Researchers have developed a small non-invasive device by combining radar and artificial intelligence (AI) technologies that would help people with diabetes to monitor their blood sugar levels without the need for painful finger pricks several times a day.

"We want to sense blood inside the body without actually having to sample any fluid," said lead author George Shaker, professor at the University of Waterloo in Canada.The system can detect changes in sugar levels using a small radar device which sends high-frequency radio waves into liquids containing various levels of glucose and receive radio waves that are reflected back to it.Information on the reflected waves is then converted into digital data for analysis by machine-learning AI algorithms developed by the researchers.The software is capable of detecting glucose changes based on more than 500 wave features or characteristics, including how long it takes for them to bounce back to the device.

Initial tests with volunteers achieved results that were 85 per cent as accurate as traditional, invasive blood analysis. "The correlation was actually amazing. We have shown it is possible to use radar to look into the blood to detect changes," Shaker said, in the paper detailed in the International Journal of Mobile Human-Computer Interaction. Next steps include refining the system to precisely quantify glucose levels and obtain results through the skin, which complicates the process.

Researchers are also working to shrink the radar device so that it is both low-cost and low-power.The data analysed by AI algorithms is now sent wirelessly to computers, but the ultimate aim is self-contained technology similar to the smartwatches that monitor heart rate."Our hope is this can be realised as a smartwatch to monitor glucose continuously," Shaker said."I'm hoping we'll see a wearable device on the market within the next five years."