Imaging of Early-Stage Breast Cancers Using Pulsed Confocal Microwave Technology
Abstract
The work presented in this report is motivated by the need to calibrate a new pulsed-microwave breast tumor detection system for patient-specific skin parameters. A two-dimensional time-domain inverse-scattering algorithm based upon the finite-difference time-domain method is presented for determining the skin thickness and the relative permittivity and electric conductivity of skin in the microwave range. The algorithm traces a search trajectory in the two-dimensional parameter space. The minimal parameter estimation error along this trajectory yields a set of approximate parameter values. It is shown that the convergence of the inverse-scattering technique depends on the shape and the duration of the illuminating electromagnetic wave pulse chosen for the electrical parameter reconstruction. The time-domain nature of the inverse algorithm allows for limiting the region of inversion using causality. Thus, when the parameters of the skin are estimated, the skin thickness can be determined by comparing the measurement with a simulated all-skin response. Finally, the time-domain inverse-scattering algorithm is tested for robustness in the presence of broadband Gaussian noise. We note that the causality of the algorithm can then be exploited for the underlying breast tissue parameter recovery using the same methodology.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2002
- Accession Number
- ADA407479
Entities
People
- Allen Taflove
- Milica Popovic
Organizations
- Northwestern University