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Medicine and Health Sciences

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Articles 151 - 163 of 163

Full-Text Articles in Systems and Integrative Physiology

Ultrasound Based Quantitative Motion Measurement Using Speckle Size Estimation, James D. Hamilton, Larry Y. L. Mo, Gregory R. Bashford Nov 2001

Ultrasound Based Quantitative Motion Measurement Using Speckle Size Estimation, James D. Hamilton, Larry Y. L. Mo, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

An ultrasound system determines the relative movement in a first direction (F1) of first matter, such as blood flow, and second matter, such as an artery wall, in a subject under study (S). A beam (B1) of ultrasound waves defining a plurality of beam positions (BP1 and BP2) and beam axes (A1 and A2) are moved in scan direction having components parallel to direction F1. First and second blocks of data representing the first and second matter, respectively, are generated. A processor (20) performs an estimation of speckle size on first data to obtain a first result, and performs analysis …


Method And Apparatus For Adaptive Filtering By Counting Acoustic Sample Zeroes In Ultrasound Imaging, Gregory R. Bashford, Edward D. Nonnweiler, David D. Becker, David John Muzilla Oct 2000

Method And Apparatus For Adaptive Filtering By Counting Acoustic Sample Zeroes In Ultrasound Imaging, Gregory R. Bashford, Edward D. Nonnweiler, David D. Becker, David John Muzilla

Biomedical Imaging and Biosignal Analysis Laboratory

An ultrasound imaging system having an adaptive spatial filter the filter coefficients of which, for particular image parameter sample, are determined by counting the number of neighboring image parameter samples having zero or near-zero values. If the number of zero or near-zero values in a data window is greater than a predetermined threshold, the data in the window is passed, not filtered. This filter has two advantages over other spatial filters. First, image parameter data samples having only zero or near-zero neighboring values (i.e., isolated "point noise") are not smeared. Second, boundaries such as the edge of color in a …


Method And Apparatus For Controlling Acoustic Signal Bandwidth In An Ultrasonic Diagnostic Imaging System, Jeffrey R. Resnick, Gregory R. Bashford Jun 2000

Method And Apparatus For Controlling Acoustic Signal Bandwidth In An Ultrasonic Diagnostic Imaging System, Jeffrey R. Resnick, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

An ultrasonic imaging system includes a receive beamformer that generates analog receive signals and a scan converter. A receive signal processing path interconnects the receive beamformer and the scan converter, and this processing path included both an A/D converter characterized by a selectable sampling rate and at least one filter characterized by at least one filter parameter. The filter parameter is selected as a function of the sampling rate to provide enhanced image quality.


Method And Apparatus For Three-Dimensional Ultrasound Imaging Of Biopsy Needle, Syed Omar Ishrak, Mir Said Seyed-Bolorforosh, William Thomas Hatfield, Todd Michael Tillman, Brian Peter Geiser, Gregory R. Bashford, Michael Joseph Washburn Apr 2000

Method And Apparatus For Three-Dimensional Ultrasound Imaging Of Biopsy Needle, Syed Omar Ishrak, Mir Said Seyed-Bolorforosh, William Thomas Hatfield, Todd Michael Tillman, Brian Peter Geiser, Gregory R. Bashford, Michael Joseph Washburn

Biomedical Imaging and Biosignal Analysis Laboratory

A method and an apparatus for three-dimensional ultrasound imaging of a needle-like instrument, such as a biopsy needle, inserted in a human body. The instrument is visualized by transmitting ultrasound beams toward the instrument and then detecting the echo signals using a linear array of transducer elements. The problem of ultrasound being reflected from a biopsy needle in a direction away from the transducer array is solved by steering the transmitted ultrasound beams t increase the angle at which the beams impinge upon the biopsy needle. Ideally the ultrasound beams are perpendicular to the needle. This increases the system's sensitivity …


Method And Apparatus For Controlling Acoustic Signal Bandwidth In An Ultrasonic Diagnostic Imaging System, Jeffrey R. Resnick, Gregory R. Bashford Nov 1999

Method And Apparatus For Controlling Acoustic Signal Bandwidth In An Ultrasonic Diagnostic Imaging System, Jeffrey R. Resnick, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

An ultrasonic imaging system includes a receive beam former that generates analog receive signals and a scan converter. A receive signal processing path interconnects the receive beamformer and the scan converter, and this processing path includes both an A/D converter characterized by a selectable sampling rate and at least one filter characterized by at least one filter parameter. The filter parameter is selected as a function of the sampling rate to provide enhanced image quality.


