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Biomedical Engineering and Bioengineering

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Articles 8911 - 8940 of 11461

Full-Text Articles in Engineering

The Effect Of Cox-2 Specific Inhibition On Direct Fracture Healing In The Rabbit Tibia, David J. Hak, Kurt S. Schulz, Behrang Khoie, Scott J. Hazelwood Jan 2011

The Effect Of Cox-2 Specific Inhibition On Direct Fracture Healing In The Rabbit Tibia, David J. Hak, Kurt S. Schulz, Behrang Khoie, Scott J. Hazelwood

Biomedical Engineering

Objective: The purpose of this study was to evaluate the effect of Cox-2 administration on direct (primary) fracture healing.

Methods: A transverse tibial osteotomy was created in adult male rabbits and rigidly fixed in compression using a 2.7-mm dynamic compression plate. Animals were randomized to receive either rofecoxib (12.5 mg orally per day) or placebo. Animals were killed at 4 weeks and fracture healing assessed by mechanical testing.

Results: There were no significant differences between the control and Cox-2 treated animals in terms of mechanical strength at 4 weeks. There was a high complication rate of peri-implant fractures …


An Evolved Adeno-Associated Viral Variant Enhances Gene Delivery And Gene Targeting In Neural Stem Cells, Jae-Hyung Jang, James Koerber, Jung-Suk Kim, Prashanth Asuri, Tandis Vazin, Melissa Bartel, Albert Keung, Inchan Kwan, David Schaffer Jan 2011

An Evolved Adeno-Associated Viral Variant Enhances Gene Delivery And Gene Targeting In Neural Stem Cells, Jae-Hyung Jang, James Koerber, Jung-Suk Kim, Prashanth Asuri, Tandis Vazin, Melissa Bartel, Albert Keung, Inchan Kwan, David Schaffer

Bioengineering

Gene delivery to, and gene targeting in, stem cells would be a highly enabling technology for basic science and biomedical application. Adeno-associated viral (AAV) vectors have demonstrated the capacity for efficient delivery to numerous cells, but their application to stem cells has been limited by low transduction efficiency. Due to their considerable advantages, however, engineering AAV delivery systems to enhance gene delivery to stem cells may have an impact in stem cell biology and therapy. Therefore, using several diverse AAV capsid libraries—including randomly mutagenized, DNA shuffled, and random peptide insertion variants—we applied directed evolution to create a “designer” AAV vector …


Augmented Control Of A Hands-Free Electrolarynx, Brian Madden, James Condron, Eugene Coyle Jan 2011

Augmented Control Of A Hands-Free Electrolarynx, Brian Madden, James Condron, Eugene Coyle

Conference Papers

During voiced speech, the larynx acts as the sound source, providing a quasi-periodic excitation of the vocal tract. Following a total laryngectomy, some people speak using an electrolarynx which employs an electromechanical actuator to perform the excitatory function of the absent larynx. Drawbacks of conventional electrolarynx designs include the monotonic sound emitted, the need for a free-hand to operate the device, and the difficulty experienced by many laryngectomees in adapting to its use. One improvement to the electrolarynx, which clinicians and users frequently suggest, is the provision of a convenient hands-free control facility. This would allow more natural use of …


High Power, Low Frequency Ultrasound: Meniscal Tissue Interaction And Ablation Characteristics, Brendan O'Daly, Edmund Morris, Graham Gavin, Conor Keane, John O Byrne, Garrett Mcguinness Jan 2011

High Power, Low Frequency Ultrasound: Meniscal Tissue Interaction And Ablation Characteristics, Brendan O'Daly, Edmund Morris, Graham Gavin, Conor Keane, John O Byrne, Garrett Mcguinness

Articles

Abstract—This study evaluates high power low frequency ultrasound transmitted via a flat vibrating probe tip as an alternative technology for meniscal debridement in the bovine knee. An experimental force controlled testing rig was constructed using a 20 kHz ultrasonic probe suspended vertically from a load cell. Effect of variation in amplitude of distal tip displacement (242–494 mm peak-peak) settings and force (2.5–4.5 N) on tissue removal rate (TRR) and penetration rate (PR) for 52 bovine meniscus samples was analyzed. Temperature elevation in residual meniscus was measured by embedded thermocouples and histologic analysis. As amplitude or force increases, there is a …


