three dimensional miniature endoscope

Three-dimensional, miniature endoscope opens new diagnostic possibilities

BOSTON - October 18, 2006 - Massachusetts General Hospital (MGH)

researchers have developed a new type of miniature endoscope that

produces three-dimensional, high-definition images, which may greatly

expand the application of minimally invasive diagnostic and

therapeutic procedures. In the October 19 issue of Nature, the team

from the Wellman Center for Photomedicine at MGH describes their

prototype device and a demonstration of its use in a mouse model.

"This new ultraminiature endoscope is the first to allow

three-dimensional imaging of areas inside the body, " says Guillermo

Tearney, MD, PhD, of the MGH Wellman Center, the report's senior

author. "Its ability to go places that other imaging tools cannot

reach opens new possibilities for medical diagnosis and eventually

treatment."

Standard miniature endoscopic devices - which give physicians access

to hard-to-reach internal organs and structures - utilize bundles of

optical fibers to supply light to and transmit images from the areas

of interest. Larger endoscopes that use image sensors to produce

high-quality, two-dimensional images can be a centimeter or more in

diameter. Existing miniature endoscopes using smaller fiber bundles

may be more flexible but have difficulty producing high-quality

images.

The new device developed at MGH-Wellman uses a technology called

spectrally encoded endoscopy (SEE). Multicolored light from a single

optical fiber - introduced through a probe about the size of a human

hair - is broken into its component colors and projected onto tissue,

with each color illuminating a different part of the tissue surface.

The light reflected back is recorded, and the intensity of the various

colors decoded by a spectrometer, which analyzes the wavelengths of

light. Another device called an interferometer, which calculates

structural information based on the interaction between two waves of

light, provides the data required to create three-dimensional images.