Engineering Commons^™

3d Micro-Ct For Functional Genomics, R. H. Johnson, Robert C. Molthen, Christopher C. Hanger, Kelly Lynn Karau, Steven Haworth, Christopher Dawson

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Mri Techniques For Cardiovascular Imaging, Roderic I. Pettigrew, John N. Oshinski, George P. Chatzimavroudis, W. Thomas Dixon

Chemical & Biomedical Engineering Faculty Publications

Over the last several years, cardiovascular MRI has benefited from a number of technical advances which have improved routine clinical imaging techniques. As a result, MRI is now well positioned to realize its longstanding promise of becoming the comprehensive cardiac imaging test of choice in many clinical settings. This may be achieved using a combination of basic advanced techniques. In this overview, the basic cardiac MRI techniques which are clinically useful are reviewed, and the recent technical advances which are clinically promising are described. These advances include routine black blood and cine bright blood techniques that are high speed (slice), …

The Relationship Between Basic Multicellular Unit Activation And Origination In Cancellous Bone, C. J. Hernandez, S. J. Hazelwood, R. B. Martin

Biomedical Engineering

Activation frequency is often used as a measure of basic multicellular unit (BMU) activity in cancellous bone. However, activation frequency expresses the rate of BMU appearance in a histologic slide and not the rate of origination, which is a more physiologic indicator of remodeling activity and is necessary for the development of BMU-level bone remodeling simulations. Using identical assumptions to those for calculating the activation frequency, it is shown that the origination frequency in cancellous bone is equal to the activation frequency divided by the total distance traveled by the BMU and its width.

A Defect In Interleukin 12-Induced Activation And Interferon Gamma Secretion Of Peripheral Natural Killer T Cells In Nonobese Diabetic Mice Suggests New Pathogenic Mechanisms For Insulin-Dependent Diabetes Mellitus., Marika Falcone, Brian Yeung, Lee Tucker, Enrique Rodriguez, Nora Sarvetnick

Journal Articles: Regenerative Medicine

The function of natural killer T (NKT) cells in the immune system has yet to be determined. There is some evidence that their defect is associated with autoimmunity, but it is still unclear how they play a role in regulating the pathogenesis of T cell-mediated autoimmune diseases. It was originally proposed that NKT cells could control autoimmunity by shifting the cytokine profile of autoimmune T cells toward a protective T helper 2 cell (Th2) type. However, it is now clear that the major function of NKT cells in the immune system is not related to their interleukin (IL)-4 secretion. In …

A Thin-Film Micromanufactured Oxygen Microelectrode, James Clay Mcguyer Jr.

Doctoral Dissertations

The methods for production of recessed oxygen microelectrodes developed by Whalen, et al. (1967) and improved upon by Linsenmeier, et al. (1987) are dated production methods by the standards of sensor production of the current time. The production process for this type of polarographic oxygen sensing electrode has remained unchanged for over 10 years, and is a time consuming, extremely low-yield process. The goal of this project has been to use the techniques of micromanufacturing available at the Institute for Micromanufacturing at Louisiana Tech University to construct a recessed oxygen microelectrode with a batch process that has higher yield than …

Toward Designing The Optimal Total Cavopulmonary Connection: An In Vitro Study, Ann E. Ensley, Patricia Lynch, George P. Chatzimavroudis, Carol Lucas, Shiva Sharma, Ajit P. Yoganathan

Chemical & Biomedical Engineering Faculty Publications

Background. Understanding the total cavopulmonary connection (TCPC) hemodynamics may lead to improved surgical procedures which result in a more efficient modified circulation. Reduced energy loss will translate to less work for the single ventricle and although univentricular physiology is complex, this improvement could contribute to improved postoperative outcomes. Therefore to conserve energy, one surgical goal is optimization of the TCPC geometry. In line with this goal, this study investigated whether addition of caval curvature or flaring at the connection conserves energy.

