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Bioelectrical and Neuroengineering

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Full-Text Articles in Biomedical Engineering and Bioengineering

Investigation Of The Electrode Polarization Effect For Biosensor Applications, Anil Koklu Aug 2019

Investigation Of The Electrode Polarization Effect For Biosensor Applications, Anil Koklu

Mechanical Engineering Research Theses and Dissertations

My research focuses on electrokinetic transport. Particularly, in this dissertation, we focus on fabrication and testing of micro electrodes with nanostructured surfaces to minimize the electrode polarization (EP) effects for biosensor applications. In the first study, electrochemical deposition of gold nanoparticles on to planar gold electrodes was used to generate rough surfaces. Dendritic nanostructures that reduced EP up to two orders of magnitude was obtained by optimizing the deposition conditions. These structures also enhanced dielectrophoresis (DEP) response of our bio-chips, making them usable in physiological buffers. In further studies we discovered a universal scaling of EP in the frequency domain ...


Impedance-Based Microfluidic Platform For Quantitative Biology, Amin Mansoorifar Jul 2019

Impedance-Based Microfluidic Platform For Quantitative Biology, Amin Mansoorifar

Mechanical Engineering Research Theses and Dissertations

Dielectric properties of biological cells are functions of cellular structure, content, state, and phenotype. Dielectric spectroscopy (DS) is a nondestructive method to characterize dielectric properties by measuring impedance data over a frequency range. This method has been widely used for various applications such as counting, sizing, and monitoring biological cells and particles. Recently, this method has been suggested to be utilized in various stages of the drug discovery process due to its low sample consumption and fast analysis time.

In this thesis, we have developed a lab-on-a-chip device that uses an electro-activated microwells array for capturing, making DS measurements on ...


Feedforward And Feedback Signals In The Olfactory System, Srimoy Chakraborty May 2019

Feedforward And Feedback Signals In The Olfactory System, Srimoy Chakraborty

Theses and Dissertations

The conglomeration of myriad activities in neural systems often results in prominent oscillations. The primary goal of the research presented in this thesis was to study effects of sensory stimulus on the olfactory system of rats, focusing on the olfactory bulb (OB) and the anterior piriform cortex (aPC). Extracellular electrophysiological measurements revealed distinct frequency bands of oscillations in OB and aPC. However, how these oscillatory fluctuations help the animal to process sensory input is not clearly understood. Here we show high frequency oscillations in olfactory bulb carry feedforward signals to anterior piriform cortex whereas feedback from the aPC is predominantly ...


Perturbation Based Decomposition Of Semg Signals, Rachel Huettinger Mar 2019

Perturbation Based Decomposition Of Semg Signals, Rachel Huettinger

Master's Theses and Project Reports

Surface electromyography records the motor unit action potential signals in the vicinity of the electrode to reveal information on muscle activation. Decomposition of sEMG signals for characterization of constituent motor unit action potentials in terms of amplitude and firing times is useful for clinical research as well as diagnosis of neurological disorders. Successful decomposition of sEMG signals would allow for pertinent motor unit action potential information to be acquired without discomfort to the subject or the need for a well-trained operator (compared with intramuscular EMG). To determine amplitudes and firing times for motor unit action potentials in an sEMG recording ...


Development Of A Myoelectric Detection Circuit Platform For Computer Interface Applications, Nickolas Andrew Butler Mar 2019

Development Of A Myoelectric Detection Circuit Platform For Computer Interface Applications, Nickolas Andrew Butler

Master's Theses and Project Reports

Personal computers and portable electronics continue to rapidly advance and integrate into our lives as tools that facilitate efficient communication and interaction with the outside world. Now with a multitude of different devices available, personal computers are accessible to a wider audience than ever before. To continue to expand and reach new users, novel user interface technologies have been developed, such as touch input and gyroscopic motion, in which enhanced control fidelity can be achieved. For users with limited-to-no use of their hands, or for those who seek additional means to intuitively use and command a computer, novel sensory systems ...


