Fmri Assessment Of Ischemic Stroke In Humans, 2012 New Jersey Institute of Technology
Fmri Assessment Of Ischemic Stroke In Humans, Rui Yuan
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 ...
Testing The Efficiency Of Vertically Aligned Gold Nanowires On A Titanium Needle Implantable Neural Electrodes In The Rattus Norvegicus Hippocampus, 2012 University of Arkansas, Fayetteville
Testing The Efficiency Of Vertically Aligned Gold Nanowires On A Titanium Needle Implantable Neural Electrodes In The Rattus Norvegicus Hippocampus, Lauren Kegley
Electrical Engineering Undergraduate Honors Theses
Miniaturized multi-electrode arrays are MEMS devices that have found use as neural prosthetics (Neuro-MEMS). As implants they can interface with neurons as sensors or actuators and help compensate for loss of sensory input, motor control, or cognitive function. The micro-electrodes, studied here, were developed in-house. They have a vertically aligned gold nanowire array and are mounted on a sturdy fine gauge titanium needle. Hence, the bill of materials and design characteristics encourage its use as neural probe. For this study, a probe was tested in vivo for signal acquisition in the hippocampus of a Rattus Norvegicus (Sprague Dawley Rat). Using ...
Novel Phantoms And Post-Processing For Diffusion Spectrum Imaging, 2012 The University of Texas Graduate School of Biomedical Sciences at Houston
Novel Phantoms And Post-Processing For Diffusion Spectrum Imaging, Vaibhav Juneja
UT GSBS Dissertations and Theses (Open Access)
High Angular Resolution Diffusion Imaging (HARDI) techniques, including Diffusion Spectrum Imaging (DSI), have been proposed to resolve crossing and other complex fiber architecture in the human brain white matter. In these methods, directional information of diffusion is inferred from the peaks in the orientation distribution function (ODF). Extensive studies using histology on macaque brain, cat cerebellum, rat hippocampus and optic tracts, and bovine tongue are qualitatively in agreement with the DSI-derived ODFs and tractography. However, there are only two studies in the literature which validated the DSI results using physical phantoms and both these studies were not performed on a ...
Electrical & Magnetic Stimulation And Health, 2012 University of Nevada, Las Vegas
Electrical & Magnetic Stimulation And Health, Yiyan Li
College of Engineering: Graduate Celebration
1, Introduction Most of the patients with neural diseases such as Parkinson’s disease, Stroke and Depression, cannot be cured by taking pills or conducting surgery. In contrast to the conventional therapies, physical therapies such as TMS (transcranial magnetic stimulation) (Fig. 1) and tDCS (transcranial direct current stimulation) (Fig. 2) are the most popular methods in treating neural disorders with a non-invasive way. TMS employs electromagnetic (1-3 Tesla) induction generates an Electric field suitable for neural stimulation; tDCS employs a weak current (1-2 mA) to modulate neuronal excitabilities.
Functional Electrical Stimulation In Spinal Cord Injury Rehabilitation, 2012 Touro College
Functional Electrical Stimulation In Spinal Cord Injury Rehabilitation, Meir Hildeshaim
The Science Journal of the Lander College of Arts and Sciences
The following is an excerpt from the introduction to this article: Spinal cord injury is defined as a “disconnection syndrome” that results in a loss of ability of the spinal cord to communicate ascending and/or descending impulses (Hamid and Hayak 2008). Due to its role as the primary conduit of motor and sensory impulses, spinal cord injury is widely regarded as one of the most catastrophic, survivable injuries a person can suffer. Depending on the severity and placement of the injury, the patient can experience a wide range of disability or death. A mild injury may result in the ...
