What’s the difference between the insulin pump and an artificial pancreas?

There's some mention in the media about artificial pancreas. What's the difference between an insulin pump and this concept of an artificial pancreas? We're getting close to the technology of artificial pancreas but there is a potential limitation with regards to the sensitivity of the sensors that come as part of the closed-loop system. There are currently trials which are happening in Cambridge and University of Virginia but there is a limitation that sensors are not sensitive enough to measure your continuous glucose levels which means that they will either overestimate or underestimate the amount of insulin that they can instruct the insulin pump to have. The best form of insulin pumps are are the ones who can integrate the sensor technology which we have in the form of Medronic 670G now, but we're not very close to artificial pumps yet.