Biomedical Engineering and Bioengineering Commons^™

Neural Network Based Emg Driven Modeling And Control Of Human Walking, Alaa Muheddin Abdulrahman

Theses and Dissertations

Human body modeling (HBM) offers the benefit of replicating human activity into robotics and rehabilitation devices. Gait impairment is a consequence of several diseases like stroke, spinal cord injury, or Parkinson' disease. The modeling techniques developed in robotics have been used to improve gait abnormalities in walking and in building Exoskeletal robots. HBM is resource intensive as it requires setting-up laboratory facilities and using expensive instruments. Further, the data acquired is limited to the number of the participants. In addition, the accuracy of the model is important as it is related to human pathology. In this research, several Matlab based …

Ontogenetic Scaling Patterns And Functional Anatomy Of The Pelvic Limb Musculature In Emus (Dromaius Novaehollandiae), Luis P. Lamas, Russell P. Main, John R. Hutchinson

Department of Basic Medical Sciences Faculty Publications

Emus (Dromaius novaehollandiae) are exclusively terrestrial, bipedal and cursorial ratites with some similar biomechanical characteristics to humans. Their growth rates are impressive, as their body mass increases eighty-fold from hatching to adulthood whilst maintaining the same mode of locomotion throughout life. These ontogenetic characteristics stimulate biomechanical questions about the strategies that allow emus to cope with their rapid growth and locomotion, which can be partly addressed via scaling (allometric) analysis of morphology. In this study we have collected pelvic limb anatomical data (muscle architecture, tendon length, tendon mass and bone lengths) and calculated muscle physiological cross sectional area …

Experimental And Theoretical Studies Of Native And Engineered Vascular Tissue Mechanics, Boran Zhou

Theses and Dissertations

Background: Implantation of vascular grafts provides a means to restore blood flow in compromised regions of the circulatory system, and thus is used to treat a wide range of cardiovascular diseases. Despite significant advancements in autologous grafting strategies as well as the engineering of synthetic alternatives, mechanical, structural, and compositional incongruities between the graft and the host artery remain as contributing factors to graft failure. The typical failure modality manifests as proximal anastomotic intimal hyperplasia, which places restrictions on the host vessel size currently treated with grafting strategies (> 5 mm internal diameter). In order to improve long-term clinical outcomes, …

Real-Time Temperature Imaging Using Ultrasonic Change In Backscattered Energy, Weiyuan Zhao

McKelvey School of Engineering Graduate Student Theses & Dissertations

Thermal therapy from low-temperature cryosurgery to high-temperature ablation of tumors and unwanted electrical pathways has gained increased attention. Temperature imaging (TI) from magnetic resonance studies is the de facto standard for volumetric estimation of temperature. Ultrasound has the advantages of being cheap, portable, non-invasive and non-ionizing. Our group showed in predictions for single scatterers, simulations of scatterer populations and measurements in 1D, 2D and 3D, that CBE changed monotonically with temperature with 1^oC accuracy. An obstacle to clinical application of CBE TI is estimation of temperature in real time, which is limited by time for motion compensation (MC). …

Reduced Astrocyte Viability At Physiological Temperatures From Magnetically Activated Iron Oxide Nanoparticles, Nicholas J. Schaub, Deniz Rende, Yuan Yuan, Ryan J. Gilbert, Diana Andra Borca-Tasciuc

Chemical and Biochemical Engineering Faculty Research & Creative Works

Superparamagnetic iron oxide nanoparticles (SPIONs) can generate heat when subjected to an alternating magnetic field (AMF). In the European Union, SPIONs actuated by AMF are used in hyperthermia treatment of glioblastoma multiforme, an aggressive form of brain cancer. Current data from clinical trials suggest that this therapy improves patient life expectancy, but their effect on healthy brain cells is virtually unknown. Thus, a viability study involving SPIONs subjected to an AMF was carried out on healthy cortical rat astrocytes, the most abundant cell type in the mammalian brain. The cells were cultured with amino silane- or starch-coated SPIONs with or …

Nanopulse Generators: Their Design And Application To Cancer Therapy Studies, Daniel P. Wernig

