Efficient and Reliable Wireless Power Transfer Stent Rectenna System for Abdominal Aortic Aneurysm Surveillance

Abstract

This study presents an innovative wirelessly powered stent rectenna system for endovascular aneurysm repair (EVAR), targeting abdominal aortic aneurysm (AAA) treatment. The system includes an on-body flexible transmitter (Tx) antenna and an in-body rectifier-integrated stent receiver (Rx) antenna, operating in the industrial, scientific, and medical (ISM) band of 868 MHz. The Rx stent antenna, made from a biocompatible nylon-coated metallic wire, ensures mechanical stretchability, biocompatibility, and precise current distribution. The flexible Tx antenna is designed for wearable use. A miniaturized rectifier on flexible polyimide, coated with biocompatible polydimethylsiloxane, converts received power into DC energy. The EVAR stent system's performance is validated through measurements using a saline-filled American Society for Testing and Materials (ASTM) phantom. Magnetic resonance imaging (MRI) compatibility studies using Sim4Life simulations assess potential heating and image artifacts, confirming the proposed stent's MRI suitability. Wireless power transfer experiments demonstrate reliable power delivery to the Rx in various real-world scenarios, achieving a power transfer efficiency of 3.6% at 18 cm inside the phantom. The flexible rectifier shows a peak efficiency of 87% at 15 dBm input power. The proposed system's exceptional performance and efficiency highlight its potential for effectively wirelessly powering advanced AAA stents.