Engineering Commons^™

Fabrication And Mechanical Characterization Of A Two-Ply Cross Fiber Stent And Fibers Comprising Blends Of Poly(L-Lactic Acid), Sushma Gampa

Bioengineering Theses - Archive

Recent studies indicate that stabilization of vulnerable atherosclerotic plaques is critical for minimizing acute coronary syndromes. In this regard a new biodegradable stent design, the Two-ply cross fiber stent, has been developed to reduce stent-imposed stresses on such plaque and to provide increased drug reservoir capability. A comparative study of the mechanical properties of Two-ply and Single-ply stent designs was performed. Fibers comprising PLLA blends were developed and their thermal and mechanical properties were determined. Lateral spreading of helical fibers upon deployment of the Two ply design was observed that, in theory, may reduce stresses on the plaque surface. The …

Parametric And Non-Parametric Analysis Of Carotid Sinus Baroreflex System Using Electrically Induced Muscle Contraction, Sheetal D. Deshmukh

Bioengineering Theses - Archive

The arterial pressure is an important physiological parameter which if not maintained at desired level may lead to fatal disorders or in worst situations even death. The physiological feedback control mechanism in order to regulate the arterial pressure is performed by the baroreceptors. In this study the dynamic characteristics of carotid sinus baroreceptor are identified to obtain the open-loop characteristics of the carotid sinus pressure (CSP, mmHg) to the renal sympathetic nerve activity (RSNA, Arbitrary unit), RSNA to systemic arterial pressure (SAP, mmHg), CSP to SAP and CSP to heart rate (HR, bpm).The purpose of this study was to know …

Dynamic Determinants Of Incisal Display, Shawn Paul Pesh

Loma Linda University Electronic Theses, Dissertations & Projects

The principal objective of this study was to use computer aided design (CAD) to better illustrate and quantify the relationship of mandibular arch depth, mandibular arch width, overbite, and overjet in the presence of mandibular dental crowding. To date, there has been no research examining how changes in the mandibular arch limit the orthodontist's ability to control overbite and overjet. Understanding how to effectively manage overbite and overjet are crucial to the clinician's ability to manipulate incisal display. Polyvinyl siloxane impressions of both maxillary and mandibular arches of a Caucasian patient were taken and used to pour dental stone models. …

Ricketts And Steiner Analysis Using Newtom 3g™ Scout Images, James I. Gibson Iii

Loma Linda University Electronic Theses, Dissertations & Projects

NewTom 3G™ scout images have the general appearance of traditional lateral cephalometric radiographs. The purpose of this research was to determine if Ricketts and Steiner analyses could be accomplished on NewTom 3G™ scout images.

This was a retrospective study comparing the use of NewTom 3G™ scans in DICOM (Digital Imaging and Communications in Medicine) format to scout images from 25 consecutive patients of the Loma Linda University School of Dentistry Department of Orthodontics, three of these patients did not meet the inclusion criteria. The DICOM images were used to create controls. The controls and scout images were digitized using QuickCeph™. …

Remapping Hand Movements In A Novel Geometrical Environment, Kristine M. Mosier, Robert A. Scheidt, Santiago Acosta, Ferdinando A. Mussa-Ivaldi

Biomedical Engineering Faculty Research and Publications

The issue of how the Euclidean properties of space are represented in the nervous system is a main focus in the study of visual perception, but is equally relevant to motor learning. The goal of our experiments was to investigate how the properties of space guide the remapping of motor coordination. Subjects wore an instrumented data glove that recorded the finger motions. Signals generated by the glove operated a remotely controlled endpoint: a cursor on a computer monitor. The subjects were instructed to execute movements of this endpoint with controlled motions of the fingers. This required inverting a highly redundant …

Genetic Engineering Of Plants Through Manipulation Of Lignin Biosynthesis, Vincent Lee C. Chiang, Chung-Jui Tsai, Wen-Jing Hu

Michigan Tech Patents

The invention pertains to the genetically down regulating a lignin pathway p-coumarate Co-enzyme A ligase (CCL) in trees.

Investigation Of The Electro-Mechanical Properties Of A Carbon Fiber-Sodium Composite Material For The Purpose Of Structural Health Monitoring, Sharon Austin

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Industrial Technology by Sharon Austin on November 15, 2005.

