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Non-Invasive Glucose Sensor Offers Hope to Diabetics : Health: The device would test blood sugar level without drawing blood. It would use near-infrared light to look inside the body.


ALBUQUERQUE, N.M. — John DeMoss is used to losing blood.

In fact, the University of New Mexico technician loses some blood at least three times a day.

DeMoss is a diabetic, so measuring his blood sugar level--a process that requires a sample of blood--is a regular part of his daily routine.

And he says he's as interested as any diabetic would be in a device that could test his blood sugar level without drawing blood to do it.

As a technician in the physics and astronomy department at the university, DeMoss is assisting researchers at Sandia National Laboratories and the University of New Mexico School of Medicine in developing a non-invasive glucose sensor.

"I've been doing diabetic research studies for 20 years now. . . . In fact, I was the first person to try the New Mexico version of the insulin pump," DeMoss said.

That insulin pump was developed in the 1970s by a Sandia-UNM research team. The small device supplies the insulin that diabetics lack and is planted in a person's body. It is being tested in about 700 patients worldwide.

Now researchers have come up with a blood sugar monitor that uses infrared spectroscopy, a technique used to study the properties and chemical composition of a substance--in this case, body tissue.

The device uses near-infrared light to provide a look inside the human body. Near-infrared light has slightly longer wavelengths than visible light, enabling it to penetrate tissue.

A finger is inserted into a hole in the device's monitor, and portions of the light at each of the various wavelengths is absorbed by the tissue and the blood. The light is then dispersed into a spectrum and glucose concentrations can be determined.

DeMoss and his boss, technician Jim Hontas, have been working with researchers for several years in developing the device that enables the light to pass through the finger. They have just completed different finger holders for it, Hontas said.

An estimated 14 million Americans have diabetes, a disease in which the body does not produce or properly respond to the hormone insulin. It can result in high blood sugar that can damage the heart, blood vessels, kidneys, eyes and nerves.

Many diabetics test their blood sugar levels before each meal and before bedtime. Using current technology, a hand-held instrument called a Glucometer, diabetics prick one of their fingers with a needle and draw the blood. The blood sugar level is measured by the instrument.

A normal blood sugar reading is between 50 to 150.

If a diabetic has a level below 50, DeMoss said, he or she must eat or drink something with sugar in it or be in danger of experiencing insulin shock. If the level is above 150, a diabetic needs an insulin injection to bring the level down.

The glucose sensor now is the size of a large microwave oven and not nearly as perfect as the researchers would like it to be, said Dave Haaland, an infrared spectroscopist at Sandia who has worked on the project for nearly five years.

"It's been a slow process but quite challenging," Haaland said. "I first thought there was just a small chance for success, but we've made breakthroughs that have improved it."

Dr. Ries Robinson, who began work on the glucose sensor during his residency at the school of medicine about 4 1/2 years ago, said researchers are trying to make the device practical for hospital use.

A final instrument would have to cost close to or under $100, the cost of a Glucometer, for it to be practical for an individual diabetic, DeMoss said.

Researchers also want the device to have a greater sensitivity to glucose, Haaland said. The measurement of sugar in the blood is somewhat difficult because of the presence of water, cholesterol and other substances in the blood.

But when researchers perfect the device, its largest impact will be for individual diabetics, Haaland said.

"Diabetics will be able to monitor their blood sugar levels very frequently," he said. "They're doing it now but they have to prick their fingers. Because of that, many don't do it as much as they should."

Both Sandia and the university have transferred their ownership of the sensor to Rio Grande Medical Technologies, a company founded by Robinson.

He has taken a sabbatical from his position in the university's department of medicine to pursue the marketing and further development of the sensor.

Robinson, who declined to disclose how much development has cost so far, said as many as 100 companies are interested in helping to fund the sensor.

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