Lateral Hypothalamic Nmda Receptor Subunits Nr2a And/Or Nr2b Mediate Eating: Immunochemical/Behavioral Evidence, Arshad Khan, Margarita Curras, Jennifer Dao, Faizi Jamal, Rishi Goel, Elizabeth Gillard, Stefany Wolfsohn, B. Stanley Jan 1999

Lateral Hypothalamic Nmda Receptor Subunits Nr2a And/Or Nr2b Mediate Eating: Immunochemical/Behavioral Evidence, Arshad Khan, Margarita Curras, Jennifer Dao, Faizi Jamal, Rishi Goel, Elizabeth Gillard, Stefany Wolfsohn, B. Stanley

Selected Works Temporary Series

No abstract provided.


Lateral Hypothalamic Nmda Receptor Subunits Nr2a And/Or Nr2b Mediate Eating: Immunochemical/Behavioral Evidence, Khan, Margarita Curras, Jennifer Dao, Faizi Jamal, Rishi Goel, Elizabeth Gillard, Stefany Wolfsohn, B. Stanley Jan 1999

Lateral Hypothalamic Nmda Receptor Subunits Nr2a And/Or Nr2b Mediate Eating: Immunochemical/Behavioral Evidence, Khan, Margarita Curras, Jennifer Dao, Faizi Jamal, Rishi Goel, Elizabeth Gillard, Stefany Wolfsohn, B. Stanley

Departmental Papers (Biology)

No abstract provided.


The Second Messenger Camp Elicits Eating By An Anatomically Specific Action In The Perifornical Hypothalamus, Elizabeth Gillard, Arshad Khan, Rickinder Grewal, Bara Mouradi, Stefany Wolfsohn, B. Stanley Apr 1998

The Second Messenger Camp Elicits Eating By An Anatomically Specific Action In The Perifornical Hypothalamus, Elizabeth Gillard, Arshad Khan, Rickinder Grewal, Bara Mouradi, Stefany Wolfsohn, B. Stanley

Selected Works Temporary Series

No abstract provided.


The Second Messenger Camp Elicits Eating By An Anatomically Specific Action In The Perifornical Hypothalamus, Gillard, Arshad Khan, Rickinder Grewal, Bara Mouradi, Stefany Wolfsohn, B. Stanley Apr 1998

The Second Messenger Camp Elicits Eating By An Anatomically Specific Action In The Perifornical Hypothalamus, Gillard, Arshad Khan, Rickinder Grewal, Bara Mouradi, Stefany Wolfsohn, B. Stanley

Departmental Papers (Biology)

No abstract provided.


Eating Induced By Perifornical Camp Is Behaviorally Selective And Involves Protein Kinase Activity, Elizabeth Gillard, Arshad Khan, Bara Mouradi, Omkar Nalamwar, B. Stanley Jan 1998

Eating Induced By Perifornical Camp Is Behaviorally Selective And Involves Protein Kinase Activity, Elizabeth Gillard, Arshad Khan, Bara Mouradi, Omkar Nalamwar, B. Stanley

Selected Works Temporary Series

No abstract provided.


Eating Induced By Perifornical Camp Is Behaviorally Selective And Involves Protein Kinase Activity, Gillard, Arshad Khan, Bara Mouradi, Omkar Nalamwar, B. Stanley Jan 1998

Eating Induced By Perifornical Camp Is Behaviorally Selective And Involves Protein Kinase Activity, Gillard, Arshad Khan, Bara Mouradi, Omkar Nalamwar, B. Stanley

Departmental Papers (Biology)

No abstract provided.


Ultrasound Three- Dimensional Velocity Measurements By Feature Tracking, Gregory R. Bashford, Olaf T. Von Ramm May 1996

Ultrasound Three- Dimensional Velocity Measurements By Feature Tracking, Gregory R. Bashford, Olaf T. Von Ramm

Biomedical Imaging and Biosignal Analysis Laboratory

This article describes a new angle-independent method suitable for three-dimensional (3-D) blood flow velocity measurement that tracks features of the ultrasonic speckle produced by a pulse echo system. In this method, a feature is identified and followed over time to detect motion. Other blood flow velocity measurement methods typically estimate velocity using one- (1-D) or two-dimensional (2-D) spatial and time information. Speckle decorrelation due to motion in the elevation dimension may hinder this estimate of the true 3-D blood flow velocity vector. Feature tracking is a 3-D method with the ability to measure the true blood velocity vector rather than …


F Response Frequency For The Median And Ulnar Nerves In A Normal Population, Patricia J. Killea Aug 1992

F Response Frequency For The Median And Ulnar Nerves In A Normal Population, Patricia J. Killea

Rehabilitation Sciences Theses & Dissertations

The F wave or F response results form the recurrent discharge of antidromically activated anterior horn cells. F response latency represents an impulse which travels to and from the spinal cord through the central segment of a nerve. Study of the F wave is commonly done to assess proximal conduction in motor nerves, to measure motor nerve conduction velocity over a longer pathway than in orthodromic motor studies, and to assess motor neuron excitability. F response characteristics less commonly studied include duration, chronodispersion, shape, amplitude, and frequency. The primary purpose of this study was to determine F response frequencies of …