Development Of An Astrocyte/Glioma Co-Culture System For Measuring Cellular Dynamics, Urna Kansakar Feb 2019

Development Of An Astrocyte/Glioma Co-Culture System For Measuring Cellular Dynamics, Urna Kansakar

Doctoral Dissertations

Gliomas are brain tumors that primarily arise from glial cells. Gliomas account for 70% of the brain tumors and they are more prevalent in older adults. About 60% of the people with gliomas experience at least one seizure. Brain tumors can grow and metastasize to neighboring areas, thereby destroying normal brain cells. In a brain tumor microenvironment, both malignant cancer cells and healthy brain cells are present. Studies have shown that astrocytes may have a role in tumor growth in the brain. Monocultures cannot evaluate interactions between two cell types and does not accurately represent in vivo conditions. Thus, a ...


A Possible Link Between R-Wave Amplitude Alternans And T-Wave Alternans In Ecgs, Sahar Alaei Jan 2019

A Possible Link Between R-Wave Amplitude Alternans And T-Wave Alternans In Ecgs, Sahar Alaei

Theses and Dissertations--Biomedical Engineering

Sudden Cardiac Death (SCD) is the largest cause of natural deaths in the USA, accounting for over 300,000 deaths annually. The major reason for SCD is Ventricular Arrhythmia (VA). Therefore, there is need for exploration of approaches to predict increased risk for VA. Alternans of the T wave in the ECG (TWA) is widely investigated as a potential predictor of VA, however, clinical trials show that TWA has high negative predictive value but poor positive predictive value. A possible reason that TWA has a large number of false positives is that a pattern of alternans known as concordant alternans ...


A Brain-Computer Interface For Closed-Loop Sensory Stimulation During Motor Training In Patients With Tetraplegia, Sarah Helen Thomas Jan 2019

A Brain-Computer Interface For Closed-Loop Sensory Stimulation During Motor Training In Patients With Tetraplegia, Sarah Helen Thomas

Theses and Dissertations--Biomedical Engineering

Normal movement execution requires proper coupling of motor and sensory activation. An increasing body of literature supports the idea that incorporation of sensory stimulation into motor rehabilitation practices increases its effectiveness. Paired associative stimulation (PAS) studies, in which afferent and efferent pathways are activated in tandem, have brought attention to the importance of well-timed stimulation rather than non-associative (i.e., open-loop) activation. In patients with tetraplegia resulting from spinal cord injury (SCI), varying degrees of upper limb function may remain and could be harnessed for rehabilitation. Incorporating associative sensory stimulation coupled with self-paced motor training would be a means for ...


Design And Testing Of An Agonist-Antagonist Position-Impedance Controlled Myoelectric Prosthesis, Christopher Aymonin Jan 2019

Design And Testing Of An Agonist-Antagonist Position-Impedance Controlled Myoelectric Prosthesis, Christopher Aymonin

Theses and Dissertations

Intuitive prosthetic control is limited by the inability to easily convey intention and perceive physical requirements of the task. Rather than providing haptic feedback and allowing users to consciously control every component of manipulation, relegating some aspects of control to the device may simplify operation. This study focuses on the development and testing of a control scheme able to identify object stiffness and regulate impedance. The system includes an algorithm to detect the apparent stiffness of an object, a proportional nonlinear EMG control algorithm for interpreting a user’s desired grasp aperture, and an antagonistically acting impedance controller. Performance of ...


Translational Modeling Of Non-Invasive Electrical Stimulation, Dennis Quangvinh Truong Jan 2019

Translational Modeling Of Non-Invasive Electrical Stimulation, Dennis Quangvinh Truong

Dissertations and Theses

Seminal work in the early 2000’s demonstrated the effect of low amplitude non-invasive electrical stimulation in people using neurophysiological measures (motor evoked potentials, MEPs). Clinical applications of transcranial Direct Current Stimulation (tDCS) have since proliferated, though the mechanisms are not fully understood. Efforts to refine the technique to improve results are on-going as are mechanistic studies both in vivo and in vitro. Volume conduction models are being applied to these areas of research, especially in the design and analysis of clinical montages. However, additional research on the parameterization of models remains.

In this dissertation, Finite Element Method (FEM) models ...