A Full-Depth Amalgamated Parallel 3d Geometric Multigrid Solver For Gpu Clusters, Dana A. Jacobsen, Inanc Senocak Jan 2011

A Full-Depth Amalgamated Parallel 3d Geometric Multigrid Solver For Gpu Clusters, Dana A. Jacobsen, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Numerical computations of incompressible flow equations with pressure-based algorithms necessitate the solution of an elliptic Poisson equation, for which multigrid methods are known to be very efficient. In our previous work we presented a dual-level (MPI-CUDA) parallel implementation of the Navier-Stokes equations to simulate buoyancy-driven incompressible fluid flows on GPU clusters with simple iterative methods while focusing on the scalability of the overall solver. In the present study we describe the implementation and performance of a multigrid method to solve the pressure Poisson equation within our MPI-CUDA parallel incompressible flow solver. Various design decisions and algorithmic choices for multigrid methods …


Scalability Of Incompressible Flow Computations On Multi-Gpu Clusters Using Dual-Level And Tri-Level Parallelism, Dana A. Jacobsen, Inanc Senocak Jan 2011

Scalability Of Incompressible Flow Computations On Multi-Gpu Clusters Using Dual-Level And Tri-Level Parallelism, Dana A. Jacobsen, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

High performance computing using graphics processing units (GPUs) is gaining popularity in the scientific computing field, with many large compute clusters being augmented with multiple GPUs in each node. We investigate hybrid tri-level (MPI-OpenMP-CUDA) parallel implementations to explore the efficiency and scalability of incompressible flow computations on GPU clusters up to 128 GPUS. This work details some of the unique issues faced when merging fine-grain parallelism on the GPU using CUDA with coarse-grain parallelism using OpenMP for intra-node and MPI for inter-node communication. Comparisons between the tri-level MPI-OpenMP-CUDA and dual-level MPI-CUDA implementations are shown using computationally large computational fluid dynamics …


The Hemocompatibility Of A Nitric Oxide Generating Polymer That Catalyzes S-Nitrosothiol Decomposition In An Extracorporeal Circulation Model, Terry C. Major, David O. Brant, Charles P. Burney, Kagya Amoako, Gail M. Annich, Mark E. Meyerhoff, Hitesh Handa, Robert E. Bartlett Jan 2011

The Hemocompatibility Of A Nitric Oxide Generating Polymer That Catalyzes S-Nitrosothiol Decomposition In An Extracorporeal Circulation Model, Terry C. Major, David O. Brant, Charles P. Burney, Kagya Amoako, Gail M. Annich, Mark E. Meyerhoff, Hitesh Handa, Robert E. Bartlett

Mechanical and Industrial Engineering Faculty Publications

Nitric oxide (NO) generating (NOGen) materials have been shown previously to create localized increases in NO concentration by the catalytic decomposition of blood S-nitrosothiols (RSNO) via copper (Cu)-containing polymer coatings and may improve extracorporeal circulation (ECC) hemocompatibility. In this work, a NOGen polymeric coating composed of a Cuo-nanoparticle (80 nm)-containing hydrophilic polyurethane (SP-60D-60) combined with the intravenous infusion of an RSNO, S- nitroso-N-acetylpenicillamine (SNAP), is evaluated in a 4 h rabbit thrombogenicity model and the anti-thrombotic mechanism is investigated. Polymer films containing 10 wt.% Cuo-nanoparticles coated on the inner walls of ECC circuits are employed concomitantly with systemic SNAP administration …


Blood Vessel Diameter Estimation System Using Active Contours, Jane Courtney, Ana Tizon Jan 2011

Blood Vessel Diameter Estimation System Using Active Contours, Jane Courtney, Ana Tizon