Senior Honors Theses

Effective nanopulse generators have become critical in recent decades concerning the study of subcellular affects in response to nanosecond pulsed electric fields. It has been observed that nanosecond duration electric pulses can target intracellular organelles, ultimately leading to cell apoptosis, suggesting the possibility of a new, minimally invasive, low risk cancer therapy methodology. The standard topology for developing a medical nanopulser is the Blumlein “transmission line” approach. This approach relies on the nearly infinitesimal, yet finite amount of time required for an electromagnetic field to propagate down a short transmission line. Prior to design, requirements and constraints must be defined …

Processing And Mechanical Testing Of Strontium-Substituted Hydroxyapatite/Glass Composites, Chokchai Yatongchai, Mark R. Towler, Anthony W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

Sr-HA/Glass composites were produced. Phase composition of composites was evaluated. Their physical and mechanical properties were determined. Sintered composites mainly consisted of Sr-HA/β-TCP, or β-TCP/Ca₂ZnSi₂O₇. The composites had porosity up to 4 times those of undoped Sr-HA. Compared to undoped Sr-HA, the Sr-HA/Glass composites had lower biaxial flexural strength and hardness. The Weibull modulus for the composites ranged from 2.77 to 18.74.

Fickian-Based Empirical Approach For Diffusivity Determination In Hollow Alginate-Based Microfibers Using 2d Fluorescence Microscopy And Comparison With Theoretical Predictions, Maryam Mobed-Miremadi, Sabra Djomehri, Mallika Keralapura, Melanie Mcneil

Bioengineering

Hollow alginate microfibers (od = 1.3 mm, id = 0.9 mm, th = 400 µm, L = 3.5 cm) comprised of 2% (w/v) medium molecular weight alginate cross-linked with 0.9 M CaCl₂ were fabricated to model outward diffusion capture by 2D fluorescent microscopy. A two-fold comparison of diffusivity determination based on real-time diffusion of Fluorescein isothiocyanate molecular weight (FITC MW) markers was conducted using a proposed Fickian-based approach in conjunction with a previously established numerical model developed based on spectrophotometric data. Computed empirical/numerical (D_empiricial/D_numerical) diffusivities characterized by small standard deviations for the 4-, 70- and …

Differential Protein Expression Of Caco-2 Cells Treated With Selenium Nanoparticles Compared With Sodium Selenite And Selenomethionine, Linglin Fu, Xuxia Yan, Xinming Ruan, Junda Lin, Yanbo Wang

Biomedical Engineering and Sciences Faculty Publications

The study was designed to determine the differential protein expression of Caco-2 cells treated with different forms of selenium including sodium selenite, selenomethionine (Se-Met), and selenium nanoparticles (nano-Se). Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS) were used to identify the differentially expressed proteins. The results indicated that seven protein spots, ubiquitin-conjugating enzyme E2 (E2), glutathione synthetases (GS), triosephosphate isomerase (TSP), T-complex protein 1 subunit zeta (TCPZ), lamin-B1, heterogeneous nuclear ribonucleoprotein F (hnRNP F), and superoxide dismutase [Cu-Zn] (Cu, Zn-SOD) were significantly different among all the groups. According to the order of control, sodium selenite, Se-Met, and Nano-Se, the …

Targeted Drug Delivery System For Kidney And/Or Liver Failure Patients Using Human Serum Albumin, Sean Bedingfield

Undergraduate Honors Capstone Projects

Compromised liver and/or kidney function reduces the acceptable dosage of a variety of medications that can be administered to patients. These patients still have a need for drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs), antivirals, and antibiotics. The project goal is to provide a drug delivery system to accommodate these reduced dosage limits with added therapeutic benefits to address symptoms of liver or kidney failure. Localized drug delivery allows for a smaller, concentrated dose rather than inundating the patient's system with the drug of interest. Human serum albumin (HSA) is a researched candidate for drug delivery with therapeutic properties. HSA …

Long-Acting Antituberculous Therapeutic Nanoparticles Target Macrophage Endosomes, Benson J. Edagwa, Dongwei Guo, Pavan Puligujja, Han Chen, Joellyn Mcmillan, Xinming Liu, Howard Gendelman, Prabagaran Narayanasamy

