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Full-Text Articles in Engineering

Investigation Of Retrieved Cardiac Devices, Anmar Salih, Iosif Papadakis Ktistakis, Spyridon Manganas, Abdul Wase, Tarun Goswami Dec 2019

Investigation Of Retrieved Cardiac Devices, Anmar Salih, Iosif Papadakis Ktistakis, Spyridon Manganas, Abdul Wase, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Damage assessment of lead and pulse generator with various exposure times is important in the development of cardiac devices. Approximately, 92.1 million patients in the US suffer from cardiovascular diseases with an estimated healthcare cost of over $300 billion and at least one million with implantable cardiac devices. These devices are complex and composed on multiple levels and present challenges while assessing the damage. However, the study on the analysis of cardiac devices may lend insight into common damage patterns and improve future cardiac devices design. The objective of this work is to perform a thorough in vivo damage assessment …


Investigation Of A Neuro-Stimulator Retrieved Posthumously, Megan Markl, Rodney J. Gutherie, Tarun Goswami Dec 2019

Investigation Of A Neuro-Stimulator Retrieved Posthumously, Megan Markl, Rodney J. Gutherie, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

A neurostimulator was investigated in this paper posthumously. Device was presented to our anatomical gift program. Investigation was multi-fold and contained visual inspection, using an optical microscope, and mechanical and electrical testing of leads and its insulator. It was concluded that the device could have been damaged during implantation, in vivo, during removal, and/or during transportation to author’s laboratories. The damage observed on the lead insulation is similar to that which can occur due to anchoring of the lead and hardening due to oxidation. Insulation stiffness was determined to be 1/10 of new insulator. The results reported here on the …


Simulation Of Skull Fracture Due To Falls, Anthony Vicini, Tarun Goswami Dec 2019

Simulation Of Skull Fracture Due To Falls, Anthony Vicini, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

This study presents novel predictive equations for von Mises stress values of bones in the frontal and lateral regions of the skull. The equations were developed based on results of a finite element model developed during this research. The model was validated for frontal and lateral loading conditions with input values mimetic to fall scenarios. Using neural network processing of the information derived from the model achieved R2 values of 0.9990 for both the stress and deflection. Based on the outcome of the fall victims, a threshold von Mises stress of 40.9 to 46.6 MPa was found to indicate skull …


Deep Brain Stimulation: Prediction Model For Volume Of Tissue Stimulated, Melissa Jones, Tarun Goswami Nov 2019

Deep Brain Stimulation: Prediction Model For Volume Of Tissue Stimulated, Melissa Jones, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

An attempt has been made to understand deep brain stimulation in humans via marketable devices that are approved by the US Food and Drug Administration. The electrode characteristics were presented to influence the volume of tissue stimulated. Experimental data were digitized and VTS data were presented a function of electrode diameter, aspect ratio, applied current, pulse duration, voltage and frequency. Amongst other trends voltage and VTS were found to exhibit a three-stage relation, where Stage II characteristics were represented by a linear equation. It is in this stage, the VTS was found to be stable and where the most effective …


Stress Shielding In Cemented Hip Implants Assessed From Computed Tomography, Bharadwaj Cheruvu, Indresh Venkatarayappa, Tarun Goswami May 2019

Stress Shielding In Cemented Hip Implants Assessed From Computed Tomography, Bharadwaj Cheruvu, Indresh Venkatarayappa, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Background: Aseptic loosening is the major cause of revisions for hip replacement. This mode of failure is often caused by stress shielding. Stress shielding in the femur occurs when some of the loads are taken by the prosthesis and shielded from going to the bone. There is little information regarding the stress shielding among cemented hip implants. Purpose: The purpose of this study is to investigate the effect of stress shielding on the proximal femur with a femoral prosthesis. Methods: A patient had undergone open reduction and internal fixation (ORIF) due to a comminuted reversed oblique fracture of the right …


Chondroitin Sulfate Hydrogels For Total Wound Care Devices, Tushar Goswami Jan 2019

Chondroitin Sulfate Hydrogels For Total Wound Care Devices, Tushar Goswami

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Chondroitin sulfate (CS) is a naturally occurring bio-polymer found in areas of high cartilage in mammals. In directed applications, such as hydrogels, CS can be used to impact keratinocyte growth cycles. In this work, CS based hydrogels were utilized to accelerate wound healing and, in conjunction with a graphene sensor, monitor wound fluid pH. The hydrogels were cast onto a graphene field effect transistor (GFET) to obtain the benefits of the hydrogel wound healing capabilities, while also utilizing the pH sensitivity of the graphene. Results showed that the hydrogel caused a fivefold increase in cell size over the course of …


