Biomedical Engineering and Bioengineering Commons^™

Network-Level Mechanisms Underlying Effects Of Transcranial Direct Current Stimulation (Tdcs) On Visuomotor Learning, Pejman Sehatpour, Clément Dondé, Matthew J. Hoptman, Johanna Kreither, Devin Adair, Elisa Dias, Blair Vail, Stephanie Rohrig, Gail Silipo, Javier Lopez-Calderon, Antigona Martinez, Daniel C. Javitt

Publications and Research

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation approach in which low level currents are administered over the scalp to influence underlying brain function. Prevailing theories of tDCS focus on modulation of excitation-inhibition balance at the local stimulation location. However, network level effects are reported as well, and appear to depend upon differential underlying mechanisms. Here, we evaluated potential network-level effects of tDCS during the Serial Reaction Time Task (SRTT) using convergent EEG- and fMRI-based connectivity approaches. Motor learning manifested as a significant (p <.0001) shift from slow to fast responses and corresponded to a significant increase in beta-coherence (p <.0001) and fMRI connectivity (p <.01) particularly within the visual-motor pathway. Differential patterns of tDCS effect were observed within different parametric task versions, consistent with network models. Overall, these findings demonstrate objective physiological effects of tDCS at the network level that result in effective behavioral modulation when tDCS parameters are matched to network-level requirements of the underlying task.

Analysis And Enhancement Of Human Cognitive Control Using Noninvasive Brain-Computer Interfaces, Soheil Borhani

Doctoral Dissertations

Cognitive control including attention and working memory are crucial to human daily life. Whether a civilian who walks across a street or a military service member who is responsible for navigating a mission, cognitive control is involved, entirely. This ability is subject to impairment. People with attention disorder are easily disposed to distraction and lacks the ability to maintain the focus to a task. Multiple treatment strategies have been suggested which most of them has been pharmaceutical. Evidently, the medical treatment has side effects for long-term use. Moreover, it has a risk of drug misuse. Another line of treatment is …

Assessment Of The Use Of Low Molecular Weight Diblock Copolymers For The Formation Of Stable, Tunable Droplet Interface Bilayers, Joseph Tawfik

Masters Theses

This thesis presents the use of diblock copolymers, poly(butadiene)-b-poly(ethylene oxide) (PB_m PEO_n) and poly(isoprene)-b-poly(ethylene oxide) (PI_mPEO_n), as amphiphilic molecular building blocks for the formation of synthetic polymer bilayer membranes using the droplet interface bilayer (DIB) technique. The DIB technique makes use of the self-assembly of amphiphilic macromolecules along oil-water droplet interfaces that can then be physically connected for the construction of liquid supported macromolecular bilayers at the droplet interface. These bilayer membranes are capable of hosting both naturally occurring and synthetic protein channels. This technique has been used to form synthetic bilayer membranes …

A Note From The Editor, Daphne Fauber

Ideas: Exhibit Catalog for the Honors College Visiting Scholars Series

This piece is a letter from Daphne Fauber, the editor of this issue of Ideas. In the letter, the editor introduces the work of Dr. Paschalis Gkoupidenis as well as the moment in time in which his Visiting Scholars talk occurs.

Engineering Electromagnetic Systems For Next-Generation Brain-Machine Interface, Brayan Ricardo Navarrete

FIU Electronic Theses and Dissertations

MagnetoElectric Nanoparticles (MENPs) are known to be a powerful tool for a broad range of applications spanning from medicine to energy-efficient electronics. MENPs allow to couple intrinsic electric fields in the nervous system with externally controlled magnetic fields. This thesis exploited MENPs to achieve contactless brain-machine interface (BMIs). Special electromagnetic devices were engineered for controlling the MENPs’ magnetoelectric effect to enable stimulation and recording. The most important engineering breakthroughs of the study are summarized below.

(I) Metastable Physics to Localize Nanoparticles: One of the main challenges is to localize the nanoparticles at any selected site(s) in the brain. The fundamental …

Introduction To Neuromorphic Computing, Sadid R. Khan

Ideas: Exhibit Catalog for the Honors College Visiting Scholars Series

Neuromorphic computing is an emerging field that has the potential to drastically influence every human’s life within the next decades. Neuromorphic computing explores the computing process of the brain and attempts to replicate it onto modern electronics. It offers improvements on current computer architecture, the von Neumann architecture, and will lead to more efficient computing, easier development of machine learning, and further integration of electronics and biology.

