Biomedical Engineering and Bioengineering Commons^™

Magnetic Resonance Imaging Compatible Remote Catheter Navigation System, Mohammad Ali Tavallaei

Electronic Thesis and Dissertation Repository

Many vascular and cardiac diseases are diagnosed and treated using a medical technique known as percutaneous transluminal catheter intervention (PTC). In PTC, the interventionalist inserts a catheter into the vasculature, and using the vessel as the guiding passageway, the catheter is navigated to desired anatomical targets where it would be used for various purposes such as catheter ablation for the treatment/management of cardiac arrhythmias. The catheterization procedure is conventionally guided with x-ray fluoroscopic imaging and more recently, but rarely, with Magnetic Resonance Imaging (MRI). X-ray imaging irradiates the patient directly during the procedure, and the staff and interventionalists indirectly through …

Diamond Mems Biosensors: Development And Applications, Wenli Zhang

Doctoral Dissertations

This research focuses on the development a dielectrophoresis-enhanced microfluidic impedance biosensor (DEP-e-MIB) to enable fast response, real-time, label-free, and highly sensitive sensor for bacterial detection in clinical sample. The proposed design consists of application of dielectrophoresis (DEP) across a microfluidic channel to one of the impedance spectroscopy electrodes in order to improve the existent bacterial detection limits with impedance spectroscopy. In order to realize such a design, choice of electrode material with a wide electrochemical potential window for water is very important. Conventional electrode material, such as gold, are typically insulated for the application of DEP, and they fail when …

Device, Method, And Algorithm To Assess Changes In Cardiac Output Via Intracardiac Impedance Monitoring, Geoffrey Fredrick Schau

Dissertations and Theses

Cardiac output, the volume of blood pumped by the heart over time, is a powerful clinical metric used by physicians to assess overall cardiac health and patient well-being. However, current cardiac output estimation methods are typically invasive, time-consuming, expensive, or some combination of all three. Patients that receive artificial cardiac pacemaker devices are particularly susceptible to cardiac dysfunction and often require long-term cardiac monitoring support.

This thesis proposes a novel cardiac output monitoring solution which leverages an implantable intracardiac medical device. The principles of traditional impedance cardiography, an established cardiac output monitoring technique in practice for over fifty years, have …

Exploration Of Stimulus Current Energy Reduction And Bifurcation Dynamics In Conductance-Based Neuron Models Using Optimal Control Theory, Michael E. Ellinger

Dissertations

Hodgkin-Huxley type conductance-based models can simulate the effect of time-varying injected stimulus currents on the neuron membrane voltage. The dynamics simulated by these model types enables investigation of the biophysical basis of neuronal activity which is fundamental to higher level function. Broadened understanding the basis of nervous system function could lead to development of effective treatment for related diseases, disorders, and the effects of trauma. In this dissertation, optimal control is used with conductance-based neuron models to develop a "Reduced Energy Input Stimulus Discovery Method." Within the method, an objective function balances two competing criteria: tracking a reference membrane voltage …

Design And Fabrication Techniques Of Devices For Embedded Power Active Contact Lens, Errol Heradio Leon

Master's Theses

This thesis designed and fabricated various devices that were interfaced to an IC for an active contact lens that notifies the user of an event by detection of an external wireless signal. The contact lens consisted of an embedded antenna providing communication with a 2.4GHz system, as well as inductive charging at an operating frequency of 13.56 MHz. The lens utilized a CBC005 5µAh thin film battery by Cymbet and a manufactured graphene super capacitor as a power source. The custom integrated circuit (IC) was designed using the On Semiconductor CMOS C5 0.6 µm process to manage …

Characterization Of Two Vernier-Tuned Distributed Bragg Reflector (Vt-Dbr) Lasers Used In Swept Source Optical Coherence Tomography (Ss-Oct), Greg M. Bergdoll

Master's Theses

Insight Photonic Solutions Inc. has continued to develop their patented VT-DBR laser design; these wavelength tunable lasers promise marked image-quality and acquisition time improvements in SS-OCT applications.

To be well suited for SS-OCT, tunable lasers must be capable of producing a highly linear wavelength sweep across a tuning range well-matched to the medium being imaged; many different tunable lasers used in SS-OCT are compared to identify the optimal solution.

