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The ultra-wideband (UWB) radar technique has emerged as an efficient way to detect and image objects non-destructively. Widespread biomedical applications have allowed researchers across the globe to use this technique efficiently. Different tissues of the human body have different electrical properties, and UWB radar microwave systems have the potential to identify the tissue type when there is a considerable permittivity difference between them. Microwave tomography (MWT) has become the preferred imaging technique for biomedical applications to analyze functional and pathological of the tissues. Microwave imaging works best for high dielectric contrast regions such as bones and fatty areas. Recent progress in UWB radar technology and computing hardware has opened up unique opportunities for further research and development of MWT for biomedical and clinical applications. Safety is an essential feature of MWT imaging; this modality uses non-ionizing microwave pulses at average power levels comparable to cell phone radiation. This thesis focuses on analyzing pediatric corpulence (child obesity) and knee osteoarthritis using UWB radar technologies. The first project discusses the UWB radar system and the genetic algorithm to analyze obesity in children by computing both complex permittivity and thickness of adipose tissue. This analysis involves the analytical study of electromagnetic wave interaction with human tissues. The simulation involves the analyses of the proposed technique on human voxel tissue models—including babies, children, and adults—available in CST software. The experimental validation involves the phantom consisting of a pork skin layer followed by pork fat, then ground pork which emulates muscle tissue. When the measured results were compared with the actual permittivity and thickness, the accuracy of measurement data confirmed the suitability of this technique. Based on the electrical properties of adipose tissue, obesity levels were assessed. This technique is a safe, cost-effective, portable, ex vivo, non-contact method to determine the type of fat tissue in the human body and consequently to determine the level of obesity. The second project discusses a non-invasive approach to studying knee osteoarthritis. This technique utilizes a combination of synthetic aperture radar (SAR) focused microwave reflection tomography, and genetic algorithm. This approach estimates osteoarthritis in a patient by analyzing three properties around the knee joint: the complex permittivity, the depth from the skin to the bone, and the gap between the thigh bone and shinbone. The technique is also applied to adult human voxel tissue knees and simplified knee models in the CST software. Simulated validation concludes that the technique is feasible as a safe, cost-effective, and non-contact method for estimating knee osteoarthritis in the human body. |
