Master of Science, The Ohio State University, 2019, Mechanical Engineering

The body has various physiological responses to any form of exercise, which include an increase in ventilation, oxygen uptake, and heart rate as work-load increases. The body relies on breathing to fuel the working muscles with oxygen during exercise, and this fuel ultimately allows the exercise being performed to continue. Respiratory inductance plethysmography (RIP) is a method of monitoring breathing through the placement of elastic belts around the chest and abdomen, and through this method it is known that the most efficient breathing entails the chest and abdomen expanding and contracting at the same time. This research therefore sought to examine if providing runners with real-time visual feedback on the breathing pattern of the chest and abdomen during a run could improve time to exhaustion. 13 recreational runners (8 females, 5 males) were put through a treadmill fatigue protocol to voluntary exhaustion on two separate days. The testing days followed the same procedures with the one difference being whether visual feedback was provided during the treadmill fatigue protocol. Visual feedback on the chest and abdomen were provided through animations created in LabVIEW, with each animation being independently controlled via the method of RIP. Phase angle was calculated as an average over each running interval of interest. A phase angle closer to zero degrees signifies more efficient and synchronous movement of the chest and abdomen during breathing. Time to exhaustion was not significantly improved when visual feedback was provided (p = 1). Phase angle had a negative correlation with visual feedback (r = -0.089) but was not significant (p = 0.667). Six participants had an improved phase angle when visual feedback was provided, and in turn four of the participants had an improved time to exhaustion. Furthermore, three of these six participants improved phase angle by a value of 9 degrees or better, and all three of these participants improved time to exhau (open full item for complete abstract)

Committee: Ajit Chaudhari PhD (Advisor); Rob Siston PhD (Committee Member) Subjects: Mechanical Engineering

Master of Sciences, Case Western Reserve University, 2022, EMC - Aerospace Engineering

One of the primary stresses associated with flying high performance aircraft is acceleration, referred to as “G-force”. A critical method to combat the metabolic effects of high-G maneuvers is the Anti-G Straining Maneuver (AGSM), a respiratory technique designed to offset the effects of high-G on the human body. A dedicated and extensive flight test program is carried out to analyze the performance of legacy breathing systems during maneuvers between +3 and +5 G. A pilot mounted sensor package is utilized to obtain metabolic data during individual sorties. Data is recorded for breathing systems holding the pilot breathing mask at 100% oxygen and positive pressure (+2-3 mmHg relative to the cabin) as well as systems following a pressure dependent oxygen dilution schedule at net zero pressure. This data is utilized to characterize the effects of the AGSM on pilot breathing and identify shortcomings in the response to AGSM breathing.

Committee: Paul Barnhart (Committee Chair); Bryan Schmidt (Committee Member); Stephen Hostler (Committee Member) Subjects: Aerospace Engineering; Engineering; Fluid Dynamics; Mechanical Engineering; Physiology

PhD, University of Cincinnati, 2001, Nursing : Doctoral Program in Nursing

In spontaneous breathing modes, past laboratory work using a lung model indicated portable ventilators as compared to critical care ventilators may increase inspiratory work of breathing. The purpose of this study was to assess the imposed inspiratory work of breathing and breathing comfort of nonintubated healthy volunteers breathing spontaneously through three portable ventilators and a critical care ventilator in a controlled environment. A physiologic theoretical framework was used for the study. With all subjects having continuous positive airway pressure (CPAP) settings of 0 and 5 cm H2O and pressure support ventilation (PSV) settings of 0 and 10 cm H2O, the hypotheses were: 1) Imposed work (WOBI) and pressure-time product (PTPI) with the 7200ae (Mallinckrodt, critical care ventilator) will be less than those in the Achieva (Mallinckrodt) ventilator and LTV 1000 (Pulmonetic) ventilator, which will be less than those of the Univent 754 (Impact) ventilator (WOBI and PTPI with 7200ae < Achieva = LTV 1000 < Univent 754); 2) breathing comfort (BC) reported by subjects breathing with the 7200ae will be greater than that with the Achieva and LTV 1000, which will be greater than the Univent 754 (BC with 7200ae > Achieva = LTV 1000 > Univent 754). The study used a randomized, single blind repeated measures design using healthy nonobese subjects (n=16). Measured respiratory parameters were saved to a personal computer and subjects recorded BC on a visual analogue scale that had been previously assessed for validity. Control breathing periods were interposed after each fourth study period; maximum inspiratory pressure was the proxy measure for fatigue. Baseline airway pressure was determined in real-time and retrospectively with the differences compared for each ventilator and control period. Repeated measures ANOVA was used to analyze the data with α < 0.05. There were no significant differences in the measures during the control breathing periods or in baseline airway (open full item for complete abstract)

