https://www.mdu.se/

Medical Microwave Imaging (MWI) has been the subject of ongoing research to establish it as a complementary method to conventional clinical imaging modalities. Especially the field of breast cancer detection has seen significant progress in recent years. However, low signal quality remains a persistent challenge, primarily due to spurious signal components, commonly referred to as clutter, that originate within the imaging domain but do not convey information about the internal structure of the breast. Existing strategies to reduce clutter and thereby increase the detectability of a tumor include the application of coupling liquids or contacting antennas, which often fail to meet clinical requirements regarding hygiene, patient comfort, and practical applicability.

To address these limitations, in this thesis, we explore alternative approaches to mitigate clutter in non-contacting, air-based MWI systems aimed at improving clinical feasibility. Specifically, the effect of different field polarizations is being analyzed regarding their potential to reduce unwanted interactions at the air-skin interface. Furthermore, a transmitting field applicator is introduced that leverages reactive near-field interactions for efficient power transmission into the load without the need for direct contact. A mathematical framework based on the boundary element surface method is developed, enabling efficient integration of the proposed strategies into a model-based reconstruction pipeline. In summary, a non-contacting, air-based hardware concept for practical and patient-friendly application is presented together with a computational method for efficient numerical modeling of the system. The contributions made in this thesis advance MWI further towards its potential role as a clinically viable technique for breast cancer detection.