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 …

Doctor’S Cyclo-Massage – Cycloidal Vibration Therapy, Monserrat G. Otarola

Undergraduate Research at FIU (URFIU) Conference

Body pain can be one of the most common reasons for visits to the doctor. It can be present in many body locations and be caused by different reasons, such as tension, stress, fatigue or other medical conditions. In many cases, users suffering from body pain, muscle stiffness and neuropathies have no reliable solution in their everyday lives to alleviate their symptoms. The project will investigate Doctor’s Cyclo-Massage in order to detect and analyze the current failures in the field that are compromising reliability and functionality of the device, to perform a redesign that will mitigate the mechanical and electrical …

Correlation Between Magnetic Resonance Imaging-Based Markers Of Spinal Cord Integrity And Muscle Composition In Individuals With Chronic Spinal Cord Injury, Kelly Nair Rojas

Undergraduate Research at FIU (URFIU) Conference

The purpose of this research project was to investigate potential relationships between magnetic resonance imaging (MRI)-based measures of the spinal cord and MRI-based measures of muscle physiology in 14 individuals with spinal cord injury. Such relationships – or lack thereof – may hold prognostic value for determining recovery of motor function in this population. We used simple linear regression as an initial tool to determine whether measures of damage to the spinal cord were associated with changes in muscle composition, including intramuscular fat and the diffusivity of fluid within the muscle. These muscle composition metrics are potential markers of denervation, …

Ion Channel Expression Regulation By Sodium And Potassium In Vascular Endothelial Cells, Monica Karas

Undergraduate Research at FIU (URFIU) Conference

Introduction: Changes in the expression of ion channels, and of genes involved in membrane potential (Vm) homeostasis and Ca2 +s ignaling have been associated with pathological conditions such as hypertension (1,2,3,4). Little is known, however, for the mechanisms that regulate the expression of the approximately 400 genes encoding for subunits of the 200-250 ion channels. There is evidence that a feedback system exists, capable of sensing changes in cell electrophysiology (5 ) that leads to altering ion channel transcription levels. The variable(s) that are sensed and controlled have not been established although Na+ / K+ sensitive transcriptome has been reported …

Development And Validation Of A Smartphone-Based Near-Infrared Optical Imaging Device To Measure Physiological Changes In-Vivo, Kacie Kaile, Anuradha Godavarty

Department of Biomedical Engineering Faculty Publications

Smartphone-based technologies for medical imaging purposes are limited, especially when it involves the measurement of physiological information of the tissues. Herein, a smartphone-based near-infrared (NIR) imaging device was developed to measure physiological changes in tissues across a wide area and without contact. A custom attachment containing multiple multi-wavelength LED light sources (690, 800, and 840 nm; and <4 mW of optical power per LED), source driver, and optical filters and lenses was clipped onto a smartphone that served as the detector during data acquisition. The ability of the device to measure physiological changes was validated via occlusion studies on control subjects. Noise removal techniques using singular value decomposition algorithms effectively removed surface noise and distinctly differentiated the physiological changes in response to occlusion. In the long term, the developed smartphone-based NIR imaging device with capabilities to capture physiological changes will be a great low-cost alternative for clinicians and eventually for patients with chronic ulcers and bed sores, and/or in pre-screening for potential ulcers in diabetic subjects.

Optical Phantoms For Biomedical Polarimetry: A Review, Joseph Chue-Sang, Mariacarla Gonzalez, Angie Pierre, Megan Laughrey, Ilyas Saytashev, Tatiana Novikova, Jessica C. Ramella-Roman

Department of Biomedical Engineering Faculty Publications

Calibration, quantification, and standardization of the polarimetric instrumentation, as well as interpretation and understanding of the obtained data, require the development and use of well-calibrated phantoms and standards. We reviewed the status of tissue phantoms for a variety of applications in polarimetry; more than 500 papers are considered. We divided the phantoms into five groups according to their origin (biological/nonbiological) and fundamental polarimetric properties of retardation, depolarization, and diattenuation. We found that, while biological media are generally depolarizing, retarding, and diattenuating, only one of all the phantoms reviewed incorporated all these properties, and few considered at least combined retardation and …

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 …