Committee: Marilyn Sommers (Advisor) Subjects: Health Sciences, Nursing

Doctor of Philosophy, The Ohio State University, 2007, Educational Policy and Leadership

Increased participation of competitive athletes in new methods of simulated altitude warrants research on changes in performances. PURPOSE: To ascertain the effects of intermittent simulated altitude exposure via re-breathing on cycling performance. METHODS: Eighteen, well-trained male cyclists use a re-breathing device for 15 days. Subjects were randomly assigned to either a low constant exposure group (CON) in which oxygen saturation was held constant (98%); or progressively increased exposure group (TRT), where oxygen saturation was progressively reduced (90% to 77% over 15 days). An exercise performance test was performed to familiarize subjects to the protocol (FAM), prior to simulated altitude exposure (PRE) and following simulated altitude exposure (POST). The critical power protocol was used to examine power output in varied time trial (TT) efforts. Performance was also investigated through measurements of lactate, oxygen consumption (VO2), and heart rate (HR). Blood characteristics examined include hematocrit, reticulocyte and serum Ferritin values. RESULTS: There was significant improvement (p=.004) for the TRT group at POST in the 15m TT (PRE = 325.0 ± 12.2 watts, POST = 335.0 ± 11.9 watts) and estimated 60m TT (PRE = 300.1 ± 28.4; POST = 322.4 ± 36.1) compared to no improvement in the CON group. The TRT group improvement was 3-4.5% in average power output. There were no significant differences in the power outputs of the 3m TT at POST for either group. There were no significant differences in haematological measures at POST for either group. A decreased VO2 Index (p=.075) and a significant decrease (p = .026) in HR Index (HRavg/wattavg) was revealed for the TRT group (PRE = 0.564 ± 0.044; POST = 0.544 ± 0.053). CONCLUSIONS: In competitive cyclists, the use of a re-breathing device resulted in improved performance for events which rely heavily on aerobic power but none for anaerobic power. These findings are similar in regard to performance adaptations fo (open full item for complete abstract)

Committee: Timothy Kirby (Advisor) Subjects: Health Sciences, Recreation

Doctor of Nursing Practice, Mount St. Joseph University , 2024, Department of Nursing

Mechanical ventilation is a lifesaving therapy frequently used in intensive care units for critically ill patients. More than thirty percent of critically ill patients will require mechanical ventilation. Continuous sedation often accompanies mechanical ventilation to promote comfort and compliance with the ventilator. The longer the patient remains on a mechanical ventilator, the more of a risk the patient is apt to develop ventilator-associated events, pneumonia, acute respiratory distress syndrome, immobility, and psychosis. This can have a significant impact on the patient's overall outcome, length of stay, and risk for mortality. Early extubation is shown to be effective in the prevention of these associated risks. The use of light sedation, daily awakening trials with coordinated breathing trials have a significant positive impact on the critically ill patient. The goal of this Doctor of Nursing Practice (DNP) evidence-based practice quality improvement (EBP-QI) project was to improve patient outcomes by implementing a standardized spontaneous awakening trial with a coordinated breathing trial protocol. The Johns Hopkins Nursing Evidence-Based Practice Model and the American Association of Critical-Care Nurses (AACN) Synergy Model for Patient Care were the evidence-based practice model and theoretical framework used to guide this project. This project's outcome was to decrease ventilator days and hospital length of stay. 64 nurses participated in the new protocol education. While this study did not show a significant reduction in either ventilator days or hospital length of stay, a significant increase in protocol compliance and nurse comfort in initiating a spontaneous awakening trial was seen. These improvements can lead to a decrease in ventilator days and hospital length of stay overtime.

