Future Endoscopes Could Incorporate Infrared Optical Coherence Tomography

Developed by scientists at the University of Florida (UF, Gainesville, USA), the laser-powered endoscope is based on optical coherence tomography (OCT). The laser beams through the arm of an OCT scope, hits the tissue, and reflects some light back, while the rest scatters; an interferometer measures the reflected light and subtracts the scattered light. Altering the length of the arm alters the depth at which light is directly reflected back, producing images of different layers, which together form 3D imagery of potential tumors forming within tissue. The prototype device uses a micro-electromechanical system (MEMS)-based approach, centered on a tiny, one-by-one-millimeter mirror that can pivot at a rate of 200 Hz with the help of tiny actuators; as infrared light beams down the endoscope, the mirror steers the light back and forth, illuminating a slice of tissue. The reflected light bounces back up the endoscope, and is analyzed and depicted on a screen in real time. The IR laser powered endoscope was described in the December 3, 2009, newsletter of the journal Technology Review.

"Eighty-five percent of cancers originate from the epithelium, which is about two millimeters deep,” said lead researcher Huikai Xie, Ph.D., an associate professor of electrical and computer engineering and director of the UF biophotonics and microsystems laboratory. "If you need to remove the tumor, the surgeons have a hard time determining when to stop. With a real time, high-resolution tool, they will be sure.”

The prototype is still too big to use in humans, as it requires a total diameter of 5 mm to fit all its parts. However, Dr. Xie plans to miniaturize further the design, and is planning to test it in larger animals such as pigs and goats in 2010. He recently started a company, WiOptix (Gainesville, FL, USA), and is seeking funding from the U.S. National Institutes of Health (NIH) to help commercialize the technology.

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