However, the researchers, using infrared laser light applied on top of the skin, they measure sugar levels in the fluid in and under skin cells to read blood sugar levels.
"This opens the fantastic possibility that diabetes patients might be able to measure their glucose level without pricking and without test strips. Our goal is to devise an easier, more reliable and in the long-run, cheaper way to monitor blood glucose," lead researcher, Werner Mantele, of Frankfurt's Institut fur Biophysik, Johann Wolfgang Goethe-Universitat, said.
Their new optical approach uses photoacoustic spectroscopy (PAS) to measure glucose by its mid-infrared absorption of light. A painless pulse of laser light applied externally to the skin is absorbed by glucose molecules and creates a measurable sound signature that Dr. Mantele's team refers to as "the sweet melody of glucose." This signal enables researchers to detect glucose in skin fluids in seconds.
The data showing the skin cell glucose levels at one-hundredth of a millimeter beneath the skin is related to blood glucose levels, Mantele said, but previous attempts to use PAS in this manner have been hampered by distortion related to changes of air pressure, temperature and humidity caused by the contact with living skin.
To overcome these constraints, the team devised a design innovation of an open, windowless cell architecture which is still experimental.
The study is published in Review of Scientific Instruments.