Issues with the 670G “Looping”


(davyboy) #81

do you by chance use acetylmetaphines for pain? It renders the very accurate Dexcom 5g inaccurate.


(Kathy) #82

Hi @kmoon Kyra. I hope things are working better for you. I struggled a lot right from the get-go. I took me 8 months to finally figure out what works for me. I don’t know if any of these will help you but they are something to consider:

  1. make sure you are well hydrated. It is a really big deal and being even slightly dehydrated can mess up the sensor readings
  2. Try other sites. I only use my thighs and arms. My abs just don’t work for me. In addition I get really lousy sensor life (about 3 - 4 days) on the abs. On a side note - the G3 sensor is now officially approved for the arms.
  3. Make sure the sensor and transmitter are taped really well. The sensor/transmitter duo moving can cause problems with the sensor readings
  4. Only calibrate if your SG and BG is in the proper range. There are 2 ways to check this. The first is the BG is +/- 35% of the SG. The other is to divide the BG by the ISIG and if you are between 3 and 8.33 you are okay to calibrate.
  5. try marinating the sensor. I have had really good luck with this and am finally starting to trust AM. If I need to change a sensor in the morning, I’ll insert a sensor before bed the night before. I leave the transmitter on the old one and let it and auto mode do its thing. In the morning I charge transmitter and start the new sensor. Warm-up is sometimes a little shorter (maybe 90 minutes) but the big thing is the SG is within +/- 10-15 points and I generally get a 6 hour calibration on the first calibration and I can trust the SG readings rather than fighting with them for the first 24 or so hours (I get a lot of completely incorrect really low SG readings which can really mess up the auto mode algorithm if I don’t marinate). A lot of people who are struggling with the erratic first day sensor readings have had good luck with this one.

I expect you know this stuff, but it might help others.

Good liuck. Stay strong.


(davyboy) #83

Geez, you guys have to go thru all that??? I am just going to get a T:slimx2 and my Dexcom g5 and wait till the Tandem closed loop software is approved, then they will download it into my pump. The Dexcom is so accurate, it even adjusts well when my glucose is fast rising or fast falling, except the one time when initially calibrating it.


(Kathy) #84

Hi @davyboy. No not everyone goes through this. Most have absolutely no problems with the Guardian 3 sensors but there is a subpopulation of 670g users that struggle with the sensors. I happen to be one of them. I expect that there are people who struggle with the Dexcom sensors too. Its just a matter of how the sensors work with your body.

I am happy for you that you have a solution that works well for you. I wish you well.


(Jack) #85

@davyboy … I was a t:slim pumper before going to the 670as per the request of my Doc. I have one, and I do mean one, good thing to say about the 670. My A1C is better than it’s ever been. Past that, it is a piece of crap pump. From the antiquated technology to it’s constantly kicking you out of auto mode and everything in between. If not in auto mode it is just another pump. A piss poor pump at that. I miss my t:slim so bad that I am prepared to fork out what ever the cost to get back into their new slimx2. The night shift is the worse with the 670. can’t tell you how many times I’ve been asked to go to the couch as I cycle through the menus after an alarm in the middle of the night. I’m sure most think it is a little click as you hit the buttons to advance through. For my wife, at 2:00am, its not just a click. It’s CLICK CLICK CLICK CLICK CICK!!! (Can you go out on the couch, dear) My advice to anyone looking at the 670. . . RUN! tandem does an amazing job of designing their pumps around the patient. Seeking out our advice while in development of something new. I was told by my Doc that Tandem was going out of business because of the 670. I checked the stock market on them that very day, Sure enough they had tanked big time. under $2 a share tanked. Man do I wish I had bought 5 grand of that stock back then. It was at 47 back in September. I’d say they’re gonna be around a while.

Stay with Tandem, davyboy!


(Janet) #86

I have been type 1 for 50 years now. I got the 670G a year ago. I too have been having the looping issue. I am averaging 10-11 strips a day. I like the sensor and auto mode but the looping and time it takes to warm-up and calibrate is frustrating. Thanks for everyone’s suggestions. Today I have tested 8 times since 8 am and it is still requesting a blood sugar reading.


(Kathy) #87

@janetschu Hi Janet. The looping issue is well known. Your best bet is to give Medtronic a call and report that you have the looping issue. There is a newly approved transmitter that does fix this issue. If you report it and are still under warranty, Medtronic will replace it when they are available. If the transmitter is out of warranty with the a new transmitter will need to be purchased. Medtronic can also provide guidance on how to get out of the loop.

There is a facebook group “Medtronic 670G Support Group” that has a lot of information and techniques to deal with it.

The basics are: calibrate. If the pump asked for a BG you can send it over. If it asked for a second one, ignore it for at least an hour. There is varying guidance on how long to wait (I believe Medtronic is using 6 hours but others do okay with shorter waits). I use 2 hours. You can then give it a BG if it still wants one. If it asks for a second BG, ignore it and wait again. If it does it again the 3rd time, call Medtronic. You may have a faulty sensor or transmitter.


