Neurologists have built an ultrasound device which uses focused sound waves to destroy stroke-causing blood clots in brains. The procedure is non-invasive—requiring no drugs or surgery—and is already being tested on patients.

The machine and procedure allows doctors to "surround the head with an array of transducers that can focus ultrasound beams on a single spot in the brain without damaging the skull." This means that diseased tissue could be destroyed without any collateral damage or risky surgery. [Technology Review via Pop Sci]