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Biomedical Engineering and Bioengineering Commons

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Full-Text Articles in Biomedical Engineering and Bioengineering

Pre-Amplifiers For A 15-Tesla Magnetic Resonance Imager, Chin-Leong Lim, Peter Serano, Jerome L. Ackerman Nov 2013

Pre-Amplifiers For A 15-Tesla Magnetic Resonance Imager, Chin-Leong Lim, Peter Serano, Jerome L. Ackerman

Chin-Leong Lim

High-field magnetic resonance imagers (MRI) give better signal-to-noise ratio (SNR) and image contrast. However clinical MRIs are currently limited to 3 Tesla (T) magnetic field strength. To create an uncommon 15 T scanner for research use, we evaluated several low-cost, intended for wireless communication, GaAs enhancement-mode pseudomorphic high electron mobility transistors (ePHEMT) in the critical preamplifier slot. This paper reports the experimental results that were obtained at both module and system levels. When evaluated in our prototype 15 T scanner front-end’s preamplifier slot, the candidate devices’ sub 1dB noise figures enabled image SNR ~ 110 in a water phantom (test …


Footwear-Centric Body Area Network With Directional Uwb Antenna, Domenico Gaetano, Vit Sipal, Patrick Mcevoy, Max Ammann, C Brannigan, Louise Keating, Frances Horgan Jul 2013

Footwear-Centric Body Area Network With Directional Uwb Antenna, Domenico Gaetano, Vit Sipal, Patrick Mcevoy, Max Ammann, C Brannigan, Louise Keating, Frances Horgan

Articles

A footwear-centric body area network employing a directional antenna is compared with waist-centric systems using omnidirectional and directional antennas. The impact of body movements on path gain is analysed for two bands at 3.99 GHz and 7.99 GHz. The path gain and data rate results demonstrate that footwear-centric configurations are equivalent or better than waist-centric body area networks.


Comparison Of Non-Coherent Linear Breast Cancer Detection Algorithms Applied To A 2-D Numerical Breast Model, Giuseppe Ruvio, Raffaele Solimene, Antonio Cuccaro, Max Ammann Jan 2013

Comparison Of Non-Coherent Linear Breast Cancer Detection Algorithms Applied To A 2-D Numerical Breast Model, Giuseppe Ruvio, Raffaele Solimene, Antonio Cuccaro, Max Ammann

Articles

A comparative analysis of an imaging method based on a multi-frequency Multiple Signal Classification (MUSIC) approach against two common linear detection algorithms based on non-coherent migration is made. The different techniques are tested using synthetic data generated through CST Microwave Studio and a phantom developed from MRI scans of a mostly fat breast. The multi-frequency MUSIC approach shows an overall superior performance compared to the non-coherent techniques. This paper reports that this highly performing algorithm does not require any antenna calibration or phase response estimation and allows the use of efficient and complex antenna geometries without difficult algorithm redefinitions.


Independent Component Analysis Enhancements For Source Separation In Immersive Audio Environments, Yue Zhao Jan 2013

Independent Component Analysis Enhancements For Source Separation In Immersive Audio Environments, Yue Zhao

Theses and Dissertations--Electrical and Computer Engineering

In immersive audio environments with distributed microphones, Independent Component Analysis (ICA) can be applied to uncover signals from a mixture of other signals and noise, such as in a cocktail party recording. ICA algorithms have been developed for instantaneous source mixtures and convolutional source mixtures. While ICA for instantaneous mixtures works when no delays exist between the signals in each mixture, distributed microphone recordings typically result various delays of the signals over the recorded channels. The convolutive ICA algorithm should account for delays; however, it requires many parameters to be set and often has stability issues. This thesis introduces the …