Biomedical Engineering and Bioengineering Commons^™

Development Of Fmri Compatible Lower Body Negative Pressure System, Pratap Singh Kunwar

Theses

The lower body negative pressure (LBNP) system provides a controlled, measured orthostatic stress to the cardiovascular system, which can be used with a magnetic resonance imaging (MRI) machine to study cardiovascular and cerebrovascular responses to graded LBNP. In the past, even though functional MRI (fMRI) was considered as one of the best modalities with which to measure small metabolic changes in the brain, it has not been used with an LBNP system to measure cerebrovascular changes. This was due to the lack of an fMRI compatible LBNP system.

In this project, an tMRI compatible LBNP system was first constructed without …

Evaluation Of Postural Stability Using Sensory Organization Test, Tiffany Sims

Theses

Poor postural stability of the elderly and other patients has been a major concern.The cost of treating injuries due to poor stability is expected to rise to $32.4 Billion by 2020. Many interventions have been proposed and used to improve stability. In order to determine the efficacy of these interventions, an objective evaluation of postural stability before and after intervention is important.

The aim of this thesis was to scientifically analyze the ambiguities in the equilibrium score (ES) given by the Neurocom Smart Equitest (NSE) machine, and compare it to a new measure of stability that has been proposed by …

Transmission Of Light And Audible Sound In A Synthetic Fog Medium, Bhavin Babaria

Theses

The primary goal of the thesis was to study the propagation of visible light and auditory sound through a synthetic fog medium compared to an ambient air environment. It is known that the fog substantially decreases the visibility however; this has not been studied quantitatively. Further information regarding other energies such as sound is also needed to understand how the energy reacts in the fog medium. The extent of visual and auditory degradation in humans needs to be investigated. Researchers have studied light transmitted through water, air; however, no one has studied how light or sound is transmitted through a …

Study Of Baroreceptor Sensitivity Index In Chronic Fatigue Syndrome, Diane L. Donnelly

Theses

Although numerous studies evaluate baroreflex response as part of their research protocol, only one was identified as having evaluated continuous baroreceptor response as part of a 70° head-up tilt. It was done by Youde et al. [28] and was limited in that it evaluated only sequences of three beats for lag 0. The limitations of the Youde study [28] are not present in this thesis.

The data for this thesis came from a 70° head-up tilt study performed on chronic fatigue syndrome subjects by LaManca et al. [3] at the East Orange VA Medical Center. Baroreflex was not evaluated as …

The Influence Of Exercise On Oxygen Uptake In Mild Hypertension, Matthew Joseph Herban

Theses

The amount of oxygen used by muscle cells increase with exercise. The two body systems that influence the amount of oxygen delivered are the cardiovascular system and the pulmonary system. Two groups of patients were studied, those that were mildly hypertensive (but are not taking prescription medication for hypertension) and the control or normal group. The two groups exercised on a bicycle ergometer. Work rate was increased in steps (multiples of thirty watts) until anaerobic threshold (as measured by an ear oximeter) was reached. Heart rate, blood pressure, oxygen uptake and carbon dioxide production were measured during exercise. Their data …

A Biologically Inspired Joint Model Using Engineering Methods To Enhance Understanding Of Muscle Activity, Richard Paradiso

Theses

Compliant actuators and control methods have been known to exhibit similarities in human musculoskeletal systems. In order to better understand and improve the effects of force optimization under closed- loop conditions, a physical joint model was constructed with an agonist and an antagonist muscle operating under linear control. Utilizing LabVIEW software, compliant McKibben air muscles and Merlin stretch sensors, the author was able to incorporate a Bang-Bang controller and propose the inclusion of pulse width modulation (PWM) as well as a Proportional-Integral-Derivative (PD) controller to study the reflex loops under various levels of feedback sensitivity. The feedback mechanism, similar to …

Implementation Of Cyclic Exercise Protocol On Two Study Groups - Aids And Insomnia, Ujwala G. Kalambur

