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Reza Erfani_PhD Dissertation.pdf (8.25 MB)

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Capacitive Wireless Power Transfer to Biomedical Implants: Link Design, Implementation, and Related Power Management Integrated Circuitry

Erfani, Reza
http://orcid.org/0000-0001-8165-1478
http://rave.ohiolink.edu/etdc/view?acc_num=case1595442132614016

Abstract Details

2020, Doctor of Philosophy, Case Western Reserve University, EECS - Electrical Engineering.
Methodologies for wireless power transfer (WPT) to implantable medical devices (IMDs) as an attractive solution toward obviating the need for primary battery have continuously evolved over the past decades. Capacitive WPT (C–WPT) is an emerging methodology that offers a higher dynamic range in power delivery when coping with biosafety limits as compared to its ultrasonic and inductive counterparts and introduces a unique advantage of flexible implementation with minimal costs on important link parameters. The C–WPT has been under investigation for delivering moderate-to-high levels of wireless power to centimeter-sized IMDs with an implantation depth of a few millimeters and thus suitable for IMDs in peripheral/autonomic applications. This work, for the first time, presents design and implementation of a complete C–WPT system for subcutaneously-implanted IMDs. That is a multidisciplinary research work involving co-design and co-development of capacitive link across a tissue layer and circuits/systems interfacing with the link on both external and implant sides including CMOS power management integrated circuits (PMICs) that interfaces with capacitive link on the implant side and performs efficient AC-to-DC conversion. One part of this work is focused on modeling, characterization, and development of a bio-safe capacitive link across tissue for C–WPT where an accurate circuit model for capacitive elements is proposed followed by a comprehensive circuit model for a series-resonant capacitive link setup. Electromagnetic simulations via ANSYS HFSS provide further insights into the capacitive link behavior and investigates the biosafety levels of the link. Flexible and conformal implementation of capacitive link on copper substrates is shown for ease of implantation. Following the link characterization, different PMIC designs are shown for capacitively-powered IMDs. First, a frequency-aware CMOS active rectifier IC with dual-loop adaptive delay compensation and >230mW output power is proposed that features power conversion efficiency (PCE) of >84.4% (peak of 91.5%) when operating in 1–10 MHz and driving a load of 300Ω. The active rectifier IC is interfaced with an actual series-resonant capacitive link formed by coated flexible plates around a 3mm-thick tissue demonstrating an end-to-end power transfer efficiency of >40% between 2–10 MHz. Following that, a reconfigurable dual-output regulating rectifier IC is presented for efficient, single-stage AC to regulated-DC conversion on the implant side that provides two independently-regulated supply voltages (each between 1.5–3V). Fabricated in 0.18μm 1P/6M CMOS, PCE of >83.8% was measured at 2 and 5MHz when simultaneously providing two supply voltages of 1.5V and 2.5V. The dual-output regulating rectifier IC is also interfaced with an actual series-resonant capacitive link formed with coated flexible plates around a 3mm-thick tissue and wirelessly powered up a PPG readout IC requiring two supply voltages of 1.5V and 2.5V.
Pedram Mohseni (Advisor)
Hossein Miri Lavasani (Committee Member)
Farncis Merat (Committee Member)
Kevin Kilgore (Committee Member)
214 p.
Biomedical Engineering; Biomedical Research; Design; Electrical Engineering; Electromagnetics; Energy; Engineering; Health Care
Biomedical implants; transcutaneous wireless power transfer; wireless powering; capacitive wireless power transfer; capacitive link; biosafety; power management integrated circuit; PMIC; CMOS active rectifier IC; CMOS dual-output regulating rectifier IC

Recommended Citations

Citations

  • Erfani, R. (2020). Capacitive Wireless Power Transfer to Biomedical Implants: Link Design, Implementation, and Related Power Management Integrated Circuitry [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1595442132614016

    APA Style (7th edition)

  • Erfani, Reza. Capacitive Wireless Power Transfer to Biomedical Implants: Link Design, Implementation, and Related Power Management Integrated Circuitry . 2020. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1595442132614016.

    MLA Style (8th edition)

  • Erfani, Reza. "Capacitive Wireless Power Transfer to Biomedical Implants: Link Design, Implementation, and Related Power Management Integrated Circuitry ." Doctoral dissertation, Case Western Reserve University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1595442132614016

    Chicago Manual of Style (17th edition)

case1595442132614016
230
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This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.