Biomedical Engineering and Bioengineering Commons^™

Diffuse Axonal Injury Effect On Myelinating Cells And Axons, Jennifer Alison Zalk

Theses

There is no supporting evidence whether myelin degeneration in diffuse axonal injury (DAI) of the white matter is due to death of myelinating oligodendrocytes or secondary axotomy. Cortical neurons are not able to remain healthy in culture to have their axons myelinated. Dorsal root ganglion (DRG) neurons have been shown to be myelinated by cortical oligodendrocytes in culture. An in vitro stretch injury model was used to analyze the DRG axon pathology during and after injury. DRG myelinating Schwann cells are analyzed to demonstrate what is expected from injury to oligodendrocytes. DRG axons demonstrated a high tolerance to stretch …

Quantification Of Human Motion On Roller Coaster Rides, Chirag Burman

Theses

Case reports have been published of people experiencing symptoms of traumatic brain injury (TBI) and/or ailments of the vascular tissue around the head. These reports pointed towards G-forces, a scalar measure without a specified direction, which represent the measure of the acceleration of an object divided by acceleration caused by gravity (9.81 m/s²), as a cause of said injuries. Research has been conducted on quantifying the G-forces experienced while on roller coasters, as well as the change in heart rate. However these studies have not been able to show a link between roller-coasters and symptoms.

This thesis aims …

Fuzzy Logic For Task Space Telemanipulation Of A Five Fingered Robotic Hand, Raaghavann Srinivasan

Theses

This work presents a fuzzy logic based HandyMan (Hand gesture commands for grasping and manipulation) system to recognize the operator's hand gestures during task space telemanipulation. A combination of joint positions may be shared between at least two manipulation gestures. To avoid misinterpretation of gestures by the gesture recognition system, six new manipulation gestures were introduced. The gestures are produced by the user wearing a CyberGlove™.

This system replaces the previous HandyMan gesture recognition method. The output of the fuzzy system drives the state machines to implement the gestures with the robot hand.

The experimental results show that the proposed …

Experimental Evaluation Of Near Infrared Light Penetration Into Neural Tissue, Ujwal Anil Parikh

Theses

Near infrared (NIR) lasers find applications in medicine both for diagnostic and treatment purposes. Penetration depth into the tissue is a critical parameter to be considered in these NIR laser applications. Published data on the optical properties of rodent neural tissue are rare, despite the frequent use of rats as animal models. The aim of this study was to directly measure the light intensity profile inside the rat brain gray matter that is illuminated by an NIR laser beam. The local light intensities were sampled using an optical fiber inserted into the brain. The intensity profile in the axial direction …

Analysis Of Tissue Engineering Strategies For Bone-Related Applications, Timothy Buirkle

Theses

Over the past few decades, tissue engineering approaches have pushed their way to the forefront of biotechnological research and development, serving a wide variety of applications. This research utilizes quantitative methods to analyze the outcome of two bone tissue engineering studies. In an in vivo study, the use of Negative Pressure Wound Therapy (NPWT) in combination with stem cell-loaded scaffolds was investigated for the repair of large bone defects. Quantitative histological analysis was performed by determining both the percentage of cells proliferating (BrdU), as well as cells expressing bone-specific markers of alkaline phosphatase (A L P) in the defect. Total …

Quantifying Prehension In Persons With Stroke Post Rehabilitation, Saumya Sara Puthenveettil

Theses

This study describes the analysis of reaching and grasping abilities of the hemiparetic arm and hand of patients post stroke after a series of interactive virtual reality (VR) simulated training sessions and conventional physical therapy of similar intensity. Six subjects participated in VR training and five subjects in clinical rehabilitation for two weeks. Subjects’ finger joint angles were measured during a kinematic reach to grasp test using CyberGlove® and arm joint angles were measured using the trackSTARTM system prior to training and after training. Downward force applied to the object during grasping was assessed using Nano17TM, a force/torque sensor system …

Alterations In Brain Connectivity After Spinal Cord Injury Using Functional Mri, Yamin Ahmed Noor