Modeling And Simulation Methodologies For Spinal Cord Stimulation., Saliya Kumara Kirigeeganage Dec 2018

Modeling And Simulation Methodologies For Spinal Cord Stimulation., Saliya Kumara Kirigeeganage

Electronic Theses and Dissertations

The use of neural prostheses to improve health of paraplegics has been a prime interest of neuroscientists over the last few decades. Scientists have performed experiments with spinal cord stimulation (SCS) to enable voluntary motor function of paralyzed patients. However, the experimentation on the human spinal cord is not a trivial task. Therefore, modeling and simulation techniques play a significant role in understanding the underlying concepts and mechanics of the spinal cord stimulation. In this work, simulation and modeling techniques related to spinal cord stimulation were investigated. The initial work was intended to visualize the electric field distribution patterns in ...


A Biomechanical And Physiological Signal Monitoring System For Four Degrees Of Upper Limb Movement, Allison R. Goldman Sep 2018

A Biomechanical And Physiological Signal Monitoring System For Four Degrees Of Upper Limb Movement, Allison R. Goldman

Electronic Thesis and Dissertation Repository

A lack of adherence to prescribed physical therapy regimens in improper healing results in poor outcomes for those affected by musculoskeletal disorders (MSDs) of the upper limb. Societal and psychological barriers to proper adherence can be addressed through the system presented in this work consisting of the following components: an ambulatory biosignal acquisition sleeve, an electromyography (EMG) based motion repetition detection algorithm, and the design of a compatible capacitive EMG acquisition module.

The biosignal acquisition sleeve was untethered, unobtrusive to motion, contained only modular components, and collected biomechanical and physiological sensor data to form full motion profiles of the following ...


Computational Theories For Human Stereo Vision, Han Gao May 2018

Computational Theories For Human Stereo Vision, Han Gao

Electrical Engineering Theses and Dissertations

Binocular stereopsis refers to the ability to perceive depth, which has always been a central problem in perception since the time of da Vinci. The foremost theoretical difficulty that arises when attempting to understand how the visual system computes disparity is known as the correspondence or matching problem. Decades of research upon macaque primary visual cortex has shown that in each layer of the primary visual cortex (V1) long-range horizontal connections among striate cortex cells exist which integrate information from different parts of the visual field. Inspired by long-range horizontal connections in V1 and the Jeffress model, a time-delay neural ...


Chronic Nerve Interfacing Utilizing Graft-Embedded Regenerative Macro-Sieve Electrodes, Amrita Nishtala May 2018

Chronic Nerve Interfacing Utilizing Graft-Embedded Regenerative Macro-Sieve Electrodes, Amrita Nishtala

Engineering and Applied Science Theses & Dissertations

Custom-designed macro-sieve electrodes represent a novel means of facilitating chronic high specificity nerve stimulation needed to control distal nerve musculature and restore sensorimotor function. Implantation of these electrodes requires the transection of the nerve, which has shown to disrupt muscle fiber distribution. This present study assesses the feasibility of implementing these electrodes in an end-to-side nerve graft. The macro-sieve electrodes were fabricated and micro-surgically implanted into 3.2 cm nerve autografts harvested from the sciatic nerve of 12 male Lewis rats. Electrode-enabled nerve grafts were micro-surgically implanted in an end-to-side manner into donor rat sciatic nerves without the need for ...


Longitudinal Tracking Of Physiological State With Electromyographic Signals., Robert Warren Stallard May 2018

Longitudinal Tracking Of Physiological State With Electromyographic Signals., Robert Warren Stallard

Electronic Theses and Dissertations

Electrophysiological measurements have been used in recent history to classify instantaneous physiological configurations, e.g., hand gestures. This work investigates the feasibility of working with changes in physiological configurations over time (i.e., longitudinally) using a variety of algorithms from the machine learning domain. We demonstrate a high degree of classification accuracy for a binary classification problem derived from electromyography measurements before and after a 35-day bedrest. The problem difficulty is increased with a more dynamic experiment testing for changes in astronaut sensorimotor performance by taking electromyography and force plate measurements before, during, and after a jump from a small ...


