Description
A Master of Science thesis in Biomedical Engineering by Mohanad Ahmed Alkhodari entitled, “The Use of Microwave Tomography in Bone Healing Monitoring”, submitted in April 2019. Thesis advisors are Dr. Amer Zakaria and Dr. Nasser Qaddoumi. Soft and hard copy available.
Abstract
In this thesis, a numerical study is conducted to investigate the use of microwave tomography in monitoring bone health in human lower limbs. By monitoring bone volume fraction (BVF) and bone density, the effectiveness of Vitamin D treatment can be evaluated for osteoporosis patients. In microwave tomography, the leg is radiated with non-ionizing low-power electromagnetic signals with scattered electric fields measured at several locations surrounding the leg. Within the framework of inverse scattering problems, the measured fields are used as inputs for an optimization algorithm to estimate the location and electrical properties inside the human leg. In this work, three two-dimensional cross-sectional models of human leg at different fat thicknesses are created and simulated using a finite-element method, where the transverse magnetic approximation is applied. The synthetic results are then inverted using a finite-element contrast source inversion method. Furthermore, an enhancement procedure is followed to investigate the effect of incorporating prior information about the object-of-interest (OI), changing the boundaries of the imaging domain, relocating antennas, and using ultrasound gel as a matching medium. In addition, an image processing approach is provided to build estimated models to be used in the enhancement procedure. The final results show that variations in BVF affect the results of the inversion algorithm. The real part relative permittivity line plots showed a downward trend as the BVF increases, which can be related to an increase in the bone density. The outcomes of this thesis support the hypothesis that a MWT wearable system is useful for bone density monitoring application, and more specifically for Vitamin D treatment evaluation.