Update On The Use Of Transcranial Electrical Brain Stimulation To Manage Acute And Chronic Covid-19 Symptoms, Giuseppina Pilloni, Marom Bikson, Bashar W. Badran, Mark S. George, Steven A. Kautz, Alexandre Hideki Okano, Abrahão Fontes Baptista, Leigh E. Charvet

Publications and Research

The coronavirus disease 19 (COVID-19) pandemic has resulted in the urgent need to develop and deploy treatment approaches that can minimize mortality and morbidity. As infection, resulting illness, and the often prolonged recovery period continue to be characterized, therapeutic roles for transcranial electrical stimulation (tES) have emerged as promising non-pharmacological interventions. tES techniques have established therapeutic potential for managing a range of conditions relevant to COVID-19 illness and recovery, and may further be relevant for the general management of increased mental health problems during this time. Furthermore, these tES techniques can be inexpensive, portable, and allow for trained self-administration. Here, …

Characterization Of Neuronal Differentiation And Activity In Human-Induced Pluripotent Neural Stem Cells, Allison Biddinger

The Journal of Purdue Undergraduate Research

No abstract provided.

Computational Modeling Of The Human Brain For Mtbi Prediction And Diagnosis, Yanir Levy

Electronic Thesis and Dissertation Repository

Sports related concussions and mild traumatic brain injuries have seen an increase in frequency over the past decade. The creation of highly biofidelic computational head models is an important step in understanding the mechanisms of these mild brain injuries and preventing them. Hence, the purpose of this research is to combine state-of-the-art computational models, brain imaging modalities and traditional head injury assessment protocols to simulate and predict the brains responses during traumatic head impacts. A novel, atlas-based, parcellated axon fiber embedded head model was developed which allows for in-depth analysis of the brain’s structural connectome tracts for injury diagnosis and …

Admittance Method For Estimating Local Field Potentials Generated In A Multi-Scale Neuron Model Of The Hippocampus, Clayton S. Bingham, Javad Paknahad, Christopher Bc Girard, Kyle Loizos, Jean-Marie C. Bouteiller, Dong Song, Gianluca Lazzi, Theodore W. Berger

Engineering Faculty Articles and Research

Significant progress has been made toward model-based prediction of neral tissue activation in response to extracellular electrical stimulation, but challenges remain in the accurate and efficient estimation of distributed local field potentials (LFP). Analytical methods of estimating electric fields are a first-order approximation that may be suitable for model validation, but they are computationally expensive and cannot accurately capture boundary conditions in heterogeneous tissue. While there are many appropriate numerical methods of solving electric fields in neural tissue models, there isn't an established standard for mesh geometry nor a well-known rule for handling any mismatch in spatial resolution. Moreover, the …

Validation Of Nanosecond Pulse Cancellation Using A Quadrupole Exposure System, Hollie A. Ryan

Biomedical Engineering Theses & Dissertations

Nanosecond pulsed electric fields (nsPEFs) offer a plethora of opportunities for developing integrative technologies as complements or alternatives to traditional medicine. Studies on the biological effects of nsPEFs in vitro and in vivo have revealed unique characteristics that suggest the potential for minimized risk of complications in patients, such as the ability of unipolar nsEPs to create permanent or transient pores in cell membranes that trigger localized lethal or non-lethal outcomes without consequential heating. A more recent finding was that such responses could be diminished by applying a bipolar pulse instead, a phenomenon dubbed bipolar cancellation, paving the way …

Visually Evoked Responses Are Enhanced When Engaging In A Video Game, Jason J. Ki, Lucas C. Parra, Jacek P. Dmochowski

Publications and Research

While it is well known that vision guides movement, less appreciated is that the motor cortex also provides input to the visual system. Here, we asked whether neural processing of visual stimuli is acutely modulated during motor activity, hypothesizing that visual evoked responses are enhanced when engaged in a motor task that depends on the visual stimulus. To test this, we told participants that their brain activity was controlling a video game that was in fact the playback of a prerecorded game. The deception, which was effective in half of participants, aimed to engage the motor system while avoiding evoked …