Theses

Traditional exercise regimens are based on maintaining a prolonged increase in heart rate, followed by a single recovery period. The Cyclic Exercise Protocol is a novel protocol that is designed to create a series of parabolic waves of exercise and recovery. This study involves the implementation of this exercise protocol on two study groups namely AIDS and Insomnia. This exercise protocol involves short bursts of exercise lasting for 60 seconds or less followed by a period of complete aerobic recovery. The underlying principle of this exercise protocol is that rest, recovery and the body's natural rhythm are important to fitness …

Labview-Controlled Stimulus Presentation On A Monitor For Smooth Pursuit Eye Movement Experiments, Florence Bautista Chua

Theses

Smooth pursuit is an example of how movements in the visual world guide involuntary oculomotor movements. A current system to study eye movements uses an oscilloscope screen. A computer screen offers many advantages: a greater visual field, the use of shapes, 32 bits of colors, and increased timing accuracy. To control stimulus display on a computer monitor, instrumentation was developed in LabVIEW. Initial studies supported a draw/redraw to erase method for stimulus presentation. An experiment compared the computer monitor to the oscilloscope. Indeed, the monitor display was an improvement over the oscilloscope for vision research.

Data Recording And Analysis Of American Sign Language, Robert Michael Demarco

Theses

American Sign Language (ASL) is a form of communication that is used by the Deaf. It consists of hand shapes and gestures to express words and phrases. Translators on the market today consist of interpreting a simple form of ASL known as finger spelling. In order to develop a more effective translator, instrumentation was developed utilizing a Flock of Birds and Cyberglove system to record in hand shapes and movements in a LabVIEW environment. Experimentation done included reading in data and subjectively analyzing the data recorded for accuracy. Initial results have show that the instrumentation worked and data was recorded …

The Development Of A Biodegradable Scaffold For A Tissue Engineered Heart Valve, Thomas Adam Alheidt

Theses

In the current state of medical technology, there exists the need for a quality medical device to replace a failing heart valve. Presently, mechanical valves as well as donor tissue valves, either from humans or animals are used to replace failing heart valves. These valves although they can operate in the heart satisfactorily are not equal to the body replacing its own valve. Tissue Engineering in simple terms is the field of helping the body replace its own failing organ. In scientific terms, Tissue Engineering is a relatively young field, a majority of the major advancements have come in the …

Interaction Of Disparity And Accommodative Vergence, Michele Liu Kung

Theses

To fixate on a target that moves from far to near, changes in blur and disparity activate accommodation and disparity vergence. The goal of this study was to experimentally obtain eye movement data from four subjects, and analyze this data using through a new signal processing algorithm known as independent component analysis (ICA). Preliminary data suggest that three underlying neural subcomponents are present where the two components of disparity vergence initiate the movement and the accommodative portion is activated to facilitate the steady state portion of the response.

ICA was used as a blind source separation technique to analyze experimental …

Quantitative Assessment Of Reflex Blood Pressure Regulation Using A Dynamic Model Of The Cardiovascular System, Tanha Patel

Theses

A quantitative understanding of the changes in coronary, pulmonary and systemic hemodynamic variables and their effects on the regulation mechanism is important to the better postoperative management of patients with impaired cardiac function. The arterial baroreflex plays a key role in blood pressure homeostasis, and its impairment may result in exaggerated blood pressure fluctuations and an increased risk of cardiovascular morbid events.

