자료유형 | 학위논문 |
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서명/저자사항 | Dual-band Power and Communication Antennas for Wireless Brain-computer Interfaces. |
개인저자 | Sharma, Apoorva. |
단체저자명 | University of Washington. Electrical and Computer Engineering. |
발행사항 | [S.l.]: University of Washington., 2019. |
발행사항 | Ann Arbor: ProQuest Dissertations & Theses, 2019. |
형태사항 | 150 p. |
기본자료 저록 | Dissertations Abstracts International 81-03B. Dissertation Abstract International |
ISBN | 9781085748322 |
학위논문주기 | Thesis (Ph.D.)--University of Washington, 2019. |
일반주기 |
Source: Dissertations Abstracts International, Volume: 81-03, Section: B.
Advisor: Reynolds, Matthew S. |
이용제한사항 | This item must not be sold to any third party vendors.This item must not be added to any third party search indexes. |
요약 | Implanted biomedical devices such as wireless brain-computer interfaces (BCIs) for neural recording and stimulation face two key challenges: (1) remaining powered over a long duration and (2) communicating with an external system with sufficient bandwidth in an unconstrained environment without data dropouts. A viable solution to solve these problems is to supply power to the BCI device via inductive coupling at the high-frequency (HF) band (13.5 MHz) and to have data communication at the ultrahigh-frequency (UHF) band (902-928 MHz). To fulfill these requirements, design of dual-band (HF and UHF) antennas for BCI and external devices are needed. Designing HF and UHF antennas together in a small printed circuit board (PCB) size (area of approx. 0.002 m2) is a challenging task due to (1) the relatively long wavelengths of HF (approx. 22 m) and UHF bands (approx. 0.3 m), (2) the desire to minimize the specific absorption rate (SAR), (3) the wide bandwidth required in the communication band, and (4) the need to minimize unwanted interference between the power and communication systems.This thesis presents two BCI antenna systems: (1) a novel electrically-small dual-band implant antenna (27 mm diameter) to be embedded in the dura layer (approx. 1 cm below the skin's surface) with an external antenna (85 mm diameter) in proximity (few millimeters) to the skin's surface, and (2) a dual-band BCI antenna (55mmdiameter) designed to be installed on the top of non-human primate's (NHP) head, with an external antenna located inside the top wall of the housing cage. The antennas were tested initially using a saline tissue proxy. Later, the implant antenna was tested inside the chicken muscle. With an implant depth of 11 mm and an air gap of 5mm, the power link has a 17 % measured power transfer efficiency in the HF band, inclusive of matching component losses, and the UHF communication link has 38 dB insertion loss over the 902-928 MHz band using saline solution. In chicken muscle UHF communication link has 7.5 dB lower insertion loss as compared to saline solution. Head-stage antennas designed for large NHPs were tested inside a metal housing cage. Wireless communication inside the cage is a challenging task as the metal walls form a reverberating cavity, creating dense multipath, resulting in many deep nulls that impair the communication channel. Later in the thesis, in-vivo recordings were performed on an anesthetized pigtail macaque (Macaca nemestrina), to validate the performance of wireless backscatter uplinks. The monostatic backscatter data uplink using ceramic BCI antenna, designed for NHPs, was successfully validated inside the cage, exhibiting 0 % packet error ratio (PER) for 23 of 25 measurement location points, at a data rate of 6.25 Mbps, and PER greater than 5 % at two measurement location points due to the presence of deep nulls inside the cage. These experimental results showed high data rate communication with low PER, in the presence of significant multipath. In this work, the highest data rate achieved to uplink the recorded neural signals of an anesthetized pigtail macaque to the external system from the proposed head-stage antenna system is 25 Mbps.The success of the antenna designs presented in this thesis open an opportunity to utilize wireless BCI systems in the future for human clinical applications (for example, in neural-recording and deep-brain stimulation for people with Parkinson's disease and other neurological disorders), and for neuroscience research on awake, freely moving animals. |
일반주제명 | Electrical engineering. Electromagnetics. Biomedical engineering. |
언어 | 영어 |
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