Conference Papers

The study and analysis of blood vessel geometry has become the basis of medical applications related to early diagnosis and effective monitoring of therapies in vascular diseases. This paper presents a new method to trace the outline of blood vessels from imperfect images and extract useful information about their dimensions in an automated manner. The system consists of a segmentation procedure that uses two Active Contours to detect blood vessel boundaries and a novel approach to measure blood vessel diameters directly as the distance between two points. We have succeeded in designing and implementing an automated, robust, measurement method that …


Characterising 3d Soft Tissue Features On Joint Surfaces, Colm O'Kane Jan 2011

Characterising 3d Soft Tissue Features On Joint Surfaces, Colm O'Kane

Other resources

A crucial aspect of orthopaedic implant design is the prediction of surgical outcomes when the shape of a bone is necessarily altered by the addition of the implant. Matching native kinematics as closely as possible is generally considered a core aim of joint replacement surgery. The overall hypothesis behind this research is that soft tissue geometry, including cartilage thickness distribution and ligament attachment sites, influences kinematics in the knee joint. In order to enable investigation of possible links between geometry and kinematics, the ability to characterise the shape variation of the soft tissue relative to the underlying bony geometry must …


High-Frequency Ultrasound For Intraoperative Margin Assessments In Breast Conservation Surgery: A Feasibility Study, Timothy E. Doyle, Rachel E. Factor, Christina L. Ellefson, Kristina M. Sorensen, Brady J. Ambrose, Jeffrey B. Goodrich, Vern P. Hart, Scott C. Jensen, Hemang Patel, Leigh A. Neumayer Jan 2011

High-Frequency Ultrasound For Intraoperative Margin Assessments In Breast Conservation Surgery: A Feasibility Study, Timothy E. Doyle, Rachel E. Factor, Christina L. Ellefson, Kristina M. Sorensen, Brady J. Ambrose, Jeffrey B. Goodrich, Vern P. Hart, Scott C. Jensen, Hemang Patel, Leigh A. Neumayer

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

In addition to breast imaging, ultrasound offers the potential for characterizing and distinguishing between benign and malignant breast tissues due to their different microstructures and material properties. The aim of this study was to determine if high-frequency ultrasound (20-80 MHz) can provide pathology sensitive measurements for the ex vivo detection of cancer in margins during breast conservation surgery.

Methods

Ultrasonic tests were performed on resected margins and other tissues obtained from 17 patients, resulting in 34 specimens that were classified into 15 pathology categories. Pulse-echo and through-transmission measurements were acquired from a total of 57 sites on the …


3d Imaging For Planning Of Minimally Invasive Surgical Procedures, Uma Numburi Jan 2011

3d Imaging For Planning Of Minimally Invasive Surgical Procedures, Uma Numburi

ETD Archive

Novel minimally invasive surgeries are used for treating cardiovascular diseases and are performed under 2D fluoroscopic guidance with a C-arm system. 3D multidetector row computed tomography (MDCT) images are routinely used for preprocedural planning and postprocedural follow-up. For preprocedural planning, the ability to integrate the MDCT with fluoroscopic images for intraprocedural guidance is of clinical interest. Registration may be facilitated by rotating the C-arm to acquire 3D C-arm CT images. This dissertation describes the development of optimal scan and contrast parameters for C-arm CT in 6 swine. A 5-s ungated C-arm CT acquisition during rapid ventricular pacing with aortic root …


One-Dimensional Radial Diffusion Of Small Molecules (376 Da) In Bone Tissue, Kurt W. Farrell Jan 2011

One-Dimensional Radial Diffusion Of Small Molecules (376 Da) In Bone Tissue, Kurt W. Farrell

ETD Archive

The flow of nutrients through any biological tissue is important to maintain homeostasis. If the transport process is understood, medical research teams can better design medications, prosthetic implants, and tissue scaffolds. Additionally, transport rates help physicians to better understand disease states and wound healing, including minor injuries such as breaks and sprains, which will aid in better diagnoses. We developed a novel method that measures the rate of diffusion in vitro, of fluorescein sodium salt. Samples were incubated at 37°C in a 5 CO2 atmosphere for various periods of time. Samples were sliced and analyzed using Image-Pro Plus and MATLAB …


