Continuous glucose monitor (CGM) technology has become available in stages over the past decade or so, and the technology continues to improve. The first commercially available system widely available was the Glucowatch, a system that did not require the skin to be broken but that most people found unreliable. Over the past 4 to 5 years, several other commercial systems have become available which require a catheter to be inserted through the skin but which yield much more reliable results. Commercial systems are available from MiniMed Metronic, which integrates its CGM with their insulin pump system, though for now the person with diabetes still has to manually control pump dosing. The Dex-Com corporation is working with the Animas insulin pump company to develop a similarly integrated system. Abbott Laboratories has a system which has had some recalls and order backlogs, but which some users have found satisfactory.
The present systems work fairly well in many people, but I would say they are all still not quite ready for prime-time, meaning we are still waiting for systems that are easier to use, more reliable and less expensive. And of course the Holy Grail is a fully integrated "closed loop" system or "artificial pancreas." Such systems are in clinical trial, but it will be several years at least until they are available. Nonetheless, the present systems are a major advance and extremely useful, especially for those with type 1 diabetes who have volatile blood sugars.
More Answers from Jack Merendino, MD