The objective of this work was to construct a mathematical model of the cardiovascular system, which will allow us to simulate the effects of the baroreceptor reflex regulation on sudden changes in blood pressure, caused by sudden changes …

Dimensional Study Of Desaminotyrosyl Polyarylates, Kalsank Vaishali Pai

Theses

Synthetic polymers have found widespread usage and acceptance in various areas of the medical device industry. The recognition that no polymeric biornaterials are truly biocompatible has led to the search for bioerodible materials with desirable biological and physical properties for use as tissue engineering scaffolds and to enable in-vivo devices. Several methodologies have been tried and tested to invent the "ideal" biopolymer. The ideal polymeric biomaterial would be one that offers a favorable response at both the cellular and the systemic level with minimum alteration to its mechanical properties and chemistry. The systematic investigation of process-structure-property space to determine the …

Masseter Muscle Activity Resulting From Stimulation Of Hypothalamic Behavioral Sites : Wavelet Analysis, Anne Marie Petrock

Theses

Patterns of electromyographic (EMG) activity can give an insight into muscle activity associated with a given behavioral state. The masseter muscle is positioned closely to the temporomandibular joint and controls the position and movement of the jaw. The hypothalamus is the region of the brain associated with emotional behavior. In an effort to further understand the muscle activity underlying emotional display, the hypothalamus in two cats was stimulated to evoke a stereotyped emotional response, known as the "rage response." Unsheathing of the claws, retraction of the ears, significant pupillary dilation and vocalization (hissing) characterize this behavior. EMG data obtained at …

Cortical Response To Facial Expressions Of Young Adult Males With Autism Spectrum Disorders And Controls Using Functional Magnetic Resonance Imaging (Fmri), Jagriti Arora

Theses

Autism is a neurodevelopmental disorder that is defined by deficits in social and emotional impairments and this study aims to identify specific brain regions involved during facial processing. The simple task of focusing on the face during social interactions for the normal group is found difficult by the autistic group.

In this study, functional magnetic resonance imaging (fMRI) was used as subjects performed two experimental tasks (EXPLICIT and IMPLICIT) in which a series of photographs of nine males and nine females displaying three affective states (6 fear, 6 happy and 6 neutral) and six scrambled- face control stimuli were presented …

A Computational Model Of Spasticity Based On A Decoupling Of The Alpha And Gamma Efferents, Bruno A. Mantilla

Theses

It is generally accepted that spasticity results from changes in the excitability of the stretch reflex. This change lowers the threshold of the motoneurons of the spinal cord where the integration of a signal from velocity/position sensors is processed and then fed back to the contracting muscle (alphaextrafusal and gamma-intrafusal fibers). The stretch reflex depends on the initial length of the muscle, the stretch velocity and voluntary activity. The exact sequence of the triggering events remains unknown, is poorly understood and as a result is controversial. The clinical classification scales are mainly subjective and by definition, inaccurate.

This computational model …

Development Of A Method To Examine Shear Stress On Cardiomyocytes, Dhawal Desai

Theses

Cardiac hypertrophy is the remodeling or enlargement of the heart exhibited by individuals suffering from heart disease. Cardiac hypertrophy involves two mechanisms, mechanical stresses and humoral changes in the cardiac tissue. One such humoral change involves the Renin Angiotensin System (RAS). The primary fimction of RAS is maintenance of hemodynamics of the body mediated through an effector protein, Angiotensin 11. However, RAS has been shown to play a significant role in the pathophysiology of the heart; contributing to hypertension, cardiac hypertrophy and myocardial infarction. RAS acts through binding of Angiotensin 11 at its receptors. The two forms of Angiotensin 11 …

A Real Time Frequency Analysis Of The Electroencephalogram Using Labview, Rupal Patel

Theses

The use of the Electroencephalogram (EEG) for diagnosis of brain related diseases is becoming a popular technique in the clinical and research environment. To achieve accurate reading of EEG, signal representation and classification becomes extremely important. The goal of this project was to develop a basic software program for acquiring and online processing of the electrical activity recorded from the brain. A program was developed using the LabVIEW programming software by National Instruments. Basic hardware components recorded the EEG signal and a software component divided the data into delta, theta, alpha and beta bands in the frequency domain. Emphasis was …

Study Of The Trajectories Of Visually Guided Movement Of Unimanual And Bimanual Tasks, Deepthi Anand

Theses

Restitution of upper limb mobility following stroke is one of the major challenges facing clinicians in the country today. The complexity of performing skilled tasks with fine movements makes restitution of mobility all the more complex for rehabilitation specialists. Although several techniques have been evolved for, limited success with transfer of training from the clinical environment to functional performance clearly indicates a need for research and development in the area of upper extremity rehabilitation.

