Amplifier for optimal reflection Coefficient of ultrasound transducer: A study of op amp based circuits for ultrasound transducers, targeted for low reflection Coefficient, high gain, and low noise
Master thesis
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http://hdl.handle.net/11250/2370499Utgivelsesdato
2012Metadata
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Sammendrag
Reverberation is defined as equally-spaced, bright linear echoes resulting from reflection from specular-type interfaces. They are provoked by the acoustic Impedance change between the tissue and transducer front surface. B. Angelsen developed a mathematical approach to correct this ultrasound artifact by coupling the ultrasound transducer with an ideal electrical load in order to obtain zero reflection coefficients on the transducer from face [1]. However, when analyzing Impedance spectroscopy this approach cannot be achieved by using passive electronics in most simulated cases. Active impedance may be seen as a trend to improve image quality. This research therefore implements and simulates methods for active impedance synthesis [5] and applies Particle Swarm Optimization to the proposed electronics. Finally, the simulations are compared through a LAB experiment.