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Articles 1 - 30 of 284

Full-Text Articles in Biomedical Engineering and Bioengineering

Vergence Eye Movement Parameters For Pre/Post-Obvat And Sham Therapy On Binocularly Normal Controls, Joel V. Rajah May 2019

Vergence Eye Movement Parameters For Pre/Post-Obvat And Sham Therapy On Binocularly Normal Controls, Joel V. Rajah

Theses

Vergence is the disjunctive movement of the eyes to maintain single binocular vision. Vergence eye movements are necessary to maintain the object of interest on the fovea of each eye as an individual looks from one object to another. Recent studies show that office based vergence/accommodative therapy (OBVAT) is an effective treatment for the binocular dysfunction known as convergence insufficiency. This study was performed to investigate the changes in oculomotor parameters parameter data for pre- and post-therapy subjects who are binocularly normal controls. A haploscope was used to collect eye movement data pre- and post-therapy. The analysis of the ...


Performance Enhancement Of Human Motion Based Piezoelectric Energy Harvesters, Iman Izadgoshasb Jan 2019

Performance Enhancement Of Human Motion Based Piezoelectric Energy Harvesters, Iman Izadgoshasb

Theses

Harvesting electricity from human motions using piezoelectric materials is attracting the attention of many researchers in recent years. These harvesters can potentially power portable electronic devices without the need of external power sources.

The aim of this thesis was to improve the efficiency of piezoelectric energy harvesting from human motions. To achieve this, optimising orientation of piezoelectric cantilever beam investigated; the new mechanism consisting of double pendulum system was studied and finally the new shape design of cantilever was proposed to generate multi resonance peaks. These achievements may help to improve the efficiency of piezoelectric energy harvesters in the future.


Head Impacts In The A7fl, Stephen Mcgeever May 2018

Head Impacts In The A7fl, Stephen Mcgeever

Theses

The American 7s Football League (A7FL) is a semi professional football league that does not use helmets or pads. The theory is that the game is safer without helmets and pads because players feel more vulnerable and use a different tackling technique to protect themselves. Rather than lowering and leading with their head when the players tackle, as many helmeted football players do, A7FL players primarily use their arms to wrap the opponent up. A7FL players were given Vector mouth guards designed by Athlete Intelligence to wear. These mouth guards have built in tri-axial accelerometers to record impact data, which ...


Changes In Nadph Oxidase (Nox) Protein Isoforms And Downstream Reactions As Function Of Time And Overpressure In Blast Tbi, Smit Prakash Shah Jan 2018

Changes In Nadph Oxidase (Nox) Protein Isoforms And Downstream Reactions As Function Of Time And Overpressure In Blast Tbi, Smit Prakash Shah

Theses

No abstract provided.


Carbon Fiber Electrodes For In Vivo Neural Recording, Esma Cetinkaya Dec 2017

Carbon Fiber Electrodes For In Vivo Neural Recording, Esma Cetinkaya

Theses

Multi-channel micro electrodes for neural recording is a growing field that thrives on novel materials and fabrication techniques offered by micro fabrication technology. The material and the design of microelectrodes have a critical role on the qualit


Spatial And Temporal Deformation Pattern Of The Brain From Blunt Trauma, Abdus Ali Aug 2017

Spatial And Temporal Deformation Pattern Of The Brain From Blunt Trauma, Abdus Ali

Theses

It is widely accepted that under extreme loadings the soft tissue of the brain will deform inside the skull, creating large amounts of both stress and strain on the tissue. This can result in a focal injury, or in the case of acceleration and decelerat


Interaction Of Voluntary Activity And Functional Electrical Stimulation In The Upper Extremity As A Method For Short-Term Alteration Of Corticospinal Excitability And Force Control, Katherine Maia Gerton Aug 2017

Interaction Of Voluntary Activity And Functional Electrical Stimulation In The Upper Extremity As A Method For Short-Term Alteration Of Corticospinal Excitability And Force Control, Katherine Maia Gerton

Theses

Repetitive movement training (RMT) is a well-established method for rehabilitating functional movement. However, many stroke survivors are not able to participate in RMT for the necessary duration to produce results due to rapid muscle fatigue or inabi


