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

Intubation for acute respiratory illness that often leads to acute respiratory distress syndrome (ARDS) is a common threat to the pediatric population worldwide and at the project site pediatric intensive care unit (PICU). The length of mechanical ventilation is a multifactorial determination for each patient circumstance and is strongly associated with the extensiveness of the respiratory illness. Literature supports postural drainage (PD) positioning as a form of treatment for respiratory illness and ARDS, but it is not a common modality utilized in the project site PICU. Using evidence of best positioning practices for lung health, a two-stepped protocol for patient positioning was developed and implemented based on the severity level of ARDS to decrease the length of mechanical ventilation. The application of the positioning protocol for patients that met inclusion criteria demonstrated notable fluid shifting and decreased opacities on chest radiography, a consistent gradual decline in ventilator pressures, oxygen requirement, and ARDS severity levels, and a decrease in the average length of mechanical ventilation. This evidence-based quality improvement initiative provided a strong testimonial to the value of using PD positioning as a treatment method for patients intubated due to respiratory illness and ARDS.

Committee: Kristin Clephane (Advisor) Subjects: Health Care; Nursing

Master of Sciences (Engineering), Case Western Reserve University, 2024, Biomedical Engineering

The Ulnar Collateral Ligament, one of the main stabilizers of the elbow joint, provides valgus stability during the act of overhead arm movements. An injury to this ligament can lead to pain and significant time off due to the duration of rehabilitation required to regain neuromuscular deficits. Current rehabilitation approaches for UCL tears involve subjective assessments (pain scales) and objective measures. However, there still remains a lack of ongoing, continuous monitoring of collegiate baseball athletes during their season to both better understand and predict athlete performance and injury risk at this level. The objective of this study was to assess possible biomarkers that can monitor internal and continuous physiologic data and track internal training load for baseball athletes. The aim was to design an experimental protocol which can determine the performance of the kinetic chain of overhead throwing. A pilot clinical trial was conducted with the long-term goal of developing a reconstruction training tolerance model for athletes whose sports perform the same repetitive overarm movement mechanics. However, a single unique biomarker was not established.

Committee: Colin Drummond (Advisor); Dhruv Seshadri (Committee Member); Shanina Knighton (Committee Member); Christopher Pulliam (Committee Chair) Subjects: Biomedical Engineering

Doctor of Philosophy (PhD), Wright State University, 2021, Engineering PhD

The research presented in this dissertation focused on the application of optical imaging techniques to establish blood flow and oxygen saturation as effective biomarkers for two disease cases, Autism Spectrum Disorder (ASD) and Huntington's Disease (HD). The BTBR mouse model of ASD was utilized to validate measurements of cerebral blood flow and oxygenation as biomarkers for autism. The R6/2 mouse model of juvenile HD was utilized to validate measurements of skeletal muscle blood flow following tetanic muscle contractions induced by electrical nerve stimulation. Next, a noncontact, camera-based system to measure blood flow and oxygen saturation maps was implemented to improve upon the previous HD mouse results by providing spatial heterogeneity in a wild-type mouse model. Finally, translational research was performed to validate a research design conducting concurrent grip strength force and skeletal muscle blood flow and oxygenation measurements in a healthy human population that will be used to establish HD biomarkers in humans in future clinical applications.

Committee: Ulas Sunar Ph.D. (Advisor); Andrew Voss Ph.D. (Committee Member); Sandra Kostyk M.D., Ph.D. (Committee Member); Tarun Goswami Ph.D. (Committee Member); Mark Rich Ph.D. (Committee Member) Subjects: Biomedical Engineering; Biomedical Research; Medical Imaging; Optics

Master of Science, Miami University, 2021, Physics

Diffuse optical spectroscopy (DOS) is a widely used non-invasive technique to study the morphology and function of biological tissues. DOS measurements are usually acquired using fiber-based measurements of diffuse reflectance which are then analyzed using theoretical models of photon propagation to compute the absorption and scattering coefficients. These optical properties in turn can be related to important physiological parameters, such as hemoglobin concentration or oxygen saturation. Diffusion theory (DT) is widely utilized for quantifying DOS reflectance measurements from biological tissues given its compact analytic nature, but DT represents the tissue media using homogeneous optical properties. Many biological tissues, such as brain, have layered structure with inhomogeneous optical properties. Monte Carlo (MC) methods are also widely utilized rigorous solvers for photon transport in turbid media which can easily be used to incorporate spatial heterogeneity in the medium. In this study, two-layered slab tissue models will be utilized to simulate diffuse reflectance at multiple wavelengths. By analyzing reflectance spectra using DT, the accuracy of the diffusion theory to estimate physiological parameters will be studied.

