The handheld device emits high-intensity ultrasound and focuses the rays at a desired location. Recent experiments used the tool to seal injured lungs.  
 
..."The results are really impressive," Vaezy said. He cautions 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 investigated 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. Researchers are exploring the use of high-intensity focused ultrasound - with beams tens of thousands of times more powerful than used in imaging - for applications ranging from numbing pain to destroying cancerous tissue.