Tuesday, May 11, 2010

medical tattoos.........

Prescription Tattoos: Coming to a Pharmacy Near You

It might be time for a trip to the tattoo parlor. Medical tattoos could soon monitor key vitals, including glucose levels. By Eric Bland

Fri May 7, 2010 09:09 AM ET

Doctors could soon prescribe tattoos for patients.

Tattoos would monitor glucose levels and protect pacemakers.

The first trials in mice of medical tattoos are promising.

A glucose sensing tattoo would appear different in color to a hand-held device if glucose levels are out of whack.

Getting inked could save your life.

Scientists from Microsoft and The Draper Laboratory are developing medical tattoos that would stop hackers from messing with pacemakers and drastically reduce the number of needle sticks needed to monitor glucose levels.

Medical tattoos could also be adapted to monitor any number of other medically important molecules.

"We can follow the same trends as a finger stick glucometer," said Heather Clark, a scientist at the Draper Laboratory near Boston and a co-author of a recent article in the journal Analytical Chemistry that describes her team's glucose monitoring tattoo.

Clark's medical tattoo isn't a true tattoo. A typical tattoo involves repeatedly sticking a patient with a solid needle that penetrates deep into the skin to permanently stain the tissue with dark colors. Clark's prototype medical tattoo, on the other hand, would use a single stick from a hollow needle to stain the first few layers of skin yellowish orange for about a week.

The yellow-orange dye contains tiny nanosensors, little balls about 100 nanometers across. Glucose is drawn into the heart of the sensors, where it changes the color of a tiny pigment molecule. As the amount of glucose rises, the color of the tattoo would become lighter. As glucose levels fall, the tattoo would get darker.

To the human eye, the change in color would be almost unnoticeable. To a special handheld camera, however, the difference is enormous.

In their article, Clark and her colleagues successfully tracked glucose levels in mice as they rose and fell with their camera. To ensure their readings were accurate, they also measured the amount of glucose in the blood at the same time. The blood glucose levels matched the glucose levels in the skin, which was measured by Clark's tattoo.

Tracking a rising or falling glucose level through the skin is an accomplishment, but without detailed readings the use will be limited for diabetics. Thankfully Clark and her team have also developed nanosensors that give exact measurements of glucose levels in the body, which they plan to test next year.

Within several years, Clark's glucose monitoring tattoo could be on the market, and patients wouldn't have to travel to the wrong side to town either for treatment either.
Clark envisions patients picking up an EpiPen-like device from their local pharmacists and self-administering the tattoo once a week. To read the tattoo, patients would need a cell-phone sized reader, or possible just a cell phone, said Clark. All a diabetic would need to do is pull out their cell phone and take a picture of the tattoo.

"The technology here is very innovative, and in principle it's very promising," said Rexford Ahima, a diabetes research at the University of Pennsylvania.

Ahima notes that human trials would still be necessary before patients are injected with nanosensor tattoos for diabetes, but that eventually the technique could be used for other diseases.

"This may encourage patients, especially type 2 diabetics who often don't check their glucose levels as much as they should, to check their levels more often," and with less pain, said Ahima.

Clark's team at Draper isn't the only group looking to use tattoos for medical purposes. Microsoft Research is also developing tattoos for medical use. In this case, Microsoft is looking into protecting patients with implanted biomedical devices.

"Prior work has shown that some implantable medical devices use wireless protocols that are vulnerable to attacks," said Stuart Schechter of Microsoft Research, who recently wrote a paper detailing how tattoos could stop hackers from altering pacemakers and other implanted devices. Unlike Clark's yellowish orange tattoo, Schechter's tattoo would be invisible to the human eye; only ultraviolet light could detect it.

Schechter's tattoo would contain what's called an access key, essentially a password to access the settings of the biomedical device. Without the access key, no one could hack into the device.

In normal clinical settings, a patient could simply tell a physician what the key is. But in an emergency situation with an unconscious patient, unable to release the access key, an invisible tattoo could provide valuable information to doctors and nurses.

The tattoo might be invisible but a scar is not. Implanting biomedical devices almost always leaves a scar under a person's clothes. In an emergency situation, the clothes would be removed, exposing the scar, and letting emergency personnel that a device could be inside the patient. UV light would expose the alpha numerical password of the patients choice.

Invisible or not, patient's won't be getting inked any time soon. It will take years before medical tattoos are approved for humans, and even more time to develop the infrastructure for clinical use.

But if the tattoos are successful, they could open up new ways to protect and treat patients.