Ultrasound Chip Could Bring Gesture Recognition to Smart Watches

By Wesley Fenlon

The chip, called Chirp, can recognize hand gestures from about a meter away, and consumes little power.

The field of 3D gesture recognition--waving hands in the air instead of swiping fingers around on a touchscreen--has seen some promising technology, but few useful implementations. Microsoft's Kinect is the big name, and its movement recognition still struggles to create good gaming experiences. Another piece of technology we covered a couple years ago, the Geremin, used a small electric field to allow drivers to gesture with a finger raised from the steering wheel. Ideally, this could be less distracting than looking at a car dashboard and fiddling with a touchscreen.

Touchscreens are intuitive, but they're not suited to every type of user interface. A bit like the Geremin, a new gesture recognition chip called Chirp uses ultrasound to pick up 3D gestures. Chirp also aims to fulfill a similar purpose: Embedded in a smartwatch, the chip would let you perform gestures in the air, instead of on a tiny smartwatch screen. When a screen is barely larger than your finger, it's difficult to perform a variety of gestures. Chirp could solve that problem.

Technology Review writes: "Chirp uses sonar via an array of ultrasound transducers—small acoustic resonators—that send ultrasonic pulses outward in a hemisphere, echoing off any objects in their path (your palm, for instance). Those echoes come back to the transducers, and the elapsed time is measured by a connected electronic chip. When using a two-dimensional array of transducers, the time measurements can be used to detect a range of hand gestures in three dimensions within a distance of about a meter."

Chirp's developers are still working to improve its three dimensional tracking ability. Technology Review noted that testing out its side-to-side and forward-and-back movement, "It was noticeably easier to control on my first try than some other kinds of gesture-recognition technologies I’ve tried, and didn’t seem to require any calibration to sense most of my movements accurately."

Currently, Chirp only tracks hand gestures, not individual finger movements, but that may be the next step. It's also power efficient enough to run off a small watch battery for 30 hours. By the time smartwatches kick off in full force, maybe we'll see embedded gesture recognition chips like Chirp make them considerably more interactive.