Patch Painlessly Tests for Glucose in Diabetics

A skin patch could one day provide a less-invasive alternative for diabetics who need to take regular samples of their own blood to keep glucose levels in check.

The patch, approximately the size of a deck of cards, contains four micro-needles that "bite" sequentially at programmed intervals. The needles are electronically controlled to penetrate the skin deep enough to draw blood from a capillary, but not deep enough to hit a nerve. This means patients would experience little or no pain. The patch could be worn anywhere on the body where it could obtain accurate readings of capillary blood.

Electrical engineers from the Schulich School of Engineering at the University of Calgary (Alberta, Canada) have patented the device, which they dubbed the Electronic Mosquito. A sensor in each cell of the e-Mosquito measures sugar levels in the blood. These data can then be sent wirelessly to a remote device such as a computer or a monitoring instrument worn on the wrist. The system could even be connected to an alarm to alert patients or doctors when blood sugar levels enter the danger zone. The currently used method of drawing blood from fingertips and using glucose-testing strips can be painful, inconvenient, and time-consuming.

"This is a dramatic improvement over manual poking, particularly for children and elderly patients," said Martin Mintchev, director of the Low Frequency Instrumentation Lab at the Schulich School of Engineering. "Our approach is radically different and offers a reliable, repeatable solution with the minor inconvenience of wearing something similar to an adhesive bandage."

Eventually, the biomedical engineers intend to integrate a pump system so insulin injections can also become autonomous based on data from the e-Mosquito, thus converting the device into an external artificial pancreas.

Approximately 246 million people around the world are affected by diabetes. More than two million Canadians have diabetes, a number that is increasing because of the aging population and rising obesity rates, according to the Canadian Diabetes Association.

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Schulich School of Engineering at the University of Calgary