Biomedical Engineering and Bioengineering Commons^™

Biomechanics Of Prosthetic Knee Systems : Role Of Dampening And Energy Storage Systems, Hande Argunsah Bayram

ETD Archive

One significant drawback of the commercial passive and microprocessored prosthetic devices, the inability of delivering positive energy when needed, is due to the absence of the knee flexion during stance phase. Moreover, consequences such as circumduction and disturbed gait pattern take place due to the improper energy flow at the knee and the absence of the positive energy delivery during the swing phase. Current generation powered design has solved these problems by delivering the needed energy with heavy battery demanding motors, which increase the mass of the device significantly. Hence, the gait quality of transfemoral amputees has not improved significantly …

Scalp Eeg And Tms Based Electrophysiological Study Of Brain Function Of Motor Control In Aging, Mehmed Satuk Bayram

ETD Archive

Voluntary movements of human body are controlled by the brain through corticomuscular pathways. Although neuromuscular control mechanisms of voluntary movements have been studied extensively, many remain to be learned, especially neuromuscular adaptations related to clinical conditions such as neurological disorders and aging. This research aims at a better understanding of functional connection between the brain and muscle during voluntary motor activities in aging and the extent to which this connection can be changed by training the neuromuscular system. Three research projects were conducted to achieve this aim. The analyses in the first two projects are based on comparisons of non-invasive …

An In Silico Liver: Model Of Gluconeogenesis, Elie R. Chalhoub

ETD Archive

An in silico liver was developed in attempt to represent the in vivo state of the fasted liver. It featured two conceptual models. The first one represented carbohydrate metabolism of the human liver, which included the heterogeneous nature of the liver by incorporating spatial variation of key enzyme activities. This model was able to predict the overall fluxes in tissue and the effect of high intensity exercise on the various hepatic fluxes. A second model of hepatic metabolism was developed to represent the complex interplay between gluconeogenesis, lipid metabolism, and alcohol metabolism in the fasted rat liver. Biochemical pathways are …

A Robotic Neuro-Musculoskeletal Simulator For Spine Research, Robb W. Colbrunn

ETD Archive

An influential conceptual framework advanced by Panjabi represents the living spine as a complex neuromusculoskeletal system whose biomechanical functioning is rather finely dependent upon the interactions among and between three principal subsystems: the passive musculoskeletal subsystem (osteoligamentous spine plus passive mechanical contributions of the muscles), the active musculoskeletal subsystem (muscles and tendons), and the neural and feedback subsystem (neural control centers and feedback elements such as mechanoreceptors located in the soft tissues) [1]. The interplay between subsystems readily encourages "thought experiments" of how pathologic changes in one subsystem might influence another--for example, prompting one to speculate how painful arthritic changes …

Radial Diffusion Of Florescein Molecules (376 Da) In Canine Bone Tissue, Daniel O'Conor

ETD Archive

No abstract provided.

Lipid Production By Scenedesmus Dimorphus: Comparison Of Extraction Techniques And Effect Of Sodium Nitrate Concentration, Bahareh Kanani

ETD Archive

No abstract provided.

Synthesis And Characterization Of Ph-Responsive Elastin-Like Polypeptides With Different Configurations, Mingjie Tang

ETD Archive

Elastin-like polypeptides (ELP) are environmentally responsive polymers that exhibit phase transition behavior in response to various stimuli such as temperature, pH and irradiation. In this work, we focused on pH-responsive ELPs. It has been shown that pH value, configurations of ELPs, ELP concentration, and salt concentration can impact the phase transition behavior of pH-responsive ELPs. Quantitative models have been developed to engineer various linear ELPs, but there has not been any detailed study for engineering ionizable ELP with non-linear configurations. In this study, we designed, synthesized, and characterized pH-responsive ELPs with two different configurations. One is linear ELP, (GVGVPGEGVPGVGVP)12, and …

External Control Interface, Dynamic Modeling And Parameter Estimation Of A Research Treadmill, Omer Sirin

ETD Archive

Treadmills providing linear continuous movement are used for robotic testing of prostheses in order to study their operating characteristics. However, traditional exercise treadmills are not able to simulate various conditions such as avoiding an obstacle, climbing, descending, reversing direction, or stopping instantly. The focus of this thesis is to examine control algorithms (position, speed and force) for the drive mechanism of a research treadmill to fulll the gap in the situations described above. The system consists of a power supply, a computer with Matlab, and the treadmill that includes a DC motor, a pulley and belt. Also, an external encoder …

