high-performance integrated circuits for ultrasound neuromodulation and power management of medical implants
Open Access
- Author:
- Sadeghi Gougheri, Hesam
- Graduate Program:
- Electrical Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- March 02, 2020
- Committee Members:
- Mehdi Kiani, Dissertation Advisor/Co-Advisor
Mehdi Kiani, Committee Chair/Co-Chair
Ram Mohan Narayanan, Committee Member
Seyedehaida Ebrahimi, Committee Member
Bruce Gluckman, Outside Member
Kultegin Aydin, Program Head/Chair - Keywords:
- ultrasound neuromodulation
inductive power transmission
power management - Abstract:
- In general, this Ph.D. thesis aims at developing innovative technologies for interfacing with the central and peripheral nervous systems. More particularly, this thesis is focused on the design, development, and testing of novel circuits and systems for ultrasound neuromodulation and power management of those implantable medical devices (IMDs) which are powered by wireless power transmission (WPT) via inductive coupling. First, a new class of integrated power management (IPM) application-specific integrated circuits (ASICs) is proposed for efficient, robust, and long-range inductive power transmission. Unlike conventional IPM ASICs with voltage-mode (VM) operation, a current-mode (CM) IPM structure is proposed in which the receiver coil is employed as a current source. Several features have been added to the CM IPM structure to noticeably improve performance of the wireless IMDs in terms of voltage regulation, maximum provided output power, and lifetime. In the second part, the concept of microscopic ultrasound stimulation (μUS) is proposed in which either an electronically phased array of ultrasound transducers or several millimeter-sized focused transducers can directly be placed on the brain surface with partially removed skull (or over thinned skull) to deliver a focused ultrasound pressure to the neural target. A comprehensive study of ultrasound transducer characterization is presented to find optimal design of the transducers for μUS application. An ultrasound neuromodulation ASIC is designed and fabricated to drive the transducer with sufficient power, and finally a couple of preliminary animal experiments with commercial off-the-shelf (COTS) components are carried out. In chapter 1 of this dissertation, the proposed technologies for ultrasound neuromodulation and power management of IMDs are briefly introduced, and an overview over current technologies for neuromodulation and WPT to IMDs is presented. Also, the main contributions of this thesis are briefly described. In chapter 2, a current-based resonant power delivery (CRPD) technique is presented for extended-range WPT. In chapter 3, a self-regulated reconfigurable voltage/current-mode integrated power management (VCIPM) is presented for robust inductive WPT. In chapter 4, optimal wireless receiver structure for omnidirectional WPT is discussed. A self-regulated seamless-voltage/current-mode IPM with energy recycling capability is presented in chapter 5. To improve maximum output power provided to IMDs, a dual-output reconfigurable shared-inductor boost-converter/current-mode IPM is presented in chapter 6. In chapter 7, a comprehensive study of ultrasound transducer characteristics in μUS is presented. An ASIC for ultrasound neuromodulation is proposed in chapter 8. Finally, in chapter 9 preliminary animal experiments and future works are discussed. This research has resulted so far in 6 journal papers, 8 peer-reviewed conference papers, 1 pending US patent, and 1 book chapter.