Earnest skepticism: how can you trust Open APS without the rigorous testing required from companies like Medtronic? Sure, FDA regulations are not perfect. But they sure work in a large number of cases. While the DIY spirit of Open APS is commendable, hypoglycemia can be extremely dangerous and the risk is too high without FDA-level rigorous testing.
Here's the inherent problem – insulin is a lot more dangerous on it's own than with any sort of hybrid loop system. The safety having a system like openaps - which includes a LOT of fail safes - is far greater than what a type 1 diabetic can do on their own. 1 in 20 people will die in their sleep because of hypos because he or she simply isn't fortunate enough to feel the blood sugar dipping and wake up to treat. The OpenAps safety measures are far far greater than what we have as a normal person regulating their day-to-day insulin dosing. I will sleep a lot easier knowing that I have something else watching, determining whether the boluses he's given might be corrected slightly so that he doesn't go low or high. Read about it at openaps.org – look at the reference design, and read about the fail safes where the pump will revert back to preprogrammed basal rates if batteries run out. Quite frankly anything with Type 1 diabetes is terrifying. At the end of the day, the risk with type 1 is too high for us to wait any longer.
My understanding based on the link in my sibling comment is that the current commercial systems don't inter-operate and that the diabetic must read from one device, calculate a dosage themselves, and then enter that dosage into a second device. At each of the three stages there is the potential for human error and common circumstances such as performing each task in the middle of the night while suffering the effects of sugar imbalance make errors more likely. Not that such circumstances are necessary for errors because the process is repeated by diabetics on the order of a thousand times a year over decades.
My understanding is that the issue with the device upon which OpenAPS relies is that a bad actor could possibly reprogram it over BlueTooth. Doing so would require close physical proximity to the individual. By close to the point that a bad actor could probably physically harm the individual or gain access to the insulin itself...i.e. to within a few feet.
To put it another way, one problem the with FDA approval is that OpenAPS uses a no-longer-approved device and the reasons it is no longer approved are not based on evidence of increased hypoglycemia. Their related to medical device manufacturer liability and hence the cost of insuring against risk.
Because there's always a trade-off between robustness and usefulness, and it's not at all obvious the FDA hits the right balance, especially given the extremely asymmetric incentives they face. If they approve a drug that kills a bunch of people, the repercussions are bad, but if millions die while waiting for a drug to undergo a decade of testing, the FDA isn't blamed.
* I can read the code. It's not very complex.
* There are minimal moving parts.
* I can suspend the pump or disconnect at anytime.
* It's changing my basal rates (minor adjustments) not randomly bolusing large amounts. This isn't an "overdose" type situation.
* I'm fully in control of my facilities. I'm not a child or an older person - each of which are more likely to have hypos.
* I have never had a debilitating hypo in 20 years, I'm not planning on having one now.
* The system was designed by diabetics, for diabetics. The closed systems that will come out like Medtronics will be VERY conservative. So much so as to be of questionable use to folks who want an A1C <6%
Because of all these reasons, along with 15+ years of pumping alone and doing the calculations in my head (and getting them wrong) I choose to trust these systems.