This work electrically and spectrally characterizes two completely new all-semiconductor VT-DBR designs to compare, as well. The Neptune VT-DBR, an O-band laser, operates around the 1310 nm range and is a …

Mobile Health Sensing With Smart Phones, Abby Logan Wise

Electrical Engineering Undergraduate Honors Theses

Depression is a serious mental condition affecting many Americans and people across the world. Postpartum depression is a form of depression affecting women who have recently gone through childbirth. Postpartum depression can have serious symptoms that may affect not only the mother, but her newborn as well. Early detection of these symptoms is of critical importance to the welfare of the mother and her child. Many medical professionals express the need for postpartum screening being that treatment has proven to be very effective. This project aims to make early symptom detection convenient and reliable for mothers with newborns. This will …

Hyperspectral Tomographic Ftir Imaging Using Two Illumination Geometries For Polymer Phantoms, Zahrasadat Alavi

Theses and Dissertations

The purpose of this dissertation is to carry out non-destructive 3D imaging by applying Fourier Transform Infrared (FTIR) spectro-microtomographic techniques, and develop corresponding methods of data analysis. This is done by collecting 3D synchrotron-based and lab-based (Thermal) FTIR hyper spectral data at the Synchrotron Radiation Center (SRC) for the first time. Despite other 2D imaging techniques, this does not manipulate the sample, and suppresses the need to microtome 3D biological, material or biomedical samples into slices to study by spectroscopic imaging techniques. Spectro-micro-tomography is applicable for scientific, industrial, energy, biomedical samples such as stem cell characterization and materials such as …

Hand Pattern Recognition Using Smart Band, Theerth Raj Munusamy

Graduate Theses and Dissertations

The Importance of gesture recognition has widely spread around the world. Many research strategies have been proposed to study and recognize gestures, especially facial and hand gestures. Distinguishing and recognizing hand gestures is vital in hotspot fields such as bionic parts, powered exoskeleton, diagnosing muscle disorders, etc. Recognizing such gesture patterns can also create a stress-free and fancy user interface for mobile phones, gaming consoles and other such devices.

The objective is to design a simple yet efficient wearable hand gesture recognizing system. This thesis also shows that by taking both EMG and accelerometer data into account, can improve the …

Force Sensing In Arthroscopic Instruments Using Fiber Bragg Gratings, Daniel S. Yurkewich

Electronic Thesis and Dissertation Repository

Minimally-invasive surgery has revolutionized many medical procedures; however, it also impedes the ability to feel the interaction between the surgical tool and the anatomical part being operated on. In order to address this problem, it is necessary to obtain accurate measurements of the interaction forces exerted on the surgical tools during surgery. These forces can then be manifested to the surgeon via a haptic device or presented visually (visual-force feedback). This thesis describes the use of a fiber optic device to measure and display to the surgeon interaction forces acting on an arthroscopic tool. The sensorization of the tool involves …

Individual Analysis Of T2*-Weighted Gradient Echo Imaging In Asymptomatic And Symptomatic Athletes, Xianglun Mao

Open Access Theses

Mild traumatic brain injury (mTBI), is a commonly occurred sports-related injury, especially in contact sports like football and soccer. Hemorrhage will appear as hypointense lesions on T₂ ^*-weighted images, resulting from mTBI. Thus, T ₂^*-weighted gradient echo pulse sequence can be used to generate magnitude susceptibility-weighted (SW) images, and to further detect negative intensity changes of different regions of interests (ROIs) inside human brains. Our goal was to investigate how the ROI-specific intensity changes in each individual sports athlete over a single competition season and to interrogate whether these changes are correlated with repetitive subconcussive or …

Development Of A Cell Morphological Analysis Tool To Evaluate The Ultrasound Vibrational Effects On Cell Adhesion, Joseph M. Smith

Dissertations, Master's Theses and Master's Reports - Open

Fibroblast encapsulation is a stage of the wound healing process in which the implanted device is separated from the biological environment due to the formation of fibrotic tissue. Uncontrolled adhesion of fibroblasts, called fibrosis, has the ability to inhibit an implanted device’s functionality over its lifetime. Over time, fibroblasts have been shown to cause loosening and failure of bone-anchor implants which could include the possibility of harming the patient. The encapsulating process could also hinder the sensitivity of implanted biosensors operating in the body for continuous monitoring. Unfortunately, the antifouling surfaces which are commonly used on implanted devices to control …

