Motion sensors have been in development and use for many decades now. Home alarm system rely upon them to detect general movement, Microsoft uses an advanced sensor for detecting body movements through Kinect, and there’s currently research being carried out to detect the movement of individual fingers. If you want to be more precise than that, there’s always the option to use lots of sensors, too.

Telecommunications company OKI is going one better than that though, and has created a new sensor that is so sensitive it can tell if a person is breathing or not. It can do this without being exposed, meaning you can place multiple objects in between the sensor and the subject without it causing any degradation in accuracy.

The reason it can achieve this is because it relies on microwaves in the 10.5GHz and 24GHz frequency bands. It “sees” objects by using radio waves and the Doppler effect to detect movement very precisely and to the point where the breathing movements of a person’s chest are picked up.

OKI couldn’t just use a microwave sensor, though. As they are so sensitive they pick up all movement in an area including the heat coming off a radiator and the air movement of an air conditioning system. The sensor therefore had to be combined with a system whereby human movement could be picked out from a busy scene. This was achieved with the help of the Chuo University Statistical Data Analysis Group, who implemented a that allowed the sensor to pick out human movement alone.