Researchers at the University of California, Berkeley and UC Davis are developing Chirp, a computer chip that uses ultrasound waves to detect a wide range of gestures in three dimensions, and could be implanted in wearable devices. The researchers say Chirp eventually could be used in devices ranging from helmet cameras to smart watches. Chirp relies on sonar via an array of ultrasound transducers that send ultrasonic pulses outward in a hemisphere, echoing off objects in their path. The echoes can be used to detect a range of hand gestures in three dimensions within a distance of about a meter. Berkeley's Richard Przybyla says Chirp's basic set of gesture commands could be programmed into Chirp-enabled devices. Since the system uses sound, which travels considerably slower than light, it can use low-speed electronics for sensing, which significantly decreases the system's overall power consumption, enabling it to run off a watch battery continuously for up to 30 hours, Przybyla says. In the future, the researchers hope to develop the technology to be able to recognize individual finger movements, instead of just hand gestures.