Download or read book Ultrasonic Wireless Power and Data Transmission to Miniaturized Biomedical Implants Using Phased Array written by Zeinab Kashani and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD dissertation focuses on developing efficient ultrasonic (US) wireless power and data transfer technologies for biomedical implants with millimeter (mm) dimensions. An ultrasonically interrogated (power/data) system with an external US array for beam focusing and steering through US beamforming is proposed to enable gastric electrical-wave mapping for diagnosing and eventually treating gastrointestinal motility disorders. The dissertation is divided into five parts. In the first part, the theory, design, and characterization of a wireless power transfer (WPT) link using mm-sized receivers (Rx) and a phased array (as external transmitter) are discussed. For given constraints imposed by the application and fabrication, such as the load (RL) and focal/powering distance (F), the optimal geometries of a US phased array and Rx transducer, as well as the optimal operation frequency (fc) are found through an iterative design procedure to maximize the power transfer efficiency (PTE). An optimal figure of merit (FoM) related to the link's PTE is proposed to simplify the US array design. In measurements, a fabricated 16-element array driven by 100 V pulses at an optimal frequency generated a US beam with a pressure output of 0.8 MPa and delivered up to 6 mW to a 1 mm3 Rx with a PTE of 0.14%. In the second part of this dissertation, a comprehensive study of wireless power transmission using a 32-element phased array capable of beam focusing and steering up to 50 mm depth and ±60o angle is provided. The performance of the US WPT link using mm-sized US receivers with different geometries and dimensions, the effect of different types of errors in the delay profile of the beamforming system on the delivered power, and the feasibility and efficacy of implant's localization with pulse-delay measurements with limited number of elements are investigated. The WPT link performance is evaluated based on the delivered power (within FDA safety limits) to mm-sized receivers with different geometries and diameters. In the third part of this dissertation, optimal US pulse transmission is demonstrated that could be used for data transmission to/from millimeter-sized biomedical implants in general or the self-image-guided ultrasonic (SIG-US) WPT. In SIG-US WPT, short pulses are transmitted by the implant periodically. The relative delays in the received signal by each external transducer in an array are then used to guide the beamformer for optimal steering of the power beam towards the implant. The effect of number of transmitted pulses on the iv amplitude of the received signal is studied, which is vital for low-power robust transmission. Furthermore, an adaptive application-specific integrated circuit (ASIC) for closed-loop low-power (and robust) US pulse-based data transmission is presented. The number of transmitted US pulses is changed based on the received voltage at the external unit in the closed-loop system to improve robustness and minimize the power consumption of the data transmitter. The ASIC, designed and fabricated in a 0.35[mu]m standard CMOS process, includes power management, controller/pulse driver, and envelope detector units. The fourth part of this dissertation includes ASIC design for low-frequency, low-power, and low-noise amplifiers that will be used to record gastric slow-wave signals. Simulation results and some limited measurement results are provided. The fifth part of this dissertation includes measurement results for a dual-mode ultrasonic- magnetic approach for wireless power transmission and energy harvesting. This dual-mode approach has the potential to solve the problem of power reduction when implant is rotating and to deliver high power within FDA safety limit using two different modalities. The future steps for circuit/system design, development, and testing are outlined. This dissertation represents an important step towards an implantable fully wireless gastric system, interrogated with a dual-mode ultrasonic-magnetic link for wireless power/data transfer, which can have a broad impact in the fields of health monitoring, diagnosis, and therapy.