The best-known byproduct of ultrasound—so named because its frequencies exceed the range of the human ear—is, in fact, not audio but visual: 2D imagery, often of a fetus maturing in the womb. But ultrasound has also found a place in other corners of the medical realm, from assessing blood flow to examining suspicious lumps and diagnosing disease.
Liquid metal may point way to wearable ultrasound devices
