Volvo has developed a new interior radar feature designed to be accurate and sensitive enough to detect the tiniest movements at sub-millimetre scale, such as those of a sleeping toddler. It’s the first such feature to cover the entire interior of the car, including the boot (trunk).

The new radar will be included in the upcoming BEV EX90 SUV designed to prevent children being accidentally left in cars.

US government statistics show that since 1998 900 children in the US have died after being left in hot cars. Heartbreakingly, a majority of hot car deaths occur because someone forgot that their child was in the car at the time.

The system will be standard in the EX90 where regulation allows and added to other models later.

Sensors integrated in the overhead console, roof-mounted reading lamps and the boot can detect sub-millimetre movement in the entire interior.

To cover as much of the cabin as possible and sense whether a child or pet has been left in the car, radars are spaced throughout the cabin.

Engineers determined the best time to signal the potential presence of family members left inside the car is during an attempt to lock the car.

Each time the car is locked, the interior radar system is activated and determines whether it is empty of people or pets, before it allows the car locking.

If an occupant is detected, the car will remain unlocked and display a reminder to check the cabin for occupants on the centre console screen.

The climate system can remain on if people or animals are detected in the cabin, to improve comfort. This can also help lower the risk of hypothermia or heatstroke.

The interior radar system will come as standard in all countries where the 60GHz frequency used by the system is approved for automotive use and remain working as long as the high voltage battery has enough charge.

Toyota is working on concept technology to help detect occupants in cars who have been left behind.

Four years ago, Nissan’s US unit introduced a Rear Door Alert system which can help remind drivers to check the rear seat by using a series of distinctive honks as the driver is walking away from the vehicle.