Burlap writes to tell us the MIT Technology Review is reporting on a new DARPA venture to create an "ultrasonic tourniquet
" to help stem bleeding on injuries sustained in battle. The project plans to commit $51 million over the course of 4 years. From the article: "[I]t aims to create a cuff-like device that wraps around a wounded limb. Rather than applying pressure to the wound to stem the flow of blood, the device would use focused beams of ultrasound (sound waves above the audible frequencies) to non-invasively clot vessels no matter how deep they are."