Biomedical Engineering and Bioengineering Commons^™

Novel Processing Of Hydroxyapatite-Zirconia Composites Using Nano-Sized Particles, Mark R. Towler, I. R. Gibson, S. M. Best

Chemical and Biochemical Engineering Faculty Research & Creative Works

A method to produce composites of hydroxyapatite (HA) with ZrO2 (Y-TZP) additions between 0 and 10 wt % at a low sinter temperature of 750 °C is presented. The method limits the amount of reaction between the HA and ZrO2. A ZrO2 loading level that would improve strength while limiting the decomposition of the HA is studied.

Hybridization Of Dna By Sequential Immobilization Of Oligonucleotides At The Air-Water Interface, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Anand Gole, K. N. Ganesh

Faculty Works

The hybridization of DNA by sequential electrostatic and hydrogen-bonding immobilization of single-stranded complementary oligonucleotides at the air-water interface with cationic Langmuir monolayers is demonstrated. The complexation of the single-stranded DNA molecules with octadecylamine (ODA) Langmuir monolayers was followed in time by monitoring the pressure-area isotherms. A large (and slow) expansion of the ODA monolayer was observed during each stage of complexation in the following sequence: primary single-stranded DNA followed by complementary single-stranded DNA followed by the intercalator, ethidium bromide. Langmuir-Blodgett (LB) films of the ODA-DNA complex were formed on different substrates and characterized using quartz-crystal microgravimetry (QCM), Fourier transform infrared …

Runoff And Soil Loss As Affected By The Application Of Manure, John E. Gilley, L. Mark Risse

Biological Systems Engineering: Papers and Publications

Manure has been used effectively to improve crop production and soil properties because it contains nutrients and organic matter. While it is generally accepted that the improved soil properties associated with manure application lead to changes in runoff and soil erosion, few studies have quantified these impacts. Water quality models used to assess watershed management and estimate total maximum daily load must accurately predict loading rates from fields where manure has been applied. This study was conducted to assemble and summarize information quantifying the effects of manure application on runoff and soil loss resulting from natural precipitation events, and to …

Direct Current Electrical Stimulation Increases The Fusion Rate Of Spinal Fusion Cages, Jeffrey M. Toth, Howard Seim, Jeffrey D. Schwardt, Wendy B. Humphrey, Joel A. Wallskog, A. Simon Turner

Biomedical Engineering Faculty Research and Publications

Study Design. A randomized experimental evaluation of direct current stimulation in a validated animal model with an experimental control group, using blinded radiographic, biomechanical, histologic, and statistical measures.

Objectives. To evaluate the efficacy of the adjunctive use of direct current stimulation on the fusion rate and speed of healing of titanium interbody fusion cages packed with autograft in a sheep lumbar interbody fusion model.

Summary of Background Data. Titanium lumbar interbody spinal fusion cages have been reported to be 90% effective for single-level lumbar interbody fusion. However, fusion rates are reported to be between 70% and 80% in patients with …

Fluid Mechanic Assessment Of The Total Cavopulmonary Connection Using Magnetic Resonance Phase Velocity Mapping And Digital Particle Image Velocimetry, Ann E. Ensley, Agnès Ramuzat, Timothy M. Healy, George P. Chatzimavroudis, Carol Lucas, Shiva Sharma, Roderic Pettigrew, Ajit P. Yoganathan

Chemical & Biomedical Engineering Faculty Publications

The total cavopulmonary connection (TCPC) is currently the most promising modification of the Fontan surgical repair for single ventricle congenital heart disease. The TCPC involves a surgical connection of the superior and inferior vena cavae directly to the left and right pulmonary arteries, bypassing the right heart. In the univentricular system, the ventricle experiences a workload which may be reduced by optimizing the cavae-to-pulmonary anastomosis. The hypothesis of this study was that the energetic efficiency of the connection is a consequence of the fluid dynamics which develop as a function of connection geometry. Magnetic resonance phase velocity mapping (MRPVM) and …

A Statewide Educational Program To Implement Comprehensive Nutrient Management Planning, Richard K. Koelsch, Charles A. Shapiro, R. Wozniak

Department of Biological Systems Engineering: Conference Presentations and White Papers

EPA and USDA NRSC have stated that the most effective way for animal feeding operations (AFO's) to minimize water quality and public health risks is to develop and implement comprehensive nutrient management plans. In response a proposed CNMP workbook has been designed to serve as an animal operation's environmental operating plan. This project will initiate field testing of the proposed Nebraska CNMP with livestock producers and advisors. It will also assist with development of supporting resources and training for educational and technical advisors.

