Miniaturized Epidermal RFID-Based Wireless Programmable Frequency Selective Surface as a Smart Shield for Implantable Cardiac Devices

Modern Implantable Medical Devices (IMDs) pro-vide wireless connectivity for remote monitoring and program-ming. Despite of the benefits in term of accessibility, this connec-tivity also exposes IMDs to potential cybersecurity and physical threats, compromising patient safety. In this paper, we propose a novel miniaturized unit cell of an epidermal Radio-Frequency IDentification (RFID)-based wireless programmable Frequency Selective Surface (FSS) designed to protect IMDs from unau-thorized electromagnetic interference (EMI) and ensure secure communications. The proposed shield minimizes power require-ments and achieves a highly compact form factor by employing four Single-Pole-Single-Through (SPST) switches for each unit cell instead of conventional PIN diodes. Numerical simulations and experimental evaluations confirm the efficacy of the shield in attenuating signals in the Medical Implant Communication Service (MICS) band, with a shielding effectiveness of more than 25 dB, while it is almost invisible when communication is enabled. This solution represents a novel approach to enhancing the resilience of IMDs against physical and cyber threats.