Electromagnetic Technologies for Biomedical Sensing and Imaging

This thesis presents innovative electromagnetic (EM) technologies for biomedical sensing and imaging. A flexible microwave spiral sensor has been developed to enable the contactless detection of sub-millimetric air bubbles during hemodialysis, offering a safer alternative to conventional methods. A wearable frequency-coded metasurface has also been designed for non-invasive monitoring of tissue inflammation, with high sensitivity and adaptability. Passive metasurfaces have been developed to significantly enhance MRI performance across multiple field strengths (0.55T, 1.5T and 3T), improving signal-to-noise ratio. Two self-detunable methods have been implemented to switch the metasurface off during the MRI transmission phase. Finally, a reconfigurable metasurface is introduced for low-frequency applications, enabling real-time control of magnetic field distribution. Together, these contributions demonstrate the potential of EM devices to deliver safer, cost-effective, and patient-specific healthcare solutions.