New Band Aid-like device to monitor heart, recognise speech

Researchers have developed a tiny, soft and wearable acoustic sensor that measures vibrations in the human body, allowing them to monitor heart health and recognise spoken words.
The stretchable device captures physiological sound signals from the body, has physical properties well-matched with human skin and can be mounted on nearly any surface of the body, said Jae-Woong Jeong, Assistant Professor at University of Colorado Boulder in the US.
The sensor, which resembles a small Band-Aid, weighs less than one-hundredth of an ounce and can gather continuous physiological data.
"This device has a very low mass density and can be used for cardiovascular monitoring, speech recognition and human-machine interfaces in daily life," said Jeong.

"It is very comfortable and convenient - you can think of it as a tiny, wearable stethoscope," Jeong said.
"The thin, soft, skin-like characteristics of these advanced wearable devices provide unique capabilities for 'listening in' to the intrinsic sounds of vital organs of the body, including the lungs and heart, with important consequences in continuous monitoring of physiological health," said John Rogers from Northwestern University in the US.

The device can pick up mechanical waves that propagate through tissues and fluids in the human body due to natural physiological activity, showing characteristic acoustical signatures of individual events, researchers said.
They include the opening and closing of heart valves, vibrations of the vocal cords and even movements in gastrointestinal tracts.

The sensor can also integrate electrodes that can record electrocardiogram (ECG) signals that measure the electrical activity of the heart as well electromyogram (EMG) signals that measure the electrical activity of muscles at rest and during contraction.
While the sensor was wired to an external data acquisition system for the tests, it can easily be converted into a wireless device, said Jeong.
Such sensors could be of use in remote, noisy places - including battlefields - producing quiet, high-quality cardiology or speech signals that can be read in real time at distant medical facilities.
"Using the data from these sensors, a doctor at a hospital far away from a patient would be able to make a fast, accurate diagnosis," said Jeong.

Vocal cord vibration signals also could be used by the military personnel or civilians to control robots, vehicles or drones.
The speech recognition capabilities of the sensor also have implications for improving communication for people suffering from speech impairments, he said.
The study was published in the journal Science Advances.