Today’s health sensors (which monitor breathing, heartbeats, steps, etc.) require their users to wear them on their bodies. In contrast, our technologies can monitor human health without requiring the user to wear any device on his/her body. To do so, MIT Signal Kinetics research group captured and analyzed wireless signals reflected off the human body; then use these reflected signals to extract breathing and heartbeats without any physical contact with the human body. Team is currently exploring techniques to remotely sense additional health metrics like blood pressure, oxygen saturation, and glucose levels. Monitoring these health metrics can render ICU (intensive care unit) vital sign monitors completely noninvasive and enable continuous monitoring of diabetes patients.
The evolution of ubiquitous sensing technologies has led to intelligent environments that can monitor and react to our daily activities, such as adapting our heating and cooling systems, responding to our gestures, and monitoring our elderly. MIT Signal Kinetics research group is trying to ask whether it is possible for smart environments to monitor our vital signs remotely, without instrumenting our bodies.
Team introduced Vital-Radio, a wireless sensing technology that monitors breathing and heart rate without body contact. Vital-Radio exploits the fact that wireless signals are affected by motion in the environment, including chest movements due to inhaling and exhaling and skin vibrations due to heartbeats. We describe the operation of Vital-Radio and demonstrate through a user study that it can track users’ breathing and heart rates with a median accuracy of 99%, even when users are 8 meters away from the device, or in a different room.
Furthermore, it can monitor the vital signs of multiple people simultaneously. We envision that Vital-Radio can enable smart homes that monitor people’s vital signs without body instrumentation, and actively contribute to their inhabitants’ well-being.
However, natural environments have a large number of re- flectors, such as walls and furniture as well as multiple users whose bodies all reflect the wireless signal.
To address these issues, Vital-Radio’s operation consists of three steps: 1. Isolate reflections from different users and eliminate reflections off furniture and static objects. 2. For each user, identify the signal variations that are due to breathing and heartbeats, and separate them from variations due to body or limb motion. 3. Analyze signal variations to extract breathing and heart rates.
Team envision that Vital-Radio can be deployed in a smart home to monitor its inhabitants’ breathing and heart rates, without body instrumentation. The device can monitor multiple users’ vital signs simultaneously, even if some of them are occluded from the device by a wall or a piece of furniture.
After Vital-Radio isolates reflections from different moving users into separate buckets, it proceeds by analyzing each of these buckets to identify breathing and heart rate.