Committee: Karthik Vishwanath Dr. (Advisor); Paul Urayama Dr. (Committee Member); Imran Mirza Dr. (Committee Member) Subjects: Physics

Master of Sciences (Engineering), Case Western Reserve University, 2021, EECS - Electrical Engineering

The rise of wearable technology has enabled continuous fitness and health monitoring. Continuous health monitoring is seen as a very powerful tool for preventative health care. The development of advanced sensors and better devices allow for more comprehensive monitoring and wider adoption. Wearable devices commonly use PPG based pulse oximetry to measure heart rate and oxygen saturation, two very important health metrics, although limitation in their design prevent them from being very practical from a health monitoring perspective. This research presents the design and development of a novel wearable pulse oximeter device that attempts to overcome limitations of existing devices. All aspects of the device design including mechanical form factor, electrical circuit and embedded software are covered in length. The resulting device, Earox, is an ear-based design that clips on the ear lobe to continuously monitor heart rate and oxygen saturation for two weeks on a single charge.

Committee: Kenneth Loparo (Committee Chair); Nicholas Barendt (Committee Member); Farhad Kaffashi (Committee Member) Subjects: Electrical Engineering; Medical Imaging

MS, Kent State University, 2017, College of Education, Health and Human Services / School of Health Sciences

Due to the anaerobic nature of high-intensity exercise, different altitudes should not affect high-intensity exercise performance. However, it is unclear if repeated bouts of high-intensity anaerobic exercise at high altitude will cause a reduction in power output, when compared to sea level. PURPOSE: To determine the impact of altitude (10,000 ft. above sea level) on power output, and blood lactate, following repeated 30-s high-intensity exercise compared to sea level in anaerobically trained individuals. METHODS: Seven resistance-trained (mean±SD; aged: 23±3 yrs; weight: 81.0±5.0 kg; height: 180.3±3.9 cm; BMI: 24.9±1.6) men (n=7) with a minimum of 6 months of resistance training volunteered for the study. Participants performed three 30-s Wingate Anaerobic Tests (WATs) with 7.5% of bodyweight as the load on a cycle ergometer in both simulated altitude and sea level. Altitude was simulated using a normobaric hypoxic chamber with the partial pressure of oxygen set at 13%. Oxygen saturation (SaO2) was measured at baseline and after each WAT. Peak power output, relative peak power output, average power output, average RPM, blood lactate levels, and SaO2 levels were measured following each WAT. Three minutes of active recovery were performed with no load on the cycle ergometer following each WAT. Data were analyzed with a repeated measures ANOVA to examine the effects of power (WAT1, WAT2, and WAT3) by condition (hypoxic and normoxic). Paired t-tests were used for post-hoc testing. Statistical significance was set at p=0.05. RESULTS: There were no significant interactions for any variable. There were also no main effects of condition. SaO2 was not different between the groups at any time point but did decrease after each WAT for each condition. There were significant main effects of time for absolute (WAT1: 876±1336Watts (W); WAT2: 733±127W; WAT3: 635±117W, p=0.0001) and relative (WAT1: 10.8±1.9W; WAT2: 9.0±1.8W; WAT3: 7.8±1.5W, p=0.001) peak power su (open full item for complete abstract)

Committee: J. Derek Kingsley Ph.D. (Advisor) Subjects: Anatomy and Physiology; Kinesiology; Physiology