Fuzzy Composite Programming To Combine Remote Sensing And Crop Models For Decision Support In Precision Crop Management, David D. Jones, E. M. Barnes

Biological Systems Engineering: Papers and Publications

Precision crop management is by definition a multi-objective decision-making process that must incorporate a diversity of data, opinion, preference and objective. This paper details an approach to decision making that allows users to express individual or corporate values and preferences; highlights the degree of imprecision associated with each input; highlights the degree of imprecision associated with each alternative; facilitates structuring of the decision process; reduces several levels of complex information into a single chart; allows examination of trade-off between alternatives and interests; and forces examination of inter-relationships between interest. The addition of using remote sensing data provides an efficient method …

The Effect Of Anisotrophy On The Potential Distribution In Biological Tissues And Its Impact On Nerve Excitation Simulations, Robert B. Szlavik, Hubert De Bruin

Biomedical Engineering

Presents a finite difference solution of the potential distribution associated with electrical current stimulation in an anisotropic in-homogeneous tissue environment and compare it to the isotropic case. The results demonstrate that there can be significant errors associated with the assumption of isotropic tissue properties in calculating the potential distribution along an axon in nerve excitation simulations. These errors can have a significant impact on predicted nerve fiber recruitment patterns when evaluating the efficacy of specific surface or intramuscular stimulus electrode configurations. The results of this study also suggest when a more comprehensive tissue model should be implemented in an electrode …

Autonomic Activity In Gulf War Veterans Using Heart Rate And Systolic Blood Pressure Variability, Maryann S. Fam

Theses

Heart rate variability (HRV) describes variations of heart rate and is attributed to cyclic fluctuations in autonomic tone. The different methods of heart rate variability analysis allow for a non-invasive assessment of autonomic activity. This study analyzes the heart rate variability through both frequency domain methods and joint time-frequency domain methods which were executed through the LabVJEW graphical programming language. These algorithms were utilized to assess autonomic nervous system activity in Gulf War veterans with no health complaints versus Gulf War veterans with chronic fatigue syndrome. The heart rate variability analysis was obtained from acquired measurements of heart rate and …

Drowsy Driver Data Acquisition System, Rafael Norat

Theses

This thesis focuses on detecting the drowsiness of a driver based on differentiation of the EEG signal activity between the eyes open and eyes closed states. Here, it is observed that there is a significant increase 'in a 10 Hz component of the alpha rhythm activity when the subject under test closes his / her eyes. This phenomenon was observed when electrodes were attached to the occipital region. A more desirable approach is to develop a non-intrusive measurement based on a multiturn differential coil combination utilizing a low noise high gain amplifier. The system developed here used an 80,000 turn …

Phototrophic Anaerobic Lagoons As Affected By Copper And Zinc In Swine Diets, John E. Gilley, Daniel P. Spare, Richard K. Koelsch, Dennis D. Schulte, Phillip S. Miller, Anne M. Parkhurst

Biological Systems Engineering: Papers and Publications

Odor emissions from anaerobic lagoons containing large populations of phototrophic bacteria are usually minimal. This study was conducted to determine whether copper (123 ppm) and zinc (2,310 ppm) in diets fed to weanling pigs for therapeutic purposes affect phototrophic conditions within lagoons. Column reactors containing 47 L of swine lagoon sludge and supernatant were used to represent lagoons. The reactors were placed in an environmental chamber maintained at 24° C. Copper, zinc, and control manure were added to the reactors at a volatile solids loading rate of 128 g_vs m^–3 da^–1 using a hydraulic retention time of …

Persistence Of Motor Adaptation During Constrained, Multi-Joint, Arm Movements, Robert A. Scheidt, David J. Reinkensmeyer, Michael A. Conditt, W. Zev Reymer, Ferdinando A. Mussa-Ivaldi

