Originally Posted by sstorkel

I've been using an insulin pump since 1981 or '82. For that entire time period, researchers have been predicting that a closed-loop system was only 5 years away. I currently use a continuous glucose monitoring system. Accuracy and reliability are nowhere near good enough to allow implementation of a closed-loop system.

In addition, current (external) insulin pumps seem like a poor match for a closed-loop system. Insulin injected subcutaneously takes hours before it reaches peak effectiveness. That simply won't work for a closed-loop system, which is designed to monitor your blood sugar and then deliver insulin to compensate for any changes without any intervention from the user. The long lag between the time when a blood sugar spike is detected and effective insulin can be delivered would mean that the system is always "chasing its tail". A closed-loop system would need insulin that reaches peak effectiveness an order of magnitude faster or an implantable pump that delivers insulin to the blood stream much faster.