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HIGH FREQUENCY ULTRASONIC PHASED ARRAY SYSTEM AND ITS
APPLICATIONS
by
Fan Zheng
A Dissertation Presented to the
FACULTY OF THE USC GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(BIOMEDICAL ENGINEERING)
December 2012
Copyright 2012 Fan Zheng
Object Description
| Title | High frequency ultrasonic phased array system and its applications |
| Author | Zheng, Fan |
| Author email | fzheng@usc.edu;fanzheng@gmail.com |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Biomedical Engineering |
| School | Viterbi School of Engineering |
| Date defended/completed | 2012-09-14 |
| Date submitted | 2012-11-12 |
| Date approved | 2012-11-12 |
| Restricted until | 2012-11-12 |
| Date published | 2012-11-12 |
| Advisor (committee chair) | Shung, K. Kirk |
| Advisor (committee member) |
Yen, Jesse Kim, Eun Sok Zhou , Qifa |
| Abstract | While similar to a linear-switched array in structure, an ultrasound linear phased array (simply called phased array) is quite different in operation. It is capable of beam steering to form fan-shaped sector images without inducing grating lobes. Moreover, the relative smaller array footprint is useful where only very limited contact surface is permitted. High frequency phased arrays combine the advantages of the phased array and high frequency ultrasound, which offer both small footprint and high spatial resolution. This dissertation reports the design and development of a digital ultrasonic imaging platform with raw RF data acquisition capability, which can be paired with a prototype 64-element 26 MHz phased array transducer. A wire phantom image showed that -6 dB lateral and axial resolutions were 209 and 104 μm, respectively, which were in good agreement with the Field II simulation. Anechoic cyst tissue-mimicking phantom images demonstrated its capability to detect cysts of 300 μm in diameter. An image of a rabbit eyeball in vitro was also acquired. This imaging platform is designed for the purpose of testing high frequency phased arrays under development as well as facilitating the development in novel array signal processing algorithms. ❧ Without additional change in the system hardware, the current high frequency array system can be also applied in the industrial non-destructive testing (NDT) applications. A motorized XY stage allows the array system to acquire C-mode scan as well as normal B-mode scan with bigger scanning area. Electronic scanning in array system could dramatically reduce the total scanning time compare to single element system. An aluminum sample and a silicon carbide sample were examined to test the system in non-destructive testing. ❧ Besides the applications in biomedical imaging and non-destructive testing, the high frequency ultrasonic phased array and system are shown to be capable of trapping and translating microparticles precisely and efficiently, made possible due to the fact that the acoustic beam produced by a phased array can be both focused and steered. Acoustic manipulation of microparticles by a phased array is advantageous over a single element transducer since there is no mechanical movement required for the array. Experimental results show that 45 μm diameter polystyrene microspheres can be easily and accurately trapped and moved to desired positions by a 64-element 26 MHz phased array. |
| Keyword | high frequency; ultrasound; phased array; imaging system |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m |
| Rights | Zheng, Fan |
| Access conditions | The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the author, as the original true and official version of the work, but does not grant the reader permission to use the work if the desired use is covered by copyright. It is the author, as rights holder, who must provide use permission if such use is covered by copyright. The original signature page accompanying the original submission of the work to the USC Libraries is retained by the USC Libraries and a copy of it may be obtained by authorized requesters contacting the repository e-mail address given. |
| Repository name | University of Southern California Digital Library |
| Repository address | USC Digital Library, University of Southern California, University Park Campus MC 7002, 106 University Village, Los Angeles, California 90089-7002, USA |
| Repository email | cisadmin@usc.edu |
| Archival file | uscthesesreloadpub_Volume4/etd-ZhengFan-1284.pdf |
Description
| Title | Page 1 |
| Full text | HIGH FREQUENCY ULTRASONIC PHASED ARRAY SYSTEM AND ITS APPLICATIONS by Fan Zheng A Dissertation Presented to the FACULTY OF THE USC GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (BIOMEDICAL ENGINEERING) December 2012 Copyright 2012 Fan Zheng |
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