Biomedical Engineering Faculty Research and Publications

We studied the stability of changes in motor performance associated with adaptation to a novel dynamic environment during goal-directed movements of the dominant arm. Eleven normal, human subjects made targeted reaching movements in the horizontal plane while holding the handle of a two-joint robotic manipulator. This robot was programmed to generate a novel viscous force field that perturbed the limb perpendicular to the desired direction of movement. Following adaptation to this force field, we sought to determine the relative role of kinematic errors and dynamic criteria in promoting recovery from the adapted state. In particular, we compared kinematic and dynamic …

Biomechanical Evaluation Of Patient Transfers, Charles Costa

Theses

The purpose of this study is to identify the problem encountered when a patient with limited strength and mobility needs assistance in transferring from a wheelchair to another location.

This study took advantage of ergonomic techniques to isolate the source of stress, and limited these stresses according to the standards of the National Institute of Safety and Health Administration.

A device was developed whereby the stresses of a patient transfer were eliminated. By using a conventional wheelchair and a recliner as a starting point, effectively combining these components into a single multifunctional unit the goal of reducing stress was achieved. …

A Study Of The Parameters And Stipulations Involved In The Design Of Prosthetic Limb Socket Liners, Sally F. Shady

Theses

The objective of this thesis is to illustrate the parameters that define and characterize the elements necessary for an optimal prosthetic socket interface design. Previous studies have revealed that the industry is manufacturing materials that are causing irregularities in gait patterns and causing major discomfort for transtibial amputees. As a result, chances for recovery and rehabilitation of many patients have been greatly reduced.

This study has indicated that the success of a socket liner depends on quantitative and qualitative factors that assess the overall efficacy of an artificial limb. Quantitative analysis is observed through calculations and deviations in gait cycles, …

The Import Of Importing And Unnatural Acts: The Political Psychology Of Bioengineered Plants, Ibpp Editor

International Bulletin of Political Psychology

This article describes political psychological aspects of opposition to the importing of bioengineered plants.

Functional Infrared Imaging Of The Breast, J. Keyserlingk, P. Ahlgren, E. Yu, N. Belliveau, M. Yassa

Edward Yu

In order to re-assess the potential contribution of infrared (IR) imaging as a first-line component of a multi-imaging strategy using currently available technology, we first review the history of its introduction and clinical application, including the results of the Breast Cancer Detection Demonstration Projects (BCDDP). We then discuss experiments with a new high-resolution, computerized IR station and software program acquired by the Ville Marie Breast Center to assess IR imaging's ability to complement clinical examination and mammography in the early detection of breast cancer. Our goal is to show that high-resolution IR imaging provides additional safe, practical, and objective information …

Design Of A Fluoride Removal Water Treatment System For A Guatemalan Community: An Exercise In Global Engineering, Jason R. El Koubi

Honors Theses

No abstract provided.

Micro-Ct Image-Derived Metrics Quantify Arterial Wall Distensibility Reduction In A Rat Model Of Pulmonary Hypertension, Roger H. Johnson, Kelly L. Karau, Robert C. Molthen, Steven Thomas Haworth, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

We developed methods to quantify arterial structural and mechanical properties in excised rat lungs and applied them to investigate the distensibility decrease accompanying chronic hypoxia-induced pulmonary hypertension. Lungs of control and hypertensive (three weeks 11% O₂) animals were excised and a contrast agent introduced before micro-CT imaging with a special purpose scanner. For each lung, four 3D image data sets were obtained, each at a different intra-arterial contrast agent pressure. Vessel segment diameters and lengths were measured at all levels in the arterial tree hierarchy, and these data used to generate features sensitive to distensibility changes. Results indicate …

Effects Of Adding Sodium And Fluoride Ions To Glass Ionomer On Its Interactions With Sodium Fluoride Solution, R. W. Billington, P. C. Hadley, Mark R. Towler, G. J. Pearson, J. A. Williams

