Biomedical Engineering and Bioengineering Commons^™

Biomechanical Evaluation Of Locked And Non-Locked Constructs Under Axial And Torsion Loading, Vinit A. Patel

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Locking compression plates are proven to be safe for use in open reduction and internal fixation (ORIF). The ORIF is a procedure performed to treat fractures. It has various combination of holes, the system provides more options for clinicians to use either locking screw or non-locking screws. This thesis investigates and determines the best construct with special locking and non-locking screws under both axial and torsion loading. Twenty femur constructs were assembled with 2 cm osteotomy gap between femur shaft and condyle, bridged with 4.5 mm - 10 holes condyle plates. Femurs were divided in to 4 groups according to …

Histogram-Based Template Matching Object Detection In Images With Varying Brightness And Contrast, Christina Da-Wann Schrider

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Our challenge was to develop a semi-automatic target detection algorithm to aid human operators in locating potential targets within images. In contrast to currently available methods, our approach is relatively insensitive to image brightness, image contrast and object orientation. Working on overlapping image blocks, we used a sliding difference method of histogram matching. Incrementally sliding the histograms of the known object template and the image region of interest (ROI) together, the sum of absolute histogram differences was calculated. The minimum of the resultant array was stored in the corresponding spatial position of a response surface matrix. Local minima of the …

Finite Element Optimization Of Hip Implant Geometrical Parameters To Determine Safe Zones And Resist Dislocation, Himanshu K. Bhatt

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A computational study was performed using finite element analysis (FEA) of three dimensional solid hip implant models. Twelve different hip implant models were designed to investigate the performance of geometrical parameters affecting hip stability. The parameters examined were head diameter, neck diameter, head-to-neck ratio, neck angle and acetabular liner thickness. Component orientations included cup anatomical inclination and cup anteversion, which should be accounted for during total hip implant design as well as in the practice of arthroplasties. A static analysis was performed for all 12 hip designs using stainless steel 316L. von Mises stress, contact stress, contact penetration, and sliding …

Motion-Control System Of Bench-Top Ct Scanner, Tarpit Kaushikbhai Patel

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Computed Tomography (CT) imaging has found applications in many areas such as diagnostic visualization, quantitative estimation, and therapeutic verification. In this wide range of applications, a CT scanner that can provide the data collection schemes of both second- and third-generation data-collection geometries will be an asset for laboratory research. In this thesis project, we developed a mechanical design and constructed a dual-generation CT scanner that provides flexibility in accommodating a wide range of object sizes with minimum scan time. Using 3-D graphical design software, models of the current second-generation CT scanner and possible solutions for modification were simulated. Based on …

Performance Analysis Of Quantitative Bone Measurement With Spiral, Multi-Detector Ct Scanners, Shruti Gupta

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The measure of bone strength and fracture risk assessment is based primarily on bone mineral density (BMD). Computed tomography (CT), a frequently used radiographic technique that provides cross-sectional images, can be used for BMD quantification. Called quantitative computed tomography (QCT), it determines true volumetric density and also differentiates between trabecular and cortical bone. As a result, QCT improves the ability to detect early changes in trabecular BMD accurately and precisely.

The introduction of helical CT for quantitative analysis introduces new complexities. Even though using multi-detector helical CT for BMD assessment is being suggested, a detailed analysis of its validity is …

Automated Analysis Of Metacarpal Cortical Thickness In Serial Hand Radiographs, Aarti Raheja

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To understand the roles of various genes that influence skeletal bone accumulation and loss, accurate measurement of bone mineralization is needed. However, it is a challenging task to accurately assess bone growth over a person's lifetime. Traditionally, manual analysis of hand radiographs has been used to quantify bone growth, but these measurements are tedious and may be impractical for a large-scale growth study. The aim of this project was to develop a tool to automate the measurement of metacarpal cortical bone thickness in standard hand-wrist radiographs of humans aged 3 months to 70+ years that would be more accurate, precise …

Novel Redox And Dna-Dependent Conformational Changes In Human Ku, A Dna-Double Strand Break Repair Protein, Jason Alexander Lehman

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Ionizing radiation (IR) and radiomimetic drugs used in cancer chemotherapy cause DNA double-strand breaks which are repaired by the nonhomologous end joining (NHEJ) pathway. Ku is a heterodimeric protein comprised of 70 and 80 kDa subunits and recognizes free DNA ends. Once Ku is bound to DNA, it binds to the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), and forms a heterotrimeric DNA-PK complex for repair and damage signaling.

We have analyzed the Ku protein using multiple biochemical techniques and uncovered a novel reversible redox change (Andrews, Lehman and Turchi, (2006) JBC 281(19):13596-603). From this data, we hypothesized that a redox-dependent …

The Effects Of Chronic Hypoxia And Substance P On The Chemosensitive Response Of Individual Nucleus Tractus Solitarius (Nts) Neurons From Adult Rats, Nicole L. Nichols

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The chemosensitive responses of individual nucleus tractus solitarius (NTS) neurons from neonatal rats have been extensively studied, but few studies have examined the chemosensitive responses of NTS neurons from adult rats. In addition, environmental conditions have been used to mimic respiratory diseases/disorders in rats to study how the cellular responses of individual neurons change to regulate breathing during pathological conditions. Lastly, it has been shown that substance P release increases in response to hypoxia from peripheral afferents that primarily terminate in the caudal NTS. We studied the effect of chronic hypoxia (CHx) and substance P on the response to hypercapnia …