Doctor of Philosophy, The Ohio State University, 2016, Biomedical Engineering

Cardiovascular disease impacts systemic and organ-specific oxygen supply and extraction. An accurate measurement of blood oxygen saturation (O2 sat) in the heart and major blood vessels is therefore an important biomarker in the clinical evaluation and characterization of cardiovascular disease. Currently, the standard method of obtaining this measurement is by invasive catheterization, which carries significant risks. Although efforts have been made to develop surrogate markers and non-invasive measurement techniques, they cannot replace the clinical significance of a measurement of mixed venous O2 sat in the heart. Therefore, the focus of this research was to develop a truly non-invasive imaging technique to estimate oxygen saturation in the heart. Magnetic resonance (MR) methods to determine blood oxygen saturation have been proposed, tried, and tested for the past twenty-five years. Numerous assumptions are involved in the determination of blood O2 sat from MR relaxation times. As such, transverse relaxation (T2) based MR oximetry techniques rely on technique-specific and patient-specific in vitro calibration in order to reduce the variability arising from these assumptions. However, these impractical requirements have hindered the widespread application of these techniques, and have prevented them from gaining clinical acceptance. Cardiovascular physiology and pathophysiology, and MR imaging physics was reviewed to identify the clinical need as well as the potential engineering pathways to develop a reliable, clinically useful solution to non-invasively estimate blood O2 sat. The result is a technique that augments the diagnostic potential of the MR evaluation of cardiovascular diseases such as congenital heart disease, heart failure and pulmonary hypertension. The novel concept presented in this research work obviates the need for an in vitro calibration process required by previously proposed T2 based MR oximetry methods, and provides a more reliab (open full item for complete abstract)

Committee: Orlando Simonetti PhD (Advisor); Subha Raman MD, MSEE (Committee Member); Jun Liu PhD (Committee Member); Rizwan Ahmad PhD (Committee Member); Ning Jin PhD (Committee Member) Subjects: Biomedical Engineering

MA, University of Cincinnati, 2009, Arts and Sciences : Psychology

This study compared measures of cerebral blood flow velocity (CBFV) and blood oxygen saturation (rSO2), during the performance of a 40-min vigilance task. Observers monitored a simulated air-traffic control display for flight path deviations which occurred in a unidirectional or a multidirectional context. CBFV and rSO2 measures were secured from the medial cerebral arteries in the left and right cerebral hemispheres and from the corresponding frontal lobes, respectively.Performance efficiency was greater in the unidirectional than the multidirectional condition and declined over time in both conditions, more so in the multidirectional condition. This pattern of results was paralleled in different ways by the two hemodynamic measures. A result of this sort challenges the assumption of a close tie between cerebral blood flow and oxygen saturation (Siesjo, 1978) and supports recent findings (Mintun et al., 2001) that cerebral blood flow and oxygen levels are not tightly coupled in active brain states.

Committee: Gerald Matthews PhD (Committee Chair); Michael Riley PhD (Committee Member); Joel Warm PhD (Committee Member) Subjects: Experiments

PhD, University of Cincinnati, 2007, Arts and Sciences : Psychology

Gravity-induced loss of consciousness (GLOC) is a major psychophysiological threat to pilots of high-performance aircraft that has resulted in substantial loss of life and equipment (Albery &Van Patten, 1991). It is brought about by a sudden reduction in cerebral blood flow and subsequent decrease in cerebral tissue O2 as a result of increased +Gz force (McKinley, Tripp, Bolia, & Roark, 2005). During such episodes, pilots are totally incapacitated for 24 sec. They are unconscious for half of that time (the absolute incapacitation period) and confused for the remainder (the relative incapacitation period; Whinnery, Burton, Boll, & Eddy, 1987). In addition, evidence is available to indicate that cognitive and psychomotor functions are compromised several sec prior to the onset of unconsciousness and for 55.50 sec after confusion subsides (Tripp et al., 2006). Using centrifuge simulators to induce GLOC and math and tracking tasks to emulate flight performance, three experiments were conducted to determine if reductions in the rate of G-suit deflation (Experiment 1), the application of supplementary sensory stimulation (Experiment 2), and the employment of negative Gz offset profiles (Experiment 3) could be of effective value in reducing the duration of the GLOC epoch. All three experiments produced statistically significant reductions in the duration of the epoch, but these reductions were too small to be of practical utility in an operational setting. Experiment 3 also featured the use of near-infrared cerebral oximetry to track the course of cerebral tissue O2 levels in a GLOC-inducing experimental session. The results indicated that O2 levels dropped precipitously from baseline after the onset of Gz acceleration with performance deterioration beginning and GLOC appearing when the O2 levels fell to 95 percent and 80 percent of baseline, respectively. Cerebral oxygen levels rose quickly after the termination of acceleration and returned to baseline well before partici (open full item for complete abstract)

Committee: Dr. Joel Warm (Advisor) Subjects: Psychology, Cognitive