Modification, Expression, And Purification Of Hyperactive Antifreeze Proteins From Insect Tenebrio Molitor, Sen Bu Jan 2011

Modification, Expression, And Purification Of Hyperactive Antifreeze Proteins From Insect Tenebrio Molitor, Sen Bu

ETD Archive

Antifreeze proteins (AFPs), also known as thermal hysteresis proteins, can protect organisms from damage caused by freezing by lowering the freezing point of fluids. AFPs can bind to small ice crystals, inhibit ice growth, and change the morphology of ice crystals. The difference between the freezing temperature and the melting temperature is termed thermal hysteresis (TH). There are different types of AFPs, such as fish AFPs (type I, II, III, and IV) and insect AFPs. These AFPs can also be classified by their thermal hysteresis activity: moderately active AFPs and hyperactive AFPs. Previous research groups successfully constructed AFP (type I, …


Characterization Of Elastin-Like Polypeptides Using Viscometry, Hamdan Noman Alanazi Jan 2011

Characterization Of Elastin-Like Polypeptides Using Viscometry, Hamdan Noman Alanazi

ETD Archive

Elastin-like polypeptides (ELPs) are a class of polypeptide polymers that are gaining interest in various potential applications. These polymers are responsive to the changes in their environment by exhibiting conformational changes and aggregation. Monodisperse elastin-like polypeptides, (GVGVP)40, (GVGVP)40-foldon, and (GVGVP)60-foldon are made in bacterial expression system. An Ubbelohde capillary viscometer was set up to characterize the structural changes of these ELPs in phosphate buffered saline (PBS) solution. For the ELP-foldon, the relative viscosity measurements were utilized to calculate the intrinsic viscosities using Kraemer and Huggins equations. The known molecular weights of the ELPs and the experimentally determined intrinsic viscosities facilitated …


Electrochemical Investigation Of Chromium Nanocarbide Coated Ti-6al-4v And Co-Cr-Mo Alloy Substrates, Viswanathan Swaminathan, Haitong Zeng, Daniel Lawrynowicz, Zongtao Zhang, Jeremy L. Gilbert Jan 2011

Electrochemical Investigation Of Chromium Nanocarbide Coated Ti-6al-4v And Co-Cr-Mo Alloy Substrates, Viswanathan Swaminathan, Haitong Zeng, Daniel Lawrynowicz, Zongtao Zhang, Jeremy L. Gilbert

Biomedical and Chemical Engineering - All Scholarship

This study investigated the electrochemical behavior of chromium nano-carbide cermet coating applied on Ti–6Al–4V and Co–Cr–Mo alloys for potential application as wear and corrosion resistant bearing surfaces. The cermet coating consisted of a highly heterogeneous combination of carbides embedded in a metal matrix. The main factors studied were the effect of substrate (Ti–6Al–4V vs. Co–Cr–Mo), solution conditions (physiological vs. 1 M H2O2 of pH 2), time of immersion (1 vs. 24 h) and post coating treatments (passivation and gamma sterilization). The coatings were produced with high velocity oxygen fuel (HVOF) thermal spray technique at atmospheric conditions to …


The Influence Of Interleukin-4 On Ligament Healing, Connie S. Chamberlain, Ellen M. Leiferman, Kayt E. Frisch, Sijian Wang, Xipei Yang, Stacey L. Brickson, Ray Vanderby Jan 2011

The Influence Of Interleukin-4 On Ligament Healing, Connie S. Chamberlain, Ellen M. Leiferman, Kayt E. Frisch, Sijian Wang, Xipei Yang, Stacey L. Brickson, Ray Vanderby

