Thoracic fluid detection and monitoring system using metamaterial loaded Yagi-antenna array

The possibility of building a full clinical-system for thoracic fluid detection inside the human torso is explored. Different considerations in building such a system with emphasis on the antenna and platform design is investigated. Various design elements such as type and number of antennas and their required characteristics to build the antenna array is studied. A detailed review on the present systems and their capabilities is conducted. It is shown that due to their ease of fabrication, unidirectional radiation and wide operating bandwidths, planar antennas such as tapered slot and quasi Yagi-antennas are among the most desirable structures for medical-diagnostic and monitoring applications. However, the conventional configurations of those antennas have limited practicality due to their large size. To address this limitation, a mu-negative metamaterial unit-cell loaded Yagi-antenna is shown to be an effective alternative. This antenna is used to build a semi-elliptical array that encloses the circumference of the thorax to scan the torso area. A multi-static scanning approach is devised to acquire scattered signals. The obtained results reveal that the proposed configuration has the potential to detect small amounts of fluid inside the torso and more importantly define its exact location.