Manure Use Planning Tools For Nebraska, Charles S. Wortmann, Charles A. Shapiro, Richard K. Koelsch, Richard Deloughery

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Three computer programs have been developed to facilitate manure use planning. The Nebraska Manure Value Calculator was developed in Excel to ease the calculation of manure value (www.cnmp.unl.edu) for a specific field giving value to needed nutrients and other expected benefits, and with the option of giving value to manure nutrients used in the more distant future. Nebraska MMPAMUP and MMP-CNMP Document Generators are planning tools for animal feeding operations that work with the Purdue University Manure Management Planner (MMP). Microsoft Word documents are generated which contain some boilerplate text that can be edited, popup lists in Word AutoText to …

Are We Addressing The Cause Of Nutrient Problems?, Richard K. Koelsch

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Content:

Manure P vs. Crop Land P Use

One-Way Flow of Nutrients Is Underlying Cause

Future NMP Checklist?

Should an NMP Measure Environmental Performance?

Whole Farm Nutrient Balance

Whole Farm N Balance

Phosphorus Inputs to Livestock Systems

Should An NMP Estimate Ammonia Emissions?

Daily Ammonia Emissions from Livestock (36 km grid)

Ammonia Emissions Regulatory Thresholds

Ammonia Emissions – Swine Finishing Operations

In Vitro And In Vivo Two-Photon Luminescence Imaging Of Single Gold Nanorods, Haifeng Weng, Terry B. Huff, Daniel A. Zweifel, Wei He, Philip S. Low, Alexander Wei, Ji-Xin Cheng

Other Nanotechnology Publications

Gold nanorods excited at 830 nm on a far-field laser-scanning microscope produced strong two-photon luminescence (TPL) intensities, with a cos(4) dependence on the incident polarization. The TPL excitation spectrum can be superimposed onto the longitudinal plasmon band, indicating a plasmon-enhanced two-photon absorption cross section. The TPL signal from a single nanorod is 58 times that of the two-photon fluorescence signal from a single rhodamine molecule. The application of gold nanorods as TPL imaging agents is demonstrated by in vivo imaging of single nanorods flowing in mouse ear blood vessels.

Effect Of Chronic Hyperoxic Exposure On Duroquinone Reduction In Adult Rat Lungs, Said H. Audi, Robert D. Bongard, Gary S. Krenz, David A. Rickaby, Steven Thomas Haworth, Jessica Eisenhauer, David L. Roerig, Marilyn P. Merker

Biomedical Engineering Faculty Research and Publications

NAD(P)H:quinone oxidoreductase 1 (NQO1) plays a dominant role in the reduction of the quinone compound 2,3,5,6-tetramethyl-1,4-benzoquinone (duroquinone, DQ) to durohydroquinone (DQH₂) on passage through the rat lung. Exposure of adult rats to 85% O₂ for ≥7 days stimulates adaptation to the otherwise lethal effects of >95% O₂. The objective of this study was to examine whether exposure of adult rats to hyperoxia affected lung NQO1 activity as measured by the rate of DQ reduction on passage through the lung. We measured DQH₂ appearance in the venous effluent during DQ infusion at different concentrations into …

Engineering Substrate-Mediated Gene Delivery With Self-Assembled Monolayers, Angela K. Pannier, Lonnie D Shea

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Gene transfer has many potential applications in basic and applied sciences, including functional genomics, gene therapy, and tissue engineering. Substrate- mediated delivery, also termed solid phase delivery, describes the immobilization of DNA, complexed with nonviral vectors, to a biomaterial or substrate that supports cell adhesion. A critical component to this process is designing the appropriate interactions between the DNA complexes and substrate. The objective of this study was to investigate gene transfer as a function of i) complex formation and deposition conditions and ii) non-specific and specific binding interactions between the complexes and substrate. The volume and time of complex …

A Three-Dimensional Reconstruction Algorithm For An Inverse-Geometry Volumetric Ct System, Taly Gilat Schmidt, Rebecca Fahrig, Norbert J. Pelc

