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Proceedings Paper

Measurement system for noninvasive dynamic optical topography
Author(s): Yuichi Yamashita; Atsushi Maki; Hideaki Koizumi
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Paper Abstract

We have developed a 24-channel simultaneous measurement system for optical topography that noninvasively obtains dynamic images of brain activity over a measurement area of 90 mm by 90 mm. To evaluate the system performance, we utilized a phantom containing a rotating absorber in a cylindrical scattering medium. In this system, eight incident and eight detecting optical fibers are arranged alternately at points of a square lattice on the phantom. The phantom is illuminated with light of two wavelengths (780 and 830 nm) from each incident fiber. Reflected light is received by the detecting fibers, each of which is connected to an avalanche photodiode. Multiple modulation and lock-in detection are used to enable highly sensitive measurement with negligible crosstalk (less than -50 dB). In the phantom measurement, we obtained topographic dynamic images of the absorber rotating in the medium with a temporal resolution of 0.5 s.

Paper Details

Date Published: 15 July 1999
PDF: 6 pages
Proc. SPIE 3597, Optical Tomography and Spectroscopy of Tissue III, (15 July 1999); doi: 10.1117/12.356816
Show Author Affiliations
Yuichi Yamashita, Hitachi, Ltd. (Japan)
Atsushi Maki, Hitachi, Ltd. (Japan)
Hideaki Koizumi, Hitachi, Ltd. (Japan)


Published in SPIE Proceedings Vol. 3597:
Optical Tomography and Spectroscopy of Tissue III
Britton Chance; Robert R. Alfano; Bruce J. Tromberg, Editor(s)

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