Chemical and Biochemical Engineering Faculty Research & Creative Works

This investigates the effects of the addition of Na and F ions to a glass ionomer cement in which those ions are not inherently present on its interactions with dilute (0.2%) NaF solution. Both the effect of the solution on the cement's surface morphology and the effect of the cement on the solution in terms of take up of Na⁺ and F^- and of change in pH are to be investigated. These results are to be compared to previous results obtained with glasses which contained both, one, or neither of the ions as components of their glasses. NaF …

Late Deflation Study : Hemodynamic Effects Of Iab Timing In Humans, Manal Morcos

Theses

Conventional IABP timing deflates 100% of the balloon volume before the onset of left ventricular ejection and has been well established in the literature as a safe and effective method. Yet, recent studies suggest that deflation of the IAB at or near the onset of systole improve myocardial efficiency (Kern, 1999, 1129). To test whether deflation of the JAB at a later deflation time reduces left ventricular workload and enhances coronary perfusion, four timing methods were evaluated in 20 patients: T₁ (100% JAB volume deflated before onset of ejection), T₂ (60% IAB volume deflated before and 40% volume …

A Study Of Factors Affecting Cardiovascular Reactivity, Andrew Gill Ventura

Theses

This pilot study was conducted to determine what affects the cardiovascular reactivity of different people. Variables such as the order of stress-inducing and relaxing activities, performing multiple tasks on different days, personality, familial history of diseases, and general health were investigated as to their effects, if any, on cardiovascular reactivity.

Ten healthy, normal male subjects, aged 18 - 33 years, volunteered to be subjected to studies on three experimental days, the first one being for gathering information. On the second and third days, the subjects performed the following activities: mental arithmetic, numeric repetition, 10 breaths-per-minute (bpm) paced-breathing, and normal breathing, …

Investigation Of The Relevance Of Heart Rate Variability Changes After Heart Transplantation, Sheeba Arnold

Theses

Heart transplantation has become an established treatment for end-stage heart disease. However, the shortage of donor organs is a major problem and long-term results are limited by allograft rejection. Heart rate variability (HRV) has emerged as a popular noninvasive research tool in cardiology. Analysis of HRV is regarded as a valid technique to assess the sympathovagal balance of the heart. The primary goal of this study was to investigate the relevance of heart rate variability changes after heart transplantation. It was found that spectral analysis of HRV is useful in detecting rejection episodes. Heart transplantation leaves the donor heart denervated. …

Development And Testing Of A Simulated Closed Loop Drug Delivery System For Chf Patients Under Milrinone Administration, Runa Shah

Theses

The purpose of this thesis project is the development and testing of a simulated closed loop drug delivery (CLDD) system that consists of a pharmacokinetic, physiological, and feedback-controlling model. The focus of this study is on the control of milrinone inflision to maintain cardiac output at desired setpoint range for patients suffering from congestive heart failure (CHF). The simulated CLDD system is written in VisSim dynamic simulation language for an IBM-compatible PC.

Milrinone pharmacokinetics are represented by a three compartment model. The physiological model consists of the cardiovascular system model linked to the pharmacodynamic submodel of milrinone. The feedback-controlling model …

Dwell Fatigue I : Damage Mechanisms, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

The mechanisms controlling deformation and failure under high temperature creep-fatigue conditions of materials are examined in this paper. The materials studied are solder alloys, copper alloys, low alloy steels, stainless steels, titanium alloys, and Ni-based alloys. The deformation and failure mechanisms were different (fatigue, creep, oxidation and their interactions) depending upon test and material parameters employed. Deformation mechanisms, such as cavity formation, grain boundary damage, intergranular (IG) and transgranular (TG) damage, oxidation, internal damage, dislocation cell concentration, and oxide mechanisms are very important in order to gain more knowledge of fatigue behavior of materials. The observed mechanisms can be categorized …

Bottom-Up Design Of Artificial Neural Network For Single-Lead Electrocardiogram Beat And Rhythm Classification, Srikanth Thiagarajan