Bimanual coordination has recently surfaced as a novel and effective way to fast and lasting recovery. The success of bimanually coordinated training encourages a better understanding …

Thermochemistry Of Vinyl Alcohol And Vinyl Ether Radical And Kinetic Analysis Of Neopentyl Radical Reaction With Molecular Oxygen, Chol-Han Kim

Theses

Vinyl alcohols and ethers are important intermediates in low-temperature combustion processes, such as in the initial stages of combustion and in the atmospheric photochemical oxidation of hydrocarbons. Knowledge of the thermodynamic parameters for these species is central to understanding and predicting their reaction pathways, rate constants, and equilibrium constants. The rapid interconversion of conformers and the instability of vinyl alcohols and ethers lead to complexities in studies of these species.

In this work, enthalpy,ΔH°f 298, entropy, S°298, and heat capacities, Cp(T), are determined for vinyl alcohol and vinyl methyl ether and the radicals corresponding to loss of a H atom …

An Infrared Device To Measure The Eyeblink For The Study Of Classical Conditioning, Alka Patel

Theses

The classically conditioned eyeblink response is studied by various groups to study neurological functions. This is a form of associative leaming that has many features to help diagnose and learn about neurological diseases. Electromyogram traditionally is used to detect eyeblinks for this experimentation in human. However, EMG can be expensive and difficult to use. It involves the utilization of electrodes and produces only an indirect measure of eyelid closure. The goal of the project was to develop an infrared device to detect eyeblinks and replace the EMG. The project involved two major components, a hardware and a software component. The …

Initial Hertzian Characteristics Of The Human Tooth As A Damage Tolerant Bio-Ceramic/Bio-Composite Bi-Layer, Ivory Camille Kilpatrick

Theses

The objective of this thesis was to investigate the Hertzian Contact response of human teeth and how the response behavior is related to that of model ceramic bi-layers (high modulus brittle ceramics on compliant substrates). Hertzian Contact is a blunt indentation method, which uses a hard spherical indenter to apply a normal compressive load. Clinical variables of masticatory (occlusal) force and cuspal curvature identify closely with the independent Hertzian variables of contact load and sphere radius [1]. This method offers insight into the role of microstructure and microstructure- sensitive mechanical properties. It was hypothesized that tooth damage modes and patterns …

Encoding And Storage Components Of Verbal Working Memory As Revealed By A Factorial Design, An Fmri Study, Jason Steffener

Theses

In this fMRI study, the contributions of frontal and posterior brain regions to verbal working memory were investigated. A two-factor design with low and high memory load (2 and 5 letters) and short and long delay (4 and 12 secs.) as factors were used. Based on reports in the literature, we expect activity in the following frontal and parietal brain regions of interest (ROIs): Brodmann areas (BA) 6, 9, 46, 44, 45, 7 and 40. The analysis of collected flvM data involved image processing and statistical analysis methods including realignment, spatial normalization, spatial smoothing, temporal filtering, intensity normalization, statistical tests, …

Partial Characterization Of Extruded Collagen Tubes With Varied Material Deposition And Orientation Based On Rotation Rate And Linear Draw Speed, Richard Peter Hoppe

Theses

This study established protocols for extrusion of collagen tubes from an extruder made by the ZOKO Corporation of Czechoslovakia. Using a viscous collagen base material, collagen tubes can be formed with changes in rotation rates from 0 rpm to 260 rpm and linear draw speeds from 383 mm/min to 1270 mm/min with a constant extrusion rate of 50 cm²/min. These tubes, with further research and treatment, can be used for various medical applications including vascular implants and nerve conduits.

