Password Magazine - Issue 24

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New techniques for molecular imaging

Scientists at Philips are investigating fast quantitative Magnetic Resonance (MR) acquisition and data-analysis techniques for molecular-imaging applications. Evaluation of the techniques clearly indicates that quantitative MR imaging is a powerful tool for monitoring the effects of therapy in follow-up studies and shows great promise for early assessment of diseases in the future.

The aim of molecular imaging is to provide early detection of pathological processes associated with disease at the cellular and molecular level rather than at anatomical level as in conventional diagnostic imaging. The quantification of molecular-imaging agents is crucial for assessing disease progression or regression after therapy. The Philips researchers have implemented fast, robust and easy-to-use fitting and correction software tools for the generation of relaxation rate maps (the crucial parameters in MR imaging).

“We have evaluated the effectiveness of our techniques in collaboration with luminary sites. The results strongly support the conviction that quantitative MR offers high potential as a tool for the improvement of diagnosis and staging of diseases, as well as for monitoring of treatment response,” said Tobias Schäffter, principal scientist of the project at Philips Research.


For more information, see

+ www.research.philips.com/newscenter/archive/2005/050623-
aachen-quantitativemri.html

 

 

Comparison of a conventional relaxationweighted contrast (top) with the concentration map obtained with the quantitative MRI methods (bottom) for the diagnosis and staging of liver tumors. Data courtesy C. Bremer,W. Heindel, University Hospital Münster.

 

An SMS at your pillow?

One of Philips Research’s demonstrations at the Internationale Funkausstellung (IFA) 2005 in Berlin, will be photonic textiles—fabrics that contain lighting systems and can therefore serve as displays.

At first glance, objects such as clothing, towels, upholstery, and drapes would seem unlikely places on which to place intelligent and interactive systems.Yet these low-tech objects figure prominently in our lives. By integrating flexible arrays of multicolored light-emitting diodes (LEDs) into fabrics—and doing so without compromising the softness of the cloth—Philips Research is bringing these inert objects to life.

To meet the challenge of creating light-emitting cloth objects that retain their softness, Philips researchers have developed an interconnecting substrate made entirely of cloth.They have also created flexible and drapable substrates from plastics and films. On these substrates, the researchers have placed passive matrixes of 10 x 10 red, green and blue LED packages. The pixelated luminaries have been embedded in such everyday objects as pillows, backpacks, and floor mats, and prototype samples will be shown at the IFA.

 

Applied in soft fabric, the light from the small pixels diffuses, resulting in a more or less continuous light-emitting soft surface.

 

Great bass for small products

With ‘BaryBass’, Philips scientists have demonstrated the world's first miniature, lowfrequency sub-woofer. This groundbreaking development in audio technology allows deep bass reproduction from a small loudspeaker enclosure, something that has long been considered a 'holy grail' in the audio world.The technology opens up new possibilities in adding a true bass sound to integrated flat TV loudspeakers, miniature portable digital audio players and even in-car entertainment systems.

“The BaryBass loudspeaker operates at its resonant frequency, which means its efficiency can be much higher than for a normal loudspeaker,” says Ronald Aarts, Research Fellow at Philips Research.“We constructed the loudspeaker in such a way that resonance occurs at a very low frequency, i.e. a bass tone. The rest of the low-frequency tones, in this case up to 120 Hz, are all mapped onto this single frequency, where efficiency is at a maximum.The frequency range above this is undisturbed.”

Tests have confirmed that BaryBass produces a true deep bass sound. Another advantage of the BaryBass technology is that the loudspeaker enclosure can be shaped in an arbitrary way, so its form can be adapted to suit the constraints of the product.

For more information, see:

+ www.research.philips.com/technologies
/syst_softw/dsp/barybass/index.html
 

 

Measuring the audio characteristics of a BaryBass loudspeaker unit.

 

Towards 250-Gbyte optical discs

At the International Symposium on Optical Memory and Optical Data Storage (ISOM/ODS) held in Hawaii, Philips showed research results on near-field optical recording, a possible solution to further increase the storage capacity of optical discs. While double-layer DVDs store 8.5 Gbyte and double-layer discs of the Blu-ray Disc format will hold 50 Gbyte, near-field recording seems a promising candidate to boost the capacity of optical discs up to the quarterterabyte (250 Gbyte) regime.

Increased optical storage density is achieved by reducing the spot size of the laser beam that reads and writes the data on the disc. In the near-field approach, this is achieved by a solid immersion lens (SIL). This increases the numerical aperture (optical strength) of the lens to far above unity, the fundamental limit for focusing in air.

However, the use of an SIL requires a distance between the disc and lens of less than 40 nm, posing a tough engineering challenge, given the fact that the (removable!) optical discs are usually not flat and perfectly clean. At the symposium, the Philips scientists showed a fast and robust tracking system based on conventional actuators used in DVD systems. They also showed the feasibility of applying a protecting cover layer on the discs, which would greatly enhance the robustness of the system.

One of these papers was rewarded the Best Paper Award at the ISOM/ODS conference.
 

 

Near-field optical recording uses the evanescent field outside a solid immersion lens to read and write data on the optical disc.