Elliptical shape estimation by nonlinear least-squares method for breast cancer using UWB radar technology

Ultra wide band (UWB) microwave imaging has been proposed for detecting small malignant breast cancers and expected to detect breast cancers with safety, less-discomfort and accuracy for high resolution of UWB pulse. However, shape estimation for breast cancers has been remained as a challenge. In this paper, we propose an elliptical shape estimation method by nonlinear least-squares method in order to develop a breast cancer shape estimation using UWB radar technology. We define a regression formula of a nonlinear least-squares method for one cancer considering a two-dimensional (2D) space. We confirm that our method could estimate parameters of an elliptical shape under simple environment using 2D Finite Difference Time Domain(FDTD) calculation. We evaluate the performance of our proposed method under additive white Gaussian noise(AWGN) environment using theoretical signal sets. We could get good results of estimation of 5 elliptical parameters.