optoelectronic world
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scanning system, theoretical transverse and axial resolutions were computed to be 1.0 and 3. 6 µm, respectively. Assuming aberration-free operation, the theoretical spectral resolution on the sample was 0.08 nm with a maximum of approximately 630 resolvable points across the
spectrally encoded 500 µm line.
The researchers tested their confocal microscopy system on a U.S. Air Force resolution chart mounted on a piece of lens paper affixed to the interior of a cylinder, as well as on a swine intesti-nal-tissue fragment. For the swine intestinal tissue, images were displayed
at magnifications of 1×, 4×, 20×, and 40× (see figure). Magnified images of the tissue demonstrate features consistent with intestinal villi, containing bright reflective dots that may be nuclei or intracellular vacuoles.
According to researcher Dvir Yelin, several challenges remain before the SECM technique can be applied in a clinical setting. First and foremost, miniaturization of the optics, motor, and housing is required. A method for precise centering of the imaging optics needs to be developed, along with faster data acquisition and processing. “Once these technical issues are resolved, the acquired microscopic data sets will be huge,” says Yelin. “In order to manage this information, we will additionally have to develop a user interface, where a physician can examine the dataset at low power, and gradually zoom in to specific sites to inspect cellular and subcellular structures.”
Guillermo Tearney, a pathologist and senior author on the paper, believes that this technique may usher in a new paradigm for medical diagnosis. “Instead of excisional biopsies, which often represent only small portions of the area of interest, this technique could significantly increase diagnostic yield by rapidly and noninvasively imaging an entire epithelial surface with microscopic resolution,” says Tearney.
Gail Overton
REFERENCE
1. D. Yelin et al., Optics Lett. 32( 9) 1102 (May 1, 2007).
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