Biomedical Engineering and Bioengineering Commons^™

Integration Of Microfluidics With Surface Plasmon Resonance, Scott B. Fratzke

Master's Theses

This thesis successfully integrates laminate microfluidic devices with an analytic Surface Plasmon Resonance (SPR) instrument. Integration was accomplished at low-cost using materials such as polydimethylsiloxane (PDMS), Poly(methyl methacrylate) (PMMA), Tygon tubing, and a 3-way stopcock. The main components of this thesis are the design and fabrication of the low-cost, in-house fluidics that can integrate with upstream microfluidics and the validation of the in-house fluidics using the Biosensing Instruments BI-2000 SPR instrument. The low-cost fluidics was designed and fabricated “in-house” using a novel investment casting technique that required the use of laser cutting technology to make a master cast, and candle …

Pre-Swing Deficits In Forward Propulsion, Swing Initiation And Power Generation By Individual Muscles In Hemiparetic Walking, Carrie L. Peterson, Allison Kinney, Steven A. Kautz, Richard R. Neptune

Mechanical and Aerospace Engineering Faculty Publications

Clinical studies of hemiparetic walking have shown pre-swing abnormalities in the paretic leg suggesting that paretic muscle contributions to important biomechanical walking subtasks are different than those of non-disabled individuals. Three-dimensional forward dynamics simulations of two representative hemiparetic subjects with different levels of walking function classified by self-selected walking speed (i.e., limited community=0.4–0.8 m/s and community walkers=>0.8 m/s) and a speed-matched control were generated to quantify individual muscle contributions to forward propulsion, swing initiation and power generation during the pre-swing phase (i.e., double support phase proceeding toe-off). Simulation analyses identified decreased paretic soleus and gastrocnemius contributions to forward propulsion …

Relationships Between Muscle Contributions To Walking Subtasks And Functional Walking Status In Persons With Post-Stroke Hemiparesis, Allison Kinney, Carrie L. Peterson, Steven A. Kautz, Richard R. Neptune

Mechanical and Aerospace Engineering Faculty Publications

Walking speed is commonly used to predict stroke severity and assess functional walking status (i.e., household, limited community and community walking status) post-stroke. The underlying mechanisms that limit walking speed (and functional walking status by extension) need to be understood to improve post-stroke rehabilitation. Previous experimental studies have shown correlations between paretic plantarflexor output during the pre-swing phase and walking speed and suggest that the paretic hip flexors can compensate in some hemiparetic subjects. Modeling and simulation studies of healthy walking have shown that the ankle plantarflexors, soleus (SOL) and gastrocnemius (GAS), and uniarticular hip flexors (IL) are essential contributors …

Evaluation Of Ethanol And Water Introduction Via Fumigation On Efficiency And Emissions Of A Compression Ignition Engine Using An Atomization Technique, Grant S. Janousek

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Performance of a diesel engine, equipped for ethanol and water fumigation, was studied. The method implemented allowed for non-destructive introduction of liquids in advance of the turbocharger. Engine torque, speed, emission components, diesel and ethanol fuel rates were recorded and analyzed for each mixture of inputs. Based on the results of the study, thermal efficiency was not significantly different from the baseline diesel performance when using several ethanol and water mixtures. On the other hand, ethanol fumigation caused a significant reduction in NOx emissions and an increase in HC and CO emissions. No significant changes in CO2 or O2 occurred.

Design And Validation Of An Mr Conditional Upper Extremity Evaluation System To Study Brain Activation Patterns After Stroke, Rubing Xu

Master's Theses (2009 -)

Stroke is the third leading cause of death and second most frequent cause of disability in the United States. Stroke rehabilitation methods have been developed to induce the cortical reorganization and motor-relearning that leads to stroke recovery. In this thesis, we designed and developed an MR conditional upper extremity reach and grasp movement evaluation system for the stroke survivors to study their kinematic performances in reach and grasp movement and the relationship between kinematic metrics and the recovery level measured by clinical assessment methods. We also applied the system into the functional MRI experiments to identify the ability to study …

Quantification Of 99mTc-Duramycin Uptake Kinetics In The Area-At-Risk After Myocardial Ischemia And Reperfusion, Joseph Capacete

Master's Theses (2009 -)

Myocardial infarction (MI) is a condition in which blood supply to the heart is insufficient. MI is associated with two forms of cell death: apoptosis and necrosis. ^99mTc-duramycin (^99mTc-D) is a novel radiopharmaceutical that detects cell death by recognizing externalized phosphatidylethanolamine. The objective of this study was to develop a compartmental model for ^99mTc-D uptake kinetics in normal and infarct myocardium, and utilize this model to compare the uptake kinetics of ^99mTc-D in MI with that of another radiopharmaceutical, ^99mTc-C2A-GST.

