Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Time-reversal acoustics research promises medical breakthroughs

08.04.2004


Scientists have not yet found a way to actually make time run backward, but in the cutting-edge world of recent acoustics research, they have shown a way to make sound waves run backward in a kind of ultra-focused reverse echo. By the technology known as time-reversal acoustics, sound waves - in exact reverse order from the original sound - echo directly and very precisely back to their source point.



The technology promises a wide array of applications, including medical applications such as ultra-precise medical imaging, diagnostic techniques using ultrasound, incision-free surgical techniques, and even the potential for a method of recharging the batteries of implanted devices like pacemakers without performing surgery.

Dr. Alexander Sutin, an acoustics expert and senior scientist at Stevens Institute of Technology (Hoboken, NJ), is a co-author of six papers to be presented at the Acoustical Society of America’s 75th Anniversary Meeting in May 2004 (New York City). Four of the papers address time-reversal acoustics systems that have potential breakthrough applications in medicine, nondestructive testing and land mine detection.


"Almost all acousticians think that time-reversal acoustics is the hottest topic in acoustics," says Dr. Sutin.

One area of his team’s medical research involves a kind of "virtual finger" that could focus on an area inside the body much more precisely than any other known method. One of the challenges of imaging the human body or targeting tumors or gall stones non-surgically is that the body is not homogenous - tissues, fat and bone vary in density - so most ultrasound signals become distorted. The beauty of time-reversal acoustics (TRA), however, is that the technology works even more precisely in an environment that has lots of ultrasound-distorting obstacles. Difficult environments like the human body actually improve the focusing of ultrasounds to a specific location, sharpening the focus and enhancing precision.

One of the other big advantages of TRA in medical applications is that systems work so rapidly, and refocus so quickly, that movement of the body presents almost no problem.

The TRA systems employ two things: sound (or ultrasound), along with a time-reversal "mirror" that uses an array of transducers. The transducers convert sound waves into electrical signals, then a computer reverses their order, and the transducers transfer electrical signals back into sound and aim the reverse sound waves back in the direction from which they came.

One of Dr. Sutin’s papers addresses how TRA may be used for nonlinear imaging. Such imaging would involve several TRA focusing systems. The interaction of the crossing beams allows three-dimensional, nonlinear acoustic images of an object inside a human body or a material structure.

Dr. Sutin, originally from Russia, conducted experiments in Paris with the worldwide leader in the field of time-reversed acoustics, Dr. Mathias Fink, the technology’s pioneer.

The American TRA system was developed and built at Artann Laboratories, headed by Dr. Armen Sarvazyan, a colleague of Dr. Sutin’s. Experiments on medical applications of TRA were conducted by Dr. Sutin at Artann Labs.

Joint work with scientists from Los-Alamos National Laboratory, Purdue University, University of Colorado, and the Russian Institute of Applied Physics will be presented in two papers, reflecting the progress in the development of nonlinear acoustic methods of crack detection.

Dr.Sutin’s research on time-reversed acoustics is supported by the National Institutes of Health, Los Alamos National Laboratory and NASA.

Another application of a TRA/nonlinear technique would be to use ultrasound to measure the blood pressure inside a certain point or chamber within the heart. To make this work, harmless tiny capsules (ultrasound contract agents) would be introduced in the blood stream. They would react differently during the heart’s different pressure conditions and their reactions would be measured by sound waves aimed from different angles and returned to a time-reversal mirror. Variations in harmonics levels resonating from the capsules would be correlated to ambient pressure. The precision of the TRA system would allow highly accurate focusing in one area of the heart, meanwhile the nonlinear acoustic technique would give a diagnostician information about pressure changes as the heart pumps.

A different application would involve the ability to non-surgically check for cracks in older mechanical heart valves, a valuable tool for warding off difficulties in some heart patients. The detection of internal cracks and flaws in materials is a standard use of nonlinear acoustic technology. This application would simply employ it inside the human body with the benefit of TRA focusing.

Dr.Sutin’s blood pressure measurement research involving time-reversed acoustics has been supported by Stevens Institute of Technology as part of its Technogenesis ® initiatives. (Technogenesis is Stevens’ unique environment for education and research, in which students, faculty, and partners in academia, government and industry jointly nurture new technologies and companies from laboratory innovation to marketplace implementation.)

Dr. Sutin’s senior scientist position is within Stevens’ Davidson Laboratory, part of the Charles V. Schaefer School of Engineering with special emphases on ocean engineering and acoustical research.

Established in 1870, Stevens Institute of Technology offers baccalaureate, master’s and doctoral degrees in engineering, science, computer science, management and technology management, as well as a baccalaureate in the humanities and liberal arts and in business and technology. The university, located directly across the Hudson River from New York City, has a total enrollment of about 1,700 undergraduates and 2,600 graduate students. Additional information may be obtained from its web page at www.stevens.edu .

Cass Bruton-Ward | Stevens News Service
Further information:
http://www.stevens.edu

More articles from Physics and Astronomy:

nachricht New NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center

nachricht Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>