Design of coupling medium for pulmonary edema microwave detection system

Microwave systems have the potential to be used as a detection and monitoring tool for pulmonary edema. This target can be achieved by monitoring the accumulation of excessive fluids in human lungs. The main challenge facing such an application is the severe mismatch between the antenna or antenna array and human body tissues at the torso area. Since a low level microwave signal should be used for safety precautions, the mismatch at the antenna-human body interface can mask any meaningful information. To achieve a perfect machining and to increase the dynamic range of the system, a coupling medium with proper electrical properties is to be used at the antenna-skin interface. This paper presents a parametric study on the best possible coupling medium. The study utilizes a realistic human torso that is taken from an MRI image.