Biomedical Commons^™

Brain Tumor Progression Assessment Using Multiple Mri Volumes, Yufei Shen

Electrical & Computer Engineering Theses & Dissertations

Predicting and assessing tumor progression is important in brain tumor treatment. We attempt to use machine learning techniques to achieve consistency in assessing brain tumor progression. This thesis presents a prediction method of brain tumor progression by exploring a large MR database, which contains two patients ' complete records covering all their visits in the past two years. All ten MRI series, namely, apparent diffusion coefficient (ADC) , diffusion tensor imaging (DTI) , fractional anisotropy (FA), fluid attenuated inversion recovery (FLAIR), max eigenvalue (MAX), mid eigenvalue (MID), min eigenvalue (MIN) , post-contrast T₁-weighted, T₁- weighted, and …

Effects Of Low-Temperature Atmospheric Pressure Plasma On Streptococcus Mutans, Margaret Farrer Lemaster

Dental Hygiene Theses & Dissertations

The recent emergence of low temperature atmospheric pressure plasma (LTAPP) technology has led researchers to explore biomedical applications. The present study set out to determine if LTAPP has the ability to inactivate dental caries causing bacteria, specifically Streptococcus mutans. Methods: A total of 90 samples were processed. Seventy-two samples of S. mutans at 1: 100 dilution in BHI broth were exposed to LTAPP for various time intervals (60, 120, 180, 300 seconds). Eighteen control samples were plated but not exposed to LTAPP. Samples were plated on Mi tis salivarius (MS) agar and incubated 48 hours at 37° C. Colony …

A Hybrid Biofuel Cell Based On Electrooxidation Of Glucose Using Ultra-Small Silicon Nanoparticles, Yongki Choi, Gang Wang, Munir H. Nayfeh, Siu-Tung Yau

Electrical and Computer Engineering Faculty Publications

The ultra-small silicon nanoparticle was shown to be an electrocatalyst for the electrooxidation of glucose. The oxidation appeared to be a first order reaction which involves the transfer of 1 electron. The oxidation potential showed a low onset of −0.4V vs. Ag/AgCl (−0.62V vs. RHE). The particle was used as the anode catalyst of a prototype hybrid biofuel cell, which operated on glucose and hydrogen peroxide. The output power of the hybrid cell showed a dependence on the enzymes used as the cathode catalyst. The power density was optimized to 3.7μW/cm² when horseradish peroxidase was …

Lifetime Estimation Of Wireless Body Area Sensor Network For Patient Health Monitoring, Frank Agyei-Ntim

Electronic Theses and Dissertations

Wireless Body Area Sensor Networks (WBASN) is an emerging technology which utilizes wireless sensors to implement real-time wearable health monitoring of patients to enhance independent living. These sensors can be worn externally to monitor multiple bio-parameters (such as blood oxygen saturation (SpO2), blood pressure and heart activity) of multiple patients at a central location in the hospital.

In health monitoring, the loss of critical or emergency information is a serious issue so there is a concern for quality of service which needs to be addressed. It is important to have an estimate of the time the first node will fail …

Time-Frequency Analysis Of Intracardiac Electrogram, Erik Brockman

Master's Theses

The Cardiac Rhythm Management Division of St. Jude Medical specializes in the development of implantable cardioverter defibrillators that improve the quality of life for patients diagnosed with a variety of cardiac arrhythmias, especially for patients prone to sudden cardiac death. With the goal to improve detection of cardiac arrhythmias, this study explored the value in time-frequency analysis of intracardiac electrogram in four steps. The first two steps characterized, in the frequency domain, the waveforms that construct the cardiac cycle. The third step developed a new algorithm that putatively provides the least computationally expensive way to identifying cardiac waveforms in the …

Computational Modeling Of The Internal Structure In The Breast, Jordan Greenlee

Electrical Engineering Undergraduate Honors Theses

Many researchers who are using microwave modality in the area of breast cancer detection employ oversimplified models of the internal structure of the breast. Use of engineered or biologically inaccurate models could render inaccurate results. Therefore, a mathematical biological model is implemented in this work and aims to bridge the gap between biologists and engineers. The results of the proposed breast duct model show that older women have smaller breast ducts leading to less dense breasts, which is in agreement with medical knowledge. Also, younger women have larger breast ducts leading to more dense breasts which are consistent with the …