Effect Of Extracellular Matrix (Ecm) Protein Micropatterns On The Behavior Of Human Neuroblastoma Cells, 2011 University of Nebraska-Lincoln
Effect Of Extracellular Matrix (Ecm) Protein Micropatterns On The Behavior Of Human Neuroblastoma Cells, Ishwari Poudel
Engineering Mechanics Dissertations & Theses
Recent advances in patterning techniques and emerging surface microtechnologies have allowed cell micropatterning to control spatial location of the cells on a surface as well as cell shape, attachment area, and number of contacting neighbor cells. These parameters play important roles in cell cellular behaviors. Cell micropatterning has thus become one of the most important strategies for biomedical applications, such as, tissue engineering, diagnostic immunoassays, lab-on-chip devices, bio-sensing, etc., and cell biology studies as well. For neuronal cells, there have been attempts to distribute neuronal cells on specific patterns to control cell-to-cell interaction. However, there have been very limited understanding ...
Implementation Of Medicinal Leech Preparation To Investigate The Connection Between The Motor Neuron And Muscle Fiber Via Sharp Electrode Electrophysiology, 2011 California Polytechnic State University - San Luis Obispo
Implementation Of Medicinal Leech Preparation To Investigate The Connection Between The Motor Neuron And Muscle Fiber Via Sharp Electrode Electrophysiology, Chandra Nikole Miller
Master's Theses and Project Reports
There are forty registered organophosphates in the United States and they range from pesticides and insecticides to nerve agents or neurotoxins such as sarin. Organophosphates (OP’s) have been used in chemical warfare for years and tend to lead to death due to an attack on the nervous system. Chemical assays and mass microscopy have been used to assess the concentration of OP’s in the environment, but both methods require the body to metabolize the OP first, which can be detrimental to the victim. It is crucial to come up with a method to investigate and detect these neurotoxins ...
Equivalent Circuit Implementation Of Demyelinated Human Neuron In Spice, 2011 California Polytechnic State University - San Luis Obispo
Equivalent Circuit Implementation Of Demyelinated Human Neuron In Spice, Nathan A. Angel
Master's Theses and Project Reports
This work focuses on modeling a demyelinated Hodgkin and Huxley (HH) neuron with Simulated Program with Integrated Circuit Emphasis (SPICE) platform. Demyelinating disorders affect over 350,000 people in the U.S and understanding the demyelination process at the cellular level is necessary to find safe ways to treat the diseases . Utilizing a previous SPICE model of an electrically small cell neuron developed by Szlavik , an extended core conductor myelinated neuron was produced in this work. The myelinated neuron developed has seven active Nodes of Ranvier (nodes) separated by a myelin sheath. The myelin sheath can be successfully ...
Characterizing Nerve Fiber Activation By Varying Fiber Diameter And Depth Within A Conductive Medium: A Finite Element Approach, 2011 California Polytechnic State University - San Luis Obispo
Characterizing Nerve Fiber Activation By Varying Fiber Diameter And Depth Within A Conductive Medium: A Finite Element Approach, Nathan Daniel Soto
Master's Theses and Project Reports
In some instances neuropathies can be diagnosed through a conduction velocity test. However, not all neuropathies can be classified using this method. Gaining an understanding of how the stimulus level varies for different fiber sizes at different fiber depths within a conductive medium will provide useful information for simulation studies.
Following a two-step approach using COMSOL and MATLAB, a simulation was implemented to investigate the stimulus necessary to activate different sized fibers at different depths. In this two-step approach, COMSOL was used to describe the voltage profile that would be present within a conductive medium after a stimulus was applied ...
Evaluation Of Delivery Conditions For Cutaneous Plasmid Electrotransfer Using A Multielectrode Array, 2011 Old Dominion University
Evaluation Of Delivery Conditions For Cutaneous Plasmid Electrotransfer Using A Multielectrode Array, Bernadette Ferraro, Loree C. Heller, Yolmari L. Cruz, Siqi Guo, Amy Donate, Richard Heller
Electroporation (EP) is a simple in vivo method to deliver normally impermeable molecules, such as plasmid DNA, to a variety of tissues. Delivery of plasmid DNA by EP to a large surface area is not practical because the distance between the electrode pairs, and therefore the applied voltage, must be increased to effectively permeabilize the cell membrane. The design of the multielectrode array (MEA) incorporates multiple electrode pairs at a fixed distance to allow for delivery of plasmid DNA to the skin, potentially reducing the sensation associated with in vivo EP. In this report, we evaluate the effects of field ...
