Three-Dimensional Electromagnetic Torso Imaging Using Reconfigurable Antennas

Thoracic disorders, such as lung and liver cancer, and congestive heart failure are the major causes of chronic morbidity and mortality in the world. Electromagnetic imaging (EMI) is an emerging technique to diagnose those abnormalities in a fast and cost-effective way. In that regard, a portable human torso scanner, including a pattern reconfigurable metasurface antenna as a data acquisition device and a three-dimensional backpropagation method as an imaging algorithm are proposed. The utilized antenna consists of three rectangular microstrip-fed slot radiators to scan the torso in the bandwidth of 0.8-1.15 GHz. The image construction algorithm is then utilized to detect the locations of contrasts in dielectric properties of tissues, which are due to abnormal tissue. To that end, the electromagnetic power intensity inside the three-dimensional imaging region is estimated by combining a backpropagation technique with an interpolation method. The proposed method is successfully tested in measurements by detecting 20 mL accumulated water inside lungs of a human torso phantom as an emulation of pulmonary edema. The obtained results show that the proposed technique enables the accurate detection and localization of the target.