Committee: Sandra Curtis (Advisor) Subjects: Nursing

Doctor of Philosophy, University of Toledo, 2022, Educational Psychology

This study utilized a convergent-parallel mixed methods design to explore the usefulness of a remote relaxation-based intervention's ability to foster mindfulness and self-determination for stress management by collegiate athletes. Although stress is a common experience related to college retention, collegiate athletes experience additional stressors related to athletic training and performance. Through thematic analysis, this research found that collegiate athletes identified managing academics, time management, use of technology, and finances as primary stressors. A remote relaxation-based intervention was offered the participants an opportunity to learn and experience deep breathing, guided imagery, mandala coloring, and self-hand massage interventions designed to increase mindfulness and coping for stress management while strengthen the basic psychological needs. Participant self-reports, identified that they were able to learn active coping skills that allowed them to manage stressors. They demonstrated mindfulness related to identification of their stress through their self-reports of symptoms, need for interventions, and benefits of techniques learned. Although statistical significance was not found, triangulation of the data allowed for a rich understanding of participants experiences and demonstrated that the participants were able to utilize the techniques learned to manage their stress levels with positive outcomes. Participants also reported that they were utilizing the techniques learned outside of the intervention sessions to manage stress. At the conclusion of the interventions, participants reported that if such interventions were made available to them on campus, nearly half reported they would utilize these resources again, demonstrating buy-in for the usefulness of the techniques by the participants.

Committee: Revathy Kumar (Advisor) Subjects: Educational Psychology; Higher Education; Mental Health; Peace Studies; Recreation

Doctor of Philosophy (PhD), Wright State University, 2021, Biomedical Sciences PhD

The carotid bodies (CB) are peripheral chemoreceptors that detect changes in arterial oxygenation and, via afferent inputs to the brainstem, correct the pattern of breathing to restore blood gas homeostasis. Elucidating the “signal” that couples carotid body sensory type I cell (CBSC) hypoxic mitochondrial inhibition with potassium channel closure has proven to be an arduous task; to date, a multitude of oxygen-sensing chemotransduction mechanisms have been described and altercated (Varas, Wyatt & Buckler, 2007; Gao et al, 2017; Rakoczy & Wyatt, 2018). Herein, we provide preliminary evidence supporting a novel oxygen-sensing hypothesis suggesting CBSC hypoxic chemotransductive signaling may in part be mediated by mitochondria-generated thermal transients in TASK-channel-containing microdomains. Confocal microscopy measured distances between antibody-labeled mitochondria and TASK-potassium channels in primary rat CBSCs. Sub-micron distance measurements (TASK-1: 0.33 ± 0.04µm, n = 47 vs. TASK-3: 0.32 ± 0.03µm, n = 54) provided the first direct evidence for CBSC oxygen-sensing microdomains. Using a temperature-sensitive dye (ERthermAC), hypoxic-inhibition of mitochondrial oxidative phosphorylation in CBSCs was suggested to cause a rapid and reversible inhibition of mitochondrial thermogenesis and thus temperature in these microdomains. Whole-cell perforated-patch current-clamp electrophysiological recordings demonstrated CBSC sensitivity of resting-Vm to temperature: lowering bath temperature from 37°C to 24°C induced consistent and reversible depolarizations (Vm at 37°C: -48.4 ± 4.11mV vs. Vm 24°C: -31.0 ± 5.69mV; n = 5; p<0.01) in isolated, primary rat CBSCs. We propose that hypoxic inhibition of mitochondrial thermogenesis may play a critical role in hypoxic chemotransduction in the carotid body. A reduction in temperature within cellular microdomains will inhibit plasma membrane ion channels, influence the balance of cellular phosphorylation–dephosphorylation, and (open full item for complete abstract)

Committee: Christopher N. Wyatt Ph.D. (Advisor); Eric S. Bennett Ph.D. (Committee Member); Paula A. Bubulya Ph.D. (Committee Member); Kathy Engisch Ph.D. (Committee Member); Robert M. Lober M.D., Ph.D. (Committee Member) Subjects: Biomedical Research; Cellular Biology; Neurobiology; Neurosciences; Physiology

Master of Dental Hygiene, The Ohio State University, 2021, Dental Hygiene

Musculoskeletal Disorders are a growing problem that can cause time off, loss of production, early retirement, and permanent disability. Among the growing number of professionals that suffer from M.S.D., dental hygienists remain at high risk due to their repetitive and static tasks involved with their occupation. Learning ways to maintenance the body early on will help to control some of the M.S.D. pain and reduce the risks involved. Yoga has been a popular alternative therapy to control M.S.D. pain along with reducing stress that can heighten M.S.D. symptoms. The purpose of this study is to determine if simple yoga and breathing exercises can help mitigate M.S.D. pain and stress when incorporated before the clinical working day in dental hygiene students. Junior and senior dental hygiene students were randomly selected to control (n=13) and treatment groups (n=13). The treatment group completed preclinical yoga stretching and breathing exercises for seven weeks. At weeks one and seven, each group completed the Standardized Nordic Questionnaire (S.N.Q.) and the Modified Dental Environment Stress Questionnaire (MDESQ). The sum of M.S.D. pain resulted in no significant difference in musculoskeletal trouble (ache, pain, discomfort) between the control and treatment groups for Questionnaire 1 (Q1) and Questionnaire 2 (Q2). Overall stress outcomes were compared on the sum of group stressors between control and treatment groups. While living, personal, and education environmental stressors were not significant between the groups, academic and clinical stressors were significantly different between the groups.