Methods. TCPC models were made varying the curvature of the caval inlet or by flaring the anastomosis. …

Quantification Of Pulmonary Arterial Wall Distensibility Using Parameters Extracted From Volumetric Micro-Ct Images, Roger H. Johnson, Kelly Lynn Karau, Robert C. Molthen, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

Stiffening, or loss of distensibility, of arterial vessel walls is among the manifestations of a number of vascular diseases including pulmonary arterial hypertension. We are attempting to quantify the mechanical properties of vessel walls of the pulmonary arterial tree using parameters derived from high-resolution volumetric x-ray CT images of rat lungs. The pulmonary arterial trees of the excised lungs are filled with a contrast agent. The lungs are imaged with arterial pressures spanning the physiological range. Vessel segment diameters are measured from the inlet to the periphery, and distensibilities calculated from diameters as a function of pressure. The method shows …

Wide Tires, Narrow Tires, Leonard L. Bashford, Michael F. Kocher, Todd S. Tibbetts

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Tractive performance comparisons among five different size tires were made on two different surface conditions, a wheat stubble field and a tilled wheat stubble field. Radial 18.4R46, 20.8R42 and 710/70R38 radial tires; and bias 750/65-38 and 850/55-42 tires were used. Instrumentation to evaluate tractive performance was installed on a two-wheel drive and a mechanical front wheel drive agricultural tractor. Axle torques, drawbar pull, travel speed, and engine rpm were recorded for a series of drawbar pulls on the two soil surfaces. Tractive performance evaluations among the tires were made by comparing the relationships of dynamic traction ratio to slip, tractive …

Analysis Of Long-Term Heart Rate Variability Using Labview, Daniel Yang

Theses

Long-term heart rate variability measurement is important in understanding the activities of the autonomic nervous system. Many methods and implications of long-terrn HRV were available in the literature. The first two studies focused on two data analysis techniques that were used on a normal subject. The first study focused on the 1/f fluctuations. For this analysis, three 1 1h heart rate variability data sets were collected with the Polar Vantage NV. A LabVIEW program was used to calculate the power spectrum of the heart rate, and then the 1/f line was calculated by taking the log of the power spectrum …

Measurements Of The Effects Of Colored Light On The Body, Lynne Hendrickson

Theses

Colored light is used in movies, restaurants, and other situations to create particular environments. It creates a mood and sets a stage for specific events.

This study used colored light to create relaxation and stress in order to evaluate physiological reactions in the human body. In all four studies of this paper, EEG, EKG, and peripheral blood flow were recorded and observed and in the latter two studies peripheral temperature and conductance were also recorded. An audio stressor was introduced in the first three studies to evaluate the stability of the altered mood of the individuals.

Considerable mood alterations were …

Computer Automated Experimentation For The Control And Assessment Of The Classically Conditioned Eyeblink Response, Michael Terrence Bergen

Theses

The use of the classically conditioned eyeblink response, a form of associative learning, is a growing method of experimentation in modem science. This type of associative learning, has many features that make it useful for applications in the study of specific neurological functions. The goal of this project was to design and implement a software system for the automated control and on-line evaluation of a classical conditioning experiment for use with human subjects. A program was developed in the LabVIEW programming environment by National Instruments. Basic hardware components produce acoustic signals, deliver airpuffs, and sense and condition physiological responses. Safety …

Nutrient Balance On Nebraska Livestock Confinement Systems, Richard K. Koelsch, Gary Lesoing

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Managing the environmental risk associated with livestock production is a significant challenge. Nitrogen and phosphorus are commonly implicated as the sources of ground and surface water quality problems associated with livestock production. The degree of imbalance between these nutrient inputs and the managed nutrient outputs for a livestock operation defines the magnitude of potential environmental risk and provides insight as to the underlying causes of these challenges. A nitrogen and phosphorus balance was constructed for 33 Nebraska confinement livestock operations. Twenty-five and 17 of these operations experienced significant nitrogen and phosphorus imbalances, respectively (50% more nutrient inputs than outputs). Nutrient …

Genetic Transformation And Regeneration Of Plants, Vincent Lee C. Chiang, Chung-Jui Tsai, Gopi K. Podila

Michigan Tech Patents

An Agrobacterium-mediated transformation and regeneration method for plants including a transformation method to produce transgenic plants with an altered lignin composition.

