Canadian researchers develop radar system for monitoring vital signs

Engineers at the University of Waterloo in Canada have developed a radar-based system for wirelessly monitoring patients’ vital signs.

The mobile-phone sized device records heart and breathing rates using sensitive radar waves that are analysed by algorithms embedded in an onboard digital signal processing unit.

The group developed the system to monitor sleep apnoea patients by detecting subtle chest movements instead of connecting them to equipment in labs via numerous cumbersome wires.

“We take the whole complex process and make it completely wireless,” said George Shaker, an engineering professor at Waterloo. “And instead of a clinic, it could be done in the comfort of your own bed and run daily for continuous monitoring.”

In a study at the University’s Research Institute for Aging, the radar unit was mounted to the ceiling over the bed of more than 50 volunteers as they slept normally in a model long-term care apartment. The technology achieved results over 90 per cent as accurate as standard hard-wired equipment.

“This is the first time radar has been used for heart sensing with this degree of accuracy and in such an uncontrolled environment,” said Mostafa Alizadeh, a research associate who led the study. “Our subjects slept unobstructed, in any position, for up to eight hours.”

As well as sleep apnoea, which involves breathing that repeatedly stops and starts, the system can monitor conditions such as periodic limb movement disorder, restless leg syndrome and seizures.

The team is also exploring use of the technology to monitor activity levels and falls by residents of long-term care homes, and in hospitals for routine monitoring of heart and breathing rates of all kinds of patients.

A paper on their work, Remote monitoring of human vital signs using mm-wave FMCW radar, appears in the journal IEEE Access.