Additionally, the Enlite 3 sensor looks much better than Medtronic’s current sensor. Its average error in this pivotal trial relative to lab measurement was 10.3%, needing a minimum of two fingerstick calibrations per day. This is slightly worse than Dexcom’s G5 at ~9% with two calibrations per day, but much better than the previous Enlite at ~14%. Abbott’s FreeStyle Libre has an ~11% error, but it does not require any fingerstick calibrations.
I wish technology writers would use standard measurements so that we consumers/patients could easily compare. The DexCom G4/G5 sensor is rated at 9% mean absolute relative difference or MARD. (A lower number means better accuracy.) The figures copied and pasted above as “relative to lab measurement.” I’m thinking that it’s probably MARD. So it appears that the Dexcom G4/G5 is still more accurate but the Enlite 3 has improved over earlier Med-T sensors.
Back in March, I attended a CarbDM Type 1 Diabetes Summit in San Francisco. The best session was a panel discussion of 6 people who had been (or still were) in the clinical trials for various APs. Two of the doctors who run the clinical trials were there, and the Bigfoot founder was in the audience. Honestly, I was just blown away by the HOPE for the future. And the people that were in the clinical trial for the Medtronic were very happy with it. One young woman mentioned how she loved waking up in range every single morning. I am not a Medtronic fan, but it is only a matter of time until Bigfoot and Ed Damiano’s APs are on the market. Yeah!!!
yes, that was something I heard as well; seems people who used the systems were pretty thrilled with them. One of the doctors working on the kids and teens trial noted that he was not a fan of Enlite sensors in general but the accuracy of the sensor was sort of irrelevant because the end result was keeping children in range 70 to 80 percent of the time, with reduced risk of hypos. People only care about sensor accuracy to the extent that it prevents hypos and hyperglycemia. If someone told me they could design a system that told me random numbers – meaningless junk, essentially – but somehow kept my son in range 80 percent of the time, I’d take it in a heartbeat.
Here to respond to @Terry4’s mention from another discussion about the same topic.
Hi! @rgcainmd and you mentioned that you fear the suspend would not be accurate and drive BG crazy, and that I am off of the earlier version of this model (the 640G) bc of non-satisfaction. This is true.
But i wanna state here, that Medtronic’s Algorithm has never been the problem for me. Auto suspend worked very well, if the sensor was working. Because the pump relies so heavily on the sensor for its decisions, it wants to make sure the sensor works accurately. I had great problems with maintaining that, as soon as a calibration was a bit off, the pump screamed for a new sensor. This was just unbearable for me at the time so i went on a break.
the algorithm itself I found to be very accurate and well working.
Let’s hope this is the same for the 670G, and if the new sensor really is better working, this is very promising to me.
yep thats why I’m probably going to do a clinical trial of the new ultra fast acting novolog in my area. Until we get better insulin you wont do much better with a pump or anything else. Thats the limiting factor.
And I think you’re a little harsh on the Minimed pumps… have you tried one? I am using my old 511 and I love it. I have thought of the new 670g but it honestly looks bigger and kinda ugly compared to the one i have now lol. And from looking at the time in range, I have done better by myself using my cgm but I guess with more effort on my part. It’s a step in the right direction though!
It sounds like you’re only looking at things from your point of view and are assuming everyone is able to get their a1c down to 4.7 like you. Sounds like it’s no advantage for you but there are a lot of people who it would be an advantage for, including kids.
I agree that the time in range is not that great but I think they made it very safety conscious on the correction factor for the first launch and will get it tighter with future releases. They have to be that way I believe to get FDA approval and once that door is open they hopefully will become more aggressive in the future. If we could self program how tight we want it to make our control then that would be even better but I understand why they have to be so safe and cautious as most people are not like everyone on this board.
exactly!!!
Just an example of a kid I had in Dcamp this past summer, he didn’t even have the 670G but the 640G (which only suspends before and during lows and resumes after) and his sugars were so difficult to manage. I remember the doctor getting up several times a night, correcting, monitoring, etc. Knowig that the algorithm of the 640G was in the background made a huge difference to us and helped at least a bit. This pump can give a lot of autonomy back to kids and more sleep to parents.
If this thing only helps 1 person out there, it is a good thing!!!
Not so! No I haven’t used a Medtronic pump–but I did have a number of Nokia phones! I had them even after they were cool. You could use them for hammers!
Joking aside my problem isn’t with their pumps themselves as it is with their business model. When your MO as a medical device mfg is to negotiate with insurers that you will give them X price only if they refuse to negotiate whatsoever with all of your competitors… It’s problematic, it causes a near monopoly and it puts a stranglehold on innovation-- and ultimately the people with diabetes lose.
That said-- Medtronic (as a company) does a lot of things really well. They have a small army of reps who communicate constantly with every physicians office in the country. I’d be willing to bet that most family practice doctors in the county have spent one-on-one time with a Medtronic rep and have been shown in person how to adjust the pump settings, etc… They’re light years ahead of the rest in terms of their network.
