Here is maybe a bit stupid question - most of us are indeed not happy with the idea of fixed target value of 120 mgdl or 6.7 mmoll. Now, theoretically, would it not be possible to input “adjusted” calibration readings in order to fool the CGM and thereby achieve a lower target?
Here is an idea that i had. Let’s say that we want the target level to be at 90, could this be achieved by telling the pump that our blood sugar is always 30 mgdl higher than what it actually is, making it believe that we are at eg. on 150 when we are on 120, whereby it would then work on getting us down to 120, when it in practice would be moving us down to 90.
This of course depends on the idea that the calibration is the only “landmark” that the CGM and pump are using and that the chemistry in the sensor itself is not having the first lien on the decision.
Do you feel that the sensors are capable of given accurate info, all day, day in and day out, regardless of the “offset” you are considering of applying to their calibrations? I spent about a year or so using MM sensors and I wouldn’t ever go back to using them. How they made it through the FDA approval process just became clearer to me the other day, while discussing them with my endo. What they did was ignore “outlier” patients during the studies, in order to reflect better accuracy in order to gain approval. I could tell you more stories second-hand, from my wife (she is an RN), about doctors who fudge studies they are commissioned to perform. My endo even gave me the name of who was involved, but I won’t divulge that here, sorry.
Sounds like it might work. But would you need to continuously do that to prevent if from picking up your real BG? How often would you calibrate it?
Eventually it might become enough of a burden, that it would remove any potential benefit of using auto-mode. I mean, if you need to test every couple of hours and enter that number into your pump, why not just manually adjust your pump every few hours and not use the auto-mode?
The fact that Medtronic got approved with it as 120 and 150 targets is a potential issue for every other pump company that is trying to do that. For example, if Tandem tries to get approved for a 100 target, the FDA might just have the attitude that 120 is now the “standard”.
I use the Omnipod. There is no “fixed target”, you set your own. My target is 5.4, therefore I don’t need to fudge my numbers. Even if my glucose is 7.5, my PDM will adjust it so that it lowers a bit to meet my target. Maybe you should change insulin pumps to make your life easier?
I was told by the Medtronics rep in our area that there are many patients using some method to get lower targets and still use Auto mode. She did not expand on the details, though told me she could do that if I get the pump (I’ll believe that when it happens), or direct me to someone who can.
In my case, my Animas warranty ends too soon to qualify for a free or (for me) affordable upgrade, so I am waiting out the warranty and hoping that either better options or better information becomes available in the interim.
When I first met with my Mdt rep to have a detailed look at the pump before deciding to go with it, I asked this directly. He allowed as how you could effectively approximate a lower target by setting a lower threshold for pause-before-low, though I never tried it. Fooling with calibration readings seems dubious to me pretty much for the reasons you state in the OP: no one but the software engineers really knows how calibration input gets integrated into whatever algorithm produces the readings.
It occurs to me that this falls into the same area as the technique of “phantom” carbs–telling it you’re consuming carbs when you aren’t in order to force it to give you what is effectively a manual correction bolus, something you’re locked out of doing in automode. I never tried any of these fudging techniques in the six months I tried auto because it raised the question, “Then why use auto mode anyway?” There are some answers to that question, especially for people who need protection from overnight lows or other chronic problems, but in my case I decided the many additional hassles weren’t worth the benefits, so rather than trying to fool auto into doing what I wanted by manually screwing around with it, I just went back to my old manual pump.