Integration Of A Sensory Driven Model For Hand Grasp Function In 3d Printed Prostheses, Austin T. Hetherington Apr 2018

Integration Of A Sensory Driven Model For Hand Grasp Function In 3d Printed Prostheses, Austin T. Hetherington

Senior Theses

My Honors Thesis was completed through the Biomedical Engineering senior design project I worked on. Our project took a mechanically operated 3D printed prosthetic hand and automated the process by which it makes a grasp. The purpose of this project was to provide an affordable, automatic prosthetic hand to those either capable and incapable of wrist flexion. The current 3D printed prosthetic models require users to bend their wrist to initiate a simple grasp. However, our design took an alternative approach by using an EMG sensor placed on the ventral side of the forearm to record muscle activity, which, upon ...


Development Of Novel Models To Study Deep Brain Effects Of Cortical Transcranial Magnetic Stimulation, Farheen Syeda Jan 2018

Development Of Novel Models To Study Deep Brain Effects Of Cortical Transcranial Magnetic Stimulation, Farheen Syeda

Theses and Dissertations

Neurological disorders require varying types and degrees of treatments depending on the symptoms and underlying causes of the disease. Patients suffering from medication-refractory symptoms often undergo further treatment in the form of brain stimulation, e.g. electroconvulsive therapy (ECT), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS), or transcranial magnetic stimulation (TMS). These treatments are popular and have been shown to relieve various symptoms for patients with neurological conditions. However, the underlying effects of the stimulation, and subsequently the causes of symptom-relief, are not very well understood. In particular, TMS is a non-invasive brain stimulation therapy which uses time-varying ...


Neuropsychological And Morphometric Correlates Of Decision Making With The Coin Flip Task, Ashten Sherman Jan 2018

Neuropsychological And Morphometric Correlates Of Decision Making With The Coin Flip Task, Ashten Sherman

Honors Theses at the University of Iowa

The purpose of this study was to determine how older adults perform on a decision- making task (referred to as the Coin Flip Task), and how this performance correlates with demographic, neuropsychological, and brain morphometry variables. The study of decision making ability among older adults is important for several reasons. First, older adults frequently make “weighty” decisions as they age, such as important financial and medical decisions. When less than optimal decisions are made, it is difficult for the older adult to recover from or fix that decision given their relatively limited longevity. Second, decision making ability emanates from a ...


Eeg And Emg Sensorimotor Measurements To Assess Proprioception Following Acl Reconstruction, Teagan Frances Northrup Jan 2018

Eeg And Emg Sensorimotor Measurements To Assess Proprioception Following Acl Reconstruction, Teagan Frances Northrup

Honors Theses and Capstones

The Anterior Cruciate Ligament (ACL) is the primary source of rotational stability in the knee by preventing the tibia from sliding in front of the femur. When the ACL is torn, it typically must be repaired through reconstructive surgery which results in proprioceptive deficiencies in the knee. Proprioception plays an important role in understanding where one’s knee is in space, sensing movement and reacting accordingly. This study examines an alternative method of measuring proprioceptive responses to a stimulus (motion) by using electromyogram (EMG) and electroencephalogram (EEG) signals to observe muscle and brain activity. Two participants (one with an ACL ...


Electrochemical And Spectroscopic Study Of Peptide-Template Melanins, Daniel Courter, Olivia Rossi, Zhen Tian Jan 2018

Electrochemical And Spectroscopic Study Of Peptide-Template Melanins, Daniel Courter, Olivia Rossi, Zhen Tian

Honors Theses and Capstones

Melanins are organic polymers made up of 5,6-dihydroxyindole carboxylic acid (DHICA) and 5,6-dihydroxyindole (DHI). Biochemical systems synthesize melanins through a complex reaction pathway. Previous research exhibited that naturally-occurring melanins (NatMel) and their synthetic analogues (SynMel) can potentially serve as electrode materials for aqueous charge storage devices. Small surface area creates technical challenges for these melanins as charge storage materials. This research herein demonstrates that the structure of melanins can affect the charge storage capacities of monovalent Na+cations and divalent Mg2+ cations. 2-D sheet-like peptide melanins (PepMel) were synthesized into tripeptides consisting of aspartic acid (D), phenylalanine ...


