Optics meeting tips: Internal fingerprints, no cell left behind, 3-D reality

09/23/04

September 23, 2004--The Frontiers in Optics 2004/Laser Science XX meeting, the premier annual gathering place for members of the Optical Society of America, will take place October 10-14, 2004 at the Rochester Convention Center in Rochester, NY. In addition to quality and cutting-edge content, attendees will have the opportunity to attend The Institute of Optics' 75th Anniversary Celebration at the University of Rochester, and other topical meetings on optics.

A meeting pressroom will be located in the Rochester Convention Center, Aqueduct A Room. The pressroom's hours are Monday, October 11, 8 a.m. - 7 p.m., Tuesday and Wednesday, October 12 and 13, 8 a.m. - 5 p.m. and Thursday, October 14, 8 a.m. - 2 p.m. Those interested in obtaining a meeting badge for the pressroom should contact OSA's Colleen Morrison at 202-416-1437, cmorri@osa.org.

PLENARY SESSION FEATURING NOBEL PRIZE WINNERS, VISIONARY SPEAKERS AND SENATOR HILLARY RODHAM CLINTON Conference plenary and awards sessions feature three visionary speakers, an address from Nobel Prize winners and a keynote presentation from Senator Hillary Rodham Clinton (D-NY).

In the conference plenary, Kerry Vahala of Caltech, in his talk entitled "Minding the V's and Q's of Optical Microresonators," will provide a tour of tiny devices for confining and controlling light and discuss their novel applications. In "Bio-photonics," Watt Webb of Cornell University will discuss recent advances in imaging and studying tiny biomolecular structures using the whole range of the electromagnetic spectrum. To deepen basic understanding of optics and advance technology, the third visionary speaker, the University of Rochester's Emil Wolf, will trace optics history from the 1860s to the 21st century to present a new development of which he played a major part: a recently developed unified theory of coherence and polarization, two key properties of light waves. Senator Clinton will also speak, touching on the impact of optics in the state of New York. (Monday, October 11, 4:00 p.m.)

In a separate session the following morning, Steven Chu, Lawrence Berkeley National Laboratories, Claude Cohen-Tannoudji, Collge de France and William Phillips, National Institute of Standards and Technology will participate in a panel discussion. Chu, Cohen-Tannoudji and Phillips are the recipients of the 1997 Nobel Prize in Physics for development of methods to cool and trap atoms with laser light and are OSA's newest Honorary Members. Moderated by OSA President Peter Knight, this panel discussion will focus on the moment these scientists knew that they had made a Nobel-worthy discovery and the way this discovery has impacted and directed their current research. (Tuesday, October 12, 7:30 a.m.)

HIGHLIGHTS
Following are a few of the many highlights to be discussed at the meeting.

FINDING A VEIN

Finding a vein, necessary for administering intravenous solutions, can often be difficult. A new device, called a Vein Contrast Enhancer (VCE), uses sensitive infrared sensing to find the vein beneath the skin and then also projects the rather spooky vein image back onto the patient's wrist. This makes it appear as if the veins were lying right on top, making it easy for a nurse to make an injection.

How does it work? An array of light-emitting diodes shines infrared light at the subject, and one depends on the fact that red blood cells scatter light differently from surrounding fatty tissue. The scattered light passes through some filters and then is captured by a sensitive TV camera, processed by computer, and rendered as a sort of movie at a rate of 30 frames per second. These images can be projected onto the subject through a careful aligning process to register the surface projection with subcutaneous anatomy. Herbert Zeman and his colleagues at the University of Tennessee Health Science Center in Memphis have done extensive clinical trials with VCE devices and are now doing trials with the projection capability. The general spatial resolution of the process is about 0.1 mm. Veins as deep as 8 mm have been imaged. (Paper FTuL3, Tuesday, October 12, 2:45 p.m. See also http://www.conenhill.com/)

NO CELL LEFT BEHIND

How can a surgeon be sure that no cancer cells are left behind during surgery? Or better yet, what if some cancer patients could skip exploratory surgery and have suspicious areas examined with an endoscope? Irving Bigio of Boston University, and clinical collaborators in London, may have an answer. His team has constructed a fiber-optic probe that is inserted through an endoscope that will measure via spectroscopy the structural properties of cells in tissue. For example, cancerous cells can be identified by changes in size or density of sub-cellular components like the nuclei. Bigio's research takes the spectroscopic measurements in vivo, and collects real-time measurements. Then a surgical biopsy (removal of a sample of the tissue for microscopic examination by a pathologist)-the current gold standard of diagnosis-is done. So far, Bigio says, the spectroscopy results compared to pathology reports from biopsies are "promising." To make it clinically practical, he adds, diagnostic algorithms would need to be created to process the information in real time, and larger-scale studies would need to be done to prove efficacy. "This is not replacing pathology, but it would help to refine where pathology happens, something we call 'guided biopsy'." (Paper FTuL4, Tuesday, October 12, 3:00 p.m.)

