What does predicting heart attacks have in common with the ability to communicate effectively in extremely loud environments? The answer may well involve a new smart sensor developed by researchers from the University of Colorado Boulder and Northwestern University.
What they have created is a small, wearable acoustic sensor — around the size of a Band-Aid — that measures vibrations in the human body. In doing so, it’s capable of monitoring the health of a person’s heart, as well as interpreting spoken words, depending upon where it is placed.
“Many kind of skin-mounted electronics have been demonstrated by integrating electrophysiological sensors — ECG [electrocardiogram] and EMG sensors, temperature sensors, strain sensors, and many others,” Jae-Woong Jeong, a professor in Boulder’s Electrical, Computer and Energy Engineering Department, told Digital Trends. “What has not been explored before was sensing of acoustic signals from the body. Our work was about the development and investigation of wearable acoustic sensors.”
Weighing less than 1/100th of an ounce, the skin-mounted acoustic sensors can capture physiological sound through skin vibrations.
“By mounting it on the chest, we can measure heart sounds that give a lot of information for heart function and heart failure,” Jeong continued.
Although there are existing wearable electronic devices capable of measuring the rate and rhythm of heartbeats using ECG technology, this method has limitations in diagnosing heart failure. For instance, structural defects in heart valves don’t appear in ECG signals, although they can be picked up using acoustic signals.
The sensor can also be placed on a wearer’s throat, where it can measure vocal cord vibration for speech recognition — and possibly be used to provide improved communication for people with speech disorders. “Potentially, it can provide noiseless voice communication, even in a very noisy environment such as a battlefield because it captures acoustic signals directly through skin vibration,” Jeong said.
In a test, researchers showed that vocal cord vibrations gathered by the device could control a game of Pac-Man by picking up the unique vocal vibration signals for the words “up,” “down,” “left” and “right.”
As exciting as this technology is, Jeong noted that it is not quite ready for prime time just yet.
“The current version of our acoustic sensor is a wired device,” he said. “We had to connect a thin cable to the device for testing. In the future, we will integrate wireless capability for data transfer and control to make it more practical.”