Specific absorption rate in human torso from microwave-based heart failure detection systems

Congestive heart failure is a malignant cardiovascular disease which can be detected by monitoring the accumulation of fluids in the lungs and some other parts of the human body. One of the promising techniques to achieve that target is a microwave-based diagnostic system. To assess the safety of using that technique at different frequency bands, power levels and polarization, the specific-absorption ratio (SAR) inside the tissues of the human torso is to be calculated to make sure their peak values are within the safe levels. This paper investigates SAR distributions inside the torso tissues by looking at the main three factors; frequency, polarization, and distance between the antenna and the human torso. The obtained results give a guide on the maximum power levels for microwave-based systems aimed at the detection of heart failure to comply with IEEE regulation for specific absorption rate (SAR) in the specified operating frequency band.