zastosowania elektromagnetyzmu w nowoczesnych ... - PTZE

XVIII Sympozjum PTZE, Zamość 2008
DIFFUSE OPTICAL TOMOGRAPHY
IN BIOMEDICAL APPLICATION
Magdalena Stasiak 1 , Przemysław Berowski 2
1
Department of Electrical Apparatus, Technical University of Lodz,
Stefanowskiego 18/22, 90-924 Lodz, e-mail: stasiak@p.lodz.pl
2
Electrotechnical Institute,
Pożaryskiego 28, 04-703 Warsaw, e-mail: p.berowski@iel.waw.pl
Diffuse optical tomography (DOT) is noninvasive, nonionizing and inexpensive
technique used to measure the optical properties of physiological tissue. In the near-infrared
(NIR) spectral window of 600-1000 nm, photon propagation in tissues is dominated by
scattering rather than absorption. Photons experience multiple scattering events as they
propagate deeply into tissue – up to 10 cm.
In order to solve the forward problem the adequate model of computer simulation and
methods are needed. The Finite Element Method (FEM) and also the Boundary Element
Method (BEM) are the most frequently used among many others. The BEM is an interesting
alternative to the more commonly used numerical methods such as FEM. The principle
advantage of using BEM in EIT is that the discretization is necessary only at the boundary of
analysed domain, what is connected with a significant reduction of the dimension and number
of unknowns from O(N 2 ) to O(N). In this method the partial differential equations (PDE) with
adequate boundary conditions are transformed into an equivalent integral equation set defined
only on the surface of the considered volume. The original integral equation governing
surface potential can be approximated as a summation of surface integrals of each element.
In full paper the BEM approach to problems solution in diffuse optical tomography
will be explained in details.
References
1. Aliabadi M.H., The Boundary Element Method, Volume 2, John Wiley &Sons, LTD, 2002
2. Choe R.: Diffuse Optical Tomography and Spectography of Breast Cancer and Fetal Brain, Dissertation
in Physics and Astronomy, University of Pennsylvania, 2005.
3. de Munk J.C., Faes T.J.C., Heethaar R.M., The Boundary Element Method in the Forward and Inverse
Problem of Electrical Impedance Tomography, IEEE Transactions on Biomedical Engineering, Vol. 47, No.
6, pp.792-800, June 2000.
4. Gibson A.P., Hebden J.C., and Arridge S.R.: Recent advances in diffuse optical imaging, Physics
in Medicine and Biology, 50, R1-R43 (2005).
5. Hillman E.: Development of optical tomography techniques for functional imaging of the neonatal brain,
PhD dissertation, London 2001
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