Committee: Rachel Kearney BSDH, MS (Advisor); Rebecca Henderson BSDH, MS (Committee Member); Erin Gross D.D.S., Ph.D., MS (Committee Member) Subjects: Dentistry; Health Care

Doctor of Philosophy, The Ohio State University, 2020, Biomedical Engineering

Abdominal aortic aneurysm (AAA) is a vascular disorder in which an abnormal and non-reversible dilation develops within the infrarenal aorta. Most AAAs remains asymptomatic until catastrophic rupture. The overall mortality rate resulted by AAA rupture is between 65% and 90%. AAA rupture claims about 15,000 lives in the United States per year, making it the 15th leading cause of death in the country. Recent advances in cardiovascular medicine have not lowered AAA mortality rate globally. Prevention of rupture is a main goal of AAA management. Currently, AAA size has been used to evaluate its rupture potential. Aneurysm repair is usually recommended when the maximum diameter exceeds 5.5 cm. Multiple studies have suggested that this criterion may not be reliable, especially for small AAAs (<5.5cm). Recent studies have demonstrated that biomechanical properties such as AAA stiffness play an important role in determining aneurysm expansion and rupture. The stiffness of an aneurysm is associated with its extracellular matrix (ECM) components and the way in which they are organized. Extensive ECM remodeling causes loss of wall strength and then eventual wall rupture. The substantial remodeling of elastin and collagen as well as mineralization can be assessed by studying the variation of AAA stiffness, making aortic stiffness a potential biomarker for evaluating the progression of an AAA. Ex vivo mechanical testing is an excellent research tool, but it is not a viable technique for stiffness measurement under a clinical setting. Currently, few techniques are available to measure in vivo aortic stiffness. Pulse wave velocity-derived stiffness, despite its wide acceptance, has its own technical limitations. Ultrasound-based elastography largely relies on semi-quantitative estimation. Magnetic resonance elastography (MRE) is a non-invasive phase-contrast MR technique where the shear modulus of soft tissues can be spatially estimated. In our pilot studies, the initi (open full item for complete abstract)

Committee: Arunark Kolipaka PhD (Advisor); Rizwan Ahmad PhD (Committee Member); Gunjan Agarwal PhD (Committee Member); Michael Go MD (Committee Member) Subjects: Biomechanics; Biomedical Engineering; Health Care; Medical Imaging; Radiology

Doctor of Philosophy, University of Akron, 2020, Biomedical Engineering

Obstructive Sleep Apnea (OSA) is a common pediatric breathing disorder which leads to complete or partial obstruction of the airway while sleeping. It occurs in pediatric patients due to enlarged tonsils (tonsillitis), obesity, cranio-facial abnormalities and facial muscle-related disorders that lead to hypotonia thereby resulting in obstruction of the airway. Polysomnography (PSG) is the gold standard overnight systemic study to diagnose sleep apnea. The quality of data obtained from various sensors in an overnight PSG is important for good diagnosis, but sometimes the data obtained from the thermistor sensor is usually corrupted by the use of a pacifier by pediatric patients that may use them during the study. Hence the corrupted data is discarded and not used for analysis. This causes a problem as the thermistor data captures apnea (complete reduction of airflow) and hypopnea (partial reduction of airflow) events and can lead to an incorrect Apnea Hypopnea Index (AHI) which is the total number of apnea and hypopnea events in an hour of the study. In the first objective, we set up a Bayesian framework to compute the probability of having an apnea and hypopnea event while taking into consideration the data from other sensors from the artifact-free part of the data and applied that probability to artifact part of the data. This determined the probability of the number of events that could be hidden behind those artifacts and in turn led to a revised AHI score which is usually higher than the actual score. This is of great value to the physician as the AHI score plays a major role in determining the standard of care or the diagnostic procedure that will be given to the patient after the PSG. As an example, for one particular patient a score of 4 was increased to greater than 5, and would have led to a different treatment plan. The second objective of the study was to use signal processing techniques to remove the artifacts from the thermistor data. This would pr (open full item for complete abstract)