Subject And Group Level Changes And Comparison In Functional Connectivity Under Low Vs. High Cognitively Demanding Naturalistic Viewing Conditions Using Fmri, Rakibul Hafiz Aug 2017

Subject And Group Level Changes And Comparison In Functional Connectivity Under Low Vs. High Cognitively Demanding Naturalistic Viewing Conditions Using Fmri, Rakibul Hafiz

Theses

Resting State fMRI is used extensively for analysing brain regions. fMRI is also used to determine task induced activations from cerebral networks. This study involves both rest and task activation data and implements statistical methods applied on Blo


Profiling The Neurovascular Cell Interactions In Alcohol Exposure And Hiv-1 Infection, Agnieszka Agas May 2017

Profiling The Neurovascular Cell Interactions In Alcohol Exposure And Hiv-1 Infection, Agnieszka Agas

Theses

Alcohol use is known to exacerbate the progression of human immunodeficiency virus associated acquired immunodeficiency syndrome or HIV/AIDS in the brain, known as the NeuroAIDS. The mechanisms of this accelerated progression are still poorly understoo


Experimental Study Of Bubble Rupture During Shock-Fluid Interaction, Subhalakshmi Chandrasekaran May 2017

Experimental Study Of Bubble Rupture During Shock-Fluid Interaction, Subhalakshmi Chandrasekaran

Theses

Head injuries are associated with exposure to high energy explosive detonation. There are four distinct types of blast induced neurotrauma (BINT): 1) these caused by supersonic shock waves propagating in the atmosphere (primary), 2) high velocity impac


Measurement Of Finger Coordination During A Motor Learning Task, Robert Ebel May 2017

Measurement Of Finger Coordination During A Motor Learning Task, Robert Ebel

Theses

The focus of this study is to observe the changes in whole hand grasp strategy, in healthy subjects, over time in a series of isometric force control learning tasks. During a series of trials with real-time visual feedback of the five finger forces, su


Denoising Techniques Reveal Neural Correlates Of Modulation Masking Release In Auditory Cortex, Sahil Chaubal Dec 2016

Denoising Techniques Reveal Neural Correlates Of Modulation Masking Release In Auditory Cortex, Sahil Chaubal

Theses

Hearing aids allow hearing impaired (HI) individuals to regain auditory perception in quiet settings. However, despite advances in hearing aid technology, HI individuals do not perform as well in situations with background sound as normally hearing (NH


An Electromechanical System For Characterization Of Piezoelectric Materials, Ahmet Sait Asan May 2016

An Electromechanical System For Characterization Of Piezoelectric Materials, Ahmet Sait Asan

Theses

Piezoelectric materials have been used in medical applications for a long time due to their unique characteristics, which is to respond to mechanical stimulation by producing an electrical current and vice versa. They perform a pivotal role in medical applications both for diagnostic and therapeutic purposes. In this regard, characterizing the piezoelectric properties of these materials is crucial for their usage. In this particular study, an electromechanical system for measurement of piezoelectric output signals is designed and tested. The project is motivated by the question: can the piezoelectric properties be characterized by applying different mechanical stimulation waveforms and frequencies. Two ...


Antibacterial Efficacy Of Nanometals In Conjunction With Electrical Stimulus, Syed A. Hussain May 2016

Antibacterial Efficacy Of Nanometals In Conjunction With Electrical Stimulus, Syed A. Hussain

Theses

Hospital related infections generally result from the combined effect of preexisting bacteria on the patient and invasive devices. This demonstrates the significance in improving these medical devices to increase the quality of life of the patients that require them. This study will attempt to evaluate the antibacterial efficacy of nanocopper particles and an electrical stimulus for the usage in medical device development and the hospital environment.

For devices such as catheters, infections typically result from bacteria entering the body from the outside. This is accomplished by bacteria attaching themselves to the exterior of the device and producing biofilm which allows ...


Response Of Stretch-Injured Schwann Cells, Stephanie Iring May 2016

Response Of Stretch-Injured Schwann Cells, Stephanie Iring

Theses

Axon fibers are covered by myelin sheath. After axonal damage, demyelination follows with the production of debris. In the Central Nervous System many studies have been performed to observe and analyze stretch injured axons, but very little has been done to study the white matter axonal tracts, oligodendrocytes. Schwann cells can help take a first look into stretch injured glia cells from the Peripheral nervous system. In order to observe changes in Schwann Cells a stretch injury device is used to produce the effects of severe and moderate injuries. Schwann Cells are stretch injured in both their undifferentiated and differentiated ...


