Orthogonal Bases for Biomedical Inverse Scattering

we present an orthonormal parameterization of the complex dielectric susceptibility for a collection of tissues relevant to diagnostic microwave imaging. We have considered frequencies in the range 1.0 GHz to 4.0 GHz, which is common for medical applications of microwave imaging. We provide an analysis of the commonly used monopole Debye model, showing poor conditioning between two of its basis functions. Analysis on multi-frequency sensitivity matrices show that our parameterization generally yields lower condition numbers than equivalent scenarios using the Debye basis. Finally, we present examples of image reconstruction comparing the use of these different bases.