There’s word of a major step toward an artificial pancreas, a device that would constantly monitor blood sugar in people with diabetes, and automatically supply insulin as needed.

A key component of such a system, an insulin pump programmed to shut down if blood-sugar dips too low while people are sleeping, worked as intended in a three-month study of 247 patients.

This “smart pump,” made by Minneapolis-based Medtronic Inc., is already sold in Europe, and the U.S. Food and Drug Administration is reviewing it now.

 The study results were presented Saturday at an American Diabetes Association conference in Chicago. They also were published online by the New England Journal of Medicine.