Biomedical Engineering and Bioengineering Commons^™

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 …

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 …

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 …

Laser And Led Effects On The Proliferation Rate Of Periodontal Ligament Fibroblasts, Allen J. Job

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To compare the effectiveness of a Gallium Aluminum Arsenide (GaAlAs) diode laser and a light emitting diode (LED) on periodontal ligament fibroblast cell proliferative rates.

METHODS and MATERIALS: PDLF obtained from freshly extracted permanent teeth were cultured under standard conditions until a subconfluent monolayer was present. The next section took 5 days to complete. On day 1, the initial cell concentration of 700 uL/cm² was plated on 96-well assay plates and placed in a CO₂ incubator at 37° C for 24 hours. On day 2, cell counts were first verified using hemocytometry then were irradiated using an …

Quantification Of Long-Range Power Law Correlations Among Healthy And Pathologic Subjects Using Detrended Fluctuation Analysis And Multifractal Detrended Fluctuation Analysis, Hardick Raval

Theses

The healthy heartbeat is traditionally thought to be regulated according to the classical principle of homeostasis whereby physiologic systems operate to reduce variability and achieve an equilibrium-like state. However recent studies reveal that under normal conditions, beat-to-beat fluctuation in heart rate display the kind of long-range correlations typically exhibited by the dynamical system far away from equilibrium. In contrast, heart rate time series from patients with severe congestive heart failure show a breakdown of this long-range correlation behavior. Two different non-linear dynamic methods namely Detrended Fluctuation Analysis (DFA) and Multifractal (MF) DFA are used for the quantification of this correlation …

In Vitro Evaluation Of Human Mesenchymal Stem Cell Neural Differentiation On Tyrsine-Derived Polyarylates And Polycarbonates, Yee-Shuan Lee

Theses

Present spinal cord injury treatments cannot restore motor and sensory functions caused by the injury. These functions can return in the hopes of repairing the neural cells with a tissue engineered designed scaffold complex. The scaffold complex will include cells to repair and replace the damaged cells.

Mesenchymal stem cells (MSC) are multipotent adult stem ells that are capable of differentiating along several lineage pathways. Neural stem cell and MSC differentiating along the neural lineage bave been investigated both in vivo and in vitro depicting its feasibility. MSC for neural differentiation can be achieved by microenvironmental signaling. Substrate surface characteristics …

Quantification Of Regularity In Rr-Interval Time Series Using Approximate Entropy, Sample Entropy, And Multi-Scale Entropy, Nirvish Shah

Theses

Heart rate variability (HRV) has proven to be a useful noninvasive tool to study the neuronal control of the heart. Recently, nonlinear dynamic methods based on chaos theory and fractal dynamics have been developed to uncover the nonlinear fluctuations in heart rate. Approximate Entropy (ApEn), Sample Entropy (SampEn) and Multi-scale Entropy (MSE) are measures based on chaos theory that quantify the regularity in time series. This study has been designed to examine the ability of these measures to distinguish the RR-interval time series of normal subjects (NSR) from subjects with congestive heart failure (CHF). The study was conducted on the …

Haptic Induced Motor Learning And The Extension Of Its Benefits To Stroke Patients, Adrienne M. Coppa

Theses

In this research, the Haptic Master robotic arm and virtual environments are used to induce motor learning in subjects with no known musculoskeletal or neurological disorders. It is found in this research that both perception and performance of the subject are increased through the haptic and visual feedback delivered through the Haptic Master. These system benefits may be extended to enhance therapies for patients with loss of motor skills due to neurological disease or brain injury.

Force and visual feedback were manipulated within virtual environment scenarios to facilitate learning. In one force feedback condition, the subject is required to maneuver …

Growth Behavior Of Fibroblasts Influenced By Small Changes In Polymer Structure, Saraswathi Doddi

Theses

Polymers are a promising class of biomaterials that can be engineered to meet specific end use requirements. The order and processing history of the polymer, which would alter the molecular orientation of the material could have a significant contribution towards cellular attachment and in turn, cell growth on the particular polymer. Surface properties of the material were considered to directly influence the properties of the adherent cells including cellular growth and reorganization. The present study is aimed at comparing cell growth on polyarylates with that of polylactic acid in their original state or by introducing small changes in the surface …

Multifractal Analysis Of Heart Rate Variability Using Wavelet-Transform Modulus-Maxima Method, Chirag Jani

Theses

Physiological signals are complex and carry information of human health. Recent studies reveal that under normal conditions, the heart rate time series shows multifractal behavior. In contrast, HRV in the pathological state such as congestive heart failure exhibits more monofractal-like structure. Recent advances in the assessment of heart rate variability (HRV) uses a nonlinear dynamics approach. In this study, the main objective is to use the wavelet-transform modulus-maxima method for the multifractal analysis of the heart rate time senes.

