Research Projects

The goal of this research is to recover the spatial electric property of tissue and generate a 3D map of the breast by solving inverse scattering problem. Three dimensional (3D) microwave imaging of the breast can be used for hyperthermia treatment planning of locally advanced breast cancer using phased array of antennas. MWI comprises two main modalities, microwave tomography, and ultrawide band (UWB) RADAR. Microwave tomography is the process of generating 2D image of a slices or sections of a 3D object. It has been reported that the dielectric properties of breast cancer overlap with the glandular breast tissue. Thus, it is essential to image the dielectric properties of the breast for accurate estimation of the phased array excitation. Microwave imaging setup includes various components like an antenna array, microwave front-end with switching circuit, data acquisition system, control board, and signal and data processing unit. A phased array of UWB antenna is used for MWI to record the backscattered signals. The UWB antenna in the array will be designed with improved power coupling stability and reduced cross-coupling between the array elements. The salient features of the UWB antenna that will attempted in the design phase are compactness (30×30 mm²) and cross-coupling less than −20 dB. Furthermore, antennas in the array must be capable of providing stable similar performance for varied tissue and breast density. The amplitude difference and phase difference of transmitted signals are affected by the tumor. The amplitude and phase difference between transmitted and backscattered signals is used by the reconstruction algorithm. Dielectric imaging using microwave tomography is inverse problem which will be implemented using an iterative procedure. The forward problem is solved to enhance precision and accelerate imaging process with the aid of Log transform for optimization. The inverse scattering problem addresses non-linearity and ill-posedness in the matrices derived from the back scattered signals. In each iteration, the permittivity value will be updated until the estimated back scattered signals match the ground truth measurements. This imaging technique has the potential for detecting breast cancer, monitoring tumor shrinkage during systematic treatment of tumors and generating patient-specific 3D dielectric model for hyperthermia treatment planning.