Intelligent sensing technology developed by MIT can measure our vital stats—without needing a single wearable device.
The newest generation of IoT sensing technology allows us to build intelligent environments that can monitor and react to our daily activities, including locking our doors, turning appliances off and on remotely, and adapting our heating and cooling systems. Some environments and sensors can now respond to our gestures and movements, allowing us to monitor everything from a dog who is sitting at home alone to keeping a watchful eye on our elderly population.
Smart homes may soon be able to dive deeper into our health status, as researchers at MIT have developed a wireless sensing technology that passively monitors breathing and heart rate—all without touching the body. The system, called Vital-Radio, does not require any wearable technology. Instead, it transmits a wireless signal and tracks how the signal is altered by motion in the environment, like the rising and falling of your chest or skin vibrations caused by your heartbeat.
MIT recently shared details about how this technology works. Vital-Radio transmits a low-power wireless signal and measures the time it takes its signal to travel to the human body and reﬂect back to its antennas. Knowing that wireless signals travel at the speed of light, the product can use the reﬂection time to compute the distance from the device to the human body. This distance varies slightly and periodically as the user inhales and exhales and her heart beats. Vital-Radio captures these minute changes in distance and uses them to extract the user’s vital signs.
Photo credit: MIT.edu
When a person inhales, their chest expands and moves outward (closer to the antenna), reducing the reflection time, or the time it takes the signal to reflect back to the device. When a person exhales, the chest contracts inward and moves away from the antenna, increasing the reflection time.
According to Sherbit, the MIT scientists said that they can measure breathing and heart rate with a median accuracy of 99 percent, with sensors that can see through walls from eight meters away.
The golden ticket for Vital-Radio is its no-wearable-required status. The current generation of wearable vital sensors such as nasal probes and chest bands are still considered too difficult to use on a regular basis and are physically intrusive. And with most vital sensors now on the market, the more comfortable the technology is for the user to wear, the less accurate are its measurements.
Waiting with Bated Breath for Better Tech
While this type of wireless monitoring isn’t entirely new, the Vital-Radio overcomes some of the past problems. For instance, wireless monitors of this kind used in other applications have had difficulty distinguishing between moving objects and can become confused when the monitor senses multiple people in the environment. MIT reports that Vital-Radio’s innovation is “its ability to localize a signal and isolate an individual in the environment, eliminating sources of interference, including noise or extraneous movements that mask the minute variations representing breathing and heart rate.”
The researchers at MIT outlined several potential uses for Vital-Radio technology, including monitoring patients in an elderly care home or assisted living center which may not have on-call nurses to check vitals on every patient every day. Another use is to automate home systems, adapting lighting or temperature based on inferences about a person’s mood from heartrate and breathing.
They also noted that Vital-Radio could be useful in an exercise room or gym to monitor heart rate recovery, which is a measure of how fast a person’s heart rate decreases after exercising. Heart rate recovery is an important metric for determining how healthy a person’s heart is and is also a predictor of mortality. Vital-Radio could contribute to a smart home inhabitants’ well-being by accurately measuring her heart rate after exercise.