An Analysis of the Assumptions Inherent to Near-Field Beamforming for Biomedical Applications

Microwave imaging for biomedical applications is a growing field that shows promise in early patient studies. Interpretation of preclinical imaging results is difficult, in part due to an incomplete understanding of the imaging operator. In this paper, near-field beamforming is demonstrated to be analogous to synthetic aperture radar, and both imaging methods are shown to depend on several simplifying assumptions. The influence of these assumptions is analyzed using analytical and simulated models, and the results are confirmed in an experimental setup. These observations are further explored in application to simulations of realistic breast models as well as patient data.