Abstract:
Microwave imaging is renowned as one of the most promising technologies in the medical
application of abnormality or lesion diagnosis. The underlying concept ofactive microwave
imaging is to diagnose a lesion by evaluating the large dielectric difference between normal
tissue and abnormal tissue employing antennas as the key element. A salient feature of
microwave imaging antenna is attributed to its ultra-wide impedance bandwidth as found
in the previous research works. In this research work, an ultra-wideband (UWB) bow-tie
antenna and a monopole antenna are designed and analyzed for simultaneous detection and
localization of brain tumor and brain stroke respectively using a microwave imaging
technique. The bandwidth enhancement of the proposed bow-tie antenna is accomplished
by dint of a self-complementary structure while the bandwidth of the proposed monopole
antenna is enhanced with defected ground structure (DGS) and trident-shaped feeding strip.
Furthermore, a six-layered human head phantom composed of skin, fat, bone, dura,
cerebrospinal fluid (CSF), and brain is modeled in which a malignant tumor, hemorrhagic
stroke, and ischemic stroke are inserted individually upholding the safety regulation of
specific absorption rate (SAR). In addition, the monostatic radar-based delay-and-sum
(DAS) beam-forming or confocal microwave imaging algorithm is developed for
visualizing the location of the lesion explicitly via image reconstruction. It is exposed from
the simulation results that the proposed bow-tie antenna achieves superior performance to
the conventional counterparts, specifically, in respect of bandwidth and radiation efficiency
whereas the proposed monopole antenna attains superiority regarding bandwidth and size
in particular. Brain tumor detection is assured with a drastic improvement of current density
and SAR of the proposed bow-tie antenna compared to the normal healthy tissue. However,
the hemorrhagic stroke is detected with an excess of current density and SAR of the
proposed monopole antenna in comparison to the healthy brain while the situation reverses
in the case of the ischemic stroke. Eventually, the relevant microwave images are
reconstructed reliably in two-dimension with a high spatial resolution. Hence, the proposed
research work might save human lives by the alleviation of mortality rate due to brain
abnormalities through an early and quick diagnosis.
