A Novel Development of Endovascular Aortic Stent System Featuring Promising Antenna Characteristics

Abstract

This article presents a deeply implanted stent antenna system for endovascular aneurysm repair (EVAR) to treat abdominal aortic aneurysm (AAA). The stent antenna is composed of multiple helical wires connected to form meshed rings incorporating a single feed wire, thereby precluding the random distribution of currents on the stent-struts. In addition to EVAR application, the key features of the proposed stent system are its better antenna characteristics, including an omnidirectional radiation pattern, high gain, and perfect impedance matching. The proposed stent antenna exhibits wide-band characteristics covering the frequency range from 850 to 950 MHz, including industrial, scientific, and medical bands (i.e., ISM 868 and 915 MHz). Moreover, the stent offers peak gain values of -20.75 and -19.04 dBi at the 868 and 915 MHz bands, respectively. Simulations were performed using the finite-element method and finite-difference time domain to evaluate the properties of the EVAR stent system. For validation, measurements were conducted with a 3-D printed AAA placed in a saline-filled American Society for Testing and Materials phantom and in minced pork. Good agreement between simulation and measured results was observed, thereby serving a first validation of the EVAR stent antenna attributes. A link budget analysis was performed to analyze the biotelemetry capabilities.