Biomedical Commons^™

Development And Applications Of Novel Fluorescent Molecular Probe Strategies, Dolonchampa Maji

McKelvey School of Engineering Graduate Student Theses & Dissertations

Optical imaging and spectroscopy technologies offer the ability to provide structural and functional information in a fast, low-cost, ionizing radiation free, highly sensitive and high throughput fashion. The diverse contrast mechanisms and complementary imaging platforms form the foundation for the application of optical imaging in pre-clinical studies of pathophysiological development as well as direct clinical application as a tool for diagnosis and therapy. Fluorescence imaging techniques have been one of the most rapidly adopted methods in biology and biomedicine. Visualization of biological processes and pathologic conditions at the cellular and tissue levels largely relies on the use of exogenous fluorophores …

Multidataset Independent Subspace Analysis: A Framework For Analysis Of Multimodal, Multi-Subject Brain Imaging Data, Rogers F. Silva

Electrical and Computer Engineering ETDs

Mental illnesses are serious disorders of the brain that have devastating effects on individuals and society. In addition to their disabling and impairing effects, mental illnesses have deep social and economical implications, accounting for an estimated loss of 12 billion working days and a care cost surge to $6 trillion a year by 2030. For diseases such as depression and anxiety, enhancing preventive programs and treatment accessibility, in combination with accurate early diagnosis and personalized treatments, are projected to result in a four-fold return on every dollar invested, a strategy that can drastically help curtail those losses. Notably, within the …

An Exact Analysis For Four-Order Acousto-Optic Bragg Diffraction Which Incorporates Both Incident Light Angle And Sound Frequency Dependencies, Adeyinka Sunday Ademola

Electrical Engineering Theses

This thesis extends the prior work which produced an exact solution to the four-order acousto-optic (AO) Bragg cell with assumed fixed center frequency and with exact Bragg angle incident light. The extension predicts the model that incorporates the dependencies of both the input angle of light and the sound frequency. Specifically, a generalized 4^th order linear differential equation (DE), is developed from a simultaneous analysis of four coupled AO system of DEs. Through standard methods, the characteristic roots, which requires solving a quartic equation, is produced. Subsequently, a derived system of homogeneous solutions, which absorbs the roots obtained using …

Development Of An Oxygen Saturation Monitoring System By Embedded Electronics, Manikandan Venkatesan Gomathy

Graduate Theses and Dissertations

Measuring Oxygenation of blood (SaO2) plays a vital role in patient’s health monitoring. This is often measured by pulse oximeter, which is standard measure during anesthesia, asthma, operative and post-operative recoveries. Despite all, monitoring Oxygen level is necessary for infants with respiratory problems, old people, and pregnant women and in other critical situations.

This paper discusses the process of calculating the level of oxygen in blood and heart-rate detection using a non-invasive photo plethysmography also called as pulsoximeter using the MSP430FG437 microcontroller (MCU). The probe uses infrared lights to measure and should be in physical contact with any peripheral points …

Estimation Of Localized Ideal Oximetry Sensor Lag Via Oxygen Desaturation-Disordered Breathing Event Cross-Correlation, Brian Snider, A Kain

Faculty Publications - Department of Electrical Engineering and Computer Science

In previous work, we attempted to identify events using sensor data from full-night polysomnography studies using a global 20-second oximetry sensor lag across all studies. However, we observed that oxygen desaturation onset trailed the corresponding human expert-labeled events by varying amounts of time, even within the same study. In this work, we estimate the localized ideal oximetry (SpO₂) sensor lag using the cross-correlation between the labeled disordered breathing event and the observed desaturation.