Effect Of Melt Method On Thoracolumbar Connective Tissue, Faria Sanjana May 2016

Effect Of Melt Method On Thoracolumbar Connective Tissue, Faria Sanjana

Theses

Approximately, 31 million adults in the United States suffer from low back pain (LBP). Altered connective tissue structure has been identified in adults with chronic LBP. Numerous novel treatments are being developed targeting the connective tissue and nervous system to relieve people from LBP. One such self-care treatment is the MELT method. The objective of this study was to determine whether thickness of thoracolumbar connective tissue and other biomechanical and viscoelastic properties of myofascial tissue in the low back region change in subjects with chronic LBP as a result of MELT.

Using ultrasound imaging and an algorithm developed in MATLAB ...


Continuum Mechanical Analysis Of Space And Time Dependent Deformation Pattern Of Brain With Blunt Injury, Chen Miao May 2016

Continuum Mechanical Analysis Of Space And Time Dependent Deformation Pattern Of Brain With Blunt Injury, Chen Miao

Theses

Deformation of human brain due to acceleration impact has been widely accepted as the direct connection to the Trauma Brain Injury (TBI). However, the limitation of obtaining deformation data of TBI is a major obstacle to understanding TBI mechanism. This experiment mainly focuses on developing a method to measure deformation pattern of brain with blunt injury. First of all, displacement data of markers on sagittal plane of an injury head model was collected using 3D reconstruction software after an impact test. Second, the displacement data was used to calculate 2D Lagrangian strain tensor and the principal strain. The temporal and ...


Investigating Neural Mechanisms Of Hand Movements In Virtual Reality, Chuang Mu Dec 2015

Investigating Neural Mechanisms Of Hand Movements In Virtual Reality, Chuang Mu

Theses

Mirror visual feedback (MVF), a technique by which movement of one limb is perceived as movement of the contralateral limb, has the capacity to relieve phantom limb pain or promote motor recovery of the upper limbs after stroke (Ramachandran et al., 1995). Functional MRI studies have demonstrated activation of the motor areas in the hemisphere ipsilateral to the moving hand in response to MVF. However, the neural mechanisms of MVF are still unclear. This Electroencephalography (EEG) study was designed to investigate the timing of neural responses to MVF presented in virtual reality. 16 right-handed, neurologically healthy subjects participated in a ...


Rodent Testing Device Surrogate For Shockwave Blast Testing, Anthony C. Misistia Dec 2015

Rodent Testing Device Surrogate For Shockwave Blast Testing, Anthony C. Misistia

Theses

Many laboratories around the world are conduct shockwave blast injury tests on rodents to simulate blast traumatic brain injury (TBI). Each of these laboratories has different techniques for creating the shockwave blasts as well as positioning the rats. There is no device to determine whether or not the rodent animal models actually experiences a true blast wave in a given set up. This device was developed as a method for verifying rodents undergoing true shockwave blasts through biometrics, instrumentation and the basic biomechanical responses a rodent experiences during such tests. Since the goal of shockwave blast testing is to replicate ...


A Study Of Kinematics And Kinetics In Time-Constrained Arm Movements, Oyindamola Owoeye Dec 2015

A Study Of Kinematics And Kinetics In Time-Constrained Arm Movements, Oyindamola Owoeye

Theses

Several studies such as the equilibrium point hypothesis (EPH) purport that the motor signals that descend from the brain instead of encoding muscle torques, influence an existing relationship between muscle torque and body configuration.

In the present study, the possibility of torque depending explicitly on position was tested using a task in which subjects (N=5) moved a simulated weightless frictionless mass through a small (<8 degree) elbow extension in order to move a cursor on a screen to a target location. Each subject completed 720 trials. On ~10% of trials the simulated mass was increased unknown to the subject. The relationship between the cursor’s position and the torque applied to the system was held constant even when the simulated mass was increased. Thus, any change in torque produced was neither due the subjects’ perception of the mass nor due to their perception of the cursor. The time at which the subjects torque changed direction was seen to be significantly different (p<0.005) during trials which the mass changed. This change in torque is concluded to be position-dependent. However the possibility of this being a merely mechanical effect could not be ruled out by due to poor EMG collection.