Nebraska Center for Biotechnology: Faculty and Staff Publications

Eradication of Mycobacterium tuberculosis (MTB) infection requires daily administration of combinations of rifampin (RIF), isoniazid [isonicotinylhydrazine (INH)], pyrazinamide, and ethambutol, among other drug therapies. To facilitate and optimize MTB therapeutic selections, a mononuclear phagocyte (MP; monocyte, macrophage, and dendritic cell)-targeted drug delivery strategy was developed. Long-acting nanoformulations of RIF and an INH derivative, pentenyl- INH (INHP), were prepared, and their physicochemical properties were evaluated. This included the evaluation of MP particle uptake and retention, cell viability, and antimicrobial efficacy. Drug levels reached 6 μg/106 cells in human monocyte-derived macrophages (MDMs) for nanoparticle treatments compared with 0.1 μg/106 cells for native …

Intraocular Pressure Changes: An Important Determinant Of The Biocompatibility Of Intravitreous Implants, Ashwin Nair, Ling Zou, Hong Weng, Yi-Ting Tsai, Zhibing Hu, Liping Tang

Bioengineering Faculty Publications - Archive

No abstract provided.

Protective Effects Of Milk Phospholipids Against Uv-Induced Dna Damage In Human Skin Cells, Lan-Anh Nguyen

Master's Theses

Skin cancer is the most common type of cancer in the US. The American Academy of Dermatology estimated that more than 3.5 million new cases of skin cancer are diagnosed in the US each year and 1 in 5 Americans will likely to develop skin cancer in their life time. Most cases of skin cancer are caused by exposure to ultraviolet (UV) radiation from the sun. Some of the most common sunscreen ingredients are unstable and can form harmful radicals upon exposure to UV radiation. There is a strong clinical need for a more stable and effective sunscreen ingredient such …

Intention Tremor And Deficits Of Sensory Feedback Control In Multiple Sclerosis: A Pilot Study, Megan Heenan, Robert A. Scheidt, Douglas Woo, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Background

Intention tremor and dysmetria are leading causes of upper extremity disability in Multiple Sclerosis (MS). The development of effective therapies to reduce tremor and dysmetria is hampered by insufficient understanding of how the distributed, multi-focal lesions associated with MS impact sensorimotor control in the brain. Here we describe a systems-level approach to characterizing sensorimotor control and use this approach to examine how sensory and motor processes are differentially impacted by MS.

Methods

Eight subjects with MS and eight age- and gender-matched healthy control subjects performed visually-guided flexion/extension tasks about the elbow to characterize a sensory feedback control model that …

Vascular Reactivity In Newly-Formed And Mature Arterialized Collateral Capillaries, Sara K. Hellstrom

Master's Theses

Peripheral arterial occlusive disease (PAOD) is a globally-prevalent cardiovascular disease in which atherosclerotic plaques narrow arterial lumen diameters and restrict blood flow to downstream tissues. The impact of these occlusions can be mitigated by collateral vessels that connect parallel arterial branches and act as natural bypasses to maintain perfusion. In animal models that lack collateral arterioles, capillaries that connect terminal arteriolar segments can arterialize and form functional collaterals following an ischemic event; however, in the early stages of development, vasodilation is impaired. We explored the mechanism of impaired vasodilation in arterialized collateral capillaries (ACCs) and pre-existing collaterals (PECs) by evaluating …

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 …

Fabrication, Testing And Analysis Of A Fatigue Sensor For Structural Health Monitoring, Subash Gokanakonda

Dissertations

A novel fatigue monitoring sensor (FMS) is designed, fabricated and tested for detecting and monitoring the fatigue damage and estimating the remaining life of structures and components subjected to cyclic loads. The concept is based on the characteristics of stress / strain life cycle relationship of engineering materials. Sensor consists of alternate slots and strips having different strain magnification factor with respect to the nominal strain. The sensor is designed in such a way that the strips will experience the strain which closely resemble the actual strain distribution in the notch or critical area of the component. The sensor can …

A Highly Adaptive And Cost Effective Second Generation Incubator (Sgi) Towards Educational, Research And Clinical Processes, Yassir H. Al-Sayagh

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Today´s rising demand for more reliable and affordable alternatives to organ transplant has led to a growing market for in vitro tissue culture systems. The main objective of tissue engineering as a whole is to employ human tissue equivalents for commercial use. The state-of-the-art processes for producing these so called tissue models are still very expensive, difficult to produce and time-consuming.

