Scientists getting closer to artificial pancreas
Jun 27, 2011, 8:23 a.m.
By Julie Steenhuysen
CHICAGO (Reuters) - Researchers are coming closer to developing an "artificial pancreas," a long-sought system of insulin pumps and glucose sensors that deliver insulin to diabetics, mimicking the function of a real pancreas.
The devices have been in development for more than three decades, but lawmakers and diabetes advocates are ramping up the pressure and U.S. regulators this week outlined a regulatory path for a preliminary version of the device.
And while a seamless device that tracks a diabetic's blood sugar and automatically administers the right dose of insulin is still years away from commercial use, results of several studies being presented this week at the American Diabetes Association meeting in San Diego show real promise.
In one, researchers from Boston University and Massachusetts General Hospital tested a system using Abbott Laboratories' FreeStyle Navigator continuous glucose monitor and two insulin pumps made by Insulet Corp, all controlled by a laptop.
The system, which is designed to better mimic the body's natural mechanism of controlling both high and low blood sugar, was portable enough to allow adults with type 1 diabetes to roam around a hospital and use an exercise bike.
At the end of the 51-hour study, which involved daily exercise, two nights and six meals - all of which affect a diabetic's blood sugar levels - six patients had an average blood glucose in the normal range - in the high 140s, which is about the equivalent of an A1c reading of about 7.
"It is very good. This is what we would call near normal blood glucose," said Dr. Steven Russell of Massachusetts General Hospital in Boston who is developing the system with Edward Damiano, a biomedical engineer at Boston University.
In another study, a team at Mayo Clinic hooked patients up with devices called accelerometers that tracked movements and found that even moderate exercise plays a role in glucose. The team, led by Yogish Kudva, will incorporate this data into a sophisticated software program that acts as the "brain" of an artificial pancreas system, analyzing blood sugar and calculating when diabetics need a dose of insulin.
The team plans to start a clinical trial with the system this year or early next year, Kudva says.
CLOSING THE LOOP
So-called closed-loop systems - in which a computer calculates a person's insulin dose and delivers insulin automatically through an insulin pump - are a far cry from the earliest version of an artificial pancreas developed in the late 1970s, says Dr. Aaron Kowalski of the Juvenile Diabetes Research Foundation or JDRF.
"The problem is it was the size of a refrigerator," said Kowalski, who oversees the group's Artificial Pancreas Project, a multimillion-dollar initiative aimed at accelerating progress toward a closed-loop automated insulin-delivery system .
With that device, patients were hooked up to an IV and could not leave their hospital bed.
Researchers have since been working to develop a so-called artificial pancreas to deliver insulin to patients with type 1 diabetes, an autoimmune disease in which the body destroys its own ability to make insulin, rendering sufferers unable to properly break down sugar.