Biomedical Devices and Instrumentation Commons^™

Antimicrobial Efficacy And Safety Of A Novel Gas Plasma-Activated Catheter Lock Solution, Sudhir Bhatt, Poonam Mehta, Chen Chen, Dayle A. Daines, Leonard A. Mermel, Hai-Lan Chen, Michael G. Kong

Bioelectrics Publications

Antimicrobial lock solutions are important for prevention of microbial colonization and infection of long-term central venous catheters. We investigated the efficacy and safety of a novel antibiotic-free lock solution formed from gas plasma-activated disinfectant (PAD). Using a luminal biofilm model, viable cells of methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Candida albicans in mature biofilms were reduced by 6 to 8 orders of magnitude with a PAD lock for 60 min. Subsequent 24-h incubation of PAD-treated samples resulted in no detectable regrowth of viable bacteria or fungi. As a comparison, the use of a minocycline-EDTA-ethanol lock solution for 60 …

Determining The Effect Of Locally Delivered Bioactive Modulators On Macrophage Activation At The Implantation Site Of Different Biomaterials In Rats, Kamel Alkhatib

Graduate Theses and Dissertations

Altering the foreign body reaction by targeting macrophages has been of interest in the biomaterials field to improve the integration of longevity of implanted biomedical devices. The objective of this dissertation was to study the effect of locally delivered bioactive modulators on macrophage activation at the implantation site of different biomaterials in rats. Iloprost, a prostacyclin analog, was tested for its ability to direct macrophages to their pro-wound healing phenotype after the implantation of microdialysis probe in the subcutaneous space of male Sprague Dawley rats. This study showed that iloprost can shift macrophage activation states in vivo to the pro-wound …

Developing Droplet Based 3d Cell Culture Methods To Enable Investigations Of The Chemical Tumor Microenvironment, Jacqueline Alexandria De Lora

Biomedical Sciences ETDs

Adaptation of cancer cells to changes in the biochemical microenvironment in an expanding tumor mass is a crucial aspect of malignant progression, tumor metabolism, and drug efficacy. In vitro, it is challenging to mimic the evolution of biochemical gradients and the cellular heterogeneity that characterizes cancer tissues found in vivo. It is well accepted that more realistic and controllable in vitro 3D model systems are required to improve the overall cancer research paradigm and thus improve on the translation of results, but multidisciplinary approaches are needed for these advances. This work develops such approaches and demonstrates that new droplet-based cell-encapsulation …

Wearable Assistive Technologies For Autism: Opportunities And Challenges, Emma Mansouri Benssassi, Juan-Carlos Gomez, Louanne E. Boyd, Gillian R. Hayes, Juan Ye

Engineering Faculty Articles and Research

Autism is a lifelong developmental condition that affects how people perceive the world and interact with others. Challenges with typical social engagement, common in the autism experience, can have a significant negative impact on the quality of life of individuals and families living with autism. Recent advances in sensing, intelligent, and interactive technologies can enable new forms of assistive and augmentative technologies to support social interactions. However, researchers have not yet demonstrated effectiveness of these technologies in long-term real-world use. This article presents an overview of the social and sensory challenges of autism, which offer great opportunities and challenges for …

Chemotherapeutic Drug Cytotoxicity Measurement With A 3d Biomimetic Microfluidic Device And Computational Fluid Dynamics Model, Maryam Moarefian, Caroline Jones, Luke Achenie, Danesh Tafti

Biology and Medicine Through Mathematics Conference

No abstract provided.

Development Of Low Frequency Electron Paramagnetic Resonance Methods And Instrumentation For Biological Applications, Laura A. Buchanan

Electronic Theses and Dissertations

EPR is a powerful biophysical tool that can be used to measure tumor physiology. With the addition of magnetic field gradients, the spectral properties of paramagnetic species can be mapped. To facilitate EPR imaging, methods and instrumentation at frequencies between 250 MHz and 1 GHz were developed.

At low spin concentrations, the rapid scan background signal is often many times larger than the EPR signal of interest. To help remove the background contribution, a data acquisition procedure that takes advantage of a cross-loop resonator and bipolar power supplies was developed at 250 MHz. In this procedure, two scans are collected. …

Stabilization Of Hypoxia Inducible Factor By Cobalt Chloride Can Alter Renal Transepithelial, Subhra Sankar Nag

ETD Archive

Kidney cyst expansion, stagnant fluid accumulation, and insufficient vascular supply can result in localized chronic ischemia-hypoxia in kidney cysts, as well as in normal renal epithelia adjacent to a cyst. We hypothesize that in normal epithelia near a cyst, the stabilization of Hypoxia Inducible Factor 1a (HIF1a), a major regulator of cellular response to hypoxia, can cause altered paracellular and transcellular transport, transforming a normal absorptive phenotype to a secretory and paracellularly leaky phenotype, leading to cyst expansion. Using 100 µmol/L cobalt chloride (CoCl2), HIF1a was stabilized in cellular nucleus of a mouse cortical collecting duct cell line (mCCD 1296 …

