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Full-Text Articles in Biomedical Engineering and Bioengineering

Protection Against Cardiac Injury By Small Ca2 +-Sensitive K+ Channels Identified In Guinea Pig Cardiac Inner Mitochondrial Membrane, David F. Stowe, Ashish K. Gadicherla, Yifan Zhou, Mohammed Aldakkak, Qunli Cheng, Wai-Meng Kwok, Ming Tao Jiang, James S. Heisner, Meiying Yang, Amadou K.S. Camara Feb 2013

Protection Against Cardiac Injury By Small Ca2 +-Sensitive K+ Channels Identified In Guinea Pig Cardiac Inner Mitochondrial Membrane, David F. Stowe, Ashish K. Gadicherla, Yifan Zhou, Mohammed Aldakkak, Qunli Cheng, Wai-Meng Kwok, Ming Tao Jiang, James S. Heisner, Meiying Yang, Amadou K.S. Camara

Biomedical Engineering Faculty Research and Publications

We tested if small conductance, Ca2 +‐sensitive K+ channels (SKCa) precondition hearts against ischemia reperfusion (IR) injury by improving mitochondrial (m) bioenergetics, if O2‐derived free radicals are required to initiate protection via SKCa channels, and, importantly, if SKCa channels are present in cardiac cell inner mitochondrial membrane (IMM). NADH and FAD, superoxide (O2), and m[Ca2 +] were measured in guinea pig isolated hearts by fluorescence spectrophotometry. SKCa and IKCa channel opener DCEBIO (DCEB) was given for 10 min and ended 20 min before IR. Either TBAP, a dismutator of O ...


Mechanisms Of Sensorimotor Impairment In Multiple Sclerosis, Matthew Cheeming Chua Jan 2013

Mechanisms Of Sensorimotor Impairment In Multiple Sclerosis, Matthew Cheeming Chua

Dissertations (1934 -)

Sensorimotor impairments in people with multiple sclerosis (MS) might alter coordination and balance strategy during functional movements. People with MS often have symptoms such as weakness and discoordination in the lower limbs, resulting in poor walking and balance function. This decrease in function can result in falls, decreased community activity, unemployment, and reduced quality of life. As MS is a progressive disease resulting in a range of dysfunction, the amount of lower limb impairment can cause changes to walking and balance strategies to maintain functional performance. The overall objective of this dissertation was to quantify the impairment at the hip ...


Reducing Radiation Dose To The Female Breast During Conventional And Dedicated Breast Computed Tomography, Franco Rupcich Jan 2013

Reducing Radiation Dose To The Female Breast During Conventional And Dedicated Breast Computed Tomography, Franco Rupcich

Dissertations (1934 -)

The purpose of this study was to quantify the effectiveness of techniques intended to reduce dose to the breast during CT coronary angiography (CTCA) scans with respect to task-based image quality, and to evaluate the effectiveness of optimal energy weighting in improving contrast-to-noise ratio (CNR), and thus the potential for reducing breast dose, during energy-resolved dedicated breast CT.

A database quantifying organ dose for several radiosensitive organs irradiated during CTCA, including the breast, was generated using Monte Carlo simulations. This database facilitates estimation of organ-specific dose deposited during CTCA protocols using arbitrary x-ray spectra or tube-current modulation schemes without the ...


Vascular Changes In Type 2 Diabetes Mellitus: Application To Restenosis After Stenting, Hongfeng Wang Jan 2013

Vascular Changes In Type 2 Diabetes Mellitus: Application To Restenosis After Stenting, Hongfeng Wang

Dissertations (1934 -)

Stents used to decrease cardiovascular risk in patients with type 2 diabetes mellitus (T2DM) are prone to increased rates of restenosis. The mechanisms are incompletely elucidated, but low wall shear stress (WSS) and altered intracellular signaling likely contribute. We tested the hypothesis that neointimal hyperplasia (NH) after bare-metal stenting is due to vascular remodeling (enhanced formation of advanced glycation end-products (AGEs), increased downstream vascular resistance (DVR), and decreased WSS), and that decreasing AGEs with ALT-711 (Alagebrium) mitigates this response.