MI was induced in rats which were then injected (i.v.) with ^99mTc-D. Rats …

Enhanced Anthocyanin Extraction From Red Cabbage Using Pulsed Electric Field Processing, Tanya K. Gachovska, David A. Cassada, Jeyamkondan Subbiah, Milford Hanna, Harshavardhan Thippareddi, Daniel D. Snow

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study was conducted to evaluate the effect of pulsed electric field (PEF) treatment on anthocyanin extraction from red cabbage using water as a solvent. Mashed cabbage was placed in a batch treatment chamber and subjected to PEF (2.5 kV/cm electric field strength; 15 μs pulse width and 50 pulses, specific energy 15.63 J/g). Extracted anthocyanin concentrations (16 to 889 μg/mL) were determined using HPLC. Heat and light stabilities of the control and PEF-treated samples, having approximately the same initial concentrations, were studied. PEF treatments enhanced total anthocyanin extraction in water from red cabbage by 2.15 times with a higher …

Application Of Signal Advance Technology To Electrophysiology, Chris M. Hymel

Dissertations and Theses (Open Access)

Medical instrumentation used in diagnosis and treatment relies on the accurate detection and processing of various physiological events and signals. While signal detection technology has improved greatly in recent years, there remain inherent delays in signal detection/ processing. These delays may have significant negative clinical consequences during various pathophysiological events. Reducing or eliminating such delays would increase the ability to provide successful early intervention in certain disorders thereby increasing the efficacy of treatment.

In recent years, a physical phenomenon referred to as Negative Group Delay (NGD), demonstrated in simple electronic circuits, has been shown to temporally advance the detection of …

Hemocompatibility And Endothelialization Of Elastin And Collagen Scaffolds: The Role Of Plasma Proteins, Shear Stress And Integrins, Nithya Swaminathan

All Theses

Cardiovascular diseases are the leading cause of death worldwide as reported by the World Health Organization. Biomaterials have been extensively used in blood-contacting applications as heart valves, stents, grafts and catheters. However failure due to thrombosis hinders the long term patency and potential of these devices. Purified elastin scaffolds derived from porcine arteries as potential vascular graft materials are being investigated in our laboratory. In this study, we investigated the influence of factors such as shear stress and the presence of plasma proteins on the platelet response, and endothelial cell retention on purified elastin scaffolds to evaluate their hemocompatibility.

Elastin …

In Vitro Analysis Of Auto-Loom Woven Test Patches For Hernia Repair, Bryant Mersereau

All Theses

Hernias are defects in the layers of the abdominal wall that can cause discomfort or pain and lead to serious health problems if left untreated. A significant portion of the world's population is afflicted by hernia formation, and the cost of treating those affected is in the billions of dollars in the US alone. The current best practices for repairing hernias involve the surgical implantation of polymeric meshes over and around the defect site. The mesh, acting as a synthetic replacement for the damaged abdominal wall layers, provides a barrier to further visceral protrusions through the defect, a support framework …

Probing The Mechanisms Of Platelet Adhesion To Adsorbed Plasma Proteins, Balakrishnan Sivaraman

All Dissertations

Despite over three decades of research in blood-material interactions, the biomaterials field has been unsuccessful in developing a truly non-thrombogenic biomaterial. This is due to an incomplete understanding of the factors underlying biomaterial-associated thrombosis, especially the mechanisms mediating the interactions of platelets with the adsorbed plasma protein layer(s) on the implant surface. The work presented here is motivated by the primary goal of delineating these mechanisms, and understanding the platelet receptors involved, as well as the domains/amino acid sequences they bind to in the protein molecules.
It is critical to differentiate between the amount and the conformation of the adsorbed …

Immunohistochemical Mapping Of Hypoxia In Ischemic Mouse Hindlimb Skeletal Muscle, Emily Deckert

Biomedical Engineering

The study of blood vessel growth and remodeling is a complex endeavor. Hypoxia, the lack of oxygen in a tissue, is known to stimulate angiogenesis (the growth of new blood vessels), and have little effect on arteriogenesis (the enlargement of existing blood vessels). However, the role of hypoxia in vessel function is unknown, but may be determined using the results and methods developed in this experiment.

Supplied by the bloodstream, oxygen is required by all cells and tissues to remain healthy. If the bloodstream supplying a certain tissue with blood is disrupted, the tissue becomes ischemic, often leading to hypoxia. …

Fracture Of Bone Using Microindentation, Séverine Vennin

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Osteoporosis is a current disease which is especially of concern to post-menopausal women. It is characterized by a decrease of bone density and an increase in the risk of fracture. Interest in the fracture mechanisms with respect to the underlying biological structure of the bone is of great interest to researchers in this field. In this thesis, a new method based on microindentation on rat femurs was developed to determine the relation between the viscoelastic and the fracture properties of bone. The main goal is to measure the viscoelastic properties by using a dynamic mechanical analysis indentation method and then …

St. Jude Medical: An Object-Oriented Software Architecture For Embedded And Real-Time Medical Devices, Atila Amiri