Committee: Ajay Mahajan (Advisor); Lawrence Noble Jr. (Committee Member); James Keszenheimer (Committee Member); Jiang Zhe (Committee Member); Sujay Datta (Committee Member) Subjects: Biomedical Engineering

Doctor of Musical Arts, The Ohio State University, 2020, Music

The clarinet has been favorably compared to the human singing voice since its invention and continues to be sought after for its expressive, singing qualities. How is the clarinet like the human singing voice? What facets of singing do clarinetists strive to imitate? Can voice pedagogy inform clarinet playing to improve technique and artistry? This study begins with a brief historical investigation into the origins of modern voice technique, bel canto, and highlights the way it influenced the development of the clarinet. Bel canto set the standards for tone, expression, and pedagogy in classical western singing which was reflected in the clarinet tradition a hundred years later. Present day clarinetists still use bel canto principles, implying the potential relevance of other facets of modern voice pedagogy. Singing techniques for breathing, tone conceptualization, registration, and timbral nuance are explored along with their possible relevance to clarinet performance. The singer `in action' is presented through an analysis of the phrasing used by Maria Callas in a portion of `Donde lieta' from Puccini's La Boheme. This demonstrates the influence of text on interpretation for singers. Together, these points suggest that voice pedagogy may be used to positively influence clarinet performance and pedagogy, ensuring that clarinetists will continue the tradition of `making the clarinet sing.'

Committee: Caroline Hartig (Advisor); Scott McCoy (Committee Member); Eugenia Costa-Giomi (Committee Member); Katherine Borst Jones (Committee Member) Subjects: Music; Music Education

Doctor of Philosophy (PhD), Ohio University, 2019, Physics and Astronomy (Arts and Sciences)

Two different materials, a non-glass former (a-Si) and a glass former (Ag0.2(Ge35Se65 0.8), were considered for investigation. New structural models of these systems were obtained using state of the art methods. Several physical, electrical, and dynamical attributes of these materials were computed, which revealed atomistic structure, vibrational, electronic and transport properties. To create high-quality continuous random network models of a-Si is difficult using conventional methods. A recently developed algorithm, force-enhanced atomic refinement (FEAR), has shown to provide excellent models. To illustrate this, an investigation was performed with respect to the structural, electronic, and vibrational properties of amorphous silicon, which consisted of several model types of different sizes that were constructed from melt-quench (MQ) and FEAR methods. The results from the FEAR models, as compared to the MQ models, correlated more closely with experiment, even for relatively large structure sizes. In addition, FEAR is generally about a factor of 10 faster than conventional methods. Next, we investigated the static and dynamical properties of a ternary glassy material Ag0.2(Ge35Se65)0.8 using ab initio molecular dynamics (AIMD). The results indicated the host network to be rigid and that additional substructures exist in the model. The radial distribution function of the Ag0.2(Ge35Se65)0.8 model revealed reasonably good agreement with experiment. It has been shown that the model consists of Ge(Se1/2)4 tetrahedra which are quite distorted from ideal. To better comprehend the dynamical properties of this model we performed a detailed analysis of the vibrational modes, which we believe to be a first for such a system. Finally, we examined A1 breathing modes of the corner-sharing tetrahedra where we affirm that these breathing modes are non-local and involve the mixing of modes for different symmetry which results in two bands of A1 breathing modes, thus emphasizing (open full item for complete abstract)

Committee: David Drabold (Advisor); David Ingram (Committee Member); Gang Chen (Committee Member); Horacio Castillo (Committee Member); R Damian Nance (Committee Member) Subjects: Condensed Matter Physics; Theoretical Physics

Master of Science in Computer Engineering (MSCE), Wright State University, 2018, Computer Engineering

Mindfulness is the state of retaining awareness of what is happening at the current point in time. It has been used in multiple forms to reduce stress, anxiety, and even depression. Promoting Mindfulness can be done in various ways, but current research shows a trend towards preferential usage of breathing exercises over other methods to reach a mindful state. Studies have showcased that breathing can be used as a tool to promote brain control, specifically in the auditory cortex region. Research pertaining to disorders such as Tinnitus, the phantom awareness of sound, could potentially benefit from using these brain control strategies as the auditory cortex is suspected of being the region in the brain responsible for the production of symptoms associated with Tinnitus. Mobile Applications have become an increasingly popular tool, due to their accessibility, that can be used to promote mindfulness, and as a result help patients cope better with Tinnitus. Using applications to guide patient's breathing patterns could be a more desirable and effective method to attaining a more mindful state. This study explores the effectiveness of such an application, and how the application can modified to be adaptive towards each individual user. Two questionnaires, Attentional Control Scale (ACS) and Mindful Attention Awareness Scale (MAAS), are used to measure self-reported attentional control and mindfulness. The results obtained from the questionnaires along with number of times the application was used, were used to determine which features, and whether using the application more times, had an effect on a participant's mindful score. Machine learning regression trees and ANOVA was used as part of the analysis, but due to lack of data, concrete conclusions on whether using the application more times has a better affect on a participant's mindfulness could not be established. That said future work will include a larger more diverse dataset which could allo (open full item for complete abstract)