Theses

Every year, approximately 50 people per million of inhabitants are inflicted by Spinal Cord Injury (SCI). The long-term impairment of the SCI patients has led researchers to investigate different rehabilitation and treatment efforts that require careful observations to be made on reliable markers. Presently, a number of neuropsychological assessments are used for SCI rehabilitation and research purposes. However, there is a need for the discovery of sensitive biomarkers that can be used to characterize SCI. Altered functional connectivity in the brain has been observed in a number of neurological patient populations. Hence, it was hypothesized that such alterations in brain …

Fmri Assessment Of Ischemic Stroke In Humans, Rui Yuan

Theses

Cerebral ischemia, or brain ischemia is a kind of stroke where the blood flow is insufficient to the metabolic demand of brain. The lack of oxygen supply will directly lead to the death of brain tissue. There are two major injury regions: the infarct and penumbra. Mostly, since the infarct regions became dead tissues rapidly after stroke, there is a tiny possibility to rescue them in time. But penumbra parts are different. Tissues there will be viable for hours after ischemia. Hence, both theoretically and practically, it is possible to salvage those cells in the penumbra region. Diffusion weighted image …

Soy Protein-Poly (L-Lactic Acid) Blend Nanofibers For Drug Delivery Of Nardostachys Jatamansi, Swetha Tiwari

Theses

Electrospun nanofibers when nanofi bers are impregnated with drugs play a significant role in drug delivery. Nanomedical approaches to drug delivery focus on developing nanoscale particles or molecules to improve the bioavailab ility of a drug.

Biodegradable nanofibers were developed using Poly (L – lactic acid) and Soy protein for the delivery of an ayurvedic drug, Nardostachys jatamansi. A weighed quantity of powdered drug – Nardostachys Jatamansi was subjected to Soxhlet extraction using water and ethanol in equal quantities. Various blends of the drug extract and soy protein solution are prepared and mixed in Poly (L-lactic acid). Nanofibers of …

Neuralsta: A Software Tool For Neural Stimulation And Recording Applications With A Laser Control, Rimi Sahu

Theses

The subject of this thesis is a software tool created in Matlab ® for neural stimulation and recording of the evoked potentials. The stimulation output can be delivered in electrical units for immediate use for neural stimulation or as a power control signal to a laser. NeuralSTA is designed to generate arbitrary waveforms of stimulation and simultaneously record the neural response while implementing the spike triggered averaging (STA) method, hence the name NeuralSTA. The output (stimulation) signal can be created in monophasic, biphasic or inverted monophasic forms (for laser control applications). Controls for pulse modulation allow shaping of the pulse …

Theoretical Prediction Of Joint Reaction Force In A Dynamic General 3-D Pendulum Tree Model For Human Or Animal Motion, Sucheta Goyal

Theses

Lagrangian dynamics and the method of superfluous coordinates are applied to predict dynamic joint reaction forces in an idealized flexible model of a branched 3-D pendulum tree system. The number of segments and joints on the tree are adjustable as is the branching tree pattern. The segments that comprise the tree are assumed to be one- dimensional rigid rods containing a discrete set of mass points that is both flexible in number and distribution on the tree. The idealized 3-D pendulum tree system is intended to provide a flexible theoretical framework to model and better understand the dynamics of human …

Neural Differentiation Of Pluripotent Stem Cells And Applications To Micropatterned Agarose Hydrogel For Nerve Guidance, Jamila S. Gittens

Theses

Many central nervous system (CNS) disorders are attributable to damaged oligodendrocytes, the cells that form the myelin sheath of axons. An effective source of human oligodendrocytes is crucial, making pluripotent stem cells, such as embryonic stem (ES) cells, an attractive source for nerve tissue repair and regeneration due to their unlimited capacity for self-renewal and their ability to differentiate into all major cell lineages. Bioengineered 3-D hydrogel culture systems have the potential to elucidate mechanisms required for regeneration of CNS cells. The goals of this study are: (1) to investigate the effects of retinoic acid (RA), sonic hedgehog (shh) agonist, …

