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Date: February 24, 2006
Author: Jonathan Bell

FREE ADMISSION SATURDAY FEATURES GUEST SCIENTISTS WHO HARNESS THE POWER OF LIGHT

Imagine a hand-held medical device that uses a stream of photons (particles of light) to detect and treat disease without ever invading our bodies. What may have once seemed an impossible dream of Star Trek fans is now slowly becoming a reality through a relatively new, interdisciplinary scientific field, called biophotonics. 

Tomorrow Explorit Science Center will host visitors from one of the leading biophotonics research centers, the Center for Biophotonic Science and Technology (CBST), as they provide a number of interactive experiments for people interested in learning more about this new field.

The CBST will be on hand 1 p.m. to 3 p.m. tomorrow, and admission is free. 

Through a variety of experiments guests will learn how light can be used to see the invisible. There will be a device available to measure heart rate and the percentage of oxygen in blood using a beam of light directed through a finger. Invisible writing will appear in the presence of certain types of light as will hidden images on California Drivers licenses and new $20 bills. Guests will also be able to see some of the amazing things that are visible in the mid-infrared range such as their own handprint, left as heat, on a piece of paper.

The CBST, based at UC Davis, defines biophotonics as " the science of generating and harnessing light (photons) to image, detect, and manipulate biological materials." Basically, biophotonics is the study of how photons interact with living tissue. Eyes and plants' leaves are both examples of advanced biophotonic tools. Photons are the basic unit of light, or electromagnetic radiation. Electromagnetic radiation includes x-rays, radio waves, microwaves, infrared light, ultraviolet light and of course, visible light.   

Some aspects of this burgeoning new field are already familiar medical tools. X-rays are one example. The self-serve oxymeters found in some pharmacies that detect oxygen levels in the blood are another. Both these technologies work by passing photons vibrating at a specific frequency through living tissue.

There are also photonic meters that measure pulse, body fat, oxygen content of the blood and body temperature. 

Light-based approaches for detecting and eradicating cancer are being explored. Photodynamic therapy for osteo sarcoma is a process similar to chemotherapy in many ways, the significant difference being the cancer-destroying compound. In traditional chemotherapy those compounds are active as soon as they enter the body, whereas in light therapy they are inactive until exposed to a particular form of light.

Newer imaging techniques, such as optical coherence tomography, will allow for very early detection of cancer. This process is similar to ultrasound imaging but uses near-infrared radiation instead. This may someday allow researchers to create accurate images taken at a cellular level within dense tissue.

The CBST's presentation, " What is Biophotonics?" is sponsored by Davis Waste Removal. It's a great tie-in to Explorit's current exhibition, " Catch a Wave: The Science of Light and Sound." Admission to the presentation and the exhibition tomorrow are free.

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Explorit Science Center is at 3141 Fifth St. in East Davis. The current exhibition "Catch a Wave: The Science of Light and Sound" runs through Mar. 12. Public hours are Saturday and Sunday from 11 a.m. to 4:30 p.m. and Tuesday through Friday from 2 to 4:30 p.m. For more information, visit www.explorit.org or call Explorit at (530) 756-0191.