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Full-Text Articles in Medicine and Health Sciences

Motion Artifact Evaluation Of Coronary Ct Angiography Images, Hongfeng Ma Oct 2017

Motion Artifact Evaluation Of Coronary Ct Angiography Images, Hongfeng Ma

Dissertations (1934 -)

The objective of this dissertation was to develop and validate an automated algorithm to quantify motion artifact level on coronary CT angiography (CCTA) images. Unlike existing motion artifact reduction techniques that evaluate the relative level of motion artifacts within one exam, this dissertation aims to quantify the absolute level of motion artifacts across exams from varying patients. The ability to quantify absolute motion artifact level enables several potential applications, for example, assessing and comparing two motion artifact reduction techniques. This dissertation includes three specific aims. Aim 1 investigated the absolute motion artifact quantification effectiveness of six motion artifact metrics using …


Muscle Coordination Contributes To Function After Stroke; Proprioception Contributes To Control Of Posture, Movement, Maria Bengtson Oct 2017

Muscle Coordination Contributes To Function After Stroke; Proprioception Contributes To Control Of Posture, Movement, Maria Bengtson

Dissertations (1934 -)

More than half of stroke survivors experience persistent upper extremity motor impairments that can negatively impact quality of life and independence. Effective use of the upper extremity requires coordination of agonist/antagonist muscle pairs, as well as coordination of multiple control actions for stabilizing and moving the arm. In this dissertation, I present three studies in which I recorded isometric torque production, single joint movement and stabilization, and clinical measures of function and impairments after stroke to evaluate the extent to which changes in coordination of agonist/antagonist muscles and of sequential control actions contribute to deficits after stroke. In Aim 1, …


Effects Of Random Oscillations On Balance Control In Healthy Young Adults, Jacob Van Dehy Oct 2017

Effects Of Random Oscillations On Balance Control In Healthy Young Adults, Jacob Van Dehy

Master's Theses (2009 -)

In human walking, balance control is managed through proactive changes in spatio-temporal parameters of stepping [1]. It has been suggested that continuous disruptions to healthy young adult balance cause greater changes to overall variability of these parameters than a shift in the mean stepping parameters [2]. This suggests that walking may be occurring in a more reactive manner, modulating to maintain balance without increasing the mean significantly. Work using continuous oscillations to treadmill walking suggest there is an interplay between the predictability of a signal used to disrupt subject balance and the degree to which compensation occurs [3]. To determine …


Markerless Kinematics Of Pediatric Manual Wheelchair Mobility, Jacob Robert Rammer Jul 2017

Markerless Kinematics Of Pediatric Manual Wheelchair Mobility, Jacob Robert Rammer

Dissertations (1934 -)

Pediatric manual wheelchair users face substantial risk of orthopaedic injury to the upper extremities, particularly the shoulders, during transition to wheelchair use and during growth and development. Propulsion strategy can influence mobility efficiency, activity participation, and quality of life. The current forefront of wheelchair biomechanics research includes translating findings from adult to pediatric populations, improving the quality and efficiency of care under constrained clinical funding, and understanding injury mechanisms and risk factors. Typically, clinicians evaluate wheelchair mobility using marker-based motion capture and instrumentation systems that are precise and accurate but also time-consuming, inconvenient, and expensive for repeated assessments. There is …


Evaluating Wall Shear Stress Indices To Uncover Stimuli For Restenosis And Malapposition In Stented Coronary Arteries, Ali A. Aleiou Jul 2017

Evaluating Wall Shear Stress Indices To Uncover Stimuli For Restenosis And Malapposition In Stented Coronary Arteries, Ali A. Aleiou

Master's Theses (2009 -)

The cause of coronary artery neointimal thickening leading to restenosis in ~10% of drug-eluting stents is unknown. Although research suggests adverse values of traditional wall shear stress (WSS) indices may contribute, studies to date have not accounted for stent geometry, which dictates local WSS patterns influencing drug concentration. Recently proposed WSS indices such as WSS variability and WSS exposure time (WSSET) may shed further light on restenosis or, the opposite effect, resorption. The objective of this investigation was to locally evaluate traditional and recently proposed post-stenting metrics and their respective impact on restenosis or resorption. This study used de-identified data …