Within the needle are two optical fibers. One generates ultrasonic pulses by delivering brief flashes of light and the other detects the light that's reflected by the tissues in the body. "The whole process happens extremely quickly, giving an unprecedented real-time view of soft tissue," Richard Colchester, an author of the study, said in a statement. "Using inexpensive optical fibres, we have been able to achieve high resolution imaging using needle tips under 1 mm," said co-author Adrien Desjardins.

So far, the researchers have tested the ultrasound needle during heart surgery in pigs and they hope to test it out in other clinical applications that use minimally invasive techniques as well. They're also working towards using the technology in humans. You can check out the video below for more info on the needle.

Image: Finlay et al. / Light: Science & Applications