Committee: Subhashini Ganapathy Ph.D. (Advisor); Mateen Rizki Ph.D. (Committee Member); Michael Raymer Ph.D. (Committee Member) Subjects: Computer Engineering; Computer Science; Design; Industrial Engineering; Mental Health; Neurosciences

Master of Science (MS), Wright State University, 2017, Physiology and Neuroscience

The carotid bodies (CB), the primary peripheral chemoreceptors, respond to changes in blood gases with neurotransmitter release, thereby increasing carotid sinus nerve firing frequency and ultimately correcting the pattern of breathing. It has previously been demonstrated that acute application of the adipokine leptin caused perturbations of intracellular calcium and membrane ion movement in isolated CB Type I cells (Pye et al, 2015) and augmented the response of the intact CB to hypoxia (Pye et al, 2016). This study's aim was to examine, in-vivo, if elevated leptin modulated CB function and breathing. Rats were fed high-fat chow or control chow for 16-weeks. High-fat fed (HFF) animals gained significantly more weight compared to control fed (CF) animals (n=18; p<.001; 512.56 g ± 14.70 g vs. 444.11 g ± 7.09 g). HFF animals also had significantly higher serum leptin levels compared to CF (n=18; p<.0001; 3.05 ng/mL ± 0.24 ng/mL vs. 1.29 ng/mL ± 0.12 ng/mL). Whole-body plethysmography was used to test the acute hypoxic ventilatory response (HVR) in unrestrained, conscious animals. HFF animals had an attenuated 2nd-phase of the HVR when compared to CF (n=18; p<.05; 710.1 ± 41.9 mL kg-1 min-1 vs. 855.4 ± 44.05 mL kg-1 min-1). CB Type I cells were isolated and intracellular calcium measured; no significant differences in the cellular hypoxic responses between groups were observed. These data show differences in the 2nd-phase of the HVR caused by high fat feeding are unlikely to be caused by an action of leptin on the Type I cells. However the possibility remains that leptin may have in-vivo postsynaptic effects on the carotid sinus nerve; this remains to be investigated.

Committee: Christopher Wyatt Ph.D. (Advisor); Eric Bennett Ph.D. (Other); David Ladle Ph.D. (Committee Member); Mark Rich M.D./Ph.D. (Committee Member); Robert Fyffe Ph.D. (Other) Subjects: Biology; Cellular Biology; Neurosciences; Physiology

Doctor of Philosophy, The Ohio State University, 2017, Electrical and Computer Engineering

Tail-controlled missiles, hard-disk drives and multi-link flexible manipulators all share a common trait - nonminimum phase (NMP) property of their dynamical models. The NMP property can be described as the presence of unobservable or internal dynamics which are unstable when the output is identically zero, by a suitable choice of input and initial conditions. The NMP property poses a significant challenge for control systems design by imposing limitations on the controller structure. Specifically, it prohibits the use of typical inversion based control techniques. In this dissertation, the NMP property is considered as it appears in aerospace applications, specifically air-breathing hypersonic vehicles (HSV). Air-breathing hypersonic vehicles, powered by scramjet engines, are intended to achieve long-duration hypersonic flight at airspeed exceeding Mach 5. HSVs have extensive military applications and have the potential for use as atmospheric reentry vehicles, which would improve access to space travel. The NMP property is seen in HSVs due to vehicle frame being tightly integrated with the propulsion system, causing an elevator-to-lift coupling. In addition to NMP behavior, hypersonic vehicles experience flexible effects from the fuselage. Furthermore, the vehicle models available for control design are not fully known, with uncertainty in the aerodynamic forces and moment. A suitable controller for the HSV must stabilize the internal dynamics, obtain a desirable response for the vehicle outputs and be robust to model uncertainties. In this study, the longitudinal dynamics of the HSV are considered, with the objective of achieving a desired trim condition in vehicle airspeed and altitude. Two solutions that address the issues with hypersonic vehicles are presented here. First, is a modular adaptive control method with input-to-state analysis of internal dynamics. In this case, the output is redefined with pitch angle as a dummy output such that the inter (open full item for complete abstract)

