If people with diabetes Type I and Type II don’t monitor their blood glucose levels regularly, meaning multiple times each day, the consequences can include heart attacks, coma, blindness, and even death. Invasive self-testing, usually with finger pricks to draw blood, is a constant reminder of the disease. Measurements from drawn blood are more accurate than finger pricks but at the cost of much greater inconvenience and invasiveness. In 2015, approximately 23.1 million people — 7.2% of the U.S. population — were diagnosed with diabetes according to the CDC. For the vast majority of those people, painful finger pricks are a daily reality.  We’ve written about work on pain-free, non-invasive glucose monitoring by groups around the world including Nemaura’s sugarBEAT and Integrity Application’s GlucoTrack. One of the goals is to use light to detect glucose levels, but many researchers remain skeptical that this can be achieved.

Researchers from the University of Missouri School of Medicine and MIT are testing laser technology called Raman spectroscopy to measure blood glucose without drawing any blood. Early evaluations published in Analytical and Bioanalytical Chemistry show positive predictive accuracy in line with finger prick tests. In Raman spectroscopic testing, a fiber optic cable attached to a wristband wearable measures wavelengths associated with blood glucose by shining laser light directly on the skin. The light also detects fat tissue, protein, and collagen, but the shifts in wavelengths create what the researchers refer to as “a sort of molecular fingerprint” to determine glucose levels.

The testing in the Missouri Medical School and MIT testing involved 20 healthy subjects who did not have diabetes. Moving forward, the researchers’ next steps include testing patients who have diabetes. With continued positive findings, the focus will then move to smaller and more portable test equipment. This could be much more difficult than using the relatively simple LEDs that are used in current fitness bands and smartwatches. Today it may seem a huge leap to embody Raman spectroscopic testing in a wearable device, but it’s too early to bet against it.