Time reversal mirror for hyperthermia of multi-focal breast tumors using electromagnetic time reversal technique

ABSTRACT Motivated by the quest to curtail the high mortality rate of breast cancer, the manuscript proposes the sensitivity enhancement of monopole antenna for hyperthermia application by using electromagnetic time reversal (EMTR) technique with transformation structures for early treatment of multi-focal breast tumors. The EMTR technique is characterized with temporal and spatial focusing, hence enhancing the visibility of tumors embedded in the breast medium. In this study, we aim at the non-invasive power deposition on sub-wavelength-sized tumors at sub-wavelength separation incorporation with sub-wavelength scatterers. The paper is focused on enhancing the sensitivity of scattering reception in TR algorithm for hyperthermia application using sub-wavelength sized scatterers. The proposed applicator is an ultra-wideband (UWB) monopole antenna designed with sub-wavelength-sized split ring embedded square patch (SRESP) on a grounded substrate placed below it at some distance to serve as near field scatterer. Another plate of sub-wavelength scatterers but without the ground plate is placed in close proximity to the unhealthy breast in-conjunction with four ultra-wideband antenna time reversal mirrors (UWB-TRM). The proposed method shows promising potential for the selective power deposition for hyperthermia of sub-wavelength-sized tumors at sub-wavelength separations. This technique of enhancing front-end sensor sensitivity can also be extended to other optimization techniques for selective power deposition in hyperthermia of breast cancer.