Collective Chemotaxis Of Retinal Neural Cells From Drosophila Melanogaster In Controlled Microenvironments, Stephanie Zhang

Dissertations and Theses

More than 172 million people are influenced by a retinal disorder that stems from either age-related or developmental causes. Of those, 1.5 million people endure a developmental retinal disorder. In the developing retina, neural cells undergo a series of highly complicated differentiation and migration process. A main cause of these diseases is abnormal collective migration of neural progenitors hindering the retinogenesis process. However, our grasp of collective migration and signaling molecules, critical to the developing retina, is incompletely understood. Understanding the molecular mechanisms, such as the fibroblast growth factor pathway, that regulate glial and neuronal migration provides decisive insights in …

Co-Modulation Masking Release Begins In The Auditory Periphery, Kareem R. Hussein, Agudemu Borjigan, Mark Sayles

The Summer Undergraduate Research Fellowship (SURF) Symposium

Understanding speech in noisy environments can be difficult, especially for people with hearing loss. The background noise can cover up the sounds of interest. Normally, the auditory system works to alleviate this problem by tagging and then cancelling the noise. Our experiments are aimed at understanding the mechanism of this noise cancellation process. We hypothesize that non-linear signal processing in the mammalian cochlea (the most peripheral part of the auditory system) is the basis of noise cancellation. To test this hypothesis, we measured the responses of auditory-nerve fibers (ANFs) to sounds embedded in background noise with different statistical properties. ANFs …

Optimization Of Prosthetic Hands: Utilizing Modularity To Improve Grip Force, Grasp, And Versatility, Jordan William Harris

UNLV Theses, Dissertations, Professional Papers, and Capstones

It has been demonstrated that although many varieties of upper limb prosthetics exist, commercially available prosthetics are outdated and unsatisfactory. Ineffectiveness and limitations have led to some prosthesis wearers having to own multiple devices, whereas others have given up on them entirely. Even though ample research has been conducted to design and test new hand designs, the industry appears to rest in an overall stagnated state.

It was proposed here, that one problem with prosthetic research is an excess of variables involved in testing, and therefore the improper application of the scientific method. It seems that each time a research …

A Deterministic Model Of The Effect Of Electric Field On Chemotherapeutics Delivery Into A Tumor, Maryam Moarefian, Luke Achenie

Biology and Medicine Through Mathematics Conference

No abstract provided.

Detection Of Leukocytes Stained With Acridine Orange Using Unique Spectral Features Acquired From An Image-Based Spectrometer, Courtney J. Hunter

Biomedical Engineering Undergraduate Honors Theses

A leukocyte differential count can be used to diagnosis a myriad blood disorders, such as infections, allergies, and efficacy of disease treatments. In recent years, attention has been focused on developing point-of-care (POC) systems to provide this test in global health settings. Acridine orange (AO) is an amphipathic, vital dye that intercalates leukocyte nucleic acids and acidic vesicles. It has been utilized by POC systems to identify the three main leukocyte subtypes: granulocytes, monocytes, and lymphocytes. Subtypes of leukocytes can be characterized using a fluorescence microscope, where the AO has a 450 nm excitation wavelength and has two peak emission …

Biophysical Tools To Study Cellular Mechanotransduction, Ismeel Muhamed, Farhan Chowdhury, Venkat Maruthamuthu

Mechanical & Aerospace Engineering Faculty Publications

The cell membrane is the interface that volumetrically isolates cellular components from the cell's environment. Proteins embedded within and on the membrane have varied biological functions: reception of external biochemical signals, as membrane channels, amplification and regulation of chemical signals through secondary messenger molecules, controlled exocytosis, endocytosis, phagocytosis, organized recruitment and sequestration of cytosolic complex proteins, cell division processes, organization of the cytoskeleton and more. The membrane's bioelectrical role is enabled by the physiologically controlled release and accumulation of electrochemical potential modulating molecules across the membrane through specialized ion channels (e.g., Na^⁺, Ca²⁺, K^⁺ channels). …

A Portable And Automatic Biosensing Instrument For Detection Of Foodborne Pathogenic Bacteria In Food Samples, Zhuo Zhao

