Title | An MRI Compatible RF MEMs Controlled Wireless Power Transfer System. |
Publication Type | Journal Article |
Year of Publication | 2019 |
Authors | Byron K, Winkler SA, Robb F, Vasanawala S, Pauly J, Scott G |
Journal | IEEE Trans Microw Theory Tech |
Volume | 67 |
Issue | 5 |
Pagination | 1717-1726 |
Date Published | 2019 May |
ISSN | 0018-9480 |
Abstract | In magnetic resonance imaging (MRI), wearable wireless receive coil arrays are a key technology goal. An MRI compatible wireless power transfer (WPT) system will be needed to realize this technology. An MRI WPT system must withstand the extreme electromagnetic environment of the scanner and cannot degrade MRI image quality. Here, a WPT system is developed for operation in MRI scanners using new microelectromechanical RF switch (RF MEMs) technology. The WPT system includes a class-E power amplifier, RF MEMs automated impedance matching, a primary coil array employing RF MEMs power steering, and a flexible secondary coil with class E rectification. To adapt WPT technology to MRI, techniques are developed for operation at high magnetic field, and to mitigate the RF interactions between the scanner and WPT system. A major challenge was the identification and suppression of noise and harmonic interference, by gating, filtering, and rectifier topologies. The system can achieve 63% efficiency while exceeding 13 W delivery over a coil distance of 3.5 cm. For continuous WPT beyond 5W, added filters and full-wave class E rectification lowers harmonic generation at some cost to efficiency, while image SNR reaches about 32% of the ideal. RF-gated WPT, which interrupts power transfer in the MRI signal acquisition interval, achieves SNR performance to within 1 dB of the ideal. With further refinement, the inclusion of WPT technology in MRI scanners appears completely feasible. |
DOI | 10.1109/TMTT.2019.2902554 |
Alternate Journal | IEEE Trans Microw Theory Tech |
PubMed ID | 31423023 |
PubMed Central ID | PMC6696940 |
Grant List | K99 EB024341 / EB / NIBIB NIH HHS / United States R00 EB024341 / EB / NIBIB NIH HHS / United States R01 EB009690 / EB / NIBIB NIH HHS / United States R01 EB019241 / EB / NIBIB NIH HHS / United States |
Related Institute:
MRI Research Institute (MRIRI)