Experimental-Computational Analysis Of Vigilance Dynamics For Applications In Sleep And Epilepsy, Farid Yaghouby

Theses and Dissertations--Biomedical Engineering

Epilepsy is a neurological disorder characterized by recurrent seizures. Sleep problems can cooccur with epilepsy, and adversely affect seizure diagnosis and treatment. In fact, the relationship between sleep and seizures in individuals with epilepsy is a complex one. Seizures disturb sleep and sleep deprivation aggravates seizures. Antiepileptic drugs may also impair sleep quality at the cost of controlling seizures. In general, particular vigilance states may inhibit or facilitate seizure generation, and changes in vigilance state can affect the predictability of seizures. A clear understanding of sleep-seizure interactions will therefore benefit epilepsy care providers and improve quality of life in patients. …

Multi-Surface Simplex Spine Segmentation For Spine Surgery Simulation And Planning, Rabia Haq

Computational Modeling & Simulation Engineering Theses & Dissertations

This research proposes to develop a knowledge-based multi-surface simplex deformable model for segmentation of healthy as well as pathological lumbar spine data. It aims to provide a more accurate and robust segmentation scheme for identification of intervertebral disc pathologies to assist with spine surgery planning. A robust technique that combines multi-surface and shape statistics-aware variants of the deformable simplex model is presented. Statistical shape variation within the dataset has been captured by application of principal component analysis and incorporated during the segmentation process to refine results. In the case where shape statistics hinder detection of the pathological region, user-assistance is …

Computer Aided Diagnosis Of Oral Cancer: Using Time-Step Ct Images, Jonathan T. Scott

Masters Theses

"In medical imaging it is a very common practice to use a technique known as Time-Step imaging in patients who might develop cancer. Time-Step imaging it a very powerful technique, however it can lead to unmanageable amounts of image data. Previously the only way to search all of this data was to manually look through all of the files. This had to be done by trained professionals who knew what to look for within the images and make a judgment about the patient based on the images. This paper discusses the development of an algorithm to have a computer search …

Assessment Of Electrode Configurations Of Electrical Impedance Myography For The Evaluation Of Neuromuscular Diseases, Khondokar Mohammad Fazle Rabbi

Electronic Theses and Dissertations

Electrical impedance myography (EIM) is a painless, noninvasive approach to measure the neuromuscular disease status. EIM parameters- resistance (R), reactance (X) and phase (θ) depend significantly on subcutaneous fat thickness, muscle size and inter electrode distance. The objective of this research is to find an electrode configuration which can minimize the effects on EIM parameters due to subcutaneous fat thickness variation. In this study, a model of human upper arm was developed using finite element method (FEM), which has already been established as an appropriate approach for the analysis of non-symmetrical shape for assessing alternations of muscle in disease-induced changes …

Design Of A Haptic Interface For Medical Applications Using Magneto-Rheological Fluid Based Actuators, Nima Najmaei

Electronic Thesis and Dissertation Repository

This thesis reports on the design, construction, and evaluation of a prototype two degrees-of-freedom (DOF) haptic interface, which takes advantage of Magneto-Rheological Fluid (MRF) based clutches for actuation. Haptic information provides important cues in teleoperated systems and enables the user to feel the interaction with a remote or virtual environment during teleoperation. The two main objectives in designing a haptic interface are stability and transparency. Indeed, deficiencies in these factors in haptics-enabled telerobotic systems has the introduction of haptics in medical environments where safety and reliability are prime considerations. An actuator with poor dynamics, high inertia, large size, and heavy …

An Optogenetic Brain-Machine Interface For Spatiotemporal Neuromodulation, Ryan Andrew Baumgartner

Theses and Dissertations

Direct neural stimulation has recently become a standard therapy for neurological disorders such as Parkinson's Disease, Essential Tremors, and Dystonia. Currently, deep brain electro-stimulation and neuro-pharmaceutical treatments are the dominant therapeutic options available to the public. As our understanding of brain function and neurological diseases improves, we are able to develop more advanced neuromodulation techniques. These methods could become viable treatment solutions for treating brain dysfunction. Optogenetics, first introduced by a research team led by Karl Deisseroth at Stanford University, has proved to be a versatile technique with remarkable potential to be used in treatments for brain disorders, dysfunction, and …

