Experimental analysis on wireless heating of resonant stent for hyperthermia treatment of in-stent restenosis

Abstract

In-stent restenosis remains the most common problem with stent implantation. Hyperthermia therapy through moderate heating of implanted stent is expected to be an effective treatment for restenosis. Toward this goal, this work investigates a wirelessly powered resonant-heating stent device, with a focus on design improvement and experimental analyses of power transfer and electrothermal behaviors of the developed prototype. The stent device, configured to form a passive resonator with a capacitor-integrated inductive stent, is coated with optimized layers of gold and Parylene C to raise the quality factor and heating performance of the device. Wireless testing of the device deployed in artificial artery shows its promising thermal performance in physiological saline with a flow rate relevant to stenotic blood flow, while revealing clear merits of resonant-based heating with up to ˜220× and ˜40× higher heating rates compared with off-the-resonance conditions in air and saline flow, respectively. The results are used to evaluate wireless heating efficiency, as well as the effects of saline temperature and flow rate on the device performance along with other parameters. The study will pave the path to further design optimization and performance improvement for resonant stent technology towards its application to wireless thermal treatment of in-stent restenosis.