The Effect Of Stimulus Current Pulse Width On Nerve Fiber Size Recruitment Patterns, Robert B. Szlavik, Hubert De Bruin

Biomedical Engineering

There have been theoretical studies presented that postulate a change in the stimulus current amplitude required to recruit nerve fibers with different stimulus current pulse widths. Based on these theoretical predictions, it has been suggested that the stimulus pulse width parameter may be used to selectively recruit fibers of different sizes and that this selectivity should increase with increasing distance from the stimulus electrode. In this paper, a simulation study of the recruitment patterns of a population of motor nerve fibers with a histologically accurate fiber diameter distribution is presented. Nerve fiber excitation simulations coupled with a time varying field …

In Vivo Electrical Stimulation Of Motor Nerves, Robert B. Szlavik

Biomedical Engineering

Stimulus waveform parameters and stimulation protocols are fundamental to the use of electrical stimulation in medical applications. This thesis presents new simulation and experimental procedures that for the first time can quantify the effects on nerve fiber recruitment patterns of variable stimulus waveform parameters, such as pulse width and changes in the stimulation protocol with respect to electrode orientation. The study of the effect of variable electrical stimulus waveform parameters and stimulation protocols is important from the perspective of therapeutic and diagnostic medicine. Variations in the stimulus waveform such as stimulus pulse width have been shown to offer some promise …

Phosphorus And Nitrogen In Runoff Following Beef Cattle Manure Of Compost Application, Bahman Eghball, John E. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Manure or compost from beef cattle feedlots can be an excellent sources of nutrients and organic matter when added to soils, but they can also pollute runoff. We determined the effects of simulated rainfall on runoff losses of P and N, and EC and pH following application of manure and compost to a Sharpsburg silty clay loam (fine smectitic, mesic Typic Argiudoll) soil having grain sorghum [Sorghum bicolor (L.) Moench] and winter wheat (Triticum aestivum L.) residues. Manure, compost, and fertilizer were applied to no-till fields at rates required to meet N or P requirements for corn ( …

Anatomy Of Soft Tissues Of The Spinal Canal, Hogan Quinn, Jeffrey M. Toth

Biomedical Engineering Faculty Research and Publications

Background and Objectives.

Important issues regarding the spread of solutions in the epidural space and the anatomy of the site of action of spinal and epidural injections are unresolved. However, the detailed anatomy of the spinal canal has been incompletely determined. We therefore examined the microscopic anatomy of the spinal canal soft tissues, including relationships to the canal walls.

Methods.

Whole mounts were prepared of decalcified vertebral columns with undisturbed contents from three adult humans. Similar material was prepared from a macaque and baboon immediately on death to control for artifact of tissue change after death. Other tissues examined included …

Detection Of Changes In Lung Tissue Properties With Multiple-Indicator Dilution, David L. Roerig, Said H. Audi, John H. Linehan, Gary S. Krenz, S. B. Ahlf, W. Lin, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

We evaluated the potential utility of a group of indicators, each of which targets a particular tissue property, as indicators in the multiple-indicator dilution method to detect and to identify abnormalities in lung tissue properties resulting from lung injury models. We measured the pulmonary venous outflow concentration vs. time curves of [¹⁴C]diazepam, ³HOH, [¹⁴C]phenylethylamine, and a vascular reference indicator following their bolus injection into the pulmonary artery of isolated perfused rabbit lungs under different experimental conditions, resulting in changes in the lung tissue composition. The conditions included granulomatous inflammation, induced by the intravenous injection of …

Effect Of Postural Tilt On The Autonomic Nervous System In Gulf War Veterans, Shrenik Dagli

Theses

Time-frequency signal representations characterize signals over a joint time-frequency plane. They combine time-domain and frequency-domain analysis to yield a potentially more revealing picture of the temporal localization of a signal spectrum. Time-frequency distributions (TFDS) of signals map a one-dimensional function of time, x (t), into a two-dimensional function of time and frequency, p(t, f). Most TFDs are "time-varying representations' which are similar conceptually to a musical score with time running along one axis and frequency along the other axis.