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Despite a complex cascade of cellular events to reconstruct the damaged extracellular matrix, ligament healing results in a mechanically inferior scarred ligament. During normal healing, granulation tissue expands into any residual normal ligamentous tissue (creeping substitution), resulting in a larger region of healing, greater mechanical compromise and an inefficient repair process. To control creeping substitution and possibly enhance the repair process, the antiinflammatory cytokine, interleukin-4 (IL-4), was administered to rats before and after rupture of their medial collateral ligaments. In vitro experiments showed a time-dependent effect on fibroblast proliferation after IL-4 treatment. In vivo treatments with IL-4 (100 ng/mL IV) …


Ultrasound Echo Is Related To Stress And Strain In Tendon, Sarah Duenwald, Hirohito Kobayashi, Kayt E. Frisch, Roderic Lakes, Ray Vanderby Jr. Jan 2011

Ultrasound Echo Is Related To Stress And Strain In Tendon, Sarah Duenwald, Hirohito Kobayashi, Kayt E. Frisch, Roderic Lakes, Ray Vanderby Jr.

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

The mechanical behavior of tendons has been well studied in vitro. A noninvasive method to acquire mechanical data would be highly beneficial. Elastography has been a promising method of gathering in vivo tissue mechanical behavior, but it has inherent limitations. This study presents acoustoelasticity as an alternative ultrasound-based method of measuring tendon stress and strain by reporting a relationship between ultrasonic echo intensity (B-mode ultrasound image brightness) and mechanical behavior of tendon in vitro. Porcine digital flexor tendons were cyclically loaded in a mechanical testing system while an ultrasonic echo response was recorded. We report that echo intensity …


The Influence Of Macrophage Depletion On Ligament Healing, Connie S. Chamberlain, Ellen M. Leiferman, Kayt E. Frisch, Sijian Wang, Xipei Yang, Nico Van Rooijen, Geoff S. Baer, Stacey L. Brickson, Ray Vanderby Jan 2011

The Influence Of Macrophage Depletion On Ligament Healing, Connie S. Chamberlain, Ellen M. Leiferman, Kayt E. Frisch, Sijian Wang, Xipei Yang, Nico Van Rooijen, Geoff S. Baer, Stacey L. Brickson, Ray Vanderby

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Despite a complex cascade of cellular events to reconstruct damaged extracellular matrix (ECM), ligament healing results in a mechanically inferior, scar-like tissue. During normal healing, the number of macrophages significantly increases within the wound site. Then, granulation tissue expands into any residual, normal ligamentous tissue (creeping substitution), resulting in a larger region of healing, greater mechanical compromise, and an inefficient repair process. To study the effects of macrophages on the repair process, bilateral, surgical rupture of their medial collateral ligaments (MCLs) was done on rats. Treatment animals received liposome-encapsulated clodronate, 2 days before rupture to ablate phagocytosing macrophages. Ligaments were …


Custom-Molded Foot-Orthosis Intervention And Multisegment Medial Foot Kinematics During Walking, Mark Geil Jan 2011

Custom-Molded Foot-Orthosis Intervention And Multisegment Medial Foot Kinematics During Walking, Mark Geil

Faculty Articles

No abstract provided.


Nitric Oxide-Generating Silicone As A Blood-Contacting Biomaterial, Kagya Amoako Jan 2011

Nitric Oxide-Generating Silicone As A Blood-Contacting Biomaterial, Kagya Amoako

Mechanical and Industrial Engineering Faculty Publications

Coagulation upon blood-contacting biomaterials remains a problem for short and long-term clinical applications. This study examined the ability of copper(II)-doped silicone surfaces to generate nitric oxide (NO) and locally inhibit coagulation. Silicone was doped with 3-micron copper (Cu(0)) particles yielding 3 to 10 weight percent (wt%) Cu in 70-μm thick Cu/Silicone polymeric matrix composites (Cu/Si PMCs). At 3, 5, 8 and 10 wt% Cu doping, the surface expression of Cu was 12.1 ± 2.8%, 19.7 ± 5.4%, 29.0 ± 3.8%, and 33.8 ± 6.5% respectively. After oxidizing Cu(0) to Cu(II) by spontaneous corrosion, NO flux, JNO (mol*cm−2*min−1), as measured by …


