We took a few spare sensors to our last trip to DC. As an experiment, we put two through the TSA X-ray inspection once. Dexcom requests it be kept out of X-ray machines. My expectation was that it would make no difference.
We installed the first one of these two sensors on Monday. it was extraordinarily noisy, and we lost service multiple times in the first 24 hours, to the degree that we had to take it off within 24 hours of install – it is only the second time we have had a sensor fail in the first 24 hours.
We set up the second X-rayed sensor immediately afterwards. The second sensor was noisy from the start, although much less noisy than the first sensor. We have not lost service yet. We will monitor how long it lasts, and compare it with the next sensor, which will not have been through an X-ray machine.
At this stage, I am suspecting that X-rays may affect sensor reliability. I am surprised. What troubles me is that both sensors were noisy. We will know more in a couple of weeks.
OK - the experiment is over. The results possibly point as X-rays as a source of sensor damage.
I already discussed the first sensor: it is extremely noisy, and failed within 24 hours – a very unusual occurrence for us.
The second sensor failed last week after 12 days – but because of adhesive failure. The sensor itself would likely have been good for at least another two days, because it had not yet entered the “very noisy/ frequent signal drop” phase.
At the same time, while its duration was not affected, it always was a bit noisy from day 1. But “a bit noisy”, I mean that every hour or two you would get a noisy data point that is slightly higher or lower for no reason, a behavior that a good sensor does not display (for us) in the first week but that typically appears (for us) after about a week in place. So the second sensor appears to have had, from the get-go, the same signal quality as roughly a week-old sensor.
I am not sure how the sensors were positioned in our backpack. It is possible, even likely, that one sensor was more shielded than the other by other gear in the bag.
It would have been easier for us to diagnose a clear issue with X-rays if the second sensor had failed early, or if it had been much noisier from the start. However, both sensors exhibited some level of deficient behavior from the start. Two sensors are a very small sample – so I am carefully labeling the reuse of this experiment as possibly pointing as X-rays as a source of sensor unreliability.
My personal action conclusion: after this experiment, I will not allow Dexcom sensors to go into an X-ray machine until further results are available. I would love to see further results from others, if anyone wants to try a couple of sensors as we did.
We are in the middle of a 30 day trip with 7 flight segments, and numerous X-Rays of our luggage going into and out of hotels and metro stations (in Russia this is common practice).
After discussing the sensor reliability we have come to no conclusion about reliability and the influence of X-Rays. So far, EH thinks that he’s not noticed a decrease in effectiveness. But we are really unsure. Also, he noted that his BG has been poorly managed, but is that because of us or because of the sensor? Mysteries abound!
From now on we will more closely look at the sensor reliability. He’s just restarted one that was a week old, so a new sensor is on the horizon. And now we’ve got 4 new-but-X-rayed sensors to experiment with. We will report back if we come to any conclusions.
I do the same thing. I did that three times in the past couple of weeks, and we had no problem with it, other than the need to remember to take it back from the inspector as we gather all of our gear after security. Easy to lose something with all the D gear we carry, that they always need to inspect…
I’ve definitely put them through the x-ray loads of times without thinking about it, and I never noticed any problems with the sensors. To be fair, I usually get long life (minimum 2 weeks, sometimes as much as 4), so they may have been on the shorter end of that, but not in a particularly notable way.
The only times I’ve had unreliable sensors have been when it was bloodied or when I used ones over 5 months expired (and those still worked alright for at least a week, just noisier from the get-go).