Many Gulf War Veterans complained of symptoms like unexplainable tiredness. This condition is known as the Gulf War Syndrome. The purpose …

In Situ Aortic Root In Vitro Testing Of The Stented And Stenless Porcine Aortic Heart Valves, Sean Parker

Theses

Background - The stent, Delrin® support frame, for porcine heart valves has been blamed for reduced durability of these valves due to the additional stress caused by the relative stiffness of the stent. There is a tendency among surgeons to do away with the stent in the aortic position and use porcine stentless valves which are sewn directly in the aortic position after removing diseased valve. These stentless valves are extremely difficult to test and no appropriate holder has been designed for this purpose. New approach for in vitro testing of these valves has been developed at Sheihigh, Inc., Millburn …

Role Of Sympathovagal Imbalance In Syncope Using Heart Rate Variability Analysis, Jayadeep Krishnah Unni

Theses

One of the common and challenging problems confronting the physician in clinical practice is recurrent syncope. Despite extensive evaluations, the causes of these cases Of syncope are not found in more than 40% of the patients.

It is thought that most patients who experience unexplained syncope do so because of transient, unpredictable episodes of vasovagally mediated hypotension and bradycardia. It is hypothesized that impaired inhibition of parasympathetic tone during stress accompanies the development of syncope. Head-up tilt table testing reportedly provokes vasovagal episodes effectively in susceptible persons.

This study attempts to explain the role played by the sympathetic and parasympathetic …

Computer Simulation Of Cerebrovascular Responses During Induced Hypotension, John A. Schalago

Theses

The purpose of this project was to develop a computer model of cerebrovascular hemodynamics interacting with a pharmacodynamic drug model to examine the effects of three commonly used anti-hypertensive drugs upon intracranial pressure and cerebral blood flow. The model is used to predict cerebrovascular response during the administration of commonly used anti-hypertensive agents.

The mathematical model of intracranial hemodynamics is a seven compartment constant volume system. A series of resistances relate blood and cerebrospinal fluxes to pressure gradients between compartments. Arterial, venous and tissues compliance are included. Autoregulation is modeled by transmural pressure-dependent arterial-arteriolar resistance. The effects of three drugs …

Z-Protected Glutamic Acid-Based Biodegradable Thermoplastic And Thermosetting Polyesters: Synthesis And Characterization, R. M. Tadros, Hossein Noureddini, Delmar C. Timm

Papers in Biomaterials

Biodegradable polymers were formed from N-benzyloxycarbonyl-L-glutamic acid with the comonomers ethylene glycol, diglycidyl ether of 1,4-butanediol, and diglycidyl ether of bisphenol A. The three polymers were a linear and a cross-linked heterochain polyester and a cross-linked polyester that contained aromatic units within its network chains. The thermoplastic resin and the soluble fractions for the thermosetting resins were characterized by gel permeation chromatography. Conversions for carboxylic acid were determined by titrations. A quality, 22,000 molecular weight thermoplastic resin was formed. The two thermosets were cured past their gel points. Gelation analysis revealed that the relative rate constants for the sequential oxirane/acid …

Multifield Spectral Analysis Of Human Respiratory Sounds, John William Ray Jr.

Doctoral Dissertations

Computer analysis of human respiratory sounds (phonopneumography) has been attempted since the 1960s with poor results. Steady research efforts by numerous researchers have failed to yield a practical diagnostic tool to replace the physician and the stethoscope. This has been the result of the high degree of variability in proposed analysis parameters from subject to subject.

