670G or wait for 780g (currently on TSlimX2)

I live in Houston. I totally understand the humidity thing with adhesives. All of that information clarifies the differences between the auto and manual modes. Thank you. The reason I want the 670g is because of the closed loop. If I have to go into manual mode at night because of alarms then that might defeat my purpose. I get enough alarms now with my Dexcom at night. Although overall I LOVE my Dexcom. Thank you again. I will address all of this with the rep. Next week.

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You can silence ALL alarms except for “Sensor Glucose Over 400”, “Sensor Glucose Below 40”, “Battery Low Delivery Suspended”, and one other critical alarm I can’t remember off the top of my head. Menu > Audio Options > Alert Silence Options > All Sensor Alerts, you can then select 0:30hr to 24 hrs duration in 30 minute increments. If Automode runs into trouble, it will first go into a reduced basal “Safe Auto”, eventually it will exit to Manual Mode. If your glucose reading ever drops below 40 in any mode, basal delivery is stopped until you come back above 40, this is a safety feature you cannot disable. I think you have to manually enable “Suspend on Low” and “Suspend Before Low” for manual mode every time you exit Automode into Manual Mode though, because these features are ‘turned off’ in Automode. You can select a conservative basal rate in manual mode before going into Auto Mode, that way if you drop out of Auto while you’re asleep you know it won’t drop you low. Manual mode basal patterns do not effect Automode rates in any way.

To be successful in Auto Mode(closed loop), it is imperative that you get your insulin sensitivity factor, carb ratio, and active insulin time dialed in. The amount of carbs you’re telling the pump that you are eating also needs to be fairly accurate. Automode just looks at the past 6 day rolling average of basal delivery per time of day, makes minor adjustments for glucose reading rising or falling in the last 5 minutes, and delivers the appropriate basal. It takes the safest approach to discrepancies by assuming that any error is the pump or calculuation’s fault, and starts asking for a confirmation BG reading to make sure it’s making safe decisions.

You can’t use a fake bolus to correct, that trips up the system; you must give “Bolus Wizard” a BG value and let it handle the correction bolus. If you have a low BG and eat something to raise it, you have to enter that BG and Carb count into the “Bolus Wizard” screen; bolus wizard will know to not give a certain amount of insulin in order to get you back up to target glucose reading, and Automode wont get tripped up wondering how your glucose came back up.
Any small snack needs to be entered into the pump or it wont know that you ate and will assume a basal delivery error.
My sensor readings have always been more accurate than my glucose monitor, so at this point I feel safe entering an SG reading into BG field for boluses, but you shouldn’t ever calibrate your SG off of a SG reading.

In summary-
If you are willing to give total control to Automode, and you can accurately give it carb counts, then it will work great for you with minimal alarms going off.

I maybe read a fourth of the 450 page manual, it is a daunting task. There is a lot of critical information in there though.

I got in the habit of reading user manuals a long time ago, at least for “critical stuff”.
Before actually ordering my CGM and new t-Slim I had read only the “quick start” pieces but once ordered and before delivery I had read enough to avoid problems - now I have links to the manuals handy on my computer.
The only thing I’ve used the manuals for since I got the pump and CGM is to answer questions asked of me; I even have the Medtronic manuals linked so I can quote when asked.

@RosiesAllStars - I did the same thing you did (switched from the Medtronic Paradigm Revel to the T:Slim, then after 6 months switched to the Medtronic 530g, then after 2 months switched back to the T:Slim). In my case - the first Tandem pump had a bunch of issues (lemon?) and by the time I got the replacement Tandem pump, I was at my limit. However switching back to the Medtronic (even the new one at the time - the 530g) felt like I went back to the dark ages. I missed the design, look, and feel of the Tandem pump. Have now been on Tandem for a while, LOVE it, and can’t wait for Control IQ.

