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Full-Text Articles in Biomedical Engineering and Bioengineering

Feasibility Of Using An Equilibrium Point Strategy To Control Reaching Movements Of Paralyzed Arms With Functional Electrical Stimulation, Matthew Huffman Jan 2018

Feasibility Of Using An Equilibrium Point Strategy To Control Reaching Movements Of Paralyzed Arms With Functional Electrical Stimulation, Matthew Huffman

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Functional electrical stimulation (FES) is a technology capable of improving the quality of life for those with the loss of limb movement related to spinal cord injuries. Individuals with high-level tetraplegia, in particular, have lost all movement capabilities below the neck. FES has shown promise in bypassing spinal cord damage by sending electrical impulses directly to a nerve or muscle to trigger a desired function. Despite advancements in FES, full-arm reaching motions have not been achieved, leaving patients unable to perform fundamental tasks such as eating and grooming. To overcome the inability in current FES models to achieve multi-joint coordination, …


Characterizing The Effects Of High-Intensity Exercise On Balance And Gait Under Dual-Task Conditions In Parkinson’S Disease, El Iva Baron Jan 2018

Characterizing The Effects Of High-Intensity Exercise On Balance And Gait Under Dual-Task Conditions In Parkinson’S Disease, El Iva Baron

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Parkinson’s disease (PD) is a neurodegenerative disorder, characterized by four cardinal motor symptoms including bradykinesia, tremor, rigidity, and postural instability, and non-motor symptoms including cognitive impairment. Daily activities, such as walking and maintaining balance, are impacted due to impairments in motor function, and are further exacerbated with the addition of cognitive loading, or dual-tasking (DT). High-intensity exercise has demonstrated centrally-mediated improvements of PD symptoms, with additional positive effects on overall health. The goal of this project was to identify changes in dynamic balance recovery and gait function under conditions with and without increased cognitive load after a high-intensity exercise intervention …


Neuromuscular Reflex Control For Prostheses And Exoskeletons, Sandra K. Hnat Jan 2018

Neuromuscular Reflex Control For Prostheses And Exoskeletons, Sandra K. Hnat

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Recent powered lower-limb prosthetic and orthotic (P/O) devices aim to restore legged mobility for persons with an amputation or spinal cord injury. Though various control strategies have been proposed for these devices, specifically finite-state impedance controllers, natural gait mechanics are not usually achieved. The goal of this project was to invent a biologically-inspired controller for powered P/O devices. We hypothesize that a more muscle-like actuation system, including spinal reflexes and vestibular feedback, can achieve able-bodied walking and also respond to outside perturbations. The outputs of the Virtual Muscle Reflex (VMR) controller are joint torque commands, sent to the electric motors …


The Effect Of Cognitive Limb Embodiment On Vascular Physiological Response, Hala Elsir Mustafa Osman Jan 2018

The Effect Of Cognitive Limb Embodiment On Vascular Physiological Response, Hala Elsir Mustafa Osman

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The rubber hand illusion (RHI) is a visual-tactile perceptual illusion commonly used to study body ownership. In this paradigm, a rubber hand is positioned in front of a participant, and the person’s real hand is hidden from sight behind a barrier. When the real hand and the rubber hand are stroked synchronously, individuals perceive the rubber hand as if it were their own; it becomes “embodied.” This illusory experience of body ownership is associated with multimodal integration of touch and vision. From these visual-tactile-cognitive mechanisms, we establish that our hands belong to us when what we see matches what we …


High-Throughput Metabolism-Induced Toxicity Assays On A 384-Pillar Plate, Sooyeion Kang Jan 2018

High-Throughput Metabolism-Induced Toxicity Assays On A 384-Pillar Plate, Sooyeion Kang

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The U.S Environmental Protection Agency (EPA) launched the Transform Tox Testing Challenge in 2016 with the goal of developing practical methods that can be integrated into conventional high-throughput screening (HTS) assays to better predict the toxicity of parent compounds and their metabolites in vivo. In response to this need and to retrofit existing HTS assays for assessing metabolism-induced toxicity of compounds, we have developed a 384-pillar plate that is complementary to traditional 384-well plates and ideally suited for culturing human cells in three dimensions (3D) at a microscale. Briefly, human embryonic kidney (HEK) 293 cells in a mixture of alginate …


A Synthesis Platform For Temperature Responsive Star Polymers, Schmitt J. Richard Jr. Jan 2018

A Synthesis Platform For Temperature Responsive Star Polymers, Schmitt J. Richard Jr.

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Star polymers are a class of branched polymers comprised of several polymer chains extending from a central point. Star polymers have applications in biopharmaceuticals where they have been proposed to be suitable drug delivery vehicles. Star polymers have traditionally been synthesized through chemical synthesis with added functionality provided by grafting on the arms. This complex synthesis can be simplified by using a biosynthetic approach which enables precise control of molecular weight and composition. This approach is demonstrated using star polymers with arms composed of a temperature responsive protein-based polymer termed elastin-like polypeptide (ELP). Star polymers are characterized based on the …


Predictive Simulations Of Gait And Their Application In Prosthesis Design, Anne D. Koelewijin Jan 2018

Predictive Simulations Of Gait And Their Application In Prosthesis Design, Anne D. Koelewijin

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Predictive simulations predict human gait by solving a trajectory optimization problem by minimizing energy expenditure. These simulations could predict the effect of a prosthesis on gait before its use. This dissertation has four aims, to show the application of predictive simulations in prosthesis design and to improve the quality of predictive simulations. Aim 1 was to explain joint moment asymmetry in the knee and hip in gait of persons with a transtibial amputation (TTA gait). Predictive simulations showed that an asymmetric gait required less effort. However, a small effort increase yielded a gait with increased joint moment symmetry and reduced …


Stabilization Of Hypoxia Inducible Factor By Cobalt Chloride Can Alter Renal Transepithelial, Subhra Sankar Nag Jan 2018

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

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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 …


Modeling Liver Diseases Using Hepatic Cell Microarrays, Alexander David Roth Jan 2018

Modeling Liver Diseases Using Hepatic Cell Microarrays, Alexander David Roth

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Hepatocellular carcinoma (HCC) is an invasive and aggressive cancer of the liver that arises due to chronic cirrhosis. Research into understanding HCC has focused on two-dimensional (2D) and three-dimensional (3D) technologies to simulate the liver microenvironment and use animal models to model how HCC affects the rest of the body. 3D hydrogel models are desired because they can mimic the transport behavior observed in vivo by structurally mimicking the extracellular matrix (ECM) without the ethical concerns of animal models. However, hydrogels can be toxic to cells and require optimal procedures for appropriate handling. In this study, we created 3D models …


Advanced Manufacturing Of Titanium Alloys For Biomedical Applications, Nicholas C. Mavros Jan 2018

Advanced Manufacturing Of Titanium Alloys For Biomedical Applications, Nicholas C. Mavros

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In metallurgy, Titanium has been a staple for biomedical purposes. Its low toxicity and alloying versatility make it an attractive choice for medical applications. However, studies have shown the difference in elastic modulus between Titanium alloys (116 GPa) and human bone (40-60 GPa) contribute to long term issues with loose hardware fixation. Additionally, long term studies have shown elements such as Vanadium and Aluminum, which are commonly used in Ti-6Al-4V biomedical alloys, have been linked to neurodegenerative diseases like Alzheimers and Parkinsons. Alternative metals known to be less toxic are being explored as replacements for alloying elements in Titanium alloys. …