Graduate Theses and Dissertations

Foodborne diseases are a growing public health problem. In recent years, many rapid detection methods have been reported, but most of them are still in lab research and not practical for use in the field. In this study, a portable and automatic biosensing instrument was designed and constructed for separation and detection of target pathogens in food samples using nanobead-based magnetic separation and quantum dots (QDs)-labeled fluorescence measurement. The instrument consisted of a laptop with LabVIEW software, a data acquisition card (DAQ), a fluorescent detector, micro-pumps, stepper motors, and 3D printed tube holders. First, a sample in a syringe was …

Mechanical Reliability Of Implantable Polyimide-Based Magnetic Microactuators For Biofouling Removal, Christian G. Figueroa-Espada, Qi Yang, Hyowon Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hydrocephalus is a neurological disorder that typically requires a long-term implantation of a shunt system to manage its symptoms. These shunt systems are notorious for their extremely high failure rate. More than 40% of all implanted shunt systems fail within the first year of implantation. On average, 85% of all hydrocephalus patients with shunt systems undergo at least two shunt-revision surgeries within 10 years of implantation. A large portion of this high failure rate can be attributed to biofouling-related obstructions and infections. Previously, we developed flexible polyimide-based magnetic microactuators to remove obstructions formed on hydrocephalus shunts. To test the long-term …

Prosthetic Socket Cooling System, Benjamin K. Kraw, Kathy Ha, Derek Piastrelli, Cuong Lai

Mechanical Engineering

A team of four senior-level undergraduate students in the Interdisciplinary Senior Project Design course in the Engineering Department of California Polytechnic State University: San Luis Obispo have worked to develop a prosthetic socket cooling system, namely for veteran Taylor Morris and exclusively for a transfemoral prosthetic socket, under the Quality of Life+ Laboratory. This cooling system will utilize the thermoelectric effect known as the Peltier effect to transmit heat generated from the residual limb to the surrounding environment by means of forced convection over small aluminum heat sinks. Two measurement devices have also been developed to, one, measure the heat …

The Effect Of Posterior Foot Positions On Electromyography, Joint Kinetics And Energetics During A Sit-To-Stand In Young And Older Adults, Eric A. Pitman

Human Movement Studies & Special Education Theses & Dissertations

The sit-to-stand (STS) movement, defined as standing up from a chair to an upright posture, is a common task performed daily. The inability to accomplish this task may lead to dependence, institutionalization and even death in older adults. A common strategy change for the STS is positioning the feet posteriorly by increasing flexion at the knee joint. This reduces the displacement of the center of mass to the base of support while increasing the joint moment of force at the knee while decreasing it at the hip. The aims of this study were to: 1) examine the joint kinetics, joint …

3d Printing In Healthcare, Caleb Branch

The Review: A Journal of Undergraduate Student Research

Technology is everywhere. Technology surrounds every aspect of 21^st century life. It is in the cell phones we use, the cars we drive, and even the food we eat. A large portion of modern technology used is taken for granted and overlooked. Despite this, some technology fields continue to grow. Biomedical engineering, specifically 3D printing’s applications to healthcare, has been often overlooked until. Regardless of its status in the mainstream, 3D printing is prosperous in healthcare and its future looks bright. This piece analyzes 3D printing in healthcare. It hones in on the finer details of each specific topic, …

A Portable Impedance Biosensing System Based On A Laptop With Labview For Rapid Detection Of Avian Influenza Virus, Yixiang Wang

Graduate Theses and Dissertations

Avian Influenza Virus (AIV) H5N1 is a highly pathogenic virus found not only in birds but also in human. Rapid and sensitive detection method is needed to help prevent the spread of AIV H5N1. In this study, a portable impedance biosensing system based on a laptop with LabVIEW software was developed for detection of AIV H5N1. First, a virtual instrument was programmed with LabVIEW software to form a platform for impedance measurement, data processing and control. The audio card of a laptop was used as a function generator while a data acquisition card was used with the signal channels for …

Induction Of Differentiation Of Dental Pulp-Derived Mesenchymal Stem Cells (Dpsc), Aubrey Young

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mesenchymal stem cells are derived from a variety of human tissues and are being bioengineered and studied for possible uses in the advancement of medicine. Recent efforts are being focused on Dental Pulp Stem Cells (DPSC's) due to the accessibility of this tissue. Many factors influence DPSC quality and quantity, including the specific methods used to isolate, collect, concentrate, and store these isolates once they are removed. Ancillary factors, such as the choice of media, the selection of early versus late passage cells, and cryopreservation techniques may also influence the differentiation potential and proliferative capacity of DPSC isolates.