Fusion And Visualization Of Intraoperative Cortical Images With Preoperative Models For Epilepsy Surgical Planning And Guidance., A Wang, S M Mirsattari, A G Parrent, T M Peters Jan 2011

Fusion And Visualization Of Intraoperative Cortical Images With Preoperative Models For Epilepsy Surgical Planning And Guidance., A Wang, S M Mirsattari, A G Parrent, T M Peters

Robarts Imaging Publications

OBJECTIVE: During epilepsy surgery it is important for the surgeon to correlate the preoperative cortical morphology (from preoperative images) with the intraoperative environment. Augmented Reality (AR) provides a solution for combining the real environment with virtual models. However, AR usually requires the use of specialized displays, and its effectiveness in the surgery still needs to be evaluated. The objective of this research was to develop an alternative approach to provide enhanced visualization by fusing a direct (photographic) view of the surgical field with the 3D patient model during image guided epilepsy surgery.

MATERIALS AND METHODS: We correlated the preoperative plan …


Design Of An Implant For First Metatarsophalangeal Joint Hemiarthroplasty, Atul Kumar Jan 2011

Design Of An Implant For First Metatarsophalangeal Joint Hemiarthroplasty, Atul Kumar

ETD Archive

Osteoarthritis (OA) is the most common form of arthritis and it affects 27 million US adults. OA disease involves all of the tissues of the diarthrodial joint and ultimately, may lead to softening, ulceration, loss of articular cartilage, sclerosis and polished appearance of the subchondral bone, osteophytes, and subchondral cysts. The first metatarsophalangeal joint (MTPJ1) is affected in up to 42 cases of OA. Besides osteoarthritis, other conditions such as rheumatoid arthritis and gout also affect the MTPJ1. Involvement of MTPJ1 with these conditions invariably leads to deformed toe such as hallux valgus and hallux rigidus. Over 150 surgical techniques …


Development Of A Muscle Force Optimization Algorithm To Improve Center Of Pressure During Simulated Walking, Lawrence Dean Noble Jan 2011

Development Of A Muscle Force Optimization Algorithm To Improve Center Of Pressure During Simulated Walking, Lawrence Dean Noble

ETD Archive

The Universal Musculoskeletal Simulator (UMS) was developed at the Cleveland Clinic to facilitate general purpose orthopaedic research that allows investigators to study the in vitro forces applied to bones, tendons and ligaments during simulated exercise of cadaver joint systems. In its original state, the UMS hardware consisted of a rotopod (a specialized hexapod robot), a single rotary tendon actuator and custom LabVIEW software for coordinated control and operation of the system. The focus of this work was to 1) enhance the UMS with a multi-tendon actuator system, 2) develop a muscle force optimization algorithm and evaluate it with a static …


Quantification Of Scenedesmus Dimorphus Growth And Substrate Kinetics For Continuous Photobioreactor Design, Daniela Ribita Jan 2011

Quantification Of Scenedesmus Dimorphus Growth And Substrate Kinetics For Continuous Photobioreactor Design, Daniela Ribita

ETD Archive

Increasing gas prices, limited fossil fuel resources and U.S. dependence on foreign oil make research in alternative fuels a priority. The feasibility of producing fuels from microalgae is economically dependent on improvements in lipid productivity by the algae. The research presented here focuses on the development of a mathematical model to describe the biomass and lipid productivity in a continuously-operated photobioreactor (PBR) system. Five different cell lysing methods were evaluated for the purpose of improving the methods of analysis of lipid synthesis. The two most promising methods were found to be mortar and pestle and organic solvent cell fractionation methods. …


Algea Suspension Dewatering With An Inclined Gravity Settler, Jing Hou Jan 2011

Algea Suspension Dewatering With An Inclined Gravity Settler, Jing Hou

ETD Archive

Biofuel has been studied for several decades as a feasible substitute for petroleum, which may solve the energy crisis. Having a high oil content and growth rate, algae biofuels have received lots of attention recently, and have been considered as one of the most promising technologies to reduce the dependence of fossil fuels. In the process of producing algae biofuel, the dewatering process constitutes a significant part of the cost of the algae biofuel, impeding progress towards large-scale commercial use. An inclined settler utilizes gravity to separate algae cells from the fluid, with little energy consumption. The separation ability of …