Development Of 3-D Liver Model For Drug Screening Applications, Divya Rajendran

Theses

The need for a an in vitro drug screening system that mimics the structural organization of natural liver for multi-functionality and maintenance of hepatocytes has become vital in the drug development process. The objective of this study was to engineer a three-dimensional (3-D) liver model using chitosan-based nanofiber scaffolds and co-culture system (adult rat hepatocytes and 3T3-J2 fibroblasts) to mimic the natural liver and to justify its application for in vitro drug screening. Chitosan nanofiber scaffolds were fabricated by electrospinning technique. In order to promote cell adhesion on the chitosan scaffolds, the scaffolds were coated with a cell adhesion molecule, …

Temperature Elevations Due To Nir Exposure In The Brain Tissue, Ali Ersen

Theses

Near infrared (NIR) lasers have been used in medical applications both for diagnostic and therapeutic purposes. Temperature elevation profile inside the tissue is a critical factor that needs to be better understood in these applications. The purpose of this study is to determine the temperature distribution due to a low power N I R laser irradiation in living neural tissue. Temperature measurements were made directly using a thermocouple probe inside the rat brain cortex within the sagittal plane. The spatial map indicates that N I R light penetrates more readily in the vertical directions than the spreading in the horizontal …

Alendronate Treatment Elicits A Reduction In Fatigue-Life Of Canine Cortical Bone, Joseph Ryan Geissler

Theses

Bone serves contradictory needs; bone must be strong yet light, and stiff yet flexible. At the tissue level bone material withstands cyclic loading without failing by dissipating energy via the formation and accumulation of microdamage. Proper removal of this damage in exchange for fresh tissue is vital to bone maintenance, and is achieved through a remodeling process. Imbalanced remodeling leads to osteoporotic fractures. Bisphosphonate drugs are proven to reduce fracture risk. However, the long-term effects of bisphosphonates on tissue-level properties are unknown. This study characterized the fatigue-life of cortical bone tissue after bisphosphonate treatment with alendronate (Aln). 1 1th ribs …

Influence Of Rear Wheel Tire Type On Wheelchair Propulsion Biomechanics, Mathew Yarossi

Theses

The objective of this study was to determine how rear wheel tire type affects wheelchair propulsion mechanics. Four persons with paraplegia and four persons with tetraplegia propelled their own wheelchairs on a roller system at self-selected speed using five different pairs of tires. Upper limb and trunk kinematics, perceived exertion, stroke pattern and the temporal characteristics of propulsion were measured. When using pneumatic (air filled) tires, with lower rolling resistance, participants had lower push frequency (p < .05), higher self selected speed (p < .05), less perceived exertion, less shoulder internal rotation, and a longer push stroke than when using solid, high rolling resistance tires. As rolling resistance increased, participants experienced negative changes in propulsion characteristic that contradicted current clinical practice guidelines for upper limb preservation following spinal cord injury. In addition, kinematics with solid, high rolling resistance tires were similar to those described during uphill or over carpet propulsion. In order to avoid unnecessary strain on the upper limbs and unwanted changes in propulsion biomechanics, wheelchair users, clinicians, and researchers should consider the use of lower rolling resistance, pneumatic rear tires.

Use Of Fluorescent Micropsheres To Measure Coronary Flow Reserve In Rat Animal Model, Riddhi Harsh Shah

Theses

Heart attacks result from reduced or blocked blood flow through major coronary arteries, resulting in permanent damage to heart muscle. Coronary blood flow (CBF) is thus important to measure in experimental animal models of heart disease. A standard method to measure CBF uses tracer microspheres (Ø = 15 µm) injected into the left ventricle that flow through coronary arteries but cannot pass through capillaries and so become trapped in heart muscle. Previously, radioactive or colored microspheres have quantified the number of tracers trapped in the muscle. Fluorescent microspheres offer a more recent and more sensitive measurement mode. However, fluorescent microspheres …

A Microfluidic Culture For Two Populations Of Dorsal Root Ganglia For Differential Staining, Ishnoor Sidhu