Committee: Andrea Serrani Prof. (Advisor); Kevin Passino Prof. (Committee Member); Abhishek Gupta Prof. (Committee Member) Subjects: Electrical Engineering

MFA, Kent State University, 2017, College of Communication and Information / School of Visual Communication Design

The rising crescendo of the digital lifestyle has profoundly affected the human capacity for sustained focus. Since 2000, the human attention span has dropped from 12 to 8 seconds, with decreased long-term focus as users increase digital consumption. With users not getting off their devices anytime soon, and technostress on the rise, the question arises how designers might better meet users where they are by designing more mindful interactions. Research in the field of mindfulness shows its potential to reduce stress, increase productivity, and improve overall wellbeing. Mindfulness-based design, or mindful design, focuses on creating opportunities for users to become more attentive to their present state of awareness. The opportunity for this design research is in response to what Linda Stone, technology consultant, calls “screen apnea,” or the experience of shallow breathing or breath holding while doing email, or while working or playing in front of a screen. According to Stone, 80% of people do not breathe properly when using screen devices and the implications are increased stress levels, diminished emotional well-being and attitude, as well as reduced productivity. Using the breath as the primary focus, the goal of this design research is to understand the relationship between the visual components of rhythmic visualizations—direction, hue, brightness, temperature, saturation, contrast, and imagery—and the factors that affect mindfulness through breath awareness for long-term desktop users. The extended goals of this research are to integrate the findings into the development of a web-based tool—potentially a browser extension—to enhance mindfulness and minimize digital stressors.

Committee: Gretchen Rinnert (Advisor); Jessica Barness (Committee Member); Jillian Corey (Committee Member) Subjects: Communication; Design

Master of Science (MS), Ohio University, 2016, Athletic Training (Health Sciences and Professions)

The physiological respiratory pump has the potential of encouraging a morevefficient venous return of the lower extremity. This study examined the effects of a diaphragmatic breathing pattern coupled with three common swelling reduction techniques on venous return of the ankle. A pretest-posttest true experimental design was used in this study to compare ankle swelling reduction rates of selected venous returninterventions. Venous return in the lower limbs is substantially decreased as a result of gravitational forces acting down on the body. This does not eliminate the possibility of allowing for faster return of blood to the heart, however. When a patient has swelling to a body site, there are several interventions that are clinically practiced to promote venous return. These interventions include: elevation, sequential compression, and muscle pumps. The respiratory pump is the most powerful mechanism of venous return, but it has not yet been clinically tested or applied. This study randomly placed participants into three intervention groups and implemented each with or without the respiratory pump using a diaphragmatic breathing pattern. This study determined that there was no statistical or clinical significance between elevation, sequential compression, or muscle contraction with forced inhalation compared to elevation, sequential compression, or muscle contraction without forced inhalation. There was also no statistical or clinical significance between the swelling reduction techniques. Forced inhalation using a diaphragmatic breathing pattern did not significantly promote a faster venous return and reduction of swelling. However, the study was underpowered; a larger number of participants was needed to find both statistical and clinical significance. Further research is needed to investigate the power of the respiratory pump in venous return to the lower extremity.

Committee: Chad Starkey (Committee Chair); Jeff Russell (Committee Member); Janet Simon (Committee Member) Subjects: Alternative Medicine; Anatomy and Physiology; Health; Health Care; Medicine; Occupational Therapy; Physical Therapy; Physiology; Sports Medicine; Therapy

Psy. D., Antioch University, 2015, Antioch New England: Clinical Psychology

This dissertation assessed the role of heart rate variability (HRV) in the treatment of migraine headaches. The extent of this relationship was measured through a 12-session HRV biofeedback protocol to increase HRV and decrease migraine frequency through resonance frequency breathing (RFB) training. This project used a single-case design methodology to analyze phase changes in physiological variables with a specific focus on changes in HRV and migraine symptoms from baseline to completion of the biofeedback protocol. The prevalence of migraine headaches is discussed, the history of biofeedback as an intervention for migraine is reviewed, and the rationale for the relationship between HRV and somatic symptoms is presented. Conceptual frameworks for biofeedback provide rationale for the intervention. The study reviews the participant's history of migraine symptoms, phase changes throughout the protocol, and changes in migraine symptoms during the follow-up phase. Overall, the study did not find a strong relationship between HRV and migraine symptoms. The participant's migraine frequency decreased throughout the protocol without a significant phase change in HRV. There were observed phase changes in other physiological variables consistent with increased autonomic regulation. Overall, the HRV biofeedback protocol did have a positive impact on migraine symptoms without a significant phase change in HRV.

