By Tracking Sugar In Tears, Contact Lens Offers Hope For Diabetics

Jan 17, 2014
Originally published on April 20, 2016 1:36 pm

The latest project from Google X is a smart contact lens, a tiny, flexible computer capable of monitoring glucose levels in tears. Researchers at Google are hopeful that one day this technology might be used to help diabetes patients better control their disease.

"I think the Google X device could be a huge game changer," says Dr. John Buse, professor of medicine at the University of North Carolina School of Medicine. He's also chairman of the National Diabetes Education Program for the National Institutes of Health and the Centers for Disease Control and Prevention.

Buse and Google researchers are quick to point out that years of basic research remain before this device or one like it comes to market. At the moment, even the relationship between the level of glucose in tears and blood glucose levels remains unproven.

Nonetheless, the tiny wireless computer embedded on a soft contact lens represents a remarkable technical achievement.

Scientists at Google unveiled their prototype Thursday.

"At this point, we have functional prototypes," said Brian Otis, the project lead at Google X. "We have integrated circuits that have been miniaturized to the point where they look like a piece of glitter integrated inside the soft contact lens material."

The smart lens consists of this glitter-fleck-sized wireless computer chip as well as a microscopically small glucose sensor and an antenna thinner than a human hair. All of this is embedded between two layers of soft-contact lens material.

"We have a glucose sensor that has to be much more sensitive — because the concentration of glucose in tears is much lower than the concentration in blood. We've also created a way of tying all of these technologies together in a flexible platform," Otis said — so flexible and soft that you could slip it over your eye.

This device is powered by harvesting radio waves from the air. A minute capacitor harvests RF power and creates a little bit of static electric charge on the chip. The chip itself uses just one microwatt of power to operate. That's one one-millionth of the amount of power required by your phone.

"This is a really exciting problem because it pushes the limits of miniaturization, which is something we've been interested in pushing for a really long time," Otis said.

Otis and Babak Parviz began this research at the University of Washington years ago. Using National Science Foundation funding, they developed a mock-up smart lens on hard plastic.

While no one could have worn that prototype, they convinced themselves that a real, wearable device might be technically possible. However, they faced another enormous hurdle. Because measuring glucose levels in tears is difficult, no one had established a correlation between those levels and blood glucose levels.

"That's one of the things that makes Google X a unique place — we were able to embark on this project even though we had these two big questions at the beginning," Otis said.

One, could they build a lens to do this?

And two, if they did, would it measure something that actually matters?

Now that they have built a lens that works, they can begin doing basic research to learn whether the lens might someday help diabetics better control their disease.

Buse said if a device like this works, it could transform care for patients with Type 1 diabetes, who have to monitor their blood sugar levels multiple times a day. He is hopeful that a noninvasive way can be developed to help those with Type 2 diabetes monitor their blood sugar as well.

"There has always been a notion that if people really knew what their blood sugar was, and how their blood sugar related to the food that they eat and their exercise, it would allow people to gain more insight into their disease and make better decisions," he said.

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This is Morning Edition from NPR News. Good morning. I'm Steve Inskeep.


And I'm Renee Montagne. A California driver beat an unusual traffic charge yesterday, by employing a high-tech defense. She had been ticketed for driving with Google Glass, the eyeglasses that carry a tiny computer you can use for things like checking email. A police officer pulled her over for speeding and noticed she was wearing the special glasses.

INSKEEP: California forbids drivers from turning on video screens in the front of the car while driving, except for things like navigation. But the driver, among thousands of people chosen to test this product, argued that her glasses were not turned on. And the San Diego traffic court ruled that police had not proven otherwise.

MONTAGNE: Also yesterday, Google's research branch, Google X, unveiled and even smaller computer. This time it is on a contact lens. The soft lens contains a tiny flexible computer that monitors the glucose levels in tears. NPR's Steve Henn reports that if it works it could save diabetes patients thousands of pin pricks and blood tests.

STEVE HENN, BYLINE: Dr. John Buse is a professor of Medicine at North Carolina and chairs the National Diabetes Education program for the National Institute of Health. Although he just found out about Google's smart contact lens project a week ago, he's pretty excited about it.

DR. JOHN BUSE: I think the Google X device could be a huge game changer.

HENN: He says for years, diabetes researchers and practitioners have been looking less invasive ways to monitor blood glucose levels. Taylor Degroff was diagnosed with Type 1 diabetes as a little kid.

JENNIFER SCHNEIDER: Taylor was two years old.

HENN: That's Taylor's Mom, Jennifer Schneider. How many finger sticks do you think Taylor has had in the course of her life?


HENN: Taylor's body makes no insulin on its own.

SCHNEIDER: I'm going to try to do the math. We check 10 times a day, on average.

HENN: Ten times a day, 365 days a year, for 11 years - that's more than 40,000 finger pricks. And one of the reasons her parents test so much is that a mistake - too much insulin - not enough sugar - can be fatal.

SCHNEIDER: It's hard. Every night we worry.

HENN: The family recently got a continuous glucose monitor that Taylor now wears on her thigh. It involves needles and a wire under Taylor's skin. It's expensive, but it monitors her blood sugar levels around the clock and will trigger an alarm when levels get too low. Jennifer Schnieder says it's made a big difference in their lives. What Google announced yesterday is that it's taken similar technology, miniaturized it, and put it inside a soft contact lens.

BRIAN OTIS: You know, at this point we have functional prototypes.

HENN: That's Brian Otis, the smart contact lens project manager at Google X. Can I try one on?

OTIS: We have devices that are ready to wear - unfortunately, you are not enrolled in one of our studies, but I wish you could.

HENN: And then, just to rub it in, Otis opens a contact lens case.

You are taking it out.

OTIS: I want to show you one of our prototypes.

HENN: It looks and feels like a normal contact lens - almost.

OTIS: There we go. A few things that you will notice...

HENN: There two gold lines - actually the antenna - rimming what would be the iris of the wearer. But to see computer inside this contact lens, you really need a microscope. So Otis brings one out.

OTIS: All of these components are thinner than a human hair. The square in the middle is the integrated circuit that contains tens of thousands of transistors.

HENN: That looks just like a single flake of glitter to the naked eye.

OTIS: And that connects directly to the glucose sensor next door.

HENN: Picture slim circuits that look like thin interlocking fingers.

OTIS: There is a pin hole in the contact lens that allows the tears to approach the sensor.

HENN: Now, no one knows if measuring glucose levels in tears will really work as a proxy for blood glucose levels in diabetics. There are years of research and tests ahead. And a smart contact lens aimed at helping diabetics may never make it to market - but nonetheless simply shrinking the electronics involved in this thing is remarkable. To do it, the team at Google X created integrated circuit - a full-fledged a computer chip capable of complex calculations and then built that onto a flexible piece of plastic that is the size single flake of glitter. Otis places one on my fingertip.

OTIS: Can you feel it?

HENN: No, I can't feel it at all. What would you say, three ridges in my fingerprint?

OTIS: Yeah, that's about right.

HENN: It's possible to imagine almost infinite uses for sensors and chips this small but Brian Otis says for now his team at Google X is focused on a single one - someday giving diabetics a less painful way to manage their disease. Steve Henn, NPR News, Silicon Valley. Transcript provided by NPR, Copyright NPR.