I’m sensing some trouble
Hi loyal readers (if you’re still out there)! Sorry for the lack of updates recently. Life has been crazy lately…I’ve worked more than I really care to think about, and there’s just so much going on that I’ve barely had time to comprehend it myself, much less write about it.
So anyway, I’m over a month into using the Medtronic CGM sensor. Overall, I really like it. Although the accuracy of the data isn’t yet at a point that I completely trust it, I have found the extra information is definitely helpful in controlling the blood sugars. In fact, when I’m not wearing the sensor, I feel like I’m “flying blind” without knowing which direction my sugars are headed between meals, before exercise, etc. On the whole, I haven’t had too much trouble with the sensors, but today has been a bit of a battle. I started a new sensor this afternoon, but was never able to get it off the ground. I had repeated “Lost Sensor” alarms and tried restarting the sensor several times, but never was able to get to the calibration stage. Finally I gave up and yanked the sensor out, feeling like I had just wasted $10. I started a new sensor and seemed to be off on the right foot this time, but my happy thoughts were soon dashed a few hours later. After finishing a run, I looked at the pump to find out the sensor said I was at 200 mg/dl and rising at a “double arrow” pace. I didn’t feel like I was high, so I checked with my meter and got a result of 94 mg/dl. WTF? I didn’t realize this at the time, but the sensor site was bleeding pretty heavily, so I suppose it’s possible that the fact I looked like an extra from Smokin’ Aces could have affected the accuracy of the sensor. I cleaned things off during my shower and restarted the sensor yet again, so we’ll see if things get better from here.
All of this sensor trouble has reinforced the thoughts I had after watching the news story on ABC news last week about the “artificial pancreas”. Unless I misinterpreted the graphics in the video, the components of this “closed loop” system were essentially the same sensor and insulin pump I’m using, with an additional device to bridge the communication between the two. To me, that part doesn’t seem that complicated – it’s really just a series of calculations, not unlike what the Bolus Wizard function already does. In my opinion, the biggest hurdle to such a closed loop system is the accuracy of the sensor technology. Although I’ve certainly seen some benefits from the information the sensor provides, I feel like there are still some huge improvements that need to be made before we can rely on this technology for dosing decisions.
While the thought of an artificial pancreas is enticing at first listen, it’s still not a cure. No matter how much we’re able to make the different technologies communicate with each other, there will always be a human component as long as there are electronic devices to be managed. There will always be sensors and sites to change, calibrations to be made, and batteries to be changed. Truth be told, this just seems like a band-aid (albeit a technologically advanced one) to deal with the disease, not a solution to the problem.
Ahh, feels a little better to get that off my chest. Hopefully I’ll have something more for you again soon, and if you’re lucky, maybe it will be a little less Debbie Downer.
25 Units To Go 
It is exciting – there’s a video on JDRF’s site with a young woman saying the three days she spent in the hospital with an artificial pancreas is the best vacation she ever had. That says a lot. But you are right, it still is not a cure. I understand your point re: band-aid.
The APP has been tested with various pumps and sensors and I think the biggest hurdle (although you raise a great point with the sensor accuracy) is the algorithm that drives all the dosing decisions – it’s complex.
Thanks for the post. Not a downer at all.
For the Artificial Pancreas project, I think they’ve been using different CGM devices. Right now they seem to be polishing the algorithms. When it’s eventually here I think I may wait until the 2nd version before trying it out.
Does Medtronic provide a replacement sensor when you have the problems you described? I had a failed sensor last week after 3 days and Dexcom replaced it for me. This has happened maybe 4 times in about 28 months with a Dexcom.
I agree 100%!! I love my CGM and feel lost without it. (I have the Minimed one too) But I am in no way comfortable with the thought of my pump automatically adjusting my insulin based on info from the CGM – at least not yet. There is too large of a margin of error there.
And yes, it would NOT be a cure. I would imagine we’d still need to watch our carb counts and what we eat. I can’t imagine the closed loop system could keep us stable if we ate a ton of French fries followed by a hot fudge sundae, could it? **Not that anyone should really eat like that – but I’m just trying to make a point. 🙂 **
How would the artificial pump adjust for a low, I can see it feeding me insulin to cover my carbs but what happens when I am going low, reducing the insulin would not be quick enough. I am a bit confused, but I am still hopeful.
Oooo and by the way I used the MM CGM for a bit, but I was not a fan. The lag time drove me nuts and I over treated lows quite often. If I did not eat or move and the CGM flatlined, it was wonderful, ha, but to see highs for hours on ends when you got into that mode was TMI constantly staring me in the face.