Master's Theses

Medical devices used for surgical or therapeutic purposes require a high degree of safety and effectiveness. Software is critical component of many such medical devices. The software architecture of a system defines organizational structure and the runtime characteristic of the application used to control the operation of the system and provides a set of frameworks that are used to develop that. As such, the design of software architecture is a critical element in achieving the intended functionality, performance, and safety requirements of a medical device. This architecture uses object-oriented design techniques, which model the underlying system as a set of …

St. Jude Medical: Enhanced Mics (Emics), Devanshi Shah

Master's Theses

Heart disease is one of the most prevalent diseases in the world. The survival chances for patients with ventricular fibrillation/ventricular tachycardia reduces significantly as time passes without treatment and even after getting timely treatment recurring episode are common. These patients can benefit from an Implantable Cardioverter Defibrillator (ICD) which can monitor heart rhythm and provide immediate treatment. Due to the ever changing physical conditions and disease progression, the ICD needs to collect diagnostic data as well as support programming by the physician. The ICD uses inductive telemetry and radio-frequency telemetry for the communication with the external devices such as a …

Mitochondrial Free [Ca2+] Increases During Atp/Adp Antiport And Adp Phosphorylation: Exploration Of Mechanisms, Johan Haumann, Ranjan K. Dash, David F. Stowe, Age D. Boelens, Daniel A. Beard, Amadou K.S. Camara

Biomedical Engineering Faculty Research and Publications

ADP influx and ADP phosphorylation may alter mitochondrial free [Ca²⁺] ([Ca²⁺]_m) and consequently mitochondrial bioenergetics by several postulated mechanisms. We tested how [Ca²⁺]_m is affected by H₂PO₄⁻ (P_i), Mg²⁺, calcium uniporter activity, matrix volume changes, and the bioenergetic state. We measured [Ca²⁺]_m, membrane potential, redox state, matrix volume, pH_m, and O₂ consumption in guinea pig heart mitochondria with or without ruthenium red, carboxyatractyloside, or oligomycin, and at several levels of Mg²⁺ and P_i. …

Local Hemodynamic Changes Caused By Main Branch Stent Implantation And Subsequent Side Branch Balloon Angioplasty In A Representative Coronary Bifurcation, Andrew R. Williams, Bon-Kwon Koo, Timothy J. Gundert, Peter J. Fitzgerald, John F. Ladisa Jr.

Biomedical Engineering Faculty Research and Publications

Abnormal blood flow patterns promoting inflammation, cellular proliferation, and thrombosis may be established by local changes in vessel geometry after stent implantation in bifurcation lesions. Our objective was to quantify altered hemodynamics due to main vessel (MV) stenting and subsequent virtual side branch (SB) angioplasty in a coronary bifurcation by using computational fluid dynamics (CFD) analysis. CFD models were generated from representative vascular dimensions and intravascular ultrasound images. Time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and fractional flow reserve (FFR) were quantified. None of the luminal surface was exposed to low TAWSS (/cm2) in the nondiseased bifurcation model. …

Eye Movements In Elite Athletes - An Index For Performance., Harshad Hegde

Theses and Dissertations

Introduction: In gymnastics, athletes perform twisting and flipping skills at high angular velocities. These athletes rely heavily on sensory information from the visual, proprioceptive, and vestibular systems. The vestibulo-ocular reflex (VOR) is responsible for stabilizing the visual field on the retina during head movement. To accomplish this, the eyes are reflexively moved in a direction opposite the head. In a twisting gymnast, this actually reduces the ability of gymnasts to see the landing during airborne skills. Hence it becomes necessary for the gymnasts to cancel or suppress their VOR in order to view the landing. Objective: The purpose of this …

Effect Of Mechanical Stimulation On Mesenchymal Stem Cell Seeded Cartilage Constructs, Karin Wartella

Theses and Dissertations

Cartilage tissue engineered constructs using mesenchymal stem cells were stimulated with 3 different stimulation algorithms to achieve characteristics mimicking the superficial tangential zone of articular cartilage. The stimulation algorithm of both compression and tension without an offset had the best properties out of all the evaluated groups.

Synthesis And Characterization Of A Novel Amphiphilic Core-Corona Hyperbranched Polymer, Composed Of Ehmo And Ehmopeg, For Drug Delivery., Khushboo Sharma

Theses and Dissertations

A novel amphiphilic core-corona hyperbranched polymer, composed of 3-ethyl-3-(hydroxylmethyl) oxetane (EHMO) and PEGylated EHMO (EHMOPEG), was synthesized through cationic ring opening polymerization. Nuclear Magnetic Resonance spectroscopy (NMR), Dynamic Light Scattering (DLS), and Fourier Transform Infrared spectroscopy (FTIR) were used to characterize the polymer structure and degree of branching. It was found that the degree of branching (DOB) of the polymer was affected by the weight % ratios of EHMO/EHMOPEG used in polymerization. As the weight % ratio of EHMO/ EHMOPEG decreased, the DOB was observed to increase. Polymeric particles based on the synthesized polymer were prepared using the O/W (Oil …