Silent Communication Device, Christopher Wayne Schutter

Master's Theses

Oral communication has constituted as a necessary aspect of how people interact with one another, but there are always situations where this form of communication can create distractions, irritation, or even danger. Take for example, a student in a laboratory who needs to communicate effectively with a lab partner without creating a distraction to those trying to work around said student or a soldier on a battlefield who needs to relay information effectively to his or her comrades without revealing his or her position to the enemy. It becomes apparent that people need a more exclusive form of communication in …

T1, T2, And Off-Resonance Mapping Using A Non-Linear Least-Squares Fit Of The Bssfp Signal, Meredith Taylor, Joseph Valentine, Steven Whitaker, Neal Bangerter

Biomedical Engineering Western Regional Conference

The mapping of MR relaxation times has found a broad variety of applications in the study of disease. Unfortunately, the gold standards for acquiring T₁ and T₂ maps require long scan times, and are therefore more suited to 2D acquisitions with limited slices. For reasonable scan times, resolution is limited making these scans less useful for showing fine morphological detail. A rapid 3D sequence at higher resolutions that could be used to provide both morphological detail and relaxation time maps would be particularly useful. We propose a technique with potential to provide simultaneous band-free 3D datasets and estimates …

Bssfp Elliptical Signal Model With Grappa Parallel Imaging, Grayson Tarbox, Joseph Valentine, Meredith Taylor, Neal Bangerter

Biomedical Engineering Western Regional Conference

In magnetic resonance imaging, balanced steady-state free precession acquisition using the elliptical signal model geometrical solution can be combined with a GRAPPA parallel imaging reconstruction that preserves phase information to shorten scan times.

Water Fat Separation With Multiple-Acquisition Bssfp Mri, Michael A. Mendoza 8232743, Joseph Valentine, Neal Bangerter

Biomedical Engineering Western Regional Conference

We present a technique that combines the advantages of bSSFP MRI with Dixon reconstruction in order to produce robust water fat separation with high SNR in a short imaging time, while simultaneously reducing banding artifacts that traditionally degrade image quality.

3d Printed Microfluidics, Hua Gong, Clayton Ramstedt, Adam T. Woolley, Gregory P. Nordin

Biomedical Engineering Western Regional Conference

3D printing for microfluidic (lab-on-a-chip) devices

Toward Improving Electrocardiogram (Ecg) Biometric Verification Using Mobile Sensors: A Two-Stage Classifier Approach, Robin Tan, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Electrocardiogram (ECG) signals sensed from mobile devices pertain the potential for biometric identity recognition applicable in remote access control systems where enhanced data security is demanding. In this study, we propose a new algorithm that consists of a two-stage classifier combining random forest and wavelet distance measure through a probabilistic threshold schema, to improve the effectiveness and robustness of a biometric recognition system using ECG data acquired from a biosensor integrated into mobile devices. The proposed algorithm is evaluated using a mixed dataset from 184 subjects under different health conditions. The proposed two-stage classifier achieves a total of 99.52% subject …

Enhanced Breast Cancer Classification With Automatic Thresholding Using Support Vector Machine And Harris Corner Detection, Mohammad Taheri

Electronic Theses and Dissertations

Image classification and extracting the characteristics of a tumor are the powerful tools in medical science. In case of breast cancer medical treatment, the breast cancer classification methods can be used to classify input images as benign and malignant classes for better diagnoses and earlier detection with breast tumors. However, classification process can be challenging because of the existence of noise in the images, and complicated structures of the image. Manual classification of the images is timeconsuming, and need to be done only by medical experts. Hence using an automated medical image classification tool is useful and necessary. In addition, …

Label-Free Raman Imaging To Monitor Breast Tumor Signatures, John Ciubuc

Open Access Theses & Dissertations

Methods built on Raman spectroscopy have shown major potential in describing and discriminating between malignant and benign specimens. Accurate, real-time medical diagnosis benefits in substantial improvements through this vibrational optical method. Not only is acquisition of data possible in milliseconds and analysis in minutes, Raman allows concurrent detection and monitoring of all biological components. Besides validating a significant Raman signature distinction between non-tumorigenic (MCF-10A) and tumorigenic (MCF-7) breast epithelial cells, this study reveals a label-free method to assess overexpression of epidermal growth factor receptors (EGFR) in tumor cells. EGFR overexpression sires Raman features associated with phosphorylated threonine and serine, and …