(Jade) #88

I am so glad other people have the same expiriences as I do. I feel like I have had quite a few problems with the 670G and have eventually switched back to my Dexcom. My problems range all the way from looping to sensor pain. However I did find looping facebook groups and groups through instagram very helpful! Good luck1


(Kathleen) #89

I understand completely! Having had a previous Metronic pump for 7 years, I had maybe two sensor failures. In the last 7 weeks with the 670G, I have gotten caught in the same BG loop, then sensor failure. Each time, I called Metronic and spoke with an educator. I was sent a new sensor which was fine, but the frustration was there every time I inserted a new sensor. I still don’t understand why.


(Janet) #90

I changed my sensor yesterday and did something different. I took it off auto mode and let it warm-up and do calibration before switching to auto mode and that seemed to work.


(davyboy) #91

I once tried to make Medtronic improve their reservoirs so they wouldn’t pick up air for the 3 days it is in use (Many ppl reported air bubbles magically appearing in their insulin in the reservoir, which at some point will go up the tubing and into your skin, and the pump logs it as insulin. Turns out FDA had two complaints about this and still didn’t make Medtronic solve the problem. Medtronic had told me the reservoirs met the design standard, and they say the same thing to the FDA, which had given the okay to Medtronic to sell the device to the public. I said the design IS the problem.

The whole process of research, design, testing and revision should shake out any defects in the design, before going into production. Protocols should be tested on real diabetics for at least a year. I know that they did exactly this, yet still released the sensors with problems in them. I also read on Type One Nation about problems in the pump itself–in the software algorithms. This makes little sense to users, who shell out 7000 or 10,000 dollars and high costs of supplies.

There are controls engineers in all high tech industries who design systems to perfectly match what is happening in a real life system. A diabetic’s glucose level involves real life systems. The software algorithm is supposed to be self-improving in the sense that it gets more and more accurate with time in use on a particular system…Great success in numerous industries with digital controls has yielded a special field of engineering, of control systems. These people often have their own businesses that help develop such solutions that should have been done for the Medtronic 670g. It’s true that the human body is particularly complex with many variables. But digital control systems are supposed to work in such an environment.

So i don’t understand why Medtronic sets the control point to 120 glucose level instead of 100, so it won’t dip down into hypoglycemia. Why does it go into a wild, out of control loop? Why didn’t Medtronic design the pump to be software updatable, like the Tandem T:slim X2 pump is? Usually that is because they plan in designed obsolescence with profits as the goal. But poor quality equipment foisted on diabetics? That is unacceptable and I hope you complain vociferously to your doctors and to the FDA. It has an online system you can use to report your complaint. If they get enough complaints, they will act on them. There is a close relationship between FDA and the medical industry, so you have to be aggressive to get action. Don’t let them accept the lawyer-written answers to your complaints.


(Kathleen) #92

I was told up front by my educator that the first month would be horrible. She was right. When it worked, it worked well, giving me peace of mind. When it got caught in the BG loop, it drove me nuts. Metronic has replaced each one that malfunctioned. It’s easy. Today they are sending me a new transponder since I had so many errors. Praying this one is better. My Endo asked me to give it time. The pump / sensor has to get to know me and vice versa. Far less problems now. Looking forward to a better A1C!


(Kathleen) #93

This is exactly what Metronic just told me on Monday. So you wait for an hour and try again. I went through many of sensors because of a BG loop.


(Leslie) #94

Work arounds are necessary with this pump. Hardware is great. Software and support are bad jokes. I’ve had pretty good luck on solving looping by turning off auto mode and immediately turning it on. Then putting in bg directly from screen from screen. Trying testing and using from meter didn’t work.

Also I never put a real bg in when there are arrows use the reading on pump. For every event pump asks for a bg. Why we would calibrate during an event I cannot fathom. I calibrate and strart sensor only when stable as a rock. Otherwise you end up having a pointless conversation with a rep for a sensor replacement. Sensor needs two calibrations day not 5 in 30 min.
I particularly love working through screens of advice when I want to find out sensor reading.
Minimed is spectacularly deaf to complaints about these annoyances.
It can work but you need to lie to it to get your insulin. Auto mode will correct minor variations but you’ll need more insulin if your 50 pts high.


(T1D) #95

Yes, do this! Somewhere in the labyrinthine Medtronic website, there is an online form where you can report your transmitter’s serial number and request a new one – but the form states (and my trainer verifies) that it will take 90 to 120 days to receive it.

Instead, call 1-800-646-4633, follow prompts to technical support, and explain that you have the “Repeated Requests” issue. I called yesterday and a new transmitter was overnighted to me today!

It’s far too soon to know if it solves the problem, but I’m impressed with the speedy response. But you have to pester them personally to jump the line.