Investigation Of A Simulated Annealing Cooling Schedule Used To Optimize The Estimation Of The Fiber Diameter Distribution In A Peripheral Nerve Trunk, 2011 California Polytechnic State University - San Luis Obispo
Investigation Of A Simulated Annealing Cooling Schedule Used To Optimize The Estimation Of The Fiber Diameter Distribution In A Peripheral Nerve Trunk, Arya Vigeh
Master's Theses and Project Reports
In previous studies it was determined that the fiber diameter distribution in a peripheral nerve could be estimated by a simulation technique known as group delay. These results could be further improved using a combinatorial optimization algorithm called simulated annealing. This paper explores the structure and behavior of simulated annealing for the application of optimizing the group delay estimated fiber diameter distribution. Specifically, a set of parameters known as the cooling schedule is investigated to determine its effectiveness in the optimization process.
Simulated annealing is a technique for finding the global minimum (or maximum) of a cost function which may ...
Novel Bioelectrical Measurement Using A Digital Biopotential Monode, 2011 Dublin Institute of Technology
Novel Bioelectrical Measurement Using A Digital Biopotential Monode, Mark Nolan, Edward Burke, Eugene Coyle
In conventional biopotential recording, two or more electrodes are placed on the body. A unipolar lead records the time-varying electrical potential at a single point (relative to a reference potential) via one signal electrode. A bipolar lead records the time-varying potential difference between two points via two signal electrodes. In each case, the signal electrodes are connected to high impedance amplifier inputs, while an additional electrode provides a low-impedance path between the amplifier and human subject. Bipolar leads are usually preferred since interference appearing at both signal electrodes can be eliminated using an instrumentation amplifier with high CMRR. A drawback ...
Electro-Gene Transfer To Skin Using A Noninvasive Multielectrode Array, 2011 Old Dominion University
Electro-Gene Transfer To Skin Using A Noninvasive Multielectrode Array, Siqi Guo, Amy Donate, Gaurav Basu, Cathryn Lundberg, Loree Heller, Richard Heller
Because of its large surface area and easy access for both delivery and monitoring, the skin is an attractive target for gene therapy for cutaneous diseases, vaccinations and several metabolic disorders. The critical factors for DNA delivery to the skin by electroporation (EP) are effective expression levels and minimal or no tissue damage. Here, we evaluated the non-invasive multielectrode array (MEA) for gene electrotransfer. For these studies we utilized a guinea pig model, which has been shown to have a similar thickness and structure to human skin. Our results demonstrate significantly increased gene expression 2 to 3 logs above injection ...
Simulation Studies Of Pulsed Voltage Effects On Cells, 2010 Old Dominion University
Simulation Studies Of Pulsed Voltage Effects On Cells, Jiahui Song
Electrical & Computer Engineering Theses & Disssertations
This dissertation research focuses on the new field of pulsed electric field interactions with biological cells. In particular, "Intracellular Electromanipulation" which has important biomedical applications, is probed. Among the various aspects studied, nanosecond, high-intensity pulse induced electroporation is one phenomena. It is simulated based on a coupled scheme involving the current continuity and Smoluchowski equations. A dynamic pore model can be achieved by including a dependence on the pore population density and a variable membrane tension. These changes make the pore formation energy E(r) self-adjusting and dynamic in response to pore formation. Additionally, molecular dynamics (MD) simulations are also ...
Evaluating The Use Of Engineered Nervous Tissue Constructs In The Repair Of Peripheral Nerve Lesions And Amputations, 2010 University of Pennsylvania
Evaluating The Use Of Engineered Nervous Tissue Constructs In The Repair Of Peripheral Nerve Lesions And Amputations, Niranjan Kameswaran
Publicly Accessible Penn Dissertations
Severe trauma to the limbs can often result in the lesioning, or even amputation, of the underlying peripheral nerves. In these cases, endogenous neural repair mechanisms are compromised and a path to the end target may be lost, resulting in the need for surgical intervention. Current repair strategies are incapable of maintaining this regenerative pathway, or providing a bridge to a surrogate end target, often resulting in incomplete repair.
