Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Duke engineers developing ultrasound devices combining 3-D imaging with therapeutic heating

07.11.2005


Duke University engineers are developing technology that may enable physicians to someday use high frequency ultrasound waves both to visualize the heart’s interior in three dimensions and then selectively destroy heart tissue with heat to correct arrhythmias.



"No one else has developed a way for ultrasound to combine therapy and imaging in a catheter, let alone 3-D imaging," said Stephen Smith, the biomedical engineering professor who heads the project at Duke’s Pratt School of Engineering.

Smith’s group described work that developed initial laboratory prototypes in two research papers published in October 2005 in the journal "IEEE Transactions on Ultrasonics, Ferroelectronics and Frequency Control" and the journal "Ultrasonic Imaging."


In an interview, he said his group’s technique may improve on doctors’ most widely used method for destroying -- or "ablating" -- aberrant tissue that makes hearts beat irregularly. That current technique employs radio waves emitted from the end of an electrode probe that touches and excessively heats tissue selected for destruction.

After threading that internal probe into the heart through arteries, physicians must now rely on fluoroscopic imaging -- X-ray movies -- to help point the device. "However, a fluoroscope cannot image soft tissue at all," Smith said. "So the heart is just a fuzzy background." Under those circumstances, fluoroscopy can provide physicians "only a very gross guidance," he added.

Duke biomedical engineers previously pioneered techniques rendering the kind of soft tissue internal images that enable fetuses to be seen in the womb. They have also pioneered the use of ultrasound to create 3-D images of the heart and other organs.

During the past five years other researchers have followed up by developing tiny internal ultrasound imaging probes than can provide physicians better visual guidance than X-rays for internal surgery, Smith said. But those previous tiny probes acquire only two-dimensional images, which still have shortcomings for pinpoint tissue ablation, he said.

Meanwhile, other researchers have separately crafted probes using stronger ultrasound waves to heat internal tissues for ablation rather than for imaging. But combining ablation with 3-D imaging in one device is new, he said.

"The nice thing about ultrasound ablation is that you don’t have to touch the tissue," Smith said. "The sound waves propagate through the blood and can ablate the tissue from a distance of a centimeter or two."

His group’s new work builds on its previous success at miniaturizing ultrasound 3-D imaging probes to a dime-sized array of hundreds of individual ultrasound sound sending and receiving elements, called transducers. Such probes are small enough to insert inside the esophagus to render images of the whole heart.

Smith said his team has now built dual-function imaging-plus-ablation ultrasound probes as small as three millimeters -- less than half the size of a dime. "We started using very tiny cables, fitting as many as two hundred into a three millimeter catheter," he said. "This advance in cable technology has allowed us to incorporate both 3-D imaging and ablation in the same catheter.

"The ability to build these tiny matrix arrays is a technology that we’ve developed at Duke for the past decade and now the ultrasound community is following in our footsteps."

In another paper prepared for an October 2003 IEEE ultrasonics symposium, Smith and his former graduate student Kenneth Gentry -- now a postdoctoral researcher at the University of Wisconsin -- described using a prototype device to first image and then raise the temperature of a tissue-mimicking rubber by 25 degrees Fahrenheit. That temperature increase was enough to ablate real tissue, he said. According to that earlier symposium paper, the prototype was also ablation tested on a piece of beef muscle and imaging tested within a fixed sheep heart.

According to Smith, the ablation beam emerging from the same 112-transducer array was 50 times more energetic than the imaging beam. "So far, we’ve been taking turns at imaging for an instant and than ablating in the next instant," he said.

He acknowledged that further miniaturization and other design work will be necessary to build a device small enough to be inserted through vascular pathways into real hearts for visualization and ablation trials.

"We’ve had the design intuition that allows us to do and describe some preliminary experiments," he said. "But we have not yet made a practical device that could even be used in a live animal."

Monte Basgall | EurekAlert!
Further information:
http://www.duke.edu

More articles from Agricultural and Forestry Science:

nachricht Alkaline soil, sensible sensor
03.08.2017 | American Society of Agronomy

nachricht New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>