Shahram Vaezy, Ph.D., and colleagues in Dept. of Bioengineering at the University of Washington applied high intensity ultrasound to damaged lungs to try to close air leaks, and found impressive clinical results:
… the high-intensity ultrasound beams focus on 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 tissue and 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, according to results published this summer in the Journal of Trauma.
The findings suggest that ultrasound might replace what is now a painful, invasive procedure. Lung injuries are relatively common because the chest is a big surface that’s often exposed to crushing or puncture wounds, said co-author Gregory Jurkovich, chief of trauma at Harborview Medical Center in Seattle and a UW professor of surgery. A busy trauma room like Harborview’s, he said, admits about two patients with bleeding lungs per day…
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 UW’s Applied Physics Laboratory have been developing ultrasound for surgery for more than a decade, concentrating on frequencies in the 1 million to 10 million hertz (cycles per second) range. 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 liver, spleen and kidneys.
Someday, Jurkovich predicts, this tool might be used for image-guided therapy.
Dr. Vaezy has kindly provided us with the following pictures of his research (subtitles underneath):
Subtitles: The HIFU device being applied to a liver incision for hemostasis treatment; Left: The HIFU device being applied to a liver incision for hemostasis treatment; Right: IR video capture, showing high temperature regions at the focal region; Various HIFU devices.
Press release: Star Trek medical device uses ultrasound to seal punctured lungs …
HIFU Flashbacks: ExAblate 2000 ; High Intensity Focused Ultrasound (HIFU) for Body Scuplting; High Intensity Focused Ultrasound for AFib; Noninvasive Palliation of Pain of Bone Mets; Ultrasonic Tourniquet (with HI-FU Grip); Long Term Effectiveness of Ultrasound on Uterine Fibroids
(hat tip: MTB Europe)
