ECE Master of Science Thesis Defense By: Jawanza Foster
When: Friday,
April 10, 2020
10:00 AM
-
12:00 PM
Where: > See description for location
Cost: free
Description: Topic: Challenges in Designing a Waveguide to Transmit Sound to a Dolphin in an MRI
Zoom Teleconference: https://umassd.zoom.us/j/881626521
Abstract:
Functional Magnetic Resonance Imaging (fMRI) offers great opportunities to learn how a dolphin's brain processes acoustic echolocation and communication signals. Delivering sound to an animal in a fMRI requires a sound delivery system with no ferrous metal. This thesis proposes an approach that generates sound far from the fMRI magnet, then propagates the sound through a waveguide to the dolphin roughly 10 meters away. The waveguide needs to function at two frequency ranges for echolocation signals (80kHz) and communication signals (10kHz to 20kHz). This approach has two challenges: will there be enough energy for the dolphin to hear the acoustic signals, and will the received signal be distorted? The waveguide attenuates energy due to absorption and friction. The impedance mismatch between the boundary of waveguide and the dolphin also loses energy. Filling the waveguide with water limits the transmission loss through the waveguide but causes the waveguide's radial boundary condition to be pressure release. When the radial boundary is pressure release, all modes trapped in the waveguide will have dispersion. Distortion due to dispersion will be minimized through equalization.
Note: All ECE Graduate Students are ENCOURAGED to join the zoom teleconference.
All interested parties are invited to join.
Advisor: Dr. John R. Buck
Committee Members: Dr. David A. Brown and Dr. Karen L. Payton, Department of Electrical & Computer Engineering, UMASS Dartmouth
*For further information, please contact Dr. John R. Buck at 508.999.9237, or via email at jbuck@umassd.edu.
Zoom Teleconference: https://umassd.zoom.us/j/881626521
Abstract:
Functional Magnetic Resonance Imaging (fMRI) offers great opportunities to learn how a dolphin's brain processes acoustic echolocation and communication signals. Delivering sound to an animal in a fMRI requires a sound delivery system with no ferrous metal. This thesis proposes an approach that generates sound far from the fMRI magnet, then propagates the sound through a waveguide to the dolphin roughly 10 meters away. The waveguide needs to function at two frequency ranges for echolocation signals (80kHz) and communication signals (10kHz to 20kHz). This approach has two challenges: will there be enough energy for the dolphin to hear the acoustic signals, and will the received signal be distorted? The waveguide attenuates energy due to absorption and friction. The impedance mismatch between the boundary of waveguide and the dolphin also loses energy. Filling the waveguide with water limits the transmission loss through the waveguide but causes the waveguide's radial boundary condition to be pressure release. When the radial boundary is pressure release, all modes trapped in the waveguide will have dispersion. Distortion due to dispersion will be minimized through equalization.
Note: All ECE Graduate Students are ENCOURAGED to join the zoom teleconference.
All interested parties are invited to join.
Advisor: Dr. John R. Buck
Committee Members: Dr. David A. Brown and Dr. Karen L. Payton, Department of Electrical & Computer Engineering, UMASS Dartmouth
*For further information, please contact Dr. John R. Buck at 508.999.9237, or via email at jbuck@umassd.edu.
Contact:
ECE: Electrical & Computer Engineering Department 508.999.9164 http://www.umassd.edu/engineering/ece/
Topical Areas: General Public, University Community, College of Engineering, Electrical and Computer Engineering