Although folks tend to remember the big achievements in medicine -- like, say, the discovery of penicillin -- the reality is usually far more evolutionary than revolutionary. The first stents were arguably no better than coronary bypasses, but today's drug-eluting stents are quite good. Likewise with the care and treatment of depression -- today's medications are more precise and present a better risk/benefit trade-off than the options of 25 years ago.

With that in mind, it might be easy for some folks to ignore what Medtronic (NYSE:MDT) is trying to do in the care of diabetes. Today's announcement that the Food and Drug Administration approved the company's Guardian real-time monitoring system isn't going to change the course of diabetes treatment, but it's another positive step down that path.

Many (though not all) people with diabetes have to test their blood glucose levels one or more times a day. That's why you see companies such as Abbott Labs (NYSE:ABT) and Johnson & Johnson (NYSE:JNJ) advertising their glucose-monitoring devices on TV so much -- millions of users times multiple tests per day means a big market.

The world of blood-glucose testing has changed a lot over the past 10 years or so -- today's devices are more accurate, more convenient, and less painful to use. But they're still hampered by the reality that a blood-glucose measurement reflects only one moment in time. That's what devices like the Guardian are here to change.

The Guardian uses a small sensor beneath the skin to measure the glucose in a user's interstitial fluid. It tests this fluid about every five minutes, and a single sensor works for three days before it needs replacing. During that time, though, the user can monitor how his or her blood glucose level changes and can also make use of alarms that will sound if the glucose level is too high, too low, or changing too rapidly.

This isn't a perfect device; it needs to be calibrated every 12 hours, and the device's label states that users must use a traditional finger-stick test to make any adjustments in therapy (meaning insulin administration). But you have to crawl before you can walk, and the FDA is notoriously conservative on new devices pertaining to glucose monitoring.

What this is, though, is a step along the way to a vision of better diabetes care -- including the possibility that there may one day be an integrated monitoring and insulin pump system that effectively mimics the function of the pancreas. With leadership on both sides of that equation (real-time monitoring and insulin pumps), Medtronic is taking a step-by-step approach to fundamentally altering the care of a major and serious disease.

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Fool contributor Stephen Simpson owns shares of Johnson & Johnson but has no financial interest in any other stocks mentioned (that means he's neither long nor short the shares). The Motley Fool has a disclosure policy.