Investigations Of Anatomical Connectivity In The Internal Capsule Of Macaques With Diffusion Magnetic Resonance Imaging, Kyle Andrew Ignatius Taljan Jan 2011

Investigations Of Anatomical Connectivity In The Internal Capsule Of Macaques With Diffusion Magnetic Resonance Imaging, Kyle Andrew Ignatius Taljan

ETD Archive

Understanding anatomical connectivity is crucial for improving outcomes of deep brain stimulation surgery. Tractography is a promising method for noninvasively investigating anatomical connectivity, but connections between subcortical regions have not been closely examined by this method. As many connections to subcortical regions converge at the internal capsule (IC), we investigate the connectivity through the IC to three subcortical nuclei (caudate, lentiform nucleus, and thalamus) in 6 macaques. We show that a statistical correction for a known distance-related artifact in tractography results in large changes in connectivity patterns. Our results suggest that care should be taken in using tractography to assess …


A Left Ventricular Motion Phantom For Cardiac Magnetic Resonance Imaging, Mehmet Ersoy Jan 2011

A Left Ventricular Motion Phantom For Cardiac Magnetic Resonance Imaging, Mehmet Ersoy

ETD Archive

The mammalian left ventricle (LV) has two distinct motion patterns: wall thickening and rotation. The purpose of this study was to design and build a low-cost, non-ferromagnetic LV motion phantom, for use with cardiac magnetic resonance imaging (MRI), that is able to produce physiologically realistic LV wall thickening and rotation. Cardiac MRI is continuously expanding its range of techniques with new pulse sequences, including new tissue tagging techniques which allow intra-myocardial deformation to be visualized. An essential step in the development of new cardiac MRI techniques is validating their performance in the presence of motion. MRI-compatible dynamic motion phantoms are …


Assessment Of Circumferential Myocardial Function Using Radial Tagged Mri, Yujaung Kim Jan 2011

Assessment Of Circumferential Myocardial Function Using Radial Tagged Mri, Yujaung Kim

ETD Archive

The extent of myocardial abnormalities is related to cardiac disease. The assessment of myocardial function of the left ventricular (LV) described by the LV myocardial deformation plays an important role to understand the effects of cardiovascular disease and therapeutic interventions on LV motion. Cardiac magnetic resonance imaging (CMR) is widely agreed as the most accurate noninvasive imaging modality for the assessment of left ventricular (LV) function. In addition, myocardial-tagging technique can track the myocardial deformation by labeling specific regions. Although the grid tagging is popular in cardiac research use, it has not been adopted into routine clinical examination with unreliable …


A Concept For Direct Control Of Rotary Blood Pump Speed By Inlet Pressure, Ibrahim Seven Jan 2011

A Concept For Direct Control Of Rotary Blood Pump Speed By Inlet Pressure, Ibrahim Seven

ETD Archive

Heart failure remains a major health problem for the world. Heart transplantation is the most effective treatment for end stage heart failure. A major problem with heart transplantation is finding adequate numbers of appropriate donors. The lack of donor numbers in the world creates a significant clinical need for blood pumping devices. The ability of ventricular assist devices to relieve the consequences of less than terminal heart failure further creates a need for assist therapy. Current new ventricular assist devices are built around continuous flow technology. These nonpulsatile assist devices have had major clinical success in relieving symptoms and increasing …


Effect Of Step Change In Growth Speed During Directional Solidification On Array Morphology Of Al-7 Wt Si Alloy, Swapna Pakiru Jan 2011

Effect Of Step Change In Growth Speed During Directional Solidification On Array Morphology Of Al-7 Wt Si Alloy, Swapna Pakiru

ETD Archive

No abstract provided.