LONDON (TIP): A new biometric wristwatch is being developed that can monitor your blood glucose, dehydration and pulse rate. In a pair of papers published in The Optical Society, researchers from the Netherlands and Israel described two new wearable devices that use changing patterns of scattered light to monitor biometrics: one tracks glucose concentration and dehydration levels while the other monitors pulse.

Monitoring a patient’s vital signs and other physiological parameters is a standard part of medical care but increasingly health and fitness-minded individuals are looking for ways to easily keep their own tabs on these measurements. The glucose sensor is the first wearable device that can measure glucose concentration directly but noninvasively, the authors said.

And while other wearable devices have been made to monitor pulse, the authors claim their new design would be less sensitive to errors when the wearer is in motion. The devices use the so-called 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 speckle pattern changes with changes in the flow,” said biomedical engineer Mahsa Nemati from the Delft University of Technology.