The purpose of this research is to examine a new approach to phonopneumography by comparing multiple lung fields of the same subject for the same breath in order to develop the diagnostic parameters. This approach has the advantage of allowing the subject to provide …

The Use Of Recombinant Human Bone Morphogenetic Protein 2 (Rhbmp-2) To Promote Spinal Fusion In A Nonhuman Primate Anterior Interbody Fusion Model, Brian P. Hecht, Jeffrey S. Fischgrund, Harry N. Harkowitz, Lori Penman, Jeffrey M. Toth, Ali Shirkhoda

Biomedical Engineering Faculty Research and Publications

Study Design. A study on the efficacy of recombinant human bone morphogenetic protein 2 (rhBMP-2) in a nonhuman primate anterior interbody fusion model.

Objectives. To investigate the efficacy of rhBMP-2 with an absorbable collagen sponge carrier to promote spinal fusion in a nonhuman primate anterior interbody fusion model.

Summary of Background Data. RhBMP-2 is an osteoinductive growth factor capable of inducing new bone formation in vivo. Although dosage studies using rhBMP-2 have been performed on species of lower phylogenetic level, they cannot be extrapolated to the primate. Dosage studies on nonhuman primates are essential before proceeding with human primate application. …

Genetic Engineering Of Wood Color In Plants, Vincent Lee C. Chiang, Chung-Jui Tsai, Gopi K. Podila

Michigan Tech Patents

The invention relates to genetically engineering the wood color of woody plants by incorporation of the lignin pathway gene O-methyltransferase into the genome of the plants.

Implant Pre-Treated For Reducing The Generation Of Wear Particulates, David A. Pienkowski, Kwon-Yong Lee

Biomedical Engineering Faculty Patents

A method is provided for reducing the amount of wear particulates generated by a total joint orthopaedic implant. The implant consists of two matched articulating components wherein at least one of the components is made of polymer or other material with similar physical properties. The method includes the steps of placing the total joint orthopaedic implant in a fluid bath and articulating the implant in the fluid bath for at least 1,000 cycles. The articulation may be performed in three stages. In the first, the implant is articulated under a load of substantially 0.1-500 Newtons with sliding speeds of substantially …

Liquid-Phase Catalytic Oxidation Of Unsaturated Fatty Acids , Hossein Noureddini, M Kanabur

Papers in Biomaterials

Liquid-phase catalytic oxidation of oleic acid with hydrogen peroxide in the presence of various transition metal/metal oxide catalysts was studied in a batch autoclave reactor. Azelaic and pelargonic acids are the major reaction products. Tungsten and tantalum and their oxides in supported and unsupported forms were used as catalysts. Alumina pellets and Kieselguhr powder were used as supports for the catalysts. Tungsten, tantalum, molybdenum, zirconium, and niobium were also examined as catalysts. Tertiary butanol was used as solvent. Experimental results concluded that tungsten and tungstic oxide are more suitable catalysts in terms of their activity and selectivity. The rate of …

Model And Clinical Device Development For Noninvasive Diagnosis Of Low Back Pain And Dysfunction, Ravi Patraju

Theses

Millions of people suffer from acute or chronic low back pain. In order for proper treatment to be administered, a patient must receive an accurate diagnosis. Therefore, it is critical to develop an objective model to measure the motion and any dysfunction of a patient's low back. Only then can a physician effectively implement the correct therapy and measure its effectiveness through follow-up to minimize or eliminate low back pain.

Numerous cadaveric, active and passive studies have been done to understand the mechanics of low back disorders. However, only living human subjects suffer from low back pain and therefore cadaveric …

The Role Of Surface Roughness For Implant Incorporation In Bone, A. Wennerberg

Cells and Materials

A careful topographical characterization is important for reliable interpretation of the role of implant surface roughness in bone incorporation. In this paper, the currently available measuring instruments and evaluation techniques are described and discussed first, than literature on the role of surface roughness for cell and bone tissue reactions in vitro and, with special emphasis, the in vivo studies are reviewed. Finally, the results from a series of the authors own animal studies evaluating screw-shaped implants with different surface roughnesses are summarized. The results demonstrated firmer bone fixation for blasted implants than for turned ones. A blasted surface with an …