CGMs are amazing, and the closed loop makes the diabetics' life vastly better. They can almost pretend they have a functioning (mechanical) pancreas.
But there's more to be done. They don't measure blood insulin, but the interstitial fluid, which responds more slowly. And a new monitor takes an hour to establish its baseline, which is an hour that your closed loop isn't complete. (I gather that the newest Dexcoms take just 30 minutes.)
A version that used just a smartwatch would be amazing, especially if it really was measuring the actual blood level. But making that sure enough to be part of a closed loop is a massive, massive hurdle. It's controlling the delivery of a medicine where both overdose and underdose are dangerous, and that means extremely high levels of precision and proof.
But there's more to be done. They don't measure blood insulin, but the interstitial fluid, which responds more slowly. And a new monitor takes an hour to establish its baseline, which is an hour that your closed loop isn't complete. (I gather that the newest Dexcoms take just 30 minutes.)
A version that used just a smartwatch would be amazing, especially if it really was measuring the actual blood level. But making that sure enough to be part of a closed loop is a massive, massive hurdle. It's controlling the delivery of a medicine where both overdose and underdose are dangerous, and that means extremely high levels of precision and proof.