Biomedical Devices and Instrumentation Commons^™

Characterisation Of Ga2o3-Na2o-Cao-Zno- Sio2 Bioactive Glasses, A. W. Wren, T. Keenan, A. Coughlan, F. R. Laffir, D. Boyd, Mark R. Towler, M. M. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

The structural role of Gallium (Ga) is investigated when substituted for Zinc (Zn) in a 0.42SiO₂-0.40-xZnO-0.10Na₂O-0.08CaO glass series, (where x = 0.08). Each starting material was amorphous, and the network connectivity (NC) was calculated assuming Ga acts as both a network modifier (1.23), and also as a network former. Assuming a network forming role for Ga the NC increased with increasing Ga concentration throughout the glass series (Control 1.23, TGa-1 2.32 and TGa-2 3.00). X-ray photoelectron spectroscopy confirmed both composition and correlated NC predictions. Raman spectroscopy was employed to investigate Q-structure and found that a shift …

The Effect Of A Triphasic Pulse On Scs To Icd Crosstalk, Ryan James Wensley

Master's Theses

It is a known problem that a Spinal Cord Stimulator (SCS) can interact with an Implantable Cardioverter Defibrillator (ICD) when both devices are implanted in the same patient. Interactions between the SCS and ICD can cause inappropriate therapy which can be harmful to the patient. While ICD devices have a distinct narrowband sensing bandwidth, the pulse configurations that current SCS devices deliver were not designed with this frequency region in mind. In this thesis, I recommend a new pulse configuration for SCS devices that will minimize the interaction between the two devices. I produce a theoretical equation for each pulse …

Analysis Of Acetabular Cup Orientation Effects On Stress Shielding In Total Hip Replacements Using Finite Element Methods, Brogan Mcguire, Jennifer Gemkow, Brad Gausewitz, Alex Georges

Biomedical Engineering

Improper positioning of the acetabular cup has been shown to contribute to issues such as high wear rates and dislocations in total hip replacements. The differences in contact mechanics due to varying orientation of the acetabular cup may also significantly affect strain distribution in the femur. This study examined these effects of acetabular orientation changes and their contribution to stress shielding using finite element analysis. A solid model of a cementless total hip implant was obtained using 3D point scanning and implanted virtually into a femur solid model. The implanted femur model was imported into ABAQUS and loaded with a …

A Mouse Model Of Aortic Endothelial Denudation And Neointimal Formation, Ashkon C. Nehzati

Biomedical Engineering

More than 385,000 people die from coronary heart disease (CHD) annually and treatment costs $108.9 billion each year including the cost of health care services, medications, and lost productivity. CHD decreases heart function by limiting oxygen and nutrient transport carried through the coronary arteries. A complete block to the coronary arteries causes a myocardial infarction in response to an elimination of blood supply to cardiomyocytes. Partial occlusion results in insufficient blood supply to cardiomyocytes, producing myocardial ischemia and angina, which are usually treated with intravascular stents deployed percutaneously, before myocardial infarction occurs. Stents are the most common ways to expand …

Design And Development Of A Stair Ascension Assistive Device For Transfemoral Amputees, Casey Michael Barbarino

Master's Theses

Transfemoral amputees around the world experience increased difficulty in climbing stairs due to lack of muscle, balance, and other factors. The loss of a lower limb greatly diminishes the amount of natural force generation provided that is necessary to propel oneself up stairs. This study investigated possible solutions to the problem of stair ascension for transfemoral amputees by the means of designing and developing an externally attachable device to a prosthesis. The number of amputations from military service has greatly increased since 2008, which shows there is a clear need for assistive devices (Wenke, Krueger, & Ficke, 2012). With the …

Biomedical Photoacoustic Imaging Using Gas-Coupled Laser Acoustic Detection, Jami L. Johnson

Student Research Initiative

Several detection methods have been explored for photoacoustic and ultrasound imaging of biological tissues. Piezoelectric transducers are commonly used, which require contact with the sample and have limiting bandwidth characteristics. Interferometry detection exhibits improved bandwidth characteristics and resolution, yet generally require complicated optics and the incorporation of a contacting reflective medium. Here, we report the use of a noncontact photoacoustic and laser-ultrasound imaging system that does not require the use of a reflective layer. A simple, robust technique known as gas-coupled laser acoustic detection is used, which has previously been applied to composite material evaluation. This technique has the potential …

Device Engineering For Infectious Disease Diagnosis Using Isothermal Dna Amplification And Lateral Flow Detection, Kristina Roskos

KGI Theses and Dissertations

Technologies that enable infectious diseases diagnosis in low-resource settings could greatly facilitate effective treatment and containment of such diseases. Nucleic acid amplification testing can be used to identify pathogens, but typically requires highly-trained personnel and large, expensive lab equipment, neither of which is available in low-resource settings. Our overall goal is to develop a portable diagnostic system that utilizes a low-cost, disposable, mesofluidic cartridge and a handheld electronics unit to perform fully-integrated nucleic acid testing at the point of care in low-resource settings. As a first step toward this goal, we developed a subunit to execute isothermal nucleic acid amplification …

