There is a lot of research underway into finding an effective and practical way to monitor blood glucose levels non-invasively. reports on a paper authored by researchers at Israel’s Bar-ilan University and published in the journal Biomedical Optics Express.

The Bar-ilan researchers have developed a device that uses a laser to generate a wavefront of light that illuminates a patch of skin near an artery. When laser light reflects from an uneven surface, or scatters from an opaque material, it creates interference patterns that can be imaged. This backscattered “speckle effect” is captured by a camera in the device. Glucose molecules exhibit the Faraday effect: light’s plane of polarization alters when a magnetic field is applied to it (the device incorporates a magnet as well as the laser and camera). The Faraday effect created by the presence of glucose flowing through the illuminated artery alters the backscattered speckle patterns. By analyzing the pattern changes over time, glucose concentration can be determined.

The researchers believe that their system can be developed into a wrist-worn device. This is further indication that the medical devices of the future will incorporate technology that allows them to be truly non-invasive.