German researchers have developed an innovative approach for measuring blood glucose levels in diabetic patients.

One of the keys to healthful living with Type 1 and Type 2 diabetes is monitoring blood sugar levels to ensure they remain at stable levels.

People can easily and reliably do this at home using electronic devices that read sugar levels in a tiny drop of blood.

Now, scientists from the Johann Wolfgang Goethe-University’s Institute for Biophysics and a German industry company have devised a novel, non-invasive way to make monitoring easier.

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.

Their approach uses photoacoustic spectroscopy 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 the researchers refer 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, but previous attempts to use photoacoustic spectroscopy in this manner have been hampered by distortion related to changes of air pressure, temperature and humidity caused by the contact with living skin,” explained Dr Werner Mäntele, the senior author of a paper published in the journal Review of Scientific Instruments.

To overcome these constraints, the scientists devised a design innovation of an open, windowless cell architecture. While it is still experimental and would have to be tested and approved by regulatory agencies before becoming commercially available, they continue to refine it.

In a close collaboration with an industry partner, they expect to have a small shoebox-sized device ready in three years, followed by a portable glucometer some years later.

______

Bibliographic information: Miguel A. Pleitez et al. 2013. Windowless ultrasound photoacoustic cell for in vivo mid-IR spectroscopy of human epidermis: Low interference by changes of air pressure, temperature, and humidity caused by skin contact opens the possibility for a non-invasive monitoring of glucose in the interstitial fluid. Rev. Sci. Instrum. 84, 084901; doi: 10.1063/1.4816723