Secretion Of Proteins And Antibody Fragments From Transiently Transfected Endothelial Progenitor Cells, Loree Heller, Reynald Thinard, Melanie Chevalier, Sezgi Arpag, Yu Jing, Ruth Greferath, Richard Heller, Claude Nicolau

Bioelectrics Publications

In neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis and amyotrophic lateral sclerosis, neuroinflammation can lead to blood-brain barrier (BBB) breakdown. After intravenous or intra-arterial injection into mice, endothelial progenitor cells (EPCs) home to the damaged BBB to promote neurovascular repair. Autologous EPCs transfected to express specific therapeutic proteins offer an innovative therapeutic option. Here, we demonstrate that EPC transfection by electroporation with plasmids encoding the reporter protein GFP or an anti-beta-amyloid antibody fragment (Fab) leads to secretion of each protein. We also demonstrate the secreted anti-beta-amyloid Fab protein functions in beta-amyloid aggregate solubilization.

Functional Connectivity Of Eeg Is Subject-Specific, Associated With Phenotype, And Different From Fmri, Maximilian Nentwich, Lei Ai, Jens Madsen, Qawi K. Telesford, Stefan Haufe, Michael P. Milham, Lucas C. Parra

Publications and Research

A variety of psychiatric, behavioral and cognitive phenotypes have been linked to brain ‘’functional connectivity’’ -- the pattern of correlation observed between different brain regions. Most commonly assessed using functional magnetic resonance imaging (fMRI), here, we investigate the connectivity-phenotype associations with functional connectivity measured with electroencephalography (EEG), using phase-coupling. We analyzed data from the publicly available Healthy Brain Network Biobank. This database compiles a growing sample of children and adolescents, currently encompassing 1657 individuals. Among a variety of assessment instruments we focus on ten phenotypic and additional demographic measures that capture most of the variance in this sample. The largest …

Can Transcranial Electrical Stimulation Motor Threshold Estimate Individualized Tdcs Doses Over The Prefrontal Cortex? Evidence From Reverse-Calculation Electric Field Modeling, Kevin A. Caulfield, Bashar W. Badran, Xingbao Li, Marom Bikson, Mark S. George

Publications and Research

No abstract provided.

A Comparison Of Neural Activity For Peripersonal And Extrapersonal Viewing In Real And Virtual Environments, Olivia Eustice

Honors Theses

This study involved a series of tests comparing the similarities and differences in neural activity at a subject’s peripheral and extrapersonal space in the real environment and virtual reality. We hypothesized that there would be similar brain activity at each of these environments depending on the focal distance of an object from the participant. Peripheral space is the visual space that is a reachable distance from a person. It has an overall neural pattern in the dorsal stream of the brain. Extrapersonal space is the visual space that does not directly surround a person and cannot be directly acted on. …

Probing Nanoelectroporation And Resealing Of The Cell Membrane By The Entry Of Ca2+ And Ba2+ Ions, Wenfei Bo, Mantas Silkunas, Uma Mangalanathan, Vitalij Novickij, Maura Casciola, Iurii Semenov, Shu Xiao, Olga N. Pakhomova, Andrei G. Pakhomov

Bioelectrics Publications

The principal bioeffect of the nanosecond pulsed electric field (nsPEF) is a lasting cell membrane permeabilization, which is often attributed to the formation of nanometer-sized pores. Such pores may be too small for detection by the uptake of fluorescent dyes. We tested if Ca²⁺, Cd²⁺, Zn²⁺, and Ba²⁺ ions can be used as nanoporation markers. Time-lapse imaging was performed in CHO, BPAE, and HEK cells loaded with Fluo-4, Calbryte, or Fluo-8 dyes. Ca²⁺ and Ba²⁺ did not change fluorescence in intact cells, whereas their entry after nsPEF increased fluorescence within <1 ms. The threshold for one 300-ns pulse was at 1.5–2 kV/cm, much lower than >7 …

Mechanical Analysis Of In Vitro Tbi Models, Dana Hamed

Honors Scholar Theses

This work details the damage done to cells when mechanically hit. The goal was to mechanically analyze in vitro traumatic brain injury (TBI) models. Parts were designed in SolidWorks to create the machine that is used to induce this damage on the cells. A force applicator that uses a 3D-printed micro-hammer to apply force on the brain cells that are being tested was created. Mechanical trauma experimentation was performed with the force applicator, while a high-speed camera recorded the damage, in order to analyze TBI models. Displacement along the scaffold can be tracked from multiple video frames. With these results, …

