Coming soon: 'Invisible knife' that lets doctors cut with sound

Coming soon: 'Invisible knife' that lets doctors cut with sound

Summary: New technology uses a carbon nanotube-coated lens to convert light into sound waves that are then focused enough to cut through skin.

TOPICS: Emerging Tech

Scientists have made an 'invisible knife' that uses sound, instead of a sharp edge, to cut, paving the way for non-invasive detailed medical procedures.

The technology concentrates high-amplitude sound waves that are strong enough to cut flesh onto an area of 75 by 400 micrometers (0.075 by 0.4 millimeters), scientists at the University of Michigan announced on Wednesday.

"We believe this could be used as an invisible knife for noninvasive surgery," said Jay Guo, co-author of the paper on the research. "Nothing pokes into your body, just the ultrasound beam. And it is so tightly focused you can disrupt individual cells."

The beam is generated by converting light from a pulsed laser into sound by beaming it through a lens coated with carbon nanotubes and a rubbery material called polydimethylsiloxane.

Light is absorbed by the carbon-nanotube layer and turned into heat; the rubbery material then boosts the resultant signal via rapid thermal expansion; finally, the lens focuses the sound to a very high level.

"A major drawback of current strongly focused ultrasound technology is a bulky focal spot, which is on the order of several millimeters," noted Hyoung Won Baac, a Harvard Medical School research fellow who worked on the technology as a doctoral student in Guo's lab. "A few centimeters is typical. Therefore, it can be difficult to treat tissue objects in a high-precision manner, for targeting delicate vasculature, thin tissue layer and cellular texture. We can enhance the focal accuracy 100-fold."

The generated sound waves are 10,000 times higher than the frequency limit for human hearing.

In early tests the technology was able to detach a single ovarian cancer cell and blast a sub-150 micrometer hole in an artificial kidney stone.

"This work opens a way to probe cells or tissues in much smaller scale," Guo said.

Topic: Emerging Tech

Jack Clark

About Jack Clark

Currently a reporter for ZDNet UK, I previously worked as a technology researcher and reporter for a London-based news agency.

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  • Where is your source?

    I know this is ZDNet but seriously, how do you know this information?
    • UMichigan release

      UMichigan press release, why?
      Jack Clark
      • Paper abstract here

        Also, if you're more technical, here is the abstract from the academic paper, which was pubbed earlier than the UMichigan PR:
        Jack Clark
        • Thank you!

          n t
  • Very cool!

    The turning of technology today is just amazing...
  • A Sonic Lance

    Where have I heard of such a thing before?
    Next thing you know, they will give it the ability to turn small metal objects - say screws.
    • Who Has A Sonic Scalpel?

      Who looks at a scalpel and thinks, "Ooh, this could be a little more sonic"?
    • Yep

      and "The Doctor" already has one, lots of laughs. :)
  • Creeped out

    This is great on a medical level, but yes, I am however fearing the horror stories that filmakers will use if they see this story.
  • DRM

    I presume this won't be locked down to only itunes or an equivalent?
    Little Old Man
  • non-invasive?

    this is only non-invasive if it can focus the cut a fair distance from the tools. Everything said here implies it cuts very close to the instrument and therefore you would need to cut through the tissue surrounding the actual affected area in order to reach it, or use keyhole surgery techniques, both of which are minimally-invasive at best
  • RR

    this is just crazy, but awesome.