Artificial pancreas and implantable insulin pumps being tested

http://news.bbc.co.uk/2/hi/health/6110472.stmChildren afflicted with type I diabetes in the UK are being recruited for a study involving continuous blood glucose sensors that calculates insulin requirements and controls an insulin pump. This device will not only automate blood glucose management and eliminate the need for routine finger-pricks, it will also provide improved blood glucose control because of its continuous sensing. Studies have found that even patients who measure their blood glucose an average of 9 times a day only spend 30% of the day in their normal glucose range. However, trials have show that continuous glucose sensors can increase the amount of time spent in the normal glucose range by 26%.

http://www.pnl.gov/energyscience/06-01/ws.htm
This article talks about artificial pancreas development in the United States. The information is dated (it's from 2001) but it provides more detail about the sensor mechanism, which uses a molecule that fluoresces when bound to glucose.