TY - JOUR
T1 - A Study on Ultrasonic Wireless Power Transfer With Phased Array for Biomedical Implants
AU - Kashani, Zeinab
AU - Kiani, Mehdi
N1 - Publisher Copyright:
© 2007-2012 IEEE.
PY - 2023/8/1
Y1 - 2023/8/1
N2 - This article presents the design, fabrication, and sensitivity analysis of an ultrasound (US) wireless power transfer (WPT) link using an external phased array. Optimal beam focusing and steering is needed for efficient, safe, and reliable US WPT to biomedical implants with millimeter (mm) dimensions. Therefore, the main contributions of this work include the investigation of the 1) performance of the US WPT link using different mm-sized US receivers, 2) effect of different types of errors in the delay profile of the beamforming system on the delivered power, and 3) implant's localization. In measurements, the fabricated 0.94 MHz, 32-element array (39.48 × 9.6 × 2 mm3) driven by 25 V pulses with beam focusing and steering capability up to 50 mm depth and ±60o angle could deliver power to different mm-sized US receivers within the FDA safety limit of 720 mW/cm2. Specifically, several US transducers with a 1 mm dimension (sphere, cubic, disc shape) and 2 mm dimension (disc shape) received 0.095 mW, 0.25 mW, 0.22 mW, and 0.53 mW, respectively, at a 30 mm depth (0o steering angle). Among these transducers, the sphere shape transducer featured less sensitivity to misalignments. A random error in the phased array delays had a more drastic effect on delivered power reduction. For implant's localization, the measurement results demonstrated comparable power delivery by measuring pulse delays of only 5 elements (out of 32 elements) using 4 different interpolation methods.
AB - This article presents the design, fabrication, and sensitivity analysis of an ultrasound (US) wireless power transfer (WPT) link using an external phased array. Optimal beam focusing and steering is needed for efficient, safe, and reliable US WPT to biomedical implants with millimeter (mm) dimensions. Therefore, the main contributions of this work include the investigation of the 1) performance of the US WPT link using different mm-sized US receivers, 2) effect of different types of errors in the delay profile of the beamforming system on the delivered power, and 3) implant's localization. In measurements, the fabricated 0.94 MHz, 32-element array (39.48 × 9.6 × 2 mm3) driven by 25 V pulses with beam focusing and steering capability up to 50 mm depth and ±60o angle could deliver power to different mm-sized US receivers within the FDA safety limit of 720 mW/cm2. Specifically, several US transducers with a 1 mm dimension (sphere, cubic, disc shape) and 2 mm dimension (disc shape) received 0.095 mW, 0.25 mW, 0.22 mW, and 0.53 mW, respectively, at a 30 mm depth (0o steering angle). Among these transducers, the sphere shape transducer featured less sensitivity to misalignments. A random error in the phased array delays had a more drastic effect on delivered power reduction. For implant's localization, the measurement results demonstrated comparable power delivery by measuring pulse delays of only 5 elements (out of 32 elements) using 4 different interpolation methods.
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U2 - 10.1109/TBCAS.2023.3282197
DO - 10.1109/TBCAS.2023.3282197
M3 - Article
C2 - 37267144
AN - SCOPUS:85161003010
SN - 1932-4545
VL - 17
SP - 713
EP - 724
JO - IEEE transactions on biomedical circuits and systems
JF - IEEE transactions on biomedical circuits and systems
IS - 4
ER -