Biomedical Engineering and Bioengineering Commons^™

Development Of An Experimental Model To Quantify Lumbar Spine Kinematics During Military Seat Ejection, Steven George Storvik

Master's Theses (2009 -)

The initial phase of a military ejection sequence exerts substantial axial loads on the spinal column. Eccentric inertial loading on the thoracolumbar spine can lead to injury. Most serious injuries due to ejection are in the form of a vertebral fracture, most commonly occurring at the thoracolumbar junction. The objective of the current study was to understand characteristics of a military seat ejection by employing an experimental model designed to simulate the boost or in-rail phase. The model incorporates realistic boundary conditions and is capable of quantifying metrics associated with injury tolerance such as applied accelerations and resultant loads and …

Using Modeling And Simulation To Improve Oral Health Services Delivery In Hampton Roads, Virginia, Mohammad J. Alzahrani

Health Services Research Dissertations

The purpose of this study is to examine the system performance in delivering oral health services in a public health district based on the Conceptual Framework to Measure Performance of the Public Health System (PHS). Using modeling and simulation, a predictive model based on the conceptual framework dimensions: mission, structural capacity, processes, and outcomes was developed to predict the performance of public health district in delivering oral health services.

This is a retrospective longitudinal study. The main objective of this study is to use a modeling and simulation approach to predict the performance of public health district dental clinic in …

Statistical Optimizations Of Muscle Action Potentials Based On Modeling And Analysis Of Ion Channel Dynamics, Gyutae Kim

Electrical & Computer Engineering Theses & Dissertations

An Electromyogram (EMG) is an electrical signal, which is measured from a skeletal muscle during voluntary and involuntary contractions. EMGs are useful in interpreting pathological states of the musculoskeletal system. In particular, EMGs offer valuable information concerning the timing of muscular activity and its relative intensity. Various EMG models have developed with many different purposes from a pure mathematical model to a pattern structure model [17,46]. Sophisticated EMG models are necessary to examine the effects of small changes in muscular morphology and activities [46]. Due to the crucial importance of EMG models, all factors in the model should be precise …

Noninvasive Imaging Of The Human Rod Photoreceptor Mosaic Using A Confocal Adaptive Optics Scanning Ophthalmoscope, Alfredo Dubra, Yusufu N. Sulai, Jennifer L. Norris, Robert F. Cooper, Adam M. Dubis, David R. Williams, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

The rod photoreceptors are implicated in a number of devastating retinal diseases. However, routine imaging of these cells has remained elusive, even with the advent of adaptive optics imaging. Here, we present the first in vivo images of the contiguous rod photoreceptor mosaic in nine healthy human subjects. The images were collected with three different confocal adaptive optics scanning ophthalmoscopes at two different institutions, using 680 and 775 nm superluminescent diodes for illumination. Estimates of photoreceptor density and rod:cone ratios in the 5°–15° retinal eccentricity range are consistent with histological findings, confirming our ability to resolve the rod mosaic by …

Brain-Related Chronic Pain Disorder Diagnosis And Assessment Method, Jeffrey Hargrove

Mechanical Engineering Patents

A method for diagnosing and assessing a brain-related chronic pain disorder. The method includes assessing a subject's brain function, deterrnining the probability that a subject is suffering from chronic pain as a result of an abnormal brain function condition by obtaining a quantitative assessment of the subject's brain function, and making a statistical comparison between the subject's quantitative brain function assessment and either a database of quantitative assessments of the brain functions of normal, healthy individuals, or a database of quantitative assessments of the brain functions of individuals known to have been suffering from chronic pain as a result of …

Comparing Fbg And Pcf Force Sensors In A Laparoscopic Smart Surgical Scissor Instrument, Dean Callaghan, Ginu Rajan, Mark Mcgrath, Eugene Coyle, Yuliya Semenova, Gerald Farrell

Conference Papers

This paper presents a sensorized laparoscopic surgical scissor instrument using both a fiber Bragg grating (FBG) and a tapered photonic crystal fiber (PCF) as force sensors. The sensors are located on the blades for the detection of interaction forces generated between the instrument and tissue during cutting. The force sensitivity of each sensorized blade is examined. Results show that the scissor blade-PCF sensor arrangement outperforms the blade with the FBG during static loading calibration experimentation. Moreover, experiments show that the PCF based arrangement is less sensitive to temperature effects than its FBG counterpart. This negates the need for additional temperature …