Interfacing A Hirudo Medicinalis Retzius Cell With Insulated Gate Of Mosfet, Rachel M. Smith Dec 2017

Interfacing A Hirudo Medicinalis Retzius Cell With Insulated Gate Of Mosfet, Rachel M. Smith

Master's Theses and Project Reports

Much work has been done to study the external stimulation of nervous tissue as well as the transmission of neural signals to electronics. Peter Fromherz was one of the pioneers in this area of electrophysiology, with a series of experiments in the 1990s that aimed to characterize and optimize the interface between neural tissue and transistors. In this thesis, Kurt Sjoberg and I interfaced a Retzius cell isolated from a Hirudo medicinalis ganglion with the insulated gate of a MOSFET. The goal was to see change in membrane potential that could be related Fromherz’s original 1991 work. Our experimental ...


Computer-Aided Diagnoses (Cad) System: An Artificial Neural Network Approach To Mri Analysis And Diagnosis Of Alzheimer's Disease (Ad), Berizohar Padilla Cerezo Dec 2017

Computer-Aided Diagnoses (Cad) System: An Artificial Neural Network Approach To Mri Analysis And Diagnosis Of Alzheimer's Disease (Ad), Berizohar Padilla Cerezo

Master's Theses and Project Reports

Alzheimer’s disease (AD) is a chronic and progressive, irreversible syndrome that deteriorates the cognitive functions. Official death certificates of 2013 reported 84,767 deaths from Alzheimer’s disease, making it the 6th leading cause of death in the United States. The rate of AD is estimated to double by 2050. The neurodegeneration of AD occurs decades before symptoms of dementia are evident. Therefore, having an efficient methodology for the early and proper diagnosis can lead to more effective treatments.

Neuroimaging techniques such as magnetic resonance imaging (MRI) can detect changes in the brain of living subjects. Moreover, medical imaging ...


Characterization Of The High Frequency Alternating Current Block In The Rat Sciatic Nerve Using Cuff Electrodes And Macro-Sieve Electrodes, Soumyajit Ray Aug 2017

Characterization Of The High Frequency Alternating Current Block In The Rat Sciatic Nerve Using Cuff Electrodes And Macro-Sieve Electrodes, Soumyajit Ray

Engineering and Applied Science Theses & Dissertations

Tripolar cuff electrodes were designed, fabricated and non-chronically implanted in the sciatic nerve of two-month-old Lewis rats. A proximal constant current stimulus to the nerve was blocked by applying a high frequency sinusoidal signal to the distally placed tripolar cuff electrode. The frequency voltage characteristic of the blocking signal was obtained. Complete block was not achieved using variants of the tripolar cuff design and bipolar cuff electrodes. Single and dual macro-sieve electrode assemblies were designed, fabricated and chronically implanted in the sciatic nerve of Lewis rats. After a four-month period for regeneration four different electrode configurations were tested to enable ...


Developing An Imaging Biomarker To Detect Aberrant Brain Connectivity In Individual Patients, Esther Cox Apr 2017

Developing An Imaging Biomarker To Detect Aberrant Brain Connectivity In Individual Patients, Esther Cox

Master's Theses (2009 -)

Resting state functional MRI (rsfMRI) has been proven to be a valuable tool in clinical applications such as pre-surgical mapping, but there is not yet a functional and usable algorithm that can be used by physicians in a clinical setting to evaluate an individual patient for diseases and aberrant brain connectivity. If a physician wants to evaluate a patient in this way, the rsfMRI data must be looked at “by hand,” i.e. the physician must manually evaluate the data and identify the functional ICN’s and whether they are normal or aberrant. An algorithm that would automate this process ...


Development Of An Atlas-Based Segmentation Of Cranial Nerves Using Shape-Aware Discrete Deformable Models For Neurosurgical Planning And Simulation, Sharmin Sultana Apr 2017

Development Of An Atlas-Based Segmentation Of Cranial Nerves Using Shape-Aware Discrete Deformable Models For Neurosurgical Planning And Simulation, Sharmin Sultana

Computational Modeling and Simulation Engineering Theses & Dissertations

Twelve pairs of cranial nerves arise from the brain or brainstem and control our sensory functions such as vision, hearing, smell and taste as well as several motor functions to the head and neck including facial expressions and eye movement. Often, these cranial nerves are difficult to detect in MRI data, and thus represent problems in neurosurgery planning and simulation, due to their thin anatomical structure, in the face of low imaging resolution as well as image artifacts. As a result, they may be at risk in neurosurgical procedures around the skull base, which might have dire consequences such as ...