A post-hoc analysis of different position-dependent motor control models, was done. Particularly, an exponential spring model, a linear spring model, and a linear spring with relative damping model were each tested to see how well ...


Realization Of Dynamixel Servo Plant Parameters To Improve Admittance Control For A Compliant Human-Robot Interaction, Ahmad Zahid Rao Dec 2015

Realization Of Dynamixel Servo Plant Parameters To Improve Admittance Control For A Compliant Human-Robot Interaction, Ahmad Zahid Rao

Theses

In theory, admittance control offers a very effective method of implementing smooth human-robot interaction. It allows the user’s applied force to control the movement of a powerful robot as if the robot were a small, passive mass. However, the real-world application of admittance control faces limitation posed by the dynamics of servo motors, the accuracy of the force sensors, and the computation speed of processors.

This research investigates the limitations on achieving compliant passive behavior when using state-of-the-art actuators, sensors and processors. The work involves characterizing the dynamic behavior of the servo motors, development of improved differential equations representing ...


Comparison Of Muscle Synergies Elicited From Transcranial Meganetic Stimulation (Tms) And Voluntary Movements, Yifei Wei Dec 2015

Comparison Of Muscle Synergies Elicited From Transcranial Meganetic Stimulation (Tms) And Voluntary Movements, Yifei Wei

Theses

A key question in motor control is the redundancy of musculoskeletal elements involved. This problem refers to as the degree of freedom problem. The Muscle Synergy Hypothesis is one of the hypotheses that aim to resolve the problem which defines that a muscle synergy is a combination of a small set of muscles activated at different levels, serving as a building block that constructs motor behaviors. A recent study (Overduin et al. 2012) demonstrated that muscle synergies decomposed by Nonnegative Matrix Factorization (NMF) from EMG patterns evoked by intra-cortical microsimulation (ICMS) in the monkey remarkably matched ones observed in naturalistic ...


Differentiation Of Mouse Embryonic Stem Cells Into Insulin-Producing Cells: Optimization To Enhance The Overall Differentiation Efficiency, Xiaotang Ma May 2015

Differentiation Of Mouse Embryonic Stem Cells Into Insulin-Producing Cells: Optimization To Enhance The Overall Differentiation Efficiency, Xiaotang Ma

Theses

Embryonic stem cells have the potential to differentiate into multiple cell types including insulin-producing cells (IPCs), which is becoming one of the promising cell sources for treating type 1 diabetes mellitus. However, in order to achieve functional stem cell-derived cells, it is important to generate more mature IPCs and to keep long-term viability post differentiation process. In this study, we varied several factors including different embryonic body culture conditions, digested cells seeding density and various coatings required for differentiation to optimize a previously established protocol to enhance the overall differentiation efficiency. Moreover, a three-dimensional in vitro collagen tissue culture system ...


Tendon Reflex Protocol For Exploring The Mechanisms Associated With Whole Body Vibration, Ikechukwu Okeke May 2015

Tendon Reflex Protocol For Exploring The Mechanisms Associated With Whole Body Vibration, Ikechukwu Okeke

Theses

Whole body vibration (WBV) machines have in recent years been widely used as rehabilitation equipment. Whole body vibration has been shown to have positive effects on muscle response. Cerebral palsy (CP) is a neurodevelopmental condition that includes a group of non-progressive, but often changing, motor impairment syndromes arising in the early stages of human development. The aim of this project was to design a protocol and related instruments to assess the tendon reflex in response to WBV. Both a press pedal used for measuring the force exerted by the foot and a hammer used for measuring the stimulating force were ...


Behavior Of Deformed Dermal Fibroblasts Seeded On A Silicon Membrane Under High Levels Of Strain, Laura Osorno May 2015

Behavior Of Deformed Dermal Fibroblasts Seeded On A Silicon Membrane Under High Levels Of Strain, Laura Osorno

Theses

The main objective of this thesis is to understand, from a molecular perspective, the morphological and functional abnormalities of human dermal fibroblasts as a response to deformation produced by a normal force that can lead to the potential formation of stretch marks in pregnant women, adolescents, and people with Cushing's syndrome. The main function of dermal fibroblasts is to produce the essential fibrous components of the extracellular matrix (ECM) of the skin.