The 4+1 Program And Distance Learning Meeting Objectives And Outcomes, Daniel W. Walsh, Lanny Griffin, Robert S. Crockett

Biomedical Engineering

Graduate engineering education is a key to the maintenance of U.S. competitiveness in the world market. The world has been an extremely dynamic engine during the last fifty years, and we have witnessed a dramatic change in the world order. The change has been evolutionary in many cases, but events in Eastern Europe, the Middle East and the erstwhile Soviet Union are only slightly less cataclysmic than the Second World War. In a world where strength is measured in terms of the financial resource, the technological ability and the intellectual capability of a populace Japan, China, India and the EEC …

Review Of Gasoline, Diesel, And Ethanol Biofuels From Grasses And Plants, By Ram B. Gupta And Ayhan Demirbas., Adam J. Liska

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A new book on the production of biofuels by Gupta and Demirbas provides technical insight into the conversion processes that could provide a range of domestic fuels from plant materials to substitute for foreign oil. It focuses primarily on conversion processes for production of cellulosic ethanol, Fischer-Tropsch diesel, pyrolysis bio-oil, and hydrothermal biocrude from biomass resources, as well as "first-generation" grain ethanol and biodiesel from vegetable oil. In addition to a detailed summary of these chemical processes, the book provides a briefer treatment of related matters such as biofuel policy, economics, and environmental issues.

Surgical Cutting And Ablation By Energy Based Devices: Principles And Applications, Garrett Mcguinness, Joseph A. Mcgeough, Graham Gavin, Brendan O'Daly

Conference Papers

Advances in ultrasound, radiofrequency, and water jet systems are facilitating their increased use in new medical ablation or cutting applications in fields as diverse as cardiology, orthopaedics, ophthalmology, dermatology, oncology and neurosurgery. These methods involve controlled alteration or destruction of tissues via the application of thermal, electrical or kinetic energy. This market segment is characterised by advanced devices capable of heating or cooling tissue from -200°C to 400°C, or inducing vibrations of up to 60 kHz to cause tissue damage. The medical conditions targeted primarily pertain to chronic and age-related diseases, but elective and cosmetic procedures are also addressed. Medical …

Optimization Of A Tri-Layered Vascular Graft: The Influence Of Cellular And Mechanical Properties, Michael Mcclure

Theses and Dissertations

Electrospinning is a polymer processing technique which allows for the production of nano to micro size fibers and scaffolds which can be composed of numerous synthetic biodegradable materials and natural biopolymers. Natively, elastin and collagen are the main components of vascular tissue. Arranged in a tri-layered structure, they create a specific mechanical environment that can withstand the rigors of circulation. The goal of this study was to develop a mechanically ‘biomimicking’ vascular graft composed of three distinct layers through the process of electrospinning. We hypothesize that the use of bioactive agents such as elastin, collagen, and silk to supplement poly(caprolactone) …

An Argument For The Importance Of Material Property Characterization Of Hydrogels, J. M. Zuidema, R. J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Hydrogels are being fabricated for use in many tissue engineering applications. In order to advance the field, material properties must be characterized to determine the most desirable attributes. The data presented shows the importance of both surface charge and mechanical properties on dorsal root ganglia neurite extension. © 2011 IEEE.

Aluminium-Free Glass Polyalkenoate Spinal Cements, A. W. Wren, N. M. Cummins, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Addition of Yitanium increased the Wt & St and the sf strength of these cements compared to the control (BT 101). © 2011 IEEE.

