When we think about Medtronic MiniMed, insulin pumps usually come to mind. That makes sense, because MiniMed was among the first to market an insulin pump and today dominates the U.S. market with more than a 70 percent share.

Medtronic MiniMed’s monitor business is much less well known, but it will potentially help many more people with diabetes. The company was the first to offer a monitor to continuously sense glucose levels in interstitial fluid, the Continuous Glucose Monitoring System or CGMS.

The CGMS has serious limitations. Although it records glucose levels every five minutes for up to three days, it’s not really a home unit, because you have to go to your doctor’s office to download the readings.

With its second monitor, the Paradigm Link, Medtronic MiniMed connects pumps and monitors for the first time. This is the first monitor for wireless communication with insulin pumps, the Paradigm 515 and 715 pumps.

The Paradigm Link is a blood glucose meter, not a continuous monitor. But the CGMS and the Paradigm Link are just the beginning. The company is working now on three more monitors, and all of them will continuously sense glucose levels.

The first of these monitors, the Guardian Continuous Glucose Monitoring System, will probably become available in the next few months. The Guardian will sound an alarm when your glucose levels go too high or too low.

But the Guardian won’t display any readings on the screen or show your glucose trend. That will have to wait for Medtronic MiniMed’s next monitor, the Guardian RT.

Those letters “RT” stand for “real time.” The Guardian RT system is a personal continuous glucose monitoring system, providing realtime glucose values and adjustable alarm levels.

Medtronic MiniMed will sell the Guardian RT only in Canada and Europe. That’s because the company plans to provide an even more powerful monitor here. It doesn’t have a name yet, but the company is referring to it as the “next generation Guardian System.”

This next generation monitor will not only provide real-time results and adjustable alarms for highs and lows, it will also trend graphs. The company will offer it in the United States, Canada and Europe.

Getting it just right takes time. The next generation Guardian won’t be available this year, says Deanne McLaughlin, communications manager for Medtronic Diabetes. Maybe in 2006, she says.

The company’s goal has always been to build a closed-loop artificial pancreas. It will combine an insulin pump with a continuous glucose monitor, which will provide feedback to the pump telling it to deliver just the right amount of insulin in response to the glucose level that the monitor detects. The next generation Guardian will move much closer to that goal.

The Continuous Advantage

Having real-time glucose readings is like watching a feature film for the first time after a lifetime of seeing only still frames. With real-time data, we can learn about the effects of diet and exercise on our glucose control. Furthermore, we can take action earlier to reduce the severity and duration of glucose levels that are too high or too low.

Real-time readings come from monitors, not meters, in Medtronic MiniMed’s terminology. A meter takes a snapshot of your blood glucose level at one point in time. It is random and you can’t be sure when to test. But when you use a continuous glucose monitor, you are testing all the time and get a moving picture that correlates with your life.