Biomedical Engineering and Bioengineering Commons^™

Offset Electrodes For Enhanced Neural Recording In Microchannels, Iian Black

FIU Electronic Theses and Dissertations

Microchannel electrodes have emerged in recent years as promising interfaces for recording signals in peripheral nerves. Unlike many technologies, microchannels maintain stable long-term connections and can record activity in individual or small groups of axons. Unfortunately, a traditional symmetrical mid-channel electrode configuration, designed to reduce noise artifacts, prevents microchannels from being used to distinguish between signals traveling in opposite directions. This is a profound limitation given that most nerves contain a mix of efferent and afferent axons and microchannels were initially conceived and later used as the basic building block in arrays designed to record bi-directional neural traffic in regenerated …

Synergistic Activation Of Inspiratory Muscles By An Adaptive Closed-Loop Controller, Rabeya Zinnat Adury

FIU Electronic Theses and Dissertations

During diaphragmatic pacing reverse recruitment of muscle fibers causes muscle fatigue. Current diaphragmatic pacing paradigms also do not permit sigh-like behavior. In spontaneously breathing anesthetized rats, studies were carried out to determine if synergized pacing of external intercostal muscles and the diaphragm would increase the efficiency of diaphragm stimulation and thus a) achieve the desired ventilatory breath volume profile with reduced diaphragm muscle fatigue, and/or b) be able to elicit sigh-like behavior by periodically increasing stimulation. Under combined inspiratory muscle stimulation, a fatigue index calculated for the diaphragm muscle (n=6 rats) was significantly lower (p<0.05) than in the …

Measuring Collagen Arrangement And Its Relationship With Preterm Birth Using Mueller Matrix Polarimetry, Joseph James Chue-Sang

FIU Electronic Theses and Dissertations

Preterm birth (PTB) is defined as delivery prior to 37 weeks of gestation. It is the leading cause of infant death worldwide, responsible for infant neurological disorders, long-term cognitive impairment, as well as chronic health issues involving the auditory, visual, digestive, and respiratory systems. In expectant mothers, causes for PTB can include infection, inflammation, vascular disease, short intervals between pregnancies, multiple gestations and genetic factors. In the U.S., PTB occurs in over 11% of births and at an elevated 18.1% in Miami-Dade County, FL; while in the developing world the incidence of PB is over 15%. Early identification of at-risk …

Adaptive Closed-Loop Neuromorphic Controller For Use In Respiratory Pacing, Ricardo Siu

FIU Electronic Theses and Dissertations

Respiratory pacing can treat ventilatory insufficiency through electrical stimulation of the respiratory muscles, or the respective innervating nerves, to induce ventilation. It avoids some of the adverse effects associated with mechanical ventilation such as risk of diaphragm atrophy and lung damage. However, current respiratory pacing systems provide stimulation in an open-loop manner. This often requires users to undergo frequent tuning sessions with trained clinicians if the specified stimulation parameters are unable to induce sufficient ventilation in the presence of time-varying changes in muscle properties, chest biomechanics, and metabolic demand. Lack of adaptation to these changes may lead to complications arising …

The Neural Recruitment Of Executive Function In Monolingual Versus Bilingual Preterm-Born Children: An Fnirs Study, Caitlyn F. Myland

FIU Electronic Theses and Dissertations

Premature-birth is defined by the World Health Organization as birth less than 37 weeks. These children are particularly susceptible deficiencies in executive functioning (EF) as compared to term-born children. It has yet to be explored whether bilingualism might also give an edge to preterm-born-children (PBC) in EF. The present study aims to fill this gap by examining the EF of bilingual versus monolingual preterm-born children in Miami-Dade County. All 16 children were right-handed, ages 6-7, and born before 35 weeks. Results showed that both groups performed about the same on the Dimensional Change Card Sort (DCCS) and Go/No Go (GNG) …

Multiscale Model Of Cerebral Blood Flow Control: Application To Small Vessel Disease And Cortical Spreading Depression, Arash Moshkforoush

FIU Electronic Theses and Dissertations

An in-time delivery of oxygen-rich blood into areas of high metabolic demand is pivotal in proper functioning of the brain and neuronal health. This highly precise communication between neuronal activity and cerebral blood flow (CBF) is termed as neurovascular coupling (NVC) or functional hyperemia. NVC is disrupted in major pathological conditions including Alzheimer’s disease, dementia, small vessel pathologies (SVD) and cortical spreading depression. Despite the utmost importance of NVC, its underlying mechanisms are not fully understood. This dissertation presents a multiscale mathematical modeling framework for studying unresolved mechanisms of NVC with major focus on K⁺ ions as a mediator …

The Effect Of Proteome And Lipidome On The Behavior Of Membrane Bound Systems In Thermally-Assisted Acoustophoresis, Elnaz Mirtaheri

FIU Electronic Theses and Dissertations

Changes in the biomechanical properties of cells accompanying the development of various pathological conditions have been increasingly reported as biomarkers for various diseases, including cancers. In cancer cells, the membrane properties have been altered compared to their healthy counterparts primarily due to proteomic and lipidomic dysregulations conferred by the underlying pathology. The separation and selective recovery of these cells or extracellular vesicles secreted from such cells is of high diagnostic and prognostic value.

In this dissertation, the research builds on thermally-assisted acoustophoresis technique which was developed in our laboratory for the separation of vesicles of the same size, charge and …