Fabrication And Characterization Of A Hydrogel Containing Electrospun Fibers, C. J. Rivet, R. J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Electro spun an fibers hydrogels are two focal points of research within the biomaterial's community. The electrospinning process allows for fabrication of nanoscale, aligned topography and has been shown to direct cellular migration and outgrowth. Hydrogels exhibit benefits over traditional, rigid scaffolds in that they are injectable and can be tailored to mimic the mechanical properties of the surrounding tissue. Although both electro spun fibers and hydrogels display favorable characteristics for biomedical applications in vitro, there in vivo benefits are limited due to inherent deficiencies Therefore, to advance the field of biomaterials research, a composite material containing electro spun fibers …

The Effect Of Adding Organic Polymers To Ca-Sr-Zn-Si Glass Polyalkenoate Cement, A. Coughlan, N. M. Cummins, A. W. Wren, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

To conclude, the addition of polymers to GPCs resulted in little change to the Tw and Ts, however the compressive strength was found to decrease slightly. ASAP tests revealed that the cements may undergo some structural changes as a result of these additions. In the future perhaps the addition of organic polymers suspended in the liquid phase as part of the cement may yield improved results in this type of study. © 2011 IEEE.

Fabrication And Analysis Of Variable Density Poly-(L)-Lactic Acid Fiber Scaffolds, N. W. Zaccor, C. J. Rivet, R. J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Poly-L-lactic acid (PLLA) is an extensively studied synthetic polymer that has demonstrated utility as a scaffolding material. A common technique for the fabrication of PLLA scaffolds is electrospinning. The purpose of the present material study was to assess whether an electrospinning process could produce consistent and uniform PLLA scaffold densities. An 8% PLLA solution was made using a 1:1 chloroform: dichloromethane solution and was then run through an electrospinning apparatus. Samples were spun onto 4% PLLA films for 2- or 20-min. Scanning electron microscopy (SEM) was used for imaging the scaffolds. A nine-measurement data set was used for the assessment …

Aligned, Electrospun Topography For Use With External Stimulus Systems, S. G. Quallich, C. J. Rivet, R. J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Variations in fiber density, diameter, and orientation can be used to direct cell migration and guide neurite growth. The characterization of electro spun fibers is essential prior to conducting further research that utilizes electro spun scaffolds to control the magnitude and direction of cell migration and neurite growth. The goal of this study is to create highly aligned, electro spun fibers on poly-L-lactic acid (PLLA) films in parallel and perpendicular orientations to the long axis of rectangular cover slips. Fibers were electro spun into scaffolds and scanning electron microscopy (SEM) was used to characterize fiber density and orientation. The construction …

Using Cerebrospinal Fluid For In Situ Fabrication Of Injectable Alginate Hydrogels For Spinal Cord Repair, C. A. Mckay, R. J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Severe mechanical trauma of the spinal cord induces a secondary injury response that contributes to post injury cell death and the formation of barriers inhibitory to neuronal regeneration. It is believed that engineered scaffolds produce favorable results when they mimic the properties of the t issue that they are aiming to replicate. Alginate hydrogels have been shown to be beneficial in a number of biomaterial applications and this study shows that alginate hydrogels formed in the presence of an artificial cerebrospinal fluid are able to form hydrogels with mechanical properties similar to those exhibited by neural tissue in the CNS. …

Decreasing The Gelation Time Of Fibrin Hydrogels, C. D. Johnson, J. Zudiema, R. J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Spinal cord injury (SCI) is a debilitating problem that often results in paraplegia or quadriplegia. Fibrin hydrogels can be injected into the injured cavity and fill the irregular space. Current techniques require 60 minutes to form a hydrogel. The purpose of this study was to design a fibrin biomaterial that would solidify at a faster rate. By augmenting the existing fabrication procedure, a novel biomaterial was created that formed in 5-7 minutes but lost much of its mechanical stability. Further studies will be performed to improve the mechanical properties while maintaining the faster rate of formation observed here. © 2011 …

A Comparison Of Two Headless Compression Screws For Operative Treatment Of Scaphoid Fractures, Ruby Grewal, Joseph Assini, David Sauder, Louis Ferreira, Jim Johnson, Kenneth Faber

Surgery Publications

PURPOSE: The purpose of this study was to compare the interfragmentary compression force across a simulated scaphoid fracture by two commonly used compression screw systems; the Acutrak 2 Standard and the 3.0 mm Synthes headless compression screw.