Aluminium-Free Glass Polyalkenoate Cements: Ion Release And In Vitro Antibacterial Efficacy, A. W. Wren, J. P. Hansen, S. Hayakawa, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) have exhibited potential as bone cements. This study investigates the effect of substituting TiO₂ for SiO₂ in the glass phase and the subsequent effect on cement rheology, mechanical properties, ion release and antibacterial properties. Glass characterization revealed a reduction in glass transition temperature (T_g) from 685 to 669 C with the addition of 6 mol % TiO₂ (AT-2). Magic angle spinning nuclear magnetic resonance (MAS-NMR) revealed a shift from -81 ppm to -76pmm when comparing a Control glass to AT-2, indicating de-polymerization of the Si network. The incorporation of TiO_{2 …}

Closed Loop Control Of A Cylindrical Tube Type Ionic Polymer Metal Composite (Ipmc), Benjamin Mead

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this research is to provide a framework for the integration of tube type, cylindrical Ionic Polymer Metal-Composite (IPMC) into conventional devices. IPMCs are one of the most widely used types of electro-active polymer actuator, due to their low electric driving potential and large deformation range. For this research a tube type IPMC was investigated. This IPMC has a circular cross section with four separate electrodes on its surface and a hole through the middle. The four electrodes allow for biaxial bending and accurate control of the tip location. One of the main advantages of using this type …

Modeling The Zimmer Fitmore And Ml Taper Implantation, Tyler Kazuo Franklin

Master's Theses

With more young adults requiring total hip

arthroplasties the need for bone saving implants becomes

more important. The Zimmer Fitmore is a new bone saving

implant that utilizes an implantation technique that

reduces the damage to the muscle tissue allowing for

patients to have a short recovery time as well as a new

design that allows it to rest on the medial cortex. There

has been anecdotal evidence that this device leads to early

revision within six months of implantation due to failures

occurring in the medial cortex. The main goal of this

study was to computationally model the Zimmer …

Design And Implementation Of Wireless Point-Of-Care Health Monitoring Systems: Diagnosis For Sleep Disorders And Cardiovascular Diseases, Se Chang Oh

Graduate Theses and Dissertations

Chronic sleep disorders are present in 40 million people in the United States. More than 25 million people remain undiagnosed and untreated, which accounts for over $22 billion in unnecessary healthcare costs. In addition, another major chronic disease is the heart diseases which cause 23.8% of the deaths in the United States. Thus, there is a need for a low cost, reliable, and ubiquitous patient monitoring system. A remote point-of-care system can satisfy this need by providing real time monitoring of the patient's health condition at remote places. However, the currently available POC systems have some drawbacks; the fixed number …

Design And Testing Of Novel Mouthguard With Intermediate Nitinol And Foam Layers, Adam Kessler

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is the aim of this study to investigate a novel mouthguard design that incorporates the use of a nickel-titanium (Nitinol) layer and thin foam layer in addition to EVA layers. It is thought that the Nitinol layer can distribute the force of an impact and that the thin foam layer may absorb this distributed force better than a solid EVA mouthguard of the same thickness. Rectangular, flat coupons representative of several mouthguard configurations were constructed for testing using an instrumented drop-weight impact tower. The coupon configurations include a control made of laminated EVA, a group of laminated EVA and …

Novel Approach To Junctional Bleeding: Tourniquet Device Proposal For Battlefield Hemorrhage Control, Kyle W. Cabaniss

Master's Theses

This study investigated possible solutions to the current wartime problem of junctional hemorrhaging, or massive traumatic hemorrhaging in non-tourinquetable areas such as the neck, groin, or armpit. Junctional hemorrhaging has been identified as a major contributor to potentially survivable deaths seen on the battlefield today and therefore is a priority for the U.S. armed and coalition forces (Kragh et al., 2011a; Bozeman, 2011). Common tourniquets today are standard issue and carried by soldiers in the military, but are limited to distal extremity trauma. As the battlefield has changes however, trauma has transformed from commonly seen gunshot wounds to more extreme …

A Microfluidic Pretreatment Isoelectric Focusing Dc-Field Assisted H-Filter For The Separation Of Charged Particles, Cameron Sean Carroll

Biomedical Engineering

Microfluidic devices are small portable diagnostic chips that allow for analysis of a biologic sample at relatively low cost. This makes them ideal for settings where a hospital is unavailable. The microfluidic pretreatment isoelectric focusing DC-field assisted H-filter is a device that allows for the separation of differently charged particles in a biologic sample. It does this by employing the concepts of diffusion, electrophoresis, and isoelectric focusing. This is perfect for isolation of a desired analyte or separation of waste from a sample in order to achieve better diagnostic results. The device was first modeled mathematically and visually using Comsol. …

Comparison Of A Sio2-Cao-Zno-Sro Glass Polyalkenoate Cement To Commercial Dental Materials: Glass Structure And Physical Properties, A. W. Wren, A. Coughlan, F. R. Laffir, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) have previously been considered for orthopedic applications. A Zn-GPC (BT 101) was compared to commercial GPCs (Fuji IX and Ketac Molar) which have a setting chemistry analogous to BT 101. Handling properties (working, T_w and setting, T_s times) for BT 101 were shorter than the commercial GPCs. BT 101 also had a higher setting exotherm (S_x - 34 °C) than the commercial GPCs (29 °C). The maximum strengths for BT 101, Fuji IX, and Ketac Molar were 75, 238, and 216 MPa (compressive, σ_c), and 34, 54, and 62 MPa (biaxial …

