670G and Me

670G and Me: Insights and Incites on Medtronic’s Latest System by Gary ScheinerGary Scheiner (Integrated Diabetes Services)

Trust me, passengers on this cruise ship don’t get to lie around on lounge chairs and be waited on hand & foot. This is a working cruise! Expect to spend a fair amount of time in the kitchens and engine rooms. You’ll need to manage/maintain both the glucose sensor and the pump. Plan to perform fingersticks four to eight times a day for sensor calibrations and to keep the auto-mode feature running smoothly. Expect more alarms and alerts than usual. You’ll need to plan well-ahead to prevent lows (and highs, on occasion) when exercising. And you’ll still need to manage things the old-fashioned way when out of auto-mode (typically 10-20% of the time), and that means making sure your basal and bolus settings are properly fine-tuned.

It also takes a shrewd captain to navigate this ship. Using the 670G and its full array of automated delivery features requires a great deal of training, aptitude, and attention to detail. Compared to traditional pump therapy (with or without an independent continuous glucose monitor), 670G can be quite complex. Training typically requires three separate sessions: one to learn the pump, one to learn the sensor, and one to learn the automated basal delivery system (auto-mode). One must understand all of the conditions that are necessary for auto-mode to activate. There is even an “auto-mode readiness” status screen that is nine items long! You’ll need to know when/why the system may go out of auto-mode, and how to get back in. And then there’s “safe mode” – a sort of purgatory between auto-mode and manual mode in which the pump is delivering basal insulin but not self-adjusting it until an auto-mode problem is fixed. I’m still trying to wrap my brain around that one.

People who maintain a structured and predictable lifestyle also tend to succeed with 670G. There is much less chance of a cruise ship mishap in the Caribbean than in the Arctic Circle because of the lack of icebergs. Someone whose life includes frequent/inconsistent meals & snacks, random physical activity, changing work shifts, varied sleep schedules or significant stress is going to struggle in auto-mode. By contrast, those who eat consistent/well-spaced meals (with minimal snacks), work out regularly (or not at all) and lead generally relaxed and predictable lives tend to stay in-range most of the time in auto-mode. And for that matter, those whose basal requirements include a significant peak & valley (based on previous pump use & basal fine-tuning) may struggle a bit due to the limited basal variations that can take place in auto-mode. Those with relatively stable basal requirements throughout the day & night are more likely to experience success in auto-mode.

Argh! The frustrations are so bothersome that I often have fantasies where I smash my 670G to bits with a hammer. And then I burn the pieces.

Week 3 with an insulin pump

Tomorrow will mark my third week with an insulin pump. I had originally meant to blog my daily or weekly experience with the Accu-Chek Combo but I just did not have the time. I had too many work and home life activities.

My first week was the best. Even though I had a lot of hypo episodes I felt more free. My first weekend with the pump I was able to eat pizza; something I have not done in a while. Eating pizza was like giving my blood glucose a ride at Great Adventure1. With the mutli-wave bolus feature of the Combo I could eat pizza and not worry too much.

My second week was hell. At least that's how I would characterize it. As I worked with my certified diabetes educator (CDE) to adjust my basal rates, I experienced multiple daily hypoglycemic episodes. Some occurred during the day and some at night. Thank goodness for the Dexcom G4! We adjusted my basal rates and bolus ratios so many times that I have no idea what my insulin/carb ration is. It was just all too overwhelming.

This week I am taking it a bit more in stride, although I did start off the week in a bit of a huff. I wanted to get some useful data for the CDE so I decided that on Monday I would eat the same thing for all my meals that day. I had Trader Joe's Steel Cut Oatmeal for breakfast, lunch and dinner.

My BG pattern for the day resembled the ride pattern for Kingda Ka. It went straight up and almost straight down. I was hypoglycemic -- in the 60s -- most of the day. I refused to treat the hypo. I wanted the CDE to see the pattern and sucking down glucose would have meant throwing out the results. The CDE yelled at me when I should her my data later that night but she admitted that the data was useful. My basal rate was too high. We made some adjustments.

Yesterday I went back to eating my normal breakfast, lunch and dinner but my numbers were not much better. I still got a post-prandial hypo after breakfast and lunch but dinner held steady. I went to bed with a BG near my target of 100 and woke up this morning with a BG near target.

This morning I adjusted my breakfast regimen. I took my bolus and waited 20 minutes before eating. My BG did not rise as quickly and dropped into the 80s before lunch.

I don't know how to interpret all this data. I'm hoping the CDE does. Trying to find patterns and trends with so many variables is a daunting task. Unfortunately, I'm a Mac and most diabetes medical devices are Windows. I have no way to download and chart my data. That's a real issue for me. I think if I could look at the data from my CGMS combined with my meal and insulin delivery data, I could find some patterns to inform my diabetes management.

Next Saturday I am scheduled for an early morning fasting blood glucose test. I will use that opportunity to fast until noon. Hopefully we can get an idea of what my BG does in the morning. I don't want to do this more than once. The CDE wants me to do another one for lunch but that will have to wait for another weekend. Fasting during a busy work day would leave me miserable and exhausted.

One thing I am still trying to figure out is where to place my pump. My biggest challenge is going to the bathroom. Placing the pump on my belt loop works only so long as my pants don't drop around my ankles. I've had a some situations where the pump tubing was very taught.

I've received several suggestions via the forums on tudiabetes.org and elsewhere. None of them seem practical for me. One suggestion is to strap the pump to my lower leg or my waist or chest neatly hidden under my clothing. I think this would be uncomfortable and the strap would become and irritant. One of my client's offices has security scanners. At least one a week I am at that site, placing my computer bag on a conveyor belt for scanning, removing metal objects from my pockets, and of course setting of the scanner alarm with my insulin pump. It's a lot easier to deal with when the pump is visible. I also don't see how strapping my pump around my chest and under my clothes does not leave a visible bump under business clothing. I'm usually wearing an undershirt, a long sleeve dress shirt, wool pants and if it's Winter, a sweater. I dress like this guy, except I'm not as handsome and don't wear a tie.

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I'm looking forward to Week 4. According to some of the people on the forums on TuDiabetes.org it can take up to 6 weeks to fine tune my insulin pump. As long as I see progress, I won't be as frustrated.


  1. Great Adventure is officially Six Flags Great Adventure