This thesis describes the development and evaluation of a novel method of addressing peripheral nerve lesions and amputations that utilizes living tissue-engineered neural grafts. These grafts are created by the controlled ...
Developing Chitosan-Based Biomaterials For Brain Repair And Neuroprosthetics, 2010 Department of Materials Science and Engineering, UTK
Developing Chitosan-Based Biomaterials For Brain Repair And Neuroprosthetics, Zheng Cao
Chitosan is widely investigated for biomedical applications due to its excellent properties, such as biocompatibility, biodegradability, bioadhesivity, antibacterial, etc. In the field of neural engineering, it has been extensively studied in forms of film and hydrogel, and has been used as scaffolds for nerve regeneration in the peripheral nervous system and spinal cord. One of the main issues in neural engineering is the incapability of neuron to attach on biomaterials. The present study, from a new aspect, aims to take advantage of the bio-adhesive property of chitosan to develop chitosan-based materials for neural engineering, specifically in the fields of brain ...
Electrically Mediated Delivery Of Plasmid Dna To The Skin, Using A Multielectrode Array, 2010 Old Dominion University
Electrically Mediated Delivery Of Plasmid Dna To The Skin, Using A Multielectrode Array, Richard Heller, Yolmari Criz, Loree C. Heller, Richard A. Gilbert, Mark J. Jaroszeski
The easy accessibility of skin makes it an excellent target for gene transfer protocols. To take full advantage of skin as a target for gene transfer, it is important to establish an efficient and reproducible delivery system. Electroporation is a strong candidate to meet this delivery criterion. Electroporation of the skin is a simple, direct, in vivo method to deliver genes for therapy. Previously, delivery to the skin was performed by means of applicators with relatively large distances between electrodes, resulting in significant muscle stimulation and pain. These applicators also had limitations in controlling the directionality of the applied field ...
In-Vivo Testing Of Vertically Aligned Nanowire Implantable Titanium Electrodes In The Rattus Norvegicus Hippocampus, 2010 University of Arkansas, Fayetteville
In-Vivo Testing Of Vertically Aligned Nanowire Implantable Titanium Electrodes In The Rattus Norvegicus Hippocampus, Lauren Kegley
Inquiry: The University of Arkansas Undergraduate Research Journal
Miniaturized multielectrode arrays are MEMS devices that have found use as neural prosthetics (Neuro-MEMS). As implants, they can interface with neurons as sensors or actuators and help compensate for loss of sensory input, motor control, or cognitive functions. The microelectrodes studied here were developed in-house. They have a vertically aligned gold nanowire array and are mounted on a sturdy titanium needle with a fine gauge. Hence, the bill of materials and design characteristics encourage their use as a neural probe. For this study, a probe was tested in vivo for signal acquisition in the hippocampus of a Rattus Norvegicus (Sprague ...
Electroporation-Mediated Delivery Of A Naked Dna Plasmid Expressing Vegf To The Porcine Heart Enhances Protein Expression, W. G. Marshall Jr., B. A. Boone, J. D. Burgos, S. I. Gografe, M. K. Baldwin, M. L. Danielson, M. J. Larson, D. R. Caretto, Y. Cruz, B. Ferraro, L. C. Heller, K. E. Ugen, M. J. Jaroszeski, R. Heller
Gene therapy is an attractive method for the treatment of cardiovascular disease. However, using current strategies, induction of gene expression at therapeutic levels is often inefficient. In this study, we show a novel electroporation (EP) method to enhance the delivery of a plasmid expressing an angiogenic growth factor (vascular endothelial growth factor, VEGF), which is a molecule previously documented to stimulate revascularization in coronary artery disease. DNA expression plasmids were delivered in vivo to the porcine heart with or without coadministered EP to determine the potential effect of electrically mediated delivery. The results showed that plasmid delivery through EP significantly ...