Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Engineers design new optical microprobe to detect subsurface organ abnormalities

17.04.2003


Photonics and ultrasound engineering researchers from Duke University and The George Washington University have collaborated to design an optical scanner miniaturized enough to be inserted into the body, where its light beams could someday detect abnormalities hidden in the walls of the colon, bladder or esophagus.



The experimental device, called an "electrostatic micromachine scanning mirror for optical coherence tomography," is described in an article published in the April 15, 2003, issue of the research journal Optics Letters. Once approved for use in hospitals and clinics, it would provide a new capability for endoscopy procedures.

Using tiny electrically activated artificial muscle fibers to vibrate a gold–covered mirror only about 2 millimeters wide, the prototype device broadcasts a special kind of quasi-laser light that can not only scan internal organ surfaces but also penetrate just beneath the surface.


Key researchers in the miniaturization effort are Jason Zara, an assistant professor of engineering and applied science at George Washington, and Stephen Smith, a professor of biomedical engineering at Duke’s Pratt School of Engineering in Durham, N.C.

"This new device has shown great promise for new diagnostic applications," said Zara, Smith’s former graduate student at Duke who is lead author of the Optics Letter report. Co-authors include Smith; Joseph Izatt, an associate professor of biomedical engineering at Duke’s Pratt School of Engineering; and Izatt’s former graduate student Siavash Yazdanfar and former postdoctoral research associate K. Divakar Rao.

Izatt, who leads biophotonics research activities at the Pratt School’s Fitzpatrick Center for Photonics and Communications Systems, is a leader in the budding optical scanning technology that Zara and Smith have scaled down to fit into catheters.

Zara and Smith designed and fabricated a system that includes a tiny mirror that vibrates up to 2,000 times a second on hinges just 3 millionths of a meter wide. The mirror quivers in response to the action of more than one-half million microscopic energy-storing capacitors arranged in parallel strips of the flexible plastic polyimide.

This arrangement acts like artificial muscle, Smith said. "When a voltage is applied to each of these capacitors, they contract. That pulls the mirror to the right. When the voltage is turned off, the mirror then swings back to the left." As the voltage rapidly switches on and off and the mirror vibrates, a beam of light from a fiberoptic cable is reflected onto a tissue surface in a scanning pattern. This repeat scanning produces optical images of the tissues’ outer layers.

The artificial muscle was made at MCNC, a Research Triangle Park microelectronics and computer research institution founded by the state of North Carolina. Zara and Smith have also founded a startup company, Memscept, Inc., to market the research.

The idea of using light as a deeper probe, called Optical Coherence Tomography (OCT), was pioneered at MIT, where Izatt was a postdoctoral scientist. He continued developing the concept while on the faculty of Case Western Reserve University before coming to Duke.

"The standard endoscope gives a physician an internal view of hollow organ surfaces with white light," Izatt said. "What OCT does is look below those surfaces.

"It can look up to about a millimeter and a half deep into the walls of organs," he added. "That’s sufficient to detect cancers such as carcinomas which grow near tissue surfaces, while they are still small enough to be completely removed. A physician’s normal view of the surface would not see a cancer there, but we can see it with OCT because we are looking underneath."

Izatt acknowledged that light waves cannot penetrate near as far into the skin as ultrasound, a competing technology that uses sound waves to image internal structures. On the other hand, wavelengths of light are much shorter than those of sound. As a result, "OCT’s resolution is much greater," Izatt said.

Rather than using the white light of normal endoscopy, this version of OCT harnesses infrared light from a laser-diode that has had one key laser feature disabled. "Strictly speaking, it is not a laser, but it’s close to being a laser," Izatt said.

While this modified "superluminescent diode" has laser-like "spatial coherence," meaning that its beam remains more focused than normal light, it does not emit light of a single color frequency like complete lasers can.

The special combination of features permits OCT investigators to use it in interferometry. Interferometry is a technique to create visual images by rapidly scanning surfaces with light of various wavelengths while interpreting the return reflections from various depths.

Using a superluminescent diode with interferometry is the "cheapest" form of OCT, Izatt said. And the similarities between this light scanning method and ultrasound delivery systems spurred a natural collaboration, added Smith, who is part of Duke’s ultrasound research program.

The Optics Letters article also included results of several micromachine OCT scans of biological tissue. One examined the lining of an excised pig colon. A second scan probed the cornea and iris of an excised pig’s eye. A third imaged the underside of a human fingertip.

OCT currently has U.S. Food and Drug Administration clinical approval only for scanning the eye’s retina, where the procedure is widely used, Izatt said. It is also being evaluated for various possible imaging uses in the gastrointestinal tract, the lungs, the bladder, the cervix and in coronary arteries, he added.

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

More articles from Process Engineering:

nachricht Applying electron beams to 3-D objects
23.09.2016 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

nachricht New process for cell transfection in high-throughput screening
21.03.2016 | Laser Zentrum Hannover e.V.

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

 
Latest News

New Multiferroic Materials from Building Blocks

29.09.2016 | Materials Sciences

Silicon Fluorescent Material Developed Enabling Observations under a Bright “Biological Optical Window”

29.09.2016 | Materials Sciences

X-shape Bio-inspired Structures

29.09.2016 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>