Experimental Analysis on Effectiveness of Confocal Algorithm for Radar Based Breast Cancer Detection

Breast cancer is one of the most commonly diagnosed cancers in females in UK [1]. Early breast cancer detection which has recently been gaining a lot of consideration within the research community and the most important for a quick and effective treatment of the cancer is early detection. UWB radar based microwave imaging for early breast cancer detection is one of the most promising and attractive screening techniques currently under research. This technique offers several advantages such as low cost, better patient comfort, non-ionising and non-invasive radiation compared to X-Ray mammography. In this technique the breast is illuminated from various points with short UWB microwave pulse(s) and the collected backscattered energy is then processed to identify the presence and location of the tumour. In this thesis experimental measurement of the reflection coefficient in complex frequency domain is obtained from Vector Network Analyzer (VNA E5071) when the antenna is exposed to the environment and when the antenna is exposed to breast phantom. The tumor is simulated with different materials to investigate the effectiveness of the Confocal Microwave Imaging Algorithm for breast cancer detection. In addition, we used the materials at different depths to determine the effect of antenna distance to that of the tumor response. The Confocal Microwave Imaging (CMI) Algorithm for breast cancer detection is an easy and robust technique for tumor detection, which is used to approximate the precise location of the tumor. CMI is based on illuminating the breast with the UWB pulse from different antenna locations. The relative arrival times & amplitudes of the backscatter signals is used to estimate the location of the tumor. We applied the Confocal Algorithm in this study to the numerical data generated with the VNA and analyzed the results with different material(s) as tumor at different depth to verify its ability to estimate a tumor response

A comparison of Male and Female Medical Student's Motivation towards Career Choice

Objective: To compare motivation to become a doctor in both genders Study Design: Observational cross-sectional study Place and Duration of Study:  Rawalpindi Medical University in March 2019. Materials and Methods: First and second-year M.B.B.S students were included in the study. Age, year of study, and gender were recorded.  The questionnaire included 18 questions assessing six motivational dimensions: status and security; nature of the occupation; career opportunities; patient care and working with people; use of personal skills; and interest in science. Responses were recorded as ‘agree’ or ‘disagree’ for each question and results were analyzed using SPSS v19. Results: Out of 350 medical students, 247 (70.6%) were female and 103 (29.4%) were male. Most frequent motivational factors for females were “Opportunity to care for/ help people” (n=240; 97.1%) followed by “responsible job” (n=220; 89%) and “use of mental skills” (n=217; 87.8%). Male students were motivated mostly by “use of mental skills” (n=90; 87.3%) followed by “provides secure career” (n=87; 84.4%) and “challenging field” (n=83; 80.5%). In our study, (n=61; 25%) of females responded in agreement that boosts in marriage perspective was an underlying motivational factor for their choice of studying medicine while (n=41; 40%) males agreed to it. There was a significant difference between both genders with a p-value of 0.005.  Conclusions: We infer that female medical students have more humanitarian grounds for choosing the medical profession and are more motivated than their male counterparts

Analysis of cylindrical semiconductor metal-clad nano-lasers

The thesis discusses research on analysis of cylindrical metal clad nano-lasers. Numerical modelling of cylindrical semiconductor nano-lasers has been undertaken accommodating local gain variations in the active region of the device. Analysis is performed using the cylindrical transfer matrix method (cTMM) and the Finite Element Method (FEM). Calculations have thereby been performed of the modal gain and the lasing condition for the device supporting TE guided mode and TM Surface Plasmon Polariton (SPP) modes. For representative structures it is shown that TE and TM mode lasing can be supported in devices having cavity lengths on the order of 1μm and 60μm respectively. The methodology adopted offers means to analyse candidate semiconductor lasers. Attention is also given on structures having GaN as the material platform and utilising silver for the metal cladding. The lasing characteristics of such structures are explored for wide range of operating wavelengths and metal – cladding thicknesses. It is found that for lower order TE and TM mode lasing can be supported in devices having cavity lengths of the order of 2μm and 18μm respectively. The response of metal clad nano-lasers to direct current modulation has also been analysed in both the small signal and large signal regimes. Calculations have been performed using rate equations which include the Purcell cavity enhanced spontaneous emission factor, F, and the spontaneous emission coupling factor β. It is observed that in general increased F and β reduce the 3dB direct current modulation bandwidth. Conditions are identified where the peak modulation response occurs at frequencies 40GHz and 30 GHz can be achieved. For both small and large signal regimes modulation bandwidth of approximately 60GHz can be achieved

Analysis of cylindrical semiconductor metal-clad nano-lasers

The thesis discusses research on analysis of cylindrical metal clad nano-lasers. Numerical modelling of cylindrical semiconductor nano-lasers has been undertaken accommodating local gain variations in the active region of the device. Analysis is performed using the cylindrical transfer matrix method (cTMM) and the Finite Element Method (FEM). Calculations have thereby been performed of the modal gain and the lasing condition for the device supporting TE guided mode and TM Surface Plasmon Polariton (SPP) modes. For representative structures it is shown that TE and TM mode lasing can be supported in devices having cavity lengths on the order of 1μm and 60μm respectively. The methodology adopted offers means to analyse candidate semiconductor lasers. Attention is also given on structures having GaN as the material platform and utilising silver for the metal cladding. The lasing characteristics of such structures are explored for wide range of operating wavelengths and metal – cladding thicknesses. It is found that for lower order TE and TM mode lasing can be supported in devices having cavity lengths of the order of 2μm and 18μm respectively. The response of metal clad nano-lasers to direct current modulation has also been analysed in both the small signal and large signal regimes. Calculations have been performed using rate equations which include the Purcell cavity enhanced spontaneous emission factor, F, and the spontaneous emission coupling factor β. It is observed that in general increased F and β reduce the 3dB direct current modulation bandwidth. Conditions are identified where the peak modulation response occurs at frequencies 40GHz and 30 GHz can be achieved. For both small and large signal regimes modulation bandwidth of approximately 60GHz can be achieved