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Charles G. Sodini and Hae-Seung Lee. Pietrangelo, Sabino Joseph Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science. Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science 2017-05-11T19:06:45Z 2017-05-11T19:06:45Z 2017 2017 http://hdl.handle.net/1721.1/108848 986522024 Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. Cataloged from student-submitted PDF version of thesis. Includes bibliographical references (pages 183-190). Transcranial Doppler (TCD) sonography is a specialized ultrasound technique that enables measurement of blood ow velocity from the basal intracerebral vessels. Use of TCD sonography is highly compelling as a diagnostic modality due to its safety in prolonged studies, high temporal resolution, and relative portability. Although TCD methods have been clinically indicated in a variety of cerebrovascular diagnostic applications, general acceptance by the medical community has been impeded by several critical deficiencies { including the need for a highly-trained TCD operator, operator dependent measurement results, and severe patient movement restrictions. This thesis seeks to mitigate such limitations through the development of a compact, wearable TCD ultrasound system, permitting untethered cerebrovascular monitoring with limited operator interaction. The prototype system incorporates a custom two-dimensional transducer array and multi-channel transceiver electronics, thereby facilitating acoustic focusing via phased array operation. Algorithmic vessel search and tracking further reduce operator dependencies by expediting vessel localization, systematizing vessel identification, and dynamically adapting to relative vessel position. Additionally, focal correction methods are presented, which improve acoustic beamformation capabilities in the presence of tissue inhomogeneities. Validation of the prototype hardware and embedded signal processing implementations under flow phantom and human subject testing yields high correlation with accepted velocimetry methods. Vessel search and tracking functionality are also verified experimentally. Circuit integration is explored to further reduce instrumentation dimensions and power consumption. by Sabino Joseph Pietrangelo. Ph.D. 190 pages eng Massachusetts Institute of Technology MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission. http://dspace.mit.edu/handle/1721.1/7582 Electrical Engineering and Computer Science. A wearable Transcranial Doppler ultrasound phased array system Wearable TCD ultrasound phased array system Thesis application/pdf Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="75cdbb37-0b4a-405b-9996-a42c4c3c6162"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>A wearable Transcranial Doppler ultrasound phased array system</Title> <Subtitle>Wearable TCD ultrasound phased array system</Subtitle> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2017</PublicationDate> <Authors> <Author> <DisplayName>Pietrangelo, Sabino Joseph</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Electrical Engineering and Computer Science.</Keyword> <Abstract>Transcranial Doppler (TCD) sonography is a specialized ultrasound technique that enables measurement of blood ow velocity from the basal intracerebral vessels. Use of TCD sonography is highly compelling as a diagnostic modality due to its safety in prolonged studies, high temporal resolution, and relative portability. Although TCD methods have been clinically indicated in a variety of cerebrovascular diagnostic applications, general acceptance by the medical community has been impeded by several critical deficiencies { including the need for a highly-trained TCD operator, operator dependent measurement results, and severe patient movement restrictions. This thesis seeks to mitigate such limitations through the development of a compact, wearable TCD ultrasound system, permitting untethered cerebrovascular monitoring with limited operator interaction. The prototype system incorporates a custom two-dimensional transducer array and multi-channel transceiver electronics, thereby facilitating acoustic focusing via phased array operation. Algorithmic vessel search and tracking further reduce operator dependencies by expediting vessel localization, systematizing vessel identification, and dynamically adapting to relative vessel position. Additionally, focal correction methods are presented, which improve acoustic beamformation capabilities in the presence of tissue inhomogeneities. Validation of the prototype hardware and embedded signal processing implementations under flow phantom and human subject testing yields high correlation with accepted velocimetry methods. Vessel search and tracking functionality are also verified experimentally. Circuit integration is explored to further reduce instrumentation dimensions and power consumption.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>