mmWave radar uses radio waves to sense motion, distance, and changes in position. Unlike a camera, it does not need to create a normal video image of the room.
What the sensor can observe
Depending on the hardware and software, a radar sensor can estimate whether someone is moving, standing, sitting, or remaining close to the floor for an unusual period of time.
Why it is interesting for elder care
The technology can work in darkness and can be designed for rooms where cameras feel intrusive. That makes it particularly relevant for privacy-first home monitoring.
The hard part is software
Detecting a real fall reliably is harder than simply detecting motion. A useful product needs to distinguish everyday actions from unusual events while keeping false alarms low.