Differential Microrna Expression In Barrett's Esophagus Correlates With Regulation Of Posterior Homeotic Genes, Reilly June Clark Jan 2019

Differential Microrna Expression In Barrett's Esophagus Correlates With Regulation Of Posterior Homeotic Genes, Reilly June Clark

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Barrett’s Esophagus (BE) is characterized by the appearance of an intestinal-like epithelium in the distal esophagus. The molecular mechanisms behind BE development are unknown. BE is often preceded by Gastroesophageal Reflux Disease (GERD) and predisposes patients to esophageal adenocarcinoma (EAC). Due to the high mortality rate associated with EAC, BE patients are continuously monitored through upper endoscopy with biopsy for progression to low grade dysplasia (LGD), high grade dysplasia, and EAC. This monitoring technique poses numerous risks, so alternative surveillance and diagnostic techniques for BE pathogenesis are continually studied. microRNA biomarkers in BE pathogenesis may provide alternative means of diagnosis …


Mechanical Stresses On Nasal Mucosa Using Nose-On-Chip Model, Zachary Edward Brooks Jan 2019

Mechanical Stresses On Nasal Mucosa Using Nose-On-Chip Model, Zachary Edward Brooks

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The objective of this research was to design and fabricate a nose-on-chip device and bi-directional airflow system that models flow within the nasal cavity to investigate how airflow induced mechanical stresses impact nasal secretion rates and cytoskeletal remodeling. This research hypothesizes that the airflow induced shear stresses on the nasal mucosa will influence mucus production and the cytoskeleton of the cells. The RPMI 2650 cell line was used to model the nasal mucosa. The system was used to replicate the wall shear stresses (WSS) and wall shear forces (WSF) present in the anterior region of the nose. The WSS and …


Mitochondria-Dependent Cellular Toxicity Of Α-Synuclein Modeled In Yeast, Rajalakshmi Santhanakrishnan Jan 2019

Mitochondria-Dependent Cellular Toxicity Of Α-Synuclein Modeled In Yeast, Rajalakshmi Santhanakrishnan

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Parkinson’s disease is the second most common neurodegenerative disease. This disease is caused by the degeneration of dopaminergic neurons, leading to debilitating motor symptoms and early mortality. The protein α-synuclein (α-syn), encoded by SNCA, misfolds and forms inclusions in Parkinson’s disease brains. When α-syn is overexpressed in yeast, it causes cellular toxicity and an increased number of aggregates, recapitulating the toxic phenotypes observed in humans and animal models. Yeast models are a powerful tool to perform high-throughput overexpression screening to identify modifiers of α-syn toxicity. α-syn causes mitochondrial dysfunction by inhibiting complex I and inducing mitochondrial fragmentation. Prior screening of …


Characterizing Basal-Like Triple Negative Breast Cancer Using Gene Expression Analysis: A Data Mining Approach, Qamar Alsabi Jan 2019

Characterizing Basal-Like Triple Negative Breast Cancer Using Gene Expression Analysis: A Data Mining Approach, Qamar Alsabi

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Triple-negative breast cancer (TNBC) is characterized by the absence of expression of the estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 (HER2). Therefore, TNBC is unresponsive to targeted hormonal therapies, which limits treatment options to nonselective chemotherapeutic agents. Basal-like breast cancers (BLBCs) represent a subset of about 70% of TNBCs, more frequently affecting younger patients, being more prevalent in African-American women and significantly more aggressive than tumors of other molecular subtypes, with high rates of proliferation and extremely poor clinical outcomes. Proper classification of BLBCs using current pathological tools has been a major challenge. Although TNBCs have …


Assessing The Role Of Polyphenols As A Vascular Protectant Against Drug Induced Vascular Injury, Anson Jacob Oommen Jan 2019

Assessing The Role Of Polyphenols As A Vascular Protectant Against Drug Induced Vascular Injury, Anson Jacob Oommen

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Vascular injury is identified during pre-clinical toxicity testing within certain pharmacological classes of drug candidates and induces degenerative and hyperplastic changes in endothelial (ECs) and vascular smooth muscle (VSMCs) cells. This drug-induced vascular injury has been show as a side-effect caused by various classes of drugs, including, antibacterial (e.g., azithromycin), anti-malarial (e.g., quinoline), anti-viral (e.g., anti-hepatitis C virus interferons) and nonsteroidal anti-inflammatory drugs (e.g., ibuprofen), and affects normal cardiovascular function and can further lead to various cardiovascular conditions like arrhythmia, cardiac arrest, high blood pressure, and even heart attack. The search for agents capable of reducing vascular injury side-effects by …


