When Wi-Fi first became popular I thought it was a real life-saver. I never knew it might actually SAVE A LIFE some day. 

From the article:

Wi-Fi routers continuously broadcast radio frequencies that your phones, tablets and computers pick up and use to get you online. As the invisible frequencies travel, they bounce off or pass through everything around them — the walls, the furniture and even you. Your movements, even breathing, slightly alter the signal’s path from the router to your device. 

Those interactions don’t interrupt your internet connection, but they could signal when someone is in trouble. NIST has developed a deep learning algorithm, called BreatheSmart, that can analyze those minuscule changes to help determine whether someone in the room is struggling to breathe. And it can do so with already available Wi-Fi routers and devices. This work was recently published in IEEE Access.