Empowering Remote Patient Monitoring With a Dual-Band Implantable Rectenna System for Wireless Power and Data Transfer
Muhammad Zada, Izaz Ali Shah, Jamal Nasir, Abdul Basir, Hyoungsuk Yoo
Abstract
Remote patient monitoring can improve healthcare outcomes by enabling patients to receive continuous care at home. However, a reliable and convenient means of wireless communication and power transfer is needed to drive implantable biomedical devices. In this study, a complete wireless power transfer (WPT) system and data transmission for remote patient health monitoring is proposed, comprising an implantable receiver (Rx) antenna, an efficient rectifier integrated with the Rx, and a transmitter (Tx) antenna. The implantable Rx antenna has small footprints with dimensions <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi \times 5^{2}\,\,\times0.75$ </tex-math></inline-formula> (58.9 mm3) and exhibits dual-band characteristics: 915 and 2450 MHz for simultaneous wireless power reception and data transmission, respectively. The rectifier of a similar size to the antenna was optimized to operate at 915 MHz with an RF–dc conversion efficiency of 82%. The individual components of the WPT system were simulated, optimized, fabricated, and measured for scattering parameters and gain in a saline-filled 3-D head phantom and minced pork. The implantable antenna and rectifier were then integrated to form a compact rectenna system. A demonstration is performed in the realistic scenario to determine the power reception capability of the proposed implantable rectenna system. For safety purposes, specific absorption rate (SAR) and temperature analysis were conducted and found to be within acceptable limits. Finally, to verify the reliability of the communication link with an external unit, the received power was measured, and the implantable Rx element was found to be capable of effectively communicating over distances of up to 2 m. Our results suggest that this technology has the potential to greatly improve the adoption and effectiveness of remote patient health monitoring, by providing a convenient and reliable means of wireless communication and power transfer.