Bench-Top Validation Of "Intelligent" Mouth Guard, Alper Aksu

ETD Archive

Concussion is the signature athletics injury of the 21st Century. Scientists are hard at work monitoring effects of hard impacts on the human brain. However, existing tools and devices are inadequate to screen the effects. Hence, a new approach is required to accurately quantify peak values of head impacts or concussions and relate these values to clinical brain health outcomes. A new head impact dosimeter, the "Intelligent Mouth Guard" (IMG) has been developed and can be conveniently located inside the mouth. In this study, the IMG printed circuit board (PCB) including four (4) high-quality shock resistant sensors has been developed …

Scaffold Composition And Architecture Critically Regulate Extracellular Matrix Synthesis By Cardiomyocytes, Arsela Gishto

ETD Archive

Heart failure accounts for over 5 million cases in the U.S. A major onset of this is myocardial infarction, which causes the myocardium to loose cardiomyocytes and transform into a scar tissue. Given that the adult infarcted cardiac tissue has a limited ability to regenerate, alternative methods to restore the damaged area need to be developed. The goal of these approaches is to design an optimal scaffold that can retain and deliver cardiomyocytes at the site of damaged myocardium. This tissue engineering approach would allow cardiac reconstruction by replacing the lost cardiomyocytes, delivering the required biomolecules, as well as remodeling …

Computational Fluid Dynamics Modeling Of A Gravity Settler For Algae Dewatering, Scott A. Hug

ETD Archive

Algae are the future of lipid sources for biodiesel production. Algae can produce more biodiesel than soybean and canola oil and can be grown in more diverse locations. Algae concentrations are naturally around 0.1 by weight. Enough water must be removed for the algae level to reach 5 , the minimum concentration in which lipids can be used in the transesterification process for biofuel production is 5 . Current dewatering methods involve the use of settling tanks and centrifugation. The costs of centrifugation limit the commercial viability of algae based biodiesel. A novel inclined gravity settler design at Cleveland State …

Moving Horizon Estimation With Dynamic Programming, Mohan Kumar Ramalingam

ETD Archive

Moving Horizon Estimation(MHE) is a optimization based strategy to state estimation. It involves computation of arrival cost, a penalty term, based on the MHE cost function. Minimization of this arrival cost is done through various methods. All these methods use nonlinear programming optimization technique which gives the estimate. The main idea of MHE revolves around minimizing the estimation cost function. The cost function is dependent on prediction error computation from data and arrival cost summarization. The major issue that hampers the MHE is choosing the arrival cost for ensuring stability of the overall estimation and computational time. In order to …

A Microfluidic Platform To Quantify Spatio-Temporal Diffusion Of Chemo-Gradients Within 3d Scaffolds: Applications In Axonal Biology, Michael A. Sawonik

ETD Archive

Axonal outgrowth and guidance play an important role in wiring the developing and regenerating nervous system. The critical role of biomolecular gradients in facilitating this axonal sensitivity and directionality along specific trajectories needs to be elucidated for designing effective therapeutic treatments under injury or disease conditions. However, previous in vitro approaches based on micropipette assay or gel-turning assay proved to be unsuitable or inefficient for precise generation and quantification of diffusive gradients. In this study, we utilized a microfluidic device to generate and quantify physiologically-relevant biomolecular gradients in a simple and reliable manner. Using a combination of computational and experimental …

Micromechanical Analysis Of Nanoparticle-Reinforced Dental Composites, Yi Hua, Linxia Gu, Hidehiko Watanabe

Department of Mechanical and Materials Engineering: Faculty Publications

The mechanical behavior of TiO₂ nanoparticle-reinforced resin-based dental composites was characterized in this work using a three-dimensional nanoscale representative volume element. The impacts of nanoparticle volume fraction, aspect ratio, stiffness, and interphase zone between the resin matrix and nanoparticle on the bulk properties of the composite were characterized. Results clearly demonstrated the mechanical advantage of nanocomposites in comparison to microfiber-reinforced composites. The bulk response of the nanocomposite could be further enhanced with the increased nanoparticle volume fraction, or aspect ratio, while the influence of nanoparticle stiffness was minimal. The effective Young’s modulus and yield strength of the composite was …

Nonlinear Granger Causality And Its Application In Decoding Of Human Reaching Intentions, Mengting Liu

Doctoral Dissertations

Multi-electrode recording is a key technology that allows the brain mechanisms of decision making, cognition, and their breakdown in diseases to be studied from a network perspective. As the hypotheses concerning the role of neural interactions in cognitive paradigms become increasingly more elaborate, the ability to evaluate the direction of neural interactions in neural networks holds the key to distinguishing their functional significance.