Stents were implanted into the abdominal aorta of Zucker lean (ZL), obese (ZO), and diabetic (ZD) rats. After 21 days, the ...


Diffusion Tensor Imaging Of The Central Nervous System Following An Injury To The Spinal Cord And Cell Transplant, Michael Jirjis Jan 2013

Diffusion Tensor Imaging Of The Central Nervous System Following An Injury To The Spinal Cord And Cell Transplant, Michael Jirjis

Dissertations (1934 -)

The purpose of this dissertation research was to characterize the use of magnetic resonance diffusion tensor imaging (DTI) as a diagnostic and prognostic tool in understanding the changes that occur throughout the spinal cord and brain following a spinal cord injury (SCI) and following stem cell transplant. The diffusion of water inside the nervous system is dramatically altered around the lesion site following a traumatic SCI. However, following damage to the spinal cord, little is known about the diffusion characteristics away from an injury and even less is understood about DTI's sensitivity to structural changes that occur following regenerative ...


Visuomotor Learning Enhanced By Augmenting Instantaneous Trajectory Error Feedback During Reaching, James L. Patton, John Wei Yejun, Preeti Bajaj, Robert A. Scheidt Jan 2013

Visuomotor Learning Enhanced By Augmenting Instantaneous Trajectory Error Feedback During Reaching, James L. Patton, John Wei Yejun, Preeti Bajaj, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

We studied reach adaptation to a 30u visuomotor rotation to determine whether augmented error feedback can promote faster and more complete motor learning. Four groups of healthy adults reached with their unseen arm to visual targets surrounding a central starting point. A manipulandum tracked hand motion and projected a cursor onto a display immediately above the horizontal plane of movement. For one group, deviations from the ideal movement were amplified with a gain of 2 whereas another group experienced a gain of 3.1. The third group experienced an offset equal to the average error seen in the initial perturbations ...


Comparison Of Randomized Multifocal Mapping And Temporal Phase Mapping Of Visual Cortex For Clinical Use, Yan Ma, B. Douglas Ward, Kristina M. Ropella, Edgar A. Deyoe Jan 2013

Comparison Of Randomized Multifocal Mapping And Temporal Phase Mapping Of Visual Cortex For Clinical Use, Yan Ma, B. Douglas Ward, Kristina M. Ropella, Edgar A. Deyoe

Biomedical Engineering Faculty Research and Publications

fMRI is becoming an important clinical tool for planning and guidance of surgery to treat brain tumors, arteriovenous malformations, and epileptic foci. For visual cortex mapping, the most popular paradigm by far is temporal phase mapping, although random multifocal stimulation paradigms have drawn increased attention due to their ability to identify complex response fields and their random properties. In this study we directly compared temporal phase and multifocal vision mapping paradigms with respect to clinically relevant factors including: time efficiency, mapping completeness, and the effects of noise. Randomized, multifocal mapping accurately decomposed the response of single voxels to multiple stimulus ...


A Hands-On, Active Learning Approach To Increasing Manufacturing Knowledge In Engineering Students, Jay R. Goldberg, David B. Rank Jan 2013

A Hands-On, Active Learning Approach To Increasing Manufacturing Knowledge In Engineering Students, Jay R. Goldberg, David B. Rank

Biomedical Engineering Faculty Research and Publications

This paper describes a new learning module implemented as part of the senior capstone design course at Marquette University to teach engineering students about basic manufacturing processes, lean manufacturing principles, and design for manufacturability. The module includes several examples of active and student centered learning as part of an in-class assembly line simulation exercise. Students reflected on this experience, and suggested process improvements to save time, reduce cost and waste, and improve the assembly line process. They learned of the importance of manufacturing documentation, process design, and design for assembly. At the end of the module, students understood the importance ...


Biplane Fluoroscopic Analysis Of The Hindfoot Using Model-Based Tracking Techniques: A Static Phantom Study, Janelle A. Cross, Ben Mchenry, Gerald F. Harris, Taly Gilat Schmidt Jan 2013

Biplane Fluoroscopic Analysis Of The Hindfoot Using Model-Based Tracking Techniques: A Static Phantom Study, Janelle A. Cross, Ben Mchenry, Gerald F. Harris, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

No abstract provided.