Theses

The goal of this study was to design and fabricate a microfluidic system that can be used to visibly distinguish the two populations of dorsal root ganglia (DRGs) by differential staining. Polydimethylsiloxane (PDMS) is the most widely used silicon-based organic polymer, and is particularly known for its wide spread use in microfluidics. Various methods have been employed to pump fluids in these channels for applications ranging from patterning of cells and biomolecules to control of local environment factors such as temperature, which requires external pumping or other applied forces. We demonstrated a pump-free device that exploits the surface energy stored …

The Effect Of Dynamic Standing On The Bone Mineral Density Of Non-Ambulatory Children: A Pilot Study, Megan Diane Damcott

Theses

In recent decades, research in osteoporosis has expanded to include the effects of prolonged immobilization on the load-bearing bones of non-ambulatory children. One current therapeutic intervention for this population is a passive standing program, in which the body is fully supported and continuous, stationary loading is applied to the bones, leading to the legs being primarily inactive. This research focused upon the effect of passive standing and a new therapeutic intervention of dynamic standing, a standing therapy in which the body is supported but vertical, reciprocal displacements which mimic the walking gait are applied to the feet, causing the muscles …

Tilt Simulation : Virtual Reality Based Upper Extremity Stroke Rehabilitation, Harish Damodaran

Theses

The primary objective of this research is to design a recreational rehabilitation videogame that interactively encourages purposeful upper extremity gross motor movements. The simulation is also capable of continuous game modification to fit changing therapy goals, to match the needs of the players, and to provide continued motivation while capturing the interactive repetition. This thesis explains the design and features of this latest simulation - Tilt. Tilt uses physics to develop an engaging training experience and provides a realistic approach to virtual reality simulation including friction, elasticity and collisions between objects. It is designed to train upper extremity function as …

Motor Planning For Reach Memorization Task In 3d Space, Atul Narkhede

Theses

Arm reaching towards remembered targets in three-dimensional space was analyzed. The aim of the project was to test whether various amounts of visual feedback, in combination with constant forces applied to the arm during reaching would affect the magnitude and direction of the reaching errors. The robotic arm (Haptic Master, Moog Inc) recorded the spatial position of the pointer attached to its end effector, thus tracking the movement of the subject's arm. Three haptically rendered targets at different points in space were presented to the subjects using stereo virtual environment. The simulation was programmed using Visual C++ and OpenGL. Eight …

Non-Invasive Interventions Top Reduce Low Back Dysfunction, Nadi Atalla

Theses

This study aims to quantitatively evaluate the low back condition so that low back dysfunction can be identified and classified when measurements show a variance from the normal. The evaluation is done by using the hysteresis concept. In this study, subjects received two different types of treatment: massaging using a mechanical massager for ten minutes and manual massaging by a professional physician. Using the Automated Anatomic Torsion Monitor (A-ATM), the low back of the subject was evaluated before and after treatment. The change in Hysteresis Loop Area (HLA) was -12.5% for mechanical massaging and -15.7% for manual massaging. The negative …

Development Of A Centrifugal Microfluidic Device For Separation And Sorting In Biological Fluids, Gaurav Sunil Bagwe

Theses

A wide interest in employing micron-scale, integrated biochemical analysis systems for economical and rapid diagnosis has been the principal motivation behind this project. Low operating costs, portability and fast diagnosis times make centrifugal microfluidic devices an attractive option in patient-side diagnostics. Some essential tasks to be performed in microfluidic devices are sample-reagent transport, mixing, separation and detection. All these tasks require precise control of the RPM and spinning time. Centrifugal micro-fluidic platforms have been successfully implemented for detection of hepatitis A, tetanus, as well as for measurement of haemoglobin and hematocrit, for DNA analysis, and for assessment of cardiac disease …

Emg-Based Determination Of Upper Extremity Virtual Trajectory, Akshata Anand Korgaonkar

Theses

Movement and position of the limbs of the human body are controlled by the interaction between the muscle and the peripheral and central nervous system. This interaction is nothing but the neural signals. Neural signals are electrical in nature and referred as action potentials. An EMG is a summation of action potentials from the muscle fibers under the electrode placed on the skin. Thus it is easy to estimate the nature and timing of the movement from the firing of an EMG signal. Kai Chen in his dissertation has built the model to represent the arm movement with stiffness, damping, …

