Watches to monitor glucose, dehydration, pulse soon

What if a watch can monitor a patient's vital signs and other physiological parameters?

Researchers from the Netherlands and Israel have developed two new wearable devices that use changing patterns of scattered light to monitor biometrics.

While one device tracks glucose concentration and dehydration levels, the other monitors pulse.

The glucose sensor is the first wearable device that can measure glucose concentration directly but non-invasively.

"Glucose is the holy grail of the world of biomedical diagnostics and dehydration is a very useful parameter in the field of wellness, which is one of our main commercial aims," explained bioengineer Zeev Zalevsky from Israel's Bar-Ilan University.

The watch-like device consists of a laser to generate a wavefront of light that illuminates a patch of skin on the wrist near an artery.

It has a tiny camera that measures changes over time in the light that is backscattered off the skin.

Analyzing changing patterns provides a direct measurement of the glucose concentration.

"Because one of the main signs of mild to moderate dehydration is muscle weakness, which will alter the strength of the signals, the same device can also be used to indicate the relative dehydration level of the user as it changes over time," Zalevsky informed.

The team expects a commercial version of the device to reach the market within two to three years.

"The other device will monitor pulse and the new design would be less sensitive to errors when the wearer is in motion, for example while walking or playing sports," said biomedical engineer Mahsa Nemati from Delft University of Technology in the Netherlands.

Both the devices make use of the "speckle" effect - the grainy interference patterns that are produced on images when laser light reflects from an uneven surface or scatters from an opaque material.

The papers were published in the open-access journal Biomedical Optics Express.