Sensor technology is definitely the limiting factor in these systems. That said, both the Medtronic and Dexcom sensors are examples of first generation technology (Gox - H2O2 sensors), and while they are good at reading low glucose levels and are therefore able to run suspend algorithms with good sensitivity, in order to read high glucose levels accurately you will need a sensor that uses Generation 2 or 3 technology and eliminates the need for oxygen in the reaction which allows for a linear response through the entire physiologic range. So for this technology to mature, sensors need to improve, as well as the medications the pumps deliver. This is a nice baby step forward however, since making huge leaps is difficult for the FDA to swallow.
Chris72, sounds like you really know your stuff about how Dex sensors, etc. work. I would love to understand a little more! What’s all this about oxygen levels?
Looks like there is some confusion in the comments above: 670G is the first commercially available hybrid AP, a system capable of continuously adjusting basal rates based on CGM readings. Not a baby step. The user must bolus for meals manually, which is why the system is referred to as “hybrid”. This is similar to DIY AP systems (OpenAPS, Loop) I’ve been using for 9 months now, with excellent results. My understanding is that 670G trials have been very successful, with A1c dropping by 0.5-1% on average, and with users reporting substantial improvements in quality of life. I am not particularly enthusiastic by Med or 670G, but I am really pleased by the early FDA approval, and the fact that even more exciting AP systems will be coming out soon. For people with T1D in the real world (outside of DOC bubbles), this is a big deal.
I have use the Medtronic 670g for the past year and clinical trials. This pump works and is life-changing. This pump will help many people. lowes and highs are very well controlled. It is nice to wake up in the mornings and be with a normal blood sugar.
Sure, I can get as technical as you would like, but I will try and not get too far into the weeds. Generation 1 glucose sensor technology works by measuring hydrogen peroxide on a sensor. To do this you poise a sensor at a potential that reduces hydrogen peroxide (unfortunately it also reduces uric acid, ascorbic acid, and acetaminophen which all add to the uncertainty in a measurement). In a glucose sensor like Dexcom and Medtronic the hydrogen peroxide comes from a glucose oxidase reaction. The glucose oxidase enzyme has been designed by nature to find glucose and perform a reaction. Once this reaction occurs, oxygen is used to reduce the enzyme and make it active again. One of the byproducts of this reaction is hydrogen peroxide (which is what the sensor measures). The problem with this is at high glucose levels there isn’t enough oxygen near the electrode to react with the enzymes efficiently. That is one reason why you see uncertainty at the higher glucose measurements. The differences between the Medtronic and Dexcom sensors is likely due to the fact that Dexcom uses a better coating system on their sensor, since in both cases you need to limit the amount of glucose that can flow to a small electrode otherwise the system wouldn’t work.
Part of me wants to run out and get this as soon as I can (even though for some completly made up and not supported reason, I’ve always been wary of Medtronic), but like someone mentioned, it’s scary to do that and then be stuck for 4 or 5 years (it was always 4 previously, but now I’m hearing insurance won’t cover new pumps for 5 years?)
I made the mistake of choosing the newest-fangled pump last time I was due, and really feel it wasn’t ready for prime time. Having to use a tool that doesn’t work for my needs so well makes it way harder for me to be motivated to take the best care of myself…
yes, i think that’s smart. We’re lucky; our policy covers a new pump every year, but we likely won’t get this one either as we have an openAPS system and will wait till something that can bolus for meals and allows us to set as aggressive or conservative a target as we like.
The four-year thing is really a huge hassle. I think someone needs to get on an open-source version of a closed loop pump that doesn’t rely on existing pumps.
@Tia_G I do agree with you on this and I think you may have touched on my main issue with this new release here. To be clear, I’m happy to see any progress being made in the diabetes field. It’s just that my Facebook feed has been flooded with sponsored posts about this device since the announcement and it makes me seriously uncomfortable to know there’s so much money being spent here. Doctors tend to push this very expensive technology, insulin, and other medications and yet no doctor has ever mentioned to me a simple change in diet. I guess that’s what you get when there’s no money to be made…
I am not a Medtronic fan. However, for me, this is a big deal because the FDA approved it so quickly. Several other artificial pancreases are in the pipeline (Bigfoot, Damiano’s), and I believe those are probably technologically superior (and they use the Dexcom CGM, which is definitely technologically superior to Medtronic). I am hopeful that Bigfoot and Damiano’s will also get quick FDA approval once they file. Such excellent news!
Yeah I feel the same way about there business model. I hate companies that do proprietary stuff. As a private company, they are here to make money though. Researchers are the ones looking for a cure, not private companies, they are in the business to make money. I don’t understand people who think they’re bad for making money and not finding a cure. As a consumer if I don’t like the product I wont buy it. They are driving competition and that only leads to more choices so that’s a good thing.
I really like the pump itself though, or did, haven’t tried a newer one, but my 511 is very small and does everything very well.
I stopped using my Medtronic pump and CGM because it would decide not to give me insulin but never alarmed and because I couldn’t trust the CGM to be accurate. Currently using a combination of insulin pens and Dexcom and I am much happier. So would I use a Medtronic pump that would shut off insulin because of what the CGM believes is my glucose level?
Until we get better insulin you wont do much better with a pump or anything else. Thats the limiting factor.