My Miracle Box

This was originally posted to my blog, Diabetes Odyssey.

On February 13th I started full auto mode with my Medtronic Minimed 670g insulin pump. Today, March 7th, I had my first endo appointment since being on full auto mode. How has auto mode been working for me so far? I’ll let my endo’s response to my insulin usage and BG charts tell you that answer.

“Oh, my god!” Then she looked at me, “Sorry, they just look so good! Do you see how straight that line is?! Wow!”

My A1c as of February 13th was 8.5%. My endo calculates that if my current BGs stay the way they are with my new pump then my A1c when I check it again in June will be around 6.6%!

I have never had an A1c under 7.4% that I can remember.

The 670g is an insulin pump that is commonly called the ‘artificial pancreas’ which is kind of a misnomer but since I’ve been using it I can certainly see and understand how it differs and is much improved from your common insulin pump. I am not writing this blog post to go into details about the machine’s algorithm and functions, though, I’m writing this to let you know how well it’s been helping me, and mostly, how much I like it…and a bit of the very few things that have annoyed me a bit. 670

Before going on the 670g I was using the Animas Vibe insulin pump. I really enjoyed it, and especially loved pumping more than MDI (multiple daily injections).

With your standard insulin pump you program in your ISF (insulin sensitivity factor) as well as your insulin to carb ratio. You can also customize times of day to be administered different basal insulin amounts and different insulin to carb ratios.

The way the 670g differs and is improved here is that it automatically determines, based on your CGM readings and BG #s entered, what your basal needs are in real time and adjusts as needed…on it’s own.

All you need enter is your carb counts whenever you eat carbs.

So, as a result, your BG evens out and stays even and well within your ideal range.

I can certainly understand if you are worried about “What if the CGM is inaccurate?” That was my biggest worry. Through calibrations and regular self checks both you and the machine make darn sure the CGM is accurate.

Believe me, there are a million safety features built into this little wonderful device.

I have had zero low BGs since I’ve been using it, and very few highs. And the highs I have had are still much lower than the many highs I was having before I started using the 670g.

The system can kick you out of auto mode sometimes. There are several reasons you will get kicked from auto mode, like if your CGM is not working or active, or if the system determines your BG is too high or too low for too long. You may get kicked out, but it will put you back into auto mode automatically as soon as the issue that got you kicked is resolved. This is yet another safety feature. And don’t worry, if you get kicked out of auto mode it puts you right into your presets for manual mode (which is just like how your standard pump works) so you will still be getting insulin, etc.

I have spent 90% of my time since starting auto mode in auto mode. I was very happy to hear this.

Before starting the 670g I was using a lot of insulin, about 75-100 units per day, and still having horrible trouble keeping my BG down. Since being in auto mode I have been using an average of 63 units of insulin per day, and my BGs are mostly well within the ideal range 80-120. What is it they say ‘Less is more when you’re doing it right’?

Alas, I tell you all this joy and wonderfulness about the 670g and auto mode. But, as with everything in life, there are some headaches. But, as you’ll find out, these headaches aren’t that bad, and even with them the 670g is so very worth it.

The 670g system uses Guardian CGM sensors. These are wonderful. I could sit here and compare them to the Dexcom and explain why I love them more than Dexcom, but I won’t because that’s not what this post is about (and I don’t want to badmouth Dexcom because I do like them, too). The only complaint I have with Guardian sensors is that 3 out of 5 of them so far have failed on the beginning of the 6th day when they are supposed to last a full 7 days. They worked wonderfully, great accuracy and zero problems up until the 6th day, then they go into “Sensor updating” mode for several hours and then inevitably I get the “sensor failed, change sensor” message. I don’t know why this has happened with 3 out of the first five sensors I used, but it is annoying.

Alarms…ugh! Alarms. Especially head-achy when they happen in the middle of the night. If you are a pumper and/or CGMer then you are already well aware of alarms. The good thing is that they are there because they help keep us alive and in line. But, jeez, they are annoying. The alarms I find going off the most often for me since I’ve been using the 670g is the calibrate alarm, usually only twice a day (every 12 hours) but sometimes other times as well. Also the “enter BG” alarm. This is different from the calibrate alarm, entering BG means the system needs you to check your BG and enter it into the pump for safety (system self check) reasons. If you don’t check and enter your BG then you will eventually get kicked out of auto mode until you do. Then, of course, there are the ‘change reservoir’ and ‘change sensor’ alarms that happen regularly, every 3 days and once a week respectively.

All-in-all I am super happy and loving the 670g more than any of the many, many tools I’ve ever used for my diabetes. It has helped me get and keep my BGs in line more than anything I’ve ever used/done. Of course this is only a tool among many, but, jeez, I could call it magical it’s helped so very, very much.


I am so thrilled for you! It is so cool to hear that the technology works. I have seen quite a few people’s CGM tracings and they are beautiful! The technology can be a lot of work but once you get a handle on it it can make your life so much easier.
And a side note to your discovery about the amount of insulin. I have also realized that wow, I was using way too much insulin everyday. And once I learned that less is better, things stared to come in line. I am 22 TDD instead of upwards of 35-40. And because I am taking so much less insulin, I no longer need to “feed the insulin”. My biggest issue was learning that I couldn’t just snack like I use to when my basal was to high. Now I need to think if it’s worth dosing for that snack or just forgetting about it. So less insulin, less lows, less snacking to fix lows and less extra weight due to empty calories.
I love you successes of late. You seem to be working very hard and it looks like it is paying off for you! I am hoping to get into one of the AP clinical trials sometime this year and hope the results are as great as yours!


Brava. I am delighted for you, Tamra!..Judith in Portland

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A few months ago I switched from eating everything I liked, in any amount I liked, to eating a sensible diet of mostly veggies, fruit, meats, chicken, fish. No more Pop Tarts when I get low. LOL. Result? I went from 236 lbs to 209, A1c from 6.1 to 5.7, and insulin usage per day of 51 , to around 26. (I wish MM Carelink would allow for the reports to cover more than 2 week periods when using the “Trends Summary” report type, so that I could cover numerous months’ averages) Fewer lows, fewer highs. Using a pump brings about a huge temptation to eat “anything”. Not a great idea, but one I sadly have given in to for years. In fact, about 5-6 years ago I went onto MDI to lose weight. It worked, but was too dangerous, too many lows, too difficult to control highs, too hard to deal with intermittent heavy activity.

I switched back to my pump after one year and wondered what in the heck I was thinking to have gone off of it. THIS time, I stayed on my pump, but am adhering to an intelligent diet.


I’m so happy that you’re having such success!! I’m in the process of looking at my next pump, and it’s stories like yours that make the Medtronic ever so tempting (though we only have the 630G here in Canada). But I pay for my Dexcom entirely out of pocket, so reports that the MEdtronic sensors just can’t be “stretched” as long is really a deal-breaker for me. I will probably end up with Tandem and will hope that they come out with their AP system in the next couple of years (and that it’s a free or reasonably-priced upgrade).

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This is wonderful news, Tamra! I’m always happy to read about diabetes success stories. I look forward to reading more about your 670g experience. Keep up the good work!