Biomedical Engineering Faculty Research and Publications

An inverse-geometry volumetric computed tomography (IGCT) system has been proposed capable of rapidly acquiring sufficient data to reconstruct a thick volume in one circular scan. The system uses a large-area scanned source opposite a smaller detector. The source and detector have the same extent in the axial, or slice, direction, thus providing sufficient volumetric sampling and avoiding cone-beam artifacts. This paper describes a reconstruction algorithm for the IGCT system. The algorithm first rebins the acquired data into two-dimensional (2D) parallel-ray projections at multiple tilt and azimuthal angles, followed by a 3D filtered backprojection. The rebinning step is performed by gridding …

Where’S The Poop? Environmental Challenges For Large And Small Animal Feeding Operations, Richard K. Koelsch, John Lawrence

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Content:

Where’s the Poop?

Status and Trends in Small and Mid-Sized Animal Operations in the U.S.

Numbers of farms, animals, & nutrients

Non-confined animals: Farms and AU

Confined animals: Farms and AU

Confined animals: Manure nutrients

Confined animals: Farms with excess manure

AFO Challenges

Bang-for-the-Buck Programming

Wavelet Based Feature Extraction And Dimension Reduction For The Classification Of Human Cardiac Electrogram Depolarization Waveforms, Christopher S. De Voir

Dissertations and Theses

An essential task for a pacemaker or implantable defibrillator is the accurate identification of rhythm categories so that the correct electrotherapy can be administered. Because some rhythms cause a rapid dangerous drop in cardiac output, it is necessary to categorize depolarization waveforms on a beat-to-beat basis to accomplish rhythm classification as rapidly as possible. In this thesis, a depolarization waveform classifier based on the Lifting Line Wavelet Transform is described. It overcomes problems in existing rate-based event classifiers; namely, (1) they are insensitive to the conduction path of the heart rhythm and (2) they are not robust to pseudo-events. The …

Integration Of Micro Nano And Bio Technologies With Layer -By -Layer Self -Assembly, Dinesh Shankar Kommireddy

Doctoral Dissertations

In the past decade, layer-by-layer (LbL) nanoassembly has been used as a tool for immobilization and surface modification of materials with applications in biology and physical sciences. Often, in such applications, LbL assembly is integrated with various techniques to form functional surface coatings and immobilized matrices. In this work, integration of LbL with microfabrication and microfluidics, and tissue engineering are explored. In an effort to integrate microfabrication with LbL nanoassembly, microchannels were fabricated using soft-lithography and the surface of these channels was used for the immobilization of materials using LbL and laminar flow patterning. Synthesis of poly(dimethyldiallyl ammonium chloride)/poly(styrene sulfonate) …

The Igipi Ontological Framework: Integrating Gene Interactions With Protein Interactions, Bill Andreopoulos, Aijun An, Xiangji Huang

Faculty Publications, Computer Science

No abstract provided.

Application Of Polyelectrolyte Layer-By-Layer Nano-Assembly For Surface Modification, Encapsulation And Controlled Release, Nikhil Anil Pargaonkar

Doctoral Dissertations

In this study, we applied the traditional Electrostatic layer-by-layer (ELBL) assembly procedure to fabricate nanothin films over flat surfaces, and modify particle surfaces to influence the drug particle size, and drug release. The ELBL assembly has previously been applied to fabricate multilayer nano-scale thin films, but its ability to instantaneously influencing particle size is unique. Other unique observations such as influence on drug release as a result of polymer complexation, and thermal changes occurring during layer fabrication are recorded.

The ELBL self-assembly process was applied to produce dexamethasone particles layered with various polyelectrolyte layer combinations. These combinations were further applied …

Intravenous Polyethylene Glycol Inhibits The Loss Of Cerebral Cells After Brain Injury, Andrew O. Koob, Bradley S. Duerstock, Charles F. Babbs, Yinlong Sun, Richard B. Borgens

Weldon School of Biomedical Engineering Faculty Publications

We have tested the effectiveness of polyethylene glycol (PEG) to restore the integrity of neuronal membranes after mechanical damage secondary to severe traumatic brain injury (TBI) produced by a standardized head injury model in rats. We provide additional detail on the standardization of this model, particularly the use and storage of foam bedding that serves to both support the animal during the impact procedure and to dampen the acceleration of the brass weight. Further, we employed a dye exclusion technique using ethidium bromide (EB; quantitative evaluation) and horseradish peroxidase (HRP; qualitative evaluation). Both have been successfully used previously to evaluate …

