A laser device could effectively measure diabetics' blood sugar and allow them to avoid pricking their fingers.
The method has already been demonstrated to be effective, and researchers are now working to reduce it down to a smaller size, Princeton University reported.
"We are working hard to turn engineering solutions into useful tools for people to use in their daily lives," said Claire Gmachl, the Eugene Higgins Professor of Electrical Engineering and the project's senior researcher. "With this work we hope to improve the lives of many diabetes sufferers who depend on frequent blood glucose monitoring."
Researchers were able to measure blood sugar by directing a specialized laser at a person's palm. The laser harmlessly passes through the subject's skin and is absorbed by sugar molecules, the rate of absorption allows researchers to measure blood sugar with 84 percent accuracy.
"It works now but we are still trying to improve it," said Sabbir Liakat, the paper's lead author.
When the device was first created it needed an elaborate cooling system to function; the setup was large enough to fill an entire workbench. The researchers say they have solved the cooling problem and are working to shrink down the system entirely.
Laser frequency is the key to the method's success, it uses mid-infrared light which is not affected by the body's chemicals. The problem is this type of light is difficult to harness with standard lasers and requires high power in order to penetrate the skin.
The researchers were able to effectively overcome these obstacles using a quantum cascade laser, which can produce mid-infrared frequencies. In this type of laser the electrons pass through a "cascade" of semiconductor layers that can be set to different frequencies. The ability to adjust frequencies allows researchers to set it to a mid-level range.
To test the device the researchers looked at the blood sugar of three healthy people before and after they each ate 20 jellybeans; they backed up the reading by administering finger-prick test. The team determined the laser method was less accurate than a finger-prick test, but still clinically sound.
"Because the quantum cascade laser can be designed to emit light across a very wide wavelength range, its usability is not just for glucose detection, but could conceivably be used for other medical sensing and monitoring applications," Gmachl said.
The findings were published June 23 in the journal Biomedical Optics Express.