Production And Functionality Of Melanocytes For Use In 3d-Printed Pigment-Capable Skin Tissue, Corinne Nicole Wittmann

Open Access Theses & Dissertations

Skin grafts are used in a variety of medical procedures including burn treatment, skin cancer removal, chronic wound/ulcer treatment, skin infections and diseases, large wound closure and in elective plastic surgeries. Ideally, skin grafts are harvested directly from the patient. However, in some cases, direct harvesting of skin grafts is not possible. In these situations, an equivalent skin substitute obtained through another source is utilized. There will always be a greater risk of rejection in such cases and therefore is only intended to be a temporary treatment. A possible solution to lessen the risks and issues associated with skin grafts …

Process-Structure-Property Relationship In Magnesium-Based Biodegradable Alloy For Biomedical Applications, Pramanshu Trivedi

Open Access Theses & Dissertations

Magnesium alloys are considered to be the next generation of biomaterials because of their ability to degrade in the physiological environment. We elucidate here the impact of multiaxial forging of Mg-2Zn-2Gd alloy on grain refinement to sub-micron regime and relate the structure to mechanical properties and biological functionality. As-cast and annealed samples were multiaxial forged (MAF) for a total number of two passes with a true strain of ~2/pass. Considering that the microstructure governs the biological response of materials, we studied the constituents of the microstructure in conjunction with the mechanical behavior. The antimicrobial behavior in a Mg-2Zn-2Gd alloy with …

On Demand 3d Printed Hybrid Scaffolds For Tissue Engineering Applications, Ivan D. Hernandez

Open Access Theses & Dissertations

A composite 3D printed polymer scaffold with inbuilt porosity and filled with a hydrogel can provide an ideal support system for cell growth, proliferation, and vascularization. Therefore, a hybrid system of 3D printed polycaprolactone (PCL) scaffold and a hydroxyapatite-based hydrogel was developed for application in the reconstruction of bone defects, which are inherently difficult to repair without any guided therapies. In the present study, a 3D printed gyroid structure of PCL allowed the loading of a higher amount of hydrogel as compared to conventionally used 3D printed mesh structure of the same volume and strut thickness. The hydrogel was composed …

Redesign Of A Volume Adjustable Transtibial Prosthetic Socket, Samuel Terrazas Quezada

Open Access Theses & Dissertations

Recent research and development in prosthetics have aimed at improving socket designs and components to mimic more efficiently the human body. One such innovation is the Aperture Socket, a low-cost volume adjustable prosthetic socket. During the validation stage of its development, the Aperture Socket successfully demonstrated that it could compensate for volume changes, but various improvements on use and comfort were identified. This project develops and tests a redesign of the Aperture Socket previously developed for amputees in developing countries and subsequently patented and licensed to LIMBS International, Inc.

The first phase of this study was the creation of various …

Optimization Of Collagen Microneedle Using Taguchi Method, Abhilash Aditya

Open Access Theses & Dissertations

Research is conducted to create dissolving collagen microneedles and to optimize the parameters for close to perfect dimension microneedles. A collagen microneedle patch has been developed with a micro-manufacturing process (micro-molding process). The collagen microneedles, varying in length from 300 to 600-μm may reach different targeted layers of the skin depending on the application. As the microneedles penetrate the skin they dissolve, delivering collagen through the epidermis. Such addition of collagen directly to the dermis layers allows it to be absorbed, increasing skin's strength and resilience, since it is one of the natural components of the younger looking skin. This …

Properties And Optimization Of Respiratory Navigator Gating For Spiral Cine Dense Cardiac Mri, Sean Michael Hamlet

Theses and Dissertations--Electrical and Computer Engineering

Cardiac magnetic resonance (MR) imaging can non-invasively assess heart function. Displacement encoding with stimulated echoes (DENSE) is an advanced cardiac MR imaging technique that measures tissue displacement and can be used to quantify cardiac mechanics (e.g. strain and torsion). When combined with clinical risk factors, cardiac mechanics have been shown to be better predictors of mortality than traditional measures of heart function.