In case the loud alarm every 15 minutes when suspending the Tandem still bothers you, I have a solution. That alarm annoyed the heck out of me, and a Tandem trainer gave me the idea of setting a new profile called “Suspend” with a single basal rate of 0. That allows you to “Suspend” the pump by switching to that special profile, and voila - no alarms! Only thing to watch out for is to remember to switch back to your normal profile (hmm…if only there was a loud, annoying alarm to remind me every 15 minutes).


I am using a dexcom g5 with a medtron 630. I didn’t like their sensors so I switched back to using dexcom but I lost the feature of my pump to suspend when the sensor would go below a certain threshold. I am not due for a new pump until 2021. I suggest that you wait for medtronic to communicate with dexcom g6. I have heard alot of people complain about the tslim. Do your research. Good luck.

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It is a difficult thing to decide. What have you heard the most negative about T-Slim? Most I hear is good.

After a valiant effort in Auto Mode for 10 months with my Medtronic 670, I switched to Manual Mode and am finally sleeping again. My BG numbers are better too. Auto was keeping me too high, even without eating or need for Bolus. It was constantly giving me some kind of notification, even if no issue, like Enter BG in the middle of the night, when there was no Max or Min delivery and BG was fine, like a 116. It was really tortuous and I have no regrets. I’m going to see how this works for the next few months and then decide if I will make an even greater change.

I still don’t trust the Guardian CGM for reliability. It’s accurate enough, but, will fail when you need it most. That’s an issue and I have to figure out my backup plan for wearing an additional CGM for important events like vacation, plane travel, etc. The CGM just seems too delicate or fickle to withstand operating in real life, imo.

My sentiments exactly. I was bummed when the first model t:slim didn’t meet my expectations in 2013 (pre-CGM era). After receiving the 670 last April and having issues with the sensors and maintaining Auto Mode (the alarms got to be a bit too much and I found myself putting in BG’s to shut it up in the middle of the night) - I’d had enough. Not really how I want to sleep or manage my levels getting back on the pump.

I was already a fan a Tandem, but partnering with Dexcom was what sold me.
So it was either: A). Ask my insurance to cover the x2 or B). Use Tandem’s upgrade program to receive a “loaner pump” for the duration of your current pump’s warranty.

After saving up for some time and doing some research, I chose to do the latter. I started using my Dexcom system a month ago and I am beyond pleased with the trend arrows (my fav), zero fingersticks as well as the ability to share my BG levels with my hubby. I’ll have the pump in hand on Friday and my only hope for it is to work properly.

Sorry for the rant. I enjoyed my 670g and my Endo raved about it for months. Unfortunately, it’s not working for my lifestyle at this point. Please don’t let this deter you from waiting for the 780g if you feel that the 670g’s features and options will benefit you.

Amber @ANC8495 and everyone else, you may want to read a very concise and accurate report for all AIDS [Automatic Insulin Delivery Systems] currently in the pipeline; the link below is from yesterday’s diaTribe newsletter. Keep -n mind that there probably isn’t one system that is BEST FOR ALL; the summary offers both pros and cons and lets each of us decide best-fit.

BTW, I strongly recommend regularly reading the diaTribe [diatribe.org] newsletter; subscriptions are free and I find most current, helpful and accurate reporting. I support the site as best I can.

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If medtronic doesn’t come out with the 780 pump by 2021 I will have no choice but the tslim because I love the dexcom cgm. That would be my main reason for going with the tslim. Just as long as the pump I do choose is self adjusting. I am fed up with having to do the extra work to keep my bloodsugars in range.

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The Medtronic 780 is slated for a mid 2020 release. There has been NO confirmation from Medtronic that they will partner with Dexcom other than they are open to the idea in the future. This was part of a conversation in which they were discussing working with Tidepool to develop an algorithm for their pump system.

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@Jason1, do you know how the 780 is supposed to be better? I just spent Saturday evening starting a new sensor at 6:00 p.m. (I plan to do it in the morning, due to issues and time commitment.), but, it just quit and told me to change sensor 2 days too early. Great. Then, the next day, CGM jumped into Start Sensor or Restart Sensor out of the blue, (it had been working for 24 hrs) so, I had to start another warm-up period for a SECOND day in row. THEN, it gives me a Low battery warning at 4:40 a.m. I get up and put in new battery that is fresh from package, that it won’t accept. Had to try a couple to get it to accept it. So, It’s really something that I cannot see me doing much longer. And, this is just a little of what I’ve experienced. It’s very stressful.