The degree of the multifractality is defined by the singularities (a point in time series where a mathematical function is not …

Combined Effects Of Prozac And Hypothalmic Mediated Response On Masseter Muscle Activity In The Cat, Chika P. Nwaorgu

Theses

The present study tested the hypothesis that infusion of Prozac would serve to suppress defensive rage elicited from the medial hypothalamus of the cat. Cats are known to exhibit certain kind of behavior, known as the "defensive rage response" such as unsheathing of the claws, retraction of the ear and vocalization (hissing).

Three adult cats (2 males and 1 female) weighing (2.8 - 3.4 kg) were utilized during the experiments. Cannula-electrodes were implanted into the medial hypothalamus for elicitation of defensive rage behavior. EMG activity was recorded with a bipolar electrode attached to the masseter muscle to establish baseline before …

Wet-Spinning And Thermal Analysis Of Collagen Fibers Incorporating Hydroxyapatite In Mixed And Coated Form, Sandesh Nathaniel Prakash

Theses

The composition of natural bone comprises of collagen (Cg) as organic phase which acts as a matrix and inorganic calcium phosphate, particularly hydroxyapatite (HA), which is used as reinforcement. This study involved the wet-spinning of collagen fibers incorporating HA in mixed and coated form. The weight percent ratio of collagen and HA in the composite fibers was 95 to 5 respectively. HA coating on pure collagen fibers was achieved by immersing them in HA solution formed by mixing HA in water. With Thermomechanical analysis, the highest breaking point temperature was obtained for the composite fibers and the least with pure …

The Creation And Testing Of A Mock Functional Magnetic Resonance Imaging Facility For Pain Patients, Gladstone Vincent Reid

Theses

Unfamiliarity with functional Magnetic Resonance Imaging (fMRI) facilities leads to unwanted stress-related disturbances in the processing of fMRI data. A mock fMRI facility was developed to increase familiarization among subjects participating in fiviRI studies and to alleviate the time and cost of familiarizing each subject in an actual fMRI facility. A decommissioned Magnetic Resonance Imaging (MRI) unit was remodeled to visually and aurally resemble the Siemens Magnetom Allegra 3 Telsa fMRI machine currently used at the University of Medicine and Dentistry of New Jersey (UMDNJ), Newark, New Jersey. Instrumentation was developed using LabVIEW software which presented subjects with recreated sounds …

Analysis Of The Dynamics Of Vasomotion Using Laser Doppler Flow, Shruthi Raj

Bioengineering Theses - Archive

Vasomotion is a phenomenon caused by changes in the diameters of blood vessels. It is due to the contractile activity of small arteries and arterioles resulting in periodic changes of blood flow in the skin. These flow variations in the arteries are reflected by the Laser Doppler Flowmeter. The goal of the skin blood flow (blood perfusion) study is to establish a method to analyze and quantify the pattern of vasomotion as detected using Laser Doppler Flow (LDF). Spectral analysis of the LDF signal reveals the presence of periodic components in the vascular system. The study involves twelve subjects of …

Vascular Stent Analysis, Tre Raymond Welch

Bioengineering Theses - Archive

It is important for cardiologist to understand the stresses and strains the stent experiences during deployment. We created a 3-D model of the coiled stent which is exported into ANSYS creating the finite element model. The stent material is Poly-L-Lactic Acid (PLLA) fiber with a Young's modulus of 7043(MPa) and a Poisson's ratio of 0.35. A nonlinear material analysis simulates the material behavior through plastic deformation during expansion from 1(atm) to 14(atm). The von Mises stresses, principal stresses, and principal strains are analyzed to determine the yielding of the PLLA fiber. Also, the effect of different material properties including Young's …

Near Infrared Spectroscopy: A Study Of Cerebral Hemodynamics During Breathholding And Development Of A System For Hot Flash Measurement, Vikrant Sharma