End-expiratory breath-holds are typically used to minimize respiratory motion artifacts. Unfortunately, requiring subjects to breath-hold introduces limitations with the duration of image acquisition and quality of data acquired, especially in patients with limited ability to hold their breath. …

Human Behavior Recognition Ssing Brain Lfp Signal In The Presence Of The Stimulation Pulse, Hosein M. Golshan, Adam O. Hebb, Sara J. Hanrahan, Joshua Nedrud, Mohammad H. Mahoor

Electrical and Computer Engineering: Graduate Student Scholarship

Design and Methodology

This study concentrates on human behavior classification task using local field potential (LFP) signals recorded from three subjects with Parkinson’s disease (PD). Existing approaches mainly employ the LFP signals acquired under the stimulation/off condition. In practical situations, however, it is necessary to design a classification method capable of recognizing different human activities under the stimulation/on condition, where the classification task is more complicated due to the artifacts imposed by the high amplitude stimulation pulse (~1-3volts). We utilize the time-frequency representation of the acquired LFPs in the Beta frequency range (~10-30Hz) to develop a feature space based on …

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

College of Graduate Studies: Theses & 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 implement …

Respiratory Prediction And Image Quality Improvement Of 4d Cone Beam Ct And Mri For Lung Tumor Treatments, Seonyeong Park

Theses and Dissertations

Identification of accurate tumor location and shape is highly important in lung cancer radiotherapy, to improve the treatment quality by reducing dose delivery errors. Because a lung tumor moves with the patient's respiration, breathing motion should be correctly analyzed and predicted during the treatment for prevention of tumor miss or undesirable treatment toxicity. Besides, in Image-Guided Radiation Therapy (IGRT), the tumor motion causes difficulties not only in delivering accurate dose, but also in assuring superior quality of imaging techniques such as four-dimensional (4D) Cone Beam Computed Tomography (CBCT) and 4D Magnetic Resonance Imaging (MRI). Specifically, 4D CBCT used in CBCT …

An Investigation Into Spike-Based Neuromorphic Approaches For Artificial Olfactory Systems, Anup Vanarse, Adam Osseiran, Alexander Rassau

Research outputs 2014 to 2021

The implementation of neuromorphic methods has delivered promising results for vision and auditory sensors. These methods focus on mimicking the neuro-biological architecture to generate and process spike-based information with minimal power consumption. With increasing interest in developing low-power and robust chemical sensors, the application of neuromorphic engineering concepts for electronic noses has provided an impetus for research focusing on improving these instruments. While conventional e-noses apply computationally expensive and power-consuming data-processing strategies, neuromorphic olfactory sensors implement the biological olfaction principles found in humans and insects to simplify the handling of multivariate sensory data by generating and processing spike-based information. Over …

A Wireless, Passive Sensor For Measuring Temperature At Orthopedic Implant Sites For Early Diagnosis Of Infections, Salil Sidharthan Karipott

Dissertations, Master's Theses and Master's Reports

Sensorized implants with embedded wireless, passive temperature sensors were developed for early detection of implant-associated infections. The operation principle of the sensor is based on the hypothesis that infections can lead to an increase in local temperature prior to the rise of body temperature. The sensor was an inductive capacitive (LC) circuit that has been used for monitoring of different parameters wirelessly, often in difficult to access environments. The sensor was fabricated on to an interference screw, which is used for tendon and ligament reconstruction surgeries. In this project, a sensorized interference screw was designed and fabricated by accommodating an …

Implantable Wireless Sensor Networks: Application To Measuring Temperature For In Vivo Detection Of Infections, Praharsh Madappaly Veetil

