the question about sensor consistency.