A wireless power transfer system for leadless endovascular electrocorticography

Wireless power transfer (WPT) for stent-based neuroprosthetic devices, such as endovascular electrocorticography (endoECoG) systems, is typically constrained by the need for long lead wires to subcutaneous chest implants. This study presents a method for delivering power directly to an unmodified medical stent. The proposed system employs a subcutaneous relay that converts inductive coupling to capacitive coupling, thereby improving power transfer efficiency, reducing invasiveness, and mitigating instability in skin-contact capacitance. Experimental validation using skin, bone, and vessel tissues, combined with finite element simulations, demonstrated over 45 mW of delivered power, sufficient for endoECoG and biosignal sensing. The proposed system achieved 7.26% DC-to-DC efficiency, the highest reported for stent-based implants without custom stents or auxiliary transceivers. Measured results closely matched simulations, validating the experiment results. Safety assessments, including specific absorption rate and thermal analysis, confirmed compliance with regulatory limits. While the experimental results indicate robust performance, further theoretical analysis is required to establish a complete mechanistic understanding of the underlying coupling processes. The proposed architecture enables efficient, safe, and fully wireless power delivery to endovascular implants without requiring close skin contact, supporting long-term implantation, enhancing patient comfort, and facilitating future clinical translation.