Glucose Meters: What's on the Horizon?
Contact lenses, tattoos, infrared light, and smart sensors will detect your glucose level in the "ouchless" future.
By Jeanie Lerche Davis
Reviewed By Charlotte Grayson
If you've got diabetes, regular blood glucose (sugar) testing is a fact of life. And getting your all-important glucose level has become easier. Today's glucose meters are more sensitive, and require less blood -- which likely equates with less pain. That advance has been a big one for people with diabetes. But will the "ouch" ever go away?
Researchers are hard at work -- developing special contact lenses, fluorescent "tattoos," infrared devices, and smart sensors to decipher your glucose levels -- with them being "ouchless" as their goal. In some cases, no blood testing is required -- maybe one prick at the most.
Guenther Boden, MD, chief of endocrinology at Temple University School of Medicine, has monitored developments in this field over the last few decades.
"The GlucoWatch Biographer seemed like the answer," Boden tells WebMD. "The underside of the watch has a membrane that can suck interstitial fluid through the skin; get 'juice' out of skin, so to speak. And that's what you need to measure glucose; you need to get some body fluid. The technology seems to work. But skin irritation has been a problem for some people."
That problem is being corrected, says Audrey Finkelstein, a spokeswoman for Animas Corporation, the product's maker. "We are presently working on Biographer III, which will combine the Biographer with tiny microneedles that will extract fluid to provide a better blood sample than is possible with other technologies. It will also greatly reduce or even eradicate skin irritation."
Products like GlucoWatch are good at alerting patients to impending danger -- especially necessary during sleep hours. "It's a dangerous thing for people to buy a product like this, thinking they won't need to do finger sticks anymore ? You simply can't replace finger stick testing if you want to be safe and healthy," Finkelstein tells WebMD.
Another device that tracks glucose trends -- Medtronic's continuous glucose monitoring device, the "Guardian," which received FDA approval in February 2004. That device isn't very patient-friendly, says Boden. It provides data that is downloadable by physicians, so that 72-hour glucose trends can be monitored. But patients don't get any immediate readings. Also, measurements during night hours have been inaccurate. Medtronic "is working very hard to solve that problem," Boden tells WebMD.
Indeed, a refined version of that device is in clinical trials in Europe right now, says Deanne McLaughlin, of Medtronic Diabetes. Continuous glucose monitoring "has given patients a better understanding of the impact of their treatment, diet, and activity levels on their glucose levels," McLaughlin tells WebMD. Regarding the refined device, "we are very excited about 'real-time' readings and the potential ? for helping patients improve their blood sugar control."
Beyond that, "We're really still at the finger-sticking stage," Boden tells WebMD. "There are a zillion different machines to measure blood, and they have gotten better. The biggest advance is that the new types use much less blood. That means you don't have to stick your finger -- you can stick the underside of your arm, where it doesn't hurt. The pain sensors in your arm are very far apart, whereas they're very dense in your fingertip. That's made the biggest difference."
As for new meters in the development pipeline, the jury is still out. Here are a few that caught our attention.
See It in Your Eyes
Like the 1970s mood rings, your contact lenses could someday reflect your glucose level. With one glance in a mirror, you'll see whether you're headed for trouble.
This eye-opening innovation has been a 20-year-long project headed by Sanford Asher, PhD, professor of chemistry at the University of Pittsburgh Medical Center. "We're making great progress," Asher tells WebMD. "We expect to go to the FDA in another year. We're not sure how extensive clinical trials will need to be, given the experience with soft contact lenses."
Here's how it works: A thin plastic sensor is embedded in a typical soft contact lens; the type you replace weekly, explains Asher. The sensor detects the amount of glucose in the tears -- and changes color accordingly. On the eye, the sensor appears as a slim crescent of color in the lower area of the iris, below the pupil -- a hint of green (normal), blue (hypoglycemic - low blood sugar), or violet (very hypoglycemic). Other colors reflect high blood sugar levels, or hyperglycemia.