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Proceedings Paper

Heterodyne QELS instrument for diagnostics of biological fluids
Author(s): Andrei D. Lebedev; Mariya A. Ivanova; Aleksey V. Lomakin; Valentin A. Noskin
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Paper Abstract

The instrument for the quasielastic light scattering (QELS), LCS-03 utilizes heterodyne optical scheme which permits a high resolution determination of particle size distribution. The vibration related problems, which are common for the heterodyne techniques, have been overcome by using a single glass block incorporating all the optical elements. The real-time correlation analysis of the photocurrent fluctuations is performed by a PC-embedded analog-to-digit converter card with digital signal processor (DSP) using an original algorithm. Both the technical specifications of the instrument and the software for the size distribution analysis are presented. The heterodyne technique consistently outperforms the homodyne one when the accurate characterization of the particle size distributions in heterogeneous systems is required. Diagnostic analysis of size distribution of particles in blood serum/plasma, liquor and saliva is such an application. This kind of diagnostics usually requires a simultaneous analysis of huge number of QELS data. The original statistical algorithm with graphic user interface is described. We discuss the technical specifications of instrumentation as well as methodical problems of biological fluids QELS diagnostics.

Paper Details

Date Published: 2 May 1997
PDF: 8 pages
Proc. SPIE 2982, Optical Diagnostics of Biological Fluids and Advanced Techniques in Analytical Cytology, (2 May 1997); doi: 10.1117/12.273606
Show Author Affiliations
Andrei D. Lebedev, St. Petersburg Institute of Nuclear Physics (Russia)
Mariya A. Ivanova, St. Petersburg Institute of Nuclear Physics (Russia)
Aleksey V. Lomakin, Massachusetts Institute of Technology, Harvard Medical School, and Brigham and Women's Hospital (United States)
Valentin A. Noskin, St. Petersburg Institute of Nuclear Physics (Russia)


Published in SPIE Proceedings Vol. 2982:
Optical Diagnostics of Biological Fluids and Advanced Techniques in Analytical Cytology
Robert C. Leif; Alexander V. Priezzhev; Toshimitsu Asakura; Robert C. Leif, Editor(s)

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