Induction Of Differentiation Of Dental Pulp-Derived Mesenchymal Stem Cells (Dpsc), Aubrey Young

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mesenchymal stem cells are derived from a variety of human tissues and are being bioengineered and studied for possible uses in the advancement of medicine. Recent efforts are being focused on Dental Pulp Stem Cells (DPSC's) due to the accessibility of this tissue. Many factors influence DPSC quality and quantity, including the specific methods used to isolate, collect, concentrate, and store these isolates once they are removed. Ancillary factors, such as the choice of media, the selection of early versus late passage cells, and cryopreservation techniques may also influence the differentiation potential and proliferative capacity of DPSC isolates.

The objective …

A Low-Power Approach For Front End Biological Signal Conditioning, Logan Smith Taylor

Masters Theses

In a lab-on-a-chip (LOC) application, the measurement of small analog signals such as local temperature variation often involves detection of very low-level signals in a noisy micro-scale environment. This is true for other biomedical monitoring systems as well. These systems observe various physiological parameters or electrochemical reactions that need to be tracked electrically. For temperature measurement pyroelectric transducers represent an efficient solution in terms of speed, sensitivity, and scale of integration, especially when prompt and accurate temperature monitoring is desired.

The ability to perform laboratory operations on a small scale using miniaturized LOC devices is a promising biosensing technique. The …

Algorithm-Circuit Co-Design For Detecting Symptomatic Patterns In Biological Signals, Himanshu Markandeya

Open Access Dissertations

The advancement in scaled Silicon technology has accelerated the development of a wide range of applications in various fields including medical technology. It has immensely contributed to finding solutions for monitoring general health as well as alleviating intractable disorders in the form of implantable and wearable systems. This necessitates the development of energy efficient and functionally efficacious systems. This thesis has explored the algorithm-circuit co-design approach for developing an energy efficient epileptic seizure detection processor which could be used for implantable epilepsy prosthesis. Novel wavelet transform based algorithms are proposed for accurate detection of epileptic seizures. Energy efficient techniques at …

Characterization Of A Contact-Stylus Surface Digitization Method Using Collaborative Robots: Accuracy Evaluation In The Context Of Shoulder Replacement Or Resurfacing, Sara Saud Zimmo

Electronic Thesis and Dissertation Repository

Total shoulder arthroplasty (TSA) is the third most common joint replacement. While robot-assisted hip and knee replacement technologies have enjoyed extensive development, this has been limited in the upper limb. This work focused on quantifying the localization accuracy of a robotic system, and evaluating its efficacy in the context of TSA.

A collaborative robot was fitted with a stylus tip to perform manual surface digitizations using the robot’s encoder output. In the first experiment, two precision-machined master cubes, representing the working volume around a glenoid structure, were used for system validation. Next, cadaveric glenoids were digitized and compared to a …

Evaluating Human Performance For Image-Guided Surgical Tasks, Matthew Kenneth Kramers

Electronic Thesis and Dissertation Repository

The following work focuses on the objective evaluation of human performance for two different interventional tasks; targeted prostate biopsy tasks using a tracked biopsy device, and external ventricular drain placement tasks using a mobile-based augmented reality device for visualization and guidance. In both tasks, a human performance methodology was utilized which respects the trade-off between speed and accuracy for users conducting a series of targeting tasks using each device. This work outlines the development and application of performance evaluation methods using these devices, as well as details regarding the implementation of the mobile AR application. It was determined that the …

Cryoimaging-Microscopy Implementation For 3d Optical Imaging, Mohammad Masoudimotlagh

Theses and Dissertations

The structures and biochemistry properties of biological tissues are mostly affected by diseases. The visualization of organ structure and biochemistry helps in early detection and progression monitoring of diseases.