Dee, I don’t know that much about the 780. I Googled it and read a few articles about it. It seems Medtronic have addressed the issues that were driving people crazy with 670. Apparently, auto mode will be much easier to remain in, the pump will also have a user selectable BG target that will go as low 100 instead of the mandatory 130 on the 670. This is all I can remember about it now. I believe they’re hoping to launch the pump in April.

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I think the weak point for the 780 G will be it’s continuing reliance on the Guardian sensors, and their supposedly 2 to 4 finger sticks/day. i am on the 670 and on days that I am active I am often asked by the pump to do multiple more… somehow I don’t think they’ll ever hook up with dexcom. Currently my insurance doesn’t cover the dexcom sensors yet otherwise I would proably switch to the tslim and the dexcom…

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@MikeW Mike, I’ve heard that Medtronic is submitting request to the FDA for “non-adjunctive use” of the Guardian sensor; if approved, that would mean that the annoying “calibration needed” messaging could be removed from the Medtronic software. Currently, the Dexcom G6 is the only sensor with the “non-adjunctive” use designation.

Have you asked your insurance carrier to cover Tandem and Dexcom for you? My insurance carrier has an “exclusive” agreement with Medtronic, but I plead my case first through Dexcom and six months later through the Tandem representative and I was “awarded” full coverage for Dexcom July 2018 and Tandem January 2019 - I really like these devices.

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@Jason1, it sounds nice to be able to stay in Auto mode with a 100, but, there is so much more that is problematic for me. IMO, many of the issues are just plain common sense. I can’t help but wonder why their trials didn’t expose these holes. Like so many notifications for basically nothing. They don’t appreciate the problem of sensory overload on a person who is managing Type I. Just following a Type I for 24 hours would shed a lot. I wonder if they did that.

One thing that would be an improvement to me, is if the screen on the pump were to be reversed, so that when you need to read it, you just tilt it a little and it can stay in place for you to read it, rather than having to remove it from your waist band and turn it around first. Just odd, imo. In the current position, it benefits no one, unless another person needs to read your pump screen and their head is at your waist level. lol

I would like a notification that NEW sensor will be needed within 8 hours. That would prevent me from forgetting to do it that morning and instead remembering to do it in the evening, which is not good. But, instead, I get multiple worthless ones. lol

So, I will remain optimistic about the improved version. Will I get the choice of this upgrade free?

Ref. Dexcom CGM. I used to use Dexcom 5 and my insurance (BCBSNC) covered it fine. I just have to get all my supplies through Edgepark, which is no problem.

@Jayne, I’m intrigued by your post. So, you are using 670G without CGM, just in manual mode? I didn’t know that was a real option. Doesn’t it keep telling you to change sensor? I’m just curious as to how that would work.

Hi Dennis

Thank you for the info. I finally caved in to the requests by doctor to get a sensor in October 2018. At that point I was told that the G4 was covered but not
the G5 or G6 so I went whole hog and got both the Medtronic sensor and pump. I’ve been experimenting and playing with both for the last year while reading a lot of your posts and planning my strategy regarding this. I have heard through a contact in the
pharmaceutical industry that the dexcom G6 is going to become covered by my insurance sometime during the first quarter of 2020. At this point I am thinking of contacting Dexcom monthly starting January to see when and if it becomes covered. If I don’t
get any results by the end of March I will probably attempt using the strategy you suggest.


Yes I’m in manual mode.
I turned off my sensor.

In the menu scroll to:

Utilities > Sensor Settings

Jodi Johnson

Sent on a mobile device

Yes I’m in manual mode

I turned off my Sensor

Utilities >Sensor Settings

Sensor OFF

I am much happier and my A1C is too.

This is my personal experience.

Jodi Johnson

Sent on a mobile device

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