Type 2 Diabetes Leads To Impairment Of Cognitive Flexibility And Disruption Of Excitable Axonal Domains In The Brain, Leonid M. Yermakov Jan 2019

Type 2 Diabetes Leads To Impairment Of Cognitive Flexibility And Disruption Of Excitable Axonal Domains In The Brain, Leonid M. Yermakov

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Type 2 diabetes is a metabolic disease affecting millions of people around the world. Cognitive and mood impairments are among its many debilitating complications, but disease mechanism(s) remain elusive. Here, we present a series of behavioral tasks that demonstrate impairment of cognitive flexibility in db/db mice, a commonly used type 2 diabetes model. Using immunohistochemistry, we demonstrate disruption of axon initial segments (AIS) and nodes of Ranvier, excitable axonal domains regulating neuronal output, in brain regions associated with cognitive and mood impairments. Finally, we present results of exercise treatment that ameliorates AIS disruption in these animals. Establishing cognitive flexibility deficits …


Biomarker-Performance Associations During Nutritional And Exercise Intervention In Air Force Personnel, Jennifer Jurcsisn Jan 2019

Biomarker-Performance Associations During Nutritional And Exercise Intervention In Air Force Personnel, Jennifer Jurcsisn

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This study evaluated the combined effects of an exercise intervention and nutritional supplement on biomarkers of stress and resilience, and the relationships of those markers with physical and cognitive performance. 130 healthy Active-Duty Air Force (AF) personnel were recruited to participate in a double-blind, placebo controlled 12-week exercise and nutritional intervention. Serum was collected at basal and high stress conditions pre- and post-intervention to track the following biomarkers: cortisol, dehydroepiandrosterone-sulfate (DHEA-S), norepinephrine (NE), neuropeptide Y (NPY), and serotonin. The exercise intervention significantly attenuated the cortisol response and peak stress cortisol levels. The nutritional intervention decreased peak stress NE. The selected …


Computational Simulation Of A Femoral Nail Fracture, Stephen Charles Whatley Jan 2019

Computational Simulation Of A Femoral Nail Fracture, Stephen Charles Whatley

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Every year in the United States roughly 300,000 people over the age of 65 suffer from a hip fracture. Ninety five percent of which are the result from a fall. The resulting hip fracture can be classified into several categories of fracture. Depending on the damage the patient could be implanted with a femoral nail device to assist in their recovery. These devices can, however, have complications during recovery. In some cases, these nails can have a failure rate as high as 10%. When failure occurs, extensive investigations are needed to determine the causes of failure. These investigations involve physical …


Characterization Of In-Vivo Damage In Implantable Cardiac Devices And The Lead Residual Properties, Anmar Mahdi Salih Jan 2019

Characterization Of In-Vivo Damage In Implantable Cardiac Devices And The Lead Residual Properties, Anmar Mahdi Salih

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Approximately, 92.1 million patients in the US suffer from cardiovascular diseases with an estimated healthcare cost of over $300 billion; out of which at least one million patients have Cardiac Implantable Electronics Devices (CIED). CIED represented by pacemakers, Implantable Cardioversion Defibrillator (ICD), and Cardiac Resynchronization Therapy (CRT) are exposed to in-vivo damage. These damages are complex and composed on multiple levels and present challenges while assessing their combined extent. Since 2004, more than one hundred recalls were reported for cardiac devices. ICD devices had the majority with 40.8% recalls, pacemaker recall percentage was 14.5%, CRT recall percentage was12.7%, leads recalls …


Monitoring Cerebral Functional Response Using Scmos-Based High Density Near Infrared Spectroscopic Imaging, Dharminder Singh Langri Jan 2019

Monitoring Cerebral Functional Response Using Scmos-Based High Density Near Infrared Spectroscopic Imaging, Dharminder Singh Langri

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Neurovascular coupling is an important concept that indicates the direct link between neuronal electrical firing with the vascular hemodynamic changes. Functional Near Infrared Spectroscopy (fNIRS) can measure changes in cerebral vascular parameters of oxy-hemoglobin and deoxyhemoglobin concentrations and thus can provide neuronal activity through neurovascular coupling. Currently many commercial fNIRS devices are available, but they are limited by the number of channels (usually having only 8 detectors), which can limit the sensitivity, contrast, and resolution of imaging. High-density imaging can improve sensitivity, contrast, and resolution by providing many measurements and averaging the signals originating from the target cerebral focus area …