Although, 2D imaging has traditionally been used to gain information from the tissue, it does not accurately represent many of the structures and functions. There currently exists a need for sensitive and specific methods to show detailed information about the structure of the tissue with high resolution and in 3D. The potential advantage of the high resolution 3D images is the ability to accurately probe structural and biochemical properties of the …

Improving Golf Putt Performance With Statistical Learning Of Eeg Signals, Qing Guo

Graduate Theses and Dissertations

In this thesis, a machine learning based method is proposed to predict the putt outcomes of golfers based on their electroencephalogram (EEG) data. The method can be used as a core building block of a brain-computer interface, which is designed to provide guidance to golf players based on their EEG patterns. The proposed method includes three steps. First, multi-channel 1-second EEG trials were extracted during golfers' preparation of putting. Second, different features are calculated such as correlation coefficient, power spectrum density and coherence, which are used as features for the classification algorithm. To predict golfers' performance, the support vector machine …

Cfd Simulation Of The Thermal Performance Of A Parallel Counter-Parallel Flow Heat Exchanger For The Treatment Of Hypothermia, Alex Heller

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hypothermia is a life-threatening condition. Currently, active warming methods are the most effective treatment for dysthermic patients. The aim of this study is to investigate the use of computational fluid dynamics (CFD) in evaluating the thermal performance of a parallel/counter-parallel flow heat exchanger used as part of a fluid warmer to treat Hypothermia. The 3D model of the heat exchanger is divided into three regions; Infusate (fluid to be heated), Hot Water (heating fluid), and a Solid Region (wall). At the end of the heat exchanger, an elbow section is used to create the counter-parallel flow arrangement specific to this …

Design Of The High-Speed Stereo Radiography System, John C. Ivester Iv

Electronic Theses and Dissertations

Orthopaedic pathologies often involve disruption of the mechanical environment of a joint at/below the mm scale. The ability to measure biomechanical kinematics at the sub-mm scale is essential for obtaining valuable insight into pathologies, but small motions of the joints are difficult to quantify. Estimates of skeletal kinematics are commonly made from optical motion capture systems and markers placed on the skin. The error caused by external marker movement is largely avoided with x-ray motion capture. Dynamic radiography uses a series of x-ray images recorded at high-speed and captures in-vivo joint motion. Uncovering the mechanical foundation of orthopaedic pathologies requires …

Design, Characterization And Application Of A Multiple Input Stethoscope Apparatus, Spencer Geng Wong

Master's Theses

For this project, the design, implementation, characterization, calibration and possible applications of a multiple transducer stethoscope apparatus were investigated. The multi-transducer sensor array design consists of five standard stethoscope diaphragms mounted to a rigid frame for a-priori knowledge of their relative spatial locations in the x-y plane, with compliant z-direction positioning to ensure good contact and pressure against the subject’s skin for reliable acoustic coupling. When this apparatus is properly placed on the body, it can digitally capture the same important body sounds investigated with standard acoustic stethoscopes; especially heart sounds. Acoustic signal inputs from each diaphragm are converted to …

Human Metaphase Chromosome Analysis Using Image Processing, Akila M.S Subasinghe Arachchige

Electronic Thesis and Dissertation Repository

Development of an effective human metaphase chromosome analysis algorithm can optimize expert time usage by increasing the efficiency of many clinical diagnosis processes. Although many methods exist in the literature, they are only applicable for limited morphological variations and are specific to the staining method used during cell preparation. They are also highly influenced by irregular chromosome boundaries as well as the presence of artifacts such as premature sister chromatid separation.

Therefore an algorithm is proposed in this research which can operate with any morphological variation of the chromosome across images from multiple staining methods. The proposed algorithm is capable …

Particle Swarm Optimization Using Multiple Neighborhood Connectivity And Winner Take All Activation Applied To Biophysical Models Of Inferior Colliculus Neurons, Brandon S. Coventry

Open Access Theses

Age-related hearing loss is a prevalent neurological disorder, affecting as many as 63% of adults over the age of 70. The inability to hear and understand speech is a cause of much distress in aged individuals and is becoming a major public health concern as age-related hearing loss has also been correlated with other neurological disorders such as Alzheimer's dementia. The Inferior Colliculus (IC) is a major integrative auditory center, receiving excitatory and inhibitory inputs from several brainstem nuclei. This complex balance of excitation and inhibition gives rise to complex neural responses, which are measured in terms of firing rate …