A team from MIT's Computer Science and Artificial Intelligence created a new device called RF-Capture - which can capture and form human figures through walls by analyzing the reflections from the transmitted wireless signals. These wireless signals can go through walls, and as they reflect off the moving human body, RF-Capture takes a snapshot. An algorithm then identifies the body parts and creates a human silhouette. The device can "determine subtle differences in body shapes" at 90% accuracy, and it could even distinguish one person from another. It can also determine an individual's heart rate and breathing patterns. This software is an extension of an existing study, which uses radio frequency technology to detect motion through a wall.
Here's a feature video for RF-Capture:
MIT researchers say that there aren't any real-life applications for the technology just yet, but they think that it could be used to track an elderly person's movements if they are living alone to help ensure their safety. They also see the possibility of applying it in smart homes, specifically in controlling appliances through gestures. The researchers are aware that RF-Capture could be used in spying, but they assure the public that this won't be an issue and that they've already designing blockers that will only allow a person to be tracked by their own device.