Bioengineering Theses - Archive

Near Infrared (NIR) spectroscopy and imaging has become popular in research fields for the past 2-3 decades. My research focuses on the continuous wave near infrared imaging technique. The work consists of two main parts. In the first part, an existing commercial system, an LEDI (Light Emitting Diode Imager), is used to study the cerebral hemodynamics during breath holding. The aim was to evaluate the ability of an LED-based continuous wave imager to capture changes in hemodynamics occurring inside the skull induced by breath holding. The study involved 15 human subjects. It was found that the total hemoglobin concentration (in …

Dynamic Modeling Of Cerebral Blood Flow Autoregulation Using Arx And Windkessel Models, Piyush Gehalot

Bioengineering Theses - Archive

Linear lumped parameter models like ARX and Windkessel models are simple, easy to solve, and find their application in real time modeling. The present study is focused on employing single input single output ARX and Windkessel models to beat-to-beat mean arterial blood pressure (MABP, mmHg) considered as input to the model, and cerebral blood flow velocity (CBFV, cm/sec) considered as output of the model. For some models and modeling methodologies, the data consisted of cerebral perfusion pressure (CPP, mmHg, estimated from MABP) and CBFV. The data was measured from 10 healthy normal subjects while the subjects performed Valsalva maneuver with …

Biomechanical Properties Of Anterior Vaginal Wall Tissue In Post-Menopausal Women, Aradhana Bhatt

Bioengineering Theses - Archive

Cystocele repair in post-menopausal women suffering from urinary incontinence and associated vaginal prolapse is a common method of palliation. In this method, there is surgical reduction of vaginal tissue and the weak cross-sections are often supported with a synthetic sling fashioned from polymer mesh material. Some sling-supported and unsupported repairs fail over the years. The reasons for these failures are unclear, due in part to a lack of fundamental knowledge of the mechanisms associated with cystocele and vaginal prolapse. The aim of this study was to understand the mechanisms of tissue failure by biomechanical and ultrastructural studies. We take advantage …

Manure Use Planning: An Evaluation Of A Producer Training Program, Charles S. Wortmann, Richard K. Koelsch, Charles A. Shapiro, Richard L. Deloughery, David D. Tarkalson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A training program for producers in manure use planning was evaluated. The potential for runoff nutrient loss to surface water can reduced and the value of manure increased through better planning of manure use. Training was conducted throughout Nebraska in 2002 and 2003. Livestock producers who attended evaluated the event at the end of the last class. The need for and impact of the training was greater for continuing operational and maintenance skills of manure utilization that are regularly needed for strategic planning skills. We recommend that training focus primarily on operational and maintenance skills.

Microfocal X-Ray Computed Tomography Post-Processing Operations For Optimizing Reconstruction Volumes Of Stented Arteries During 3d Computational Fluid Dynamics Modeling, John F. Ladisa, Lars E. Olson, Kristina M. Ropella, Robert C. Molthen, Steven Thomas Haworth, Judy R. Kersten, David C. Warltier, Paul S. Pagel

Biomedical Engineering Faculty Research and Publications

Restenosis caused by neointimal hyperplasia (NH) remains an important clinical problem after stent implantation. Restenosis varies with stent geometry, and idealized computational fluid dynamics (CFD) models have indicated that geometric properties of the implanted stent may differentially influence NH. However, 3D studies capturing the in vivo flow domain within stented vessels have not been conducted at a resolution sufficient to detect subtle alterations in vascular geometry caused by the stent and the subsequent temporal development of NH. We present the details and limitations of a series of post-processing operations used in conjunction with microfocal X-ray CT imaging and reconstruction to …

Sequential Labelling And Acoustic Emission Analysis Of Damage Occurring In Cortical Bone During Indentation Cutting, Ger Reilly, Ashkan Safari, David Taylor, Brendan Mccormack

Conference Papers

When a surgeon uses a wedge shaped blade or an osteotome to cut cortical bone during an operative procedure the bone will fail by a process of microcracking and primary crack propagation. It has previously been observed that crack propagation is dependent on the direction of cutting relative to the main axis of the bone. It has also been observed that microcracks occurring during fracture release acoustic signals that facilitate real-time monitoring of a cutting process. In these novel studies, we labelled damage accumulation during cutting of cortical bone using sequential chelating dyes and we correlated recorded AE signals during …

