Recent developments in antenna design for microwave based congestive heart failure detection systems

Congestive heart failure (CHF) is one of the dominant causes of mortality in the world. The most apparent symptom of the disease is the leakage of fluid (mainly water) from blood veins into the lungs. From the microwave perspective, that fluid accumulation alters the effective dielectric properties of the lungs as the accumulated fluid has a considerably higher dielectric constant compared to its surrounding medium inside the lungs. That significant change in the dielectric constant enables the use of microwave systems to detect the presence of the fluid as an early sign of CHF. Antennas as the transmitting and receiving interfaces are the key elements in the design of such systems, which are required for this application to operate at the low microwave frequency bands (around 1 GHz). This paper presents the recent developments in antenna designs for such a system.