Soon punctured lungs could be treated by a medical device right out of Star Trek.

Engineers at the University of Washington are working with Harborview Medical Centre doctors to create new emergency treatments right out of Star Trek: a tricorder type device using high-intensity focused ultrasound rays.

The researchers have published their first experiment using ultrasound to seal punctured lungs, and results have shown that punctures on the lung's surface, where injuries usually occur, heal with ultrasound therapy.

"No one has ever looked at treating lungs with ultrasound. The results are really impressive," said Shahram Vaezy, a UW associate professor of bioengineering. However, Vaezy cautioned that this is still in the early stages and the technique is not yet being tested on humans.

High-intensity focused ultrasound is now being examined for a number of different treatments. It promises "bloodless surgery" with no scalpels or sutures in sight. Doctors would pass a sensor over the patient and use invisible rays to heal the wound.

In this case, lenses focus the high-intensity ultrasound beams at a particular spot inside the body on the patient's lungs. Focusing the ultrasound beams, in a process similar to focusing sunlight with a magnifying glass, creates a tiny but extremely hot spot about the size and shape of a grain of rice. The rays heat the blood cells until they form a seal. Meanwhile the tissue between the device and the spot being treated does not get hot, as it would with a laser beam.

"You can penetrate deep into the body and deliver the energy to the bleeding very accurately," Vaezy said.

Recent tests on pigs' lungs showed that high-intensity ultrasound sealed the leaks in one or two minutes. More than 95 percent of the 70 incisions were stable after two minutes of treatment. The findings suggest that ultrasound might replace what is now a painful, invasive procedure.

The new research shows that in these difficult cases, high-intensity focused ultrasound applied from outside could stop bleeding and air leaks. Vaezy and colleagues in the Centre for Industrial and Medical Ultrasound in the UW's Applied Physics Laboratory have been developing ultrasound for surgery for more than a decade, concentrating on frequencies in the 1000 to 10,000 hertz (cycles per second).

The device producing the ultrasound rays, about the size of a golf ball, is inserted into a handle that doctors use to scan the outside of the body. Previous experiments used the tool to seal blood vessels and stop bleeding in the spleen. Someday, researchers predict, this tool might be used for image-guided therapy.

"Doctors will scan the body from the outside, recognize where the injury is, focus the beam on the injury and use the beams to seal the wound," said co-author Gregory Jurkovich, chief of trauma at Harborview Medical Center in Seattle and a UW professor of surgery.

"It would be non-invasive and it would stop the bleeding from the outside. When it happens, that's going to revolutionise how we would care for some of these injuries," he added.