METHODS: Sixteen (8 pairs; 6 female, 2 male) cadaver scaphoids were randomly assigned to receive either the Acutrak 2 or Synthes screw with the contralateral scaphoid designated to receive the opposite. Guide wires were inserted under fluoroscopic control. Following transverse osteotomy, the distal and proximal fragments were placed on either side of a custom load cell, to measure interfragmentary compression. Screws were placed …

Use Of Imaging Biomarkers To Assess Perfusion And Glucose Metabolism In The Skeletal Muscle Of Dystrophic Mice, Nabeel Ahmad, Ian Welch, Robert Grange, Jennifer Hadway, Savita Dhanvantari, David Hill, Ting-Yim Lee, Lisa M Hoffman

Robarts Imaging Publications

BACKGROUND: Duchenne muscular dystrophy (DMD) is a severe neuromuscular disease that affects 1 in 3500 boys. The disease is characterized by progressive muscle degeneration that results from mutations in or loss of the cytoskeletal protein, dystrophin, from the glycoprotein membrane complex, thus increasing the susceptibility of contractile muscle to injury. To date, disease progression is typically assessed using invasive techniques such as muscle biopsies, and while there are recent reports of the use of magnetic resonance, ultrasound and optical imaging technologies to address the issue of disease progression and monitoring therapeutic intervention in dystrophic mice, our study aims to validate …

Determining A Method For Rendering Low Cost Cdse(Zns) Core(Shell) Quantum Dots Aqueous Soluble Via Amphiphilic Polymer Wrapping, Patrick Mcbride

Materials Engineering

Herein is described the procedure of two amphiphilic polymer wrapping techniques that may be employed for obtaining aqueous soluble quantum dots (QDs) for use in biological fluorescent imaging applications. The advent of QDs has led to new nanoscale fluorescent materials that exhibit unparalleled quantum yields (QYs), high resistance to photobleaching, tunable emissions, and
absorption over a large optical range. However, the QD synthesis employed here at Cal Poly to obtain bright, photostable CdSe(ZnS) core(shell) QDs involves the use of organic solvents and surfactants, leading to hydrophobic QDs. Since all of biology relies on aqueous solubility, this hydrophobicity creates a major …

Effects Of Phosphate-Buffered Saline Concentration And Incubation Time On The Mechanical And Structural Properties Of Electrochemically Aligned Collagen Threads, Jorge Alfredo Uquillas, Vipuil Kishore, Ozan Akkus

Biomedical Engineering and Sciences Faculty Publications

A key step during the synthesis of collagen constructs is the incubation of monomeric collagen in phosphate buffer saline (PBS) to promote fibrillogenesis in the collagen network. Optimal PBS-treatment conditions for monomeric collagen solutions to induce gelation are well established in the literature. Recently, a report in the literature (Cheng et al 2008 Biomaterials 29 3278-88) showed a novel method to fabricate highly oriented electrochemically aligned collagen (ELAC) threads which have orders of magnitude greater packing density than collagen gels. The optimal PBS-treatment conditions for induction of D-banding pattern in such a dense and anisotropic collagen network are unknown. This …

Heart-Rate Monitoring Control System Using Photoplethysmography (Ppg), Wesley Nguyen, Ryan Horjus

Electrical Engineering

No abstract provided.

Detection Of Breathing And Infant Sleep Apnea, Brian Berg

Computer Engineering

Sleep apnea is a condition where people pause while breathing in their sleep; this can be of great concern for infants and premature babies. Current monitoring systems either require physical attachment to a user or may be unreliable. This project is meant to develop a device that can accurately detect breathing through sound and issue appropriate warnings upon its cessation. The device produced is meant to be a standalone device and thus was developed as an embedded systems project on a Xilinx Spartan 6 FPGA.

