Real-time ultrasonic imaging systems have been available for more than fifty-five years and are becoming an important tool in the practice of modern medicine. During this time much has occurred to the basic architecture and functions of these clinical systems and their beamformers, which are, in many ways, the most important components of these systems. Throughout most of the 30 years of real time imaging, analog beamformers have been the mainstay of all ultrasonic instruments. But at the present time the industry is undergoing a major shift toward digital beamformation with the introduction of several commercial systems. The thesis will look at the evolution of digital ultrasound beamformers, some of the changes that have occurred and will discuss current trends in beamformer design. Typical analog and digital beam formers have been simulated and their performance compared in terms of beam width, side lobe levels and signal-to-noise ratio. Also the effect of apodization on images have been examined. Experimental investigations have been carried out to compare delay-sum-add and synthetic aperture imaging on different phantoms. The technical challenges in digital beamformation win be reviewed, as also the constraints introduced by today's market place. Finally, the future of digital beamformation in the context of advances in computer and microelectronics technologies is discussed.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.21331 |
| Date | January 1998 |
| Creators | Vasudevan, Sunil. |
| Contributors | Watkin, Kenneth L. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Electrical and Computer Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001656721, proquestno: MQ50670, Theses scanned by UMI/ProQuest. |
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