Researchers from the Massachusetts Institute of Technology’s Spectroscopy Laboratory are working on a non-invasive way for people with diabetes to measure their glucose levels using light.
The experimental device has a cable with a tiny bulb on the end which is held next to the skin on the arm. This then shines a type kind of light – called a near-infrared light – into the tissue underneath the skin.
Light waves reflect off glucose
This light then reflects off glucose circulating in the interstitial fluid – a type of liquid that bathes skin cells and which is found just beneath the skin surface. The light waves pick up tiny vibrations in the molecules that hold glucose cells together, a technique called spectroscopy. As these vibrations occur at a different rate in glucose compared with other fluids in the body, the light can identify glucose molecules accurately. A computer program then converts this into a reading estimating what blood glucose levels would be.
Algorithm used to predict glucose levels
One of the major obstacles they have faced is that near-infrared light penetrates only about half a millimetre below the skin, so it measures the amount of glucose in the interstitial fluid, not the amount in the blood. To overcome this, the team came up with an algorithm that relates the two concentrations, allowing them to predict blood glucose levels from the glucose concentration in interstitial fluid.
The US team is working on a laptop-style device that can be used by doctors to check patients. They also hope to develop this technology into a handy gadget which people with diabetes can carry with them as an alternative to daily blood tests.
We will be monitoring progess closely
"This is good research that has been ongoing for some time. The researchers know that they need to produce a monitor which can accurately predict the levels of glucose in the blood and they have progressed well with that," explained Dr. Iain Frame, Director of Research at Diabetes UK.
"The device will need to be small enough for people with diabetes to be able to use and carry, and which is cheap to produce. We will be monitoring their progress closely," he added.