White Matter Structural Connectivity Is Associated With Sensorimotor Function In Stroke Survivors, Benjamin Kalinosky, Sheila M. Schindler-Ivens, Brian D. Schmit Jan 2013

White Matter Structural Connectivity Is Associated With Sensorimotor Function In Stroke Survivors, Benjamin Kalinosky, Sheila M. Schindler-Ivens, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Purpose

Diffusion tensor imaging (DTI) provides functionally relevant information about white matter structure. Local anatomical connectivity information combined with fractional anisotropy (FA) and mean diffusivity (MD) may predict functional outcomes in stroke survivors. Imaging methods for predicting functional outcomes in stroke survivors are not well established. This work uses DTI to objectively assess the effects of a stroke lesion on white matter structure and sensorimotor function.

Methods

A voxel-based approach is introduced to assess a stroke lesion's global impact on motor function. Anatomical T1-weighted and diffusion tensor images of the brain were acquired for nineteen subjects (10 post-stroke and ...


In Vivo Dark-Field Imaging Of The Retinal Pigment Epithelium Cell Mosaic, Drew Scoles, Yusufu N. Sulai, Alfredo Dubra Jan 2013

In Vivo Dark-Field Imaging Of The Retinal Pigment Epithelium Cell Mosaic, Drew Scoles, Yusufu N. Sulai, Alfredo Dubra

Biomedical Engineering Faculty Research and Publications

Non-invasive reflectance imaging of the human RPE cell mosaic is demonstrated using a modified confocal adaptive optics scanning light ophthalmoscope (AOSLO). The confocal circular aperture in front of the imaging detector was replaced with a combination of a circular aperture 4 to 16 Airy disks in diameter and an opaque filament, 1 or 3 Airy disks thick. This arrangement reveals the RPE cell mosaic by dramatically attenuating the light backscattered by the photoreceptors. The RPE cell mosaic was visualized in all 7 recruited subjects at multiple retinal locations with varying degrees of contrast and cross-talk from the photoreceptors. Various experimental ...


Safety And Efficacy Of Ranolazine For The Treatment Of Chronic Angina Pectoris, Mohammed Aldakkak, David F. Stowe, Amadou K.S. Camara Jan 2013

Safety And Efficacy Of Ranolazine For The Treatment Of Chronic Angina Pectoris, Mohammed Aldakkak, David F. Stowe, Amadou K.S. Camara

Biomedical Engineering Faculty Research and Publications

Coronary heart disease is a global malady and it is the leading cause of death in the United States. Chronic stable angina is the most common manifestation of coronary heart disease and it results from the imbalance between myocardial oxygen supply and demand due to reduction in coronary blood flow. Therefore, in addition to lifestyle changes, commonly used pharmaceutical treatments for angina (nitrates, ß-blockers, Ca2+ channel blockers) are aimed at increasing blood flow or decreasing O2 demand. However, patients may continue to experience symptoms of angina. Ranolazine is a relatively new drug with anti-anginal and anti-arrhythmic effects. Its anti-anginal mechanism ...


Brittle Bone Fracture Risk With Transverse Isotropy, Jessica M. Fritz, Nicole M. Grosland, Peter A. Smith, Gerald F. Harris Jan 2013

Brittle Bone Fracture Risk With Transverse Isotropy, Jessica M. Fritz, Nicole M. Grosland, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.


Biomechanical Modeling Of Pediatric Clubfoot, Gerald F. Harris Jan 2013

Biomechanical Modeling Of Pediatric Clubfoot, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.


Markerless Analysis Of Upper Extremity Kinematics During Standardized Pediatric Functional Assessment With A Low-Cost Motion Analysis System, Gerald F. Harris, Susan A. Riedel Jan 2013

Markerless Analysis Of Upper Extremity Kinematics During Standardized Pediatric Functional Assessment With A Low-Cost Motion Analysis System, Gerald F. Harris, Susan A. Riedel

Biomedical Engineering Faculty Research and Publications

No abstract provided.


