Laser can detect decompression sickness before symptoms appear

November 16, 2007, Houston, TX--It may not rank among the top 10 causes of death, but decompression sickness can be fatal. Instead of waiting for symptoms to appear, a University of Houston professor is developing a laser-based system that can diagnose the sickness in a matter of seconds.

Kirill Larin, assistant professor of biomedical engineering and mechanical engineering, is using a $400,000 grant from the U.S. Navy to develop the first optical non-invasive tool to test those most likely to suffer from decompression sickness, such as scuba divers, submariners and airplane pilots. Decompression sickness affects those who experience sudden, drastic changes in the air or water pressure surrounding their bodies. It can cause anything from joint pain--known as the bends--to seizure, stroke, coma and, in the most extreme cases, death.

Larin's optical device can locate the presence of nitrogen gas--or microbubbles--in blood and tissues, which can restrict the flow of blood throughout the body and cause damage. Larin is developing the tool, which works much like an ultrasound machine, with Dr. Bruce Butler of the UT Health Science Center in Houston. Instead of getting readings using sound waves, however, Larin's system uses light waves in the form of lasers that bounce back when they encounter resistance, thereby providing a high-resolution image.

An early version of the tool has been able to locate microbubbles as small as 6 µm. Most microbubbles are between 5 and 15 µm, about the size of a red blood cell.

For more information, visit www.uh.edu.