Effects Of Hypertension And Aging On Vascular Smooth Muscle Cell Contribution To Reconstituted Aortic Tissue Stiffness, Nancy Lisa Sehgel

Theses

Aortic stiffness increases with hypertension and aging, and much of this increase has been thought to occur due to changes in the extracellular matrix. However, an increase in cell stiffness could also be important. To study the cellular contribution to aortic stiffness, a reconstituted aortic tissue model (composed of vascular smooth muscle cells (VSMCs) in a collagen matrix) was developed. VSMCs isolated from thoracic aortic samples of 5-week and 18-week old male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats were passaged four times and then separately incubated in collagen for two days on a cylindrical mandrel. The resulting …

Creep Behaviour Of Hand Laminated Glass Reinforced Polymer Composites., Brian Quinn

Theses

The creep behaviour of hand laminated, glass fiber reinforced polyester composites were studied at coupon level, due to the use of similar materials in long term load bearing civil and structural engineering applications. Creep predictions were made by fitting the parameters of several viscoelastic models to experimental creep data as well as two accelerated test methods, time temperature superposition (TTS) and frequency time transformations (FTT). TTS experiments were carried out in a dynamic mechanical analyzer (DMA) in three point bending mode for three types of material systems. Creep compliance master curves representing the linear viscoelastic creep response at reference temperatures …

Composition-Structure-Property Relationships For Experimental Composite Nerve Guidance Conduits, Xiaofang Zhang

Theses

Many Nerve Guidance Conduits (NGCs) have been approved by the Food and Drug Administration (FDA) as an alternative to nerve autografting for guiding peripheral nerve regeneration. However these materials offer little therapeutic potential for favourable axon growth environment, and difficulty in balancing the mechanical properties and the degradation rate of the implanted material is also a contemporary challenge. This project involved the design of experimental composite NGCs comprising glass particles and Pluronic FI27 in the copolymer (poly(lactic-co-glycolic acid)) and examined the composition-structure-property relationships for such materials. Three glasses (0.5Si-(x) Na-0.2Ca-0.13Zn-(0.17-x) Ce) (0.0.04 > x > 0.14) were produced. Glasses were characterised using …

Neurorehabilitation Of The Hand Using The Cybergrasp[Tm] And Mirror Image, Amy Frances Boos

Theses

In recent years, researchers have explored the use of a mirror image as a means of rehabilitation for individuals suffering from hemiparesis. Through neuroimaging and functional testing, neurological improvement has been demonstrated in those that engage in mirror therapy. Bilateral training, or simultaneous movement of both sides of the body, has also been studied as a treatment method to improve function after cerebral vascular accident. The development of robotic systems to assist movement of the human body has played a major role in the fabrication of bilateral training devices.

In this experiment, the CyberGrasp™ robotic exoskeleton was used to assist …

A Haptic Control System For Functional Electrical Stimulation Of Paraplegic Legs, Mark R. Shaker

Theses

Functional electrical stimulation (FES) is a means by which paraplegic men and women can use their natural legs for walking. In FES the impaired muscles are stimulated with electricity in a proper cycle to cause the legs to move in a walking pattern. It can be greatly beneficial for paraplegics however, current systems are not widely used because they are difficult to control in a useful manner.

The system proposed here uses a haptic interface, one that utilizes the sense of touch, attached to a user’s index and middle fingers. The haptic device allows the wearer to feel with the …

Motor Data Scaling By Respiration Frequencies In Rest, Amit Madhukar Kamble

Theses

Functional Magnetic Resonance Imaging (fMRI) is widely used as a tool to see activations in the different brain regions. Motor data acquired from fMRI scan is accompanied with signal due to hemodynamic changes taking place during the scan. This hemodynamic signal is dominated by parameter alteration in the large vessels of brain. Scaling of task induced BOLD signal with hypercapnic or breathold data is one of the effective methods to minimize the signal due to large vessels. Patient discomfort and compliance has been a major issue with these methods hence in this study we used respiration frequencies in rest data …