To engineer tissues, in vitro, a three-dimensional support structure commonly termed scaffold is needed. Stem cells are then added to the scaffold. In order for tissue to materialize, the scaffold and the cells must be incubated (cultured) at a …

Comparative Analysis Of Clavicular Tunnel Confìguration For Coracoclavicular Ligament Reconstruction, Mark Omwansa

Masters Theses

A number of coracoclavicular ligament reconstructions are carried out each year and post surgical fractures of the clavicle have been reported. The primary objective of this research is to develop a comparative metrics that compares clavicular tunnel configurations used in coracoclavicular reconstruction techniques. The goal of this comparison is to reduce post surgical failures due to clavicle fractures. The present analysis compared two techniques { a single 3 mm clavicular tunnel and the other double 6 mm tunnels { experimentally, using Four-point bending testing and Finite Element Analysis (FEA). A unique method, slicing, was used to create an FE clavicle …

The Effect Of Artery Bifurcation Angles On Fluid Flow And Wall Shear Stress In The Middle Cerebral Artery, Zachary Ramey Jones

Master's Theses

Saccular aneurysms are the abnormal plastic deformation of veins and arteries that can lead to lethal thrombus genesis or internal hemorrhaging. Medication and surgery greatly reduce the mortality rates, but treatment is limited by predicting who will develop aneurysms. A common location for saccular aneurysm genesis is at the main middle cerebral artery (MCA) bifurcation. The main MCA bifurcation is comprised of the M1 MCA segment, parent artery, and two M2 segments, daughter arteries. Studies have found that the lateral angle (LA) ratio of the MCA bifurcation is correlated with aneurysm formation. The LA ratio is defined as the angle …

Smooth Muscle Cell Organization In The Stem Region Of The Gracilis Collateral Circulation In Balb/C Mice, Laura Lenae Burckhardt

Biomedical Engineering

Of the approximately 8 million Americans who suffer from ischemic peripheral arterial occlusive disease (PAOD), many present with intermittent claudication, or pain associated with exercise. Impaired vasodilation of resistance vessels is a potential explanation for this symptom. Occluded arteries can lead to increased flow through collateral vessels, which function as natural bypasses around the obstruction. This increase in blood flow and resulting shear stress can cause outward remodeling, or arteriogenesis, which improves the efficacy of collaterals. However, following femoral artery ligation in a mouse model of chronic ischemia, vasodilation in the stem region of collateral vessels is impaired at day …

Development Of A Transport System For Advancing Tissue Engineering And Cell Identification, Suzanne Mae Tabbaa

All Dissertations

This work centers on the development of a novel passive transport system for two tissue engineering applications – cell distribution and cell separation. This approach relies on a wicking fiber-based system, derived from the textile field that functions by directing and maintaining transport of cells as well as fluids and biomolecules. This system has the ability to enhance cell movement for both the purpose of cell seeding distribution as well as to isolate specific cell types from heterogeneous cell populations.

The success of spinal fusions and large bone defects is often limited by the decreased surrounding vasculature and the ability …

Fabrication And Characterization Of Antioxidant Loaded Liposomes., Brian Gettler

Electronic Theses and Dissertations

Radiation exposure is both a major obstacle in space exploration and an occupational hazard for various careers causing DNA damage and ROS. In order to reduce the effects of radiation, the primary and most explored approach has been focused around mitigation in terms of exposure duration, exposure intensity, and shielding usage. In some situations none of these reduction strategies were viable and so the use of antioxidants is being explored as an alternate strategy for therapeutic purposes. One such antioxidant is curcumin, otherwise known as diferuloylmethane, is a component of turmeric with both antioxidant properties and anti-inflammatory properties. Another antioxidant …

Development Of A Novel Device For The Perfusion Driven Decellularization Of Skeletal Muscle, Benjamin Kasukonis