In order to study the mechanism of stretch mark formation, neonatal human dermal fibroblasts were seeded on a silicon membrane for controlled deformation. Upon reaching a confluence ...


Total Quality Management (Tqm) Of Clinical Engineering In New Zealand Public Hospitals, Sushil Pramod Varma Jan 2015

Total Quality Management (Tqm) Of Clinical Engineering In New Zealand Public Hospitals, Sushil Pramod Varma

Theses

In the modern world, medical technology plays a very significant role in the healthcare delivery system. However, technology can malfunction, and the manner in which it is used can create technology-induced hostility amongst patients. Unsafe equipment can be dangerous for operators as well as to the patients, and can cause incorrect diagnoses, injuries and even death in patients. This study provides valuable information on the management of biomedical equipment, service quality and internal customer satisfaction, and recommends the two most effective models for managing biomedical equipment in public hospitals.


Visualeyes 2020: A Software Suite To Integrate Instrumentation To Study The Near Triad Of Vergence, Stephen J. Lestrange Dec 2014

Visualeyes 2020: A Software Suite To Integrate Instrumentation To Study The Near Triad Of Vergence, Stephen J. Lestrange

Theses

A complete instrumentation suite has been constructed for use in a randomized clinical trial to be funded from the National Institute of Health and study the underlying potential mechanism(s) of vision therapy. This suite is designed to track rotation of each eye (vergence) as well as measure the lens power of the eye's lens (accommodation). The system is designed to dissect the near triad which is composed of the pupil constriction, vergence and accommodation. The visual targets are programmed to be shown on two sets of computer screens which allowed vergence, accommodation and proximal vergence cues to be ...


Fem Of Electrospinning Compared To Inkjet Printing Model, Maikel Ghaly Dec 2014

Fem Of Electrospinning Compared To Inkjet Printing Model, Maikel Ghaly

Theses

Electrospinning is a process that uses electrostatic forces to produce nanofibers, or fibers in the nano scale. Nanofibers are widely used in many fields like drug delivery and tissue engineering. Nowadays, it is gaining much attention in the research community as an advantageous process. However, there are many parameters that controlnanofiber formation. This research intends to develop a model of electrospinning on the basis of an inkjet printer technique by using a computer aided simulation (COMSOL). Inkjet printing is a technique that delivers small volumes at high repetitions which can betransported by electrostatic forces through the air onto their intended ...


An Electrospinning Apparatus For The Production Of Heterogeneous Scaffolds And Their Application In Cartilage Regeneration, Andrew Ryan Hollingsworth Dec 2014

An Electrospinning Apparatus For The Production Of Heterogeneous Scaffolds And Their Application In Cartilage Regeneration, Andrew Ryan Hollingsworth

Theses

The human body contains a vast array of soft and hard tissues, each with their own unique set of physical, chemical, mechanical, and electrical properties. It is the combination of these tissues that allows the human body to function as it does. However, these tissues are subject to wear, fatigue, and injury and thus can potentially limit the functions of the body. Therefore, tissue engineering has sought various natural and synthetic materials that can be used for fabrication of cellular scaffolds that have the ability to promote cellular attachment, proliferation, differentiation, and eventual whole tissue formation for replacement and repair ...


Evaluation Of Methods To Account For Release From Nanofiber Scaffolds, Jennifer Moy May 2014

Evaluation Of Methods To Account For Release From Nanofiber Scaffolds, Jennifer Moy

Theses

Electrospinning is a common technique utilized to form fibers from the micro- to nanometer range. Nanofibers form through electrospinning can be utilized as scaffolds since the fiber structures are similar to the structures within the extracellular matrix. Researchers use additives, such as growth factors, to help facilitate cell proliferation and function. Also, researchers are attempting to use electrospun fibers for drug delivery and as wound dressings since the electrospun fibers have high surface area to volume ratio. In both situations, the release of either the additive or the drug needs to be controlled so that the fibers would release the ...