Doctoral Dissertations

Performance improvement in computerized Electrocardiogram (ECG) classification is vital to improve reliability in this life-saving technology. The non-linearly overlapping nature of the ECG classification task prevents the statistical and the syntactic procedures from reaching the maximum performance. A new approach, a neural network-based classification scheme, has been implemented in clinical ECG problems with much success. The focus, however, has been on narrow clinical problem domains and the implementations lacked engineering precision. An optimal utilization of frequency information was missing. This dissertation attempts to improve the accuracy of neural network-based single-lead (lead-II) ECG beat and rhythm classification. A bottom-up approach defined …

The Influence Of Poly(Acrylic Acid) Molar Mass On The Properties Of Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Sinead Kenny, Robert G. Hill, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The influence of poly (acrylic acid) molar mass was investigated on cements formed from zinc oxide-apatite mixtures at three aging times: one, seven and 28 days. Cements based on both hydroxyapatite and fluorapatite were investigated. The compressive strength, un-notched fracture strength and fracture toughness increased markedly with poly (acrylic acid) molar mass. The fracture toughness and un-notched fracture strength increased with aging time for the two highest molar mass cements but decreased with time for the two lowest molar mass cements. The greater chain entanglement density present in the higher molar mass cements is thought to contribute significantly to the …

A Coupling Method Of A Homotopy Technique And A Perturbation Technique For Non-Linear Problems, Ji-Huan He

Ji-Huan He

In this paper, a coupling method of a homotopy technique and a perturbation technique is proposed to solve non-linear problems. In contrast to the traditional perturbation methods, the proposed method does not require a small parameter in the equation. In this method, according to the homotopy technique, a homotopy with an imbedding parameter p3[0, 1] is constructed, and the imbedding parameter is considered as a &&small parameter''. So the proposed method can take full advantage of the traditional perturbation methods. Some examples are given. The results reveal that the new method is very e!ective and simple. ( 1999 Elsevier Science …

Fate And Behavior Of Lead In Soils Planted With Metal-Resistant Species (River Birch And Smallwing Sedge), S. P. Klassen, J. E. Mclean, P. R. Grossl, Ronald C. Sims

Biological Engineering Faculty Publications

Phytoremediation of metal-contaminated soils requires an understanding of the interactions between metal-tolerant plant species and soil chemical properties controlling the bioavailability of metals. We conducted controlled laboratory studies to investigate the effects that river birch (Betula occidentalis Hook.) and smallwing sedge (Carex microptera Mack.) had on the fate and behavior of Pb in a contaminated soil (3000 mg Pb/kg) and tailings (13 000 mg Pb/kg) collected from an abandoned mining site in Utah. Significant Pb accumulation in aboveground tissue was observed in smallwing sedge (≥1000 mg/kg dry wt.) in both the soil and tailings, but Pb was primarily excluded by …

Efficacy Of Interposed Abdominal Compression-Cardiopulmonary Resuscitation (Cpr), Active Compression And Decompression-Cpr, And Lifestick Cpr: Basic Physiology In A Spreadsheet Model, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

This study was undertaken to understand and predict results of experimental cardiopulmonary resuscitation (CPR) techniques involving compression and decompression of either the chest or the abdomen. Simple mathematical models of the adult human circulation were used. Assumptions of the models are limited to normal human anatomy and physiology, the definition of compliance (volume change/pressure change), and Ohm’s law (flow = pressure / resistance). Interposed abdominal compression-CPR, active compression and decompression of the chest, and Lifestick CPR, which combines interposed abdominal compression and active compression and decompression, produce, respectively, 1.9-, 1.2-, and 2.4- fold greater blood flow than standard CPR and …

Performance Tests Of Three-Point Mounted Implement Guidance Systems: Ii. Results, Michael F. Kocher, Michael B. Smith, Robert D. Grisso, Linda J. Young

Biological Systems Engineering: Papers and Publications

Side-shift and disk-steer implement guidance systems were tested for differences in performance during cultivation on fields with 0 and 5% side slope. Test speeds were slow (4.8 km/h, 3 mph) and medium (8.0 km/h, 5 mph). Test path shapes included a tractor ramp, implement ramp, sine and curve. Performance measures included tractor positional error, implement positional error, torque from side forces on the cultivator non-swiveling coulters, and travel speed. Relatively few significant differences between guidance systems were detected, and most of those involved interaction with path shape. Therefore, no clear conclusion could be reached indicating one guidance system was better …