Won’t Feel a Prick

Princeton University researchers have developed a new way to use laser to measure people's blood sugar level, a technique that would allow diabetics to check their condition without pricking themselves to draw blood. The new laser–based device is 84% accurate, the accuracy of which is determined when glucose monitors produce a blood sugar reading within 20% of the patient’s actual level.

Current medical devices use ‘near–infrared’ laser, which is not visible to the naked eye. However, its interaction with many acids and chemicals in the skin makes it impractical to use it for detecting blood sugar. On the other hand, ‘mid–infrared’ light is not affected by these chemicals and hence, it works well for blood sugar. The only drawback is that they are not compatible with standard lasers and hence, require relatively high power and stability to penetrate the skin and scatter off the body fluids. Scientists, therefore, used a quantum cascade laser, a new device that is particularly adept at producing mid–infrared frequencies.

In order to proceed with the experiment, researchers used the device to measure the blood sugar levels of three healthy people before and after they ate 20 jellybeans each. The corresponding results were also checked with the findings of a finger–prick test. This experiment was conducted repeatedly over several weeks wherein the results had minor differences when compared to the finger–prick technique, but the numbers largely remained within the clinical requirement for accuracy.