Granger Causality (GC) is used to detect the directional influence of signals between multiple locations. To extract the nonlinear directional flow, GC was completed through a nonlinear predictive approach using radial basis functions (RBF). Furthermore, to obtain …

Performance Of Wavelet Denoising And Automatic Detection Of Action Potentials On Simulated And Real Electrneurographic Recordings, Manikandan Ravi

Bioengineering Theses - Archive

About 1 in 200 people living in the U.S have had an amputation at some stage in their lives. Development of neurally controlled artificial limb prosthesis with the ability to finely control motor activity continues to prove difficult for researchers in the field. One approach is to use the signals obtained from the peripheral nerves by placing an intraneural electrode in the nerve. Since this signal is very noisy, much of the useful information is either lost or buried in the noise even after FIR filtering. Furthermore, there is a need for fast, automated detection of action potentials in order …

Long Gap Peripheral Nerve Reconstruction Using Decellularized Nerve Grafts, Srikanth Vasudevan

Bioengineering Dissertations - Archive

Peripheral nerve injuries that arise as a result of trauma, tumor excision or birth can adversely affect the quality of patient life, leading to lifelong disabilities in some cases. Autologous nerve grafts are the clinical "gold standard" for long gap nerve repair, and allogeneic nerve grafts are considered the next best treatment option. Despite having numerous benefits, autologous nerve grafts are associated with limited supply, longer operation time, risk of infection, painful neuroma formation and most importantly, loss of function at the donor site. Allogeneic nerve grafts require transient immunosuppression, which exposes the patients to risks of infection, toxicity and …

Protoporphyrin Ix (Ppix)-Conjugated Self-Lighting Nanoparticles For Photodynamic Therapy: Synthesis And Characterization, Homa Homayoni

Bioengineering Dissertations - Archive

In Photodynamic therapy (PDT) PDT, cancer destruction relies on applying a photosensitizing drug (PS) followed by light. Absorbed light can activate the PS to transfer energy to existing molecules and substrates or to oxygen to generate singlet oxygen which are highly toxic to cells. Protophorphyrin IX (PpIX) is a photosensitizers (PSs) which has FDA approval and an absorbance near the Soret band which is 10 times stronger than the absorbance in Q-band (600nm). Our goal was to design a modality to eliminate of external blue light in addition to increasing the drug's water dispersion which finally may result in enhancing …

An Investigation Of Concurrent Variations In Blood Oxygen Saturation And Cerebral Blood Flow During Apnea, Jennifer Swittens

Bioengineering Theses - Archive

Sleep apnea derived from Greek word "apnoia" which means "without air or temporary interruption in breathing", is a sleep - associated breathing disorder that involves a decrease or complete stop in airflow despite a constant effort to breathe. It is estimated that sleep apnea is prevalent in the US in 18 million people and is approximately 6% of the population.This thesis aims to study the physiological effects of sleep apnea on cerebral blood flow (CBF) and the percentage oxygen saturation (%SaO2), the effect of duration of apnea episode or a breath hold on CBF and %SaO2 and to derive a …

Establishment And Characterization Of An Animal Model Of Distraction Spinal Cord Injury, Jennifer Elisabeth Stearns Bell

Bioengineering Dissertations - Archive

Scoliosis corrective surgery requires the application of multidirectional stress forces to the spinal cord, including those of distraction, in addition to the application of fixation rods for correction of the curved spine deformity. If excessive, spine distraction may result in the development of new neurologic deficits, some as severe as permanent paralysis. Intraoperative monitoring is used to alert the surgeon to possible complications; however, the complex nature of spinal cord injury (SCI) involves a primary mechanical insult to the tissue and/or vasculature that may go undetected by monitoring. This is followed by the activation of widespread secondary injury mechanisms. The …