At the December meeting of the Acoustical Society of America (December 3-7), Dr. Shahram Vaezy and his colleagues will present research on using traditional ultrasound to image internal bleeding combined with High-Intensity Focused Ultrasound (HIFU) as an effective method of stopping the bleeding. Vaezy says this research, which is currently being done on animals, has huge implications in human medicine.

Currently, techniques to stop bleeding include manually sealing off the vessel with stitches, using electrical current to generate heat which seals off blood vessels, or using a topical agent. However, all of these technologies require an incision in the skin in order to reach the bleeding. "The key issue," Vaezy says, "is that no current method can stop the bleeding non-invasively."

Vaezy and his colleagues hope to change that. In animal studies, they have been able show that they can use conventional ultrasound to locate internal bleeding, and then use HIFU to stop it - all without a single incision.

HIFU works by generating a lot of heat very quickly (70 degrees C in less than onesecond), causing biological tissues where the ultrasound is focused to shrink and fuse together, stopping bleeding. The HIFU treatment does not require an incision because ultrasound passes through tissue, allowing researchers to focus the cauterizing heat at the point inside the body where they want to stop the bleeding.

In addition to stopping bleeding in blood vessels, Vaezys team has been able to show that HIFU can safely stop bleeding in solid organs like the liver and spleen, where current techniques are not effective. "Imagine," he says, "if we could stop the internal bleeding of a car accident patient at the scene without open
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Contact: Rory Richards
Rrichard@aip.org
301-209-3088
American Institute of Physics
14-Nov-2001