A Dose-Response Curve For The Negative Bias Pressure Of An Intrathoracic Pressure Regulator During Cpr, Charles F. Babbs, Demetris Yannopoulos

Weldon School of Biomedical Engineering Faculty Publications

An intrathoracic pressure regulator (ITPR) is a device that can be added to the external end of an endotracheal tube to create controlled negative airway pressure between positive pressure ventilations. The resulting downward bias of the airway pressure baseline promotes increased venous return and enhanced circulation during CPR and also during hypovolemic shock. In the present study we exercised a mathematical model of the human cardiopulmonary system, including airways, lungs, a 4 chambered heart, great vessels, peripheral vascular beds, and the biomechanics of chest compression and recoil, to determine the relationship between systemic perfusion pressure during CPR and the value …

Optimal Control Theory Applied To A Difference Equation Model Of Cardiopulmonary Resuscitation, Eunok Jung, Charles F. Babbs, Suzanne Lenhart, Vladimir A. Protopoescu

Weldon School of Biomedical Engineering Faculty Publications

Objective: To apply the mathematical techniques of optimal control theory (OCT) to a validated model of the human circulation during cardiopulmonary resuscitation (CPR), so as to discover improved waveforms for chest compression and decompression that maximize the systemic perfusion pressure (SPP). Methods: The human circulatory system is represented by seven difference equations, which describe the pressure changes in systemic vascular compartments caused by chest compression. The forcing term is the intrathoracic pressure generated by the external chest compression, which is taken as the “control” variable for the system. The optimum waveform of this forcing pressure as a function of time, …

Axial Stent Strut Angle Influences Wall Shear Stress After Stent Implantation: Analysis Using 3d Computational Fluid Dynamics Models Of Stent Foreshortening, John F. Ladisa, Lars E. Olson, Douglas Anthony Hettrick, David C. Warltier, Judy R. Kersten, Paul S. Pagel

Biomedical Engineering Faculty Research and Publications

Introduction

The success of vascular stents in the restoration of blood flow is limited by restenosis. Recent data generated from computational fluid dynamics (CFD) models suggest that the vascular geometry created by an implanted stent causes local alterations in wall shear stress (WSS) that are associated with neointimal hyperplasia (NH). Foreshortening is a potential limitation of stent design that may affect stent performance and the rate of restenosis. The angle created between axially aligned stent struts and the principal direction of blood flow varies with the degree to which the stent foreshortens after implantation.

Methods

In the current investigation, we …

Validation Of Lower Limb Surrogates As Injury Assessment Tools In Floor Impacts Due To Anti-Vehicular Landmine Explosions, Ana Barbir

Wayne State University Theses

The aim of this study is to assess the ability of lower limb surrogates to predict injury due to floor impact in military vehicles during anti-vehicular (AV) landmine explosions. Most such surrogates have originally been constructed for use in automotive crash applications, where footwell intrusion is the main source of lower limb injury. Land mine explosions, however, create different loading conditions on the lower leg. Comparatively, the peak loads are higher but the durations are shorter and the loading occurs axially through the tibia, instead of the axial loading combined with foot rotation that is often observed in automotive applications. …

Microbial Quality Of Runoff Following Land Application Of Cattle Manure And Swine Slurry, Jeanette A. Thurston-Enriquez, John E. Gilley, Bahman Eghball

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Concentrations of human health-related microorganisms in runoff from agricultural plots (0.75m x 2m) treated with fresh and aged cattle manure, swine slurry and no manure (control) were determined. Three consecutive simulated rainfall events, producing 35 mm rainfall and separated by 24 h, were carried out for each plot. Fecal indicator (Escherichia coli, enterococci, Clostridium perfringens and coliphage) loads released in rainfall runoff from plots treated with fresh cattle manure, aged cattle manure and swine slurry treatments ranged from 5.52 x 10⁵ to 4.36 x 10⁹, 3.92 x 10⁴ to 4.86 x 10⁸, and 9.63 …

An Experimental Technique For Measurement Of Heat Generated During Bone Sawing, Hamid Khalili Parsa, Ger Reilly, Brendan Mccormack

