A team of doctors in Glasgow, Scotland, have begun using ultrasound to help heal patients’ broken bones, claiming the technique can reduce recovery time by up to 40 percent with especially bad fractures. Developed in the 1950s by physicians in the same city, ultrasound is widely used in sonograms to produce images of developing fetuses. Sonograms are made by emitting sound waves into the body and recording the reflected patterns. To heal fractures, sound is emitted at a slightly different frequency and stimulates the development and activity of osteoblasts, which lay down new bone.
We mentioned on Monday that Bill Gates was giving $300,000 to a geoengineering scheme that would shoot seawater skyward to seed clouds. But the billionaire doesn’t just wanted to save the planet and stop the AIDS crisis—he would also like to improve your sex life.
The Bill & Melinda Gates Foundation funded 78 promising but offbeat projects this week, one of those gifts being $100,000 to James Tsuruta and Paul Dayton of the University of North Carolina to pursue their idea of using ultrasound as a temporary and reversible male contraceptive.
Ultrasound produces a mild heating that appears to disable sperm cells and deplete the supply of stem cells that are required to replenish sperm reserves in the testes. Post-treatment images of the rat testes showed the tubules inside the testes completely lacking in sperm with almost no immature stem cells [The Times].
Doctors already use concentrated sound waves to see through solid tissue and take a look inside the body, as with ultrasound scans. But in this week’s Proceedings of the National Academy of Sciences, Caltech scientists say they’ve developed a metamaterial that focuses sound to such a high concentration that it could go on the offensive, targeting cancers or kidney stones while leaving the surrounding tissues alone. Oh, and one other thing: The military could use it to make weapons.
“The beauty of this system is that it’s just a bunch of ball bearings that we control with weights,” said Chiara Daraio [Discovery News], a member of the research team. Caltech’s acoustic lens relies on the same principle as Newton’s cradle—that toy your high school science teacher probably kept on his or her desk with metal balls on strings that demonstrated the conservation of energy. In this design, 21 parallel chains each contain 21 bearings. When the team strikes one end, it starts a compression wave that carries through the system. But instead of having the last ball swing out like a pendulum and bring the momentum back into the system, like the toy does, the acoustic lens focuses all the energy at the end of the system onto one spot, just a few inches away from the metamaterial.
A biotech company is developing an “ultrasonic tourniquet” that could be used to quickly staunch bleeding for soldiers in the battlefield. The company, Siemans Healthcare, announced that it has won a contract with the U.S. Defense Advanced Research Projects Agency (DARPA), which hopes to have a prototype of the device in hand within 18 months.
The hope is that the device, known as the Deep Bleeder Acoustic Coagulation cuff (or DBAC), will be able to non-invasively clot blood vessels and stop internal bleeding from combat limb injuries – the leading preventable cause of death of soldiers in action. Longer term, Siemens believes the technology will also find applications in civilian care [Medical Physics Web].