Graduate Theses and Dissertations

Decellularization of skeletal muscle is a process that removes cellular components of skeletal muscle tissue while leaving behind the intact extracellular matrix (ECM). Skeletal muscle ECM is currently being studied as a biologic scaffold for repairing volumetric muscle loss (VML) because the removal of cells greatly reduces the antigenicity of the donor tissue. Decellularization usually relies on passive diffusion of detergents, surfactants and/or osmotic solutions to strip cells from the ECM. However, passive diffusion alone is usually not sufficient for complete removal of cells from the interior of large pieces of skeletal muscle using detergents, such as sodium dodecyl sulfate …

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 …

Low Molecular Weight Glucosamine/L-Lactide Copolymers As Potential Carriers For The Development Of A Sustained Rifampicin Release System: Mycobacterium Smegmatis As A Tuberculosis Model, Jorge Ragusa

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Tuberculosis, a highly contagious disease, ranks as the second leading cause of death from an infectious disease, and remains a major global health problem. In 2013, 9 million new cases were diagnosed and 1.5 million people died worldwide from tuberculosis. This dissertation aims at developing a new, ultrafine particle-based efficient antibiotic delivery system for the treatment of tuberculosis. The carrier material to make the rifampicin (RIF)-loaded particles is a low molecular weight star-shaped polymer produced from glucosamine (molecular core building unit) and L-lactide (GluN-LLA). Stable particles with a very high 50% drug loading capacity were made via electrohydrodynamic atomization. Prolonged …

Designing A Biomimetic Testing Platform For Actuators In A Series-Elastic Co-Contraction System, Ryan Tyler Schroeder

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actuators determine the performance of robotic systems at the most intimate of levels. As a result, much work has been done to assess the performance of different actuator systems. However, biomimetics has not previously been utilized as a pretext for tuning a series elastic actuator system with the purpose of designing an empirical testing platform. Thus, an artificial muscle tendon system has been developed in order to assess the performance of two distinct actuator types: (1) direct current electromagnetic motors and (2) ultrasonic rotary piezoelectric motors. Because the design of the system takes advantage of biomimetic operating principles such as …

Development Of A Heart Rate Variability Measurement System Using Embedded Electronics, Naresh Kumar Velmurugan

Graduate Theses and Dissertations

Recent advances in embedded electronics have a remarkable influence on the health care system. One of the most important applications is to monitor the health care of the patients at anytime and anyplace. In the last two decades, many researchers have focused mainly on heart rate variability (HRV) measurements. Patient's heart rate variability should be continuously monitored to help them in case of emergency. Under these circumstances, patients are required to have a HRV measuring kit for a constant observation.

The proposed project focuses on the development of a heart rate variability measurement system with the use of embedded electronics. …

Development And Characterization Of An Autologous Whole Cell Breast Cancer Vaccine, Samantha Leigh Kurtz

Graduate Theses and Dissertations

Approximately 40,000 women will die from breast cancer in the United States in 2014. About 90% of these deaths will be due to metastases, rather than the primary tumor and majority of metastases are due to the recurrence and progression of non-metastatic disease. Current adjuvant treatments, such as chemotherapy and radiation, have severe side effects and may result in overtreatment and drug resistance.

Since greater than 90% of patients are diagnosed between stages I-III and have minimal residual disease after treatment, there is an opportunity to treat patients with an autologous breast cancer vaccine. Autologous vaccines under development have a …

Reversible Blockade Of Complex I Or Inhibition Of Pkcβ Reduces Activation And Mitochondria Translocation Of P66Shc To Preserve Cardiac Function After Ischemia, Meiying Yang, David F. Stowe, Kenechukwu B. Udoh, James S. Heisner, Amadou K.S. Camara

Biomedical Engineering Faculty Research and Publications

Aim

Excess mitochondrial reactive oxygen species (mROS) play a vital role in cardiac ischemia reperfusion (IR) injury. P66^Shc, a splice variant of the ShcA adaptor protein family, enhances mROS production by oxidizing reduced cytochrome c to yield H₂O₂. Ablation of p66^Shc protects against IR injury, but it is unknown if and when p66^Shc is activated during cardiac ischemia and/or reperfusion and if attenuating complex I electron transfer or deactivating PKCβ alters p66^Shc activation during IR is associated with cardioprotection.

Methods

Isolated guinea pig hearts were perfused and subjected to increasing periods …