@funk I read a similar statement elsewhere. I don’t use Tandem, so am not knowledgeable of it, nor, apparently, do I understand what qualifies as “iCGM,” though I thought I did. Seems to me an iCGM designation should mean any CGM so designated should work with any pump claiming iCGM compatibility; if not, the designation doesn’t mean anything and no standard exists. I thought Tandem claimed their pumps to be iCGM compatible; and I thought Dexcom G6 and G7 received iCGM status from the FDA. If so, I fail to understand the non-compatibility. Seems either Tandem, Dexcom, or the FDA isn’t telling the truth…or I have a gross misunderstanding of the iCGM designation. It may be there is more to the G7/G7 15-Day difference than the algorithm as Dexcom has claimed. The situation doesn’t impact me currently, but I’d love to hear from anyone that can clarify the situation.
It probably means at least one of two things for Tandem:
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they have to do all the testing to validate the intra-operability between each of their pumps and the FDA cleared 15 day Dexcom sensors. (Doing this testing before the 15 day sensor is cleared by FDA is very risky in case design changes are required by FDA).
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and they may have to file a submission to FDA to get clearance for use with said pumps and sensor. I believe that responsibility lies with the pump mfr. Dexcom’s responsibility is to make sure the modified 15 day sensor works in the same manner as the predicate sensor so the clearance for the 15 day sensor is not specific to any particular AID system. The 15 day sensor clearance states the following:
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The Dexcom G7 15 Day CGM System is also intended to autonomously communicate with digitally connected devices, including automated insulin dosing (AID) systems. The Dexcom G7 15 Day CGM System can be used alone or in conjunction with these digitally connected medical devices for the purpose of managing diabetes.
This does not mean the 15 day sensor is automatically approved for any pump. That is not how FDA regs work. They require all systems to be tested/approved for intra-operability. In certain cases, some of the companion devices could be “bundled” so that only a worst case configuration needs to be tested and submitted to FDA.
I could be wrong here but that is my take.
The sensor has to be able to last ten days…let alone fifteen, regardless of what it’s cleared to do. It’s got to be capable. The G7’s capability is dubious, at best. Perhaps they have changed the battery (which is very small)…but sensors stopping working with multiple excursions offscale seem to be the norm with the G7.
That’s not my experience. I seldom have a sensor failure except the earlier ones that failed to insert the sensor lead. I usually get 10 11/2 days our of a G7.
With the G6 I would get 10 days the 1 out of 3 sensors with failure occurring on day 7 to 8 out of the other 2. This was not everyone’s experience aa some where able to restart sensors lasting as much as 30 days.
One’s anecdotal experience does not necessarily give an accurate picture across the cohort of users.
I just installed a sensor, about fifteen minutes ago. It failed in less than five minutes, with a “Critical: Sensor Failed” message, and alarm. Unfortunately, my anecdotal experience has been as long as I’ve used them, now about 98% failure rate.
I find it impossible to believe that this degree of failure rate is an aberration or is so far off the median as to be a remarkable coincidence of outliers. I suppose there’s always the possibility that all the duds were shipped to one person, and continue to be shipped to that one person, and fail with remarkable consistency. I imagine the possibility is so far removed by degrees of probability and orders of magnitude as to be in the close to the impossible. Certainly far from probable, or even remotely close (one in the billions) to improbable.
So, not fifteen days, but closer to three minutes. Outstanding.
I spent my whole adult life in diagnosing, repairing and even in design if electronic circuitry. None of what I worked with were biomedical electronics.
That said I have enough understanding of biology and chemistry to recognize that the interaction of bodily fluids and the immune system can play a part in CGM sensor function and disfunction.
It is my opinion based on nothing conclusive that your body is rejecting the intrusion of the sensor lead into your body. The problem as I see it is that a doctor/scientist/engineer team would have to take you as a project. Maybe there’s more people who have the same issues with CGMs. That would be helpful, a larger cohort would yield better results. I would volunteer to be in the control group.
Since that kind of research takes money and grant money is currently in short supply, I think that maybe you should try Eversense or just go back to finger sticks.