Low Voltage, Low Power, Bulk-Driven Amplifier, Shama Huda

Electrical Engineering Undergraduate Honors Theses

The importance of low voltage and low powered electronics is increasing with advances in medical electronics. This branch of electronics specifically requires low voltage and low power to make efficient innovative medical equipment. Low power electronics are also desirable because it conserves energy and power. This paper proposes a design of a differential in - differential our amplifier that uses a bulk-driven differential pair for the input pair. In addition, it also used bulk-driven current mirrors for the tail current sink and the active loads. The bulkdriven technique helps to achieve the low voltage design. 90nm CMOS technology was considered …

Preliminary Study Based On The Ddscat Software To Explore Increasing The Contrast Of Breast Tumors For Microwave Imaging, Rachel Megee

Electrical Engineering Undergraduate Honors Theses

Microwave technology is being researched for its capabilities to detect breast tumors less painfully and at earlier stages. It is necessary to have a large contrast between cancerous and healthy tissue when the microwaves are reflected off the breast tissue. To model the increasing contrast between cancerous breast tissue and healthy breast tissue, the DDSCAT code is investigated for its capabilities and analyzed for its accuracy in scattering calculations. The DDSCAT is used to model homogenous and inhomogeneous targets. Simulations of the scattering field by the homogeneous and inhomogeneous targets are conducted and compared to Mie theory calculations for accuracy. …

Analysis Of Electroencephalogram Signals For The Identification Of Mental Tasks, My Thy Thi Tran

Electrical & Computer Engineering Theses & Dissertations

Electroencephalogram (EEG) signals can be used for implicit communication such as to control robots or medical equipment by brain activity or to detect an individual's intentions of committing premeditated crimes. An EEG based brain-computer interface allows paralyzed patients to express their thoughts. However, biological and technical artifacts heavily interfered with EEG signals due to blinking of the eyes, muscle activities and line noise. Sometimes the noise interference due to signal artifacts becomes more prominent than the information content. This thesis investigates novel feature extraction methodologies in EEG signals to represent different thought processes and employs neural network-based pattern classification techniques …

System Architecture For An Intelligent Implantable Bio-Telemetry Device, Karthik Kumar Nattamai Kumaresan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biotelemetry has long been used for environmental and life science research to study animal populations and behavior. The use of implantable bio-telemetric techniques makes it possible to record and study physiological variables during long-term experiments with a minimum disturbance to the animal. Fully implantable telemetric techniques greatly reduce the risk of infection associated with leads and catheters protruding from the skin. In this research the design and implementation of a completely programmable bio-implantable digital system which can measure two physiological signals extended over a period of time is considered. The proposed system consists of a standalone implantable transmitter unit and …

Application Of Sensor Fusion To Human Locomotor System, John Kweku Avor

Open Access Theses & Dissertations

This research study proposes a multi-sensor data fusion technique to determine the complex interactions between the sensory, muscular and mechanical components of the human locomotor systems (neuromechanics). The object in this work is to demonstrate the viability in using inertial sensors for accurate gait phase determination and to present the acceleration effect specific body segment contributes in order to establish a functional gait. The current method used in determining gait phases consist of combining ground reaction force and angular data, this method is time consuming and cannot be totally reliable. We found out that gait phases can be determined distinctively …

Optimizing Computer-Aided Colonic Polyp Detection For Ct Colonography By Evolving The Pareto Front, Jiang Li, Adam Huang, Jack Tao, Jiamin Liu, Robert L. Van Uitert, Nicholas Petrick, Ronald Summers

Electrical & Computer Engineering Faculty Publications

A multiobjective genetic algorithm is designed to optimize a computer-aided detection (CAD) system for identifying colonic polyps. Colonic polyps appear as elliptical protrusions on the inner surface of the colon. Curvature-based features for colonic polyp detection have proved to be successful in several CT colonography (CTC) CAD systems. Our CTC CAD program uses a sequential classifier to form initial polyp detections on the colon surface. The classifier utilizes a set of thresholds on curvature-based features to cluster suspicious colon surface regions into polyp candidates. The thresholds were previously chosen experimentally by using feature histograms. The chosen thresholds were effective for …

Identification Of Human Gait Using Genetic Algorithm Tuned Fuzzy Logic, Abdallah Abdel-Rahman Hassan Mahmoud

Open Access Theses & Dissertations

Data mining is concerned with the discovery of useful hidden information in large databases. Classification is a data mining task producing rules in which a set of attributes in data predict the value of a class attribute. Classifiers usually produce a large number of rules, most of which are not interesting to the user. Rule interestingness is a decisive factor. However, evaluating rule interestingness is challenging as it involves both objective (data-driven) and subjective (user-driven) aspects.