Transcranial Electrical Stimulation Motor Threshold Can Estimate Individualized Tdcs Dosage From Reverse-Calculation Electric-Field Modeling, Kevin A. Caulfield, Bashar W. Badran, William H. Devries, Philipp M. Summers, Emma Kofmehl, Xingbao Li, Jeffrey J. Borckardt, Marom Bikson, Mark S. George

Publications and Research

Background

Unique amongst brain stimulation tools, transcranial direct current stimulation (tDCS) currently lacks an easy or widely implemented method for individualizing dosage.

Objective

We developed a method of reverse-calculating electric-field (E-field) models based on Magnetic Resonance Imaging (MRI) scans that can estimate individualized tDCS dose. We also evaluated an MRI-free method of individualizing tDCS dose by measuring transcranial magnetic stimulation (TMS) motor threshold (MT) and single pulse, suprathreshold transcranial electrical stimulation (TES) MT and regressing it against E-field modeling. Key assumptions of reverse-calculation E-field modeling, including the size of region of interest (ROI) analysis and the linearity of multiple E-field …

Enhanced Surface Electrical Neurostimulation (Esens): A Non-Invasive Platform For Peripheral Neuromodulation, Andres Eduardo Pena

FIU Electronic Theses and Dissertations

Electrical stimulation of peripheral afferents has been used to study the sensory neural code and restore lost sensory function after amputation. Recently, implantable neural interfaces have prompted multiple breakthroughs in artificial somatosensory feedback for individuals with amputation, resulting in functional and psychological benefits. Although promising, the invasive nature of these approaches limits wide clinical applications, hindering the development of advanced neuromodulation strategies for intuitive sensory feedback. Transcutaneous (surface) stimulation is a potential non-invasive alternative. However, traditional surface stimulation methods are hampered by inadequate electrode and stimulation parameter fitting, localized discomfort, poor selectivity, and limited percept modulation.

An enhanced surface electrical …

Transcutaneous Auricular Vagus Nerve Stimulation-Paired Rehabilitation For Oromotor Feeding Problems In Newborns: An Open-Label Pilot Study, Bashar W. Badran, Dorothea D. Jenkins, Daniel Cook, Sean Thompson, Morgan Darcy, William H. Devries, Georgia Mappin, Philipp Summers, Marom Bikson, Mark S. George

Publications and Research

Neonates born premature or who suffer brain injury at birth often have oral feeding dysfunction and do not meet oral intake requirements needed for discharge. Low oral intake volumes result in extended stays in the hospital (>2 months) and can lead to surgical implant and explant of a gastrostomy tube (G-tube). Prior work suggests pairing vagus nerve stimulation (VNS) with motor activity accelerates functional improvements after stroke, and transcutaneous auricular VNS (taVNS) has emerged as promising noninvasive form of VNS. Pairing taVNS with bottle-feeding rehabilitation may improve oromotor coordination and lead to improved oral intake volumes, ultimately avoiding the …

A Robust Lpc Filtering Method For Time-Resolved Morphology Of Eeg Activity Analysis, Jin Xu, Mark Davis, Ruairí De Fréin

Conference Papers

This paper introduces a new time-resolved spectral analysis method based on Linear Prediction Coding (LPC) method that is particularly suited to the study of the dynamics of EEG (Electroencephalogram) activity. The spectral dynamic of EEG signals can be challenging to analyse as they contain multiple frequency components and are often heavily corrupted by noise. Furthermore, the temporal and spectral resolution that can be achieved is limited by the Heisenberg-Gabor uncertainty principle [1]. The method described here is based on a z-plane analysis of the poles of the LPC which allows us to identify and estimate the frequency of the dominant …

Enhanced Tes And Tdcs Computational Models By Meninges Emulation, Jimmy Jiang, Dennis Q. Truong, Zeinab Esmaeilpour, Yu Huang, Bashar W. Badran, Marom Bikson