Of course it does. If Dexcom had to make any design changes in order to make the sensor last 15 days, then that design change - along with all the V&V and clinical testing would have been included in the 510(k) Dexcom submitted to FDA. The challenge is putting the new device into manufacturing - controlling all suppliers for raw materials and parts, training employees in mfg to ensure that all 15 day sensors are manufactured and tested in accordance with the new specs.
I see ample reports from people here and other diabetic sites, boards, and groups, who report sensor wires protruding out the back of the sensor (“looping” I believe). I’ve seen a number of those, and others in which the wire didn’t properly enter the skin. I don’t think that makes me a “project,” but puts me in the same camp as the large numbers of others who experience the same thing. The odds of me being an outlier are too ridiculous to give credence, and there are far, far too many reports by others experiencing the same thing(s).
In the case of the Libre sensors, it’s telling that Abbott just sent out the notice they did, actually admitting to having caused the death of a few users; I’m sure of greater interest are all the ones to which they didn’t admit.
If these failures are so rare, why is Dexcom so spring-loaded to send out replacements. The response to reporting a sensor failure isn’t “oh, really?” but instead, “of course.” It’s expected, because it’s so common, and so frequent. I don’t think I’m an exception at all; one cannot convince me that what I’m experiencing is uncommon…given that I read and hear about so many others who experience the same. Right here on this board, for example.
@Carbless I have come to the conclusion that you have issues with CGMs that should preclude you from using them. Just do finger sticks like we all use to.
As a T2DM i was doing 10 to 14 finger-sticks per day before I convinced my doc that I needed to add rapid meal bolus insuliin to the Basal I was taking. That is also when I got prescribed the G6.
I have told you about the issues that I had with the G6, getting wonky around day 7-8. Some of those doing that would last for 10 days, some actually lasted 10 days.
I had the mechanical problem with the G7s not inserting the sensor lead in the skin. I called Dexcom support and insisted they send a mailer so I could return it. This was the only problem I have had with G7 except one that fell off in the shower.
I reitterate, if you find Decom and Abbott CGMs intolerable STOP USING THEM! Don’t buy their stock. And try to find something else to post about.
@Carbless Adding to @CarlosLuis’s comments, if you have a schedule for flights around the world, the opportunities to try other CGMs or pumps available in Europe and elsewhere may be a possibility for you. An option to be explored anyway. Other than that, as long as your BG stays sufficiently in range then finger sticks seem your best approach, but that’s a personal preference only you can make. I’d also recommend you consider that most folks satisfied with a product don’t write about it, while those with concerns/complaints do. Your perspective that there’s plenty of comments that seemingly prove a high failure rate that should cause manufacturers to stop releasing products or improve them or cause regulating orgs to force such lacks the statistics of the other side. How many products work as advertised, how many were sent out? Literally millions of CGMs get produced; how many complaints of failure have you read? Many here question the reliability, me included, but while I’d like an improved product, I don’t think there are sufficient people experiencing failures or irritations such as yours to warrant drastic change. In fact, evidence and studies indicate change is needed, but the great majority benefit from the products. That said, there’s room for improvements. The number of people like yourself are few and far between, but they certainly exist.
I feel for your situation, but hope you are taking into consideration the impacts of both high and low BGs and their impact to yourself and others. Beyond the personal impacts, which are your decisions to make, the FAA rules are there for a reason, perhaps more restrictive than needed for many. But you’re making decisions not just for yourself, a lot of others are impacted. I don’t know what kind of flying you do, but I and others trust your decisions take our safety into account annd not by your judgements but rather ours…and place it higher than your own valuations. You may disagree, you may have it all under control. We trust you do.
We all hope you find a resolution that works for you!
As just one example, I started using G6 in Dec. 2018. I have used it every day since. In those seven years, i.e. 250 sensors, I have asked for exactly four replacement sensors. And two of those I consider myself responsible for since I yanked them off my arm getting dressed when not using the free overpatch.
I expect to have similar success with the G7 when I am forced to use it, but would like to wait until I can get the 15 day version to cut down on battery waste and because my experience has been that once they become reliable they stay reliable.
I definitely had this issue and others. I just have to be sure I insert where there is less muscle or knots. Really haven’t had an issue since I know those areas are problematic. It kinda makes sense since G7 insertion angle is completely different than G6.
Fortunately for me things are much better and I’m fine with the G7 performance. The first 6 months were rough.