Easily Implantable And Stable Nail-Fastener For Skeletal Fixation And Method, Patrick Atkinson, David Lecronier

Mechanical Engineering Patents

An intramedullary nail (20) defining a bore (34) is inserted into a medullary canal (26) of a bone (24). A threaded fastener (22) has a compression portion (48) presenting a compression portion diameter (D) and a threaded portion (50) present ing a threaded portion diameter (D). The fastener (22) extends through a near cortex hole (40) and/or a far cortex hole (42), and the threaded portion (22) threadedly engages the bore (34). A compression transmission device (54) is disposed between a head (44) of the fastener (22) and the intramedullary nail (20) for transmitting the compressional load of the threaded …

Automated Point-Of-Care Image Processing Methodology For The Diagnosis Of Malaria, Michael B. Jorgensen

Master's Theses

Malaria has profoundly influenced human history for over four thousand years and despite numerous attempts at eradication, the prevention, diagnosis, and treatment of malaria have been largely ineffective. More than five hundred million people are affected by malaria every year resulting in over one million deaths. Drug resistance development by the parasite has diminished the effectiveness of numerous treatment options due, in part, to overtreatment of negative patients based on insufficient clinical algorithms and diagnostic methods. The goal of this research was to develop an image analysis algorithm to diagnose malaria with a high degree of sensitivity and specificity in …

Modeling Hrtf For Sound Localization In Normal Listeners And Bilateral Cochlear Implant Users, Douglas A. Miller

Electronic Theses and Dissertations

Mathematical models can be very useful for understanding complicated systems and for testing algorithms through simulation that would be difficult or expensive to implement. This dissertation presents a model that attempts to simulate the sound localization performance of persons using bilateral cochlear implants. The expectation is that this model could prove to be a useful tool in developing new signal processing algorithms for neural encoding strategies.

The head related transfer function (HRTF) is a critical component of this model, and in the ideal case, provides the base characteristics of head shadow, torso and pinna effects. This defines the temporal, intensity …

Diagnosis Of Systemic Inflammation Using Transendothelial Electrical Resistance And Low-Temperature Co-Fired Ceramic Materials, William L. Mercke

Theses and Dissertations--Chemical and Materials Engineering

Systemic inflammation involves a complex array of cytokines that can result in organ dysfunction. Mortality remains high despite the vast amount of research conducted to find an effective biomarker. The cause of systemic inflammation can be broad and non-specific; therefore, this research investigates using transendothelial electrical resistance (TEER) measurements to better define systemic inflammatory response syndrome (SIRS)/sepsis within a patient. Results show a difference in TEER measurements between healthy individuals and SIRS-rated patients. This research also displays correlations between TEER measurements and biomarkers currently studied with systemic inflammation (tumor necrosis factor-α, C- reactive protein, procalcitonin). Furthermore, this research also presents …

Independent Component Analysis Enhancements For Source Separation In Immersive Audio Environments, Yue Zhao

Theses and Dissertations--Electrical and Computer Engineering

In immersive audio environments with distributed microphones, Independent Component Analysis (ICA) can be applied to uncover signals from a mixture of other signals and noise, such as in a cocktail party recording. ICA algorithms have been developed for instantaneous source mixtures and convolutional source mixtures. While ICA for instantaneous mixtures works when no delays exist between the signals in each mixture, distributed microphone recordings typically result various delays of the signals over the recorded channels. The convolutive ICA algorithm should account for delays; however, it requires many parameters to be set and often has stability issues. This thesis introduces the …

Biomechanical Comparison Of Lower Limb Unloading Between Common Modalities Of Ankle Foot Orthoses, Andrea Blake Wanamaker

Electronic Theses and Dissertations

Tibial stress fractures and other lower extremity injuries can be treated using an ankle foot orthosis (AFO). AFOs are popular because they allow the patient to ambulate somewhat naturally while reducing weight bearing on the injured limb. Despite their popularity, it is currently unclear how well AFOs reduce lower extremity weight bearing.

The first objective of this investigation was to examine the ability of three commonly used ankle foot orthoses to reduce weight bearing within the lower limb by comparing the ground reaction force measured from a force platform to the force measured from an insole pressure measurement device inside …

Computational Representation Of The Patellofemoral Joint, Abraham Wright

Electronic Theses and Dissertations

Many people suffer from knee pain due to abnormal function of the patellofemoral joint and are not able to enjoy normal activities of daily living. Surgical treatments are available and new methods are being developed by the medical industry. However, computational tools to efficiently evaluate the effects of the intervention on patellofemoral function are lacking.

Therefore, a validated and efficient computational model of the patellofemoral joint was developed. The subject specific finite element model was validated against the patellar kinematics recorded during cadaveric patellofemoral laxity experiments of the natural knee. The development involved a sequential process in which the soft-tissue …