Procedures for noninvasive electromagnetic property and dosimetry measurements

Five different formulations are presented that can be used to determine local values of the complex permittivity, electric field, polarization current density, and rate of energy deposition, within an inhomogeneous dielectric object of arbitrary shape. These formulations were obtained from the matrix equations for moment-method solutions of the electric field integral equation. Implementation of these formulations requires knowledge of the shape of the object and the incident electric field, and measurements of the scattered electric field at a number of points external to the object. The use of a new type of model, with antenna arrays for measurements, has caused a substantial improvement in matrix conditioning. Results of numerical simulations using 21-cell models with high dielectric contrast (bone/muscle) suggest that all five formulations have sufficient accuracy to warrant experimental testing using cylindrical scatterers with transverse magnetic polarization. >

[1]  J. Richmond,et al.  TE-wave scattering by a dielectric cylinder of arbitrary cross-section shape , 1966 .

[2]  Mark J. Hagmann,et al.  Upper Bound on Cell Size for Moment-Method Solutions , 1977 .

[3]  L. E. Larsen,et al.  Microwave scattering parameter imagery of an isolated canine kidney. , 1979, Medical physics.

[4]  C. Klein,et al.  The use of pivot ratios as a guide to stability of matrix equations arising in the method of moments , 1975 .

[5]  Om P. Gandhi,et al.  Comparison of the FFT Conjugate Gradient Method and the Finite-Difference Time-Domain Method for the 2-D Absorption Problem , 1987 .

[6]  O.P. Gandhi,et al.  Application of Moment-Methods to Electromagnetic Biological Imaging , 1981, 1981 IEEE MTT-S International Microwave Symposium Digest.

[7]  G. W. Hohmann.  Three-Dimensional Induced Polarization and Electromagnetic Modeling , 1975 .

[8]  Procedures for improving convergence of moment-method solutions in electromagnetics , 1978 .

[9]  Inverse scattering solutions of scalar Helmholtz wave equation by a multiple source moment method , 1983 .

[10]  C. Durney,et al.  A Procedure for Calculating Fields Inside Arbitrarily Shaped, Inhomogeneous Dielectric Bodies Using Linear Basis Functions with the Moment Method , 1986 .

[11]  R. L. Levin,et al.  Criteria for accurate usage of block models. , 1987, The Journal of microwave power and electromagnetic energy : a publication of the International Microwave Power Institute.

[12]  Mark J. Hagmann,et al.  Aberrant Heating: A Problem in Regional Hyperthermia , 1986, IEEE Transactions on Biomedical Engineering.

[13]  R. L. Levin,et al.  Convergence of Local and Average Values in Three-Dimensional Moment-Method Solutions (Short Papers) , 1985 .

[14]  A. Stogryn,et al.  Equations for Calculating the Dielectric Constant of Saline Water (Correspondence) , 1971 .

[15]  L. Jofre,et al.  Active microwave imaging of inhomogeneous bodies , 1985 .

[16]  F. B. Hildebrand,et al.  Methods of Applied Mathematics , 1966 .

[17]  R. L. Levin,et al.  Accuracy of Block Models for Evaluation of the Deposition of Energy by Electromagnetic Fields , 1986 .

[18]  A. Guy,et al.  Nonionizing electromagnetic wave effects in biological materials and systems , 1972 .

[19]  Kun-mu Chen,et al.  Electromagnetic Fields Induced Inside Arbitrarily Shaped Biological Bodies , 1974 .

[20]  O. Gandhi,et al.  Numerical Calculation of Electromagnetic Energy Deposition for a Realistic Model of Man , 1979 .

[21]  S. S. Stuchly,et al.  A Solution of Electromagnetic Imaging Using Pseudoinverse Transformation , 1984, IEEE Transactions on Medical Imaging.

[22]  J. Van Bladel,et al.  Some remarks on green's dyadic for infinite space , 1961 .

[23]  Om P. Gandhi,et al.  Use of the Finite-Difference Time-Domain Method in Calculating EM Absorption in Human Tissues , 1987, IEEE Transactions on Biomedical Engineering.

[24]  Mark J. Hagmann,et al.  Estimation of Complex Permittivities of Three-Dimensional Inhomogeneous Biological Bodies , 1983 .

[25]  J. Richmond.  Scattering by a dielectric cylinder of arbitrary cross section shape , 1965 .