Committee: Victor Pantesco EdD (Committee Chair); Inna Khazan PhD (Committee Member); Catherine Schuman PhD (Committee Member) Subjects: Clinical Psychology

Doctor of Philosophy (PhD), Wright State University, 2012, Biomedical Sciences PhD

Chemosensitive LC neurons increase their firing rate in response to increased CO2 (hypercapnia) in part via inhibition of K+ channels. This increase gets smaller during the first two postnatal weeks (neonatal rats aged P3-P16). Alterations of this “accelerating” pathway may account for the developmental changes in the magnitude of the chemosensitive response in LC neurons. Alternatively, Ca2+ and Ca2+ channels may play a role in the response to hypercapnia, but little is known about the role of Ca2+ in central chemosensitivity. Whole cell patch clamp and fluorescence imaging microscopy were used to study a different basis for the developmental changes in the chemosensitive response of LC neurons, a “braking” pathway. In the presence of tetrodotoxin (TTX-inhibitor of Na+ channels), currents composed of both a rhythmic cycling (SRO-subthreshold rhythmic oscillation) and voltage-sensitive spikes were observed. These currents developed over the first 10 postnatal days. Since both currents were abolished by the L-type Ca2+ channel inhibitor nifedipine, both were assumed to be due to the activity of L-type Ca2+ channels. Hypercapnia increased the frequency of oscillations and the accompanying spikes in a HCO3--dependent but pH-independent fashion. Voltage clamp studies supported the presence of L-type Ca2+ currents in LC neurons that increased in postnatal rats aged P3 to P12 and were enhanced by hypercapnia, resulting in increased intracellular Ca2+ (Ca2+i). Hypercapnia activated Ca2+ channels in LC neurons via a HCO3--dependent pathway involving soluble adenylate cyclase-cAMP-channel phosphorylation. The hypercapnic increase in Ca2+i activated hyperpolarizing Ca2+-activated K+ currents (KCa). The BK (a large conductance KCa) channel inhibitor paxilline and voltage clamp were used to study this KCa current. Inhibition of the BK current removed the “brake” and increased the firing rate response to hypercapnia in LC neurons. Notably, the “braking” pathway increased during (open full item for complete abstract)

Committee: Robert W. Putnam PhD (Committee Chair); Christopher N. Wyatt PhD (Committee Member); Lynn K. Hartzler PhD (Committee Member); Lawrence J. Prochaska PhD (Committee Member); Timothy C. Cope PhD (Committee Member); Bradley S. Jacobs MD (Committee Member) Subjects: Biomedical Research; Biophysics; Cellular Biology; Neurobiology; Neurosciences; Physiology

Master of Science, The Ohio State University, 2012, Mathematics

There are important differences between pediatric and adult sleep. This research focuses on two challenges arising from these differences. First, why do children not awaken when a fire alarm sounds during sleep? More specifically, children are significantly less likely to awaken to a residential tone smoke alarm during slow wave sleep compared to adults, yet they almost always wake up when a parent's voice calls their name. To study this question, I developed a schematic diagram describing my hypothesis for the biological mechanisms behind this phenomenon. A mathematical model could be developed in future work. A second question is whether loop gain of the ventilatory control system is a good predictor of a suppression of Cheyne-Stokes respiration with continuous positive airway pressure (CPAP) in pediatric patients. A novel technique was previously developed for calculating loop gain from duty ratio, leading to the hypothesis that loop gain is a distinguishing factor between adult patients who did and did not respond to CPAP. This research examines if the same technique will work with pediatric patients. I applied the technique to sleep data from a pediatric patient with periodic breathing and calculated an elevated loop gain beyond the threshold for response to CPAP. The effectiveness of CPAP in this child raises the question whether this same method is applicable to children. A study of the loop gain formula suggests that children in general do not have a higher loop gain, but rather this patient's high loop gain is due to other previous conditions.

Committee: Janet Best PhD (Advisor); Mark Splaingard MD (Committee Member); Ching-Shan Chou PhD (Committee Member) Subjects: Applied Mathematics