Post-extrusion, chemical crosslinking of the collagen increased the cohesiveness and mechanical integrity of the tubes. Microscopic photographs confirmed higher …

An Automated Approach For Comparative Analysis Of Interval And Heart Rate Variability, Taral Oza

Theses

Cardiovascular disease is the primary cause of death in the adult population. Half of these cardiac deaths occur as sudden death. Some of the parameters from the surface ECG recording (a noninvasive technique) carry important information and have special significance in research, as they are good indicators of diseases leading to heart attacks, sudden cardiac death and other similar cardiac problems. Measurement of QT interval variability and heart rate variability are two such parameters, which has received much attention of researchers.

An algorithm has been developed to measure and compare the two significant parameters, the QT interval variability and the …

Autonomic Activity In Gulf War Veterans Using Heart Rate And Systolic Blood Pressure Variability, Maryann S. Fam

Theses

Heart rate variability (HRV) describes variations of heart rate and is attributed to cyclic fluctuations in autonomic tone. The different methods of heart rate variability analysis allow for a non-invasive assessment of autonomic activity. This study analyzes the heart rate variability through both frequency domain methods and joint time-frequency domain methods which were executed through the LabVJEW graphical programming language. These algorithms were utilized to assess autonomic nervous system activity in Gulf War veterans with no health complaints versus Gulf War veterans with chronic fatigue syndrome. The heart rate variability analysis was obtained from acquired measurements of heart rate and …

Drowsy Driver Data Acquisition System, Rafael Norat

Theses

This thesis focuses on detecting the drowsiness of a driver based on differentiation of the EEG signal activity between the eyes open and eyes closed states. Here, it is observed that there is a significant increase 'in a 10 Hz component of the alpha rhythm activity when the subject under test closes his / her eyes. This phenomenon was observed when electrodes were attached to the occipital region. A more desirable approach is to develop a non-intrusive measurement based on a multiturn differential coil combination utilizing a low noise high gain amplifier. The system developed here used an 80,000 turn …

A Study Of The Parameters And Stipulations Involved In The Design Of Prosthetic Limb Socket Liners, Sally F. Shady

Theses

The objective of this thesis is to illustrate the parameters that define and characterize the elements necessary for an optimal prosthetic socket interface design. Previous studies have revealed that the industry is manufacturing materials that are causing irregularities in gait patterns and causing major discomfort for transtibial amputees. As a result, chances for recovery and rehabilitation of many patients have been greatly reduced.

This study has indicated that the success of a socket liner depends on quantitative and qualitative factors that assess the overall efficacy of an artificial limb. Quantitative analysis is observed through calculations and deviations in gait cycles, …

Biomechanical Evaluation Of Patient Transfers, Charles Costa

Theses

The purpose of this study is to identify the problem encountered when a patient with limited strength and mobility needs assistance in transferring from a wheelchair to another location.

This study took advantage of ergonomic techniques to isolate the source of stress, and limited these stresses according to the standards of the National Institute of Safety and Health Administration.

A device was developed whereby the stresses of a patient transfer were eliminated. By using a conventional wheelchair and a recliner as a starting point, effectively combining these components into a single multifunctional unit the goal of reducing stress was achieved. …

Late Deflation Study : Hemodynamic Effects Of Iab Timing In Humans, Manal Morcos

Theses

Conventional IABP timing deflates 100% of the balloon volume before the onset of left ventricular ejection and has been well established in the literature as a safe and effective method. Yet, recent studies suggest that deflation of the IAB at or near the onset of systole improve myocardial efficiency (Kern, 1999, 1129). To test whether deflation of the JAB at a later deflation time reduces left ventricular workload and enhances coronary perfusion, four timing methods were evaluated in 20 patients: T₁ (100% JAB volume deflated before onset of ejection), T₂ (60% IAB volume deflated before and 40% volume …