Quantification of the optical properties and hemoglobin of tissue phantom using a hyperspectral imaging-based system
Date Issued
2010
Date
2010
Author(s)
Chen, Chun-Yu
Abstract
In this thesis, we present a method for the analysis of diffuse reflectance spectra obtained from tissue-simulating phantoms using a reflectance hyperspectral imaging system, The goal is to quantify scattering coefficient , oxygen saturation and hemoglobin concentration in vivo.
Spatially-resolved reflectance spectra were measured from tissue phantoms through optical fibers by using a hyperspectral imaging system based on Fourier transform spectrometry . A novel Monte Carlo scaling method was used to speed up forward simulations of reflectance spectra. Inverse modeling was performed with the Levenberg-Marquardt algorithm to estimate the absorption and reduced scattering coefficients from the measured spectra . Oxygen saturation and total hemoglobin concentration in tissue phantoms were derived from the absorption coefficient.
We implemented the novel Monte Carlo scaling method by using C++. Compared with the original Monte Carlo algorithm, the scaling method can reduce computation time by nearly 3 orders of magnitude, and the error was less than 3%. The novel Monte Carlo algorithm can be used obtain spatially resolved reflectance spectra of tissue with different optical parameters without significantly affecting simulation time, which is ideal for building spectral databases.
The inverse model was built with the Matlab GUI interface and provided two different approaches for predicting optical properties depending on the user''s need. Reduced scattering coefficient can reach 98% accuracy, and the accuracy of extracting absorption coefficient is 93%.
We obtained reflectance spectra from a tissue simulating phantom which was composed of agarose, scatter was achieved with a suspension of polystyrene spheres and an absorber was used human hemoglobin. Data was analysis from 0.06cm, 0.10cm and 0.14cm . Hemoglobin concentration on the actual measurement error were -12.01% , -10.64% and -12.71% , respectively .Reduced scattering coefficient error were 11.66% , 8.55% and 2.37%, respectively. Absorption coefficient error were 12.07%, 10.64% and 12.71%, respectively.
Subjects
Monte Carlo modeling
diffuse reflectance
optical tissue characterization
phantom
Fourier transform spectrometer
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-99-R97945028-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):a46d8b0478c40dd12e9c0a73a9151289