Conference Papers

Orthopaedic bone cutting processes such as osteotomy and hip arthroplasty involve the cutting of one with the aid of various manual and powered cutting instruments including manual and powered bone saws. The extent of surgically induced bone necrosis at the point of the cutting tool and the bone is mainly due to the frictional heat generated by bone cutting. Bone necrosis has an impact on bone regeneration, and the rate of healing of the bone post operation. The threshold temperature for impaired regeneration of bone is in the range of 44°C to 47°C. Overheating also affects the sharpness life of …

Detection Of Microcracks During Bone Cutting Using Acoustic Emission Techniques, Ashkan Safari, Ger Reilly, Brendan Mccormack

Conference Papers

Surgeons may use a number of cutting instruments such as osteotomes and chisels to cut bone during operative procedures. The initial loading of cortical bone during the cutting process results in the formation of microcracks in the vicinity of the cutting zone with main crack propagation to failure occurring with continued loading; microcracking acts as a stimulus for main crack formation and has also been shown to occur during the propagation of the main crack. It has also been reported that Acoustic Emission (AE) is generated due to microcrack formation and crack growth, prior to, and during final fracture in …

Biophysics Of Cardiopulmonary Resuscitation With Periodic Z-Axis Acceleration Of Abdominal Compression At Aortic Resonant Frequencies, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Periodic z-axis acceleration (pGz)-CPR involves oscillating motion of a whole patient in the head-to-foot dimension on a mechanized table. The method is able to sustain blood flow and long-term survival during and after prolonged cardiac arrest in anesthetized pigs. However, the exact mechanism by which circulation of blood is created has remained unknown. Objectives: To explain the hemodynamic mechanism of pGz-CPR and to suggest theoretically useful improvements. Method: Computer modeling using a hybrid analytical-numerical approach, based upon Newton’s second law of motion for fluid columns in the aorta and vena cavae, Ohm’s law for resistive flow through vascular beds, and …

Substrate-Mediated Delivery From Self-Assembled Monolayers: Effect Of Surface Ionization, Hydrophilicity, And Patterning, Angela K. Pannier, Brian C. Anderson, Lonnie D Shea

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Gene transfer has many potential applications in basic and applied sciences. In vitro, DNA delivery can be enhanced by increasing the concentration of DNA in the cellular microenvironment through immobilization of DNA to a substrate that supports cell adhesion. Substrate-mediated delivery describes the immobilization of DNA, complexed with cationic lipids or polymers, to a biomaterial or substrate. As surface properties are critical to the efficiency of the surface delivery approach, selfassembled monolayers (SAMs) of alkanethiols on gold were used to correlate surface chemistry of the substrate to binding, release, and transfection of non-specifically immobilized complexes. Surface hydrophobicity and ionization were …

The Processing, Mechanical Properties And Bioactivity Of Zinc Based Glass Ionomer Cements, D. Boyd, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of Glass Ionomer Cements (GICs) for use in orthopaedics is retarded by the presence in the glass phase of aluminium, a neurotoxin. Unfortunately, the aluminium ion plays an integral role in the setting process of a GIC and its absence is likely to hinder cement formation. However, zinc oxide, a bacteriocide, can act both as a network modifying oxide and an intermediate oxide in a similar fashion to alumina and so ternary systems based on zinc silicates often have extensive regions of glass formation. The purpose of this research was to produce novel GICs based on calcium zinc …

Coronal Fractures Of The Distal Femoral Condyle: A Biomechanical Evaluation Of Four Internal Fixation Constructs, David J. Hak, James Nguyen, Shane Curtiss, Scott Hazelwood

Biomedical Engineering

This study evaluated different fixation methods in posterior femoral condyle coronal fractures. A standardised osteotomy was created in synthetic composite femurs and fixed with one of four methods (one 3.5 mm diameter screw, two 3.5 mm screws, one 6.5 mm screw, two 6.5 mm screws). The stiffness and mean loads to specified displacements were measured. The stiffness of two 6.5 mm screws was significantly greater than both single 3.5 mm screw (3567 versus 2584 N/mm; p = 0.0075) and double 3.5 mm screws (3567 versus 2080 N/mm; p = 0.003). There was no statistical difference in the stiffness of one …