Miniature wearable acoustic sensor recognises speech
Image credit: Northwestern University, University of Colorado Boulder
A miniature acoustic sensor that can be worn on the body as a patch can recognise human speech.
The gadget, developed by US researchers from the University of Colorado Boulder and Northwestern University, measures vibrations propagating through the body, which could be useful for monitoring of heartbeat, lung function or the activity of the gastrointestinal tract. Similarly, the technology can register vibrations of the vocal chords, which could be used to recognise speech.
The team envisions the stretchable sensor, which weighs just 30 grams, could be used by soldiers or civilians to control drones and robots or to aid people with hearing impairments.
“It is very comfortable and convenient - you can think of it as a tiny, wearable stethoscope,” said CU Boulder Assistant Professor Jae-Woong Jeong, one of the authors of the study published in the journal Scientific Advances.
In their experiments, the researchers used the device attached the user’s throat to control a Pac-Man game. The device was able to successfully transmit commands for ‘up’, ‘down’, ‘left’ and ‘right’, as the player was pronouncing them.
The sensor can be also fitted with electrodes to record electrical activity of the heart and muscles.
“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.
In cooperation with the University Arizona, the researchers measured cardiac acoustic responses and ECG activity - including the detection of heart murmurs - in a group of elderly volunteers at a private medical clinic in Tucson, Arizona. The device was also able detect the acoustical signals of blood clots in a related lab experiment.
“While other skin electronics devices have been developed by researchers, what has not been demonstrated before is the mechanical-acoustic coupling of our device to the body through the skin,” Jeong said. “Our goal is to make this device practical enough to use in our daily lives.”
The sensor is covered in a flexible polymer material that can stretch and flex following the skin without sustaining any damage.
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.