Managing Phosphorus In Beef Feeding Operations, William F. Kissinger, Richard K. Koelsch, Galen E. Erickson, Terry J. Klopfenstein

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

A commercial feedlot study was conducted to determine manure nutrient flow in six feedlots representing 6,366 cattle. On average, cattle involved in this summary were yearlings (BW = 353 kg) and gained 183 kg over 123 d. It was calculated that 11.5% of the feed nitrogen and 16.9% of the feed phosphorus was retained by the animal with the remaining nutrients excreted. On average, 25.6 kg of N and 4.1 kg of P (DM basis) were excreted per fed beef animal. On average, 887 kg total manure (solids and water) were removed per finished animal (7.2 kg/animal/d) averaging 73% total …

Integrating Animal Feeding Strategies Into Cnmp Processes: Role Of Updated Asae Standard D384.2, Richard K. Koelsch, W. Powers, A. L. Sutton

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

This paper introduces the new ASAE Standard D384.2, Manure Production and Characteristics. This new standard provides an equation-based approach that integrates dry matter and nutrient intake as well as animal performance into the final estimate of total solids, nitrogen, and phosphorus excretion for seven livestock and poultry species. The manure excretion estimates of the new standard are compared with the past ASAE standard as well as other commonly used reference values for three specie groups. Significant differences in excretion are common with the new standard compared to past standards. The paper also details examples of how common industry variations in …

A New Application For Fine Ground Rubber In The Control Of Odors From Livestock Manure Storage Structures, Lakshmi Koppolu, Richard K. Koelsch, Dennis D. Schulte, Crystal Powers, Dwaine Bundy

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

The purpose of this project was to quantify the odor and gas emission benefits of a fine ground rubber cover on laboratory scale manure storage units and to evaluate the ability of a fine ground rubber cover applied to a commercial swine manure storage unit to remain intact and functional over an extended period of time. A three-inch cover of fine ground rubber reduced odors by 77 to 99 percent from the manure storage tanks over a six-week period. However, consistent reductions of NH₃ emissions were not observed and H₂S emissions from all manure storage treatments were …

Organization And Signal Processing Of The Descending Tracts In The Cervical Spinal Cord, Yanmei Tie

Doctoral Dissertations

This dissertation addresses the research for the development of spinal cord-computer interface (SCCI). The main objective of SCCI is to generate voluntary motor control signals for individuals with spinal cord injury (SCI).

In the neuroscience aspect, organization of the fibers in the descending tracts of the dorsolateral funiculus of the cervical spinal cord was investigated in cats. The spinal cord was penetrated with silicon substrate microelectrodes at 400 μm intervals in the medio-lateral direction at the C5/C6 and C6/C7 segmental borders. The stimulus consisted of a 20 ms train of charge-balanced biphasic pulses at 330 Hz. The evoked activities from …

Modeling, Design, And Validation Of Fluorescent Spherical Enzymatic Glucose Microsensors Using Nanoengineered Polyelectrolyte Coatings, Jonathan Quincy Brown

Doctoral Dissertations

In this dissertation, the modeling, design, and function of fluorescent spherical enzymatic microsensors for minimally-invasive diabetic monitoring are described. The devices reported herein are novel and their experimental construction and theoretical analysis have not been previously reported, thus laying the foundation for an intensive set of studies. These sensors are based on the encapsulation of an enzymatic fluorescent assay for glucose within hydrogel alginate microspheres with diameters on the order of tens of microns, which are of the appropriate size for intradermal implantation. A novel feature of these sensors is the use of multifunctional nanoengineered ultrathin multilayer polyelectrolyte coatings on …

Electromagnetic Measurement Of Spinal Curvature, Ronan Fitzmaurice, Ted Burke, Annraoi De Paor

Conference Papers

In this paper, we describe an original mathematical technique for calculating the position and orientation of an electromagnetic coil from a minimum of four collinear magnetic field measurements. This problem arose in the development of a system for evaluating the efficacy of inflatable back rafts designed to mitigate complications that arise from the immobilisation of patients with suspected spinal injuries on spinal boards during transport to hospital. Electromagnetic markers are attached to points of interest on the back of an immobilised test subject. Spinal curvature is then measured by passing a magnetometer underneath the board.