Near field imaging using microwaves in medical applications is of great current
interest for its capability and accuracy in identifying features of interest, in
comparison with other known screening tools. Many imaging methods have been
developed over the past two decades showing the potential of microwave imaging
in medical applications such as early breast cancer detection, analysis of cardiac
tissues, soft tissues and bones. Microwave imaging uses non-ionizing ultra wideband (UWB) electromagnetic signals and utilises tissue-dependent dielectric
contrast to reconstruct signals and images using radar-based or tomographic
imaging techniques. Microwave imaging offers low health risk, low operational
cost, ease of use and user-friendliness.
This study documents microwave imaging experiments for early breast cancer
detection and bone fracture detection using radar approach. An actively tuned
UWB patch antenna and a UWB Vivaldi antenna are designed and utilised as
sensing elements in the aforementioned applications. Both UWB antennas were
developed over a range of frequency spectrum, and then characteristics were
tested against their ability for microwave imaging applications by reconstructing
the 3D Inversion Algorithm.
An experiment was conducted using patch antenna to test the detection of
variable sizes of cancer tissues based on a simple phantom consisting of a plastic
container with a low dielectric material emulating fatty tissue and high dielectric
constant object emulating a tumour, is scanned between 4 to 8 GHz with the patch antenna. A 2-D image of the tumour is constructed using the reflected
signal response to visualize the location and size of the tumour.
A Vivaldi antenna is designed covering 3.1 to 10.6 GHz. The antenna is tested
via simulation for detecting bone fractures of various sizes and 2-D images are
generated using reflected pulses to show the size of fracture. The Vivaldi antenna
is optimised for early breast cancer detection and detailed simulated study is
carried out using different breast phantoms and tumour sizes. Simulations are
backed with the experimental investigation with the test setup used for patch
antenna. Generated images for simulations and experimental investigation show
good agreement, and show the presence of tumour with good location accuracy.
Measurements indicate that both prototype microwave sensors are good
candidates for tested imaging applications.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/18784 |
| Date | January 2019 |
| Creators | Mirza, Ahmed F. |
| Contributors | Abd-Alhameed, Raed, Noras, James M. |
| Publisher | University of Bradford, Faculty of Engineering and Informatics |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Thesis, doctoral, PhD |
| Rights | <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. |
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