Patent ID: 8724864

Claim:
A system for non-invasively examination of internal structures of an object by producing dielectric images utilizing reflection and transmission measurements using microwave radiation, comprising: an antenna array surrounding a region of interest for the examination, a microwave transceiver for measuring reflected and transmitted electromagnetic fields as an electromagnetic pulse, and a computational module for receiving detected radiation and for processing data based on said detected radiation, said computational module further being configured to execute a reconstruction procedure utilized to compute an image of a dielectric profile based on permittivity and conductivity properties of tissue under detection, wherein the reconstruction procedure comprises an iterative computation series performed using at least some frequencies of the electromagnetic pulse, wherein during each iteration computation i) using a same set, or a different set, of frequencies of the electromagnetic pulse as used in a previously iteration computation, a current gradient is calculated at image points, ii) a reconstructed image from a previous iteration is updated to form updated image data that approaches a final image of tissues expected to be found in the image, wherein the reconstructed image from the previous iteration is updated by assigning an a priori dielectric value to the image points where the current gradient value is above a threshold value, the a priori dielectric value assigned to the updated image points being used in a next iteration computation, wherein the iterative computation series ends when a cost functional based on the permittivity and conductivity properties of the tissue is minimize, the cost functional containing a difference between measured image data and updated image data.