Studying Milk Coagulation Kinetics With Laser Scanning Confocal Microscopy, Image Processing, And Computational Modeling, Richard Joseph Hennessy

Master's Theses

The kinetics of milk coagulation are complex and still not well understood. A deeper understanding of coagulation and the impact of the relevant factors would aid in both cheese manufacturing and also in determining the nutritional benefits of dairy products. A method using confocal microscopy was developed to follow the movement of milk fat globules and the formation of a milk protein network during the enzyme-induced coagulation of milk. Image processing methods were then used to quantify the rate of coagulation. It was found that the texture of the protein network is an indicator of the current status of the …

Implementation And Assessment Of Hyperglycemic Conditions For The Creation Of A Diabetic Blood Vessel Mimic, Vikramaditya Mediratta

Master's Theses

Introduction: Diabetes Mellitus is a metabolic disorder that affects a person’s ability to either produce insulin (Type I diabetes mellitus) or properly use insulin (Type II diabetes mellitus) in order to maintain adequate blood glucose levels. The most severe diabetic complications arise due to hyperglycemia – a state of extremely high blood glucose levels – such as, coronary artery disease (CAD), in which coronary stent therapy is a popular method of treatment. However, research has shown a high rate of in-stent restenosis in diabetic patients with CAD, most likely due to activation of cellular adhesion molecules on endothelial cells exposed …

A Novel Exercise Device For Users In Wheelchairs: A Study Of Abdominal Muscle Activation, Rebecca Jo Campbell

Master's Theses

This study evaluates the use of a wheelchair balance board. The balance board was created as a sensory stimulation tool for users with various disabilities. It was originally designed to create vestibular stimulation for the person after they were loaded on.  This study was used as a way to test if the balance board could be used for other things such as physical therapy and exercise.  Ten able-bodied individuals were used to show the functionality of the device.  They were asked to perform six different abdominal exercises while the muscle activity of their rectus abdominis and external obliques was measured …

Measuring The Nanoindentation Properties Of Alendronate-Time Treated Canine Cortical, Folorunso Ashaolu

Master's Theses

This study examines the nanoindentation (energy inclusive) properties of 0.2 mg/kg alendronate treated ribs at one and three years against a vehicle treated control in a fresh-frozen, non-cold-mounted, condition.  This was to verify if the tissue-level properties for 0.2 ALN treated beagles would increase because of an increased level of mineralization despite a microdamage increase.

A total of twelve (12) skeletally mature (1–2 years old) female beagle dogs were treated daily for three years and one year with oral doses of vehicle (VEH, 1 mL/kg saline) or alendronate (ALN, 0.2 Merck, Rahway, NJ). The 0.2 mg dose corresponds, on a …

Ischemia Impairs Vasodilation In Skeletal Muscle Resistance Artery, Kyle Remington Struthers

Master's Theses

Functional vasodilation in arterioles is impaired with chronic ischemia. We sought to examine the impact of chronic ischemia and age on skeletal muscle resistance artery function. To examine the impact of chronic ischemia, the femoral artery was resected from young (2-3mo) and adult (6-7mo) mice and the profunda femoris artery diameter was measured at rest and following gracilis muscle contraction 14 days later using intravital microscopy. Functional vasodilation was significantly impaired in ischemic mice (14.4±4.6% vs. 137.8±14.3%, p<0.0001 n=8) and non-ischemic adult mice (103.0±9.4% vs. 137.8±14.3%, p=0.05 n=10). In order to analyze the cellular mechanisms of the impairment, a protocol was developed to apply pharmacological agents to the experimental preparation while maintaining tissue homeostasis. Endothelial and smooth muscle dependent vasodilation were impaired with ischemia, 39.6 ± 13.6% vs. 80.5 ± 11.4% and 43.0 ± 11.7% vs. 85.1 ± 10.5%, respectively. From this data, it can be supported that smooth muscle dysfunction is the reason for the observed impairment in arterial vasodilation.

A Pmma Conductivity Pretreatment Microfluidics Device For The Optimization Of Electrokinetic Manipulations, Cameron Paul Purcell

Master's Theses

This project encompasses the design and development of a pretreatment microfluidic device for samples of physiological conductivity, namely a saline solution. The conductivity was reduced through the combination of dilution and ion removal using electric fields to enable downstream electro kinetic manipulations. The two major parts of this project include (1) designing a pretreatment protocol to reduce the conductivity of the sample solution to an acceptable level and (2) designing /fabricating a microchip that will effectively allow aim (1) to be performed on chip.

This project is one of the first to observe the effects of an electric field, used …