Dissertations, Master's Theses and Master's Reports

It is has been proven that infection in the body cause a local temperature increase due to localized inflammation. Therefore, a method to provide early diagnostic or long-term tracking of this infection will provide great benefits to patients with diabetic foot ulcers or sickle cell disease, and those receiving hemodialysis where they suffer from a weakened immune system. The goal of this project is to develop an implantable wireless temperature sensor based on a wireless sensor network system for monitoring infections in situ. The analog signals from the thermistors are digitized and wirelessly transmitted to a computer with an ez430-rf2500 …

Algorithm For Premature Ventricular Contraction Detection From A Subcutaneous Electrocardiogram Signal, Iris Lynn Shelly

Dissertations and Theses

Cardiac arrhythmias occur when the normal pattern of electrical signals in the heart breaks down. A premature ventricular contraction (PVC) is a common type of arrhythmia that occurs when a heartbeat originates from an ectopic focus within the ventricles rather than from the sinus node in the right atrium. This and other arrhythmias are often diagnosed with the help of an electrocardiogram, or ECG, which records the electrical activity of the heart using electrodes placed on the skin. In an ECG signal, a PVC is characterized by both timing and morphological differences from a normal sinus beat.

An implantable cardiac …

An Emg-Based Patient Monitoring System Using Zynq Soc Device, Farhad Fallahlalehzari

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis describes the design, development, and testing of an EMG-based patient monitoring system using the Zynq device. Zynq is a system on chip device designed by Xilinx which consists of an ARM dual cortex-A9 processor as well as an FPGA integrated into one chip. This work also analyzes the performance of image-processing algorithms on this system and compares that performance to more traditional PC-based systems. Image processing algorithms, such as Sobel edge detection, dilation and erosion, could be used in conjunction with a camera for the patient monitoring purposes. These algorithms often perform sub-optimally on processors because of their …

Radiation Therapy And Dosing Material Transport Methodology, Robert O'Brien

UNLV Theses, Dissertations, Professional Papers, and Capstones

A technique is examined here that utilizes high energy beta decays from a short lived radioisotope to treat medical conditions such as shallow cancerous lesions. A major benefit of beta particle interaction in tissue is a fixed penetration depth for the charged particle, with dose limited to the ultimate range of the beta particle. This method improves on some current techniques of radioactive brachytherapy, where "seeds" are placed inside patients through temporary or permanent implantation in order to kill cancerous cells or inhibit growth of tissue. The use of low energy gamma-rays is the most common method of treatment currently …

The Effects Of Cryopreservation On Human Dental Pulp-Derived Mesenchymal Stem Cells, Allison Elaine Tomlin

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many studies have demonstrated clinical applications for the use of dental pulp stem cells (DPSC) for the treatment of various conditions. This has driven medical and scientific interest in the collection, isolation and banking of DPSC tissues for research into these potential therapies. Few studies to date have evaluated the viability of DPSC following long-term cryopreservation. The purpose of this study is to evaluate the effects of cryopreservation on dental pulp-derived stem cells (DPSC) viability over a period of three years. Dental pulp-derived stem cells were isolated and cultured from thirty-one healthy teeth. DPSC isolates were assessed for doubling-time and …

Approaches For Capturing Time-Varying Functional Network Connectivity With Application To Normative Development And Mental Illness, Barnaly Rashid

Electrical and Computer Engineering ETDs

Since the beginning of medical science, the human brain has remained an unsolved puzzle; an illusive organ that controls everything- from breathing to heartbeats, from emotion to anger, and more. With the power of advanced neuroimaging techniques, scientists have now started to solve this nearly impossible puzzle, piece by piece. Over the past decade, various in vivo techniques, including functional magnetic resonance imaging (fMRI), have been increasingly used to understand brain functions. fMRI is extensively being used to facilitate the identification of various neuropsychological disorders such as schizophrenia (SZ), bipolar disorder (BP) and autism spectrum disorder (ASD). These disorders are …