Publications and Research

Objective. Understanding how current reaches the brain during transcranial electrical stimulation (tES) underpins efforts to rationalize outcomes and optimize interventions. To this end, computational models of current flow relate applied dose to brain electric field. Conventional tES modeling considers distinct tissues like scalp, skull, cerebrospinal fluid (CSF), gray matter and white matter. The properties of highly conductive CSF are especially important. However, modeling the space between skull and brain as entirely CSF is not an accurate representation of anatomy. The space conventionally modeled as CSF is approximately half meninges (dura, arachnoid, and pia) with lower conductivity. However, the resolution …

Electrotransfer Of Il-15/Il-15rα Complex For The Treatment Of Established Melanoma, Shawna A. Shirley, Cathryn G. Lundberg, Richard Heller

Bioelectrics Publications

Gene electrotransfer (GET) is a safe, reliable, and effective method of delivering plasmid DNA (pDNA) to solid tumors. GET has been previously used to deliver interleukin-15 (IL-15) to mouse melanoma, resulting in long-term tumor regression and the survival of a percentage of treated animals after challenge. To enhance this effect, we evaluated modulating the expression levels of IL-15 and co-expressing its receptor, IL-15Rα. GET was used to deliver plasmids encoding IL-15 and IL-15Rα to established B16.F10 tumors on days 0, 4, and 7. Two delivery protocols that yielded different expression profiles were utilized. Mice that were tumor-free for 50 days …

High Frequency Oscillations In The Epileptic Brain: Accurate Detection, Effect Of Vigilance State, And Sample Size Considerations, Amir Fared Partu Al-Bakri

Theses and Dissertations--Biomedical Engineering

About a third of all epilepsy patients may experience seizures that are resistant to medication. Surgical resection may be an option for some of these patients, but localization of the epileptogenic zone is difficult and expensive. For this process, the seizures must be observed and recorded in a clinical setting over several days. High-frequency oscillations (HFOs) have emerged as a possible biomarker for predicting the epileptogenic zone from a brief interictal recording of brain electrical activity without having to wait for seizures. The broad objective of this dissertation is to devise methods and criteria for accurate detection, sampling and localization …

Effects Of Weak Electric Fields On Long-Term Synaptic Plasticity, Gregory Kronberg

Dissertations and Theses

Transcranial direct current stimulation (tDCS) is a technique where a weak direct electrical current is applied to the scalp with the goal of stimulating the brain. There is tremendous interest in the use of tDCS for treating brain disorders and improving brain function. However, the effects of tDCS have been highly variable across studies, leading to a debate over its efficacy. A major challenge is therefore to design tDCS protocols that yield predictable effects, which will require a better understanding of its basic mechanisms of action. One commonly discussed mechanism is that tDCS may alter synaptic plasticity, but the biophysics …

Thermal Analysis Of Infrared Irradiation-Assisted Nanosecond-Pulsed Tumor Ablation, James Hornef, Chelsea M. Edelblute, Karl H. Schoenbach, Richard Heller, Siqi Guo, Chunqi Jiang

Bioelectrics Publications

Nanosecond Pulsed Electric Fields (nsPEF) have the potential to treat a variety of cancer types including melanoma, pancreatic and lung squamous cancers. Recent studies show that nsPEF-based cancer therapy may be improved further with the assistance of moderate heating of the target. A feedbacklooped heating system, utilizing a 980-nm fiber optic laser, was integrated into nsPEF electrodes for tumor ablation. The laser beam profile was determined to be Gaussian using a knife-edge technique. Thermal properties of the biological target were evaluated based on the treatment area, penetration depth and thermal distribution due to laser irradiation with or without nsPEF. Synergistic …

The Effect Of Intermittent Theta Burst Stimulation On Biceps Corticomotor Excitability In Non-Impaired Individuals And Individuals With Tetraplegia, Blaize Majdic

Theses and Dissertations

Neuromodulation of the primary motor cortex (M1) in pair with physical therapy may be a promising method for improving motor outcomes after spinal cord injury (SCI). Increased excitability of the corticospinal motor pathways (i.e. corticomotor excitability) has shown to be associated with improved motor learning and skill acquisition. Intermittent theta burst stimulation (iTBS) is a form of non-invasive brain stimulation which can increase corticomotor excitability, as measured by an increase in the amplitude of motor evoked potentials (MEPs). However, the ability for iTBS to increase the corticomotor excitability of proximal muscles such as the biceps, and muscles affected by spinal …