Navigation Links
Super-fine sound beam could one day be an invisible scalpel
Date:12/19/2012

ANN ARBORA carbon-nanotube-coated lens that converts light to sound can focus high-pressure sound waves to finer points than ever before. The University of Michigan engineering researchers who developed the new therapeutic ultrasound approach say it could lead to an invisible knife for noninvasive surgery.

Today's ultrasound technology enables far more than glimpses into the womb. Doctors routinely use focused sound waves to blast apart kidney stones and prostate tumors, for example. The tools work primarily by focusing sound waves tightly enough to generate heat, says Jay Guo, a professor of electrical engineering and computer science, mechanical engineering, and macromolecular science and engineering. Guo is a co-author of a paper on the new technique published in the current issue of Nature's journal Scientific Reports.

The beams that today's technology produces can be unwieldy, says Hyoung Won Baac, a research fellow at Harvard Medical School who worked on this project as a doctoral student in Guo's lab.

"A major drawback of current strongly focused ultrasound technology is a bulky focal spot, which is on the order of several millimeters," Baac said. "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 team was able to concentrate high-amplitude sound waves to a speck just 75 by 400 micrometers (a micrometer is one-thousandth of a millimeter). Their beam can blast and cut with pressure, rather than heat. Guo speculates that it might be able to operate painlessly because its beam is so finely focused it could avoid nerve fibers. The device hasn't been tested in animals or humans yet, though.

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

To achieve this superfine beam, Guo's team took an optoacoustic approach that converts light from a pulsed laser to high-amplitude sound waves through a specially designed lens. The general technique has been around since Thomas Edison's time. It has advanced over the centuries, but for medical applications today, the process doesn't normally generate a sound signal strong enough to be useful.

The U-M researchers' system is unique because it performs three functions: it converts the light to sound, focuses it to a tiny spot and amplifies the sound waves. To achieve the amplification, the researchers coated their lens with a layer of carbon nanotubes and a layer of a rubbery material called polydimethylsiloxane. The carbon nanotube layer absorbs the light and generates heat from it. Then the rubbery layer, which expands when exposed to heat, drastically boosts the signal by the rapid thermal expansion.

The resulting sound waves are 10,000 times higher frequency than humans can hear. They work in tissues by creating shockwaves and microbubbles that exert pressure toward the target, which Guo envisions could be tiny cancerous tumors, artery-clogging plaques or single cells to deliver drugs. The technique might also have applications in cosmetic surgery.

In experiments, the researchers demonstrated micro ultrasonic surgery, accurately detaching a single ovarian cancer cell and blasting a hole less than 150 micrometers in an artificial kidney stone in less than a minute.

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


'/>"/>

Contact: Nicole Casal Moore
ncmoore@umich.edu
734-647-7087
University of Michigan
Source:Eurekalert

Related medicine news :

1. Study examines benefit of follow-up CT when abdominal ultrasound inconclusive
2. Breast cancer patients with positive ultrasound guided axillary node biopsy need dissection
3. Automated breast ultrasound dramatically reduces physician interpretation time
4. Screening for breast cancer without X-rays: Lasers and sound merge in promising diagnostic technique
5. Contrast-enhanced ultrasound monitors aortic aneurysm treatment
6. Huge Rise in CT, MRI, Ultrasound Scan Use: Study
7. AIUM and AUA guideline development leads to practice accreditation for urologic ultrasound
8. AMA adopts diagnostic ultrasound utilization and education resolution
9. Rewired visual input to sound-processing part of the brain leads to compromised hearing
10. Scientists use sound waves to levitate liquids, improve pharmaceuticals
11. Sound level around seriously ill patients like a busy road
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/23/2017)... ... June 23, 2017 , ... ... personal financial planning to families and business owners in North Central West Virginia, ... help provide services to differently abled residents in the region. , The Stepping ...
(Date:6/22/2017)... ... 2017 , ... Plastic Surgery Associates is proud to report that founding surgeon, ... research and information firm, Castle Connolly, releases their list of the most notable and ... 3rd time that Dr. Canales has been recognized by Castle Connolly. , ...
(Date:6/22/2017)... ... June 22, 2017 , ... ... grant from the American Heart Association (AHA) to launch a Rheumatic Heart Disease ... the prevention and diagnosis of rheumatic heart disease (RHD) in high-risk, financially disadvantaged ...
(Date:6/22/2017)... ... June 22, 2017 , ... Vighter, a premier provider ... certification for ANSI/ASIS PSC.1-2012. The company’s work in countries throughout Southwest Asia, South ... law has been degraded. The PSC.1 standard was created to protect fundamental freedoms ...
(Date:6/20/2017)... ... June 20, 2017 , ... TwelveStone Health Partners, a premier ... private equity firm, has invested $3.35 million in the company. , “We ... Capital offers the smart money, speed to market and accountability we had been ...
Breaking Medicine News(10 mins):
(Date:6/8/2017)... 2017   Responding to Heath Ledger,s father,s ... of singer Chris Cornell in May, the mental ... a free online psychiatric drug side effects ... about psychotropic drug risks. The father of ... an accidental overdose, has called for tighter rules on prescription ...
(Date:6/7/2017)... June 7, 2017  Novavax, Inc., (Nasdaq: NVAX ... Phase 2 trials of its RSV F protein recombinant nanoparticle ... age have been published in the journal Vaccine ... shared in prior scientific conferences). The Company previously announced ... Novavax is developing the RSV F Vaccine with the goal ...
(Date:6/5/2017)... June 5, 2017 Kohll,s Pharmacy & Homecare is the ... the United States . The Raizer is a simple ... person up to an almost-standing position within a ... by one assistant and does not require any ... that a child can operate it, and lightweight ...
Breaking Medicine Technology: