Biomedical Engineering and Bioengineering Commons^™

Development And Implementation Of Telemetry Devices To Identify And Characterize Sources Of Intraocular Pressure Variability In Rats, Christina M. Nicou

USF Tampa Graduate Theses and Dissertations

Eye health depends partially on intraocular pressure (IOP) as abnormal levels can lead to ocular tissue damage. Glaucoma is a neurodegenerative disease that affects nearly 80 million people worldwide [1]. It is associated with elevated IOP, which can lead to irreversible blindness. Relatively little is known about IOP dynamics and the physiological factors that affect it as IOP is typically monitored using tonometry. Tonometry is a common tool used by clinicians and researchers to measure IOP noninvasively. It provides a good estimate of IOP mean but not variance because data collection takes time. Readings can also be influenced by subject …

Assistive Technologies For Independent Navigation For People With Blindness, Howard Kaplan

USF Tampa Graduate Theses and Dissertations

The necessity for individuals to navigate from location to location is essential to daily life. The majority of humans use sight as the main source for determining how to move through their environment. However, there is a large population of people who are either blind or living with low vision. Based on a 2017 National Health Survey there are around 27 million adult Americans that have experienced vision loss (National Center for Health Statistics, 2017). According to the Eye Diseases Prevalence Research Group there are 3.4 million Americans 40 years and older that are legally blind or visually impaired (EDPRG, …

Development Of A Bipolar Radiofrequency Ablation Device For Renal Denervation, Noel Perez

USF Tampa Graduate Theses and Dissertations

The American Heart Association (AHA) reported in March 2020, hypertension (HT) is a major risk factor for cardiovascular diseases and heart stroke. Resistant hypertension (RH) is a subset of HT and affects 11-16% of hypertensive patients. RH is diagnosed when a patient cannot achieve blood pressure control despite taking three or more medications and is a serious clinical management challenge.

Renal denervation (RD) using radiofrequency (RF) ablation is an accepted form of RH therapy. RD devices are typically delivered through femoral access into the renal artery with the assistance of a standard guided sheath. In the European Union (EU), the …

Cancer Biomarker Detection In Human Plasma By Integrating Surface Acoustic Wave And Metal-Enhanced Fluorescence, Yuqi Huang

USF Tampa Graduate Theses and Dissertations

This thesis includes data and discussion about the technique of metal-enhanced fluorescence (MEF) to lower the detection limit of carcinoembryonic antigen (CEA). The detection limit goes down to 100pg/mL level when using MEF substrate made by rapid thermally annealed silver film covered by silica, which has great promise in diagnosing certain types of cancer that uses CEA as detection biomarker, such as pancreatic cancer and colon cancer. To further address the issue of background noises from non-specifically bound proteins (NSB) in complex media, such as plasma, serum, urine and blood, MEF is integrated with surface acoustic wave (SAW) streaming in …

Development Of A Monolithic Implantable Neural Interface From Cubic Silicon Carbide And Evaluation Of Its Mri Compatibility, Mohammad Beygi

USF Tampa Graduate Theses and Dissertations

One of the main issues with micron-sized intracortical neural interfaces (INIs) is their long-term reliability, with one major factor stemming from device material failure caused by the heterogeneous integration of multiple materials used to realize the implant. Single crystalline cubic silicon carbide (3C-SiC) is a semiconductor material that has been long recognized for its mechanical robustness and chemical inertness. It has the benefit of demonstrated biocompatibility, which makes it a promising candidate for chronically-stable, implantable INIs. In the first section of this dissertation, the fabrication and initial electrochemical characterization of a monolithic, Michigan-style 3C-SiC microelectrode array (MEA) probe is reported. …

Design And Development Of A Wireless Eeg System Integrated Into A Football Helmet, Akshay V. Dunakhe

USF Tampa Graduate Theses and Dissertations

In the United States, approximately 2.8 million Traumatic Brain Injuries (TBI) occur annually. Out of these 2.8 million occurrences, 280,000 injuries are caused by sports and recreational activities. The actual number can be significantly higher since mild TBI are often unrecorded. These injuries not only cause physical damage to players, but they are also one of the leading causes of a player’s retirement from a sports career. While working with TBIs, it is vital to detect the concussion at its first occurrence, termed as a “primary concussion.” If the primary concussion goes undetected, the player may continue to play the …

Demonstration Of Monolithic-Silicon Carbide (Sic) Neural Devices, Evans K. Bernardin

USF Tampa Graduate Theses and Dissertations

Brain Machine Interfaces (BMI) provide a communication pathway between the electrical conducting units of the brain (neurons) and external devices. BMI technology may provide improved neurological and physiological functions to patients suffering from disabilities due to damaged nervous systems. Unfortunately, microelectrodes used in Intracortical Neural Interfaces (INI), a subset of the BMI device family, have yet to demonstrate long-term in vivo performance due to material, mechanical and electrical failures. Many state-of-the-art INI devices are constructed using stacks of multiple materials, such as silicon (Si), titanium (Ti), platinum (Pt), parylene C, and polyimide. Not only must each material tolerate the biological …

Integration And Cross-Coupling Of A Notched-Turbine Symbiotic Power Source For Implantable Medical Devices, Samuel Perez

USF Tampa Graduate Theses and Dissertations

The purpose of this research is to design and integrate a symbiotic notched-turbine energy generator for implantation as a cross-coupled system capable of continuously and perpetually powering an electronic implantable medical device (IMD), which is a device designed to operate inside the body of a higher mammal to enhance, correct or provide the body with a function that has deviated from the norm or has stopped altogether. The list of IMDs available for implantation keeps growing every year, one of the newest being the VBLOC, produced by EnteroMedics®, and approved by the Food and Drug Administration (FDA) on January 15th, …

Embedded System Design Of Low-Power Wearable Bioelectronic Devices, Matthew S. Hopper

USF Tampa Graduate Theses and Dissertations

The miniaturization of electronics in modern times has enabled the possibility of creating a “continuity of care” using small wearable bioelectronic devices. Using wearable devices, such as the Fitbit or Garmin fitness trackers, allows for the exchange of data between devices which can be used to improve the accuracy of data analysis and thus patient health.

In this thesis work, three wearable bioelectronic devices are proposed: an EOG-based eye-gaze tracking assistive technology device for the physically disabled to control a computer cursor, a battery-operated miniaturized polysomnograph that can store and transmit data wirelessly to sleep technicians and a trauma-detecting personal …

A High Accuracy Microwave Radiometric Thermometer To Measure Internal Body Temperature, Michael D. Grady

USF Tampa Graduate Theses and Dissertations

The Center for Disease Control and Prevention (CDC) released heat illness data which highlighted that ~29 heat stress hospitalizations and ~3 heat-related deaths occurred every day during the summer months within the US from years 2000 to 2014. Heatstroke- the most severe form of heat illness which oftentimes lead to death- has been cited to be entirely preventable if a timely intervention is introduced. This dissertation uses microwave radiometric thermometry to perform wireless non-invasive internal body temperature monitoring which can enable intervention methods that help to prevent deaths associated with heat-illness.

Overall, this dissertation develops a comprehensive closed-form analytical radiometric …

Rf Sensing System For Continuous Blood Glucose Monitoring, Fabiola Araujo Cespedes

USF Tampa Graduate Theses and Dissertations

The purpose of this research was to design a blood glucose sensing system based on the induced shift in the resonant frequency of an antenna patch operating in the ISM band (5.725 – 5.875 GHz). The underlying concept is the fact that when a person has variations in their blood glucose levels, the permittivity of their blood varies accordingly. This research analyzed the feasibility of using an antenna patch as a blood glucose sensing device in three configurations: 1) as an implantable active sensor, 2) as an implantable passive antenna sensor, and 3) as a non-invasive sensor. In the first …

Characterization Of Surface Charges And Compensating Charges For Gene Delivery To Tissue, Ravi Shanmugha Preethi Vangapattu

USF Tampa Graduate Theses and Dissertations

Ever since the discovery of DNA, there has been many pathologies identified effecting mankind. With the development in technology, there are many methods to alleviate these pathologies. One such is gene therapy or gene delivery. It is a process of introducing some foreign material into the body to correct the effected cells. In principle, it is a modern method to cure cells or a method to transfer nucleic acid into a cell to treat specific cells in the body. The process of delivering a genetic material is carried out using vectors, namely, viral vectors and non-viral vectors. In viral vectors, …

Simulation Studies On Ecg Vector Dipole Extraction In Liquid Medium, Pratheek Michael

USF Tampa Graduate Theses and Dissertations

To circumvent some inherent problems in the conventional ECG, this research reinvestigates an ‘unassisted’ approach which enables ECG measurement without the placement of leads on the body. Employed in this research is a widely accepted assumption that the electrical activity of the heart may be represented, largely, by a 3-D time-varying current dipole (3D-CD). From the PhysioBank database, mECG and fECG data were obtained, and Singular Value Decomposition (SVD) was performed to estimate the time-varying Vector ECG dipole. To determine the sensing matrix responsible for transforming the activity of the 3D-CD into the potential distribution on the surface of the …

Intraocular Pressure Sensing And Control For Glaucoma Research, Simon Antonio Bello

USF Tampa Graduate Theses and Dissertations

Animal models of ocular hypertension are important for glaucoma research but come with experimental costs. Available methods of intraocular pressure (IOP) elevation are not always successful, the amplitude and time course of IOP changes are unpredictable and irreversible, and IOP measurement by tonometry is laborious. This dissertation focuses on the development and implementation of two novel systems for monitoring and controlling IOP without these limitations. The first device consists of a cannula implanted in the anterior chamber of the eye, a pressure sensor that continually measures IOP, and a bidirectional pump driven by control circuitry that can infuse or withdraw …

Analysis And Processing Of Human Electroretinogram, Abdulrahman Mohammad Alaql

USF Tampa Graduate Theses and Dissertations

Electroretinagram (ERG) is the recording of electrical activity of retinal cells elicited by light stimulation, which has been widely used to help diagnose different types of retinal dysfunctions. The ERG response signal is a short non-stationary signal that contains overlapping components. Different Digital Signal Processing (DSP) techniques are investigated using MATLAB to study the time-frequency responses of the ERG signal such as Short Time Fourier Transform (STFT), Continuous Wavelet Transform (CWT) and Discrete Wavelet Transform (DWT). The Photopic ERG signal was processed and analyzed in this thesis and the results of each technique have been investigated in detail. The Photopic …

Biomaterial Testing Methodology For Long-Term In Vivo Applications: Silicon Carbide Corrosion Resistance, Biocompatibility And Hemocompatibility, Maysam Nezafati

USF Tampa Graduate Theses and Dissertations

Biomedical devices that function in-vivo offer a tremendous promise to improve the quality of life for many who suffer from disease and trauma. The most important consideration for these devices is that they interact with the physiological environment as designed without initiating a deleterious inflammatory response. ISO 10993 outlines the current international guideline for investigating the biocompatibility of such devices. Numerous groups report the use of ISO 10993 as the basis for their experimental evaluation of candidate materials for neuroprosthetics, as well as other biomedical devices, however most of these reports fail to completely comply with the standard. This leads …

Sic For Advanced Biological Applications, Joseph Register

USF Tampa Graduate Theses and Dissertations

Silicon carbide (SiC) has been used for centuries as an industrial abrasive and has been

actively researched since the 1960's as a robust material for power electronic applications.

Despite being the first semiconductor to emit blue light in 1907, it has only recently been

discovered that the material has crucial properties ideal for long-term, implantable biomedical

devices. This is due to the fact that the material offers superior biocompatibility and

hemocompatibility while providing rigid mechanical and chemical stability. In addition, the material

is a wide-bandgap semiconductor that can be used for optoelectronics, light delivery, and optical

sensors, which is the …

A Biocompatible Sic Rf Antenna For In-Vivo Sensing Applications, Shamima Afroz

USF Tampa Graduate Theses and Dissertations

A continuous glucose sensor employing radio frequency (RF) signals is presented using the biocompatible material Silicon Carbide (SiC). Unlike biosensors that require direct contact with interstitial fluids to trigger chemical reactions to operate, this biocompatible SiC sensor does not require a direct interface. The sensing mechanism for this SiC sensor is based upon a shift in resonant frequency, as a function of change in glucose levels, which electrically manifests itself as a change in blood permittivity and

conductivity. For in vivo applications the antenna sensor needs to operate inside the body environment, and it has been found that the best …

Vapor-Liquid-Solid(Vls) Grown Silica (Siox) Nanowires As The Interface For Biorecognition Molecules In Biosensors, Eduardo Murphy-Pérez

USF Tampa Graduate Theses and Dissertations

SiOx nanowires grown through the VLS mechanism were electrophoretically deposited on top of Au electrodes. GOx was immobilized using APTES and the EDC-NHS chemistry. Cyclic Voltammetry was used as the method to characterize the electrodes through their processing steps, and CV was also used to detect glucose in a PBS based solution. Ferro-Ferri Cyanide couple was used as the mediator.

Myoglobin Detection On Sic: Immunosensor Development For Myocardial Infarction, Alexandra Oliveros Villalba

USF Tampa Graduate Theses and Dissertations

Silicon carbide (SiC) has been around for more than 100 years as an industrial material and has found wide and varied applications because of its unique electrical and thermal properties. In recent years there has been increased attention on SiC as a viable material for biomedical applications. Among these applications are those where SiC is used as a substrate material for biosensors and biotransducers, taking advantage of its surface chemical, tribological and electrical properties.

In this work we have used the proven bio- and hema-compatibility of SiC to develop a viable biorecognition interface using SiC as the substrate material for …

Optimization Of Bio-Impedance Sensor For Enhanced Detection And Characterization Of Adherent Cells, Dorielle T. Price

USF Tampa Graduate Theses and Dissertations

This research focuses on the detection and characterization of cells using

impedance-based techniques to understand the behavior and response of cells to internal/environmental changes. In combination with impedimetric sensing techniques, the biosensors in this work allow rapid, label-free, quantitative measurements and are very sensitive to changes in environment and cell morphology. The biosensor design and measurement setup is optimized to detect and differentiate cancer cells and healthy (normal) cells. The outcome of this work will provide a foundation for enhanced 3-dimensional tumor analysis and characterization; thus creating an avenue for earlier cancer detection and reduced healthcare costs.

The magnitude of …

Development Of A Bi-Directional Electronics Platform For Advanced Neural Applications, Luca Abbati

USF Tampa Graduate Theses and Dissertations

This work presents a high-voltage, high-precision bi-directional multi-channel system capable of stimulating neural activity through bi-phasic pulses of amplitude up to ∓50 V while recording very low-voltage responses as low as tens of microvolts. Most of the systems reported from the scientific community possess at least one of the following common limitations: low stimulation voltages, low gain capabilities, or insufficient bandwidth to acquire a wide range of different neural activities.

While systems can be found that present remarkable capabilities in one or more specific areas, a versatile system that performs over all these aspects is missing. Moreover, as many novel …

Guiding Electric Fields For Electroporation Applications, Jose Rey

USF Tampa Graduate Theses and Dissertations

Electroporation is the critical step in an electric field mediated drug or gene delivery protocol. Electroporation based protocols have been successfully demonstrated in cancer clinical trials, however, its impact in other applications is still under investigation. A significant roadblock to long term functioning of implantable biosensors in vivo is the tissue reaction in the form of fibrous encapsulation that results in reduced transport to the sensing element of the biosensor. In vivo gene electroporation has a great potential as a means to modify the transport properties of tissues in the proximity of the sensing element of implantable biosensors.

This dissertation …

Atrial Fibrillation Signal Analysis, Raja Sarath Chandra Prasad Vaizurs

USF Tampa Graduate Theses and Dissertations

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia encountered in clinical practice and is associated with an increased mortality and morbidity. Identification of the sources of AF has been a goal of researchers for over 20 years. Current treatment procedures such as Cardio version, Radio Frequency Ablation, and multiple drugs have reduced the incidence of AF. Nevertheless, the success rate of these treatments is only 35-40% of the AF patients as they have limited effect in maintaining the patient in normal sinus rhythm. The problem stems from the fact that there are no methods developed to analyze …