Physicists at MIT have modified the way conventional WiFi transmitters work so that they can now be used to see people through walls and even measure their heart rate.
Physicists at MIT have modified the work of conventional WiFi transmitters so that they can now be used to see people through walls and even measure their heart rate, as they talked about on the university website.
According to scientists, they began work on the creation of a similar analogue of "X-ray vision" from comics in 2013, when they managed to create a special algorithm for analyzing the radio signal received by the WiFi receiver, which made it possible to determine that someone was standing or moving behind the wall according to variations in its strength and other parameters.
In their new paper, which will be presented at the SIGGRAPH scientific conference in Kobe, Japan in early November this year, scientists talked about an improved version of this technology, which allows you to literally see who is behind the wall, follow what he writes by hand and even measure the pulse of this person.
The technology works quite simply - a specially modified WiFi transmitter "bombards" the wall. Part of the waves generated by it is reflected from people and objects located behind the wall, and falls back into the signal receiver located nearby. These waves are analyzed using a special algorithm “trained” to recognize silhouettes similar in shape to the human body or individual body parts.
The secret of her success is that the program looks not at one, but at several "frames" at once, which allows her to find a person faster in those cases when each of them contains only a part of the body.
Further improvement of the algorithm allowed scientists to achieve amazing things - for example, the program can now determine the weight and height of a person, which allows it with 90% probability to determine who is behind the wall. Such a skill, scientists suggest, may interest special services and law enforcement agencies.
In addition to this, this algorithm is able to calculate the heart rate and monitor the movements of people behind walls. This feature of the program, according to Fadel Adib and Dina Katabi, the creators of this WiFi-"X-ray imager", allows you to use it to constantly monitor the health of lonely elderly people and automatically call an ambulance if they fall and do not move for a long time.
Promotional video:
And finally, such a thing can be used for entertainment, as a more reliable and more versatile replacement for the Kinect and other similar manipulators that allow you to control the movements of a character in computer games using body movements.