AN INTERNAL FINGERPRINT

In the recent movie "Minority Report," the main character has his eyeballs swapped out in order to fool a biometric retina scanner. Now, Robert Rowe of Lumidigm, Inc. introduces a system for fingerprint identification that is almost as hard to fool as the movies can imagine. The new sensor uses multiple colors of light to measure the subsurface structure of the finger, sending visible light and very near infrared light into the finger. This new development builds on work that shows that tiny capillaries under the fingerprint also have distinct patterns, and the blood that the capillaries carry can be easily measured by the light sensor. They've even tested it against fake fingers to ensure that the system can't be spoofed. The system could easily integrate into some of today's fingerprint scanners. The spoof-detection technology should be available in mid-2005, when the company will target federal applications and other large-scale implementations where it is important to quickly find out whether a fingerprint is genuine. (Paper FTuL6 Tuesday, October 12, 3:45 p.m.)

QUICK MEASUREMENT FOR DETECTING EARLY SIGNS OF CANCER

Patients with chronic diseases that may lead to cancer need a means for monitoring tissue health, without invasive and non-definitive biopsies. Adam Wax of Duke University is providing a way to detect pre-cancerous cells in intact tissues in just one second with a technique called angle-resolved low-coherence interferometry (a/LCI). To find pre-cancerous cells, a/LCI shines light that can look beneath the tissue surface and measures cell features with a sensitivity smaller than the wavelength of light. One of the earliest changes in pre-cancerous cells is that the cell's nucleus enlarges, which changes its light scattering properties, and this can be seen by a/LCI. The interferometer records the angular distribution of light scattered by a small region of tissue, even beneath the tissue surface where cancer begins.

The new technique takes a measurement in 40 milliseconds, and it can process the data, determine the size of the cell nuclei and make a diagnosis in less than a second. This technique, developed in collaboration with Duke graduate student John Pyhtila, measures the frequency variations of the light returned and in one fell swoop acquires the entire light-scattering pattern over a wide range of angles, instead of acquiring measurements one by one, which used to take five minutes per measurement. Wax anticipates that the first clinical trials in human subjects with esophageal cancer will begin in about two years. (Paper FTuR1, Tuesday, October 12, 4:15 p.m.)

3-D REALITY WITHOUT THE REAL

Conventional 3-D displays force our eyes to do two conflicting things at the same time, for instance, pointing our eyes to look at something that appears to be far away, but having to focus the lenses of our eyes up close. But this unnatural eye pose is tiring and gives people headaches. It's easier and more natural for our eyes to focus at the same place that we're pointing them. Brian Schowengerdt at the University of Washington's Human Interface Technology Laboratory has a new 3-D display, called True 3D, that matches what's most easy on the eyes.

With the True 3D scanned-light display, light from different objects seems to come from different distances in space. This is made possible by a tiny stretchable mirror made of a thin membrane, just 10 millimeters across, coated with aluminum. The deformable mirror stretches on command to change the focus of each pixel of light as the display projects different objects. Just one tiny mirror can control all the pixels in the display as it scans by changing the focus of that beam very quickly -in this case, twice as fast-as the display refreshes. Viewers can converge their eyes and focus their eyes at the same distance - just like when viewing real objects. Also as in real life, no screen is needed to see the objects - the display changes the light's intensity and color, so "a high-resolution full-color picture can be painted right onto the retina," Schowengert said. (Paper FThA2, Thursday, October 14, 8:15 a.m.)

SHEDDING NEW LIGHT ON EMBRYONIC CELL DEVELOPMENT

Chi-Kuang Sun of the National Taiwan University will present a new high-resolution optical technique for imaging the embryonic development of living organisms non-invasively in their natural environments. Demonstrated in the zebrafish, a modern vertebrate studied widely in genetics and developmental biology, the technique could potentially be applied to following the development of human stem cells. Infrared laser light safely penetrated all the way through the zebrafish embryo and yielded highly detailed images (400-nanometer resolution) of its interior, enough to discern important cell features such as the neural tubes, structures which later develop into the spinal cord, spine, and brain. Never has any laser-based technique produced such high-resolution pictures of a living specimen with such good depth penetration. Called "harmonic optical microscopy," the technique scans infrared laser light across the living specimen, which then generates light in the second and third harmonics (having two and three times the frequency of the initial infrared light). Detectors capture this "higher harmonic" light to build up images of the specimen. By using light that does not get absorbed by the embryo, Sun could continuously image the embryo for 12 hours without heating it or otherwise damaging its viability. Other laser-imaging techniques cannot do the same, as they risk heating the sample. Moreover, the technique can follow the zebrafish's complicated development, from initial cell proliferation to tissue formation, without the use of any dyes. (Paper FWN3, Wednesday, October 13, 2:15 p.m.)

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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