Improving Brain–Machine Interface Performance By Decoding Intended Future Movements, Francis R. Willett, Aaron J. Suminski, Andrew H. Fagg, Nicholas G. Hatsopoulos Jan 2013

Improving Brain–Machine Interface Performance By Decoding Intended Future Movements, Francis R. Willett, Aaron J. Suminski, Andrew H. Fagg, Nicholas G. Hatsopoulos

Biomedical Engineering Faculty Research and Publications

Objective. A brain–machine interface (BMI) records neural signals in real time from a subject's brain, interprets them as motor commands, and reroutes them to a device such as a robotic arm, so as to restore lost motor function. Our objective here is to improve BMI performance by minimizing the deleterious effects of delay in the BMI control loop. We mitigate the effects of delay by decoding the subject's intended movements a short time lead in the future. Approach. We use the decoded, intended future movements of the subject as the control signal that drives the movement of ...


3d Visualization Of Reference-Point Indentation In Human And Murine Bone, John Jameson, Alex Proctor, Carolyne Albert, Gerald F. Harris Jan 2013

3d Visualization Of Reference-Point Indentation In Human And Murine Bone, John Jameson, Alex Proctor, Carolyne Albert, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.


3d Micron-Scale Imaging Of The Cortical Bone Canal Network In Human Osteogenesis Imperfecta (Oi), John R. Jameson, Carolyne Albert, Bjoern Busse, Peter A. Smith, Gerald F. Harris Jan 2013

3d Micron-Scale Imaging Of The Cortical Bone Canal Network In Human Osteogenesis Imperfecta (Oi), John R. Jameson, Carolyne Albert, Bjoern Busse, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Osteogenesis imperfecta (OI) is a genetic disorder leading to increased bone fragility. Recent work has shown that the hierarchical structure of bone plays an important role in determining its mechanical properties and resistance to fracture. The current study represents one of the first attempts to characterize the 3D structure and composition of cortical bone in OI at the micron-scale. A total of 26 pediatric bone fragments from 18 individuals were collected during autopsy (Nc=5) or routing orthopaedic procedures (NOI=13) and imaged by microtomography with a synchrotron light source (SRµCT) for several microstructural parameters including cortical porosity ...


Experimental Study Of Optimal Energy Weighting In Energy-Resolved Ct Using A Czt Detector, Franco Rupcich, Taly Gilat-Schmidt Jan 2013

Experimental Study Of Optimal Energy Weighting In Energy-Resolved Ct Using A Czt Detector, Franco Rupcich, Taly Gilat-Schmidt

Biomedical Engineering Faculty Research and Publications

Recent advances in energy-resolved CT can potentially improve contrast-to-noise ratio (CNR), which could subsequently reduce dose in conventional and dedicated breast CT. Two methods have been proposed for optimal energy weighting: weighting the energy-bin data prior to log normalization (projection-based weighting) and weighting the energy-bin data after log normalization (image-based weighting). Previous studies suggested that optimal projection-based and image-based energy weighting provide similar CNR improvements for energy-resolved CT compared to photon-counting or conventional energy-integrating CT. This study experimentally investigated the improvement in CNR of projection-based and image-based weighted images relative to photon-counting for six different energy-bin combinations using a bench ...


Foot And Ankle Motion Analysis Using Dynamic Radiographic Imaging, Benjamin Donald Mchenry Jan 2013

Foot And Ankle Motion Analysis Using Dynamic Radiographic Imaging, Benjamin Donald Mchenry

Dissertations (1934 -)

Lower extremity motion analysis has become a powerful tool used to assess the dynamics of both normal and pathologic gait in a variety of clinical and research settings. Early rigid representations of the foot have recently been replaced with multi-segmental models capable of estimating intra-foot motion. Current models using externally placed markers on the surface of the skin are easily implemented, but suffer from errors associated with soft tissue artifact, marker placement repeatability, and rigid segment assumptions. Models using intra-cortical bone pins circumvent these errors, but their invasive nature has limited their application to research only. Radiographic models reporting gait ...