Abstract
The ability to retrieve particle size information from back scattering reflectance with a small source-detector separation would significantly enhance the potential for development of non-invasive and minimally invasive diagnostic techniques. We present a technique for inverse determination of particle size distribution and volume fractions and validate it with polystyrene microspheres. Two of monotonic, third-degree polynomial equations were fitted from Mie theory to relate wavelength exponent 'n' and particle radii. These two equations allow us to inversely estimate the particle size from the measured 'n' value. A genetic algorithm was applied to optimize the particle size distribution and volume fraction. The experimental setup consisted of a tungsten light, CCD spectrometer with a bifurcated optical fiber for light delivery and detection. The measurement system was calibrated with a reflectance standard; different sizes and volume fractions of the suspensions were chosen for measurements. The wavelength dependence of reduced scattering coefficient was derived from the measured reflectance. Polystyrene microsphere suspensions with diameters 0.43 - 2.00 μm were characterized using the developed algorithm. The results show a good agreement between the particle size retrieved by our algorithm and manufacturer's data, demonstrating a robust method for particle size determination using near infrared reflectance and small source-detector separation.
Original language | English (US) |
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Article number | 70 |
Pages (from-to) | 359-365 |
Number of pages | 7 |
Journal | Progress in Biomedical Optics and Imaging - Proceedings of SPIE |
Volume | 5693 |
DOIs | |
State | Published - 2005 |
Externally published | Yes |
Event | Optical Tomography and Spectroscopy of Tissue VI - San Jose, CA, United States Duration: Jan 23 2005 → Jan 26 2005 |
Keywords
- Cell size
- Mitochondria
- Nearinfrared spectroscopy
- Particle size
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Atomic and Molecular Physics, and Optics
- Radiology Nuclear Medicine and imaging