Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 8 of 8
Full-Text Articles in Engineering
Acoustic Radiation Force And Its Application For Cell Manipulation And Ion Channels Activation, Xiangjun Peng
Acoustic Radiation Force And Its Application For Cell Manipulation And Ion Channels Activation, Xiangjun Peng
McKelvey School of Engineering Theses & Dissertations
Sound is a stress wave that carries energy and momentum flux. Scattered sound waves can generate acoustic radiation force that can be used to manipulate particles or cells. This dissertation demonstrates the physics behind cell manipulation by ultrasound. The work begins with a detailed analysis of the mechanics of using standing surface acoustic waves to fabricate acoustic tweezers for contactless particle manipulation using acoustic radiation force. Models to design and analyze acoustic radiation force have traditionally relied on plane wave theories that cannot predict how standing surface acoustic waves can levitate cells in the direction perpendicular to the substrate. We …
Photoacoustic Imaging Of Colorectal Cancer And Ovarian Cancer, Xiandong Leng
Photoacoustic Imaging Of Colorectal Cancer And Ovarian Cancer, Xiandong Leng
McKelvey School of Engineering Theses & Dissertations
Photoacoustic (PA) imaging is an emerging hybrid imaging technology that uses a short-pulsed laser to excite tissue. The resulting photoacoustic waves are used to image the optical absorption distribution of the tissue, which is directly related to micro-vessel networks and thus to tumor angiogenesis, a key process in tumor growth and metastasis. In this thesis, the acoustic-resolution photoacoustic microscopy (AR-PAM) was first investigated on its role in human colorectal tissue imaging, and the optical-resolution photoacoustic microscopy (OR-PAM) was investigated on its role in human ovarian tissue imaging.Colorectal cancer is the second leading cause of cancer death in the United States. …
Indoor Positioning Using Synchronized Ultrasonic Ofdma Signals, Julian Bartolone
Indoor Positioning Using Synchronized Ultrasonic Ofdma Signals, Julian Bartolone
Master's Theses
This paper proposes a method of short-range indoor localization using differential phase measurements of synchronized two-tone ultrasonic signals in an Orthogonal Frequency Multiple Access (OFDMA) scheme. This indoor positioning system (IPS) operates at an ultrasonic frequency of approximately 40kHz and synchronizes using an infrared signal. The OFDMA scheme allows for a receiver to process the signals from multiple transmitters continuously without the signals interfering with each other. The phases of the signals are measured using Goertzel Filters, allowing for low-complexity frequency content analysis. A MATLAB simulation using the proposed localization method is performed using four transmitter nodes in the corners …
Mixed-Reality Visualization Environments To Facilitate Ultrasound-Guided Vascular Access, Leah Groves
Mixed-Reality Visualization Environments To Facilitate Ultrasound-Guided Vascular Access, Leah Groves
Electronic Thesis and Dissertation Repository
Ultrasound-guided needle insertions at the site of the internal jugular vein (IJV) are routinely performed to access the central venous system. Ultrasound-guided insertions maintain high rates of carotid artery puncture, as clinicians rely on 2D information to perform a 3D procedure. The limitations of 2D ultrasound-guidance motivated the research question: “Do 3D ultrasound-based environments improve IJV needle insertion accuracy”. We addressed this by developing advanced surgical navigation systems based on tracked surgical tools and ultrasound with various visualizations. The point-to-line ultrasound calibration enables the use of tracked ultrasound. We automated the fiducial localization required for this calibration method such that …
Unsupervised Data Driven Machine Learning In Hyperspectral Imaging And Echocardiography Videos, Kazi Tanzeem Shahid
Unsupervised Data Driven Machine Learning In Hyperspectral Imaging And Echocardiography Videos, Kazi Tanzeem Shahid
Electrical Engineering Dissertations
This work discusses the problem of unsupervised classification in images. Conventional methods approached this problem with the naive assumption that the relationship among the pixels' information can be expressed sufficiently in a linear manner. However, higher accuracy was established by implementing kernel-based expressions of data to express the non-linear relationship of that data in a linear manner, when mapped in a higher dimensional space. This process allows much more effective clustering performances by increasing the informativeness of the data. Hyperspectral images, being limited in spatial resolution as a tradeoff for the significantly higher number of channels compared to traditional images, …
Performance Of Ultrasound-Assisted Forward Osmosis Membrane Process In Desalination Of Seawater, Bara Awwad Al-Sakaji
Performance Of Ultrasound-Assisted Forward Osmosis Membrane Process In Desalination Of Seawater, Bara Awwad Al-Sakaji
Theses
The objective of this study was to investigate the effect of using ultrasound on water flux through forward osmosis membrane when applied for seawater desalination. A synthetically prepared solution simulating seawater characteristics was used. Parameters considered in the investigation included membrane cross-flow velocity (0.25 and 1.0 cm/s), flow configuration (co-current versus counter-current), direction of ultrasound waves relative to the membrane side (active layer versus support layer), and type of draw solution (NaCl versus MgCl2). Furthermore, a two-level factorial design was considered in the analysis of the results obtained from the experimental work. This study revealed that applying a …
Experimental Investigation Of The Effects Of Acoustic Waves On Natural Convection Heat Transfer From A Horizontal Cylinder In Air, Katherina V. Prodanov
Experimental Investigation Of The Effects Of Acoustic Waves On Natural Convection Heat Transfer From A Horizontal Cylinder In Air, Katherina V. Prodanov
Master's Theses
Heat transfer is a critical part of engineering design, from the cooling of rocket engines to the thermal management of the increasingly dense packaging of electronic circuits. Even for the most fundamental modes of heat transfer, a topic of research is devoted to finding novel ways to improve it. In recent decades, investigators experimented with the idea of exposing systems to acoustic waves with the hope of enhancing thermal transfer at the surface of a body. Ultrasound has been applied with some success to systems undergoing nucleate boiling and in single-phase forced and free convection heat transfer in water. However, …
Multiparametric Quantitative Acoustic Imaging Of Cervical Remodeling During Pregnancy, Yan Yan
Multiparametric Quantitative Acoustic Imaging Of Cervical Remodeling During Pregnancy, Yan Yan
Wayne State University Dissertations
The uterine cervix plays a central role in the maintenance of pregnancy and the process of parturition. Untimely cervical ripening in early gestation predisposes to preterm labor and delivery, the leading cause of infant mortality worldwide. The current approach to evaluate the status of the cervix relies on digital and sonographic examination, which indicates the morphological changes of the cervix (cervical length). Therefore, assessing cervix tissue composition changes may provide more sensitive evaluations about cervix status beyond cervical length. Photoacoustic (PA) imaging is a relatively new, non-invasive ultrasound (US) based technology that captures acoustic signals emitted by tissue components in …