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.
A couple things - the insulin currently on the market works too slowly for a pump right now to fully close the loop – this functionality – notifying the pump of exercise and eating is part of the user control needed in a "hybrid closed loop" such as this. The user's insulin sensitivity given before, during or after exercise are very different than at other times. Different types of exercise affects body differently as well –HIIT for example raises blood glucose for a couple hours during and after – and then will significantly increase the sensitivity to insulin and many type 1's will drop rapidly. Aerobic activity will tend to drop blood glucose rapidly on it's own. Notifying the pump allows you to drop the levels given – something users do on their own now.
It's a great step – looking forward to the options coming in the next couple years with Bigfoot & ILet. Glad to see this on HN – made me finally comment.
We should be complete building my husband's artificial pancreas next week based on open source code. For those interested in what's happening in the community – you might want to take a look at openAPS.