In this research, a fuzzy genetic algorithm is proposed to discover classification rules that are both accurate and interesting. Continuous attributes are fuzzified so …

Exploring Poly(Ethylene Glycol) As A Suitable Material For Peripheral Nerve Regeneration Scaffolds Manufactured By Stereolithography, Nubia Zuverza

Open Access Theses & Dissertations

One of the challenges in tissue engineering is to have spatial and temporal control over the biological elements within a scaffold used to guide regeneration for example of transected nerves. Some of the physical and chemical characteristics to regulate include incorporation of bioactive domains and release of chemical signals. This study presents the use of stereolithography (SL) to incorporate localized domains for cell adhesion in addition to include releasable nerve growth factor (NGF) in the process of building poly(ethylene glycol)diacrylate (PEGda) hydrogel scaffolds. Besides providing sites for cell attachment, an ideal nerve guidance conduit (NGC) should be able to release …

Parameter Optimization For Image Denoising Based On Block Matching And 3d Collaborative Filtering, Ramu Pedada, Emin Kugu, Jiang Li, Zhanfeng Yue, Yuzhong Shen, Josien P.W. Pluim (Ed.), Benoit M. Dawant (Ed.)

Electrical & Computer Engineering Faculty Publications

Clinical MRI images are generally corrupted by random noise during acquisition with blurred subtle structure features. Many denoising methods have been proposed to remove noise from corrupted images at the expense of distorted structure features. Therefore, there is always compromise between removing noise and preserving structure information for denoising methods. For a specific denoising method, it is crucial to tune it so that the best tradeoff can be obtained. In this paper, we define several cost functions to assess the quality of noise removal and that of structure information preserved in the denoised image. Strength Pareto Evolutionary Algorithm 2 (SPEA2) …

Automatic Diagnosis For Prostate Cancer Using Run-Length Matrix Method, Xiaoyan Sun, Shao-Hui Chuang, Jiang Li, Frederic Mckenzie, Nico Karssemeijer (Ed.), Maryellen L. Giger (Ed.)

Electrical & Computer Engineering Faculty Publications

Prostate cancer is the most common type of cancer and the second leading cause of cancer death among men in US¹. Quantitative assessment of prostate histology provides potential automatic classification of prostate lesions and prediction of response to therapy. Traditionally, prostate cancer diagnosis is made by the analysis of prostate-specific antigen (PSA) levels and histopathological images of biopsy samples under microscopes. In this application, we utilize a texture analysis method based on the run-length matrix for identifying tissue abnormalities in prostate histology. A tissue sample was collected from a radical prostatectomy, H&E fixed, and assessed by a pathologist …

Biomarker Identification For Prostate Cancer Using An Efficient Feature Selection Algorithm, Vamsi Krishnam Raju Mantena

Electrical & Computer Engineering Theses & Dissertations

In recent years, there has been an increased interest in using protein mass spectrometry to identify biomarkers that discriminate diseased from healthy individuals. A biomarker is a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathological processes, or pharmacological responses to a therapeutic intervention. Identifying biomarkers will be an important step towards disease characterization and patient management. One challenge of biomarker identification is how to handle the high dimensional mass spectral data. In this thesis, we applied an efficient feature selection algorithm to mass spectrometry data obtained from prostate tissue samples to identify prostate …

Microwave Dielectroscopy Of Breast Tissue Phantoms In The 5.8-40 Ghz Range, Binh Tran

Electrical Engineering Undergraduate Honors Theses

Based on the high contrast in dielectric properties between the low-water-contain sample and the high-water-content one, we can determine whether the tissue sample is cancerous or normal. In order to make the measurement repeatable and convenient, some phantom materials, which have the same dielectric properties of human tissues, have been prepared. These phantom tissues are made from gelatin, water with honey syrup and Sodium Chloride (NaCl). In this project, we are going to measure and compare the dielectric properties of different types of phantom tissues by using focused beam antennas. The purpose of this project is to perform a systematic …