The objective …

Impedance Biosensors For The Rapid Detection Of Viral And Bacterial Pathogens Using Avian Influenza Virus Subtypes H5n1 And H7n2 And Escherichia Coli O157:H7 As Model Targets, Jacob David Lum

Graduate Theses and Dissertations

This research investigated impedance biosensors for the rapid detection of viral and bacterial pathogens using avian influenza virus (AIV) subtypes H5N1 and H7N2 and Escherichia coli O157:H7 as the model targets, which were chosen due to their impact on the agricultural and food industries. For the detection of AIV H7N2, a single stranded DNA aptamer was selected using systematic evolution of ligands by exponential enrichment (SELEX). The selected aptamer and a previously selected aptamer against AIV H5N1 were used in a microfluidics chip with an embedded interdigitated array microelectrode to fabricate an impedance biosensor for specific detection of AIV H7N2 …

Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution, Michael D. Furtaw

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Fluorescence spectroscopy is a widely used detection technology in many research and clinical assays. Further improvement to assay sensitivity may enable earlier diagnosis of disease, novel biomarker discovery, and ultimately, improved outcomes of clinical care along with reduction in costs. Near-infrared, surface-enhanced fluorescence (NIR-SEF) is a promising approach to improve assay sensitivity via simultaneous increase in signal with a reduction in background. This dissertation describes research conducted with the overall goal to determine the extent to which fluorescence in solution may be enhanced by altering specific variables involved in the formation of plasmonactive nanostructures of dye-labeled protein and silver nanoparticles …

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 …

A Thousand Tiny Pieces: The Federal Circuit’S Fractured Myriad Ruling, Lessons To Be Learned, And The Way Forward, Jonathan R. K. Stroud

IP Theory

No abstract provided.

Construction And Use Of A Direct Calorimeter To Estimate Energy Expenditure In Hibernators, Mark S. Burger, Frank Van Breukelen

Festival of Communities: UG Symposium (Posters)

Metabolic rates have traditionally been estimated through indirect calorimetry (gas exchange or respirometry) due to its ease and availability. Oxygen consumption neglects the contributions of anaerobic metabolism, while direct calorimetry (heat production) estimates both anaerobic and aerobic metabolism. Walsberg and Hoffman (2005) report anaerobic metabolism may be more important to small rodents than was previously thought. During the non-steady state of mammalian hibernation, we hypothesize that anaerobic processes may play an even greater role in fueling metabolism. To address this question, we constructed a very sensitive calorimeter that utilizes the Seebeck effect from a thermoelectric element (Peltier device). We describe …

Combining Molecular And Imaging Biomarkers To Enhance Maldi Biomarker Analysis, Ayyappa Chowdary Vadlamudi

Electrical & Computer Engineering Theses & Dissertations

This thesis presents a three-step method to predict prostate cancer (PCa) regions on biopsy tissue samples based on high confident, low resolution PCa regions marked by a pathologist. First, a prediction model is designed to predict PCa regions using matrix-assisted laser desorption mass spectrometry (MALDI-MS) tissue imaging data from one prostate tissue slice. Second, a texture analysis technique is applied to a high magnification optical image for the same purpose from an adjacent tissue slice. Finally, those two results are fused to obtain the PCa regions that will assist MALDI imaging biomarker analysis. Experiments show that the texture analysis based …

Prostate Cancer Biomarker Identification: A Comparative Study, Wenjuan Jiang

Computational Modeling & Simulation Engineering Theses & Dissertations

With the current development of proteomics techniques, the discovery of potential molecular biomarkers for early detection of prostate cancer has been greatly improved. In this thesis, we implemented five classifiers including the support vector machine (SVM), Bayesian Classifier, Decision Tree, Random Forest and the Multilayer perceptron (MLP) to test their effectiveness in prostate cancer biomarker identification using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) tissue imaging data. The classifiers were utilized to discriminate cancer mass spectra from normal ones for the data collected at the Eastern Virginia Medical School (EVMS). There are 94 7 spectra from normal tissues and 27 from …

New In Vivo And In Vitro Techniques For Quantification Of Lateral Force Levels That Cause Implants To Fail : A Progress Report On Monkey Research, V. Leroy Leggitt

Loma Linda University Electronic Theses, Dissertations & Projects

Two new techniques for quantification of forces generated by an expansion screw apparatus placed between pairs of cylindrical endosseous titanium implants are described, along with preliminary data gained from their use in Macaca rhesus monkeys. Strain gages were bonded to the expansion apparatus and were calibrated either directly by micro load cell, or indirectly by Instron Machine to reflect the applied force.

Immediate loads of up to 6 kilograms have been applied to the implants with no increase in mobility as verified by a Periotest device. No previous studies on the orthodontic uses of implants have evaluated in vivo forces …

Sharpening And Care Of Mulesing Shears, A L. Jones

Journal of the Department of Agriculture, Western Australia, Series 4

THIS year will probably see more sheep mulesed in Western Australia than ever before.

It is not surprising, therefore, that some improvements have been made to the standard mulesing shears.

New modified shears make mulesing easier —but they must be properly sharpened.