A Comprehensive Analysis On Eeg Signal Classification Using Advanced Computational Analysis, Kaushik Bhimraj Jan 2017

A Comprehensive Analysis On Eeg Signal Classification Using Advanced Computational Analysis, Kaushik Bhimraj

Electronic Theses and Dissertations

Electroencephalogram (EEG) has been used in a wide array of applications to study mental disorders. Due to its non-invasive and low-cost features, EEG has become a viable instrument in Brain-Computer Interfaces (BCI). These BCI systems integrate user's neural features with robotic machines to perform tasks. However, due to EEG signals being highly dynamic in nature, BCI systems are still unstable and prone to unanticipated noise interference. An important application of this technology is to help facilitate the lives of the tetraplegic through assimilating human brain impulses and converting them into mechanical motion. However, BCI systems are remarkably challenging to ...


Exploring The Production Of Extracellular Matrix By Astrocytes In Response To Mimetic Traumatic Brain Injury, Addison Walker Dec 2016

Exploring The Production Of Extracellular Matrix By Astrocytes In Response To Mimetic Traumatic Brain Injury, Addison Walker

Theses and Dissertations

Following injury to the central nervous system, extracellular modulations are apparent at

the site of injury, often resulting in a glial scar. Astrocytes are mechanosensitive cells, which can create a neuroinhibitory extracellular environment in response to injury. The aim for this research was to gain a fundamental understanding of the affects a diffuse traumatic brain injury has on the astrocyte extracellular environment after injury. To accomplish this, a bioreactor culturing astrocytes in 3D constructs delivered 150G decelerations with 20% biaxial strain to mimic a traumatic brain injury. Experiments were designed to compare the potential effects of media type, number of ...


Analog Spiking Neuromorphic Circuits And Systems For Brain- And Nanotechnology-Inspired Cognitive Computing, Xinyu Wu Dec 2016

Analog Spiking Neuromorphic Circuits And Systems For Brain- And Nanotechnology-Inspired Cognitive Computing, Xinyu Wu

Boise State University Theses and Dissertations

Human society is now facing grand challenges to satisfy the growing demand for computing power, at the same time, sustain energy consumption. By the end of CMOS technology scaling, innovations are required to tackle the challenges in a radically different way. Inspired by the emerging understanding of the computing occurring in a brain and nanotechnology-enabled biological plausible synaptic plasticity, neuromorphic computing architectures are being investigated. Such a neuromorphic chip that combines CMOS analog spiking neurons and nanoscale resistive random-access memory (RRAM) using as electronics synapses can provide massive neural network parallelism, high density and online learning capability, and hence, paves ...


Elbow Patients’ Data Collection And Analysis: An Examination Of Electromyography Healing Patterns, Raneem Haddara Oct 2016

Elbow Patients’ Data Collection And Analysis: An Examination Of Electromyography Healing Patterns, Raneem Haddara

Electronic Thesis and Dissertation Repository

Musculoskeletal conditions are the most common cause of severe long-term pain and physical disability, accounting for the highest disability costs of about $17 billion yearly. To provide better rehabilitation tactics, the knowledge gap between injuries and their healing mechanisms needs to be addressed. The use of electromyography (EMG) is very popular in detecting neuromuscular diseases or nerve lesions; however, there is limited knowledge available for quantifying healing patterns of EMG in orthopedic patients who have injured their joints, muscles, or bones. In order to quantify the progress of orthopedic patients and assess their neuromuscular health and muscle synergy patterns, EMG ...


Cortical Oscillations During A Lateral Balance Perturbation While Walking, Joseph Lee Oct 2016

Cortical Oscillations During A Lateral Balance Perturbation While Walking, Joseph Lee

Dissertations (2009 -)

The role of sensory systems in the cortical control of dynamic balance was examined using electroencephalography (EEG) recordings during balance perturbations while walking. Specifically, we examined the impact of sensory deficits on cortical oscillations using vibratory stimuli to suppress sensory feedback and by comparing cortical oscillations during balance perturbations while walking in people with sensory deficits associated with cervical myelopathy and neurologically intact controls. Balance during walking provides a rich framework for investigating cortical control using EEG during a functionally relevant task. While this approach is promising, substantial technical challenges remain in recording and processing EEG in the noisy, artifact ...