The Second Coming of Ultrasound
Researchers are fitting people’s heads with ultrasound-emitting helmets to treat tremors and Alzheimer’s. They’re using it to remotely activate cancer-fighting immune cells. Startups are designing swallowable capsules and ultrasonically vibrating enemas to shoot drugs into the bloodstream. One company is even using the shockwaves to heal wounds
Ultrasound, as you may have figured out by now, runs on piezoelectricity. Applying voltage to a piezoelectric crystal makes it vibrate, sending out a sound wave. When the echo that bounces back is converted into electrical signals, you get an image of, say, a fetus, or a submarine.
So how did this 100-year-old technology learn some new tricks? With the help of modern-day medical imaging, and lots and lots of bubbles.
Bubbles are gas-filled microbubbles that technicians use to bump up contrast in grainy ultrasound images. Passing ultrasonic waves compress the bubbles’ gas cores, resulting in a stronger echo that pops out against tissue.