Dna Comparison Chip: Circuit Design And Evaluation, Tushar Bajaj

Electrical Engineering Undergraduate Honors Theses

The purpose of this project was to: First, design a microchip that is capable of comparing strings of DNA sequences. Second, evaluate the functioning of such a microchip and how it can implemented in various real world applications. Physically, this microchip will act as an attachment to any computer. The computer will send two strings of DNA sequences-one library string and one pattern string-and the chip will output the number of matches that exist between the two strings (at a given position of the pattern string with respect to the library string). The circuit design is based on a 600 …

An Approach To Identifying The Biomechanical Differences Between Intercostal Cartilage In Subjects With Pectus Excavatum And Normals In Vivo: Reconstruction And Ct Registration, Zhenzhen Yan

Electrical & Computer Engineering Theses & Dissertations

Pectus excavatum (PE) is a congenital chest wall deformity affecting the ribs and sternum and exhibiting a concave appearance in the anterior chest wall. In this thesis, we describe a study to investigate in vivo differences in the pectus excavatum rib cage and outline steps using normals and pectus patients data in developing models and methods to be used in carrying out the study. We propose methods to develop reconstructed models in order to enable proper registration between data collection points (DCPs) on the 3D CT rib cage model and CT skin surface model and registration between CT surrogate models …

Fluorescent Si Nanoparticle-Based Electrode For Sensing Biomedical Substances, Gang Wang, Siu-Tung Yau, Kevin Mantey, Munir H. Nayfeh

Electrical and Computer Engineering Faculty Publications

We have been studying the miniaturization of silicon crystals and the transition from the solid state to the atomistic state. We demonstrated the existence of “sweet spots” in cluster size in the range 1–3nm that have enhanced chemical, structural, and photo stability. The particles are produced by an electrochemical etching process as dispersion in liquid, and they are reconstituted in films, patterns, alloys, or spread on chips to produce super chips. Unlike bulk, these Si nanoparticle configurations have a spectacular ability to glow in distinct RGB colors. In this paper we describe an electrode sensor built by decorating metal or …

Mems Transducer For Hearing Aid Device, Houwen Tang

Electronic Theses and Dissertations

A study of implantable middle ear MEMS piezoelectric transducer for hearing aids was developed. The physical vibration deflection at the tip of the transducer is simulated using finite element method. Further, a study of thermoelastic damping effect of four designed MEMS mirrors used as resonators is presented. An optical measurement system based on Mach-Zehnder interferometer is

Microfluidic Devices For Terahertz Spectroscopy Of Biomolecules, P. A. George, W. Hui, F. Rana, Benjamin G. Hawkins, A. E. Smith, B. J. Kirby

Faculty Publications

We demonstrate microfluidic devices for terahertz spectroscopy of biomolecules in aqueous solutions. The devices are fabricated out of a plastic material that is both mechanically rigid and optically transparent with near-zero dispersion in the terahertz frequency range. Using a low-power terahertz time-domain spectrometer, we experimentally measure the absorption spectra of the vibrational modes of bovine serum albumin from 0.5–2.5 THz and find good agreement with previously reported data obtained using large-volume solutions and a high-power free-electron laser. Our results demonstrate the feasibility of performing high sensitivity terahertz spectroscopy of biomolecules in aqueous solutions with detectable molecular quantities as small as …

Stereolithography Of Poly(Ethylene Glycol) Hydrogels With Application In Tissue Engineering As Peripheral Nerve Regeneration Scaffolds, Karina Arcaute

Open Access Theses & Dissertations

In recent years, rapid prototyping (RP) technologies initially developed to create prototypes prior to production for the automotive, aerospace, and other industries, have found applications in tissue engineering (TE). Several different RP technologies are being used to fabricate biocompatible 3D structures with controlled micro- and macro-scale characteristics. The focus of this research was to explore the capabilities of the RP technology, stereolithography (SL), for creating complex, 3D scaffolds with applications in TE using a photocrosslinkable biopolymer, poly(ethylene glycol) (PEG). The primary objective was to create an implantable multi-lumen nerve guidance conduit (NGC) for the regeneration of peripheral nerves.

Studies of …

An Efficient Algorithm For Biomarker Identification, Jiang Li, Rick Mckenzie, Lisa Cazares, Richard Drake, John Semmens

Electrical & Computer Engineering Faculty Publications

No abstract provided.

Assessment Of Human Muscle Fatigue From Surface Emg Signals Recorded During Isometric Voluntary Contractions By Using A Cosine Modulated Filter Bank, Cristhian Mauricio Potes

Open Access Theses & Dissertations

Human muscle fatigue involves both a decrease in the frequency and increase in the amplitude of a surface electromyographic (EMG) signal. Muscle fatigue is also related to a decrease of the force impeding to reach the same initial level of the maximum voluntary contraction (MVC). To determine muscle fatigue indices, a method is proposed by decomposing a surface EMG signal into 32-subbands. This decomposition was attained by using a cosine modulated filter bank. The

surface EMG signals analyzed during this research were recorded during isometric voluntary contractions. Both the instantaneous mean frequency (IMF) and the instantaneous amplitude (IA) are estimated …

Microfabrication Of An Optical Chamber For Exposing Living Cells To Pulsed Electric Fields, Saleh Sheikh

Electrical & Computer Engineering Theses & Dissertations

I have fabricated a chamber which enables the application of Nanosecond Pulsed Electric Fields (nsPEFs) to living cells while monitoring their real time fluorescence with an inverted microscope. The No. I thickness (150µm nominal) coverslip glass substrate used for fabrication allows the use of high numerical aperture oil immersion objectives for imaging intracellular organelles. Electrodes are fabricated by first evaporating a chromium adhesion layer, followed by a nickel seed layer. Subsequently, an ultra-thick positive photoresist is applied and patterned to create a 30µm thick electroplating mold. The electrodes are then electrodeposited into the mold from a nickel sulfamate plating bath. …

Shaken Baby Syndrome: Retinal Hemorrhaging. A Biomechanical Approach To Understanding The Mechanism Of Causation, Steven Alex Hans

Mechanical & Aerospace Engineering Theses & Dissertations

Shaken Baby Syndrome (SBS) is a form of abuse where typically an infant, age six months or less, is held and shaken. There may or may not be direct impact associated with this action. Further, there is very little agreement on the actual mechanism of SBS. Clinical studies are limited in showing the exact mechanism of injury and only offer postulations and qualitative descriptions. SBS has received much attention in the media, has resulted in a great deal of litigation and can be the source of unfounded accusations. Therefore, it is necessary to try to quantify the forces that may …

Preserved Enzymatic Activity Of Glucose Oxidase Immobilized On Unmodified Electrodes For Glucose Detection, Gang Wang, Ngee Mei Thai, Siu-Tung Yau

Electrical and Computer Engineering Faculty Publications

Glucose sensing electrodes have been realized by immobilizing glucose oxidase (GOx) on unmodified edge plane of highly oriented pyrolytic graphite (epHOPG) and the native oxide of heavily doped silicon (SiO₂/Si). Both kinds of electrode show direct interfacial electron transfer due to the redox process of the immobilized GOx. The measured formal potential of the redox process agrees with that of the native enzyme, suggesting that the immobilized GOx has retained its enzymatic activity. The electron transfer rates of the GOx immobilized electrode are 2s⁻¹ for GOx/epHOPG electrode and 7.9s⁻¹ for GOx/SiO₂/Si electrode, which …

Simulation And Modeling Of Nerve Impulse Propagation And Its Blockage By External Electrical Stimulation, Nidhi Nahar

Electrical & Computer Engineering Theses & Dissertations

The electric nature of biological tissues permits the transmission of signals for information and for control and is, therefore, of vital importance for life. The latest scientific achievements and nanoscale probing techniques now allow scientists to research at the subcellular level by measuring the electric current flows through a single ion channel of the cell membrane with the patch-clamp method. With the latter approach, the effects of electrical stimulation can be quantified, understood, and applied to molecular biology and the development of medical diagnostic and therapeutic methods.

In this thesis, the Hodgkin-Huxley approach for unmyelinated fibers, coupled with a transmission …